Kenneth W Liechty

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• Liechty, K. (2011). Omphalocele. In Fundamentals of Pediatric Surgery, Second Edition. Springer New York. doi:10.1007/978-1-4419-6643-8_66
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  Omphalocele is a common congenital abdominal wall defects. It consists of a central defect in the umbilical ring that allows herniation of the viscera into the umbilical cord, resulting in a membrane-covered defect. The mortality has been historically reported to exceed 25%, however this has been reduced by advances in prenatal diagnosis, pediatric anesthesia, mechanical ventilation, nutritional support, operative techniques, and neonatal intensive care units. © 2011 Springer Science+Business Media, LLC.

Journals/Publications

• Eason, C. R., Dawson-Gore, C., Buted, S., Weikel, B. W., Vaughn, A. E., Zaretsky, M., Meyers, M. L., Gien, J., Liechty, K. W., & Derderian, S. C. (2026). Right-sided congenital diaphragmatic hernia: Characterization, utility of prenatal imaging predictors and outcomes. Journal of pediatric surgery, 61(1), 162734.
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  Identify the most accurate prenatal predictor of survival for infants with right-sided congenital diaphragmatic hernia (R-CDH), analyze management strategies and outcomes and evaluate differences in outcomes based on surgical repair techniques.
• Eason, C. R., Dawson–Gore, C., Buted, S., Weikel, B. W., Vaughn, A. E., Zaretsky, M., Meyers, M. L., Gien, J., Liechty, K. W., & Derderian, S. C. (2026). Right-sided congenital diaphragmatic hernia: Characterization, utility of prenatal imaging predictors and outcomes. Journal of Pediatric Surgery, 61(Issue 1). doi:10.1016/j.jpedsurg.2025.162734
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  Purpose: Identify the most accurate prenatal predictor of survival for infants with right-sided congenital diaphragmatic hernia (R-CDH), analyze management strategies and outcomes and evaluate differences in outcomes based on surgical repair techniques. Methods: We conducted a retrospective review of infants diagnosed with R-CDH at a single institution from 2010 to 2024. Prenatal ultrasound and MRI values were analyzed to predict survival as well as secondary outcomes including need for extracorporeal membrane oxygenation (ECMO), duration on mechanical ventilation, length of hospitalization (LOH), and severity of pulmonary hypertension. Outcomes between repair techniques were compared in a subgroup analysis. Results: Thirty-two infants with R-CDH met inclusion criteria. Overall survival to discharge was 75 %. Seventeen (53 %) had prenatal imaging and were diagnosed prenatally. Among ultrasound and MRI prenatal predicitive indices, no thresholds to accurately distinguish survivors from non-survivors were identified. All but one infant diagnosed prenatally required ECMO. Nine (28 %) underwent primary repair, nine (28 %) were repaired with a synthetic patch, and 14 (44 %) with a transversus abdominus muscle flap. Infants with patch repairs required reoperation for a bleeding complication more often than those repaired with a muscle flap [5 (56 %) versus 1 (7 %), p = 0.02]. Conclusion: No prenatal indicator of disease severity accurately predicted survival. Patch and muscle flap repair are both accepted techniques to repair R-CDH defects. All but one infant diagnosed prenatally with R-CDH required ECMO, underscoring the critical need for delivery at a tertiary care center equipped with ECMO capabilities.
• Bolouvi, E. H., Seckeler, M. D., Price, A., Morgan, W., Lightwine, B., & Liechty, K. W. (2025). Management of severe left main bronchomalacia in an infant with a balloon expandable bare metal coronary stent: a case report. Journal of Pediatric Surgery Case Reports, 120(Issue). doi:10.1016/j.epsc.2025.103042
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  Introduction: Managing bronchomalacia in infants represents a significant challenge. Surgical strategies such as aortopexy and tracheopexy have variable outcomes in distal airway disease. Stent placement is typically reserved as a last resort in selected cases. Case presentation: A 4-month-old ex-34-weeker infant status-post neonatal repair of a large omphalocele was re-intubated six weeks post-operatively for severe respiratory distress. Despite escalating positive-end expiratory pressure, bronchodilators, and airway clearance, the respiratory function continued to decline. Bronchoscopy showed severe left main bronchomalacia and bronchial stenosis, confirmed by chest computerized tomography (CT). There was near complete occlusion of the left main bronchus, but with patent distal airway. A 4.5 mm × 15 mm bare metal coronary stent (Resolute Onyx Frontier) was placed in the left main bronchus under fluoroscopic and bronchoscopic guidance. This led to an immediate improvement in lung mechanics, with subsequent extubation. The stent was electively removed after 11 weeks. However, re-occlusion occurred within 24 hours due to airway compression, which was managed with the placement of a second stent (5 mm × 15 mm). The symptoms resolved completely, and the patient was discharged home at the age of 10 months. He was subsequently managed at a different hospital. At the age of 14 months the stent was removed. Shortly after the removal, he had a recurrence of the left lung collapse and a respiratory infection requiring extracorporeal membrane oxygenation (ECMO). An 8 mm × 20 mm stent was then placed to recruit the left lung and allow ECMO decannulation. He remains with the stent in place. Conclusion: Bare metal coronary stents appear to be an effective temporizing management option for infants with severe bronchomalacia who fail standard non-operative measures, allowing time for the airway to become more rigid.
• Chenchar, A., Mattos Pereira, V., Apte, A., Lyttle, B. D., Vaughn, A. E., Lehmann, T., Bardill, J. R., Zgheib, C., Liechty, K. W., Roballo, K. C., Zhang, Z., Alexander, B. M., & Nair, S. (2025). Targeting Cathepsin K to Accelerate Diabetic Wound Healing. ACS pharmacology & translational science, 8(7), 2258-2269.
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  : Elevated protease activity impairs wound healing. Cathepsin K is a cysteine protease with potent collagenolytic and elastolytic activity. This study examined the effects of odanacatib, a cathepsin K inhibitor, on wound healing in a diabetic porcine model. Additionally, it assessed whether the genetic deletion of cathepsin K improves wound healing in diabetic mice. : Three cohorts of three-month-old female Yorkshire pigs (eight to ten pigs per cohort) were rendered diabetic via intravenous injections of streptozotocin (STZ, 75 mg/kg). After 4 weeks, ten full-thickness (∼300 μm) excisional skin wounds, each measuring one square inch, were created on the dorsal surface of each animal. The wounds were treated with either vehicle or odanacatib (30 or 300 ng/mm) via intradermal injection on days 0, 3, 7, and 14. For mouse studies, diabetes was induced in cathepsin K knockout ( and wild-type C57BL/6 mice via STZ injections, and a single full-thickness excisional wound was created on each mouse. The wounds were photographed and assessed on days 0, 7, 14, 21, and daily until complete closure. Wound healing progression was evaluated by measuring wound closure rates, CD31 expression, and histology. An in vitro scratch assay was utilized to assess the effect of odanacatib on the migration of cultured skin fibroblasts and keratinocytes under high-glucose conditions. : Odanacatib treatment significantly accelerated wound closure in diabetic pigs, promoting epithelialization and ECM stability. Similarly, diabetic Ctsk mice exhibited improved healing compared to wild-type controls. In vitro, odanacatib increased the migration of fibroblasts and keratinocytes under hyperglycemic conditions. : This study is the first to demonstrate that inhibiting cathepsin K, either genetically or pharmacologically, improves diabetic wound healing. These findings position cathepsin K as a promising therapeutic target for the treatment of chronic wounds.
• Chenchar, A., Pereira, V. M., Apte, A., Lyttle, B. D., Vaughn, A. E., Lehmann, T., Bardill, J. R., Zgheib, C., Liechty, K. W., Roballo, K. C., Zhang, Z., Alexander, B. M., & Nair, S. (2025). Targeting Cathepsin K to Accelerate Diabetic Wound Healing. ACS Pharmacology and Translational Science, 8(Issue 7). doi:10.1021/acsptsci.5c00295
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  Objective: Elevated protease activity impairs wound healing. Cathepsin K is a cysteine protease with potent collagenolytic and elastolytic activity. This study examined the effects of odanacatib, a cathepsin K inhibitor, on wound healing in a diabetic porcine model. Additionally, it assessed whether the genetic deletion of cathepsin K improves wound healing in diabetic mice. Approach: Three cohorts of three-month-old female Yorkshire pigs (eight to ten pigs per cohort) were rendered diabetic via intravenous injections of streptozotocin (STZ, 75 mg/kg). After 4 weeks, ten full-thickness (∼300 μm) excisional skin wounds, each measuring one square inch, were created on the dorsal surface of each animal. The wounds were treated with either vehicle or odanacatib (30 or 300 ng/mm2) via intradermal injection on days 0, 3, 7, and 14. For mouse studies, diabetes was induced in cathepsin K knockout (Ctsk-/-) and wild-type C57BL/6 mice via STZ injections, and a single full-thickness excisional wound was created on each mouse. The wounds were photographed and assessed on days 0, 7, 14, 21, and daily until complete closure. Wound healing progression was evaluated by measuring wound closure rates, CD31 expression, and histology. An in vitro scratch assay was utilized to assess the effect of odanacatib on the migration of cultured skin fibroblasts and keratinocytes under high-glucose conditions. Results: Odanacatib treatment significantly accelerated wound closure in diabetic pigs, promoting epithelialization and ECM stability. Similarly, diabetic Ctsk-/- mice exhibited improved healing compared to wild-type controls. In vitro, odanacatib increased the migration of fibroblasts and keratinocytes under hyperglycemic conditions. Innovation and Conclusion: This study is the first to demonstrate that inhibiting cathepsin K, either genetically or pharmacologically, improves diabetic wound healing. These findings position cathepsin K as a promising therapeutic target for the treatment of chronic wounds.
• Credille, C., Eason, C. R., Evans, L. L., Bothwell, S., Gien, J., Vaughn, A. E., Kinsella, J. P., Varma, P., Liechty, K. W., & Christopher Derderian, S. (2025). Bleeding Complications between Bivalirudin and Heparin for Extracorporeal Membrane Oxygenation in Neonates with Congenital Diaphragmatic Hernia. Fetal Diagnosis and Therapy, 52(Issue 2). doi:10.1159/000542760
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  Introduction: Neonates with congenital diaphragmatic hernia (CDH) who undergo repair while on extracorporeal membrane oxygenation (ECMO) are at risk of developing post-operative bleeding complications. Balanced anticoagulation is critical to maintain ECMO flow and avoid bleeding. Heparin has historically been our first-line anticoagulant; however, recently, we transitioned to bivalirudin, a direct thrombin inhibitor. The objective of this pilot study was to compare post-operative surgical bleeding complications between the two groups. Methods: We performed a single center retrospective cohort study of patients who underwent CDH repair while on ECMO between 2008 and 2023. Neonates were stratified based on the type of anticoagulant initiated after CDH repair. Outcomes included bleeding requiring surgical re-operation, intracranial hemorrhage, volume of blood products transfused, number of circuit changes, days on ECMO, and overall survival. Results: Among 62 neonates with CDH who underwent repair on ECMO, 44 (71%) were managed post-CDH repair with heparin and 18 (29%) with bivalirudin. One (5.6%) neonate managed with bivalirudin underwent re-operation following CDH repair for a bleeding complication compared to 17 (38.6%) managed with heparin (p = 0.022). In addition, the bivalirudin cohort utilized half of the total blood product volume compared to the heparin cohort (p = 0.020). Despite these benefits, there were no significant differences between groups for incidence of intracranial hemorrhage, number of circuit changes, days on ECMO, and overall survival. Conclusion: Anticoagulation with bivalirudin in neonates who underwent CDH repair while on ECMO was associated with decreased surgical bleeding complications and less total blood product transfused. This pilot analysis is the first to compare heparin to bivalirudin and stresses the importance of a multicenter study.
• Credille, C., Eason, C. R., Evans, L. L., Bothwell, S., Gien, J., Vaughn, A. E., Kinsella, J. P., Varma, P., Liechty, K. W., & Derderian, S. C. (2025). Bleeding Complications between Bivalirudin and Heparin for Extracorporeal Membrane Oxygenation in Neonates with Congenital Diaphragmatic Hernia. Fetal diagnosis and therapy, 52(2), 133-138.
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  Neonates with congenital diaphragmatic hernia (CDH) who undergo repair while on extracorporeal membrane oxygenation (ECMO) are at risk of developing post-operative bleeding complications. Balanced anticoagulation is critical to maintain ECMO flow and avoid bleeding. Heparin has historically been our first-line anticoagulant; however, recently, we transitioned to bivalirudin, a direct thrombin inhibitor. The objective of this pilot study was to compare post-operative surgical bleeding complications between the two groups.
• Elajaili, H., Lyttle, B. D., Lewis, C. V., Bardill, J. R., Dee, N., Seal, S., Nozik, E. S., Liechty, K. W., & Zgheib, C. (2025). Increased ROS and Persistent Pro-Inflammatory Responses in a Diabetic Wound Healing Model (db/db): Implications for Delayed Wound Healing. International Journal of Molecular Sciences, 26(Issue 10). doi:10.3390/ijms26104884
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  Diabetes and its complications, including impaired wound healing, present a critical clinical challenge and burden for the U.S. healthcare system, with costs of over USD 13 billion annually. Hyperglycemia and chronic inflammation in diabetic wounds increase reactive oxygen species (ROS) production, inducing oxidative stress and perpetuating inflammation, which delays healing. This study investigates inflammation, oxidative stress, and the roles of cellular populations in a diabetic wound healing mouse model (db/db). Given that diabetes leads to persistent inflammation and impaired fibroblast function, we also examined how diabetes influences superoxide production in dermal fibroblasts. Blood, dermal fibroblasts, and wound tissue were collected from 12-week-old female diabetic (Db) and heterozygous (Hz) mice. Electron paramagnetic resonance (EPR) spectroscopy revealed higher superoxide levels in diabetic blood, dermal fibroblasts, and wounds compared to controls. In diabetic wounds, immunohistochemistry and flow cytometry showed increased leukocyte infiltration and reduced macrophage presence, with a higher proportion of pro-inflammatory Ly6Chi macrophages. These results suggest that elevated superoxide production and persistent inflammation contribute to impaired fibroblast function and delayed wound healing in diabetes. By identifying the contributions of ROS and Ly6Chi macrophages to oxidative stress and chronic inflammation, this study offers insights into therapeutic strategies. These findings highlight the importance of addressing systemic oxidative stress alongside localized inflammation to improve wound healing outcomes in diabetic patients and advance diabetic wound care strategies.
• Hsia, H. C., Eriksson, E., Gurtner, G. C., Veves, A., Hamdy, O., Margolis, D. J., Armstrong, D. G., Lavery, L. A., Grice, E. A., Schultz, G., Conte, M. S., Kirsner, R. S., Attinger, C. E., Steinberg, J. S., Evans, K. K., Weir, D., Kim, P. J., Orgill, D. P., Liechty, K. W., & Rubin, J. P. (2025). Management of Diabetic Wounds: Expert Panel Consensus Statement. Advances in wound care.
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  The Wound Healing Foundation recognized the need for consensus-based unbiased recommendations for the treatment of wounds. Consensus statements on the treatment of chronic wounds and acute wounds have been developed and published previously. The current publication on diabetic wounds represents the next step in this process. Diabetic wounds constitute a major problem. Population-based and meta-analytic studies indicate that the presence of foot wounds in patients with diabetes increases their mortality risk by more than twofold. The management of diabetic wounds requires consistent and evidence-driven intervention to achieve optimal clinical outcomes. This consensus statement provides the clinician with the necessary foundational approaches to the causes, diagnosis, and therapeutic management of diabetic wounds. Presented in a structured format, this is a useful guide for clinicians and learners in all patient care settings. Continuous glucose monitoring and other new tools have facilitated better diabetes management and the management of associated wounds. Diabetic limb salvage should focus on achieving and optimizing function for the patient with diabetes rather than preserving limb tissue at all costs. Successful management of diabetic wounds requires a multidisciplinary approach encompassing comprehensive assessment, timely intervention, and collaborative care by the wound clinician with providers who can address critical aspects to achieve healing, including careful management of blood glucose levels, optimization of off-loading and physical therapy, assessment and treatment of limb ischemia, control and prevention of wound infection, and optimal pain management. Emerging treatments offer hope and promise, but the heterogenicity of diabetic wounds poses a challenge to performing good studies, which will be necessary to advance new treatments for diabetic wounds.
• Apte, A., Bardill, J. R., Canchis, J., Skopp, S. M., Fauser, T., Lyttle, B., Vaughn, A. E., Seal, S., Jackson, D. M., Liechty, K. W., & Zgheib, C. (2024). Targeting Inflammation and Oxidative Stress to Improve Outcomes in a TNBS Murine Crohn's Colitis Model. Nanomaterials (Basel, Switzerland), 14(10).
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  Inflammation and oxidative stress are implicated in the pathogenesis of Crohn's disease. Cerium oxide nanoparticle (CNP) conjugated to microRNA 146a (miR146a) (CNP-miR146a) is a novel compound with anti-inflammatory and antioxidative properties. We hypothesized that local administration of CNP-miR146a would improve colitis in a 2,4,6-Trinitrobenzenesulfonic acid (TNBS) mouse model for Crohn's disease by decreasing colonic inflammation. Balb/c mice were instilled with TNBS enemas to induce colitis. Two days later, the mice received cellulose gel enema, cellulose gel with CNP-miR146a enema, or no treatment. Control mice received initial enemas of 50% ethanol and PBS enemas on day two. The mice were monitored daily for weight loss and clinical disease activity. The mice were euthanized on days two or five to evaluate their miR146a expression, inflammation on histology, and colonic IL-6 and TNF gene expressions and protein concentrations. CNP-miR146a enema successfully increased colonic miR146a expression at 12 h following delivery. At the end of five days from TNBS instillation, the mice treated with CNP-miR146a demonstrated reduced weight loss, improved inflammation scores on histology, and reduced gene expressions and protein concentrations of IL-6 and TNF. The local delivery of CNP-miR146a in a TNBS mouse model of acute Crohn's colitis dramatically decreased inflammatory signaling, resulting in improved clinical disease.
• Apte, A., Dutta Dey, P., Julakanti, S. R., Midura-Kiela, M., Skopp, S. M., Canchis, J., Fauser, T., Bardill, J., Seal, S., Jackson, D. M., Ghishan, F. K., Kiela, P. R., Zgheib, C., & Liechty, K. W. (2024). Oral Delivery of miR146a Conjugated to Cerium Oxide Nanoparticles Improves an Established T Cell-Mediated Experimental Colitis in Mice. Pharmaceutics, 16(12).
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  Dysregulated inflammation and oxidative stress are strongly implicated in the pathogenesis of inflammatory bowel disease. We have developed a novel therapeutic that targets inflammation and oxidative stress. It is comprised of microRNA-146a (miR146a)-loaded cerium oxide nanoparticles (CNPs) (CNP-miR146a). We hypothesized that oral delivery of CNP-miR146a would reduce colonic inflammation in a mouse model of established, chronic, T cell-mediated colitis. The stability of CNP-miR146a and mucosal delivery was assessed in vitro with simulated gastrointestinal fluid and in vivo after oral gavage by quantitative real-time RT-PCR. The efficacy of orally administered CNP-miR146a was tested in mice with established colitis using the model of adoptive naïve T-cell transfer in recombinant activating gene 2 knockout (Rag2) mice. Measured outcomes included histopathology; CD45 immune cell infiltration; oxidative DNA damage (tissue 8-hydroxy-2'-deoxyguanosine; 8-OHdG); expression of IL-6 and TNF mRNA and protein, and flow cytometry analysis of lamina propria Th1 and Th17 cell populations. miR146a expression remained stable in simulated gastric and intestinal conditions. miR146a expression increased in the intestines of mice six hours following oral gavage of CNP-miR146a. Oral delivery of CNP-miR146a in mice with colitis was associated with reduced inflammation and oxidative stress in the proximal and distal colons as evidenced by histopathology scoring, reduced immune cell infiltration, reduced IL-6 and TNF expression, and decreased populations of CD4TbetIFNg+ Th1, CD4RorgTIL17 Th17, as well as pathogenic double positive IFNgIL17 T cells. : CNP-miR146a represents a novel orally available therapeutic with high potential to advance into clinical trials.
• Apte, A., Dutta Dey, P., Julakanti, S. R., Midura-Kiela, M., Skopp, S. M., Canchis, J., Fauser, T., Bardill, J., Seal, S., Jackson, D. M., Ghishan, F. K., Kiela, P. R., Zgheib, C., & Liechty, K. W. (2024). Oral Delivery of miR146a Conjugated to Cerium Oxide Nanoparticles Improves an Established T Cell-Mediated Experimental Colitis in Mice. Pharmaceutics, 16(Issue 12). doi:10.3390/pharmaceutics16121573
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  Background: Dysregulated inflammation and oxidative stress are strongly implicated in the pathogenesis of inflammatory bowel disease. We have developed a novel therapeutic that targets inflammation and oxidative stress. It is comprised of microRNA-146a (miR146a)-loaded cerium oxide nanoparticles (CNPs) (CNP-miR146a). We hypothesized that oral delivery of CNP-miR146a would reduce colonic inflammation in a mouse model of established, chronic, T cell-mediated colitis. Methods: The stability of CNP-miR146a and mucosal delivery was assessed in vitro with simulated gastrointestinal fluid and in vivo after oral gavage by quantitative real-time RT-PCR. The efficacy of orally administered CNP-miR146a was tested in mice with established colitis using the model of adoptive naïve T-cell transfer in recombinant activating gene 2 knockout (Rag2−/−) mice. Measured outcomes included histopathology; CD45+ immune cell infiltration; oxidative DNA damage (tissue 8-hydroxy-2′-deoxyguanosine; 8-OHdG); expression of IL-6 and TNF mRNA and protein, and flow cytometry analysis of lamina propria Th1 and Th17 cell populations. Results: miR146a expression remained stable in simulated gastric and intestinal conditions. miR146a expression increased in the intestines of mice six hours following oral gavage of CNP-miR146a. Oral delivery of CNP-miR146a in mice with colitis was associated with reduced inflammation and oxidative stress in the proximal and distal colons as evidenced by histopathology scoring, reduced immune cell infiltration, reduced IL-6 and TNF expression, and decreased populations of CD4+Tbet+IFNg+ Th1, CD4+RorgT+IL17+ Th17, as well as pathogenic double positive IFNg+IL17+ T cells. Conclusions: CNP-miR146a represents a novel orally available therapeutic with high potential to advance into clinical trials.
• Apte, A., Fauser, T., Carson, Q., Liechty, K. W., Simpson, L. N., & Avellino, A. M. (2024). In utero Diagnosis of Spinal Dermal Sinus. Fetal diagnosis and therapy, 51(3), 235-242.
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  Congenital dermal sinus (CDS) is an open neural tube defect (NTD) that occurs in 1 in 2,500 births a year and often goes undetected until patients present with complications like infection and neurological deficits. Early diagnosis and repair of CDS may prevent formation of these complications. In utero diagnosis of these lesions may improve long-term outcomes by enabling referral to specialty services and planned postnatal repair; however, only 2 such cases have been reported in the literature. We present a third case of in utero diagnosis of CDS with a description and discussion of findings from surgical exploration and pathology.
• Gallagher, L. T., Bardill, J., Sucharov, C. C., Wright, C. J., Karimpour-Fard, A., Zarate, M., Breckenfelder, C., Liechty, K. W., & Derderian, S. C. (2024). Dysregulation of miRNA-mRNA expression in fetal growth restriction in a caloric restricted mouse model. Scientific reports, 14(1), 5579.
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  Fetal growth restriction (FGR) is associated with aberrant placentation and accounts for a significant proportion of perinatal deaths. microRNAs have been shown to be dysregulated in FGR. The purpose of this study was to determine microRNA-regulated molecular pathways altered using a caloric restricted mouse model of FGR. Pregnant mice were subjected to a 50% caloric restricted diet beginning at E9. At E18.5, RNA sequencing of placental tissue was performed to identify differences in gene expression between caloric restricted and control placentas. Significant differences in gene expression between caloric restricted and control placentas were observed in 228 of the 1546 (14.7%) microRNAs. Functional analysis of microRNA-mRNA interactions demonstrated enrichment of several biological pathways with oxidative stress, apoptosis, and autophagy pathways upregulated and angiogenesis and signal transduction pathways downregulated. Ingenuity pathway analysis also suggested that ID1 signaling, a pathway integral for trophoblast differentiation, is also dysregulated in caloric restricted placentas. Thus, a maternal caloric restriction mouse model of FGR results in aberrant microRNA-regulated molecular pathways associated with angiogenesis, oxidative stress, signal transduction, apoptosis, and cell differentiation. As several of these pathways are dysregulated in human FGR, our findings suggest that this model may provide an excellent means to study placental microRNA derangements seen in FGR.
• Lyttle, B. D., Derderian, S. C., Neuberger, I., Behrendt, N. J., Pickett-Nairne, K., Francom, C. R., Liechty, K. W., & Meyers, M. L. (2024). Comparison of best landmarks for calculating fetal jaw measurements by ultrasound and MRI in micrognathia. Pediatric radiology, 54(11), 1850-1861.
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  Micrognathia can be diagnosed in utero with ultrasound by measuring the jaw index and/or inferior facial angle, though it can be challenging due to fetal positioning. The jaw index can be measured with magnetic resonance imaging (MRI) using the masseter muscle, but indistinct margins can lead to inaccuracy; the easily visualized posterior teeth buds may be a better landmark.
• Vaughn, A. E., Lyttle, B. D., Louiselle, A. E., Cooper, E., Niemiec, S. M., Phillips, R., Hilton, S. A., Kinsella, J. P., Gien, J., Derderian, S. C., & Liechty, K. W. (2024). Muscle Flap Technique Safe for On-ECMO Congenital Diaphragmatic Hernia Repair. Journal of pediatric surgery, 59(5), 962-968.
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  Prosthetic patches (patch) and muscle flaps (flap) are techniques used for repair of congenital diaphragmatic hernia (CDH) with a large defect unamenable to primary closure. We hypothesized that the flap technique for CDH repair while on extra-corporeal membrane oxygenation (on-ECMO) would have decreased bleeding complications compared to patch due to the hemostatic advantage of native tissue.
• Vaughn, A., Lyttle, B., Tran, W., Derderian, S., Liechty, K., & Gien, J. (2024). Surgical Necrotizing Enterocolitis – Can We Predict the Need for Gastrostomy Tube Placement?. Journal of Surgical Research, 295(Issue). doi:10.1016/j.jss.2023.10.009
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  Introduction: Necrotizing enterocolitis (NEC) is a significant cause of morbidity and mortality among extremely premature infants. Approximately 50% of cases progress to surgery, frequently resulting in resection of necrotic bowel and ostomy creation. Premature neonates are at risk for bronchopulmonary dysplasia and feeding failure; surgery in these patients is higher risk. We evaluated the incidence of gastrostomy tube (GT) placement after ostomy reversal in surgical NEC to define a subset of patients who would benefit from concurrent ostomy reversal and GT placement. Methods: A single-center retrospective study of infants with surgical NEC requiring ostomy creation between 2007 and 2021 was performed. Results: Eighty patients met inclusion criteria. A GT was placed in 45/80 (56.3%), of which 3/45 (6.7%) were placed before, 20/45 (44.4%) concurrently with, and 22/45 (48.9%) after ostomy reversal. Between those who did and did not require GT placement, there were no significant differences in gestational age (27 versus 27 wk, P = 0.94) or birth weight (830 g versus 1055 g, P = 0.36). Hospital length of stay was longer in the GT group (128.2 versus 70.9 d, P < 0.0001). Time from ostomy reversal to hospital discharge was shorter when performed concurrently with GT (56 versus 77 d, P = 0.02). There were no differences in short-term or long-term GT related complications based on timing of GT placement. Conclusions: GT placement occurred in approximately 50% of patients with surgical NEC and GT may be accomplished safely at the time of ostomy reversal thus reducing the need for an additional procedure.
• Apte, A., Liechty, K. W., & Zgheib, C. (2023). Immunomodulatory biomaterials on chemokine signaling in wound healing. Frontiers in pharmacology, 14, 1084948.
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  Normal wound healing occurs through a careful orchestration of cytokine and chemokine signaling in response to injury. Chemokines are a small family of chemotactic cytokines that are secreted by immune cells in response to injury and are primarily responsible for recruiting appropriate immune cell types to injured tissue at the appropriate time. Dysregulation of chemokine signaling is suspected to contribute to delayed wound healing and chronic wounds in diseased states. Various biomaterials are being used in the development of new therapeutics for wound healing and our understanding of their effects on chemokine signaling is limited. It has been shown that modifications to the physiochemical properties of biomaterials can affect the body's immune reaction. Studying these effects on chemokine expression by various tissues and cell type can help us develop novel biomaterial therapies. In this review, we summarize the current research available on both natural and synthetic biomaterials and their effects on chemokine signaling in wound healing. In our investigation, we conclude that our knowledge of chemokines is still limited and that many in fact share both pro-inflammatory and anti-inflammatory properties. The predominance of either a pro-inflammatory or anti-inflammatory profile is mostly likely dependent on timing after injury and exposure to the biomaterial. More research is needed to better understand the interaction and contribution of biomaterials to chemokine activity in wound healing and their immunomodulatory effects.
• Gallagher, L. T., Lyttle, B. D., Meyers, M. L., Gien, J., Zaretsky, M. V., Galan, H. L., Behrendt, N., Liechty, K. W., & Derderian, S. C. (2023).

  Fetal lung volumes measured by MRI predict pulmonary morbidity among infants with giant omphaloceles

  . Prenatal Diagnosis, 43(12), 1514-1519. doi:10.1002/pd.6449
• Gallagher, L. T., Wright, C. J., Lehmann, T., Khailova, L., Zarate, M., Lyttle, B. D., Liechty, K. W., & Derderian, S. C. (2023). Angiogenic and Inflammatory microRNA Regulation in a Mouse Model of Fetal Growth Restriction. The Journal of surgical research, 292, 234-238.
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  Fetal growth restriction (FGR) is associated with impaired angiogenesis and chronic inflammation. MicroRNAs (miRs) are short noncoding RNAs that regulate gene expression at the post-transcriptional level by targeting messenger RNA (mRNA) for degradation or by suppressing translation. We hypothesize that dysregulation of miR-15b, an antiangiogenic miR, and miR-146a, an anti-inflammatory miR, are associated with the FGR's pathogenesis.
• Lyttle, B. D., Vaughn, A. E., Bardill, J. R., Apte, A., Gallagher, L. T., Zgheib, C., & Liechty, K. W. (2023). Effects of microRNAs on angiogenesis in diabetic wounds. Frontiers in medicine, 10, 1140979.
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  Diabetes mellitus is a morbid condition affecting a growing number of the world population, and approximately one third of diabetic patients are afflicted with diabetic foot ulcers (DFU), which are chronic non-healing wounds that frequently progress to require amputation. The treatments currently used for DFU focus on reducing pressure on the wound, staving off infection, and maintaining a moist environment, but the impaired wound healing that occurs in diabetes is a constant obstacle that must be faced. Aberrant angiogenesis is a major contributor to poor wound healing in diabetes and surgical intervention is often necessary to establish peripheral blood flow necessary for healing wounds. Over recent years, microRNAs (miRNAs) have been implicated in the dysregulation of angiogenesis in multiple pathologies including diabetes. This review explores the pathways of angiogenesis that become dysregulated in diabetes, focusing on miRNAs that have been identified and the mechanisms by which they affect angiogenesis.
• Lyttle, B., Vaughn, A., Gallagher, L., Jaggers, J., Galan, H., Liechty, K., & Derderian, S. (2023). Successful open fetal resection of a pericardial teratoma: A case report. Journal of Pediatric Surgery Case Reports, 96(Issue). doi:10.1016/j.epsc.2023.102696
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  Introduction: Pericardial teratomas are rare mediastinal tumors that can lead to pericardial effusions with subsequent tamponade physiology and progression to hydrops. While overall outcomes can be favorable, prognosis is poor in the setting of hydrops, particularly at an early gestational age. Case presentation: We present a case in which a 29-year-old female presented at 26 3/7 weeks’ gestation carrying a fetus with a prenatally diagnosed pericardial teratoma. During a period of outpatient monitoring with twice-weekly ultrasounds and echocardiograms, the fetus developed a rapidly expanding pericardial effusion with cardiac compromise, prompting admission. Following admission, the fetus developed early signs of hydrops including ascites and pulmonary effusions at 27 6/7 weeks, and after a multidisciplinary discussion underwent open fetal resection two days later. This resulted in the resolution of hydrops with delivery at 29 3/7 weeks and ultimately neonatal survival without the need for any additional postnatal procedures. Conclusion: In this case report, we discuss current fetal interventions utilized in the management of pericardial teratomas, including the few prior attempts at open fetal resection. We also highlight the potential benefit of open fetal resection in the setting of early hydrops to optimize further in-utero development while simultaneously addressing the tamponade physiology of pericardial teratomas that can lead to hydrops and fetal demise. Here, we demonstrate that open fetal resection is a feasible and effective treatment option for carefully selected patients with pericardial teratomas, particularly in the setting of early hydrops.
• Niemiec, S., Louiselle, A., Phillips, R., Gien, J., Zaretsky, M., Derderian, S., Liechty, K., & Meyers, M. (2023). Third-trimester percentage predicted lung volume and percentage liver herniation as prognostic indicators in congenital diaphragmatic hernia. Pediatric Radiology, 53(3). doi:10.1007/s00247-022-05538-w
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  Background: Over the last two decades, fetal imaging has greatly improved, and new prenatal imaging measurements have been developed to characterize congenital diaphragmatic hernia (CDH) severity. Objective: To determine the best prenatal imaging predictor of postnatal CDH outcomes, including use of extracorporeal membrane oxygenation (ECMO) and in-hospital mortality, with particular attention to the percentage of liver herniation (%LH) as a predictor. Additionally, we sought to guide best practices across hospital systems including improved models of prenatal risk assessment. Materials and methods: We conducted a retrospective review of infants with left CDH who were prenatally diagnosed. We analyzed prenatal imaging measurements including observed-to-expected (O/E) lung-to-head ratio (LHR) on US, percentage predicted lung volume (PPLV) on MRI, and O/E total fetal lung volume (TFLV) and %LH on MRI. We compared prenatal imaging characteristics for infants with (1) in-hospital postnatal mortality and (2) use of ECMO. Then we performed multivariate logistic regression to determine independent predictors of postnatal outcomes. Results: We included 63 infants with a median gestation of 34 weeks at the time of prenatal MRI. Low O/E LHR (31.2 vs. 50, P < 0.0001), PPLV (14.7 vs. 22.6, P < 0.0001) and O/E TLFV (24.6 vs. 38.3, P < 0.0001) and high %LH (15.1 vs. 2.1, P = 0.0006) were associated with worse postnatal outcomes; however, only PPLV was predictive of survival and need for ECMO on multivariable analysis. PPLV survival to discharge model showed an area under the curve (AUC) of 0.93 (95% confidence interval [CI]: 0.86, 0.99), P < 0.0001; and an odds ratio of 68.7 (95% CI: 6.5–2,302), P = 0.003. PPLV need for ECMO model showed AUC = 0.87 (95% CI: 0.78, 0.96), P < 0.0001; and odds ratio = 20.1 (95% CI: 3.1–226.3), P = 0.011. Conclusion: Low O/E LHR, PPLV and O/E TFLV and high %LH in the third trimester are associated with worse postnatal outcomes. PPLV most strongly predicted outcome using a logistic regression model. Percentage of liver herniation was not an independent predictor of outcomes.
• Peddibhotla, S., Caples, K., Mehta, A., Chen, Q. Y., Hu, J., Idlett-Ali, S., Zhang, L., Zgheib, C., Xu, J., Liechty, K. W., & Malany, S. (2023). Triazolothiadiazine derivative positively modulates CXCR4 signaling and improves diabetic wound healing. Biochemical pharmacology, 216, 115764.
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  Development of specific therapies that target and accelerate diabetic wound repair is an urgent need to alleviate pain and suffering and the huge socioeconomic burden of this debilitating disease. C-X-C Motif Chemokine Ligand 12 (CXCL12) also know an stromal cell-derived factor 1α (SDF-1α) is a chemokine that binds the CXC chemokine receptor type 4 (CXCR4) and activates downstream signaling resulting in recruitment of hematopoietic cells to locations of tissue injury and promotes tissue repair. In diabetes, low expression of CXCL12 correlates with impaired wound healing. Activation of CXCR4 receptor signaling with agonists or positive allosteric modulators (PAMs) provides a potential for small molecule therapeutic discovery and development. We recently reported high throughput screening and identification of the CXCR4 partial agonist UCUF-728, characterization of in vitro activity and reduced wound closure time in diabetic mice at 100 μM as a proof-of-concept study. We report here, the discovery of a second chemical scaffold demonstrating increased agonist potency and represented by thiadiazine derivative, UCUF-965. UCUF-965 is a potent partial agonist of β-arrestin recruitment in CXCR4 receptor overexpressing cell line. Furthermore, UCUF-965 potentiates the CXCL12 maximal response in cAMP signaling pathway, activates CXCL12 stimulated migration in lymphoblast cells and modulates the levels of specific microRNA involved in the complex wound repair process, specifically in mouse fibroblasts. Our results indicate that UCUF-965 acts as a PAM agonist of the CXCR4 receptor. Furthermore, UCUF-965 enhanced angiogenesis markers and reduced wound healing time by 36% at 10.0 μM in diabetic mice models compared to untreated control.
• Vaughn, A. E., Lehmann, T., Sul, C., Wallbank, A. M., Lyttle, B. D., Bardill, J., Burns, N., Apte, A., Nozik, E. S., Smith, B., Vohwinkel, C. U., Zgheib, C., & Liechty, K. W. (2023). CNP-miR146a Decreases Inflammation in Murine Acute Infectious Lung Injury. Pharmaceutics, 15(9).
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  Acute respiratory distress syndrome (ARDS) has approximately 40% in-hospital mortality, and treatment is limited to supportive care. Pneumonia is the underlying etiology in many cases with unrestrained inflammation central to the pathophysiology. We have previously shown that CNP-miR146a, a radical scavenging cerium oxide nanoparticle (CNP) conjugated to the anti-inflammatory microRNA(miR)-146a, reduces bleomycin- and endotoxin-induced acute lung injury (ALI) by decreasing inflammation. We therefore hypothesized that CNP-miR146a would decrease inflammation in murine infectious ALI. Mice were injured with intratracheal (IT) MRSA or saline followed by treatment with IT CNP-miR146a or saline control. Twenty-four hours post-infection, bronchoalveolar lavage fluid (BALF) and whole lungs were analyzed for various markers of inflammation. Compared to controls, MRSA infection significantly increased proinflammatory gene expression (IL-6, IL-8, TNFα, IL-1β; < 0.05), BALF proinflammatory cytokines (IL-6, IL-8, TNFα, IL-1β; < 0.01), and inflammatory cell infiltrate ( = 0.03). CNP-miR146a treatment significantly decreased proinflammatory gene expression (IL-6, IL-8, TNFα, IL-1β; < 0.05), bronchoalveolar proinflammatory protein leak (IL-6, IL-8, TNFα; < 0.05), and inflammatory infiltrate ( = 0.01). CNP-miR146a decreases inflammation and improves alveolar-capillary barrier integrity in the MRSA-infected lung and has significant promise as a potential therapeutic for ARDS.
• Vaughn, A. E., Louiselle, A. E., Tong, S., Niemiec, S. M., Ahmad, S., Zaretsky, M., Galan, H. L., Behrendt, N., Wilkinson, C. C., O'Neill, B., Handler, M., Derderian, S. C., Mirsky, D. M., & Liechty, K. W. (2023). Early outcomes of a myofascial repair technique for fetal myelomeningocele. Journal of pediatric surgery, 58(1), 20-26.
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  Fetal repair of myelomeningocele (MMC) and myeloschisis leads to improved neurologic outcomes compared to postnatal repair, but the effects of modifications in closure techniques have not been extensively studied. Previous work has suggested that a watertight repair is requisite for improvement in hindbrain herniation (HBH) and to decrease postnatal hydrocephalus (HCP). Our institution adopted the myofascial closure technique for open fetal MMC repair in July 2019, which we hypothesized would result in decreased need for patch closure, improved HBH, and decreased rate of surgically-treated HCP.
• Vaughn, A. E., Lyttle, B. D., Tran, W., Derderian, S. C., Liechty, K. W., & Gien, J. (2023). Surgical Necrotizing Enterocolitis - Can We Predict the Need for Gastrostomy Tube Placement?. The Journal of surgical research, 295, 168-174.
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  Necrotizing enterocolitis (NEC) is a significant cause of morbidity and mortality among extremely premature infants. Approximately 50% of cases progress to surgery, frequently resulting in resection of necrotic bowel and ostomy creation. Premature neonates are at risk for bronchopulmonary dysplasia and feeding failure; surgery in these patients is higher risk. We evaluated the incidence of gastrostomy tube (GT) placement after ostomy reversal in surgical NEC to define a subset of patients who would benefit from concurrent ostomy reversal and GT placement.
• Vaughn, A., Lyttle, B., Gallagher, L., Gien, J., Derderian, S., & Liechty, K. (2023). Lung volume reduction surgery for ipsilateral emphysematous bullae after congenital diaphragmatic hernia repair. Journal of Pediatric Surgery Case Reports, 89(Issue). doi:10.1016/j.epsc.2022.102567
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  Congenital diaphragmatic hernia (CDH) is characterized by a diaphragmatic defect with herniation of abdominal organs into the thoracic cavity. Outcomes are largely dependent on the degree of pulmonary hypoplasia and pulmonary hypertension, with the most severe cases associated with approximately 50% mortality. Long term pulmonary complications are well known, however, development of lobar emphysema leading to hemodynamic instability is exceedingly rare. We report the case of a patient with severe left-sided CDH who underwent successful diaphragmatic hernia repair but subsequently developed emphysematous bullous disease of the left lung with hemodynamic compromise, requiring emergent lung volume reduction surgery.
• Wallbank, A. M., Vaughn, A. E., Niemiec, S., Bilodeaux, J., Lehmann, T., Knudsen, L., Kolanthai, E., Seal, S., Zgheib, C., Nozik, E., Liechty, K. W., & Smith, B. J. (2023). CNP-miR146a improves outcomes in a two-hit acute- and ventilator-induced lung injury model. Nanomedicine : nanotechnology, biology, and medicine, 50, 102679.
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  Acute respiratory distress syndrome (ARDS) has high mortality (~40 %) and requires the lifesaving intervention of mechanical ventilation. A variety of systemic inflammatory insults can progress to ARDS, and the inflamed and injured lung is susceptible to ventilator-induced lung injury (VILI). Strategies to mitigate the inflammatory response while restoring pulmonary function are limited, thus we sought to determine if treatment with CNP-miR146a, a conjugate of novel free radical scavenging cerium oxide nanoparticles (CNP) to the anti-inflammatory microRNA (miR)-146a, would protect murine lungs from acute lung injury (ALI) induced with intratracheal endotoxin and subsequent VILI. Lung injury severity and treatment efficacy were evaluated via lung mechanical function, relative gene expression of inflammatory biomarkers, and lung morphometry (stereology). CNP-miR146a reduced the severity of ALI and slowed the progression of VILI, evidenced by improvements in inflammatory biomarkers, atelectasis, gas volumes in the parenchymal airspaces, and the stiffness of the pulmonary system.
• Dewberry, L., Niemiec, S., Hilton, S., Louiselle, A., Singh, S., Sakthivel, T., Hu, J., Seal, S., Liechty, K., & Zgheib, C. (2022). Cerium oxide nanoparticle conjugation to microRNA-146a mechanism of correction for impaired diabetic wound healing. Nanomedicine: Nanotechnology, Biology, and Medicine, 40(Issue). doi:10.1016/j.nano.2021.102483
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  Diabetic wounds represent a significant healthcare burden and are characterized by impaired wound healing due to increased oxidative stress and persistent inflammation. We have shown that CNP-miR146a synthesized by the conjugation of cerium oxide nanoparticles (CNP) to microRNA (miR)-146a improves diabetic wound healing. CNP are divalent metal oxides that act as free radical scavenger, while miR146a inhibits the pro-inflammatory NFκB pathway, so CNP-miR146a has a synergistic role in modulating both oxidative stress and inflammation. In this study, we define the mechanism(s) by which CNP-miR146a improves diabetic wound healing by examining immunohistochemical and gene expression analysis of markers of inflammation, oxidative stress, fibrosis, and angiogenesis. We have found that intradermal injection of CNP-miR146a increases wound collagen, enhances angiogenesis, and lowers inflammation and oxidative stress, ultimately promoting faster closure of diabetic wounds.
• El Ghzaoui, C., Neal, C. J., Kolanthai, E., Fu, Y., Kumar, U., Hu, J., Zgheib, C., Liechty, K. W., & Seal, S. (2022). Assessing the bio-stability of microRNA-146a conjugated nanoparticles via electroanalysis. Nanoscale Advances, 5(Issue 1). doi:10.1039/d2na00600f
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  The number of diabetics is increasing worldwide and is associated with significant instances of clinical morbidity. Increased amounts of reactive oxygen species (ROS) and proinflammatory cytokines are associated with the pathogenesis of diabetic wounds and result in a significant delay in healing. Our previous studies have shown the ability of a cerium oxide nanoparticle (CNP) formulation conjugated with the anti-inflammatory microRNA miR146a (CNP-miR146a) to enhance the healing of diabetic wounds. The observed therapeutic activity exceeded the combined efficacies of the individual conjugate components (CNPs and miR146a alone), suggesting a synergistic effect. The current study evaluates whether the previously observed enhanced activity arises from increased agent delivery (simple nanocarrier activity) or is specific to the CNP-miR146a formulation (functional, bio-active nanomaterial). Comparison with miR146a conjugated gold (bioactive, metal) and silica (bioinert, oxide) nanoparticles (AuNPs and SiO2NPs) was performed in the presence of H2O2, as an analogue to the high levels of ROS present in the diabetic wound environment. Electrochemical studies, materials characterization, and chemical assays showed limited interaction of AuNP-miR146a with H2O2 and instability of SiO2NP-miR146a over time. In contrast, and in support of our prior results, CNP-miR146a displayed chemical stability and persistent ROS scavenging ability. Furthermore, it was determined that CNPs protect miR146a from oxidative damage under prolonged exposure to H2O2, whereas AuNPs and SiO2NPs were shown to be ineffective. Overall, these results reinforce the ability of CNPs to stabilize and protect miRNA while exhibiting robust antioxidant properties, suggesting that therapeutic activity observed in related earlier studies is not limited to a facile nanocarrier function.
• Eyerly-Webb, S., Ylvisaker, H., Beh, M., Lim, F., Liechty, K., Velasco, P., Dion, E., Snowise, S., Lillegard, J., & Feltis, B. (2022). Understanding the Care Journey and Needs of Advanced Fetal Care Center Patients. Permanente Journal, 26(2). doi:10.7812/tpp/21.189
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  INTRODUCTION: This study describes the parental perspective of the management and care experience of patients experiencing a pregnancy complicated by a fetal diagnosis to inform more supportive patient-centered care. METHODS: We conducted a prospective multicenter qualitative patient experience study at three metropolitan children’s hospitals’ advanced fetal care centers: the Cincinnati, Colorado, and Midwest Fetal Care Centers. Data were collected from pregnant patients who experienced the management of a pregnancy complicated by a fetal anomaly. Clinical journey data were obtained using qualitative research methods in post-birth semistructured interviews. We assembled a generalizable patient journey map to identify the general clinical encounters, and present common participant experiences from diagnosis to post-birth discharge. RESULTS: Fifteen families were interviewed; four experienced a loss (27%). Common experiences of trust, education, surrounding support, consistency, and abandonment emerged across all centers. Participant trust in their care team was gained through strong referrals, institutional reputation, and transparent outcomes. Unconditional care team support and continual reassurance was paramount to maintaining participant trust throughout their care journey. Participants appreciated both active and passive educational techniques at clinical touch points. A consistent point of contact assured participants. All families mentioned they felt close to their fetal care team; however, several mentioned that the post-birth transition of care created feelings of abandonment. CONCLUSIONS: When a family understands the clinical information and feels supported, they are empowered and confident in their ability to navigate their circumstances. Listening to the parental perspective is important to delivering sensitive fetal care.
• Fu, Y., Kolanthai, E., Neal, C., Kumar, U., Zgheib, C., Liechty, K., & Seal, S. (2022). Engineered Faceted Cerium Oxide Nanoparticles for Therapeutic miRNA Delivery. Nanomaterials, 12(24). doi:10.3390/nano12244389
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  In general, wound healing is a highly ordered process, with distinct phases of inflammation, proliferation, and remodeling. However, among diabetic patients, the progression through these phases is often impeded by increased level of oxidative stress and persistent inflammation. Our previous studies demonstrated that cerium oxide nanoparticles (CNPs) conjugated with therapeutic microRNA146a (miR146a) could effectively enhance wound healing by targeting the NFκB pathway, reducing oxidative stress and inflammation. In the present study, we consider the potential effects of nanomaterial surface-faceting and morphology on the efficacy of miRNA delivery. Compared with octahedral-CNPs and cubic-CNPs, rod-CNPs exhibited higher loading capacity. In addition, in comparing the influence of particle morphology on wound healing efficacy, several markers for bioactivity were evaluated and ascribed to the combined effects of the gene delivery and reactive oxygen species (ROS) scavenging properties. In the cellular treatment study, rod-CNP-miR146a displayed the greatest miR146a delivery into cells. However, the reduction of IL-6 was only observed in the octahedral-CNP-miR146a, suggesting that the efficacy of the miRNA delivery is a result of the combination of various factors. Overall, our results give enlightenments into the relative delivery efficiency of the CNPs with different morphology enhancing miRNA delivery efficacy.
• Gien, J., Kinsella, J., Behrendt, N., Zaretsky, M., Galan, H., & Liechty, K. (2022). Improved survival for infants with severe congenital diaphragmatic hernia. Journal of Perinatology, 42(9). doi:10.1038/s41372-022-01397-3
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  Background: Survival for severe (observed to expected lung-head ratio (O:E LHR) < 25%) congenital diaphragmatic hernia (CDH) remains a challenge (15–25%). Management strategies have focused on fetal endoscopic tracheal occlusion (FETO) and/or extracorporeal membrane oxygenation therapy (ECMO) utilization. Objective(s): Describe single center outcomes for infants with severe CDH. Study design: Observational study of 13 severe CDH infants managed with ECMO, a protocolized DR algorithm, and early repair on ECMO with an innovative perioperative anticoagulation strategy. Results: 13/140 (9.3%) infants met criteria and were managed with ECMO. 77% survived ECMO and 69% survived to discharge. 22% underwent tracheostomy. Median days on mechanical ventilation was 39 days (IQR 22:107.5) and length of stay 135 days (IQR 62.5:211.5). All infants received a gastrostomy tube (GT) and were discharged home on oxygen and pulmonary hypertension (PH) meds. Conclusion: Survival for infants with severe CDH can be optimized with early aggressive intervention and protocolized algorithms (149).
• Gien, J., Palmer, C., Liechty, K., & Kinsella, J. (2022). Early Abnormalities in Gas Exchange in Infants with Congenital Diaphragmatic Hernia. Journal of Pediatrics, 243(Issue). doi:10.1016/j.jpeds.2021.12.009
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  Objective: To determine how blood gas exchange is altered during the transition in the first hour of life in infants with congenital diaphragmatic hernia (CDH). Study design: This was a prospective observational cohort study evaluating arterial blood gas (ABG) samples and ventilator support in 34 infants with CDH in the first hour of life. Infants were stratified into mild, moderate, and severe CDH. The first ABG was compared with the umbilical cord ABGs and response to intervention evaluated on subsequent ABGs among infants with different CDH severities. Results: Infants were intubated at a median of 120 seconds (range 50-240 seconds) and ABGs obtained at a median of 6 minutes (IQR 4, 8 minutes), 16 minutes (IQR 13.5, 22.5 minutes), and 60 minutes (IQR 56, 64 minutes). Compared with the cord ABG, first ABG mean partial pressure of carbon dioxide (PaCO2) increased from 49.8 mm Hg to 82.1 mm Hg, mean base deficit decreased from −2.2 to −7.3, and mean pH from 7.298 to 7.060. With ventilator adjustments, second mean PaCO2 decreased to 76.7 mm Hg and third mean PaCO2 48.5 mm Hg. When stratified, with all CDH severities PaCO2 increased abruptly, remained elevated in moderate and severe CDH, and improved in all severities by 60 minutes after delivery. Conclusions: Gas exchange is markedly altered in the first hour of life in infants with CDH with abrupt onset of acidemia and a mixed respiratory and metabolic acidosis. Early implementation of adequate cardiopulmonary support may contribute to more timely stabilization of gas exchange.
• Louiselle, A., Niemiec, S., Azeltine, M., Mundra, L., French, B., Zgheib, C., & Liechty, K. (2022). Evaluation of skin care concerns and patient’s perception of the effect of NanoSilk Cream on facial skin. Journal of Cosmetic Dermatology, 21(3). doi:10.1111/jocd.14198
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  Background: Skin aging is an inevitable process with one of the key features of aging being dryness or flakiness of the skin. Previous in vivo and in vitro testing has highlighted that a silk-based product may be effective in improving moisture retention in skin. Methods: We evaluated the safety and efficacy of our silk-based product through a combination of objective- including scanning electron microscopy (SEM) and EpiDerm Skin Irritation tests - and subjective tests – including direct evaluation of patient’s own perception of their skin. Results: In alignment with previous studies, patients reported significant concerns about aging, wrinkling, or saggy skin. We found that our silk-based product was safe and effective in improving hydration and resilience of facial skin and a majority of participants stated they would continue to use this product, when commercially available. Conclusion: Our novel silk-based product, NanoSilk Cosmo, is safe for use on human facial skin and it improves skin resiliency and hydration.
• Niemiec, S. M., Hilton, S. A., Wallbank, A., Louiselle, A. E., Elajaili, H., Hu, J., Singh, S., Seal, S., Nozik, E., Smith, B., Zgheib, C., & Liechty, K. W. (2022). Lung function improves after delayed treatment with CNP-miR146a following acute lung injury. Nanomedicine: Nanotechnology, Biology, and Medicine, 40(Issue). doi:10.1016/j.nano.2021.102498
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  Acute respiratory distress syndrome (ARDS) is a highly morbid pulmonary disease characterized by hypoxic respiratory failure. Its pathogenesis is characterized by unrestrained oxidative stress and inflammation, with long-term sequelae of pulmonary fibrosis and diminished lung function. Unfortunately, prior therapeutic ARDS trials have failed and therapy is limited to supportive measures. Free radical scavenging cerium oxide nanoparticles (CNP) conjugated to the anti-inflammatory microRNA-146a (miR146a), termed CNP-miR146a, have been shown to prevent acute lung injury in a pre-clinical model. In this study, we evaluated the potential of delayed treatment with CNP-miR146a at three or seven days after injury to rescue the lung from acute injury. We found that intratracheal CNP-miR146a administered three days after injury lowers pulmonary leukocyte infiltration, reduce inflammation and oxidative stress, lower pro-fibrotic gene expression and collagen deposition in the lung, and ultimately improve pulmonary function.
• Niemiec, S., Louiselle, A., Phillips, R., Hilton, S., Derderian, S., Zaretsky, M., Galan, H., Behrendt, N., Kinsella, J., Liechty, K., & Gien, J. (2022). Reduction in blood product transfusion requirements with early on-ECMO repair of congenital diaphragmatic hernia. Annals of Pediatric Surgery, 18(1). doi:10.1186/s43159-021-00140-5
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  Background: For infants with severe congenital diaphragmatic hernia (CDH) stabilized with extracorporeal membrane oxygenation (ECMO), early repair on ECMO improves outcome; however when compared to operative repair after ECMO, repair on ECMO is associated with increase bleeding risk and need for blood product transfusions. Methods: A retrospective review of 54 patients with CDH placed on ECMO prior to CDH repair was performed. For the subset of patients repaired on ECMO, analysis comparing those repaired early (within 48 h of cannulation) and late (beyond 48 h) on ECMO was performed. Outcomes of interest included survival to discharge, days on ECMO, and postoperative blood product utilization. Results: When compared to those patients repaired prior to 48 h of ECMO initiation, 57.7% of patients survived versus 40.9% of late repair patients. For those repaired early, blood product utilization was significantly less. Early repair patients received a median of 72 mL/kg packed red blood cells (PRBC) and 75 mL/kg platelets compared to 151.9 mL/kg and 98.7 mL/kg, respectively (p < 0.05 respectively). There was no difference in median days on ECMO (p = 0.38). Conclusion: Our data supports prior reports of improved outcome with repair with 48 h of ECMO initiation and suggests early repair on ECMO is associated with less bleeding and decreased blood product requirement in the postoperative period.
• Phillips, R., Meier, M., Shahi, N., Niemiec, S., Ogle, S., Reppucci, M., Acker, S., Gien, J., Liechty, K., Meyers, M., & Marwan, A. (2022). Correction to: The novel fetal MRI O/E CLV versus O/E LHR in predicting prognosis in congenital diaphragmatic hernias: can we teach an old dog new tricks? (Pediatric Surgery International, (2021), 37, 11, (1499-1504), 10.1007/s00383-021-04936-9). Pediatric Surgery International, 38(2). doi:10.1007/s00383-021-05033-7
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  In the original publication, one of the co-author name Marina L. Reppucci was missed to include in the author group. The correct author group should read as follows: Ryan Phillips, Maxene Meier, Niti Shahi, Stephen Niemiec, Sarah Ogle, Marina L. Reppucci, Shannon Acker, Jason Gien, Kenneth W. Liechty, Mariana L. Meyers, Ahmed Marwan Dr Marina L. Reppucci’s affiliation is: Division of Pediatric Surgery, Children's Hospital Colorado, Aurora, CO, USA Department of Surgery, University of Colorado School of Medicine, Aurora, CO, USA
• Stager, M. A., Bardill, J., Raichart, A., Osmond, M., Niemiec, S., Zgheib, C., Seal, S., Liechty, K. W., & Krebs, M. D. (2022). Photopolymerized Zwitterionic Hydrogels with a Sustained Delivery of Cerium Oxide Nanoparticle-miR146a Conjugate Accelerate Diabetic Wound Healing. ACS Applied Bio Materials, 5(Issue 3). doi:10.1021/acsabm.1c01155
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  In the United States, $87 billion per year is spent on the care of diabetic ulcers alone. Although the pathophysiology of diabetic wound healing is multifaceted, high systemic levels of inflammation and increased reactive oxygen species are often implicated in the wound healing impairment. Zwitterionic materials have been demonstrated to reduce inflammation and increase extracellular matrix deposition in wound beds, and here, we demonstrate a fabrication method for photopolymerized zwitterionic hydrogels that also enables sustained drug delivery over time. A therapeutic molecule of interest that is examined in this work is cerium oxide nanoparticle tagged with microRNA-146a (CNP-miR146a) to combat both oxidative stress and inflammation. The hydrogels are composed of zwitterionic and nonzwitterionic monomers, and the hydrogel formation occurs in the absence of a crosslinker. The hydrogels exhibit a wide range of stiffness and mechanical properties depending on their monomer content. Additionally, these hydrogels exhibit sustained release of nanoparticles and proteins. Finally, when employed in an in vivo diabetic mouse wound healing model, the zwitterionic hydrogels alone and laden with the CNP-miR146a conjugate significantly improved the rate of diabetic wound healing. Overall, these materials have excellent potential to be used as a topical treatment for chronic diabetic wounds.
• Xu, J., Hu, J., Idlett-Ali, S., Zhang, L., Caples, K., Peddibhotla, S., Reeves, M., Zgheib, C., Malany, S., & Liechty, K. (2022). Discovery of Small Molecule Activators of Chemokine Receptor CXCR4 That Improve Diabetic Wound Healing. International Journal of Molecular Sciences, 23(4). doi:10.3390/ijms23042196
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  Diabetes produces a chronic inflammatory state that contributes to the development of vascular disease and impaired wound healing. Despite the known individual and societal impacts of diabetic ulcers, there are limited therapies effective at improving healing. Stromal cell-derived factor 1α (SDF-1α) is a CXC chemokine that functions via activation of the CXC chemokine receptor type 4 (CXCR4) receptor to recruit hematopoietic cells to locations of tissue injury and promote tissue repair. The expression of SDF-1α is reduced in diabetic wounds, suggesting a potential contribution to wound healing impairment and presenting the CXCR4 receptor as a target for therapeutic investigations. We developed a high-throughput β-arrestin recruitment assay and conducted structure–activity relationship (SAR) studies to screen compounds for utility as CXCR4 agonists. We identified CXCR4 agonist UCUF-728 from our studies and further validated its activity in vitro in diabetic fibroblasts. UCUF-728 reduced overexpression of miRNA-15b and miRNA-29a, negative regulators of angiogenesis and type I collagen production, respectively, in diabetic fibroblasts. In vivo, UCUF-728 reduced the wound closure time by 36% and increased the evidence of angiogenesis in diabetic mice. Together, this work demonstrates the clinical potential of small molecule CXCR4 agonists as novel therapies for pathologic wound healing in diabetes.
• Hodges, M., Zgheib, C., & Liechty, K. (2021). A Large Mammalian Model of Myocardial Regeneration after Myocardial Infarction in Fetal Sheep. Adv Wound Care (New Rochelle), 10(4). doi:10.1089/wound.2018.0894
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  Objective: Ischemic heart disease accounts for over 20% of all deaths worldwide. As the global population faces a rising burden of chronic diseases, such as hypertension, hyperlipidemia, and diabetes, the prevalence of heart failure due to ischemic heart disease is estimated to increase. We sought to develop a model that may more accurately identify therapeutic targets to mitigate the development of heart failure following myocardial infarction (MI). Approach: Having utilized fetal large mammalian models of scarless wound healing, we proposed a fetal ovine model of myocardial regeneration after MI. Results: Use of this model has identified critical pathways in the mammalian response to MI, which are differentially activated in the regenerative, fetal mammalian response to MI when compared to the reparative, scar-forming, adult mammalian response to MI. Innovation: While the foundation of myocardial regeneration research has been built on zebrafish and rodent models, effective therapies derived from these disease models have been lacking; therefore, we sought to develop a more representative ovine model of myocardial regeneration after MI to improve the identification of therapeutic targets designed to mitigate the development of heart failure following MI. Conclusions: To develop therapies aimed at mitigating this rising burden of disease, it is critical that the animal models we utilize closely reflect the physiology and pathology we observe in human disease. We encourage use of this ovine large mammalian model to facilitate identification of therapies designed to mitigate the growing burden of heart failure.
• Lyttle, B., Liechty, K., Corkum, K., Galan, H., Behrendt, N., Zaretsky, M., Bruny, J., & Derderian, S. (2021). In-utero gastric perforation from combined duodenal and esophageal atresia without consistent polyhydramnios. Journal of Surgical Case Reports, 2021(12). doi:10.1093/jscr/rjab551
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  We present a case in which prenatal imaging at 21-weeks' gestation suggested duodenal atresia with a double-bubble sign and enlarged stomach. Fetal magnetic resonance imaging findings demonstrated dilation of the stomach and proximal duodenum favoring duodenal atresia but no indications of esophageal atresia. Subsequent prenatal imaging demonstrated interval spontaneous decompression of the stomach without the development of polyhydramnios, obscuring the diagnosis. Postnatally, initial abdominal radiography showed a gasless abdomen, and an oral gastric tube could not pass the mid-esophagus, raising concern for pure esophageal atresia. Intraoperative findings were consistent with duodenal atresia, pure esophageal atresia and a gastric perforation due to a closed obstruction. In this case report, we review the prenatal diagnostic challenges and the limited literature pertaining to this unique pathology.
• Niemiec, S., Hilton, S., Wallbank, A., Azeltine, M., Louiselle, A., Elajaili, H., Allawzi, A., Xu, J., Mattson, C., Dewberry, L., Hu, J., Singh, S., Sakthivel, T., Sea, S., Nozik-Grayck, E., Smith, B., Zgheib, C., & Liechty, K. (2021). Cerium oxide nanoparticle delivery of microRNA-146a for local treatment of acute lung injury. Nanomedicine: Nanotechnology, Biology, and Medicine, 34(Issue). doi:10.1016/j.nano.2021.102388
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  Acute respiratory distress syndrome (ARDS) is a devastating pulmonary disease with significant in-hospital mortality and is the leading cause of death in COVID-19 patients. Excessive leukocyte recruitment, unregulated inflammation, and resultant fibrosis contribute to poor ARDS outcomes. Nanoparticle technology with cerium oxide nanoparticles (CNP) offers a mechanism by which unstable therapeutics such as the anti-inflammatory microRNA-146a can be locally delivered to the injured lung without systemic uptake. In this study, we evaluated the potential of the radical scavenging CNP conjugated to microRNA-146a (termed CNP-miR146a) in preventing acute lung injury (ALI) following exposure to bleomycin. We have found that intratracheal delivery of CNP-miR146a increases pulmonary levels of miR146a without systemic increases, and prevents ALI by altering leukocyte recruitment, reducing inflammation and oxidative stress, and decreasing collagen deposition, ultimately improving pulmonary biomechanics.
• Phillips, R., Shahi, N., Meier, M., Niemiec, S., Ogle, S., Acker, S., Gien, J., Liechty, K., Meyers, M., & Marwan, A. (2021). The novel fetal MRI O/E CLV versus O/E LHR in predicting prognosis in congenital diaphragmatic hernias: can we teach an old dog new tricks?. Pediatric Surgery International, 37(11). doi:10.1007/s00383-021-04936-9
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  Purpose: In congenital diaphragmatic hernia (CDH), ultrasound (U/S) measurements of the contralateral lung commonly provide the observed-to-expected lung-to-head ratio (O/E LHR) and are used to determine the severity of pulmonary hypoplasia. Fetal magnetic resonance imaging (MRI) measurement of the observed-to-expected total lung volume (O/E TLV) has been used as an adjunct to O/E LHR in predicting outcomes. Since O/E LHR only measures the contralateral lung, we sought to investigate if MRI measurements of the contralateral lung volume (O/E CLV) can accurately predict outcomes in CDH. We hypothesize that O/E CLV is a better predictor of CDH outcomes than O/E LHR. Methods: We identified all infants with a prenatal diagnosis of CDH at our fetal center who had both MRI and U/S measurements. Using lung volume ratios of right–left 55:45, we calculated O/E CLV from O/E TLV. We used receiver-operating characteristic (ROC) curves to calculate the area under the curve (AUC) to compare the predictive accuracy of O/E CLV to O/E LHR for ECMO support, as well as survival to both discharge and 1 year. Results: Seventy-four patients had complete prenatal imaging with 39% requiring ECMO support. The median O/E CLV was 48.0% and the median O/E LHR was 42.3%. O/E CLV was a better predictor of the need for ECMO support (AUC 0.81 vs. 0.74). O/E CLV was a better predictor of survival to discharge (AUC 0.84 vs. 0.64) and 1-year survival (AUC 0.83 vs. 0.63) than O/E LHR. Conclusion: O/E LHR is a well-validated standard for predicting outcomes and guiding prenatal counseling in CDH. We provide evidence that fetal MRI measurements of the contralateral lung volume corrected for gestational age were more accurate in predicting the need for ECMO and survival. Future prospective studies validating O/E CLV regarding outcomes and ECMO utilization are warranted. Level of evidence: Level III, retrospective comparative study.
• Porter, A., Behrendt, N., Zaretsky, M., Liechty, K., Wood, C., Chow, F., & Galan, H. (2021). Continuous local bupivacaine wound infusion reduces oral opioid use for acute postoperative pain control following myelomeningocele repair. American Journal of Obstetrics and Gynecology MFM, 3(2). doi:10.1016/j.ajogmf.2020.100296
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  Background: For pregnancies complicated by fetal myelomeningocele who meet the established criteria, prenatal closure is a viable management option. Prenatal closure is an open procedure, with some techniques requiring greater dissection of maternal tissue than cesarean delivery; pain control is an important postoperative goal. Given the rising rates of opioid dependence and concerns regarding the fetal and neonatal effects of opioid use, our practice has turned to nonopioid pain management techniques. Objective: This study aimed to compare postoperative opioid use and pain scores in women undergoing open fetal myelomeningocele repair with and without continuous local bupivacaine wound infusion. Study Design: This was a retrospective, single-center chart review of all consecutive patients who underwent open myelomeningocele repair from March 2013 to December 2019. Women were enrolled at the time of referral and locally followed for 2 weeks postoperatively. The control group received patient-controlled epidural analgesia for 48 hours with acetaminophen and oral and intravenous opioids as needed. The treatment group received patient-controlled epidural analgesia for 24 hours with acetaminophen, oral and intravenous opioids, and continuous local bupivacaine infusion. Pain scores, medication use, and postoperative milestones and complications through discharge were abstracted from the chart and compared. Results: Of 72 subjects, 51 were in the control group and 21 in the treatment group. Total opioid use, including intravenous doses (165 vs 52.5 mg; P=.001) and daily average oral opioid use (30 vs 10.5 mg; P=.002) were lower in the treatment group. In addition, 24% of women in the treatment group used no opioid postoperatively, compared with 4% in the control group. There was no difference in postoperative day 1 to 4 pain scores, antiemetic use, or bowel function; the treatment group was discharged significantly earlier. Conclusion: Postoperative opioid use was reduced in women who received continuous local wound infusion of bupivacaine for incisional pain control after prenatal myelomeningocele repair. Pain control is paramount following open myelomeningocele repair; local bupivacaine wound infusion is an important adjunct to reduce opioid use postoperatively.
• Zhang, L., Hu, J., Meshkat, B., Liechty, K., & Xu, J. (2021). Lncrna malat1 modulates tgf-β1-induced emt in keratinocyte. International Journal of Molecular Sciences, 22(21). doi:10.3390/ijms222111816
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  One of the major complications in diabetes is impaired wound healing. Unfortunately, effective therapies are currently lacking. Epithelial to mesenchymal transition (EMT) is a critical process involved in cutaneous wound healing. In response to injury, EMT is required to activate and mobilize stationary keratinocytes in the skin toward the wound bed, which allows for re-epithelialization. This process is stalled in diabetic wounds. In this study, we investigate the role of long non-coding RNA (lncRNA), MALAT1, in transforming growth factor beta 1(TGF-β1)-induced EMT of human keratinocyte (HaCaT) cells. Initially, we detected MALAT1 and TGF-β1 expression in non-diabetic and diabetic wounds and found that these expression are significantly up-regulated in diabetic wounds. Then, HaCaT cells were cultured and exposed to TGF-β1. The EMT of HaCaT cells were confirmed by the increased expression of CDH2, KRT10, and ACTA2, in addition to the down-regulation of CDH1. Knockdown of MALAT1 was achieved by transfecting a small interfering RNA (SiRNA). MALAT1 silencing attenuates TGFβ1-induced EMT. Mechanistically, MALAT1 is involved in TGF-β1 mediated EMT through significantly induced ZEB1 expression, a critical transcription factor for EMT. In summary, lncRNA MALAT1 is involved in TGFβ1-induced EMT of human HaCaT cells and provides new understanding for the pathogenesis of diabetic wounds.
• Dewberry, L., Hilton, S., Vuille-dit-Bille, R., & Liechty, K. (2020). Is Tapering Enteroplasty an Alternative to Resection of Dilated Bowel in Small Intestinal Atresia?. Journal of Surgical Research, 246(Issue). doi:10.1016/j.jss.2019.08.014
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  Background: Intestinal atresia is a congenital defect resulting in intestinal discontinuity and can be associated with significant morbidity related to intestinal failure. The bowel proximal to the atresia is often significantly dilated and dysfunctional. The treatment approaches of this dilated bowel include resection with primary anastomosis versus tapering enteroplasty with preservation of bowel length. The purpose of this study was to compare these two approaches in regard to bowel function as characterized by the time to full enteral feeding. Methods: A retrospective review was performed of intestinal atresia repair performed at a tertiary referral pediatric hospital from 2007 to 2017. Length of stay, time to full enteral feeds, and complications were assessed in patients who underwent repair with tapering enteroplasty (n = 8) and compared with those who underwent resection and anastomosis (n = 39). Results: The median age at surgery, gender distribution, weeks gestational age (WGA), location of the atresia, and comorbidities were similar between the two groups. Overall, there was no statistically significant difference in length of stay and time to full enteral feeds between groups. Three of eight (38%) patients in the tapered group and five of 39 patients (13%; P = 0.12) in the nontapered group underwent further surgical exploration because of bowel dysmotility. Factors associated with longer length of hospital stay were abdominal reoperation and WGA, and factors associated with longer time to full enteral feeds were WGA, abdominal reoperation, and gastroschisis. Conclusions: Tapering enteroplasty at initial operation for intestinal atresias preserves bowel length and has statistically equivalent outcomes to resection and anastomosis in regard to the length of stay and time to full enteral feeds.
• Dewberry, L., Hilton, S., Vuille-dit-Bille, R., & Liechty, K. (2020). Tapering duodenoplasty: a beneficial adjunct in the treatment of congenital duodenal obstruction. Journal of International Medical Research, 48(1). doi:10.1177/0300060519862109
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  Objective: Congenital duodenal obstruction is typically treated by duodenoduodenostomy. Tapering of the dilated segment has been indicated to reduce duodenal dysmotility. The purpose of this study was to review the outcomes between these two approaches. Methods: We retrospectively reviewed cases of duodenal obstruction repair performed at a quaternary care referral pediatric hospital from 2007 to 2017. The length of stay, time to full enteral feeding, and complications were compared between patients who underwent duodenoduodenostomy with and without tapering duodenoplasty (n=4 and n=35, respectively). Results: Both groups had similar times to initial enteral feeding (7 days) and full enteral feeding (14 vs. 15 days). Among the 35 patients who underwent duodenoduodenostomy alone, 6 (17%) required a return to the operating room; in contrast, no patients who underwent tapering required a return to the operating room. Of those who returned to the operating room, two underwent tapering at that time because of duodenal dilation and feeding intolerance. Conclusions: Although limited by the small sample size, this study suggests that patients undergoing tapering duodenoplasty may have a slightly shorter time to full enteral feeding and a lower rate of complications than patients undergoing duodenoduodenostomy alone.
• Dewberry, L., Hilton, S., Zaretsky, M., Behrendt, N., Galan, H., Marwan, A., & Liechty, K. (2020). Examination of Prenatal Sonographic Findings: Intra-Abdominal Bowel Dilation Predicts Poor Gastroschisis Outcomes. Fetal Diagnosis and Therapy, 47(3). doi:10.1159/000501592
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  Background: Gastroschisis is an anterior abdominal wall defect with variable outcomes. There are conflicting data regarding the prognostic value of sonographic findings. Objectives: The aim of this study was to identify prenatal ultrasonographic features associated with poor neonatal outcomes. Method: A retrospective review of 55 patients with gastroschisis from 2007 to 2017 was completed. Ultrasounds were reviewed for extra-abdominal intestinal diameter (EAID) and intra-abdominal intestinal diameter (IAID), echogenicity, visceral content within the herniation, amniotic fluid index, defect size, and abdominal circumference (AC). Ultrasound variables were correlated with full enteral feeding and the diagnosis of a complex gastroschisis. Results: Bivariate analysis demonstrated an increased time to full enteral feeds with increasing number of surgeries, EAID, and IAID. Additionally, there was a significant relationship between IAID and AC percentile with the diagnosis of complex gastroschisis. On multivariate analysis, only IAID was significant and increasing diameter had a 2.82 (95% CI 1.02-7.78) higher odds of a longer time to full enteral feeds and a 1.2 (95% CI 1.05-1.36) greater odds of the diagnosis of a complex gastroschisis. Conclusions: Based on these findings, IAID is associated with a longer time to full enteral feeding and the diagnosis of complex gastroschisis.
• Dewberry, L., Kalia, N., Vazquez, J., Hilton, S., Zaretsky, M., Behrendt, N., Galan, H., Marwan, A., & Liechty, K. (2020). Determining maternal risk factors for gastroschisis using colorado's birth registry database. Journal of Pediatric Surgery, 55(6). doi:10.1016/j.jpedsurg.2020.02.030
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  Aim of Study: Gastroschisis is a congenital abdominal wall defect which results in herniation of abdominal contents. The objective of this study was to determine the maternal risk factors for gastroschisis in Colorado. Methods: A case–control study was performed using the Birth Registry database from 2007 to 2016. The outcome was gastroschisis, and the main variable was maternal age which was divided into < 21, 21–30, and > 30 years of age. Descriptive analysis, bivariate analysis, and logistic regression was performed. Results: There were 236 cases of gastroschisis compared to 944 controls. Maternal age did vary significantly between groups (23.4 ± 5 years (cases) vs. 28.7 ± 5.9 years (controls); p < 0.0001). Unadjusted analysis demonstrated that those with young maternal age (< 21 years of age) had a 14.14 (95% CI 8.44–23.67) higher odds of gastroschisis compared to those > 30 years of age. Independent risk factors for gastroschisis were exposure to prenatal and first trimester cigarettes, prenatal and first trimester alcohol, and chlamydia infection. The odds (4.41, 95% CI 1.36–14.26) of gastroschisis were highest in those with first trimester cigarette exposure and young maternal age (p = 0.03). Conclusions: Young maternal age, cigarette exposure, alcohol exposure, and chlamydia infection increase the odds of gastroschisis. The interaction between young maternal age and first trimester cigarette exposure significantly increases the odds of gastroschisis. Type of Study: Prognosis Study. Level of Evidence: Level III.
• Dewberry, L., Trecartin, A., Galambos, C., Hilton, S., Dannull, K., Zaretsky, M., Behrendt, N., Galan, H., Marwan, A., & Liechty, K. (2020). A congenital cystic pulmonary airway malformation occurring together with both an extralobar pulmonary sequestration and an esophageal duplication cyst. Clin Case Rep., 8(1). doi:10.1002/ccr3.2455
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  A foregut duplication cyst occurring together with both a congenital cystic pulmonary airway malformation and extralobar pulmonary sequestration is an unusual combination. Prenatal ultrasound, MRI, and postnatal CT are helpful for operative planning. Surgical resection is the definitive management for all three anomalies.
• Guglielmetti, L., Estrada, A., Phillips, R., Staerkle, R., Gien, J., Kinsella, J., Liechty, K., Marwan, A., & Vuille-Dit-Bille, R. (2020). Congenital diaphragmatic hernias: Severe defect grade predicts the need for fundoplication. Medicine (United States), 99(49). doi:10.1097/md.0000000000023383
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  Over one-third of infants with congenital diaphragmatic hernia (CDH) eventually require a Nissen fundoplication (NF). We examined pre- and intraoperative predictors for need of a NF in children undergoing CDH repair to elucidate, which patients will need a later NF.A retrospective analysis of all consecutive patients undergoing CDH repair at our institution from 2008 to 2018 was performed. Patients who underwent a NF were compared to those who did not (noNissen). Logistic regression analysis was performed to find independent predictors for NF in patients undergoing CDH repair. Severe Defect Grade was defined as defect >50% of the hemidiaphragm and intrathoracic liver.One hundred twenty-six patients were included, 42 (33%) underwent NF at a median of 61 days after CDH repair. Intrathoracic liver was more frequent in the NF (71%) versus noNissen (45%) group (P = .008). Absence of >50% of the hemidiaphragm was more frequent in the NF group (76% vs 31%, P < .001). Severe Defect Grade emerged as independent predictor for NF (odds ratio 7, 95% confidence interval 3-16, P < .001).Severe Defect Grade emerged as independent predictor for NF after CDH repair.
• Hu, J., Zhang, L., Liechty, C., Zgheib, C., Hodges, M., Liechty, K., & Xu, J. (2020). Long Noncoding RNA GAS5 Regulates Macrophage Polarization and Diabetic Wound Healing. Journal of Investigative Dermatology, 140(8). doi:10.1016/j.jid.2019.12.030
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  A central feature of diabetic (Db) wounds is the persistence of chronic inflammation, which is partly due to the prolonged presence of proinflammatory (M1) macrophages. Using in vivo and in vitro analyses, we have tested the hypothesis that long noncoding RNA GAS5 is dysregulated in Db wounds. We have assessed the contribution of GAS5 to the M1 macrophage phenotype, as well as the functional consequences of knocking down its expression. We found that expression of GAS5 is increased significantly in Db wounds and in cells isolated from Db wounds. Hyperglycemia induced GAS5 expression in macrophages in vitro. Overexpression of GAS5 in vitro promoted macrophage polarization toward an M1 phenotype by upregulating signal transducer and activator of transcription 1. Of most significance in our judgment, GAS5 loss-of-function enhanced Db wound healing. These data indicate that the relative level of long noncoding RNA GAS5 in wounds plays a key role in the wound healing response. Reductions in the levels of GAS5 in wounds appeared to enhance healing by promoting transition of M1 macrophages to M2 macrophages. Thus, our results suggest that targeting long noncoding RNA GAS5 may provide a therapeutic intervention for correcting impaired Db wound healing.
• Leopold, D., Phillips, R., Shahi, N., Gien, J., Marwan, A., Kinsella, J., Mulligan, J., Liechty, K., & Moulton, S. (2020). Low postnatal CRI values are associated with the need for ECMO in newborns with CDH. Journal of Pediatric Surgery, 55(1). doi:10.1016/j.jpedsurg.2019.09.050
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  Introduction: Accurate, real-time technology is needed to predict which newborns with congenital diaphragmatic hernia (CDH) will require ECMO. The Compensatory Reserve Index (CRI) is a noninvasive monitoring technology that continuously trends an individual's capacity to compensate from normovolemia (CRI = 1) to decompensation (CRI = 0). We hypothesized that postnatal CRI values would be lower in CDH newborns that required ECMO than those who did not require ECMO. Methods: Newborns with a CDH were prospectively monitored with a CipherOx® CRI M1 device. We compared CRI values from delivery to ECMO (ECMO group) versus delivery to clinical stabilization (non-ECMO group). Results: Postnatal CRI values were available from 26 newborns. Eight underwent ECMO within 33 h of delivery, and median CRI prior to ECMO was 0.068 (IQR: 0.057, 0.078). Eighteen did not require ECMO. Median CRI from birth to 48 h was 0.112 (IQR: 0.082, 0.15). CRI values were significantly lower in newborns that required ECMO versus those who did not (p = 0.0035). Postnatal CRI had the highest AUC (0.85) compared to other prenatal prognostic measures. Conclusion: Humans from newborns to adults share elemental features of the pulsatile waveform that are associated with progression to decompensation. CRI may be helpful when deciding when to initiate ECMO. Level of evidence: Level III. Type of study: Diagnostic test.
• Liechty, C., Hu, J., Zhang, L., Liechty, K., & Xu, J. (2020). Role of microRNA-21 and its underlying mechanisms in inflammatory responses in diabetic wounds. International Journal of Molecular Sciences, 21(9). doi:10.3390/ijms21093328
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  A central feature of diabetic wounds is the persistence of chronic inflammation, which is partly due to the prolonged presence of pro-inflammatory (M1) macrophages in diabetic wounds. Persistence of the M1 macrophage phenotype and failure to transition to the regenerative or pro-remodeling (M2) macrophage phenotype plays an indispensable role in diabetic wound impairment; however, the mechanism underlying this relationship remains unclear. Recently, microRNAs have been shown to provide an additional layer of regulation of gene expression. In particular, microRNA-21 (miR-21) is essential for an inflammatory immune response. We hypothesize that miR-21 plays a role in regulating inflammation by promoting M1 macrophage polarization and the production of reactive oxygen species (ROS). To test our hypothesis, we employed an in vivo mouse skin wound model in conjunction with an in vitro mouse model to assess miR-21 expression and macrophage polarization. First, we found that miR-21 exhibits a distinct expression pattern in each phase of healing in diabetic wounds. MiR-21 abundance was higher during early and late phases of wound repair in diabetic wounds, while it was significantly lower in the middle phase of wounding (at days 3 and 7 following wounding). In macrophage cells, M1 polarized macrophages exhibited an upregulation of miR-21, as well as the M1 and pro-inflammatory markers IL-1b, TNFa, iNos, IL-6, and IL-8. Overexpression of miR-21 in macrophage cells resulted in an upregulation of miR-21 and also increased expression of the M1 markers IL-1b, TNFa, iNos, and IL-6. Furthermore, hyperglycemia induced NOX2 expression and ROS production through the HG/miR-21/PI3K/NOX2/ROS signaling cascade. These findings provide evidence that miR-21 is involved in the regulation of inflammation. Dysregulation of miR-21 may explain the abnormal inflammation and persistent M1 macrophage polarization seen in diabetic wounds.
• Niemiec, S., Louiselle, A., Hilton, S., Dewberry, L., Zhang, L., Azeltine, M., Xu, J., Singh, S., Sakthivel, T., Seal, S., Liechty, K., & Zgheib, C. (2020). Nanosilk Increases the Strength of Diabetic Skin and Delivers CNP-miR146a to Improve Wound Healing. Frontiers in Immunology, 11(Issue). doi:10.3389/fimmu.2020.590285
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  Diabetes mellitus is a metabolic disorder associated with properties and an increased risk of chronic wounds due to sustained pro-inflammatory response. We have previously of radical scavenging cerium oxide nanoparticles (CNP) conjugated to the anti-inflammatory microRNA (miR)-146a, termed CNP-miR146a, improves diabetic wound healing by synergistically lowering oxidative stress and inflammation, and we sought to evaluate this treatment in a topical application. Silk fibroin is a biocompatible polymer that can be fabricated into nanostructures, termed nanosilk. Nanosilk is characterized by a high strength-to-density ratio and an ability to exhibit strain hardening. We therefore hypothesized that nanosilk would strengthen the biomechanical properties of diabetic skin and that nanosilk solution could effectively deliver CNP-miR146a to improve diabetic wound healing. The ability of nanosilk to deliver CNP-miR146a to murine diabetic wounds and improve healing was assessed by the rate of wound closure and inflammatory gene expression, as well as histologic analysis. The effect of nanosilk on the properties of human diabetic skin was evaluated by testing the biomechanical properties following topical application of a 7% nanosilk solution. Diabetic murine wounds treated with topical nanosilk and CNP-miR146a healed by day 14.5 compared to day 16.8 in controls (p = 0.0321). Wounds treated with CNP-miR146a had higher collagen levels than controls (p = 0.0126) with higher pro-fibrotic gene expression of TGFβ-1 (p = 0.0092), Col3α1 (p = 0.0369), and Col1α2 (p = 0.0454). Treatment with CNP-miR146a lowered pro-inflammatory gene expression of IL-6 (p = 0.0488) and IL-8 (p = 0.0009). Treatment of human diabetic skin with 7% nanosilk solution resulted in significant improvement in maximum load and modulus (p < 0.05). Nanosilk solution is able to strengthen the biomechanical properties of diabetic skin and can successfully deliver CNP-miR146a to improve diabetic wound healing through inhibition of pro-inflammatory gene signaling and promotion of pro-fibrotic processes.
• Phillips, R., Shahi, N., Leopold, D., Levek, C., Shirek, G., Hilton, S., Hyslop, R., Gien, J., Kinsella, J., Buckvold, S., Liechty, K., Kim, J., & Marwan, A. (2020). Thromboelastography-guided management of coagulopathy in neonates with congenital diaphragmatic hernia supported by extracorporeal membrane oxygenation. Pediatric Surgery International, 36(9). doi:10.1007/s00383-020-04694-0
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  Purpose: Congenital diaphragmatic hernia (CDH) can cause severe hemodynamic deterioration requiring support with extracorporeal membrane oxygenation (ECMO). ECMO is associated with hemorrhagic and thromboembolic complications. In 2015, we standardized anti-coagulation management on ECMO, incorporating thromboelastography (TEG) as an adjunct to manage hemostasis of CDH patients. The purpose of this study is to evaluate our blood product utilization, choice of blood product use in response to abnormal TEG parameters, and the associated effect on bleeding and thrombotic complications. Methods: We retrospectively reviewed all CDH neonates supported by ECMO between 2008 and 2018. Blood product administration, TEG data, and hemorrhagic and thrombotic complications data were collected. We divided subjects into two groups pre-2015 and post-2015. Results: After 2015, platelet transfusion was administered for a low maximum amplitude (MA) more frequently (77% compared to 65%, p = 0.0007). Cryoprecipitate was administered less frequently for a low alpha-angle (28% compared to 41%, p = 0.0016). There was no difference in fresh frozen plasma use over time. After standardizing the use of TEG, we observed a significant reduction in hemothoraces (18% compared to 54%, p = 0.026). Conclusion: Institutional standardization of anti-coagulation management of CDH neonates on ECMO, including the use of goal-directed TEG monitoring may lead to improved blood product utilization and a decrease in bleeding complications in neonates with CDH supported by ECMO. Level of evidence/type of study: Level III, Retrospective comparative study
• Sener, G., Hilton, S., Osmond, M., Zgheib, C., Newsom, J., Dewberry, L., Singh, S., Sakthivel, T., Seal, S., Liechty, K., & Krebs, M. (2020). Injectable, self-healable zwitterionic cryogels with sustained microRNA - cerium oxide nanoparticle release promote accelerated wound healing. Acta Biomaterialia, 101(Issue). doi:10.1016/j.actbio.2019.11.014
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  Diabetics are prone to chronic wounds that have slower healing, and methods of accelerating the wound closure and to ensure protection from infections are critically needed. MicroRNA-146a gets dysregulated in diabetic wounds and injection of this microRNA combined with reactive oxygen species-scavenging cerium oxide nanoparticles (CNPs) can reduce inflammation and improve wound healing; however, a better delivery method than intradermal injections is needed. Here we demonstrate a biomaterial system of zwitterionic cryogels (gels formed below freezing temperatures) laden with CNP-miR146a that are topically applicable, injectable, self-healable, and provide sustained release of the therapeutic molecules. These cryogels are comprised of CBMA or SBMA and HEMA, and do not contain chemical crosslinkers. Properties of the gels can be manipulated by changing monomer type and ratio. These materials have demonstrated efficacy and viability in vivo with a diabetic mouse wound healing model. Overall, these materials have a high potential for application in wound treatments due to their ease of production, antifouling characteristics, durability, topical application, and sustained release mechanics. Statement of significance: This work presents the development of zwitterionic cryogels with unique physical properties including injectability and self-healing, that also offer highly sustained release of nanoparticles over time to improve wound healing in a diabetic mouse model. The nanoparticles are made of cerium oxide, which is known to scavenge reactive oxygen species and reduce oxidative stress, and these particles have been further tagged with a microRNA146a that has been shown to reduce inflammation. Zwitterionic materials are known for their superior antifouling properties and good biocompatibility and ability to incorporate bioactive factors. Given these properties, the use of these materials as wound healing dressings would be exciting, yet to date it has been difficult to prolong the release of bioactive factors from them due to their hydrophilicity. Previously we developed zwitterionic cyrogels with very sustained protein release over time, but those materials were quite brittle and difficult to handle. Here, we demonstrate for the first time that by removing the crosslinker molecule from our reaction and polymerizing gels under cryo-conditions, we are able to form zwitterionic cryogels that are injectable, self-healing, and with sustained release profiles. The sustained release of miRNA146a-tagged cerium oxide nanoparticles from these gels is demonstrated to speed up diabetic wound healing time and significantly reduce inflammation.
• Singh, S., Cortes, G., Kumar, U., Sakthivel, T. S., Niemiec, S. M., Louiselle, A. E., Azeltine-Bannerman, M., Zgheib, C., Liechty, K. W., & Seal, S. (2020). Silk fibroin nanofibrous mats for visible sensing of oxidative stress in cutaneous wounds. Biomaterials Science, 8(Issue 21). doi:10.1039/d0bm01325k
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  Wound healing is of major clinical concern and is constantly being explored for early restoration and enhanced recovery. While the etiology of the wound healing is multifactorial, high inflammation and increased oxidative stress which results in chronic inflammation, endothelial dysfunction and collagen degradation, delay the overall healing process. Thus, visual sensing of the oxidative stress would be highly informative in the successful implementation of wound healing therapies based on specific requirements. In this study, electrospinning was used to fabricate silk fibroin nanofibrous mats infused with Amplex red capable of detecting hydrogen peroxide, a reactive oxygen molecule. These mats produced a visible change in color with the limit of detection at 1 μM H2O2 concentration. In vivo studies carried out in diabetic mice with impaired wounds also displayed a visible change in color of the mats infused with Amplex red within 24 hours. These electrospun silk fibroin nanofibrous Amplex infused mats has the potential to enable a futuristic platform where decisions can be made for enhanced wound healing therapy.
• Vuille-dit-Bille, R., Liechty, K., Verrey, F., & Guglielmetti, L. (2020). SARS-CoV-2 receptor ACE2 gene expression in small intestine correlates with age. Amino Acids, 52(6-7). doi:10.1007/s00726-020-02870-z
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  Gastrointestinal symptoms are common in COVID-19 patients, especially in younger patients. Our hypothesis was that intestinal SARS-CoV-2 receptor ACE2 expression depends on patients’ age. We examined duodenal biopsies from 43 healthy human adults. ACE2 gene expression was directly correlated with age (Spearman’s r = 0.317, p = 0.039). With each year, duodenal ACE2 expression increased by 0.083 RU. The higher intestinal ACE2 mRNA expression in older patients may impact on their susceptibility to develop intestinal symptoms.
• Dewberry, L., Hilton, S., Gien, J., Liechty, K., & Marwan, A. (2019). Flap repair in congenital diaphragmatic hernia leads to lower rates of recurrence. Journal of Pediatric Surgery, 54(12). doi:10.1016/j.jpedsurg.2019.08.042
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  Background: Congenital diaphragmatic hernia (CDH) repair is technically challenging with different approaches for repair. The aim of this study was to compare outcomes between patch and flap repair. Methods: CDH repairs performed at a quaternary care children's hospital between 2008 and 2018 were reviewed. Seventy CDH repairs were analyzed after primary repairs were excluded (n = 52). Analysis included proportions or median with interquartile range and chi-square or Wilcoxon rank-sum test. Results: Comparing patch and flap repairs, demographic characteristics and hernia parameters were similar. Examining outcomes, length of stay, 30-day mortality, and 1-year mortality were all similar between groups, but total/symptomatic recurrence was higher in the patch group (10%/7% vs. 3%/0%), and the median time to recurrence was 3 months. A sub-analysis comparing those who recurred to those who did not demonstrated no significant difference between the two groups. Conclusion: Patients who undergo flap repair have a lower risk of recurrence compared to those who undergo patch repair, and this may be due to the ability of the flap to grow over time with the child. Type of Study: Treatment Study. Level of Evidence: III
• Hilton, S., Dewberry, L., Hodges, M., Hu, J., Xu, J., Liechty, K., & Zgheib, C. (2019). Mesenchymal stromal cells contract collagen more efficiently than dermal fibroblasts: Implications for cytotherapy. PLoS ONE, 14(7). doi:10.1371/journal.pone.0218536
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  Background Stem cell therapy is the next generation a well-established technique. Cell therapy with mesenchymal stem cells (MSC) has been demonstrated to enhance wound healing in diabetic mice, at least partly due to improved growth factor production. However, it is unclear whether MSC can biomechanically affect wound closure. Utilizing the well-established cell-populated collagen gel contraction model we investigated the interactions between MSC and the extracellular matrix. Methods Murine fetal liver-derived Mesenchymal Stem Cells (MSCs) or fetal Dermal Fibroblasts (DFs) were cultured in cell–populated collagen gels (CPCGs). The effect of cell density, conditioned media, growth factors (TGF-B1, FGF, PDGF-BB), cytoskeletal disruptors (colchicine, cytochalasin-D), and relative hypoxia on gel contraction were evaluated. Finally, we also measured the expression of integrin receptors and some growth factors by MSCs within the contracting gels. Results Our results show that at different densities, MSCs induced a higher gel contraction compared to DFs. Higher cell density resulted in faster and more complete contraction of CPCGs. Cytoskeletal inhibitors either inhibited or prevented MSC-mediated contraction in a dose dependent fashion. Growth factors, conditioned media from both MSC and DF, and hypoxia all influenced CPCG contraction. Discussion The results suggest that MSCs are capable of directly contributing to wound closure through matrix contraction, and they are more effective than DF. In addition, this study demonstrates the importance of how other factors such as cell concentration, cytokines, and oxygen tension can provide potential modulation of therapies to correct wound healing impairments.
• Hilton, S., Hodges, M., Dewberry, L., Handler, M., Galan, H., Zaretsky, M., Behrendt, N., Marwan, A., & Liechty, K. (2019). MOMS Plus: Single-Institution Review of Outcomes for Extended BMI Criteria for Open Fetal Repair of Myelomeningocele. Fetal Diagnosis and Therapy, 46(6). doi:10.1159/000499484
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  Background: In utero repair has become an accepted therapy to decrease the rate of ventriculoperitoneal shunting and improve neurologic function in select cases of myelomeningocele. The Management of Myelomeningocele Study (MOMS) trial excluded patients with a BMI >35 due to concerns for increased maternal complications and preterm delivery, limiting the population that may benefit from this intervention. Objectives: The aim of this study was to evaluate outcomes associated with extending the maternal BMI criteria to 40 in open fetal repair of myelomeningocele. Method: Retrospective review of fetal closure of myelomeningocele at a quaternary referral center between 2013 and 2016 with maternal BMI ranging from 35 to 40. Results: Eleven patients with a BMI >35 were identified. The average BMI was 37. The average maternal age at the time of evaluation was 27 years. The average gestational age at fetal surgery was 24 weeks. Gestational age at birth was an average of 32 weeks. There was one perinatal death immediately following the fetal intervention. The shunt rate at 1 year was 45% (5/11 patients). Conclusions: In this single-institution review of expanded BMI criteria for fetal repair of myelomeningocele, we did not observe any adverse maternal outcomes associated with maternal obesity; however, the gestational age at delivery was 2 weeks earlier compared to the MOMS trial.
• Hodges, M., Zgheib, C., Xu, J., Hu, J., Dewberry, L., Hilton, S., Allukian, M., Gorman, J., Gorman, R., & Liechty, K. (2019). Differential Expression of Transforming Growth Factor-β1 Is Associated With Fetal Regeneration After Myocardial Infarction. Annals of Thoracic Surgery, 108(1). doi:10.1016/j.athoracsur.2018.12.042
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  Background: Global extracellular matrix (ECM)-related gene expression is decreased after myocardial infarction (MI) in fetal sheep when compared with adult sheep. Transforming growth factor (TGF)-β1 is a key regulator of ECM; therefore we hypothesize that TGF-β1 is differentially expressed in adult and fetal infarcts after MI. Methods: Adult and fetal sheep underwent MI via ligation of the left anterior descending coronary artery. Expression of TGF-β1 and ECM-related genes was evaluated by ovine-specific microarray and quantitative polymerase chain reaction. Fibroblasts from the left ventricle of adult and fetal hearts were treated with TGF-β1 or a TGF-β1 receptor inhibitor (LY36497) to evaluate the effect of TGF-β1 on ECM-related genes. Results: Col1a1, col3a1, and MMP9 expression were increased in adult infarcts 3 and 30 days after MI but were upregulated in fetal infarcts only 3 days after MI. Three days after MI elastin expression was increased in adult infarcts. Despite upregulation in adult infarcts both 3 and 30 days after MI, TGF-β1 was not upregulated in fetal infarcts at any time point. Inhibition of the TGF-β1 receptor in adult cardiac fibroblasts decreased expression of col1a1, col3a1, MMP9, elastin, and TIMP1, whereas treatment of fetal cardiac fibroblasts with TGF-β1 increased expression of these genes. Conclusions: TGF-β1 is increased in adult infarcts compared with regenerative, fetal infarcts after MI. Although treatment of fetal cardiac fibroblasts with TGF-β1 conveys an adult phenotype, inhibition of TGF-β1 conveys a fetal phenotype to adult cardiac fibroblasts. Decreasing TGF-β1 after MI may facilitate myocardial regeneration by “fetalizing” the otherwise fibrotic, adult response to MI.
• Leu, S., Staerkle, R., Gaukel, S., Fink, L., Soll, C., Aasen, D., Liechty, K., Vitz, M., Ramseier, L., & Vuille-Dit-Bille, R. (2019). Impact of Sleep Deprivation on Surgical Laparoscopic Performance in Novices: A Computer-based Crossover Study. Surgical Laparoscopy, Endoscopy and Percutaneous Techniques, 29(3). doi:10.1097/sle.0000000000000657
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  The 24-hour work shifts are newly permitted to first-year surgical residents in the United States. Whether surgery novices' motor activity is affected by sleep deprivation is controversial.Materials and Methods:This study assesses sleep deprivation effects in computer-simulated laparoscopy in 20 surgical novices following 24 hours of sleep deprivation and after resting using a virtual-reality trainer. Participants were randomly assigned to perform simulator tests either well rested or sleep deprived first.Results:Of 3 different tasks performed, no significant differences in total time to complete the procedure and average speed of instruments were found. Instrument path length was longer following sleep deprivation (P=0.0435) in 1 of 3 tasks. Error rates (ie, noncauterized bleedings, perforations, etc.), as well as precision, and accuracy rates showed no difference. None of the assessed participants' characteristics affected simulator performance.Conclusions:Twenty-four hours of sleep deprivation does not affect laparoscopic performance of surgical novices as assessed by computer-simulation.
• Zgheib, C., Hilton, S., Dewberry, L., Hodges, M., Ghatak, S., Xu, J., Singh, S., Roy, S., Sen, C., Seal, S., & Liechty, K. (2019). Use of Cerium Oxide Nanoparticles Conjugated with MicroRNA-146a to Correct the Diabetic Wound Healing Impairment. Journal of the American College of Surgeons, 228(1). doi:10.1016/j.jamcollsurg.2018.09.017
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  Background: Diabetic wounds have become one of the most challenging public health issues of the 21st century, yet there is no effective treatment available. We have previously shown that the diabetic wound healing impairment is associated with increased inflammation and decreased expression of the regulatory microRNA miR-146a. We have conjugated miR-146a to cerium oxide nanoparticles (CNP-miR146a) to target reactive oxygen species (ROS) and inflammation. This study aimed to evaluate the consequences of CNP-miR146a treatment of diabetic wounds. Study Design: Eight-millimeter wounds were created on the dorsal skin of Db/Db mice and treated with PBS or differing concentrations of CNP-mir146a (1; 10; 100; or 1,000 ng) at the time of wounding. Rate of wound closure was measured until the wounds were fully healed. At 4 weeks post-healing, a dumbbell-shaped skin sample was collected, with the healed wound in the center, and an Instron 5942 testing unit was used to measure the maximum load and modulus. Results: Our data showed that diabetic wounds treated with PBS or 1 ng CNP-miR146a took 18 days to heal. Treatment with 10, 100, or 1,000 ng of CNP+miR-146a effectively enhanced healing, and wounds were fully closed at day 14 post-wounding. The healed skin from the CNP-miR146a-treated group showed a trend of improved biomechanical properties (increased maximum load and modulus), however it did not reach significance. Conclusions: We found that a 100-ng dose of CNP-miR146a improved diabetic wound healing and did not impair the biomechanical properties of the skin post-healing. This nanotechnology-based therapy is promising, and future studies are warranted to transfer this therapy to clinical application.
• Deeney, S., Howley, L., Hodges, M., Liechty, K., Marwan, A., Gien, J., Kinsella, J., & Crombleholme, T. (2018). Impact of Objective Echocardiographic Criteria for Timing of Congenital Diaphragmatic Hernia Repair. Journal of Pediatrics, 192(Issue). doi:10.1016/j.jpeds.2017.09.004
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  Objective To assess the impact of specific echocardiographic criteria for timing of congenital diaphragmatic hernia repair on the incidence of acute postoperative clinical decompensation from pulmonary hypertensive crisis and/or acute respiratory decompensation, with secondary outcomes including survival to discharge, duration of ventilator support, and length of hospitalization. Study design The multidisciplinary congenital diaphragmatic hernia management team instituted a protocol in 2012 requiring the specific criterion of echocardiogram-estimated pulmonary artery pressure ≤80% systemic blood pressure before repairing congenital diaphragmatic hernias. A retrospective review of 77 neonatal patients with Bochdalek hernias repaired between 2008 and 2015 were reviewed: group 1 included patients repaired before protocol implementation (n = 25) and group 2 included patients repaired after implementation (n = 52). Results The groups had similar baseline characteristics. Postoperative decompensation occurred less often in group 2 compared with group 1 (17% vs 48%, P =.01). Adjusted analysis accounting for repair type, liver herniation, and prematurity yielded similar results (15% vs 37%, P =.04). Group 2 displayed a trend toward improved survival to 30 days postoperatively, though this did not reach statistical significance (94% vs 80%, P =.06). Patient survival to discharge, duration of ventilator support, and length of hospitalization were not different between groups. Conclusions The implementation of a protocol requiring echocardiogram-estimated pulmonary arterial pressure ≤80% of systemic pressure before congenital diaphragmatic hernia repair may reduce the incidence of acute postoperative decompensation, although there was no difference in longer-term secondary outcomes, including survival to discharge.
• Dewberry, L., Bunn, J., Galambos, C., Galan, H. L., Zaretsky, M. V., Behrendt, N., Reynolds, R., Meyers, M., Marwan, A. I., & Liechty, K. W. (2018). Concurrent extrapulmonary bronchopulmonary sequestration and bronchogenic cyst. Journal of Pediatric Surgery Case Reports, 34(Issue). doi:10.1016/j.epsc.2018.04.013
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  A prenatal ultrasound (US) at 21 weeks estimated gestational age (EGA) identified a left intrathoracic homogenously echogenic microcystic mass with mediastinal shift and a CPAM volume ratio (CVR) of 0.78 (Fig. 1). A fetal magnetic resonance imaging (MRI) study confirmed the US findings. MRI and US were repeated at 35 weeks EGA demonstrating a CVR of 0.36 and a spontaneous decrease in size of the previously identified mass. Moreover, an intralesional, fluid filled dilated bronchus was identified that connected to the esophagus and showed mild branching. This finding was thought to represent an esophageal bronchus. Prenatal echocardiogram demonstrated normal cardiac anatomy and function. The patient was delivered vaginally at 38 weeks EGA with no respiratory distress after delivery. The patient was discharged at this time with planned outpatient follow-up. Outpatient contrast CT at three months of age demonstrated a left BPS supplied by the celiac axis and a fluid filled branching structure within the sequestration suspicious for esophageal bronchus. At four months of age, the patient underwent a left, muscle sparing thoracotomy, where the bronchopulmonary sequestration was excised and an adjacent cyst was enucleated. Pathology demonstrated extralobar bronchopulmonary sequestration with a separate foregut malformation most consistent with bronchogenic cyst.
• Zaretsky, M., Liechty, K., Galan, H., Behrendt, N., Reeves, S., Marwan, A., Wilkinson, C., Handler, M., Lagueux, M., & Crombleholme, T. (2018). Modified Hysterotomy Closure Technique for Open Fetal Surgery. Fetal Diagnosis and Therapy, 44(2). doi:10.1159/000479683
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  Objective: We reviewed our experience with open fetal surgical myelomeningocele repair to assess the efficacy of a new modification of the hysterotomy closure technique regarding hysterotomy complication rates at the time of cesarean delivery. Methods: A modification of the standard hysterotomy closure was performed on all patients undergoing prenatal myelomeningocele repair. The closure consisted of an interrupted full-thickness #0 polydioxanone (PDS) retention suture as well as a running #0 PDS suture to re-approximate the myometrial edges, and the modification was a third imbricating layer resulting in serosal-to-serosal apposition. A standard omental patch was placed per our routine. Both operative reports and verbal descriptions of hysterotomy from delivering obstetricians were reviewed. Results: A total of 49 patients underwent prenatal repair of myelomeningocele, 43 having adequate follow-up for evaluation. Of those, 95.4% had completely intact hysterotomy closures, with only 1 partial dehiscence (2.3%) and 1 thinned scar (2.3%). There were no instances of uterine rupture. Discussion: In patients undergoing this modified hysterotomy closure technique, a much lower than expected complication rate was observed. This simple modified closure technique may improve hysterotomy healing and reduce obstetric morbidity.
• Abou Chaar, M., Meyers, M., Tucker, B., Galan, H., Liechty, K., Crombleholme, T., & Marwan, A. (2017). Twin pregnancy complicated by esophageal atresia, duodenal atresia, gastric perforation, and hypoplastic left heart structures in one twin: a case report and review of the literature. Journal of Medical Case Reports, 11(1). doi:10.1186/s13256-016-1195-x
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  Background: The antenatal diagnosis of a combined esophageal atresia without tracheoesophageal fistula and duodenal atresia with or without gastric perforation is a rare occurrence. These diagnoses are difficult and can be suspected on ultrasound by nonspecific findings including a small stomach and polyhydramnios. Fetal magnetic resonance imaging adds significant anatomical detail and can aid in the diagnosis of these complicated cases. Upon an extensive literature review, there are no reports documenting these combined findings in a twin pregnancy. Therefore we believe this is the first case report of an antenatal diagnosis of combined pure esophageal and duodenal atresia in a twin gestation. Case presentation: We present a case of a 30-year-old G1P0 white woman at 22-week gestation with a monochorionic-diamniotic twin pregnancy discordant for esophageal atresia, duodenal atresia with gastric perforation, hypoplastic left heart structures, and significant early gestation maternal polyhydramnios. In this case, fetal magnetic resonance imaging was able to depict additional findings including area of gastric wall rupture, hiatal hernia, dilation of the distal esophagus, and area of duodenal obstruction and thus facilitated the proper diagnosis. After extensive counseling at our multidisciplinary team meeting, the parents elected to proceed with radiofrequency ablation of the anomalous twin to maximize the survival of the normal co-twin. The procedure was performed successfully with complete cessation of flow in the umbilical artery and complete cardiac standstill in the anomalous twin with no detrimental effects on the healthy co-twin. Conclusions: Prenatal diagnosis of complex anomalies in twin pregnancies constitutes a multitude of ethical, religious, and cultural factors that come into play in the management of these cases. Fetal magnetic resonance imaging provides detailed valuable information that can assist in management options including possible prenatal intervention. The combination of a cystic structure with peristalsis-like movement above the diaphragm (for example, “the upper thoracic pouch sign”), polyhydramnios, and progressive distention of the stomach and duodenum should increase suspicion for a combined pure esophageal and duodenal atresia.
• Balaji, S., Wang, X., King, A., Le, L., Bhattacharya, S., Moles, C., Butte, M., De JesusPerez, V., Liechty, K., Wight, T., Crombleholme, T., Bollyky, P., & Keswani, S. (2017). Interleukin-10-mediated regenerative postnatal tissue repair is dependent on regulation of hyaluronan metabolism via fibroblast-specific STAT3 signaling. FASEB Journal, 31(3). doi:10.1096/fj.201600856r
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  The cytokine IL-10 has potent antifibrotic effects in models of adult fibrosis, but themechanisms of action are unclear. Here, we report a novel finding that IL-10 triggers a signal transducer and activator of transcription 3 (STAT3)-dependent signaling pathway that regulates hyaluronan (HA) metabolism and drives adult fibroblasts to synthesize an HA-rich pericellular matrix, which mimics the fetal regenerative wound healing phenotype with reduced fibrosis. By using cre-lox-mediated novel, inducible, fibroblast-, keratinocyte-, and wound-specific STAT3- knockdown postnatalmice-plus syngeneic fibroblast cell-Transplantmodels-we demonstrate that the regenerative effects of IL-10 in postnatal wounds are dependent on HA synthesis and fibroblast-specific STAT3-dependent signaling. The importance of IL-10-inducedHAsynthesis for regenerativewound healing is demonstrated by inhibition of HA synthesis in a murine wound model by administering 4-methylumbelliferone. Although IL-10 and STAT3 signalingwere intact, the antifibrotic repair phenotype that is induced by IL-10 overexpressionwas abrogated in this model. Our data show a novel role for IL-10 beyond its accepted immune-regulatorymechanism. The opportunity for IL-10 to regulate a fibroblast-specific formation of a regenerative,HA-rich wound extracellularmatrixmay lead to the developmentof innovative therapies to attenuatepostnatal fibrosis inorgansystemsordiseases inwhichdysregulated inflammation andHAintersect.
• Hodges, M. M., Crombleholme, T. M., Marwan, A. I., Mirsky, D., Meyers, M., Behrendt, N., French, B., Kelley, P., & Liechty, K. W. (2017). Massive facial teratoma managed with the ex utero intrapartum treatment (EXIT) procedure and use of a 3-dimensional printed model for planning of staged debulking. Journal of Pediatric Surgery Case Reports, 17(Issue). doi:10.1016/j.epsc.2016.11.013
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  Teratomas are the most frequent solid tumor found in neonates. However, only 1.5% of neonatal teratomas originate from facial structures. Neonatal facial teratomas are associated with polyhydramnios, preterm birth, pulmonary hypoplasia, cleft palate, cleft lip, and life-threatening airway compromise. The overall survival reported with these lesions has been between 17 and 87.5%; however survival in the setting of antenatally diagnosed facial teratomas has only been described anecdotally. We present a case of an antenatally diagnosed massive facial teratoma originating from the pterygomaxillary fossa, which was associated with polyhydramnios and pre-term birth. We managed this complex tumor with an ex utero intrapartum treatment (EXIT) procedure, multidisciplinary medical and surgical team, and staged excision and reconstruction aided by use of a 3-dimensional printed model. Here we review the surgical management of this rare and complex tumor.
• Xu, J., Zgheib, C., Hodges, M., Caskey, R., Hu, J., & Liechty, K. (2017). Mesenchymal stem cells correct impaired diabetic wound healing by decreasing ECM proteolysis. Physiological Genomics, 49(10). doi:10.1152/physiolgenomics.00090.2016
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  Impaired diabetic wound healing is associated with a dermal extracellular matrix protein profile favoring proteolysis; within the healing diabetic wound, this is represented by an increase in activated matrix metalloproteinase (MMPs). Treatment of diabetic wounds with mesenchymal stem cells (MSCs) has been shown to improve wound healing; however, there has not yet been an assessment of their ability to correct dysregulation of MMPs in diabetic wounds. Furthermore, there has been no prior assessment of the role of microRNA29b (miR-29b), an inhibitory regulatory molecule that targets MMP-9 mRNA. Using in vitro models of fibroblast coculture with MSCs and in vivo murine wound healing models, we tested the hypothesis that MSCs correct dysregulation of MMPs in a microRNA-29b-dependent mechanism. In this study, we first demonstrated that collagen I and III protein content is significantly reduced in diabetic wounds, and treatment with MSCs significantly improves collagen I content in both nondiabetic and diabetic wounds. We then found that MMP-9 gene expression and protein content were significantly upregulated in diabetic wounds, indicating elevated proteolysis. Treatment with MSCs resulted in a decrease in MMP-9 gene expression and protein content level in diabetic wounds 3 and 7 days after wounding. Zymographic analysis indicated that MSC treatment also decreased the amount of activated MMP-9 present in diabetic wounds. Furthermore, miR-29b expression was inversely associated with MMP-9 gene expression; miR-29b expression was decreased in diabetic wounds and diabetic fibroblast. Following treatment of diabetic wounds with MSCs, as well as in diabetic fibroblasts cocultured with MSCs, miR-29b was significantly increased. These findings suggest a potential mechanism through which MSCs enhance diabetic wound healing by improving collagen I content in diabetic wounds through decreasing MMP-9 expression and increasing miR-29b expression.
• Zgheib, C., Hodges, M., Allukian, M., Xu, J., Spiller, K., Gorman, J., Gorman, R., & Liechty, K. (2017). Cardiac Progenitor Cell Recruitment Drives Fetal Cardiac Regeneration by Enhanced Angiogenesis. Annals of Thoracic Surgery, 104(6). doi:10.1016/j.athoracsur.2017.05.040
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  Background In contrast to adults, the fetal response to myocardial infarction (MI) is regenerative, requiring the recruitment of cardiac progenitor cells to replace infarcted myocardium. Macrophage contribution to tissue repair depends on their phenotype: M1 are proinflammatory and initiate angiogenesis; M2a are profibrotic and contribute to blood vessels maturation; and M2c are proremodeling and proangiogenesis. The goal of the present study was to expand on this work by examining cardiac progenitor cells recruitment, and the role of macrophages in promoting angiogenesis and cardiac regeneration in the fetal heart after MI. Methods Fetal and adult sheep underwent MI and were sacrificed 3 or 30 days after MI. Some fetal hearts received stromal cell-derived factor-1α-inhibitor treatment. The microvasculature was evaluated by micro–computed tomography, gene expression was evaluated by real-time polymerase chain reaction, and vessels counts were evaluated by immunohistochemistry. Results Micro–computed tomography analysis showed restoration of microvasculature in fetal hearts after MI. Vascular endothelial growth factor-α increased, and the expression of tissue markers associated with the M1, M2a, and M2c macrophage phenotypes were elevated at day 3 after MI, but returned to baseline by 30 days after MI. In contrast, adult hearts after MI exhibited low vascular endothelial growth factor-α and persistent upregulation of all macrophage markers, consistent with prolonged inflammation, fibrosis, and remodeling. Inhibition of stromal cell-derived factor-1α in fetal infarcts prevented angiogenesis, decreased vascular endothelial growth factor-α, and was associated with a sustained increase in M1, M2a, and M2c markers after MI. Conclusions Changes in angiogenesis and macrophage phenotype-related gene expression after MI are important for the fetal regenerative response to MI and are mediated at least in part by cardiac progenitor cells recruitment.
• Zgheib, C., Hodges, M., Hu, J., Liechty, K., & Xu, J. (2017). Long non-coding RNA Lethe regulates hyperglycemia-induced reactive oxygen species production in macrophages. PLoS ONE, 12(5). doi:10.1371/journal.pone.0177453
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  Type 2 diabetes mellitus is a complex, systemic metabolic disease characterized by insulin resistance and resulting hyperglycemia, which is associated with impaired wound healing. The clinical complications associated with hyperglycemia are attributed, in part, to the increased production of reactive oxygen species (ROS). Recent studies revealed that long non-coding RNAs (lncRNAs) play important regulatory roles in many biological processes. Specifically, lncRNA Lethe has been described as exhibiting an anti-inflammatory effect by binding to the p65 subunit of NFκB and blocking its binding to DNA and the subsequent activation of downstream genes. We therefore hypothesize that dysregulation of Lethe's expression plays a role in hyperglycemia-induced ROS production. To test our hypothesis, we treated RAW264.7 macrophages with low glucose (5 mM) or high glucose (25 mM) for 24h. High glucose conditions significantly induced ROS production and NOX2 gene expression in RAW cells, while significantly decreasing Lethe gene expression. Overexpression of Lethe in RAW cells eliminated the increased ROS production induced by high glucose conditions, while also attenuating the upregulation of NOX2 expression. Similar results was found also in non-diabetic and diabetic primary macrophage, bone marrow derived macrophage (BMM). Furthermore, overexpression of Lethe in RAW cells treated with high glucose significantly reduced the translocation of p65-NFkB to the nucleus, which resulted in decreased NOX2 expression and ROS production. Interestingly, these findings are consistent with the decreased Lethe gene expression and increased NOX2 gene expression observed in a mouse model of diabetic wound healing. These findings provide the first evidence that lncRNA Lethe is involved in the regulation of ROS production in macrophages through modulation of NOX2 gene expression via NFκB signaling. Moreover, this is the first report to describe a role of lncRNAs, in particular Lethe, in impaired diabetic wound healing. Further studies are warranted to determine if correction of Lethe expression in diabetic wounds could improve healing.
• Hodges, M. M., Crombleholme, T. M., Meyers, M., Kulungowski, A., Marwan, A. I., Nakano, T., Behrendt, N., & Liechty, K. W. (2016). Massive fetal chylothorax successfully treated with postnatal talc pleurodesis: A case report and review of the literature. Journal of Pediatric Surgery Case Reports, 9(Issue). doi:10.1016/j.epsc.2016.03.014
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  Despite the rapid advances in fetal medicine and pediatric surgery, congenital chylothoraces have an associated mortality of 22-65% and an increased morbidity resulting from pulmonary hypoplasia, severe infections secondary to immune globulin deficiencies, protein malnutrition, and coagulopathy. While the mainstay of therapy is medical management, large volume chylothoraces often require surgical management. In both the prenatal and postnatal periods, the recommended management of congenital chylothoraces is still controversial. We present a case of a prenatally diagnosed large chylothorax associated with a cervical lymphatic malformation. In our patient, the chylothorax persisted despite optimal postnatal medical management with drainage by tube thoracostomy, TPN, and octreotide. Adjuvant therapies included sirolimus and sclerotherapy directed toward the treatment of the macrocystic lymphatic malformation. We report the first case of a persistent congenital chylothorax associated with a lymphatic malformation successfully treated with thoracoscopic talc pleurodesis and sclerotherapy.
• Zgheib, C., Hodges, M., Hu, J., Beason, D. P., Soslowsky, L. J., Liechty, K. W., & Xu, J. (2016). Mechanisms of mesenchymal stem cell correction of the impaired biomechanical properties of diabetic skin: The role of miR-29a. Wound Repair and Regeneration, 24(Issue 2). doi:10.1111/wrr.12412
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  Diabetic skin has impaired wound healing properties following injury. We have further shown that diabetic skin has weakened biomechanical properties at baseline. We hypothesize that the biomechanical properties of diabetic skin decline during the progression of the diabetic phenotype, and that this decline is due to the dysregulation of miR-29a, resulting in decreased collagen content. We further hypothesize that treatment with mesenchymal stem cells (MSCs) may improve diabetic wound healing by correction of the dysregulated miR-29a expression. We analyzed the biomechanical properties, collagen gene expression, collagen protein production, and miR-29a levels in skin harvested from 6 to 18 week old mice during the development of the diabetic phenotype. We also examined the correction of these impairments by both MSC treatment and the inhibition of miR-29a. Diabetic skin demonstrated a progressive impairment of biomechanical properties, decreased collagen content, and increased miR-29a levels during the development of the diabetic phenotype. MSC treatment decreased miR-29a levels, increased collagen content, and corrected the impaired biomechanical properties of diabetic skin. Additionally, direct inhibition of miR-29a also increased collagen content in diabetic skin. This decline in the biomechanical properties of diabetic skin during the progression of diabetes may increase the susceptibility of diabetic skin to injury and miR-29a appears to play a key role in this process.
• Caskey, R., Zgheib, C., Morris, M., Allukian, M., Dorsett-Martin, W., Xu, J., Wu, W., & Liechty, K. (2014). Dysregulation of collagen production in diabetes following recurrent skin injury: Contribution to the development of a chronic wound. Wound Repair and Regeneration, 22(4). doi:10.1111/wrr.12199
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  Recurrent injury has been implicated in the development of chronic diabetic wounds. We have developed a chronic diabetic wound model based upon recurrent injury in diabetic mice. We hypothesized that dysregulation of collagen production at both the mRNA and microRNA levels contributes to the development of chronic diabetic wounds. To test this, both diabetic and nondiabetic mice were made to undergo recurrent injury. Real-time PCR for TGF-β1, SMAD-3, Col1α1, Col3α1, microRNA-25, and microRNA-29a and Western blot for collagen I and III were performed 7 days following each injury. Diabetic wounds displayed decreased collagen at all time points. This was associated with dysregulated collagen production at both the gene and microRNA levels at all time points. Following the final injury, however, diabetic collagen production significantly improved. This appeared to be due to a substantial decrease in both microRNAs as well as an increase in the expression of collagen pathway genes. That dysregulated collagen production progressed throughout the course of wounding suggests that this is one factor contributing to the development of chronic diabetic wounds. Future studies using this model will allow for the determination of other factors that may also contribute to the development and/or persistence of chronic diabetic wounds. © 2014 by the Wound Healing Society.
• Connizzo, B., Bhatt, P., Liechty, K., & Soslowsky, L. (2014). Diabetes alters mechanical properties and collagen fiber re-alignment in multiple mouse tendons. Annals of Biomedical Engineering, 42(9). doi:10.1007/s10439-014-1031-7
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  Tendons function to transfer load from muscle to bone through their complex composition and hierarchical structure, consisting mainly of type I collagen. Recent evidence suggests that type II diabetes may cause alterations in collagen structure, such as irregular fibril morphology and density, which could play a role in the mechanical function of tendons. Using the db/db mouse model of type II diabetes, the diabetic skin was found to have impaired biomechanical properties when compared to the non-diabetic group. The purpose of this study was to assess the effect of diabetes on biomechanics, collagen fiber re-alignment, and biochemistry in three functionally different tendons (Achilles, supraspinatus, patellar) using the db/db mouse model. Results showed that cross-sectional area and stiffness, but not modulus, were significantly reduced in all three tendons. However, the tendon response to load (transition strain, collagen fiber re-alignment) occurred earlier in the mechanical test, contrary to expectations. In addition, the patellar tendon had an altered response to diabetes when compared to the other two tendons, with no changes in fiber re-alignment and decreased collagen content at the midsubstance of the tendon. Overall, type II diabetes alters tendon mechanical properties and the dynamic response to load. © 2014 Biomedical Engineering Society.
• Morris, M., Allukian, M., Herdrich, B., Caskey, R., Zgheib, C., Xu, J., Dorsett-Martin, W., Mitchell, M., & Liechty, K. (2014). Modulation of the inflammatory response by increasing fetal wound size or interleukin-10 overexpression determines wound phenotype and scar formation. Wound Repair and Regeneration, 22(3). doi:10.1111/wrr.12180
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  Wound size impacts the threshold between scarless regeneration and reparative healing in the fetus with increased inflammation showed in fetal scar formation. We hypothesized that increased fetal wound size increases pro-inflammatory and fibrotic genes with resultant inflammation and fibroplasia and that transition to scar formation could be reversed by overexpression of interleukin-10 (IL-10). To test this hypothesis, 2-mm and 8-mm dermal wounds were created in mid-gestation fetal sheep. A subset of 8-mm wounds were injected with a lentiviral vector containing the IL-10 transgene (n=4) or vehicle (n=4). Wounds were harvested at 3 or 30 days for histology, immunohistochemistry, analysis of gene expression by microarray, and validation with real-time polymerase chain reaction. In contrast to the scarless 2-mm wounds, 8-mm wounds showed scar formation with a differential gene expression profile, increased inflammatory cytokines, decreased CD45+ cells, and subsequent inflammation. Lentiviral-mediated overexpression of the IL-10 gene resulted in conversion to a regenerative phenotype with decreased inflammatory cytokines and regeneration of dermal architecture. In conclusion, increased fetal wounds size leads to a unique gene expression profile that promotes inflammation and leads to scar formation and furthermore, these results show the significance of attenuated inflammation and IL-10 in the transition from fibroplasia to fetal regenerative healing. © 2014 by the Wound Healing Society.
• Zgheib, C., Allukian, M., Xu, J., Morris, M., Caskey, R., Herdrich, B., Hu, J., Gorman, J., Gorman, R., & Liechty, K. (2014). Mammalian fetal cardiac regeneration after myocardial infarction is associated with differential gene expression compared with the adult. Annals of Thoracic Surgery, 97(5). doi:10.1016/j.athoracsur.2014.01.013
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  Background In adults, myocardial infarction (MI) results in a brisk inflammatory response, myocardium loss, and scar formation. We have recently reported the first mammalian large-animal model of cardiac regeneration after MI in fetal sheep. We hypothesize that the ability of the fetus to regenerate functional myocardium after MI is owing to differential gene expression regulating the response to MI in the fetus compared with the adult. Methods Myocardial infarction was created in adult (n = 4) or early gestation fetal (n = 4) sheep. Tissue was harvested after 3 or 30 days, and RNA was extracted for microarray, followed by principal component analysis and global gene expression analysis for the following gene ontology terms: response to wounding, inflammatory response, extracellular matrix, cell cycle, cell migration, cell proliferation, and apoptosis. Results Principal component analysis demonstrated that the global gene expression pattern in adult infarcts was distinctly different from the uninfarcted region at 3 days and remained different at 30 days after MI. In contrast, gene expression in the fetal infarct was different from the uninfarcted region at 3 days, but by 30 days it returned to a baseline expression pattern similar to the uninfarcted region. Three days after MI there was an increase in the expression of genes related to all gene ontology terms in fetal and adult infarcts, but this increase was much more pronounced in adults. By 30 days, the fetal gene expression returned to baseline, whereas in the adult it remained significantly elevated. Conclusions These data demonstrate that the global gene expression pattern is dramatically different in the fetal regenerative response to MI compared with the adult response and may partly be responsible for the regeneration. © 2014 by The Society of Thoracic Surgeons.
• Allukian, M., Xu, J., Morris, M., Caskey, R., Dorsett-Martin, W., Plappert, T., Griswold, M., Gorman, J., Gorman, R., & Liechty, K. (2013). Mammalian cardiac regeneration after fetal myocardial infarction requires cardiac progenitor cell recruitment. Annals of Thoracic Surgery, 96(1). doi:10.1016/j.athoracsur.2013.04.005
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  Background: In contrast to the adult, fetal sheep consistently regenerate functional myocardium after myocardial infarction. We hypothesize that this regeneration is due to the recruitment of cardiac progenitor cells to the infarct by stromal-derived factor-1α (SDF-1α) and that its competitive inhibition will block the regenerative fetal response. Methods: A 20% apical infarct was created in adult and fetal sheep by selective permanent coronary artery ligation. Lentiviral overexpression of mutant SDF-1α competitively inhibited SDF-1α in fetal infarcts. Echocardiography was performed to assess left ventricular function and infarct size. Cardiac progenitor cell recruitment and proliferation was assessed in fetal infarcts at 1 month by immunohistochemistry for nkx2.5 and 5-bromo-2-deoxyuridine. Results: Competitive inhibition of SDF-1α converted the regenerative fetal response into a reparative response, similar to the adult. SDF-inhibited fetal infarcts demonstrated significant infarct expansion by echocardiography (p < 0.001) and a significant decrease in the number of nkx2.5+ cells repopulating the infarct (p < 0.001). Conclusions: The fetal regenerative response to myocardial infarction requires the recruitment of cardiac progenitor cells and is dependent on SDF1α. This novel model of mammalian cardiac regeneration after myocardial infarction provides a powerful tool to better understand cardiac progenitor cell biology and to develop strategies to cardiac regeneration in the adult. © 2013 The Society of Thoracic Surgeons.
• Caskey, R., & Liechty, K. (2013). Novel animal models for tracking the fate and contributions of bone marrow derived cells in diabetic healing. Methods in Molecular Biology, 1037. doi:10.1007/978-1-62703-505-7_6
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  There is a vast wealth of information to be gained by tracking both the fate and contribution of individual cell types to the wound healing response. This is particularly important in research focused on impaired healing, such as diabetic wound healing, where the number or function of one or more specific cell types may be abnormal and contribute to the observed healing derangements. Specifically, diabetic wounds have been shown to have an overactive inflammatory response and decreased angiogenesis. The ability to track specific cell types participating in these responses would dramatically improve our understanding of the cellular derangements in diabetic healing. In this chapter, we review two novel chimeric models based on the leptin deficient Db/Db mouse. The use of these models allows for the tracking of bone marrow derived inflammatory and progenitor cell populations as well as the determination of the molecular contributions of these cell populations to the wound healing response. © 2013 Springer Science+Business Media New York.
• Caskey, R., Allukian, M., Lind, R., Herdrich, B., Xu, J., Radu, A., Mitchell, M., & Liechty, K. (2013). Lentiviral-mediated over-expression of hyaluronan synthase-1 (HAS-1) decreases the cellular inflammatory response and results in regenerative wound repair. Cell and Tissue Research, 351(1). doi:10.1007/s00441-012-1504-7
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  Fetal wounds have been found to have increased levels of high-molecular-weight hyaluronan (HMW-HA) compared with those of adults. The primary enzyme responsible for producing HMW-HA is hyaluronic acid synthase-1 (HAS-1). We hypothesized that over-expression of HAS-1 in adult dermal wounds would decrease inflammation and promote regenerative healing. To test this hypothesis, the flanks of adult C57Bl/6 mice were treated with a lentiviral construct containing either HAS-1-GFP or GFP transgenes. After 48 h, a 4-mm excisional wound was made at the site of treatment. Wounds were harvested at days 3, 7, or 28 after wounding. Wound phenotype was assessed by histology to examine tissue architecture and immunohistochemistry for CD45. At 7 and 28 days, lenti-HAS-1-treated wounds demonstrated the restoration of the normal dermal elements and organized collagen fiber orientation. In contrast, the lenti-GFP-treated wounds lacked normal dermal architecture and demonstrated a disorganized collagen scar. At 3 and 7 days, wounds treated with lenti-HAS-1 exhibited a significant decrease in the number of inflammatory cells when compared with wounds treated with lenti-GFP. Thus, HAS-1 over-expression promotes dermal regeneration, in part by decreasing the inflammatory response and by recapitulation of fetal extracellular matrix HMW-HA content. © 2012 Springer-Verlag Berlin Heidelberg.
• Brewer, J., Liechty, K., & Bofill, J. (2012). EXIT procedure: a report of the first three Mississippi cases.. Journal of the Mississippi State Medical Association, 53(4).
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  The University of Mississippi Medical Center has initiated a state-of-the-art fetal center. This project involves collaboration between multiple disciplines including anesthesiology, pediatric surgery, maternal-fetal medicine, radiology, neonatology, genetics, pediatric cardiology and other pediatric subspecialties, nursing, and social work. Complicated fetal patients from throughout the southeastern U.S.A. may be referred to this center and benefit from new and innovative interventions that have not been available to this region in the past. The first three EXIT (ex-utero intrapartum treatment) procedures were recently performed at Batson Children's Hospital at the University of Mississippi Medical Center. Our objective is to share our recent experiences with this novel procedure and to detail some of the basics of an EXIT delivery.
• Zouein, F., Zgheib, C., Liechty, K., & Booz, G. (2012). Post-Infarct Biomaterials, Left Ventricular Remodeling, and Heart Failure: Is Good Good Enough?. Congestive Heart Failure, 18(5). doi:10.1111/j.1751-7133.2012.00298.x
• Bermudez, D., Canning, D., & Liechty, K. (2011). Age and pro-inflammatory cytokine production: Wound-healing implications for scar-formation and the timing of genital surgery in boys. J Pediatr Urol, 7(3). doi:10.1016/j.jpurol.2011.02.013
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  Purpose: Fewer complications occur when hypospadias is repaired early in childhood. We hypothesize that the production of pro-inflammatory cytokines by fibroblasts from neonatal foreskin is decreased compared with fibroblasts from older boys. We believe that these age-related differences may explain the greater risk of complications following repair in older boys. Materials and methods: With IRB approval, we collected 15 samples of foreskin from boys undergoing elective circumcision. They were divided into one of three groups: a neonatal group (under 28 days), an intermediate age group (6 months-1 year), and an older age group (7-17-years-olds). Fibroblasts were cultured then incubated for 16 h with serum-free medium containing 0, 0.1, 1 or 10 ng/mL of PDGF. Supernatants were analyzed for production of IL-6 and IL-8 with quantitative ELISA. Fibroblasts had RT-PCR performed for IL-6, IL-8, IL-10, TGF-β1, TGF-β3 and TNF-α. Results: Fibroblasts from neonatal foreskin produced significantly less IL-6 and IL-8 at baseline and following stimulation with PDGF compared to the intermediate and older age groups (P < 0.01). Real-time PCR revealed greater expression of IL-6, IL-8, TNF-α and TGF-β1 mRNA in the older age groups (P < 0.05). Conclusions: There is a clear association between age and production of pro-inflammatory cytokines by genitourinary fibroblasts. This relationship exists at baseline and following stimulation with PDGF. The dramatic difference in levels of pro-inflammatory factors may explain the observed age-associated differences in wound scarring and stricture formation following hypospadias repair. Further clinical studies are needed, however, to validate this finding. © 2011 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
• Bermudez, D., Herdrich, B., Xu, J., Lind, R., Beason, D., Mitchell, M., Soslowsky, L., & Liechty, K. (2011). Impaired biomechanical properties of diabetic skin: Implications in pathogenesis of diabetic wound complications. American Journal of Pathology, 178(5). doi:10.1016/j.ajpath.2011.01.015
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  Diabetic skin is known to have deficient wound healing properties, but little is known of its intrinsic biomechanical properties. We hypothesize that diabetic skin possesses inferior biomechanical properties at baseline, rendering it more prone to injury. Skin from diabetic and nondiabetic mice and humans underwent biomechanical testing. Real-time PCR was performed for genes integral to collagen synthesis and degradation. MMP-2 and MMP-9, and TIMP-1 protein levels were assessed by ELISA and zymography. Collagen I and III content was assessed using Western blot analysis. At baseline, both murine and human diabetic skin was biomechanically inferior compared to nondiabetic skin, with decreased maximum stress and decreased modulus (P < 0.001 and < 0.05, respectively). Surprisingly, the expression of genes involved in collagen synthesis were significantly up-regulated, and genes involved in collagen degradation were significantly down-regulated in murine diabetic skin (P < 0.01). In addition, MMP-2 and MMP-9/TIMP-1 protein ratios were significantly lower in murine diabetic skin (P < 0.05). Collagen I levels and I:III ratios were lower in diabetic skin (P < 0.05). These findings suggest that the predisposition of diabetics to wounds may be the result of impaired tissue integrity at baseline, and are due, in part, to a defect in the regulation of collagen protein synthesis at the post-transcriptional level. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.
• Bermudez, D., Xu, J., Herdrich, B., Radu, A., Mitchell, M., & Liechty, K. (2011). Inhibition of stromal cell-derived factor-1α further impairs diabetic wound healing. Journal of Vascular Surgery, 53(3). doi:10.1016/j.jvs.2010.10.056
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  Objective: Impaired diabetic wound healing is associated with abnormal stromal cell-derived factor (SDF)-1α production, decreased angiogenesis, and chronic inflammation. Lentiviral-mediated overexpression of SDF-1α can correct the impairments in angiogenesis and healing in diabetic wounds. We hypothesized that SDF-1α is a critical component of the normal wound-healing response and that inhibition of SDF-1α would further delay the wound-healing process. Methods: dB/Db diabetic mice and Db/+ nondiabetic mice were wounded with an 8-mm punch biopsy and the wounds treated with a lentiviral vector containing either the green fluorescent protein (GFP) or SDF-1α inhibitor transgene. The inhibitor transgene is a mutant form of SDF-1α that binds, but does not activate, the CXCR4 receptor. Computerized planimetry was used to measure wound size daily. Wounds were analyzed at 3 and 7 days by histology and for production of inflammatory markers using real-time polymerase chain reaction. The effect of the SDF-1α inhibitor on cellular migration was also assessed. Results: Inhibition of SDF-1α resulted in a significant decrease in the rate of diabetic wound healing, (3.8 vs 6.5 cm 2/day in GFP-treated wounds; P = .04), and also impaired the early phase of nondiabetic wound healing. SDF-1α inhibition resulted in fewer small-caliber vessels, less granulation tissue formation, and increased proinflammatory gene expression of interleukin-6 and macrophage inflammatory protein-2 in the diabetic wounds. Conclusions: The relative level of SDF-1α in the wound plays a key role in the wound-healing response. Alterations in the wound level of SDF-1α, as seen in diabetes or by SDF-1α inhibition, impair healing by decreasing cellular migration and angiogenesis, leading to increased production of inflammatory cytokines and inflammation. Inhibition of SDF-1α further impairs diabetic wound healing. © 2011 Society for Vascular Surgery.
• Caskey, R., & Liechty, K. (2011). Multiple strategies must be pursued in the development of cellular therapies. Cytotherapy, 13(2). doi:10.3109/14653249.2010.542295
• Danzer, E., Zhang, L., Radu, A., Bebbington, M., Liechty, K., Adzick, N., & Flake, A. (2011). Amniotic fluid levels of glial fibrillary acidic protein in fetal rats with retinoic acid induced myelomeningocele: A potential marker for spinal cord injury. American Journal of Obstetrics and Gynecology, 204(2). doi:10.1016/j.ajog.2010.09.032
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  Objective The objective of this study was to determine whether amniotic fluid levels of glial acidic fibrillary protein (GFAP) would reflect myelomeningocele-related neurodegeneration in the rat model of retinoic acidinduced myelomeningocele, which is a model that is very similar to human myelomeningocele and develops the entire spectrum of disease severity including features of the Chiari II malformation. Study Design Time-dated (embryonic day 10) pregnant Sprague-Dawley rats were gavage fed 60 mg/kg/bodyweight retinoic acid that had been dissolved in olive oil or olive oil alone. Myelomeningocele, retinoic acidexposed no myelomeningocele, and control fetuses were harvested at specific time points throughout gestation. A standard set of pinching tests was performed to interrogate the sensorimotor reflex arc of hindpaws and tails. Amniotic fluidGFAP levels were analyzed by standard enzyme-linked immunosorbent assay techniques. Results Amniotic fluidGFAP levels were similar between groups at embryonic days 14, 16, and 18, respectively. Compared with control fetuses, amniotic fluid GFAP levels were significantly increased in myelomeningocele fetuses at embryonic days 20 and 22 (P < .001). Defect size (P < .001), presence of clubfoot deformity (P = .0004), and absence of sensorimotor function (P < .01) at embryonic day 22 correlated with amniotic fluidGFAP levels. Conclusion Amniotic fluidGFAP levels appear to correlate with spinal cord injury as gestation proceeds in fetal rats with myelomeningocele. © 2011 Mosby, Inc.
• Volk, S., Wang, Y., Mauldin, E., Liechty, K., & Adams, S. (2011). Diminished type III collagen promotes myofibroblast differentiation and increases scar deposition in cutaneous wound healing. Cells Tissues Organs, 194(1). doi:10.1159/000322399
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  The repair of cutaneous wounds in the postnatal animal is associated with the development of scar tissue. Directing cell activities to efficiently heal wounds while minimizing the development of scar tissue is a major goal of wound management and the focus of intensive research efforts. Type III collagen (Col3), expressed in early granulation tissue, has been proposed to play a prominent role in cutaneous wound repair, although little is known about its role in this process. To establish the role of Col3 in cutaneous wound repair, we examined the healing of excisional wounds in a previously described murine model of Col3 deficiency. Col3 deficiency (Col3+/-) in aged mice resulted in accelerated wound closure with increased wound contraction. In addition, Col3-deficient mice had increased myofibroblast density in the wound granulation tissue as evidenced by an increased expression of the myofibroblast marker, α-smooth muscle actin. In vitro, dermal fibroblasts obtained from Col3-deficient embryos (Col3+/-and-/-) were more efficient at collagen gel contraction and also displayed increased myofibroblast differentiation compared to those harvested from wild-type (Col3+/+) embryos. Finally, wounds from Col3-deficient mice also had significantly more scar tissue area on day 21 postwounding compared to wild-type mice. The effect of Col3 expression on myofibroblast differentiation and scar formation in this model suggests a previously undefined role for this ECM protein in tissue regeneration and repair. © 2011 S. Karger AG, Basel.
• Grice, E., Snitkin, E., Yockey, L., Bermudez, D., Liechty, K., & Segre, J. (2010). Erratum: Longitudinal shift in diabetic wound microbiota correlates with prolonged skin defense response (Proceedings of the National Academy of Sciences of the United States of America (2010) 107, 33, (14799-14804) DOI: 10.1073/pnas. 1004204107). Proceedings of the National Academy of Sciences of the United States of America, 107(41). doi:10.1073/pnas.1013773107
• Grice, E., Snitkin, E., Yockey, L., Bermudez, D., Liechty, K., & Segre, J. (2010). Longitudinal shift in diabetic wound microbiota correlates with prolonged skin defense response. Proceedings of the National Academy of Sciences of the United States of America, 107(33). doi:10.1073/pnas.1004204107
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  Diabetics frequently suffer from chronic, nonhealing wounds. Although bacterial colonizationand/or infectionaregenerally acknowledged to negatively impact wound healing, the precise relationship between the microbial community and impaired wound healing remains unclear. Because the host cutaneous defense response is proposed to play a key role in modulating microbial colonization, we longitudinally examined the diabetic wound microbiome in tandem with host tissue gene expression. By sequencing 16S ribosomal RNA genes, we show that a longitudinal selective shift in wound microbiota coincides with impaired healing in diabetic mice (Leprdb/db; db/db). We demonstrate a parallel shift in longitudinal gene expression that occurs in a cluster of genes related to the immune response. Further, we establish a correlation between relative abundance of Staphylococcus spp. and the expression of cutaneous defense response genes. Our data demonstrate that integrating two types of global datasets lends a better understanding to the dynamics governing host-microbe interactions.
• Herdrich, B., Danzer, E., Davey, M., Bermudez, D., Radu, A., Zhang, L., Zhang, Z., Soslowsky, L., & Liechty, K. (2010). Fetal tendon wound size modulates wound gene expression and subsequent wound phenotype. Wound Repair and Regeneration, 18(5). doi:10.1111/j.1524-475x.2010.00615.x
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  The fetal response to small tendon injury results in regenerative or scarless healing and is characterized by a markedly diminished cellular inflammatory response, lack of fibroplasia, and restoration of normal tissue architecture. We hypothesized that an increasing fetal tendon wound size would lead to increased wound inflammation and a change from regenerative to reparative healing and scar formation. We created small or large tendon wounds in early gestation fetal sheep and used histology to assess tissue architecture, immunohistochemistry to assess the cellular inflammatory response, ovine-specific gene microarrays, and real-time reverse transcription-polymerase chain reaction to measure the gene expression in response to injury. Small tendon wounds showed a regenerative healing phenotype with orderly deposition of collagen fibers while large tendon wounds showed disorderly collagen deposition consistent with scar formation. Small tendon wounds had few inflammatory cells at 7 and 28 days after injury, whereas the large wounds showed a significant inflammatory cell infiltrate at 7 days that resolved by 28 days. At 3 days, the differential expression of genes involved in the response to injury and inflammation were seen between large and small tendon wounds. By real-time polymerase chain reaction at 7 days, large tendon wounds also had significantly increased expression of interleukin-6, interleukin-8, transforming growth factor-β1, and transforming growth factor-β3, compared with the small wounds. Increasing the fetal tendon wound size results in increased proinflammatory gene expression, inflammatory cell infiltration, and a change from regenerative to reparative healing. This model allows the process of regenerative healing to be examined without the confounding variable of gestational age. © 2010 by the Wound Healing Society.
• Liechty, K. (2010). Ex-utero intrapartum therapy. Seminars in Fetal and Neonatal Medicine, 15(1). doi:10.1016/j.siny.2009.05.007
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  The ex-utero intrapartum therapy (EXIT) procedure was designed to secure the airway at delivery in fetuses who had undergone tracheal occlusion for severe congenital diaphragmatic hernia. The EXIT was then adapted for deliveries where the airway may be difficult to secure, such as large neck masses or congenital high airway obstruction. Subsequently, use of EXIT has been extended to fetal anomalies where resuscitation may be compromised, including large thoracic masses, severe congenital diaphragmatic hernia, or pulmonary agenesis. The key to EXIT is preservation of uteroplacental blood flow and gas exchange, using inhalational agents to provide uterine relaxation, and maintenance of uterine volume by amnioinfusion and only partial exposure of the fetus. This provides time for procedures such as laryngoscopy, bronchoscopy, vascular access, resection of neck or lung masses, or cannulation for extracorporeal membrane circulation, in order to convert an emergent crisis to a controlled situation. © 2009.
• Peranteau, W., Zhang, L., Muvarak, N., Badillo, A., Radu, A., Zoltick, P., & Liechty, K. (2008). IL-10 overexpression decreases inflammatory mediators and promotes regenerative healing in an adult model of scar formation. Journal of Investigative Dermatology, 128(7). doi:10.1038/sj.jid.5701232
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  Adult wound healing is characterized by an exuberant inflammatory response and scar formation. In contrast, scarless fetal wound healing has diminished inflammation, a lack of fibroplasia, and restoration of normal architecture. We have previously shown that fetal wounds produce less inflammatory cytokines, and the absence of IL-10, an anti-inflammatory cytokine, results in fetal scar formation. We hypothesized that increased IL-10 would decrease inflammation and create an environment conducive for regenerative healing in the adult. To test this hypothesis, a lentiviral vector expressing IL-10 and green fluorescent protein (GFP) (Lenti-IL-10) or GFP alone (Lenti-GFP) was injected at the wound site 48 hours before wounding. We found that both Lenti-IL-10 and Lenti-GFP were expressed in the wounds at 1 and 3 days post wounding. At 3 days, Lenti-IL-10-treated wounds demonstrated decreased inflammation and decreased quantities of all proinflammatory mediators analyzed with statistically different levels of IL-6, monocyte chemoattractant protein-1, and heat-shock protein 47. At 3 weeks, Lenti-GFP wounds demonstrated scar formation. In contrast, wounds injected with Lenti-IL-10 demonstrated decreased inflammation, a lack of abnormal collagen deposition, and restoration of normal dermal architecture. We conclude that lentivirus-mediated overexpression of IL-10 decreases the inflammatory response to injury, creating an environment conducive for regenerative adult wound healing. © 2008 The Society for Investigative Dermatology.
• Ricchetti, E., Reddy, S., Ansorge, H., Zgonis, M., Van Kleunen, J., Liechty, K., Soslowsky, L., & Beredjiklian, P. (2008). Effect of Interleukin-10 Overexpression on the Properties of Healing Tendon in a Murine Patellar Tendon Model. Journal of Hand Surgery, 33(10). doi:10.1016/j.jhsa.2008.07.020
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  Purpose: Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine shown to inhibit scar formation in fetal wound healing. The role of IL-10 in adult tendon healing and scar formation, however, remains unknown. The objective of this study is to investigate the effect of IL-10 overexpression on the properties of adult healing tendon using a well-established murine model of tendon injury and a lentiviral-mediated method of IL-10 overexpression. Methods: A murine model of patellar tendon injury was used and animals divided into 3 groups. Mice received bilateral patellar tendon injections with a lentiviral vector containing an IL-10 transgene (n = 34) or no transgene (n = 34). Control mice (n = 34) received injections of sterile saline. All animals then were subjected to bilateral, central patellar tendon injuries 2 days after injection and were killed at 5, 10, 21, and 42 days after injury. IL-10 content was analyzed by immunohistochemistry (n = 4/group). Tendon healing was evaluated by histology (n = 4/group) and biomechanical analysis (n = 10/group). Results: Overexpression of IL-10 in patellar tendon was confirmed after injection of the lentiviral vector. IL-10 immunostaining was increased at day 10 in the IL-10 group relative to that in controls. Histologically, there was no significant difference in angular deviation between groups at day 21, but a trend toward decreased angular deviation in controls relative to that in empty vector group mice was seen at day 42. Biomechanically, the IL-10 group showed significantly increased maximum stress at day 42 relative to that in controls. Percent relaxation showed a trend toward an increase at day 10 and a significant increase at day 42 in the IL-10 group relative to that in controls. Conclusions: This study demonstrates successful gene transfer of IL-10 into adult murine patellar tendon using a lentiviral vector. Although the effects of overexpression of IL-10 on adult tendon healing have not yet been fully elucidated, the current study may help to further clarify the mechanisms of tendon injury and repair. © 2008 American Society for Surgery of the Hand.
• Tsai, A., Liechty, K., Hedrick, H., Bebbington, M., Wilson, R., Johnson, M., Howell, L., Flake, A., & Adzick, N. (2008). Outcomes after postnatal resection of prenatally diagnosed asymptomatic cystic lung lesions. Journal of Pediatric Surgery, 43(3). doi:10.1016/j.jpedsurg.2007.10.032
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  Background: Symptomatic congenital lung lesions require surgical resection, but the management of asymptomatic lung lesions is controversial. Some surgeons advocate observation because of concerns about potential operative morbidity and mortality, as well as a lack of long-term follow-up information. On the other hand, malignant degeneration, pneumonia, and pneumothorax are known consequences of cystic lung lesions. This study aims to assess the safety of resection for asymptomatic lung lesions that were diagnosed before birth. Methods: A retrospective review of all patients with prenatally diagnosed lung lesions at Children's Hospital of Philadelphia (Philadelphia, Penn) was performed from 1996 to 2005. The perioperative course of patients who were asymptomatic was analyzed. Results: One hundred five complete records of children with asymptomatic lesions were reviewed. Overall mortality was 0% and morbidity was 6.7% including 2.9% significant postoperative air leak and 3.8% transfusion requirement. Nine patients had a pathologic diagnosis that differed from preoperative radiological findings, and 9 patients had additional pathologic findings. Conclusion: This series demonstrates that surgery can be performed safely on patients who were asymptomatic with congenital cystic adenomatoid malformation of the lung and other types of lung lesions with no mortality and minimal morbidity. The frequency of disparate pathologic diagnoses and the potential for development of malignancy and other complications support the argument for early resection. © 2008 Elsevier Inc. All rights reserved.
• Badillo, A., Chung, S., Zhang, L., Zoltick, P., & Liechty, K. (2007). Lentiviral Gene Transfer of SDF-1α to Wounds Improves Diabetic Wound Healing. Journal of Surgical Research, 143(1). doi:10.1016/j.jss.2007.03.051
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  Background: Chronic wounds continue to be a major clinical problem and novel therapeutic approaches are needed. We have previously demonstrated that treatment of diabetic mouse wounds with local application of stromal progenitor cells results in improved healing and increased production of stromal-derived growth factor-1α (SDF-1α). We hypothesized that lentiviral-mediated increased production of SDF-1α in the wound environment could also improve diabetic wound healing. Materials and methods: Full-thickness excisional wounds were created in Db-/Db- mice and immediately treated with 106, 108, or 109 plaque-forming units of a lentiviral construct containing GFP-SDF-1α or GFP alone. At 7 and 14 days post wounding, wounds were harvested for histological and molecular analysis. Results: At 7 days, Db-/Db- wounds treated with lenti GFP-SDF-1α exhibited a decrease in wound surface area for all doses tested. Morphologically, SDF-treated wounds were more cellular with increased granulation tissue volume compared to controls (P < 0.05). GFP expression was maintained in treated tissue at 7 days post wounding, but little expression was observed at 14 days. While we did not observe a difference in the gross wound surface area at 14 days, histological analysis revealed that SDF-treated wounds were fully epithelialized (n = 6) compared to only one of six controls. Conclusions: Lentiviral-mediated overproduction of SDF-1α is sufficient to correct the pathophysiologic abnormalities in diabetic wound healing resulting in complete epithelialization at 2 weeks. SDF-1α-mediated improvement in diabetic wound healing has significant implications for the development of novel therapeutic strategies to facilitate wound closure which target progenitor cell mobilization and recruitment. © 2007 Elsevier Inc. All rights reserved.
• Hedrick, H., Danzer, E., Merchant, A., Bebbington, M., Zhao, H., Flake, A., Johnson, M., Liechty, K., Howell, L., Wilson, R., & Adzick, N. (2007). Liver position and lung-to-head ratio for prediction of extracorporeal membrane oxygenation and survival in isolated left congenital diaphragmatic hernia. American Journal of Obstetrics and Gynecology, 197(4). doi:10.1016/j.ajog.2007.07.001
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  Objective: The purpose of this study was to determine the ability of liver position and lung-to-head ratio to predict outcome in isolated left congenital diaphragmatic hernia. Study Design: We reviewed prenatal studies and postnatal outcomes of congenital diaphragmatic hernia between January 1996 and January 2006. Results: Eighty-nine patients received prenatal and postnatal care at 1 institution. In fetuses with liver up, extracorporeal membrane oxygenation was required in 39 of 49 fetuses (80%), compared with 10 of 40 fetuses (25%) for those with liver down (P < .0001). Overall survival rate was 45%, compared with 93% for those with liver down (P < .00005). Low lung-to-head ratio (
• Peranteau, W., Wilson, R., Liechty, K., Johnson, M., Bebbington, M., Hedrick, H., Flake, A., & Adzick, N. (2007). Effect of maternal betamethasone administration on prenatal congenital cystic adenomatoid malformation growth and fetal survival. Fetal Diagnosis and Therapy, 22(5). doi:10.1159/000103298
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  Objective: To evaluate the effect of prenatal steroid treatment on the growth of congenital cystic adenomatoid malformations (CCAM) and survival in affected fetuses not amenable to other percutaneous ultrasound-guided prenatal interventions. Methods: A retrospective review of patients with a CCAM or hybrid lesion treated with two maternal prenatal betamethasone injections was performed. Patients receiving cyst aspiration or thoracoamniotic shunting at the time of or after steroid administration were excluded. Growth rates and survival data were compared to historical non-steroid treated controls. Results: Eleven patients were treated with prenatal steroids (10 microcystic and 1 macrocystic). Survival was 100% in fetuses with hydrops (5/5) or a CCAM volume ratio (CVR) >1.6 (7/7) at the time of steroid administration. This compares to a mortality of 100 and 56.2% respectively in historical non-treated controls. Resolution of hydrops was seen in 80% (4/5) of steroid-treated patients. CCAM growth rates were variable after steroid administration. However, when compared to historical data where CVR and CCAM volume have been documented to increase until 28 weeks' gestation, the CVR and CCAM volume growth rates decreased in 72.73% and 50% of patients respectively from the time of steroid administration to 28 weeks' gestation. Conclusions: In the fetus with a CCAM, the presence of hydrops fetalis or a CVR >1.6 is indicative of poor fetal outcome without prenatal intervention. The observed effect of antenatal steroid treatment on CCAM growth is variable, but its potential to improve survival in these high-risk groups is encouraging and warrants further controlled evaluations. Copyright © 2007 S. Karger AG.
• Davenport, M., Crombleholme, T., Hedrick, H., Howell, L., Johnson, M., Coleman, B., Liechty, K., Flake, A., & Adzick, N. (2002). Letter to the editor (multiple letters). Journal of Pediatric Surgery, 37(12). doi:10.1053/jpsu.2002.36723
• Liechty, K., Adzick, N., & Crombleholme, T. (2000). Diminished interleukin 6 (IL-6) production during scarless human fetal wound repair. Cytokine, 12(6). doi:10.1006/cyto.1999.0598
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  Fetal wound healing is characterized by minimal inflammation and scarless repair. IL-6 stimulates inflammation in postnatal wound healing. We hypothesized that fetal skin has a diminished IL-6 response and that exogenous IL-6 will result in scar formation. Human adult or fetal skin was placed subcutaneously in SCID mice and incisionally wounded. Wounds were excised after 4, 12, 24 or 72 h for IL-6 mRNA quantification by RT-PCR. In other grafts, 5 μg of IL-6 was injected at wounding and then harvested at 7 days for analysis of scar formation. IL-6 production was examined in primary cultures of human fetal or adult dermal fibroblasts incubated for 8 h with 0, 0.1, 1 or 10 ng/ml of PDGF-BB. IL-6 mRNA was detected 4 h after wounding in fetal and adult wounds, but by 12 h there was no IL-6 mRNA in the fetal wounds. Adult wounds had IL-6 mRNA persisting to 72 h. IL-6 administration to fetal wounds resulted in scar formation. Fetal fibroblasts produced less IL-6 protein and mRNA at all points examined (P < 0.01 vs adult). Diminished production of inflammatory cytokines such as IL-6 may be responsible for the lack of inflammation seen during fetal wound healing. Diminished inflammation may provide a permissive environment for scarless wound healing. (C) 2000 Academic Press.
• Liechty, K., Mackenzie, T., Shaaban, A., Radu, A., Moseley, A., Deans, R., Marshak, D., & Flake, A. (2000). Human mesenchymal stem cells engraft and demonstrate site-specific differentiation after in utero transplantation in sheep. Nature Medicine, 6(11). doi:10.1038/81395
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  Mesenchymal stem cells are multipotent cells that can be isolated from adult bone marrow and can be induced in vitro and in vivo to differentiate into a variety of mesenchymal tissues, including bone, cartilage, tendon, fat, bone marrow stroma, and muscle. Despite their potential clinical utility for cellular and gene therapy, the fate of mesenchymal stem cells after systemic administration is mostly unknown. To address this, we transplanted a well-characterized human mesenchymal stem cell population into fetal sheep early in gestation, before and after the expected development of immunologic competence. In this xenogeneic system, human mesenchymal stem cells engrafted and persisted in multiple tissues for as long as 13 months after transplantation. Transplanted human cells underwent site-specific differentiation into chondrocytes, adipocytes, myocytes and cardiomyocytes, bone marrow stromal cells and thymic stroma. Unexpectedly, there was long-term engraftment even when cells were transplanted after the expected development of immunocompetence. Thus, mesenchymal stem cells maintain their multipotential capacity after transplantation, and seem to have unique immunologic characteristics that allow persistence in a xenogeneic environment. Our data support the possibility of the transplantability of mesenchymal stem cells and their potential utility in tissue engineering, and cellular and gene therapy applications.
• Liechty, K., & Crombleholme, T. (1999). Management of fetal airway obstruction. Seminars in Perinatology, 23(6). doi:10.1016/s0146-0005(99)80028-7
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  Fetal airway obstruction can make it difficult if not impossible to secure the airway at birth, before hypoxia, brain injury, or death results. Fetal airway obstruction can result from an intrinsic defect in the airway, such as the congenital high airway obstruction syndrome or extrinsic compression of the airway caused by a cervical mass, most commonly a cervical teratoma or lymphangioma. As fetuses with fetal airway obstruction reach viability, they should be monitored closely for the development or progression of hydrops in intrinsic obstruction cases or polyhydramnios in extrinsic obstruction cases. The fetus should be delivered by using the ex utero intrapartum treatment procedure, with maintenance of uteroplacental circulation and gas exchange. This approach provides time to perform procedures such as direct laryngoscopy, bronchoscopy, or tracheostomy to secure the fetal airway, thereby converting an emergent airway crisis into a controlled situation.
• Liechty, K., Nesbit, M., Herlyn, M., Radu, A., Scott Adzick, N., & Crombleholme, T. (1999). Adenoviral-mediated overexpression of platelet-derived growth factor-b corrects ischemic impaired wound healing. Journal of Investigative Dermatology, 113(3). doi:10.1046/j.1523-1747.1999.00705.x
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  Chronic wounds represent a major clinical problem with significant morbidity and healthcare expenditures, but no effective therapies. Topical platelet-derived growth factor-BB trials have required large and repeated doses to achieve only a modest effect. We examined the ability of an adenovirus containing the platelet-derived growth factor-B transgene to improve the rate of wound healing through induction of platelet-derived growth factor-B overexpression in cells participating in the wound healing response. We treated excisional wounds in the ischemic rabbit ear, which have a 60% delay in healing, with vehicle, 106, or 108 plaque-forming units of an adenovirus containing the platelet-derived growth factor-B per wound (n = 19). At 7 d this resulted in a decrease in the epithelial gap from 3.4 ± 1 mm (mean ± SD) in vehicle-treated wounds to 1.9 ± 1.8 mm (mean ± SD, p < 0.05) when treated with 106 plaque-forming units of an adenovirus containing the platelet-derived growth factor-B, and 0.7 ± 1.1 mm (mean ± SD, p < 0.001) when treated with 108 plaque-forming units of an adenovirus containing the platelet-derived growth factor-B. Ischemic excisional wounds treated with 108 plaque-forming units of an adenovirus containing the platelet-derived growth factor-B even healed more rapidly than non-ischemic excisional wounds treated with vehicle (p < 0.05). In contrast, 5 μg of platelet-derived growth factor-BB protein (n = 2) resulted in only modest granulation tissue at the margin, but no significant differences in epithelial gap (3 ± 0.6 mm, mean ± SD). Plaque-forming units (106 or 108) of an adenovirus containing the β-galactosidase transgene (n = 4) impaired wound re-epithelialization with an epithelial gap of 5.11 ± 0.69 mm, mean ± SD, p < 0.004, and 3.8 ± 0.57 mm, mean ± SD, p < 0.07, respectively. Adenoviral-mediated gene transfer of platelet-derived growth factor-B overcame the ischemic defect in wound healing and offers promise in the treatment of chronic nonhealing wounds. The vulnerary effects of platelet- derived growth factor-B overexpression were sufficient to overcome the adverse effects of the adenovirus or transgene on wound healing.
• Kim, H., Shaaban, A., Yang, E., Liechty, K., & Flake, A. (1998). Microchimerism and tolerance after in utero bone marrow transplantation in mice. Journal of Surgical Research, 77(1). doi:10.1006/jsre.1997.5255
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  Background. Donor-specific tolerance has been induced after both fetal and neonatal hematopoietic stem cell (HSC) transplantation in mice. However, the relationship between hematopoietic microchimerism and tolerance in these models has not been defined due to the insensitivity of donor cell detection methodology. To address this problem we developed a semi-quantitative polymerase chain reaction (PCR)-based assay for detection of microchimerism after major histocompatibility (MHC) class I disparate HSC transplantation. This assay was used to examine the relationship between microchimerism and tolerance after fetal and neonatal transplantation of fully allogeneic bone marrow cells. Materials and methods. C57BL/6 mice (H2-Kb) were used as adult bone marrow donors and Balb/c mice (H2-Kd) were used as fetal or newborn recipients. A dose of 1010 BM cells/kg was injected intraperitoneally into recipient animals. Peripheral blood of animals which survived beyond 3 weeks of age was analyzed by PCR for the presence of donor MHC class I DNA. Tolerance was tested by placement of donor-specific skin grafts after determination of chimerism status. Results. Our assay was found to be specific for H2Kb donor cells in an H2-Kd background with a sensitivity of
• Liechty, K., Crombleholme, T., Cass, D., Martin, B., & Adzick, N. (1998). Diminished interleukin-8 (IL-8) production in the fetal wound healing response. Journal of Surgical Research, 77(1). doi:10.1006/jsre.1998.5345
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  Background. Fetal skin wound healing results in scarless repair with minimal cellular inflammatory response. Interleukin-8 (IL-8) stimulates inflammation in postnatal wound healing but little is known about its role in fetal wounds. We hypothesized that fetal tissues have diminished IL-8 during wound repair and in response to platelet-derived growth factor (PDGF), a growth factor central to wound healing. Materials and methods. To examine the IL-8 response of fibroblasts to PDGF, cultures of human fetal (17-18 weeks) and adult dermal fibroblasts were incubated 8 h with PDGF (0, 0.1, 1, or 10 ng/mL) and supernatants and cells were collected for IL-8 ELISA and IL8 RT- PCR. To evaluate the IL-8 response to wounding, human adult and fetal skin was placed subcutaneously in the SCID mouse, wounded, and the wound cleft excised after 4, 12, 24, or 72 h for IL-8 RT-PCR. Results. Fetal fibroblasts produced less IL-8 protein at baseline (50 ± 6 pg/mL versus 450 ± 115 pg/mL, P < 0.001) and in response to all concentrations of PDGF examined (P < 0.001). IL-8 mRNA was detected in unstimulated adult fibroblasts but not in fetal fibroblasts. Much less IL-8 mRNA was detected in stimulated fetal fibroblasts than in adult fibroblasts. IL-8 mRNA was detected 4 h after wounding in fetal and adult wounds. By 12 h no IL-8 mRNA was detected in fetal wounds, whereas adult wounds had IL-8 mRNA persisting to 72 h. Conclusions. Diminished inflammatory cytokine response by fetal tissues may be responsible for the lack of cellular recruitment and inflammation seen in fetal wound healing and may contribute to scarless wound repair.
• Liechty, K., Crombleholme, T., Flake, A., Morgan, M., Kurth, C., Hubbard, A., & Adzick, N. (1997). Intrapartum airway management for giant fetal neck masses: The EXIT (ex utero intrapartum treatment) procedure. American Journal of Obstetrics and Gynecology, 177(4). doi:10.1016/s0002-9378(97)70285-0
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  OBJECTIVE: Our goal was to review our experience with the EXIT (ex utero intrapartum treatment) procedure in the management of five cases with re- threatening fetal neck masses. STUDY DESIGN: We present a retrospective review of prenatal presentation and course, diagnostic accuracy of imaging studies, intraoperative management, complications, and outcomes. RESULTS: Polyhydramnios was the initial presenting symptom in three of five fetuses with a mean gestational age of 25 ± 6 weeks. Preterm labor occurred in two patients. Fetal magnetic resonance imaging provided accurate diagnosis in all four cases whereas conventional ultrasonography led to the diagnosis in four of five cases. The mean duration of EXIT was 28 ± 22 minutes. The mean venous core blood gas values were pH 7.22 ± 0.05, PCO2 61 ± 11 mm Hg, and PO2 42 ± 8 mm Hg. In four of five oases an airway was successfully secured. CONCLUSIONS: The EXIT procedure provides up to 1 hour of good uteroplacental support and is the procedure of choice to secure an airway in the fetus with a giant neck mass.
• Schibler, K., Li, Y., Ohls, R., Nye, N., Durham, M., White, W., Liechty, K., Le, T., & Christensen, R. (1994). Possible mechanisms accounting for the growth factor independence of hematopoietic progenitors from umbilical cord blood. Blood, 84(11). doi:10.1182/blood.v84.11.3679.bloodjournal84113679
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  Hematopoietic progenitors obtained from the bone marrow of healthy adults fail to undergo clonogenic maturation in vitro if a source of hematopoietic growth factors is not included in the culture dishes. In contrast, a fraction of similarly purified progenitors obtained from umbilical cord blood undergo clonogenic maturation even in the absence of added growth factors. We postulated that production of hematopoietic growth factors within the culture dishes containing the progenitors of umbilical cord blood origin might be responsible. We postulated further, that this production might be by non- progenitor cells co-plated along with the progenitors, or alternatively by CD34+ cells themselves, or by cells clonally derived from CD34+ cells. To test these possibilities we first assessed the effect of including in the cultures neutralizing antibody directed against various growth factors. Inclusion of anti-granulocyte macrophage colony-stimulating factor (GM-CSF) and anti-interleukin-3 (IL-3) (but not anti-IL-2) significantly reduced the growth factor independence of cord blood progenitors (P < .005 and P < .01). Inclusion of both anti-GM-CSF and anti-IL-3 almost completely ablated the spontaneous colony growth (P < .001). Inclusion of IL-10 also reduced, in a concentration-dependent fashion, the spontaneous generation of umbilical cord blood-derived colonies. Transcripts for GM-CSF and IL-3 were detected, by reverse transcriptase-polymerase chain reaction (RT-PCR), in the CD34+ cells from cord blood and from adult marrow. When plated without added growth factors, however, the CD34- cells of adult marrow origin failed to produce colonies, whereas 6% of cord blood CD34+ cells similarly cultured did so. When these growth factor independent colonies were plucked from culture, transcripts for GM-CSF and IL-3 were identified in all. We conclude that production of GM-CSF and IL-3 occurs within culture dishes containing hematopoietic progenitors of umbilical cord origin, and that this explains some of their apparently unique features of in vitro growth.
• Schibler, K., Ohls, R., Le, T., Liechty, K., & Christensen, R. (1994). Effect of recombinant stem cell factor on clonogenic maturation and cycle status of human fetal hematopoietic progenitors. Pediatric Research, 35(3). doi:10.1203/00006450-199403000-00004
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  Studies were undertaken to delineate the actions of stem cell factor (SCF) on human fetal hematopoietic progenitors in vitro. Mononuclear cells from umbilical cord blood of term fetuses were “panned” immunologically, and the resulting hematopoietic progenitors were grown in methylcellulose culture containing various concentrations of SCF alone or in combination with other recombinant hematopoietic growth factors. Neutralizing antibodies to IL-3 and granulocyte-macrophage colony-stimulating factor were added to all plates to which recombinant IL-3 or granulocyte-macrophage colony-stimulating factor were not included to decrease any confounding effect resulting from production of small quantities of these factors within the culture plates. SCF, as a single agent, supported clonogenic maturation of fetal granulocyte-macrophage progenitors (granulocyte-macrophage colony-forming unit, p < 0.05), multipotent progenitors (CFU-MIX,p < 0.05), and erythroid progenitors (erythroid burst-forming unit, p < 0.05). When combined with subplateau concentrations (0.1 µg/L) of IL-3 or granulocyte-macrophage colony-stimulating factor, SCF had an additive or synergistic effect on clonogenic maturation of granulocyte-macrophage colony-forming unit and CFU-MIX. When combined with higher concentrations (5.0 µg/L) of IL-3 or granulocyte-macrophage colony-stimulating factor, SCF generally did not enhance colony formation but did increase the number of cells per colony. Like other pleiotropic cytokines such as IL-6, IL-9, and IL-11, SCF had a broad spectrum of action of fetal hematopoietic progenitors. © 1994 International Pediatric Research Foundation, Inc.
• Schibler, K., Trautman, M., Liechty, K., White, W., Rothstein, G., & Christensen, R. (1993). Diminished transcription of interleukin-8 by monocytes from preterm neonates. Journal of Leukocyte Biology, 53(4). doi:10.1002/jlb.53.4.399
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  Developmental delays, which impair antibacterial host defense, are present in the neutrophil system of human preterm neonates. We hypothesized that diminished production of interleukin-8 (IL-8), a neutrophil chemotactic peptide, might in part be responsible for these defects. To test this, monocytes from the blood of preterm neonates, term neonates, and adults were isolated immunologically by 'negative panning' and subsequently stimulated with interleukin-1α (IL-1α), tumor necrosis factor α (TNF-α), or lipopolysaccharide (LPS), after which IL-8 levels in the supernatants were measured by ELISA. Total cellular RNA was extracted and IL-8 mRNA was assessed by Northern blotting and by competitive polymerase chain reaction (PCR) analyses. After stimulation with IL-1α, intermediate in supernatants of monocytes from term neonates and greatest from monocytes of adults. Similarly, when stimulated with TNF-α or LPS, monocytes from preterm neonates produced less IL-8 than cells from term neonates and adults. These differences in IL-8 concentrations paralleled differences in IL-8 mRNA expression.
• Schibler, K., Liechty, K., White, W., Rothstein, G., & Christensen, R. (1992). Defective production of interleukin-6 by monocytes: A possible mechanism underlying several host defense deficiencies of neonates. Pediatric Research, 31(1). doi:10.1203/00006450-199201000-00003
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  Several deficiencies in antibacterial defense have been described in neonates. Among those best characterized are delayed maturation of B cells into antibody producing cells, deficient T-cell maturation, and delayed cycling of hematopoietic progenitor cells after an infectious challenge. No unifying theory has been forwarded, however, to explain the concomitance of these three developmental deficiencies. IL-6, a cytokine produced primarily by monocytes and macrophages in response to stimulation by IL-1, is involved in the regulation of these three processes. Thus, we postulated that defective production of IL-6 could be a mechanism underlying these immune deficiencies of neonates. Indeed, we observed that at peak production, cells of five term neonates produced only one half as much IL-6 (14 120 ± 2590 pg IL-6/106 monocytes) as those of five adults (28 940 ± 1680 pg, p < 0.001). Peak production was lower still by monocytes of six preterm neonates (7190 ± 1400 pg, p < 0.001 versus term). Production of IL-6 protein was inhibited by actinomycin D and the IL-6 mRNA content of monocytes from neonates, as assessed by competitive polymerase chain reaction, was less than that of adult monocytes. We speculate that defective IL-6 transcription might underlie some of the defects in immune regulation observed in neonates. © 1991 International Pediatric Research Foundation, Inc.
• Christensen, R., Liechty, K., Koenig, J., Schibler, K., & Ohls, R. (1991). Administration of erythropoietin to newborn rats results in diminished neutrophil production. Blood, 78(5).
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  Very high concentrations of erythropoietin (epo), in clonogenic cultures, result in reduced production of neutrophils, and fetal progenitors are more sensitive to this effect of epo than are those of adults. However, the significance of this observation is unclear because no evidence of reduced neutrophil production has been presented following administration of recombinant epo to human or animal subjects. In the present study we injected newborn rats, beginning on the first day of life, with 20, 200, or 2,000 U epo/kg body weight, and measured serum epo concentrations after 2, 8, 24, or 48 hours. After selecting a dose that resulted in serum concentrations greater than 1,000 mU/mL (a concentration that resulted in down-modulation of neutrophil production from neonatal rat progenitors in vitro) other newborn rats were treated for 3 days with that dose (1,000 U epo/kg) or a vehicle control. Administration of epo resulted in increased hematocrits (P
• Gardner, J., Liechty, K., & Christensen, R. (1990). Effects of interleukin-6 on fetal hematopoietic progenitors. Blood, 75(11).
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  Effects of interleukin-6 (IL-6) on cycling status and clonogenic maturation of human fetal (cord blood) and adult hematopoietic progenitors were compared. Adult marrow cells were incubated for various lengths of time with various concentrations of IL-6, in a serum-free system, after which tritiated thymidine suicide studies were performed. After incubation of 2 to 5 ×106 cells/mL for 4 hours in 5.0 ng IL-6/mL, increased thymidine suicide rates were observed for multipotent progenitors (CPU-Mix), granulocyte-macrophage progenitors (CFU-GM), and erythroid burst-forming units (BFU-E). Similar incubations of fetal cells in IL-6 resulted in similar increases in tritiated thymidine suicide rates. In other studies, IL-6 used alone did not support colony formation from adult progenitors. However, it did support colony formation from fetal CFU-Mix (P < .05). CFU-GM (P < .001). and BFU-E (P < .05). In cultures of adult progenitors, IL-6 acted synergistically with IL-3 to support CFU-Mix colony formation (P < .001), but synergistic actions on CFU-GM and BFU-E were not seen. In contrast, IL-6 acted synergistically with IL-3 and with GM-CSF to support colony formation by fetal CFU-Mix, CFU-GM. and BFU-E. Thus, IL-6 appears to have a wider spectrum of action on fetal progenitors from cord blood than on adult progenitors; including not only the induction of cycling, but also the support of clonogenic maturation of CFU-Mix, CFU-GM. and BFU-E. © 1990 by The American Society of Homatology.
• Liechty, K., & Christensen, R. (1990). In Vivo effect of interleukin-6 on cycling status of hematopoietic progenitors from adults and neonates. Pediatric Research, 28(4). doi:10.1203/00006450-199010000-00004
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  In vitro, IL-6 can induce hematopoietic progenitors to progress from G0 into cycle, but a role for IL-6 in regulating cycling status of progenitors in vivo has not been established. In our studies, groups of five to six adult and newborn rats received i.v. injections of either IL-6 (1 ng/g body wt) or the vehicle (control), after which cycling of hematopoietic progenitors was evaluated by tritiated thymidine suicide. Progenitors from adult rats injected with the control had thymidine suicide rates of 7 ± 1% (mean ± SEM), compared with 23 ± 7% in the IL-6 recipients (p < 0.02). Progenitors from newborn rats injected with the control had thymidine suicide rates of 19 ± 2%, compared with 29 ± 1% in the IL-6 recipients 0.003). In addition, IL-6 administration resulted in release of cells from the neutrophil storage pool into the circulation, as evidenced by fewer polymorphonuclear cells flushed from the long bones (neonates, p < 0.001; adults, p < 0.003), a rise in blood neutrophil concentration (neonates, p < 0.001; adults, p < 0.05), and a leukocyte “left shift” (neonates, p < 0.001; adults, p < 0.01). Thus, the effects of IL-6 in vivo in newborn and adult rats include cycle induction of hematopoietic progenitors and release of neutrophils from the storage pool into the circulation. © 1990 International Pediatric Research Foundation, Inc.
• Ohls, R., Liechty, K., Turner, M., Kimura, R., & Christensen, R. (1990). Erythroid "burst promoting" activity in serum of patients with the anemia of prematurity. The Journal of Pediatrics, 116(5). doi:10.1016/s0022-3476(05)82672-1

Proceedings Publications

• Sener, G., Newsom, J., Hilton, S. A., Zgheib, C., Singh, S., Seal, S., Liechty, K. W., & Krebs, M. D. (2019). Self-healable and sustained release zwitterionic cryogels for wound healing. In 42nd Society for Biomaterials Annual Meeting and Exposition 2019: The Pinnacle of Biomaterials Innovation and Excellence, 40.
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  Statement of Purpose: Scar formation, or fibrosis, is a fundamental complication of an extremely wide variety of conditions and disease processes that results in significant healthcare expenditure and morbidity.1,2 Here, we report a method to prepare self-healable zwitterionic cryogels for sustained release of therapeutic miRNA-loaded cerium oxide nanoparticles for wound healing. Recently, we showed that crosslinked poly(SBMA) zwitterionic cryogels have good protein loading and release properties.3 However, these gels are highly crosslinked, resulting in mechanically tough and brittle gels, which may not be suitable for wound dressing applications. An ideal wound dressing material should be flexible and self-healable to resist crack formation due to mechanical stress generated during wound healing.4 Here, we developed a method to prepare zwitterionic cryogels in the absence of any crosslinkers. The prepared cryogels were flexible, injectable, and self-healable, with sustained nanoparticle release. The promise of the developed materials in wound healing applications was demonstrated in a mouse model.
• Connizzo, B., Liechty, K., & Soslowsky, L. (2012). Altered mechanical properties and fiber re-alignment in diabetic mouse supraspinatus and achilles tendons. In ASME 2012 Summer Bioengineering Conference, SBC 2012.
• Crombleholme, T., Coleman, B., Hedrick, H., Liechty, K., Howell, L., Flake, A., Johnson, M., & Adzick, N. (2002). Cystic adenomatoid malformation volume ratio predicts outcome in prenatally diagnosed cystic adenomatoid malformation of the lung. In N/A, 37.
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  Background/Purpose: Cystic adenomatoid malformation of the lung (CAM) diagnosed in utero has a variable natural history that may result in hydrops in up to 40% or regress in up to 15%. No criteria have been available to determine which lesions would grow and develop hydrops versus those whose growth would stabilize or regress. To better understand the natural history of CAM the authors developed a measure of tumor volume normalized for gestation age, the CAM volume ratio, or CVR. The results of an initial retrospective review of CVR at presentation suggested its usefulness as a predictor of outcome in CAM. The authors now report the results of prospective use of the CVR both to track tumor growth and regression during gestation and confirm its predictive value in fetuses with CAM. Methods: In the retrospective review performed between November 1998 and August 1999, 32 fetuses with CAM were reviewed and divided into those with hydrops and those in whom hydrops never developed. The CVR was determined by measuring 3 dimensions of the CAM using the formula for the volume of an ellipse and dividing by the head circumference to correct for differences in gestational age. Of the 32 fetuses in the retrospective study, the 8 that had hydrops had a significantly higher CVR (3.1 ± 1.1) compared with hydropic fetuses (0.74 ± 0.48; P < .001). The mean of the nonhydropic fetus's CVR plus 2 standard deviations (0.74 + 0.96 = 1.7) was used as a cutoff in the subsequent prospective study. From September 1, 1999 through March 1, 2001, the authors evaluated prospectively 58 patients with CAM by CVR measurement. These patients were followed up with serial ultrasound scans, and CVR at presentation correlated with the development of hydrops, survival, need for fetal intervention, and the need for ventilatory support or extracorporeal membrane oxygenation (ECMO), and length of hospital stay postnatally. The indication for fetal intervention was the development of hydops. Results: The fetuses with CVR ≤ 1.6 (n = 42) were considered to be at low risk for the development of hydrops, and those with CVR greater than 1.6 (n = 16) were considered at increased risk for developing hydrops. Of the 42 fetuses in the low-risk group, 7 (16.7%) developed hydrops, and all but 1 had a dominant cyst. If CAMs with a dominant cyst are excluded, only 1 of 36 (2.8%) of CAMs with CVR ≤ 1.6 developed hydrops (P < .001). In fetuses with CVR at presentation more than 1.6, 12 of 16 (75%; P < .005) developed hydrops. Seventeen fetuses underwent fetal treatment (8 CVR ≤ 1.6; 9 CVR > 1.6): 7 patients required open fetal surgery (survival rate, 2 of 7), 6 patients thoracoamniotic shunting (survival rate, 6 of 6); and 4 patients cyst aspiration (survival rate, 4 of 4). All survivors of fetal intervention required at a least brief period of ventilatory support; none required ECMO. Conclusions: A CVR of greater than 1.6 at presentation accurately predicts increased risk of hydrops developing in CAM. A CVR of ≤ 1.6 at presentation suggests that the risk of hydrops developing in the absence of a dominant cyst is less than 3%. The CVR is a useful sonographic indicator of fetuses at risk for hydrops who require close ultrasound observation and possible fetal intervention. Copyright © 2002 by W.B. Saunders Company.
• Liechty, K., Kim, H., Adzick, N., & Crombleholme, T. (2000). Fetal wound repair results in scar formation in interleukin-10-deficient mice in a syngeneic murine model of scarless fetal wound repair. In NA, 35.
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  Background: Fetal dermal wound healing is characterized by minimal inflammation, restoration of normal dermal architecture, and scarless repair. The authors have shown that proinflammatory cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8) are diminished during fetal wound repair. Interleukin-10 (IL-10) is an antiinflammatory cytokine that decreases production of IL-6 and IL-8. The authors hypothesized that diminished IL-6 and IL-8 and minimal inflammation may be caused by IL-10. Methods: To test this hypothesis, the authors developed a new syngeneic murine model of fetal wound repair in which 15-day-gestation skin from either normal C57BL/6 or transgenic C57BL/6 IL-10 knockout mice was grafted to the back of the same strain adult mice. The grafts were incisionally wounded after 5 days, harvested at 1 week, and analyzed for inflammatory response and scar formation. Results: Wounds in normal fetal skin grafts showed minimal inflammation and normal dermal reticular collagen pattern at the site of the wound, consistent with scarless repair. In contrast, wounds in IL-10 knockout fetal skin grafts showed significant inflammation and scar formation. Conclusions: Fetal skin grafts on adult syngeneic mice heal without inflammation or scar formation. The absence of IL-10 in fetal skin results in scar formation. Intrinsic lack of IL-10 may result in continued amplification of the inflammatory cytokine cascade, continued stimulation of fibroblasts, and abnormal collagen deposition. IL-10 is necessary for scarless wound repair to occur. Copyright (C) 2000 by W.B. Saunders Company.
• Liechty, K., Crombleholme, T., Quinn, T., Cass, D., Flake, A., & Adzick, N. (1999). Elevated platelet-derived growth factor-B in congenital cystic adenomatoid malformations requiring fetal resection. In NA, 34.
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  Background: During lung development, platelet-derived growth factor-BB (PDGF-BB) is maximal during the canalicular stage and decreases by the saccular stage. PDGF-BB stimulates lung growth by increasing cell proliferation. Fetal CCAMs have been shown to have an elevated proliferative index, but it is not known why some CCAMs rapidly enlarge in utero and cause fetal hydrops. The authors hypothesized that the high proliferative index and rapid enlargement of some fetal CCAMs may be caused by persistently elevated PDGF-BB production compared with normal fetal lung. Methods: To test this hypothesis, tissue was obtained at the time of resection from two fetal CCAMs (22 weeks), three full-term CCAMs, and three normal fetal lungs (21 to 22 weeks). PDGF-BB production by fetal CCAMs was compared with normal age- matched fetal lung using immunohistochemistry, reverse transcriptionase- polymerase chain reaction (RTPCR), and Western blot analysis. Results: CCAMs resulting in fetal hydrops and requiring fetal resection had strong mesenchymal immunostaining for PDGF-BB next to epithelial lined cysts, increased PDGF-B gene expression by RT-PCR, and elevated PDGF-BB protein by Western blot, compared with normal age-matched fetal lung. Term CCAMs had minimal PDGF-BB staining, PDGF-B gene expression, and PDGF-BB protein production. Conclusions: CCAMs that grew rapidly and progressed to hydrops, requiring in utero resection, demonstrated increased mesenchymal PDGF-B gene expression and PDGF-BB protein production compared with age-matched normal fetal lung, which may, in part, be responsible for the autonomous growth and proliferation seen in hydropic fetal CCAMs.
• Quinn, T., Sylvester, K., Kitano, Y., Kitano, Y., Liechty, K., Jarrett, B., Adzick, N., & Flake, A. (1999). TGF-β2 is increased after fetal tracheal occlusion. In NA, 34.
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  Background/Purpose: Fetal tracheal occlusion (TO) accelerates lung growth in normal and hypoplastic fetal lung. The mechanism of accelerated lung growth remains unknown but may be a result of growth factor induction. Previous studies of growth factors induced by tracheal ligation have characterized mRNA rather than protein expression. Although the transforming growth factor-β (TGF-β) family participates in normal lung morphogenesis, its role in lung growth after TO is unclear. The authors hypothesize that TGF-β expression is increased with TO and may contribute to the accelerated lung growth seen after TO. Methods: Diaphragmatic hernia (DH) was created in 80-day-gestation sheep (n = 6; term, 145) by excising the left diaphragm. At 110 days, the trachea was occluded (n = 4) with a clip. DH controls (n = 2) were not occluded. Fetuses were killed at 139 days, and lung samples were snap frozen for tissue analysis. Non-DH control lungs were harvested from full-term animals (n = 2). TGF-β mRNA was analyzed by semiquantitative reverse transcriptionase-polymerase chain reaction (RT-PCR). TGF-β protein was assessed by Western blot analysis. Results: TGF-β1 mRNA and protein were not increased with tracheal ligation compared with either non-DH or DH controls. TGF-β2, however, was markedly increased, at both the mRNA and protein level, in ligated lungs compared with nonligated controls. Conclusions: TGF-β2 protein, but not TGF-β1, is increased in the hypoplastic lungs of fetal sheep after tracheal occlusion. Increased TGF-β2 expression appears to result from increased or prolonged expression of mRNA transcripts. This is the first study to document a change in growth factor protein levels after TO. Increased TGF-β2 expression may contribute to accelerated lung growth and decreased surfactant production observed after tracheal occlusion.
• Cass, D., Quinn, T., Yang, E., Liechty, K., Crombleholme, T., Flake, A., & Adzick, N. (1998). Increased cell proliferation and decreased apoptosis characterize congenital cystic adenomatoid malformation of the lung. In NA, 33.
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  Background/Purpose: Congenital cystic adenomatoid malformations (CCAM) are lung lesions that demonstrate abnormalities of both mesenchymal and epithelial tissues. The pathogenesis of these tumors remains unknown. Because normal organogenesis requires a balance between cell proliferation and programmed cell death (apoptosis), the authors hypothesized that CCAM results from an increase in cell proliferation or a decrease in apoptosis within the developing lung, possibly mediated by keratinocyte growth factor (KGF). Methods: To examine cell cycle control in CCAM, we measured indices of cell proliferation and apoptosis in lesions requiring fetal (n = 4) or neonatal (n = 8) resection compared with those of normal fetal (14 to 28 weeks' gestation; n = 14) and neonatal (n = 3) human lung. Cell proliferation was analyzed by immunostaining for a proliferation marker (Ki67). Apoptosis was examined using an in situ digoxigenin end-labeling technique to localize apoptotic bodies. The expression of KGF protein and KGF mRNA in CCAM and normal lung was examined using immunohistochemistry and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Results: CCAM lesions in general showed a twofold increase in Cell proliferation index (19.2% ± 1.4% v 9,6% ± 0.7%, P < .00005) and a fivefold decrease in apoptotic bodies (0.9 ± 0.2 v 4.5 ± 0.5, P < .0005) compared with age- matched normal lung. CCAMs that required resection before birth had the highest cell proliferation index. There were no differences in the expression of KGF protein or KGF mRNA in CCAM and normal lung. Conclusions: These results demonstrate that CCAM differs from normal lung by increased cell proliferation and decreased apoptosis. The increased proliferation does not appear to be mediated by the pneumocyte mitogen KGF. An examination of factors that control cell proliferation and apoptosis in CCAM may provide further insight into the pathogenesis of this tumor.

Presentations

• Liechty, K. W. (2024, August). Fetal Surgery in Arizona 2024: State of the Art. Arizona Perinatal Trust Conference. Flagstaff, AZ.
• Liechty, K. W. (2024, June). Regeneration in Response to Injury: Lessons Learned from the Fetus. The University of Arizona College of Medicine Adventures in Curiosity and Care - SIMI 2024.
• Liechty, K. W. (2024, June). Wilms’ Tumor – Pediatric, Abdominal Pain - Acute – Pediatric, Abdominal Mass – Pediatric, Malrotation – Pediatric, Hypertrophic Pyloric Stenosis – Pediatric. The University of Arizona Department of Surgery Residency Chief Boot Camp. Tucson, Az.
• Liechty, K. W. (2024, October). Development of a Pediatric Fetal Neurosurgery Program. Arizona Neurosurgical Society Annual Meeting. Phoenix, AZ.
• Liechty, K. W. (2023, May). Regeneration in Response to Injury: Lessons Learned from the Fetus. University of Arizona Department of Surgery Research Day. Tucson, AZ: University of Arizona.
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  Lecture
• Liechty, K. W. (2023, November). Regeneration in Response to Injury: Lessons Learned from the Fetus. CarePoint Health Organization.
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  Lecture
• Liechty, K. W. (2023, November). Regeneration in Response to Injury: Lessons Learned from the Fetus. Skin Research Group of Canada 10th Annual Conference. Canada.
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• Liechty, K. W. (2023, November). Regeneration in Response to Injury: Lessons Learned from the Fetus. Surgery Grand Rounds. Tucson, AZ: University of Arizona.
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• Liechty, K. W. (2023, October). Regeneration in Response to Injury: Lessons Learned from the Fetus. Diabetic Wounds Treatment Consensus Panel. Connecticut: Yale University.
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• Liechty, K. W. (2023, October). Regeneration in Response to Injury: Lessons Learned from the Fetus. Robert Christensen Lectureship. Utah: University of Utah.
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  Lecture

Others

• Guthrie, E., Fortier, K., Liechty, K. W., & Price, N. (2023, August). Pediatric Surgical Antibiotic Preoperative Prophylaxis Guidelines for Elective Surgery.
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  Guideline to assist in choosing antibiotic prophylaxis for children undergoing elective procedures.  Used by the Banner system.