Douglas A. Potoka

Impact of pediatric trauma centers on mortality in a statewide system.

Background: Regional pediatric trauma centers (PTC) were established to optimize the care of injured children. However, because of the relative shortage of PTC, many injured children continue to be treated at adult trauma centers (ATC). As a result, a growing controversy has evolved regarding the impact of PTC and ATC on outcome for injured children. Methods: A retrospective analysis of 13,351 injured children entered in the Pennsylvania Trauma Outcome Study between 1993 and 1997 was conducted. Patients were stratified according to mechanism of injury, injury severity, specific organ injury, and type of trauma center: PTC; Level I ATC (ATC I); Level II ATC (ATC II); or ATC with added qualifications to treat children (ATC AQ). Mortality was the major outcome variable measured. Results: Most injured children were treated at a PTC or ATC AQ. The majority of children below 10 years of age were admitted to PTC. Patients treated at PTC and ATC had similar injury severity as determined by median Injury Severity Score, mean Revised Trauma Score, and Glasgow Coma Scale. Overall survival was significantly better at PTC and ATC AQ compared with ATC I and ATC II. Survival for head, spleen, and liver injuries was significantly better at PTC compared with ATC AQ, ATC I, or ATC II. Children who sustained moderate or severe head injuries were more likely to undergo neurosurgical intervention and have a better outcome when treated at a PTC. Despite similar mean Abbreviated Injury Scores for spleen and liver, significantly more children underwent surgical exploration (especially splenectomy) for spleen and liver injuries at ATC compared with PTC. Conclusion: Children treated at PTC or ATC AQ have significantly better outcome compared with those treated at ATC. Severely injured children (Injury Severity Score > 15) with head, spleen, or liver injuries had the best overall outcome when treated at PTC. This difference in outcome may be attributable to the approach to operative and nonoperative management of head, liver, and spleen injuries at PTC.

Improved functional outcome for severely injured children treated at pediatric trauma centers.

BACKGROUND Controversy exists regarding the impact of pediatric trauma centers (PTC) on survival for injured children. However, functional outcome for children treated at PTC compared with adult trauma centers (ATC) has not been evaluated. METHODS An analysis of children entered in the Pennsylvania Trauma Outcome Study between 1993 and 1997 was conducted. Patients were stratified according to type of trauma center: PTC; Level I ATC; Level II ATC; or ATC with added qualifications (AQ). Functional outcome at discharge was analyzed. RESULTS For severely injured children, there was an overall trend toward improved functional outcome at PTC compared with ATC AQ and ATC I, but no difference compared with ATC II. PTC showed improved functional outcome at discharge for head injury compared with ATC AQ and ATC I. CONCLUSION There is an overall trend toward improved functional outcome at discharge for children treated at PTC compared with those treated at ATC AQ and ATC I. Improved outcome for head injury may be a key factor contributing to improved outcome at PTC.

Lipopolysaccharide Induces Cyclooxygenase-2 in Intestinal Epithelium via a Noncanonical p38 MAPK Pathway

Necrotizing enterocolitis (NEC), a severe intestinal inflammation in neonates, occurs following bacterial colonization of the gut. LPS-induced production of inflammatory factors in immature enterocytes may be a factor in NEC. Previously, we described LPS-induced p38 MAPK-dependent expression of cyclooxygenase-2 (COX-2) in rat IEC-6 cells. In this study, we examine COX-2 expression in newborn rat intestinal epithelium and further characterize the mechanisms of COX-2 regulation in enterocytes. Induction of NEC by formula feeding/hypoxia increased phospho-p38 and COX-2 levels in the intestinal mucosa. Celecoxib, a selective COX-2 inhibitor, exacerbated the disease, suggesting a protective role for COX-2. COX-2 was induced in the intestinal epithelium by LPS in vivo and ex vivo. The latter response was attenuated by the p38 inhibitor SB202190, but not by inhibitors of ERK, JNK, or NF-κB. In IEC-6 enterocytes, COX-2 was induced by the expression of MAPK kinase 3 EE (MKK3EE), a constitutive activator of p38, but not of activators of ERK or JNK pathways. However, neither MKK3/6 nor MKK4, the known p38 upstream kinases, were activated by LPS. Dominant-negative MKK3 or MKK4 or SB202190 failed to prevent LPS-induced, p38-activating phosphorylation, ruling out important roles of these kinases or p38 autophosphorylation. LPS increased COX-2 and activating phosphorylation of p38 with similar dose-response. Blockade of LPS-induced expression of COX-2-luciferase reporter and destabilization of COX-2 message by SB202190 indicate that p38 regulates COX-2 at transcription and mRNA stability levels. Our data indicate that p38-mediated expression of COX-2 proceeds through a novel upstream pathway and support the role of the neonate’s enterocytes as bacterial sensors.

Variants in GATA4 are a rare cause of familial and sporadic congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is characterized by incomplete formation of the diaphragm occurring as either an isolated defect or in association with other anomalies. Genetic factors including aneuploidies and copy number variants are important in the pathogenesis of many cases of CDH, but few single genes have been definitively implicated in human CDH. In this study, we used whole exome sequencing (WES) to identify a paternally inherited novel missense GATA4 variant (c.754C>T; p.R252W) in a familial case of CDH with incomplete penetrance. Phenotypic characterization of the family included magnetic resonance imaging of the chest and abdomen demonstrating asymptomatic defects in the diaphragm in the two “unaffected” missense variant carriers. Screening 96 additional CDH patients identified a de novo heterozygous GATA4 variant (c.848G>A; p.R283H) in a non-isolated CDH patient. In summary, GATA4 is implicated in both familial and sporadic CDH, and our data suggests that WES may be a powerful tool to discover rare variants for CDH.

Developmental outcomes of children with congenital diaphragmatic hernia: a multicenter prospective study.

PURPOSE To determine developmental outcomes and associated factors in patients with congenital diaphragmatic hernia (CDH) at 2 years of age. METHODS This is a multicenter prospective study of a CDH birth cohort. Clinical and socioeconomic data were collected. Bayley Scales of Infant Development (BSID-III) and Vineland Adaptive Behavior Scales (VABS-II) were performed at 2 years of age. RESULTS BSID-III and VABS-II assessments were completed on 48 and 49 children, respectively. The BSID-III mean cognitive, language, and motor scores were significantly below the norm mean with average scores of 93 ± 15, 95 ± 16, and 95 ± 11. Ten percent (5/47) scored more than 2 standard deviations below the norm on one or more domains. VABS-II scores were similar to BSID-III scores with mean communication, daily living skills, social, motor, adaptive behavior scores of 97 ± 14, 94 ± 16, 93 ± 13, 97 ± 10, and 94 ± 14. For the BSID-III, supplemental oxygen at 28 days, a prenatal diagnosis, need for extracorporeal membrane oxygenation (ECMO) and exclusive tube feeds at time of discharge were associated with lower scores. At 2 years of age, history of hospital readmission and need for tube feeds were associated with lower scores. Lower socioeconomic status correlated with lower developmental scores when adjusted for significant health factors. CONCLUSION CDH patients on average have lower developmental scores at 2 years of age compared to the norm. A need for ECMO, oxygen at 28 days of life, ongoing health issues and lower socioeconomic status are factors associated with developmental delays.

Embryonic mouse blood flow and oxygen correlate with early pancreatic differentiation

The mammalian embryo represents a fundamental paradox in biology. Its location within the uterus, especially early during development when embryonic cardiovascular development and placental blood flow are not well-established, leads to an obligate hypoxic environment. Despite this hypoxia, the embryonic cells are able to undergo remarkable growth, morphogenesis, and differentiation. Recent evidence suggests that embryonic organ differentiation, including pancreatic β-cells, is tightly regulated by oxygen levels. Since a major determinant of oxygen tension in mammalian embryos after implantation is embryonic blood flow, here we used a novel survivable in utero intracardiac injection technique to deliver a vascular tracer to living mouse embryos. Once injected, the embryonic heart could be visualized to continue contracting normally, thereby distributing the tracer specifically only to those regions where embryonic blood was flowing. We found that the embryonic pancreas early in development shows a remarkable paucity of blood flow and that the presence of blood flow correlates with the differentiation state of the developing pancreatic epithelial cells in the region of the blood flow.

De novo copy number variants are associated with congenital diaphragmatic hernia

Background Congenital diaphragmatic hernia (CDH) is a common birth defect with significant morbidity and mortality. Although the aetiology of CDH remains poorly understood, studies from animal models and patients with CDH suggest that genetic factors play an important role in the development of CDH. Chromosomal anomalies have been reported in CDH. Methods In this study, the authors investigated the frequency of chromosomal anomalies and copy number variants (CNVs) in 256 parent–child trios of CDH using clinical conventional cytogenetic and microarray analysis. The authors also selected a set of CDH related training genes to prioritise the genes in those segmental aneuploidies and identified the genes and gene sets that may contribute to the aetiology of CDH. Results The authors identified chromosomal anomalies in 16 patients (6.3%) of the series including three aneuploidies, two unbalanced translocation, and 11 patients with de novo CNVs ranging in size from 95 kb to 104.6 Mb. The authors prioritised the genes in the CNV segments and identified KCNA2, LMNA, CACNA1S, MYOG, HLX, LBR, AGT, GATA4, SOX7, HYLS1, FOXC1, FOXF2, PDGFA, FGF6, COL4A1, COL4A2, HOMER2, BNC1, BID, and TBX1 as genes that may be involved in diaphragm development. Gene enrichment analysis identified the most relevant gene ontology categories as those involved in tissue development (p=4.4×10−11) or regulation of multicellular organismal processes (p=2.8×10−10) and ‘receptor binding’ (p=8.7×10−14) and ‘DNA binding transcription factor activity’ (p=4.4×10−10). Conclusions The present findings support the role of chromosomal anomalies in CDH and provide a set of candidate genes including FOXC1, FOXF2, PDGFA, FGF6, COL4A1, COL4A2, SOX7, BNC1, BID, and TBX1 for further analysis in CDH.

A new method for estimating probability of survival in pediatric patients using revised TRISS methodology based on age-adjusted weights

BACKGROUND TRISS methodology estimates probability of survival (P(s)) based on coefficients derived largely from adult data. We developed a novel pediatric age-specific method to estimate P(s). METHODS The Pennsylvania Trauma Outcome Study database was queried for pediatric patients injured between 1993 and 1996 (n = 9730). P(s) derived from the Pediatric Age-Adjusted TRISS (PAAT) methodology was generated using our Age-Specific Pediatric Trauma Score and Injury Severity Score with corresponding weights. A test data set of 7138 pediatric patients entered in the Pennsylvania Trauma Outcome Study from 1997 to 1999 was used to compute an expected number of survivors for PAAT, TRISS, and ASCOT (A Severity Characteristic of Trauma). Observed and expected survival were compared for blunt injured patients, for head injured patients, and by age category. RESULTS PAAT showed no significant difference between observed and expected survival. TRISS and ASCOT significantly underestimated overall survival: across age groups, for blunt injuries, for head injuries, and for patients whose P(s) was less than 91%. CONCLUSION PAAT offers a more reliable methodology than TRISS and ASCOT for comparing pediatric trauma outcomes.

Whole exome sequencing identifies de novo mutations in GATA6 associated with congenital diaphragmatic hernia

Background Congenital diaphragmatic hernia (CDH) is a common birth defect affecting 1 in 3000 births. It is characterised by herniation of abdominal viscera through an incompletely formed diaphragm. Although chromosomal anomalies and mutations in several genes have been implicated, the cause for most patients is unknown. Methods We used whole exome sequencing in two families with CDH and congenital heart disease, and identified mutations in GATA6 in both. Results In the first family, we identified a de novo missense mutation (c.1366C>T, p.R456C) in a sporadic CDH patient with tetralogy of Fallot. In the second, a nonsense mutation (c.712G>T, p.G238*) was identified in two siblings with CDH and a large ventricular septal defect. The G238* mutation was inherited from their mother, who was clinically affected with congenital absence of the pericardium, patent ductus arteriosus and intestinal malrotation. Deep sequencing of blood and saliva-derived DNA from the mother suggested somatic mosaicism as an explanation for her milder phenotype, with only approximately 15% mutant alleles. To determine the frequency of GATA6 mutations in CDH, we sequenced the gene in 378 patients with CDH. We identified one additional de novo mutation (c.1071delG, p.V358Cfs34*). Conclusions Mutations in GATA6 have been previously associated with pancreatic agenesis and congenital heart disease. We conclude that, in addition to the heart and the pancreas, GATA6 is involved in development of two additional organs, the diaphragm and the pericardium. In addition, we have shown that de novo mutations can contribute to the development of CDH, a common birth defect.

Mechanism of Intestinal-Derived fungal sepsis by gliotoxin, a fungal metabolite☆

BACKGROUND/PURPOSE Gut barrier dysfunction resulting from fungal overgrowth may be caused by the interaction of gliotoxin (GT), a fungal metabolite, with enterocytes. The goal of this study was to determine the mechanisms by which gliotoxin (GT), a fungal metabolite, causes enterocyte apoptosis. METHODS The authors measured enterocyte apoptosis, caspase-3 activity, pro-caspase-3, and poly (ADP-ribose) polymerase (PARP) cleavage in GT-exposed IEC-6 cells, a rat intestinal cell line. RESULTS GT induced apoptosis in IEC-6 cells. The pan-caspase inhibitor ZVAD suppressed this GT-mediated apoptosis. GT induced a 15-fold increase in caspase-3 activity over media control. The authors detected PARP cleavage by after GT exposure. DTT pretreatment decreased apoptosis compared with GT alone. CONCLUSIONS This study supports the concept that fungal overgrowth may lead to gut barrier dysfunction by the local release of gliotoxin and the induction enterocyte apoptosis.