High Rates of Central Venous Line Replacement or Revision in Children With Cancer at US Children's Hospitals.

BACKGROUND: Most children with cancer utilize a central venous line (CVL) for treatment. Complications often necessitate early replacement, revision, or addition (RRA), but the rate of these procedures is not known. This study sought to determine rates of RRA in pediatric oncology patients, and associated risk factors. MATERIALS AND METHODS: Data queried from the Pediatric Health Information System including patients ≤18 years old with malignancy and CVL placement. Analysis included: first CVL placement of the calendar year and subsequent procedures for 6 months thereafter. RESULTS: A total of 6553 children met inclusion criteria (55.9% male, median age 6 years, interquartile range: 2 to 12). RRA within 6 months was required in 25.6% of patients, with 1.7% requiring 5 or more lines. Patients with Central Line-Associated Bloodstream Infection (CLABSI) were 2.78 times more likely to require RRA within 6 months of initial CVL placement, but accounted for only 16% of RRA patients. Factors associated with RRA were age below 1 year, CLABSI, hematologic malignancy, malnutrition, clotting disorder, deep vessel thromboembolism, and obesity. Patients with implantable ports as initial CVL (42%) were less likely to need RRA. CONCLUSION: Twenty-five percent require at least 1 RRA within 6 months, with associated morbidity and costs. Though strongly associated, most revisions were not related to CLABSI episodes.

General Surgery Residency Application Evaluation in a USMLE Step 1 Pass/Fail World: A Retrospective Comparison.

Introduction The United States Medical Licensure Exam (USMLE) Step 1 has been used as both a licensing exam and a way for residency programs to evaluate applicants. It has had significant impact upon the match process over time. With the 2020 decision to make the exam pass/fail due to its unclear validity as an evaluation for future physician performance, programs will go through the match without the Step 1 score. We set out to better understand the effects of the exam score on our selection process, with the hypothesis that without the step 1 score, the ranking of our applicants would be significantly altered. Methods We performed a retrospective analysis of applications to a single General Surgery residency program with 4 categorial residents per year at a physician led, academic, tertiary care medical center from 2017-2020. Important applicant factors including USMLE Step 1 and 2, AOA status, science grades, clerkship scores, audition rotations, volunteer activities, research activities, letters of recommendation, and personal statements were given points and evaluated through our equation, the sum of which was used to create a rank list and offer interviews. The standard deviation of scores was calculated with and without Step 1, and the distribution of scores compared. The range and average of applicants' change in point scores were examined. Results The applications of 653 students were reviewed. After removal of USMLE step 1 points, 40% of all applicants decreased in rank, 35% remained the same, and 24% increased. Specifically, 18.8% of the top third dropped to the middle third, and 11.7% of the bottom third jumped to the middle third, while the middle third changed little (0.2% dropped and 0.9% jumped out of middle third). The points given for USMLE step 1 created a wider distribution of scores with a negative skewness, suggesting there were more applicants below the mean than above. After removing those points, applicants' scores had a narrower distribution and skewness closer to 0, showing fewer upper outliers and more applicants near the mean. Conclusions The USMLE Step 1 score significantly affected the evaluation of applicants, and the removal of it from the recruitment criteria tightened applicant rankings. The elimination of the USMLE Step 1 score in the assessment of applicants will allow for its replacement with variables that better reflect the core values of residency programs.

Identifying Outlier Hospitals in Gastric Cancer Lymph Node Yield Using the National Cancer Database.

BACKGROUND: Lymph node (LN) yield is a key quality indicator that is associated with improved staging in surgically resected gastric cancer. The National Comprehensive Cancer Network recommends a yield of ≥15 LNs for proper staging, yet most facilities in the United States fail to achieve this number. The present study aimed to identify factors that could affect LN yield on a facility level and identify outlier hospitals. METHODS: This was a retrospective review of adults (aged ≥18 y) with gastric cancer (Tumor-Node-Metastasis Stages I-III) who underwent gastrectomy. Data were analyzed from the National Cancer Database (2004-2016). Multivariate analysis identified patient and tumor characteristics, whereas an observed-to-expected ratio of identified outlier hospitals. Facility factors were compared between high and low outliers. RESULTS: A total of 26,590 patients were included in this study. Of these patients, only 50.3% had an LN yield ≥15. The multivariate model of patient and tumor characteristics demonstrated a concordance index was 0.684. A total of 1245 facilities were included. There were 198 low outlier LN yield hospitals and 135 high outlier LN yield hospitals (observed-to-expected ratio of 0.42 ± 0.24 versus 1.38 ± 0.19, P < 0.0001). There was a difference in facility type between low and high outliers (P < 0.0001). High LN yield hospitals had a larger surgical volume than low LN yield hospitals (median 8.4 [4.9, 13.5] versus 3.5 [2.4, 5.2]; P < 0.0001). CONCLUSIONS: Nearly half of the population exhibited low compliance to National Comprehensive Cancer Network recommendations. Facility-level disparities exist as high yearly surgical volume and academic facility status distinguished high-performing outlier hospitals.

ROCK1 inhibitor stabilizes E-cadherin and improves barrier function in experimental necrotizing enterocolitis.

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of newborns. Although incompletely understood, NEC is associated with intestinal barrier dysfunction. E-cadherin, an adherens junction, is a protein complex integral in maintaining normal barrier homeostasis. Rho-associated protein kinase-1 (ROCK1) is a kinase that regulates the E-cadherin complex, and p120-catenin is a subunit of the E-cadherin complex that has been implicated in stabilizing the cadherin complex at the plasma membrane. We hypothesized that E-cadherin is decreased in NEC and that inhibition of ROCK1 would protect against adherens junction disruption. To investigate this, a multimodal approach was used: In vitro Caco-2 model of NEC (LPS/TNFα), rap pup model (hypoxia + bacteria-containing formula), and human intestinal samples. E-cadherin was decreased in NEC compared with controls, with relocalization from the cell border to an intracellular location. ROCK1 exhibited a time-dependent response to disease, with increased early expression in NEC and decreased expression at later time points and disease severity. Administration of ROCK1 inhibitor (RI) resulted in preservation of E-cadherin expression at the cell border, preservation of intestinal villi on histological examination, and decreased apoptosis. ROCK1 upregulation in NEC led to decreased association of E-cadherin to p120 and increased intestinal permeability. RI helped maintain the stability of the E-cadherin-p120 complex, leading to improved barrier integrity and protection from experimental NEC.NEW & NOTEWORTHY This paper is the first to describe the effect of ROCK1 on E-cadherin expression in the intestinal epithelium and the protective effects of ROCK inhibitor on E-cadherin stability in necrotizing enterocolitis.

Echocardiography Reveals Heart Abnormalities in Pediatric Pectus Carinatum.

BACKGROUND: Symptoms including chest pain and palpitations are commonly described by pediatric patients with pectus deformity. Cardiac anomalies are thought to be less common in patients with pectus carinatum (PC) than those in patients with pectus excavatum; however, no literature supports this presumption. Echocardiogram (echo) assesses heart structure and function. We hypothesized that a screening echo would 1) determine the relationship between symptoms and echo findings and 2) define the incidence of cardiac defects in patients with PC. MATERIALS AND METHODS: This is an institutional review board-approved retrospective review of all patients with PC who received an echo from 2015 to 2019 at a tertiary care children's hospital. Echo findings and patient-reported symptoms were collected from electronic health records. Descriptive statistics were used to assess correlation between findings. RESULTS: We identified 155 patients with PC who received an echo with complete data available for analysis. Of these, 44 (28.4%) reported chest pain and 13 (8.4%) reported palpitations. Echo results showed that five patients (3.2%) had mitral valve prolapse and 11 (7.1%) had aortic root dilation. Patient-reported symptoms were not significantly associated with abnormal echo findings. CONCLUSIONS: Chest pain and palpitations frequently occur in the PC population but may not be related to abnormal echo findings. We recommend screening echo in patients with PC regardless of symptoms.

Identification of suitable reference microRNA for qPCR analysis in pediatric inflammatory bowel disease.

Pediatric inflammatory bowel disease (IBD) accounts for 10-15% of IBD and is associated with considerable morbidity for patients. Dysregulated microRNAs (miRNA, miR), small noncoding RNA molecules that modulate gene expression, have been the target of research in IBD diagnosis, surveillance, and therapy. Proper selection of reference genes, which are a prerequisite for accurate measurement of miRNA expression, is currently lacking. We hypothesize that appropriate normalization requires unique reference genes for different tissue and disease types. Through the study of 28 pediatric intestinal samples, we sought to create a protocol for selection of suitable endogenous reference genes. Candidate reference genes (miR-16, 193a, 27a, 103a, 191) were analyzed by RT-quantitative (q)PCR. Criteria used for designation of suitable reference genes were as follows: 1) ubiquitous: present in all tissue samples with quantification cycle value 15-35; 2) uniform expression: no differential expression between control and disease samples (P > 0.05); 3) stability: stability value <0.5 by NormFinder. Our results suggest the use of miR-27a/191 for Crohn's disease small bowel, none of the five candidate genes for Crohn's disease colon, and miR-16/27a for ulcerative colitis. Additionally, target miR-874 had differential expression when normalized with different reference genes. Our results demonstrate that reference gene choice for qPCR analysis has a significant effect on study results and that proper data normalization is imperative.

Alvarado Scores Predict Additive Value of Magnetic Resonance Imaging in Workup of Suspected Appendicitis in Children.

BACKGROUND: The presentation of appendicitis in pediatrics is variable, and diagnostic imaging is often used. Magnetic resonance imaging (MRI) is replacing computed tomography in some centers, particularly after a nondiagnostic ultrasound (NDUS). Nonetheless, MRI is not widely used in this setting because of cost, procedure time, institutional capacity, and high rates of negative scans. We hypothesized that the Alvarado Score (AS) could be used to determine the additive diagnostic value of MRI after an NDUS. MATERIALS AND METHODS: Retrospective review of patients aged ≤18 y at a single tertiary care children's hospital who received an ultrasound for suspected appendicitis during 10 consecutive months in 2017. NDUS were defined as nonvisualization of the appendix or secondary signs without radiologic diagnosis. AS were retrospectively calculated from the electronic medical record. Primary outcomes were pathology-confirmed appendicitis, appendectomy, and perforation. RESULTS: AS was determined for 352 patients out of 463 who met inclusion criteria (76%). Sixty-two percent had an NDUS, and 45% of these patients received MRI. Patients with high-risk AS were significantly more likely to have MRI diagnostic of appendicitis (P = 0.0015), and low-risk AS patients were more likely to have a negative or equivocal MRI (P = 0.0169). Twenty-one MRI scans were required per each additional diagnosis of appendicitis in patients with low AS after NDUS versus 4.2 in intermediate-risk AS patients and 2.1 in high-risk AS patients. CONCLUSIONS: Risk stratification with AS can help assess the additive diagnostic utility of MRI after NDUS. MRI may be overutilized for diagnosing acute appendicitis in pediatric patients with low-risk AS.

Impact of Decolonization Protocols and Recurrence in Pediatric MRSA Skin and Soft-Tissue Infections.

BACKGROUND: Methicillin-resistant staphylococcus aureus (MRSA) colonization is associated with the development of skin and soft-tissue infection in children. Although MRSA decolonization protocols are effective in eradicating MRSA colonization, they have not been shown to prevent recurrent MRSA infections. This study analyzed the prescription of decolonization protocols, rates of MRSA abscess recurrence, and factors associated with recurrence. MATERIALS AND METHODS: This study is a single-institution retrospective review of patients ≤18 y of age diagnosed with MRSA culture-positive abscesses who underwent incision and drainage (I&D) at a tertiary-care children's hospital. The prescription of an MRSA decolonization protocol was recorded. The primary outcome was MRSA abscess recurrence. RESULTS: Three hundred ninety-nine patients with MRSA culture-positive abscesses who underwent I&D were identified. Patients with previous history of abscesses, previous MRSA infection groin/genital region abscesses, higher number of family members with a history of abscess/cellulitis or MRSA infection, and I&D by a pediatric surgeon were more likely to be prescribed decolonization. Decolonized patients did not have lower rates of recurrence. Recurrence was more likely to occur in patients with previous abscesses, previous MRSA infection, family history of abscesses, family history of MRSA infection, Hispanic ethnicity, and those with fever on admission. CONCLUSIONS: MRSA decolonization did not decrease the rate of recurrence of MRSA abscesses in our patient cohort. Patients at high risk for MRSA recurrence such as personal or family history of abscess or MRSA infection, Hispanic ethnicity, or fever on admission did not benefit from decolonization.

Outcomes and associated ethical considerations of long-run pediatric ECMO at a single center institution.

PURPOSE: Survival of neonatal and pediatric patients undergoing extracorporeal membrane oxygenation (ECMO) ≥ 21 days has not been well described. We hypothesized that patients would have poor survival and increased long-term complications. METHODS: Retrospective, single center, review and case analysis. Tertiary-care university children's hospital including neonatal, pediatric and cardiac intensive care units. After institutional review board approval, the charts of all patients < 18 years of age undergoing ECMO for ≥ 21 continuous days were performed, and they were compared to comparative patients undergoing shorter runs. Overall survival, incidence of complications, and post-discharge recovery were recorded. RESULTS: Overall survival was 36% in patients undergoing ≥ 21 days of ECMO (N = 14). 5/8 patients with cardiopulmonary failure from acquired etiologies survived versus 0/6 patients with congenital anomalies. 1/5 survivors achieved complete recovery with no neurologic deficits. The remaining survivors suffer from multiple medical and neurodevelopmental morbidities. CONCLUSION: ECMO support for ≥ 21 days is associated with poor survival, particularly in neonates with congenital anomalies. Long-term outcomes for survivors ought to be carefully weighed and discussed with parents given the high incidence of neurologic morbidities in this population.

Perforated Appendicitis in Children: Management, Microbiology, and Antibiotic Stewardship.

Although appendicitis has been described for more than 300 years, its optimal management remains a topic of active investigation. Acute appendicitis is the most common cause of peritonitis in children, and rates of perforated appendicitis are much higher in children than in adults. Increased risk for perforated appendicitis in children is related to a delay in diagnosis due to age, size, access to care, and more. Surgical options include immediate appendectomy versus nonoperative management with intravenous antibiotics ± a drainage procedure, with a subsequent interval appendectomy. Microbiota of perforated appendicitis in children most often includes Escherichia coli, Bacteroides fragilis, Streptococcus, and more. Even though the most common organisms are known, there is a large variety of practice when it comes to postoperative antibiotic management in these patients. Studies discuss the benefits of mono- versus dual or triple therapy without a particular consensus regarding what to use. This is reflected across differing practices at various institutions. In this review, we aim to explore the implications of perforated appendicitis in pediatrics, common organisms seen, antibiotic regimen coverage, and the implications of variations of practice. Resistance to commonly used broad-spectrum antibiotics is evolving, therefore minimization of care variability is needed for improved patient outcomes and proper antibiotic stewardship.

Experimental Modeling of Necrotizing Enterocolitis in Human Infant Intestinal Enteroids.

METHODS: There are several limitations when using a single cell culture to recapitulate the findings in a complex organism and results often vary between species, when proxy animal models are studied. RESULTS: Human enteroids have allowed for study of human disease in complex multicellular culture systems. Here we present the novel use of human infant enteroids generated from premature infant intestine to study necrotizing enterocolitis (NEC), which is a devastating intestinal disorder that affects our most vulnerable pediatric population. CONCLUSIONS: We demonstrate that NEC can be induced in premature human enteroids as supported by corresponding alterations in inflammation, apoptosis, tight junction expression, and permeability by treatment with lipopolysaccharide.

Controversy in the classification of appendicitis and utilization of postoperative antibiotics.

BACKGROUND: There is wide variability and considerable controversy regarding the classification of appendicitis and the need for postoperative antibiotics. This study aimed to assess interrater agreement with respect to the classification of appendicitis and its influence on the use of postoperative antibiotics amongst surgeons and surgical trainees. METHODS: A survey comprising 15 intraoperative images captured during appendectomy was distributed to surgeons and surgical trainees. Participants were asked to classify severity of disease (normal, inflamed, purulent, gangrenous, perforated) and whether they would prescribe postoperative antibiotics. Statistical analysis included percent agreement, Krippendorff's alpha for interrater agreement, and logistic regression. RESULTS: In total, 562 respondents completed the survey: 206 surgical trainees, 217 adult surgeons, and 139 pediatric surgeons. For classification of appendicitis, the statistical interrater agreement was highest for categorization as gangrenous/perforated versus nongangrenous/nonperforated (Krippendorff's alpha = 0.73) and lowest for perforated versus nonperforated (Krippendorff's alpha = 0.45). Fourteen percent of survey respondents would administer postoperative antibiotics for an inflamed appendix, 44% for suppurative, 75% for gangrenous, and 97% for perforated appendicitis. Interrater agreement of postoperative antibiotic use was low (Krippendorff's alpha = 0.28). The only significant factor associated with postoperative antibiotic utilization was 16 or more years in practice. CONCLUSIONS: Surgeon agreement is poor with respect to both subjective appendicitis classification and objective utilization of postoperative antibiotics. This survey demonstrates that a large proportion (59%) of surgeons prescribe antibiotics after nongangrenous or nonperforated appendectomy, despite a lack of evidence basis for this practice. These findings highlight the need for further consensus to enable standardized research and avoid overtreatment with unnecessary antibiotics.

This is Our Lane: A Pilot Study Examining the Surgeon's Role in Social Justice Advocacy.

BACKGROUND: Despite the importance of social justice advocacy, surgeon attitudes toward individual involvement vary. We hypothesized that the majority of surgeons in this study, regardless of gender or training level, believe that surgeons should be involved in social justice movements. METHODS: A survey was distributed to surgical faculty and trainees at three academic tertiary care centers. Participation was anonymous with 123 respondents. Chi-square and Fisher's exact test were used for analysis with significance accepted when p < 0.05. Thematic analysis was performed on free responses. RESULTS: The response rate was 46%. Compared to men, women were more likely to state that surgeons should be involved (86% vs 64%, p = 0.01) and were personally involved in social justice advocacy (86% vs 51%, p = 0.0002). Social justice issues reported as most important to surgeons differed significantly by gender (p = 0.008). Generated themes for why certain types of advocacy involvement were inappropriate were personal choices, professionalism and relationships. CONCLUSIONS: Social justice advocacy is important to most surgeons in this study, especially women. This emphasizes the need to incorporate advocacy into surgical practice.

Have the Characteristics for Success as a Surgeon Changed? A Century of Perspective Through the American College of Surgeons.

BACKGROUND: The Presidential Address of the American College of Surgeons (ACS) is an influential platform during the convocation for new Fellows every year. Recent work reported that most ACS presidents primarily discuss personal characteristics for success; however, these qualities were never specified. Therefore, this study aimed to identify the personal characteristics that are espoused in ACS presidential addresses as essential for success as a surgeon. STUDY DESIGN: Thematic analysis was completed for every ACS presidential address (98 addresses between 1913 and 2019). Full-text addresses were reviewed (2 team members), personal characteristics were coded (1 team member) and then assembled into patterns and themes (3 team-members' consensus). A temporal frame was adopted in grouping these themes in that personal qualities that appeared consistently throughout this period were classified as Enduring Characteristics and those that emerged only in later years were classified as Recent Characteristics. RESULTS: Enduring Characteristics that were present throughout the century included sincere compassion for patients; integrity; engagement (willingness to help shape the changing field at the institutional or national level); and commitment to lifelong learning. Recent Characteristics included humility and the interpersonal attributes of inclusivity and the ability to be a collaborative team leader. CONCLUSIONS: Surgery has experienced countless paradigm shifts since 1913, and the perceived characteristics for success have similarly evolved to include more interpersonal abilities. The importance of sincere compassion for patients, integrity, engagement, and commitment to lifelong learning remained consistent for more than a century.

Timeliness of pediatric surgical appendicitis care is associated with time of hospital admission.

BACKGROUND: Despite the frequency of acute appendicitis in children, there is no evidence-based consensus surrounding the urgency of the operation if a diagnosis is made after regular business hours. Although a modest delay in time to operation does not increase disease severity, postponing cases to the next calendar day may be associated with higher resource utilization. We aimed to evaluate the trend of delaying appendectomies to the next calendar day and its associated outcomes. METHODS: We queried the Pediatric Health Information System to analyze appendectomy patients younger than 18 y of age from 2010 to 2018. Same-day appendectomy and next-day appendectomy cohorts were created using admission hour and operative day. Healthcare cost, length of stay, surgical complications, and 30-day readmission rates were collected. Bivariate analyses and multivariable regressions were used to evaluate groups stratified by time of presentation. RESULTS: During the study period, 113,662 appendectomies were performed, comprising 88,715 (78.1%) same-day appendectomies and 24,947 (21.9%) next-day appendectomies. A higher proportion of same-day appendectomies (80.5%) were performed during hours 12:00am to 5:00pm and 19.5% were performed during hours 6:00pm to 11:00pm. The trend of next-day appendectomies increased during the study period from 13.9% to 20.2%. This was primarily evident in the 6:00pm to 11:00pm period. The 5:00pm cutoff was most predictive of a next-day appendectomy. Next-day appendectomies had similar rates of surgical complications; however, they were associated with higher costs, longer lengths of stay, and higher readmission rates. CONCLUSION: As the understanding of appendicitis urgency has changed, a more tempered approach of delivering surgical care has trended. Although short delays appear safe, postponement to the next calendar day is associated with higher resource utilization.

How Applicants to General Surgery Residency Define Resilience.

OBJECTIVE: Resilience is a vital quality for the successful completion of any residency training program. Resilience is a commonly used but poorly understood term and is defined in multiple ways by people during different times of their lives. The transition from medical student to general surgical resident (GSR) is one of the most formative times in a young surgeon's professional career. The purpose of this study is to determine how a cohort of aspiring surgical residents define resilience. DESIGN: This is a qualitative study where interviews were conducted prospective GSRs over 2 application seasons. During the institution's standard interview process, applicants were asked to provide a definition of resilience. Responses were documented. Qualitative content analysis was conducted by the research team. Initial codes were developed and defined. Research team members independently coded the responses, and then an iterative group consensus process was used to develop the final themes. SETTING: This study was conducted at Geisinger Medical Center, an academic tertiary care hospital in Danville, PA with 5 categorical GSR positions per year. PARTICIPANTS: All applicants who underwent an in-person interview were included in this study. RESULTS: A total of 261 comments about resilience were available from 117 interviews. These responses were categorized into 5 themes: support, learning from failure, adaptability, self-reflection, and perseverance. CONCLUSION: Resilience as defined by applicants to a general surgery residency program is a multifaceted term. The thematic categories suggest that resilience can be viewed through the framework of the 5 components of emotional intelligence: self-aware, self-regulation, motivation, empathy, and social skills.

Should we look for Hirschsprung disease in all children with meconium plug syndrome?

BACKGROUND: Meconium plug syndrome (MPS) is associated with Hirschsprung disease (HD) in 13-38% of cases. This study sought to assess institutional variation in utilization of rectal biopsy in children with MPS and the likelihood of diagnosing HD in this population. METHODS: Patients with MPS on contrast enema in the first 30 days of life from the Pediatric Health Information System database in 2016-2017 were included. Institutional rates of rectal biopsies performed during the initial admission were calculated and then used to predict institutional rates of early HD diagnoses using Poisson regression. RESULTS: Of 373 newborns with MPS, 106 (28.4%) underwent early rectal biopsy, of whom 43 (40.5%) had HD. Fifty-seven (15.3%) were ultimately diagnosed with HD. Eight (14%) of these patients had a delayed diagnosis. HD rates between institutions did not differ significantly (range 0-50%, p=0.52), but usage of early rectal biopsy did (range 0-80%, p=0.03). Each additional early biopsy increased the early HD diagnosis rate by 35% (ß=0.30, 95% CI 0.15-0.45, p<0.0001). CONCLUSION: The incidence of HD is increased in children with MPS. There is significant hospital variability in the utilization of early rectal biopsy, and opportunity exists to standardize practice. TYPE OF STUDY: Study of Diagnostic test Level of Evidence: Level III.

Caveolin 1 is Associated with Upregulated Claudin 2 in Necrotizing Enterocolitis.

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal emergency of neonates. Epithelial tight junction (TJ) proteins, such as claudins, are essential for regulation and function of the intestinal barrier. Rho kinase (ROCK) affects cellular permeability and TJ regulation. We hypothesized that TJ protein changes would correlate with increased permeability in experimental NEC, and ROCK inhibitors would be protective against NEC by regulation of key claudin proteins. We tested this hypothesis using an in vivo rat pup model, an in vitro model of experimental NEC, and human intestinal samples from patients with and without NEC. Experimental NEC was induced in rats via hypoxia and bacteria-containing formula, and in Caco-2 cells by media inoculated with LPS. The expression of claudins was measured by gene and protein analysis. Experimental NEC in rat pups and Caco-2 cells had increased permeability compared to controls. Gene and protein expression of claudin 2 was increased in experimental NEC. Sub-cellular fractionation localized increased claudin 2 protein to the cytoskeleton. ROCK inhibition was associated with normalization of these alterations and decreased severity of experimental NEC. Co-immunoprecipitation of caveolin-1 with claudin 2 suggests that caveolin-1 may act as a shuttle for the internalization of claudin 2 seen in experimental NEC. In conclusion, NEC is associated with intestinal permeability and increased expression of claudin 2, increased binding of caveolin-1 and claudin 2, and increased trafficking of claudin 2 to the cytoskeleton.

A Novel Human Epithelial Enteroid Model of Necrotizing Enterocolitis.

Necrotizing enterocolitis (NEC) is a devastating disease of newborn infants. It is characterized by multiple pathophysiologic alterations in the human intestinal epithelium, leading to increased intestinal permeability, impaired restitution, and increased cell death. Although there are numerous animal models of NEC, response to injury and therapeutic interventions may be highly variable between species. Furthermore, it is ethically challenging to study disease pathophysiology or novel therapeutic agents directly in human subjects, especially children. Therefore, it is highly desirable to develop a novel model of NEC using human tissue. Enteroids are 3-dimensional organoids derived from intestinal epithelial cells. They are ideal for the study of complex physiologic interactions, cell signaling, and host-pathogen defense. In this manuscript we describe a protocol that cultures human enteroids after isolating intestinal stem cells from patients undergoing bowel resection. The crypt cells are cultured in media containing growth factors that encourage differentiation into the various cell types native of the human intestinal epithelium. These cells are grown in a synthetic, collagenous mix of proteins that serve as a scaffold, mimicking the extra-cellular basement membrane. As a result, enteroids develop apical-basolateral polarity. Co-administration of lipopolysaccharide (LPS) in media causes an inflammatory response in the enteroids, leading to histologic, genetic, and protein expression alterations similar to those seen in human NEC. An experimental model of NEC using human tissue may provide a more accurate platform for drug and treatment testing prior to human trials, as we strive to identify a cure for this disease.

Utility of liver biopsy in the evaluation of pediatric total parenteral nutrition cholestasis.

BACKGROUND: Cholestasis is a serious complication of total parenteral nutrition (TPN) in neonates. Liver biopsies may be requested to assess the severity of cholestasis and fibrosis. We hypothesized that liver biopsy would not lead to changes in management or improved patient outcomes. METHODS: A single institution retrospective review of infants with TPN cholestasis from January 2008 to January 2016. OUTCOMES: length of stay, complications, change in management and mortality. Statistical analysis was performed using Fisher's exact test. RESULTS: Twenty-seven out of 95 patients with TPN cholestasis underwent liver biopsy. Liver biopsy was associated with increased utilization or ursodeoxycholic acid (p = 0.001). There were no differences in length of stay (LOS) or mortality. One patient had a complication following anesthesia for liver biopsy, there were no bleeding complications recorded. CONCLUSIONS: Liver biopsy in patients with TPN cholestasis was associated with an increase in utilization of ursodeoxycholic acid. The effects of this are not fully understood; however, liver biopsy was not associated with improved patient outcomes such as LOS or mortality.