Organ Mapping Antibody Panels: a community resource for standardized multiplexed tissue imaging.

Multiplexed antibody-based imaging enables the detailed characterization of molecular and cellular organization in tissues. Advances in the field now allow high-parameter data collection (>60 targets); however, considerable expertise and capital are needed to construct the antibody panels employed by these methods. Organ mapping antibody panels are community-validated resources that save time and money, increase reproducibility, accelerate discovery and support the construction of a Human Reference Atlas.

Spatial mapping of protein composition and tissue organization: a primer for multiplexed antibody-based imaging.

Tissues and organs are composed of distinct cell types that must operate in concert to perform physiological functions. Efforts to create high-dimensional biomarker catalogs of these cells have been largely based on single-cell sequencing approaches, which lack the spatial context required to understand critical cellular communication and correlated structural organization. To probe in situ biology with sufficient depth, several multiplexed protein imaging methods have been recently developed. Though these technologies differ in strategy and mode of immunolabeling and detection tags, they commonly utilize antibodies directed against protein biomarkers to provide detailed spatial and functional maps of complex tissues. As these promising antibody-based multiplexing approaches become more widely adopted, new frameworks and considerations are critical for training future users, generating molecular tools, validating antibody panels, and harmonizing datasets. In this Perspective, we provide essential resources, key considerations for obtaining robust and reproducible imaging data, and specialized knowledge from domain experts and technology developers.

Long-Lived Charge Separation in Single Crystals of an Electron Donor Covalently Linked to Four Acceptor Molecules.

Crystalline donor-acceptor (D-A) systems serve as an excellent platform for studying CT exciton creation, migration, and dissociation into free charge carriers for solar energy conversion. Donor-acceptor cocrystals have been utilized to develop an understanding of CT exciton formation in ordered organic solids; however, the strong electronic coupling of the D and A units can sometimes limit charge separation lifetimes due to their close proximity. Covalent D-A systems that preorganize specific donor-acceptor structures can assist in engineering crystal morphologies that promote long-lived charge separation to overcome this limitation. Here we investigate photogenerated CT exciton formation in a single crystal of a 2,5,8,11-tetraphenylperylene (PerPh4) donor to which four identical naphthalene-(1,4:5,8)-bis(dicarboximide) (NDI) electron acceptors are covalently attached at the para positions of the PerPh4 phenyl groups to yield PerPh4-NDI4. X-ray crystallography shows that the four NDIs pack pairwise into two distinct motifs. Two NDI acceptors of one PerPh4-NDI4 are positioned over the PerPh4 donors of adjacent PerPh4-NDI4 molecules with the donor and acceptor π-systems having a large dihedral angle between them, while the other two NDIs of PerPh4-NDI4 form xylene-NDI van der Waals π-stacks with the corresponding NDIs in adjacent PerPh4-NDI4 molecules. Upon selective photoexcitation of PerPh4 in the single crystal, CT exciton formation occurs in <300 fs yielding electron-hole pairs that live for more than ∼16 µs. This demonstrates the effectiveness of covalently linked D-A systems for engineering single crystal structures that promote efficient and long-lived charge separation for solar energy conversion.

Two-Dimensional Electronic Spectroscopy Reveals Vibrational Modes Coupled to Charge Transfer in a Julolidine-BODIPY Dyad.

Understanding charge transfer (CT) dynamics in molecular donor-acceptor (D-A) dyads can provide insight into developing efficient D-A molecules for capturing solar energy. Here, we characterize the excited-state evolution of a julolidine-BODIPY (Jul-BD) D-A system with an emissive CT state using time-resolved fluorescence, femtosecond transient absorption, and two-dimensional electronic spectroscopies. Comparison of these results with those from phenyl-BODIPY (Ph-BD) allows us to identify the dynamics at play during CT state formation and its subsequent conversion to either a fully charge-separated or triplet state. Photoexcitation of Jul-BD in tetrahydrofuran results in the formation of an initial emissive CT state that relaxes before fully charge-separating. In contrast, Jul-BD in toluene exhibits similar CT state dynamics, albeit at slower timescales, before decaying to a terminal triplet species. Quantum beat analysis at early times in both solvents shows several vibronic modes, which are corroborated using density functional theory (DFT) calculations. For Ph-BD, a single 220 cm-1 compression mode about the single bond linking the phenyl to BODIPY modulates their orbital overlap. Three active vibronic modes, 147, 174, and 214 cm-1, are found in Jul-BD, regardless of the dielectric constant of the medium. These motions correspond to compression and torsional motions along the single bond joining Jul to BD and are responsible for the evolution of the spontaneous and stimulated emission features in the time-resolved spectroscopic data, which is further supported by time-dependent DFT calculations of the steady-state absorption spectrum of the Jul-BD as a function of increasing D-A dihedral core angle. These findings show how torsional and compression motions can play a pivotal role in intramolecular CT between a D and an A linked by a single bond.

Establishing Reference Values for Lean Muscle Mass in the Pediatric Patient.

OBJECTIVES: Adults with decreased muscle mass experience worse outcomes and more frequent complications. The effects of sarcopenia on pediatric outcomes are unknown. Our objective was to define reference values for lean muscle mass in a healthy pediatric population to facilitate future studies on the impact of lean muscle mass on pediatric outcomes. PATIENTS AND METHODS: Bilateral psoas muscle surface area was measured by computed tomography in a healthy pediatric population undergoing evaluation after trauma. Pearson correlation coefficients (PCCs) were calculated for age, weight, height, body mass index (BMI), total psoas muscle area, and psoas muscle index (PMI; defined as psoas muscle area divided by height squared). Quantile regression was used to determine age- and sex-specific percentiles of psoas muscle area and PMI. RESULTS: Analysis of 494 male and 288 female patients with available imaging (median age: 9.3 years, interquartile range: 5.4-13.4; 63.1% male) was performed. For males, age correlated strongly with total psoas volume (PCC = 0.87), height (0.95), and weight (0.88) and poorly with BMI (0.45). In females, age correlated strongly with total psoas volume (0.88), height (0.92), weight (0.88) and poorly with BMI (0.19). Gender-specific curves and charts were created using output from the quantile regression from reference values of the total psoas muscle area corresponding to the 25th, 50th, and 75th percentiles across all ages. CONCLUSIONS: We created gender-specific reference charts for total and height-normalized psoas muscle area in healthy children based on age. These results can be used in future studies to establish the effects of sarcopenia in pediatric patients.

Orientation in Perpetuity: An Online Clinical Decision Support System for Surgical Residents.

BACKGROUND: Limiting variability is an essential element to improving quality of care. Frequent resident turnover represents a significant barrier to clinical standardization. Trainees joining new surgical services must familiarize themselves with the guidelines and protocols that direct patient care as well as their learning objectives and expectations. A clinical decision support system (CDSS) is a dynamic, searchable electronic resource intended for use at the point of care. The CDSS can provide convenient and timely access to relevant information for residents, allowing them to incorporate the most up-to-date protocols and guidelines in their daily care of patients. The objective of this quality improvement intervention was to determine the objective rate of CDSS utilization and its subjective value to residents. MATERIALS AND METHODS: An internally developed, web-based CDSS including essential, clinically useful documents was created for use by trainees on a busy pediatric surgery service. A standardized orientation was provided to each resident and fellow on joining the service, complemented by a summary card to be attached to the trainee's ID badge. CDSS usage was monitored using web analytics. Trainees who rotated before and after the CDSS launch were surveyed regarding attitudes toward clinical resources and confidence in patient management. RESULTS: Documents published to the CDSS included 33 clinical guideline documents and 207 additional educational and support files including reference materials from service orientation were made available to trainees and staff. Goals for resident usage were established by evaluation and adaptation of early traffic patterns. Analysis of web traffic collected over 14 consecutive months revealed utilization above target levels, with 4.0 average weekly page views per trainee (IQR: 1.6-5.6). A total of 60 survey responses were received (54% of trainees invited); majorities of rotating trainees and survey respondents were trainees in general surgery and most were interns. Mean composite scores reflected a trend toward improved satisfaction when seeking CDSM (before intervention 3.18 [SD 0.73], after intervention 3.92 [SD 0.70], range 1-5) which was statistically significant (P = 0.005). Mean scores also improved across five of six components of the composite score (mean improvement 0.75, range: 0.53-0.92), four of which were statistically significant (P = 0.001-0.038). Most (59%) respondents reported that they used the CDSS frequently. CONCLUSIONS: Convenient access to a CDSS resulted in greater than expected utilization as well as higher resident satisfaction with and confidence in materials provided. A CDSS is a promising tool offering quick access to high-quality information in challenging trainee environments.

One-Pot Synthesis of a Linear [4]Catenate Using Orthogonal Metal Templation and Ring-Closing Metathesis.

The efficient synthesis of well-defined, linear oligocatenanes possessing multiple mechanical bonds remains a formidable challenge in the field of mechanically interlocked molecules. Here, a one-pot synthetic strategy is described to prepare a linear [4]catenate using orthogonal metal templation between a macrocycle precursor, composed of terpyridine and phenanthroline ligands spaced by flexible glycol linkers, and a closed phenanthroline-based molecular ring. Implementation of two simultaneous ring-closing metathesis reactions after metal complexation resulted in the formation of three mechanical bonds. The linear [4]catenate product was isolated in 55% yield as a mixture of topological diastereomers. The intermediate metal complexes and corresponding interlocked products (with and without metals) were characterized by nuclear magnetic resonance, mass spectrometry, gel permeation chromatography, and UV-vis absorption spectroscopy. We envision that this general synthetic strategy may pave the way for the synthesis of higher order linear oligocatenates/catenanes with precise molecular weights and four or more interlocking molecular rings.

Photoredox-Based Actuation of an Artificial Molecular Muscle.

The use of light to actuate materials is advantageous because it represents a cost-effective and operationally straightforward way to introduce energy into a stimuli-responsive system. Common strategies for photoinduced actuation of materials typically rely on light irradiation to isomerize azobenzene or spiropyran derivatives, or to induce unidirectional rotation of molecular motors incorporated into a 3D polymer network. Although interest in photoredox catalysis has risen exponentially in the past decade, there are far fewer examples where photoinduced electron transfer (PET) processes are employed to actuate materials. Here, a novel mode of actuation in a series of redox-responsive hydrogels doped with a visible-light-absorbing ruthenium-based photocatalyst is reported. The hydrogels are composed primarily of polyethylene glycol and low molar concentrations of a unimolecular electroactive polyviologen that is activated through a PET mechanism. The rate and degree of contraction of the hydrogels are measured over several hours while irradiating with blue light. Likewise, the change in mechanical properties-determined through oscillatory shear rheology experiments-is assessed as a function of polyviologen concentration. Finally, an artificial molecular muscle is fabricated using the best-performing hydrogel composition, and its ability to perform work, while irradiated, is demonstrated by lifting a small weight.

Paget-Schroetter syndrome in 21 children: outcomes after multidisciplinary care.

OBJECTIVE: To review the presentation, management, and outcomes of Paget-Schroetter syndrome (PSS) in children and propose a multidisciplinary treatment algorithm involving pediatric and vascular surgery, interventional radiology, and hematology. STUDY DESIGN: Patients with PSS presenting between 2003 and 2013 were reviewed. Demographics, symptoms, therapies, and functional outcomes were noted. Data from early patients informed the development of a multidisciplinary treatment algorithm applied to later patients. RESULTS: Of 21 patients, mean ± SD age was 16 ± 1.6 years and 11 (52%) were male. Of patients with complete presentation data, common symptoms were edema (84%), discoloration (58%), and pain (58%). Thrombophilia workup revealed one heterozygote for factor V Leiden, 2 patients with factor VIII elevation and 1 patient with mildly low antithrombin. The most recent 8 patients were treated according to an algorithm developed by a multidisciplinary working group through experience with the first 13 cases. All patients underwent a venogram, endovascular intervention (including 15 receiving catheter-directed thrombolysis), and operative ipsilateral thoracic outlet decompression (first rib resection, anterior scalenectomy, and venolysis). Postoperative complications included hemothorax (2), pneumothorax (1), and recurrent thrombosis (2). Follow up duration was 12 ± 9.5 months. Symptoms recurred transiently in 1 patient. CONCLUSION: Pediatric patients with PSS can be treated successfully using a multidisciplinary treatment algorithm including anticoagulation, catheter-directed thrombolysis, and operative decompression of the thoracic outlet. Early outcomes are promising.

Predictors of Enteral Autonomy in Children with Intestinal Failure: A Multicenter Cohort Study.

OBJECTIVES: In a large cohort of children with intestinal failure (IF), we sought to determine the cumulative incidence of achieving enteral autonomy and identify patient and institutional characteristics associated with enteral autonomy. STUDY DESIGN: A multicenter, retrospective cohort analysis from the Pediatric Intestinal Failure Consortium was performed. IF was defined as severe congenital or acquired gastrointestinal diseases during infancy with dependence on parenteral nutrition (PN) >60 days. Enteral autonomy was defined as PN discontinuation >3 months. RESULTS: A total of 272 infants were followed for a median (IQR) of 33.5 (16.2-51.5) months. Enteral autonomy was achieved in 118 (43%); 36 (13%) remained PN dependent and 118 (43%) patients died or underwent transplantation. Multivariable analysis identified necrotizing enterocolitis (NEC; OR 2.42, 95% CI 1.33-4.47), care at an IF site without an associated intestinal transplantation program (OR 2.73, 95% CI 1.56-4.78), and an intact ileocecal valve (OR 2.80, 95% CI 1.63-4.83) as independent risk factors for enteral autonomy. A second model (n = 144) that included only patients with intraoperatively measured residual small bowel length found NEC (OR 3.44, 95% CI 1.36-8.71), care at a nonintestinal transplantation center (OR 6.56, 95% CI 2.53-16.98), and residual small bowel length (OR 1.04 cm, 95% CI 1.02-1.06 cm) to be independently associated with enteral autonomy. CONCLUSIONS: A substantial proportion of infants with IF can achieve enteral autonomy. Underlying NEC, preserved ileocecal valve, and longer bowel length are associated with achieving enteral autonomy. It is likely that variations in institutional practices and referral patterns also affect outcomes in children with IF.

Preservation of biochemical liver function with low-dose soy-based lipids in children with intestinal failure-associated liver disease.

OBJECTIVES: Intestinal failure-associated liver disease (IFALD) contributes to significant morbidity in pediatric patients with intestinal failure (IF); however, the use of parenteral nutrition (PN) with a fish oil-based intravenous (IV) emulsion (FO) has been associated with biochemical reversal of cholestasis and improved outcomes. Unfortunately, FO increases the complexity of care: because it can be administered only under Food and Drug Administration compassionate use protocols requiring special monitoring, it is not available as a 3-in-1 solution and is more expensive than comparable soy-based IV lipid emulsion (SO). Because of these pragmatic constraints, a series of patient families were switched to low-dose (1 g kg(-1) day(-1)) SO following biochemical resolution of cholestasis. The present study examines whether reversal of cholestasis and somatic growth are maintained following this transition. METHODS: The present study is a chart review of all children with IFALD who switched from FO to SO following resolution of cholestasis. Variables are presented as medians (interquartile ranges). Comparisons were performed using the Wilcoxon signed-rank test. RESULTS: Seven patients ages 25.9 (16.2-43.2) months were transitioned to SO following reversal of cholestasis using FO. At a median follow-up of 13.9 (4.3-50.1) months, there were no significant differences between pretransition and post-transition serum alanine and aspartate aminotransferases, direct bilirubin, and weight-for-age z scores. Because of recurrence of cholestasis, 1 patient was restarted on FO after 4 months on SO. CONCLUSIONS: Biochemical reversal of IFALD and growth were preserved after transition from FO to SO in 6 of 7 (86%) patients. Given the challenges associated with the use of FO, SO may be a viable alternative in select patients with home PN.

Tight Glycemic Control With Insulin Does Not Affect Skeletal Muscle Degradation During the Early Postoperative Period Following Pediatric Cardiac Surgery.

OBJECTIVE: Critical illness is associated with significant catabolism, and persistent protein loss correlates with increased morbidity and mortality. Insulin is a potent anticatabolic hormone; high-dose insulin decreases skeletal muscle protein breakdown in critically ill pediatric surgical patients. However, insulin's effect on protein catabolism when given at clinically utilized doses has not been studied. The objective was to evaluate the effect of postoperative tight glycemic control and clinically dosed insulin on skeletal muscle degradation in children after cardiac surgery with cardiopulmonary bypass. DESIGN: Secondary analysis of a two-center, prospective randomized trial comparing tight glycemic control with standard care. Randomization was stratified by study center. PATIENTS: Children 0-36 months who were admitted to the ICU after cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS: In the tight glycemic control arm, insulin was titrated to maintain blood glucose between 80 and 110 mg/dL. Patients in the control arm received standard care. Skeletal muscle breakdown was quantified by a ratio of urinary 3-methylhistidine to urinary creatinine. MEASUREMENTS AND MAIN RESULTS: A total of 561 patients were included: 281 in the tight glycemic control arm and 280 receiving standard care. There was no difference in 3-methylhistidine to creatinine between groups (tight glycemic control, 249 ± 127 vs standard care, 253 ± 112, mean ± SD in µmol/g; p = 0.72). In analyses restricted to the patients in tight glycemic control arm, higher 3-methylhistidine to creatinine correlated with younger age, as well as lower weight, weight-for-age z score, length, and body surface area (p < 0.005 for each) and lower postoperative day 3 serum creatinine (r = -0.17; p = 0.02). Sex, prealbumin, and albumin were not associated with 3-methylhistidine to creatinine. During urine collection, 245 patients (87%) received insulin. However, any insulin exposure did not impact 3-methylhistidine to creatinine (t test, p = 0.45), and there was no dose-dependent effect of insulin on 3-methylhistidine to creatinine (r = -0.03; p = 0.60). CONCLUSION: Although high-dose insulin has an anabolic effect in experimental conditions, at doses necessary to achieve normoglycemia, insulin appears to have no discernible impact on skeletal muscle degradation in critically ill pediatric cardiac surgical patients.

Incidental Preduodenal Portal Vein Causing Partial Duodenal Obstruction and Hypertrophied Pre-Pyloric Gastric Polyp.

Preduodenal portal vein (PDPV) is a rare congenital anomaly in which the portal vein lies anterior to the duodenum rather than its normal posterior position. It is a known rare cause of duodenal obstruction and can be associated with other anomalies such as malrotation with or without jejunal atresia. Presented is an incidentally found PDPV causing partial duodenal obstruction during exploration for the resection of a gastric mass and placement of open gastrostomy tube for feeding. This was managed with duodenoduodenostomy, re-creating normal anatomy with portal.

Laparoscopic-Assisted Pancreatic Necrosectomy: Technique and Initial Outcomes.

BACKGROUND: Necrotizing pancreatitis (NP) may result de novo or following procedures such as ERCP or partial pancreatectomy (post-procedural), and may require surgical debridement. Video-assisted retroperitoneal debridement (VARD) is a standard approach for NP that employs a 5 cm incision with varying degrees of blind and open debridement. We describe our technique and outcomes of a modified VARD called laparoscopic-assisted pancreatic necrosectomy (LAPN) performed through a single 12 mm incision that uses direct laparoscopic visualization during debridement. METHODS: At one medical center, all LAPN patients (2012-2020) were assessed for demographics, disease factors, and outcomes. Bivariate logistic regression analyses were performed to identify factors independently associated with recovery after LAPN for patients with de novo vs post-procedural necrosum. RESULTS: Over 9 years, 60 patients underwent LAPN for NP. Median age was 57 years (IQR: 47-66) and 43 (69%) were men. Pancreas necrosum was de novo in 39 (63%) patients and post-procedural in 23 (37%). NP resolved with a median of 1 LAPN procedure and median hospitalization was 33 days. The LAPN major morbidity rate and in-hospital mortality rate were 47% and 5%. No significant differences were seen between NP etiology cohorts, although post-procedure NP patients trended towards a faster clinical recovery to baseline compared to de novo patients (193 vs 394 days; p-value = .07). CONCLUSIONS: LAPN offers a smaller incision with excellent visualization and non-inferior outcomes, regardless of etiology, with likely faster recovery for patients with post-procedural vs de novo necrotizing pancreatitis.

Surgical Management of Ulcerative Colitis in Children and Adolescents: A Systematic Review from the APSA Outcomes and Evidence-Based Practice Committee.

INTRODUCTION: The incidence of ulcerative colitis (UC) is increasing. Roughly 20% of all patients with UC are diagnosed in childhood, and children typically present with more severe disease. Approximately 40% will undergo total colectomy within ten years of diagnosis. The objective of this study is to assess the available evidence regarding the surgical management of pediatric UC as determined by the consensus agreement of the American Pediatric Surgical Association Outcomes and Evidence-Based Practice Committee (APSA OEBP). METHODS: Through an iterative process, the membership of the APSA OEBP developed five a priori questions focused on surgical decision-making for children with UC. Questions focused on surgical timing, reconstruction, use of minimally invasive techniques, need for diversion, and risks to fertility and sexual function. A systematic review was conducted, and articles were selected for review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Risk of Bias was assessed using Methodological Index for Non-Randomized Studies (MINORS) criteria. The Oxford Levels of Evidence and Grades of Recommendation were utilized. RESULTS: A total of 69 studies were included for analysis. Most manuscripts contain level 3 or 4 evidence from single-center retrospective reports, leading to a grade D recommendation. MINORS assessment revealed a high risk of bias in most studies. J-pouch reconstruction may result in fewer daily stools than straight ileoanal anastomosis. There are no differences in complications based on the type of reconstruction. The timing of surgery should be individualized to patients and does not affect complications. Immunosuppressants do not appear to increase surgical site infection rates. Laparoscopic approaches result in longer operative times but shorter lengths of stay and fewer small bowel obstructions. Overall, complications are not different using an open or minimally invasive approach. CONCLUSIONS: There is currently low-level evidence related to certain aspects of surgical management for UC, including timing, reconstruction type, use of minimally invasive techniques, need for diversion, and risks to fertility and sexual function. Multicenter, prospective studies are recommended to better answer these questions and ensure the best evidence-based care for our patients. LEVEL OF EVIDENCE: Level of evidence III. STUDY TYPE: Systematic review.

Improving care through standardized treatment of spontaneous pneumothorax.

PURPOSE: The objective of this quality improvement (QI) initiative was to implement a standardized clinical treatment protocol for patients presenting with primary spontaneous pneumothorax (PSP) in order to decrease hospital length of stay (LOS), diagnostic radiation exposure, and related cost. METHODS: Baseline data from patients admitted with PSP from January 1, 2016 to July 31, 2018 were compared to data from patients managed using a newly developed evidence-based treatment pathway from August 1, 2018 to December 31, 2019. Standard QI methodology was used to track results. RESULTS: Fifty-six episodes of PSP were observed during the baseline period and 40 episodes of PSP following initiation of the PSP protocol. The average LOS decreased from 4.5 days to 2.9 days. Patients underwent an average of 8.8 X-rays per admission preintervention versus 5.9 postintervention. The rate of CT scans decreased from 45% to 15% (p = 0.002). There was no significant difference in the rates of 30-day recurrence between the preintervention (13%) and postintervention (10%) groups (p = 0.7). Average admission costs per patient decreased by $1322 after adoption of the pathway. CONCLUSIONS: Adoption of a standardized treatment protocol for PSP led to a reduction in LOS, diagnostic imaging utilization, and cost without increasing clinical recurrence. TYPE OF STUDY: Quality improvement. LEVEL OF EVIDENCE: Level III.

An unexpected case of Lyme disease in a soldier serving in northern Iraq.

Lyme disease is a tick-transmitted disease caused by the spirochete Borrelia burgdorferi. Cases have been reported across the United States, Canada, and Europe. Additional cases have been described in other parts of the world including Japan, Mexico, and Turkey. We report an unexpected case of Lyme disease from Iraq.

Suction Rectal Biopsy is Accurate in Late Preterm Infants with Suspected Hirschsprung Disease.

BACKGROUND: Few data are available to substantiate the dogma commonly held by pediatric surgeons and pediatric pathologists that rectal biopsies may be inaccurate or risky in preterm neonates. We aimed to address these concerns. METHODS: We performed a single-institution retrospective review of patients who underwent suction rectal biopsies at <37 weeks corrected age from 2009 to 2018. The primary outcomes were accuracy of biopsy results and procedural complications. RESULTS: Forty-nine patients underwent suction rectal biopsy at <37 weeks corrected age. Mean gestational age at biopsy was 35.2 weeks (range 32.1-36.9) and mean weight was 2126 g (range 1590-3100). Five (10%) infants had biopsies positive for Hirschsprung Disease. All 5 later underwent pull-through operations and had pathologic confirmation of an aganglionic segment. The remaining 44 (90%) had biopsies showing ganglion cells. None were later found to have HD during the follow up period. Those who underwent biopsy at <2000 g (16/44) had 100% sensitivity [95% CI 48, 100] and specificity [95% CI 92, 100] (2 true positives, 14 true negatives). There were no complications identified. CONCLUSION: Suction rectal biopsy can be performed safely in preterm infants as small as 1590-2000 g with high accuracy. Clinicians should not hesitate to perform a biopsy for a premature infant when clinically appropriate. TYPE OF STUDY: Study of a diagnostic test. LEVEL OF EVIDENCE: Level IV.

The pediatric surgery match by the numbers: Defining the successful application.

BACKGROUND: Pediatric surgery remains the most competitive general surgery subspecialty. The authors suspected significant inflation in academic metrics since the last published paper. This study aimed to identify factors associated with applicant success in the match. METHODS: After IRB approval, all applications to a single accredited pediatric surgery fellowship program were reviewed for match years 2014-2018. Matched and unmatched applicants were compared in an unadjusted and adjusted analysis. RESULTS: This training program received 414 of 425 total applications (97%). Match results were available for 388 (94%). Matched applicants were more likely to train in programs with pediatric surgery fellowships (64% vs. 28%) and to have dedicated research time (55% vs. 21%; all p < 0.01). Matched applicants had more total publications (median: 12 vs. 7, p < 0.01) and higher ABSITE scores (median: 64th vs. 59th percentile, p < 0.01). Training in multiple programs negatively impacted the chance to match (p < 0.01). The median number of publications per applicant increased over the study time period from 7 to 11 (p < 0.01). CONCLUSIONS: The likelihood of matching into a pediatric surgery fellowship was related to the type of residency attended, dedicated research time, ABSITE scores, and number of publications. Overall, the total number of publications reported by all applicants increased. TYPE OF STUDY: Retrospective Comparative Study. LEVEL OF EVIDENCE: Level III.