Surgery for Crohn's Disease Is Associated with a Dysbiotic Microbiome and Metabolome: Results from Two Prospective Cohorts.

BACKGROUND AND AIMS: Crohn's disease is associated with alterations in the gut microbiome and metabolome described as dysbiosis. We characterized the microbial and metabolic consequences of ileal resection, the most common Crohn's disease surgery. METHODS: Patients with and without intestinal resection were identified from the Diet to Induce Remission in Crohn's Disease and Study of a Prospective Adult Research Cohort with Inflammatory Bowel Disease studies. Stool samples were analyzed with shotgun metagenomics sequencing. Fecal butyrate was measured with 1H nuclear magnetic resonance spectroscopy. Fecal bile acids and plasma 7α-hydroxy-4-cholesten-3-one (C4) was measured with mass spectrometry. RESULTS: Intestinal resection was associated with reduced alpha diversity and altered beta diversity with increased Proteobacteria and reduced Bacteroidetes and Firmicutes. Surgery was associated with higher representation of genes in the KEGG pathway for ABC transporters and reduction in genes related to bacterial metabolism. Surgery was associated with reduced concentration of the But gene but this did not translate to reduced fecal butyrate concentration. Surgery was associated with decreased abundance of bai operon genes, with increased plasma C4 concentration, increased primary bile acids and reduced secondary bile acids, including isoLCA. Additionally, E lenta, A equalofaciens and G pamelaeae were lower in abundance among patients with prior surgery in both cohorts. CONCLUSIONS: In two different populations, prior surgery in Crohn's disease is associated with altered fecal microbiome. Patients who had undergone ileal resection had reduction in the potentially beneficial bacteria E lenta and related actinobacteria as well as secondary bile acids, including isoLCA, suggesting that these could be biomarkers of patients at higher risk for disease progression.

The evolutionarily ancient FOXA transcription factors shape the murine gut microbiome via control of epithelial glycosylation.

Evolutionary adaptation of multicellular organisms to a closed gut created an internal microbiome differing from that of the environment. Although the composition of the gut microbiome is impacted by diet and disease state, we hypothesized that vertebrates promote colonization by commensal bacteria through shaping of the apical surface of the intestinal epithelium. Here, we determine that the evolutionarily ancient FOXA transcription factors control the composition of the gut microbiome by establishing favorable glycosylation on the colonic epithelial surface. FOXA proteins bind to regulatory elements of a network of glycosylation enzymes, which become deregulated when Foxa1 and Foxa2 are deleted from the intestinal epithelium. As a direct consequence, microbial composition shifts dramatically, and spontaneous inflammatory bowel disease ensues. Microbiome dysbiosis was quickly reversed upon fecal transplant into wild-type mice, establishing a dominant role for the host epithelium, in part mediated by FOXA factors, in controlling symbiosis in the vertebrate holobiont.

Adequate bone healing after supplementary fixation of periprosthetic total knee arthroplasty fractures using Luque cerclage wiring: a retrospective case series.

PURPOSE: Cerclage wiring is a well-known supplemental fixation technique that can be used in many types of fractures. With the tendency toward minimally invasive approaches in the management of periprosthetic total knee arthroplasty (TKA) fractures, and with absence of a dedicated study that reports the results of cerclage wiring in TKA fractures in particular, the aim of this retrospective study is to report the outcomes of supplementary cerclage wiring using simple Luque wires in fractures of distal femur associated with TKA. METHOD: Eighteen cases, with a mean age of 77.2 years had complete follow-up data and had their radiographs and clinical data assessed for this study. Patients received cerclage wiring along with plates, retrograde nailing or around cracked femoral shaft overlying revision TKA femoral stem during the surgical management of periprosthetic TKA distal femur fractures. RESULTS: Fracture healing with adequate callus formation occurred in all 18 cases at a mean of 11.4 weeks postoperatively. None of the cases had any vascular injury, and after a mean clinical follow-up of 51 weeks, none of the cases had nonunion or hardware complications. One case had postoperative periprosthetic infection that developed 8 months after full fracture healing and had a two-stage revision using revision stemmed TKA and protective cerclage wiring with successful eradication of infection. CONCLUSION: Supplementary cerclage wiring in distal femur TKA fractures can aid in enhanced bone healing with minimal complications, provided that adequate reduction and rigid fixation were achieved. This study reflects the level of evidence IV.

A high-resolution transcriptomic and spatial atlas of cell types in the whole mouse brain.

The mammalian brain consists of millions to billions of cells that are organized into many cell types with specific spatial distribution patterns and structural and functional properties1-3. Here we report a comprehensive and high-resolution transcriptomic and spatial cell-type atlas for the whole adult mouse brain. The cell-type atlas was created by combining a single-cell RNA-sequencing (scRNA-seq) dataset of around 7 million cells profiled (approximately 4.0 million cells passing quality control), and a spatial transcriptomic dataset of approximately 4.3 million cells using multiplexed error-robust fluorescence in situ hybridization (MERFISH). The atlas is hierarchically organized into 4 nested levels of classification: 34 classes, 338 subclasses, 1,201 supertypes and 5,322 clusters. We present an online platform, Allen Brain Cell Atlas, to visualize the mouse whole-brain cell-type atlas along with the single-cell RNA-sequencing and MERFISH datasets. We systematically analysed the neuronal and non-neuronal cell types across the brain and identified a high degree of correspondence between transcriptomic identity and spatial specificity for each cell type. The results reveal unique features of cell-type organization in different brain regions-in particular, a dichotomy between the dorsal and ventral parts of the brain. The dorsal part contains relatively fewer yet highly divergent neuronal types, whereas the ventral part contains more numerous neuronal types that are more closely related to each other. Our study also uncovered extraordinary diversity and heterogeneity in neurotransmitter and neuropeptide expression and co-expression patterns in different cell types. Finally, we found that transcription factors are major determinants of cell-type classification and identified a combinatorial transcription factor code that defines cell types across all parts of the brain. The whole mouse brain transcriptomic and spatial cell-type atlas establishes a benchmark reference atlas and a foundational resource for integrative investigations of cellular and circuit function, development and evolution of the mammalian brain.

Successful Primary Treatment of Ankle Fractures in Diabetic Patients with Peripheral Neuropathy Using a Tibiotalocalcaneal Nail: A Case Series.

Background: Among diabetics, patients with peripheral neuropathy are at increased risk of developing complications following an ankle fracture. While the outcomes in these patients treated nonoperatively have been poor, the outcomes in those undergoing open reduction and internal fixation are at the best modest. We hypothesize that closed reduction and internal fixation with tibiotalocalcaneal nail is an effective primary procedure in this complication prone patient group. Methods: A retrospective review of diabetic patients with peripheral neuropathy who underwent acute treatment of an ankle fracture with closed reduction and internal fixation with a tibiotalocalcaneal nail at two Level 1 trauma centers was performed. 30 patients were identified and divided into 2 groups with respect to their postoperative weight bearing protocol: 20 patients in the early weight bearing (EWB) group and 10 patients in the touch-down weight bearing (TDWB). The primary outcome was the rate of return to baseline function and the secondary outcomes included the incidence of wound dehiscence, wound infection, implant failure, loss of fixation, loss of reduction and amputation. Results: In the EWB group, 15/20 patients returned to their baseline function, 5/20 had wound dehiscence and infection, 2/20 had implant failure, 5/20 had loss of fixation, 4/20 had loss of reduction, and 4/20 underwent amputation. In the TDWB group, 9/10 patients returned to their baseline function, 1/10 had implant failure, 1/10 had loss of fixation. No patients from this group had loss of reduction or underwent amputation. Conclusion: Treatment with tibiotalocalcaneal nail is an effective primary procedure in this complication prone group of patients, assuming that weight bearing is delayed for six weeks to protect soft tissues and surgical incisions. Level of Evidence: Level IV, retrospective case series.

Administration of Bifidobacterium animalis subsp. lactis strain BB-12® in healthy children: characterization, functional composition, and metabolism of the gut microbiome.

Introduction: The consumption of probiotics may influence children's gut microbiome and metabolome, which may reflect shifts in gut microbial diversity composition and metabolism. These potential changes might have a beneficial impact on health. However, there is a lack of evidence investigating the effect of probiotics on the gut microbiome and metabolome of children. We aimed to examine the potential impact of a two (Streptococcus thermophilus and Lactobacillus delbrueckii; S2) vs. three (S2 + Bifidobacterium animalis subsp. lactis strain BB-12) strain-supplemented yogurt. Methods: Included in this study were 59 participants, aged one to five years old, recruited to phase I of a double-blinded, randomized controlled trial. Fecal samples were collected at baseline, after the intervention, and at twenty days post-intervention discontinuation, and untargeted metabolomics and shotgun metagenomics were performed. Results: Shotgun metagenomics and metabolomic analyses showed no global changes in either intervention group's gut microbiome alpha or beta diversity indices, except for a lower microbial diversity in the S2 + BB12 group at Day 30. The relative abundance of the two and three intervention bacteria increased in the S2 and S2 + BB12 groups, respectively, from Day 0 to Day 10. In the S2 + BB12 group, the abundance of several fecal metabolites increased at Day 10, including alanine, glycine, lysine, phenylalanine, serine, and valine. These fecal metabolite changes did not occur in the S2 group. Discussion: In conclusion, there were were no significant differences in the global metagenomic or metabolomic profiles between healthy children receiving two (S2) vs. three (S2 + BB12) probiotic strains for 10 days. Nevertheless, we observed a significant increase (Day 0 to Day 10) in the relative abundance of the two and three probiotics administered in the S2 and S2 + BB12 groups, respectively, indicating the intervention had a measurable impact on the bacteria of interest in the gut microbiome. Future research using longer probiotic intervention durations and in children at risk for gastrointestinal disorders may elucidate if functional metabolite changes confer a protective gastrointestinal effect.

Context matters for disability and priority setting for musculoskeletal diseases: revisiting the egalitarian approach to disability weights and disability-adjusted life-years.

Health metrics have evolved with increasing sophistication. The disability-adjusted life-year (DALY) has emerged as a widely used metric. While DALYs vary between countries, the global disability weights (DWs) that are integral to the DALY ignore the potential impact of local factors on the burden of disease. Developmental dysplasia of the hip (DDH), a spectrum of hip pathologies, typically develops during early childhood and is a leading cause of early hip osteoarthritis. This paper explores the variability in the DW for DDH in relation to to local health environments using select health system indicators.The DW for DDH increases with decreasing income level of countries. The Human Development Index and the Gross Domestic Product per capita are both negatively correlated with (p<0.05) the DW for DDH per country. For the indicators surgical workforce, surgical procedures and hospital beds per 1000 population, there is a significant negative correlation in countries not meeting the minimum standard of that indicator (p<0.05), while for countries meeting that minimum standard, the correlation between DW for DDH and the respective indicator is not significantly different from zero.Consideration should be given to re-establishing the DWs for health entities in countries that do not meet the minimum standards of a functional health system. This would more accurately reflect the burden of disease from a functional perspective in LMICs, and perhaps allow for more informed priority setting within LMICs and for donors. The establishment of these DWs should not start from scratch; our data suggest that the variability in DWs due to context can most likely be modelled using health system and financial protection indicators already in use today.

Lacticaseibacillus rhamnosus Strain GG (LGG) Regulate Gut Microbial Metabolites, an In Vitro Study Using Three Mature Human Gut Microbial Cultures in a Simulator of Human Intestinal Microbial Ecosystem (SHIME).

In the present research, we investigated changes in the gut metabolome that occurred in response to the administration of the Laticaseibacillus rhamnosus strain GG (LGG). The probiotics were added to the ascending colon region of mature microbial communities established in a human intestinal microbial ecosystem simulator. Shotgun metagenomic sequencing and metabolome analysis suggested that the changes in microbial community composition corresponded with changes to metabolic output, and we can infer linkages between some metabolites and microorganisms. The in vitro method permits a spatially-resolved view of metabolic transformations under human physiological conditions. By this method, we found that tryptophan and tyrosine were mainly produced in the ascending colon region, while their derivatives were detected in the transverse and descending regions, revealing sequential amino acid metabolic pathways along with the colonic tract. The addition of LGG appeared to promote the production of indole propionic acid, which is positively associated with human health. Furthermore, the microbial community responsible for the production of indole propionic acid may be broader than is currently known.

Addition of cariogenic pathogens to complex oral microflora drives significant changes in biofilm compositions and functionalities.

BACKGROUND: Dental caries is a microbe and sugar-mediated biofilm-dependent oral disease. Of particular significance, a virulent type of dental caries, known as severe early childhood caries (S-ECC), is characterized by the synergistic polymicrobial interaction between the cariogenic bacterium, Streptococcus mutans, and an opportunistic fungal pathogen, Candida albicans. Although cross-sectional studies reveal their important roles in caries development, these exhibit limitations in determining the significance of these microbial interactions in the pathogenesis of the disease. Thus, it remains unclear the mechanism(s) through which the cross-kingdom interaction modulates the composition of the plaque microbiome. Here, we employed a novel ex vivo saliva-derived microcosm biofilm model to assess how exogenous pathogens could impact the structural and functional characteristics of the indigenous native oral microbiota. RESULTS: Through shotgun whole metagenome sequencing, we observed that saliva-derived biofilm has decreased richness and diversity but increased sugar-related metabolism relative to the planktonic phase. Addition of S. mutans and/or C. albicans to the native microbiome drove significant changes in its bacterial composition. In addition, the effect of the exogenous pathogens on microbiome diversity and taxonomic abundances varied depending on the sugar type. While the addition of S. mutans induced a broader effect on Kyoto Encyclopedia of Genes and Genomes (KEGG) ortholog abundances with glucose/fructose, S. mutans-C. albicans combination under sucrose conditions triggered unique and specific changes in microbiota composition/diversity as well as specific effects on KEGG pathways. Finally, we observed the presence of human epithelial cells within the biofilms via confocal microscopy imaging. CONCLUSIONS: Our data revealed that the presence of S. mutans and C. albicans, alone or in combination, as well as the addition of different sugars, induced unique alterations in both the composition and functional attributes of the biofilms. In particular, the combination of S. mutans and C. albicans seemed to drive the development (and perhaps the severity) of a dysbiotic/cariogenic oral microbiome. Our work provides a unique and pragmatic biofilm model for investigating the functional microbiome in health and disease as well as developing strategies to modulate the microbiome. Video Abstract.

A high-resolution transcriptomic and spatial atlas of cell types in the whole mouse brain.

The mammalian brain is composed of millions to billions of cells that are organized into numerous cell types with specific spatial distribution patterns and structural and functional properties. An essential step towards understanding brain function is to obtain a parts list, i.e., a catalog of cell types, of the brain. Here, we report a comprehensive and high-resolution transcriptomic and spatial cell type atlas for the whole adult mouse brain. The cell type atlas was created based on the combination of two single-cell-level, whole-brain-scale datasets: a single-cell RNA-sequencing (scRNA-seq) dataset of ~7 million cells profiled, and a spatially resolved transcriptomic dataset of ~4.3 million cells using MERFISH. The atlas is hierarchically organized into five nested levels of classification: 7 divisions, 32 classes, 306 subclasses, 1,045 supertypes and 5,200 clusters. We systematically analyzed the neuronal, non-neuronal, and immature neuronal cell types across the brain and identified a high degree of correspondence between transcriptomic identity and spatial specificity for each cell type. The results reveal unique features of cell type organization in different brain regions, in particular, a dichotomy between the dorsal and ventral parts of the brain: the dorsal part contains relatively fewer yet highly divergent neuronal types, whereas the ventral part contains more numerous neuronal types that are more closely related to each other. We also systematically characterized cell-type specific expression of neurotransmitters, neuropeptides, and transcription factors. The study uncovered extraordinary diversity and heterogeneity in neurotransmitter and neuropeptide expression and co-expression patterns in different cell types across the brain, suggesting they mediate a myriad of modes of intercellular communications. Finally, we found that transcription factors are major determinants of cell type classification in the adult mouse brain and identified a combinatorial transcription factor code that defines cell types across all parts of the brain. The whole-mouse-brain transcriptomic and spatial cell type atlas establishes a benchmark reference atlas and a foundational resource for deep and integrative investigations of cell type and circuit function, development, and evolution of the mammalian brain.

An analysis of cost and complications for patients sustaining a second, contralateral hip fracture within 1 year.

INTRODUCTION: Hip fractures are an increasingly common occurrence among the aging population. With increased life expectancy and advancements in medicine, patients sustaining a hip fracture are at an increasing risk of sustaining a contralateral hip fracture. Efforts are being made to better understand the environment of these hip fractures so that secondary prevention clinics and guidelines can be made to help prevent recurrent osteoporotic hip fractures. The estimated incidence of a contralateral hip fracture varies from 2 to 10% and is reportedly associated with a higher incidence of complications. Previous studies evaluating contralateral hip fractures compared a single cohort of patients sustaining a second hip fracture with patients who sustained only one hip fracture. We aimed to investigate the overall complications and associated costs as it relates to a patients first hip fracture and contrast this to the same patient's contralateral, second hip fractures. METHODS: We performed a retrospective review of all patients in our health systems electronic database who were found to have surgically treated hip fractures between January 2004 and July 2019. Patients with surgically treated hip fractures (CPT Codes: 27235, 27236, 27245, 27244), who sustained a second contralateral hip fracture were included. Medical complications within 30 days of either procedure (such as pneumonia, UTI, altered mental status and others), length of stay, orthopedic complications (such as wound complications, infection, hardware failure, nonunion), type of implants, costs, comorbidities, and ASA Class as well as Mortality were reviewed. RESULTS: A total of 4,870 hip fractures were identified during the study period where 137 (2.8%) patients sustained a second hip fracture, and 47 (0.9%) of which were sustained within the first year after their index hip fracture. There was no statistical difference in length of stay (p = 0.68), medical (p>0.99) or orthopedic complications (p>0.99) between patients first and second hip fractures. There was an increased incidence of cognitive impairment with the second hip fracture (P = 0.0002). For patients that underwent operative treatment of a second hip fracture, the total cost of care was higher for the second surgery (mean difference 757. 38 USD) however the difference wasn't statistically significant (p = 0.31). The overall 1-year mortality rate was 14.9 percent. CONCLUSIONS: Our study demonstrates there is no statistical difference between the first and second surgery regarding length of stay, medical or orthopedic complications and cost.

On the complex and dimensional relationship of maternal posttraumatic stress disorder during early childhood and child outcomes at school-age.

BACKGROUND: Several studies have shown associations between maternal interpersonal violence-related posttraumatic stress disorder (PTSD), child mental health problems, and impaired socioemotional development. However, the existing literature lacks evidence linking constellations of risk factors such as maternal interpersonal-violence-related PTSD, psychopathology, and interactive behavior with toddlers and outcome measures at school-age. METHODS: This study involved a prospective, longitudinal investigation of 62 mothers and examined the relationship between maternal variables measured when children were in early childhood (mean age 27 months), and child outcomes when children were school-age (age mean = 83.2 months) while retaining a focus on the context of maternal PTSD. To identify and weigh associated dimensions comparatively, we employed sparse canonical correlation analysis (sCCA) aimed at associating dimensions of a dataset of 20 maternal variables in early childhood with that of more than 20 child outcome variables (i.e., child psychopathology, life-events, and socioemotional skills) at school-age. RESULTS: Phase 1 variables with the highest weights were those of maternal psychopathology: PTSD, depressive and dissociative symptoms, and self-report of parental stress. The highest weighted Phase 2 child outcome measures were those of child psychopathology: PTSD, anxiety, and depressive symptoms as well as peer bullying and victimization. CONCLUSIONS: sCCA revealed that trauma-related concepts in mothers were significantly and reliably associated with child psychopathology and other indicators of risk for intergenerational transmission of violence and victimization. The results highlight the dimensional and multifaceted nature-both for mothers as well as children-of the intergenerational transmission of violence and associated psychopathology.

Distinct community structures of the fungal microbiome and respiratory health in adults with cystic fibrosis.

BACKGROUND: The respiratory tract fungal microbiome in cystic fibrosis (CF) has been understudied despite increasing recognition of fungal pathogens in CF lung disease. We sought to better understand the fungal communities in adults with CF, and to define relationships between fungal profiles and clinical characteristics. METHODS: We enrolled 66 adults with CF and collected expectorated sputum, spirometry, Cystic Fibrosis Questionnaire-revised, and clinical data. Fungi were molecularly profiled by sequencing of the internal transcribed spacer (ITS) region. Total fungal abundance was measured by quantitative PCR. Relative abundance and qPCR-corrected abundances were determined. Selective fungus culture identified cultivable fungi. Alpha diversity and beta diversity were measured and relationships with clinical parameters were interrogated. RESULTS: Median age was 29 years and median FEV1 percent predicted 58%. Members of the Candida genus were the most frequent dominant taxa in CF sputum. Apiotrichum, Trichosporon, Saccharomyces cerevisiae, and Scedosporium were present in high relative abundance in few samples; whereas, Aspergillus species were detected at low levels. Higher FEV1% predicted and CFTR modulator use were associated with greater alpha-diversity. Chronic azithromycin use was associated with lower alpha-diversity. Patients with acute pulmonary had distinct fungal community composition compared to clinically stable subjects. Differing yeast species were mainly responsible for the community differences. CONCLUSION: The respiratory tract fungal microbiome in adults with CF is associated with lung function, pulmonary exacerbation status, macrolide use, and CFTR modulator use. Future work to better understand fungal diversity in the CF airway and its impact on lung health is necessary.

Administration of Bifidobacterium animalis subsp. lactis Strain BB-12 ® in Healthy Children: Characterization, Functional Composition, and Metabolism of the Gut Microbiome.

The consumption of probiotics may influence children's gut microbiome and metabolome, which may reflect shifts in gut microbial diversity composition and metabolism. These potential changes might have a beneficial impact on health. However, there is a lack of evidence investigating the effect of probiotics on the gut microbiome and metabolome of children. We aimed to examine the potential impact of a two ( Streptococcus thermophilus and Lactobacillus delbrueckii ; S2) vs . three (S2 + Bifidobacterium animalis subsp. lactis strain BB-12) strain-supplemented yogurt. Included in this study were 59 participants, aged one to five years old, recruited to phase I of a double-blinded, randomized controlled trial. Fecal samples were collected at baseline, after the intervention, and at twenty days post-intervention discontinuation, and untargeted metabolomics and shotgun metagenomics were performed. Shotgun metagenomics and metabolomic analyses showed no global changes in either intervention group's gut microbiome alpha or beta diversity indices. The relative abundance of the two and three intervention bacteria increased in the S2 and S2 + BB12 groups, respectively, from Day 0 to Day 10 . In the S2+BB12 group, the abundance of several fecal metabolites was reduced at Day 10 , including alanine, glycine, lysine, phenylalanine, serine, and valine. These fecal metabolite changes did not occur in the S2 group. Future research using longer probiotic intervention durations and in children at risk for gastrointestinal disorders may elucidate if functional metabolite changes confer a protective gastrointestinal effect.

The microbiome stabilizes circadian rhythms in the gut.

The gut microbiome is well known to impact host physiology and health. Given widespread control of physiology by circadian clocks, we asked how the microbiome interacts with circadian rhythms in the Drosophila gut. The microbiome did not cycle in flies fed ad libitum, and timed feeding (TF) drove limited cycling only in clockless per01 flies. However, TF and loss of the microbiome influenced the composition of the gut cycling transcriptome, independently and together. Moreover, both interventions increased the amplitude of rhythmic gene expression, with effects of TF at least partly due to changes in histone acetylation. Contrary to expectations, timed feeding rendered animals more sensitive to stress. Analysis of microbiome function in circadian physiology revealed that germ-free flies reset more rapidly with shifts in the light:dark cycle. We propose that the microbiome stabilizes cycling in the host gut to prevent rapid fluctuations with changing environmental conditions.

An Interval Look at the Transplant Surgery Pipeline: Insights from General Surgery Residents' Operative Experience Using ACGME Operative Logs from 2000 to 2021.

OBJECTIVE: Given the declining number of US graduates pursuing transplant surgery as well as regulatory changes regarding transplant rotations for surgical residents, this study examined the transplant surgery operative volume of residents over the past 20 years. DESIGN: Retrospective analysis of the ACGME database of general surgery operative logs from academic year (AY) 1999-2000 to AY 2020-2021; data was categorized into time periods relative to regulatory changes: Period 1 (1999-2010) and Period 2 (2011-2021). SETTING/PARTICIPANTS: All ACGME-accredited general surgery residency programs in the US. FINDINGS: On average, the proportion of transplant cases to all total major cases was about 1% and did not change during the study period (p=0.61). Each graduating resident completed an average of 10.0 ± 11.0 cases during Period 1 and 10.8 ± 12.0 cases during Period 2, representing a statistically but unlikely clinically significant increase (p=0.008). Renal transplants comprised more than 50% of each resident's operative experience in transplant surgery. The proportion of resident involvement in all renal and liver transplantations nationally did not change during the study period, ranging from 34.5-42.9% for renal and 13.8-22.4% for liver. CONCLUSIONS: Resident volume in transplant surgery has largely remained consistent over the past 20 years, suggesting that changes in operative volume are unlikely driving declining interest in transplant surgery fellowship among US trainees.

Preterm infants at low risk for early-onset sepsis differ in early fecal microbiome assembly.

Antibiotics are administered near-universally to very low birth weight (VLBW) infants after birth for suspected early-onset sepsis (EOS). We previously identified a phenotypic group of VLBW infants, referred to as low-risk for EOS (LRE), whose risk of EOS is low enough to avoid routine antibiotic initiation. In this cohort study, we compared 18 such infants with 30 infants categorized as non-LRE to determine if the lower risk of pathogen transmission at birth is accompanied by differences in microbiome acquisition and development. We did shotgun metagenomic sequencing of 361 fecal samples obtained serially. LRE infants had a higher human-to-bacterial DNA ratio than non-LRE infants in fecal samples on days 1-3 after birth, confirming lower bacterial acquisition among LRE infants. The microbial diversity and composition in samples from days 4-7 differed between the groups with a predominance of Staphylococcus epidermidis in LRE infants and Enterobacteriaceae sp. in non-LRE infants. Compositional differences were congruent with the distribution of virulence factors and antibiotic resistant genes. After the first week, the overall composition was similar, but changes in relative abundance for several taxa with increasing age differed between groups. Of the nine late-onset bacteremia episodes, eight occurred in non-LRE infants. Species isolated from the blood culture was detected in the pre-antibiotic fecal samples of the infant for all episodes, though these species were also found in infants without bacteremia. In conclusion, LRE infants present a distinct pattern of microbiome development that is aligned with their low risk for EOS. Further investigation to determine the impact of these differences on later outcomes such as late-onset bacteremia is warranted.

Nontraumatic Spinal Cord Injury: Epidemiology, Etiology and Management.

The spinal cord is a conduit within the central nervous system (CNS) that provides ongoing communication between the brain and the rest of the body, conveying complex sensory and motor information necessary for safety, movement, reflexes, and optimization of autonomic function. After a traumatic spinal cord injury (SCI), supraspinal influences on the peripheral nervous system and autonomic nervous system (ANS) are disrupted, leading to spastic paralysis, sympathetic blunting, and parasympathetic dominance, resulting in cardiac dysrhythmias, systemic hypotension, bronchoconstriction, copious respiratory secretions, and uncontrolled bowel, bladder, and sexual dysfunction. This article outlines the pathophysiology of the less reported nontraumatic SCI (NTSCI), its classification, its influence on sensory/motor function, and introduces the probable comorbidities associated with SCI that will be discussed in more detail in the accompanying manuscripts of this special issue. Finally, management strategies for NTSCI will be provided.