Custom Endoprosthesis-Assisted Pediatric Microsurgical Jaw Reconstruction.

Surgical treatment of pediatric maxillary and mandibular tumors can cause significant postresection disfigurement, mastication, and speech dysfunction. The need to restore form and function without compromising growth at the recipient and donor sites poses a particular reconstructive dilemma. This study evaluates outcomes of the custom endoprosthesis (CE) compared with noncustom reconstruction (NCR) and introduces an algorithm using CE to optimize available soft tissue reconstructive options. An Institutional Review Board-approved retrospective review of all patients undergoing maxillary or mandibular reconstruction between 2016 and 2022 was completed. The independent variable of interest was CE utilization. Primary outcomes of interest included hardware failure/removal or exposure, major complications, and revision surgeries. Covariates of interest included patient demographics, medical comorbidities, tumor size, and pathologic diagnosis. Statistical analyses including independent t test, χ2 analyses, and univariate/multivariate logistic regression were performed using RStudio version 4.2.1. Fifty-one patients (37 mandible and 14 maxilla) underwent CE or NCR. Of patients, 37% (n = 19) received CE. Of patients who underwent mandibular reconstruction, there were significantly lower rates of hardware exposure (14.3% versus 47.8%, P = 0.018), failure (7.1% versus 43.5%, P = 0.048), major complications (28.6% versus 78.2%, P = 0.008), and revisions (11.1% versus 50.0%, P = 0.002) in the CE cohort compared with the NCR cohort. The rates of hardware failure, exposure, major complications, and revisions did not significantly differ in maxillary reconstructions, however, CE successfully reconstructed significantly larger defects (179.5 versus 74.6 cm3, P = 0.020) than NCRs. Deviating from NCR, the authors propose an algorithm considering anatomical location, extent of resection, and patient age for soft tissue selection. This algorithm yielded improved mandibular reconstructive outcomes and no increase in complications rate in maxillary reconstruction despite larger resection defects. Furthermore, the authors' initial findings demonstrate that CE is a safe option for pediatric maxillary and mandibular reconstruction that may, in addition, facilitate improved form and function.

PD-L1 and PD-1 Are Associated with Clinical Outcomes and Alveolar Immune Cell Activation in ARDS.

The relationship between the Programmed Death-Ligand 1 (PD-L1)/Programmed Death-1 (PD-1) pathway, lung inflammation, and clinical outcomes in acute respiratory distress syndrome (ARDS) is poorly understood. We sought to determine whether PD-L1/PD-1 in the lung or blood is associated with ARDS and associated severity. We measured soluble PD-L1 (sPD-L1) in plasma and lower respiratory tract samples (ARDS1 (n = 59) and ARDS2 (n = 78)) or plasma samples alone (ARDS3 (n = 149)) collected from subjects with ARDS and tested for associations with mortality using multiple regression. We used mass cytometry to measure PD-L1/PD-1 expression and intracellular cytokine staining in cells isolated from bronchoalveolar lavage fluid (BALF) (n = 18) and blood (n = 16) from critically-ill subjects with or without ARDS enrolled from a fourth cohort. Higher plasma levels of sPD-L1 were associated with mortality in ARDS1, ARDS2, and ARDS3. In contrast, higher levels of sPD-L1 in the lung were either not associated with mortality (ARDS2) or were associated with survival (ARDS1). Alveolar PD-1POS T cells had more intracellular cytokine staining compared with PD-1NEG T cells. Subjects without ARDS had a higher ratio of PD-L1POS alveolar macrophages to PD-1POS T cells compared with subjects with ARDS. We conclude that sPD-L1 may have divergent cellular sources and/or functions in the alveolar vs. blood compartments given distinct associations with mortality. Alveolar leukocyte subsets defined by PD-L1/PD-1 cell-surface expression have distinct cytokine secretion profiles, and the relative proportions of these subsets are associated with ARDS.

Transcriptional phenocopies of deleterious KEAP1 mutations correlate with survival outcomes in lung cancer treated with immunotherapy.

PURPOSE: Co-occurring mutations in KEAP1 and STK11KRAS have emerged as determinants of survival outcomes in non-small cell lung cancer (NSCLC) patients treated with immunotherapy. However, these mutational contexts identify a fraction of non-responders to immune checkpoint inhibitors. We hypothesized that KEAP1 wild-type tumors recapitulate the transcriptional footprint of KEAP1 mutations, and that this KEAPness phenotype can determine immune responsiveness with higher precision compared to mutation-based models. EXPERIMENTAL DESIGN: The TCGA was used to infer the KEAPness phenotype and explore its immunological correlates at the pan-cancer level. The association between KEAPness and survival outcomes was tested in two independent cohorts of advanced NSCLC patients treated with immunotherapy and profiled by RNA-Seq (SU2C n=153; OAK/POPLAR n=439). The NSCLC TRACERx421 multi-region sequencing study (tumor regions n=947) was used to investigate evolutionary trajectories. RESULTS: KEAPness-dominant tumors represented 50% of all NSCLCs and were associated with shorter progression-free survival (PFS) and overall survival (OS) compared to KEAPness-free cases in independent cohorts of NSCLC patients treated with immunotherapy (SU2C PFS P=0.042, OS P=0.008; OAK/POPLAR PFS P=0.0014, OS P<0.001). Patients with KEAPness tumors had survival outcomes comparable to those with KEAP1-mutant tumors. In the TRACERx421, KEAPness exhibited limited transcriptional intratumoral heterogeneity and immune exclusion, resembling the KEAP1-mutant disease. This phenotypic state occurred across genetically divergent tumors, exhibiting shared and private cancer genes under positive selection when compared to KEAP1-mutant tumors. CONCLUSIONS: We identified a KEAPness phenotype across evolutionary divergent tumors. KEAPness outperforms mutation-based classifiers as a biomarker of inferior survival outcomes in NSCLC patients treated with immunotherapy.

Mechanisms of action behind the protective effects of proactive esophageal cooling during radiofrequency catheter ablation in the left atrium.

Proactive esophageal cooling for the purpose of reducing the likelihood of ablation-related esophageal injury resulting from radiofrequency (RF) cardiac ablation procedures is increasingly being used and has been Food and Drug Administration cleared as a protective strategy during left atrial RF ablation for the treatment of atrial fibrillation. In this review, we examine the evidence supporting the use of proactive esophageal cooling and the potential mechanisms of action that reduce the likelihood of atrioesophageal fistula (AEF) formation. Although the pathophysiology behind AEF formation after thermal injury from RF ablation is not well studied, a robust literature on fistula formation in other conditions (eg, Crohn disease, cancer, and trauma) exists and the relationship to AEF formation is investigated in this review. Likewise, we examine the abundant data in the surgical literature on burn and thermal injury progression as well as the acute and chronic mitigating effects of cooling. We discuss the relationship of these data and maladaptive healing mechanisms to the well-recognized postablation pathophysiological effects after RF ablation. Finally, we review additional important considerations such as patient selection, clinical workflow, and implementation strategies for proactive esophageal cooling.

Specific CD4+ T cell phenotypes associate with bacterial control in people who 'resist' infection with Mycobacterium tuberculosis.

A subset of individuals exposed to Mycobacterium tuberculosis (Mtb) that we refer to as 'resisters' (RSTR) show evidence of IFN-γ- T cell responses to Mtb-specific antigens despite serially negative results on clinical testing. Here we found that Mtb-specific T cells in RSTR were clonally expanded, confirming the priming of adaptive immune responses following Mtb exposure. RSTR CD4+ T cells showed enrichment of TH17 and regulatory T cell-like functional programs compared to Mtb-specific T cells from individuals with latent Mtb infection. Using public datasets, we showed that these TH17 cell-like functional programs were associated with lack of progression to active tuberculosis among South African adolescents with latent Mtb infection and with bacterial control in nonhuman primates. Our findings suggested that RSTR may successfully control Mtb following exposure and immune priming and established a set of T cell biomarkers to facilitate further study of this clinical phenotype.

The Risk of Medication-Related Osteonecrosis of the Jaw in Children: Guidance for Antiresorptive Use in Pediatric Patients.

BACKGROUND: Antiresorptive targeted cancer therapies, such as denosumab and bisphosphonates, are used in adults, but their application in pediatric cancer is more recent. Side effects such as osteonecrosis of the jaw (ONJ) observed in adults have curtailed use of these medications in the pediatric population. PURPOSE: This study assesses the frequency of ONJ, other side effects, and the indications for use of denosumab versus bisphosphonates in pediatric subjects. STUDY DESIGN, SETTING, SAMPLE: A retrospective cohort study of pediatric subjects who underwent bisphosphonate or denosumab therapy at our institution from 2007-2023 was conducted. Subjects aged ≥ 18 years at therapy initiation were excluded. INDEPENDENT VARIABLE: The independent variable was antiresorptive therapy divided into 2 groups, treatment with intravenous bisphosphonates or denosumab. MAIN OUTCOME VARIABLE(S): Primary outcomes were development of bisphosphonate-related and denosumab-related ONJ. Secondary outcomes included additional side effects. COVARIATES: ONJ risk factors, subject demographics, indications for use, timing, duration, and cumulative dose of antiresorptive therapy were abstracted. ANALYSES: Univariate and bivariate statistics were computed to describe the sample and measure associations between antiresorptive therapy and outcomes. P values < .05 conferred statistical significance. RESULTS: The sample was composed of 178 subjects with a mean age of 11.7 ± 6.1 years. There were 14 (7.9%) and 164 (92.1%) subjects treated with denosumab and bisphosphonate therapies, respectively. There were 0 cases of ONJ across all subjects. The most common indication for treatment was adjuvant targeted therapy for aggressive tumors and malignancy (39.3%) followed by osteoporosis (14.6%). Subjects treated with denosumab had higher frequencies of hypercalcemia and severe bone pain than subjects treated with bisphosphonates, 28.6% versus 1.2% (P < .001) and 14.3% versus 0.00% (P < .001), respectively. CONCLUSION AND RELEVANCE: While invasive dental procedures are ideally performed before antiresorptive treatment, our data suggest that bisphosphonates may be used safely in the pediatric population with low concern for ONJ. Our data also demonstrated bisphosphonates may have a more tolerable side effect profile than denosumab. If the perceived benefits are similar, we recommend using bisphosphonates as first-line therapy in children while reserving denosumab for refractory cases. Future studies will help determine long-term side effects and differences in efficacies of these medications.

Post-acute and Chronic Kidney Function Outcomes of COVID-19 in Children and Adolescents: An EHR Cohort Study from the RECOVER Initiative.

We investigated the risks of post-acute and chronic adverse kidney outcomes of SARS-CoV-2 infection in the pediatric population via a retrospective cohort study using data from the RECOVER program. We included 1,864,637 children and adolescents under 21 from 19 children's hospitals and health institutions in the US with at least six months of follow-up time between March 2020 and May 2023. We divided the patients into three strata: patients with pre-existing chronic kidney disease (CKD), patients with acute kidney injury (AKI) during the acute phase (within 28 days) of SARS-CoV-2 infection, and patients without pre-existing CKD or AKI. We defined a set of adverse kidney outcomes for each stratum and examined the outcomes within the post-acute and chronic phases after SARS-CoV-2 infection. In each stratum, compared with the non-infected group, patients with COVID-19 had a higher risk of adverse kidney outcomes. For patients without pre-existing CKD, there were increased risks of CKD stage 2+ (HR 1.20; 95% CI: 1.13-1.28) and CKD stage 3+ (HR 1.35; 95% CI: 1.15-1.59) during the post-acute phase (28 days to 365 days) after SARS-CoV-2 infection. Within the post-acute phase of SARS-CoV-2 infection, children and adolescents with pre-existing CKD and those who experienced AKI were at increased risk of progression to a composite outcome defined by at least 50% decline in estimated glomerular filtration rate (eGFR), eGFR <15 mL/min/1.73m2, End Stage Kidney Disease diagnosis, dialysis, or transplant.

Traumatic Brain Injury as an Independent Predictor of Futility in the Early Resuscitation of Patients in Hemorrhagic Shock.

This review explores the concept of futility timeouts and the use of traumatic brain injury (TBI) as an independent predictor of the futility of resuscitation efforts in severely bleeding trauma patients. The national blood supply shortage has been exacerbated by the lingering influence of the COVID-19 pandemic on the number of blood donors available, as well as by the adoption of balanced hemostatic resuscitation protocols (such as the increasing use of 1:1:1 packed red blood cells, plasma, and platelets) with and without early whole blood resuscitation. This has underscored the urgent need for reliable predictors of futile resuscitation (FR). As a result, clinical, radiologic, and laboratory bedside markers have emerged which can accurately predict FR in patients with severe trauma-induced hemorrhage, such as the Suspension of Transfusion and Other Procedures (STOP) criteria. However, the STOP criteria do not include markers for TBI severity or transfusion cut points despite these patients requiring large quantities of blood components in the STOP criteria validation cohort. Yet, guidelines for neuroprognosticating patients with TBI can require up to 72 h, which makes them less useful in the minutes and hours following initial presentation. We examine the impact of TBI on bleeding trauma patients, with a focus on those with coagulopathies associated with TBI. This review categorizes TBI into isolated TBI (iTBI), hemorrhagic isolated TBI (hiTBI), and polytraumatic TBI (ptTBI). Through an analysis of bedside parameters (such as the proposed STOP criteria), coagulation assays, markers for TBI severity, and transfusion cut points as markers of futilty, we suggest amendments to current guidelines and the development of more precise algorithms that incorporate prognostic indicators of severe TBI as an independent parameter for the early prediction of FR so as to optimize blood product allocation.

Minimally Invasive Surgery for Colorectal Cancer: Benchmarking Uptake for a Regional Improvement Programme.

BACKGROUND: The uptake of minimally invasive surgery (MIS) for patients with colorectal cancer has progressed at differing rates, both across countries, and within countries. This study aimed to investigate uptake for a regional colorectal cancer improvement programme in England. METHOD: We calculated the proportion of patients receiving elective laparoscopic and robot-assisted surgery amongst those diagnosed with colorectal cancer over 3 time periods (2007-2011, 2012-2016 and 2017-2021) in hospitals participating in the Yorkshire Cancer Research Bowel Cancer Improvement Programme (YCR BCIP). These were benchmarked against national rates. Regression analysis and funnel plots were used to develop a data driven approach for analysing trends in the use of MIS at hospitals in the programme. RESULTS: In England, resections performed by MIS increased from 34.9% to 72.9% for colon cancer and from 28.8% to 72.5% for rectal cancer. Robot-assisted surgery increased from 0.1% to 2.7% for colon cancer and from 0.2% to 7.9% for rectal cancer. Wide variation in the uptake of MIS was observed at a hospital level. Detailed analysis of the YCR BCIP region identified a decreasing number of surgical departments, since the start of the programme, as potential outliers for MIS when compared to the English national average. CONCLUSION: Wide variation in use of MIS for colorectal cancer exists within the English National Health Service and a data-driven approach can help identify outlying hospitals. Addressing some of the challenges behind the uptake of MIS, such as ensuring adequate provision of surgical training and equipment, could help increase its use.

A feasibility study to assess the recruitment and retention of pregnant patients who regularly use cannabis.

OBJECTIVE: To assess first-trimester recruitment and retention of pregnant patients who regularly used cannabis, but not other substances, measured by willingness to participate in a research study, completion of self-administered electronic questionnaires, and willingness to provide urine samples during each trimester of pregnancy. We designed and launched a prospective feasibility study titled, Cannabis Legalization in Michigan (CALM) - Maternal & Infant Health (MIH), in two Michigan clinics after the recreational use of cannabis became legal for adults 21 years and older. RESULTS: Over half (52%) of patients asked to participate in CALM-MIH were consented to the study. Two-thirds (66%) of screened patients initiated prenatal care during their first trimester of pregnancy and 50% used cannabis, of which the majority did not concurrently use other substances. Of those recruited into the prospective study, all participants completed the first-trimester questionnaire and provided urine samples. Study retention was 80% and all participants who completed follow-up assessments were willing to provide urine samples.

A Nationwide Analysis of the Impact of Cardiopulmonary Anomalies on Cleft Palate Surgical Outcomes.

OBJECTIVE: To increase awareness and improve perioperative care of patients with cleft palate (CP) and coexisting cardiopulmonary anomalies. DESIGN: Retrospective cohort. SETTING: Multi-center. PATIENTS/PARTICIPANTS: Patients who underwent surgical repair of CP between 2012-2020 identified in the American College of Surgeons National Surgical Quality Improvement Program Pediatric Data File. Chi-squared analysis and Student's t-test were implemented to make associations between congenital heart disease (CHD) and congenital pulmonary disease (CPD) and postoperative complications. Multiple logistic regression was performed to identify associations between CP and CHD/CPD while controlling for age, gender, and ASA class. C2 values were used to assess the logistic regressions, with a significance level of 0.05 indicating statistical significance. MAIN OUTCOMES MEASURES: Length of stay (LOS), perioperative complications (readmission, reoperation, reintubation, wound dehiscence, cerebrovascular accidents, and mortality). RESULTS: 9 96 181 patients were identified in the database, 17 786 of whom were determined to have CP, of whom 16.0% had congenital heart defects (CHD) and 13.2% had congenital pulmonary defects (CPD). Patients with CHD and CPD were at a significantly greater risk of increased LOS and all but one operative complication rate (wound dehiscence) relative to patients with CP without a history of CHD and CPD. CONCLUSION: This study suggests that congenital cardiopulmonary disease is associated with increased adverse outcomes in the setting of CP repair. Thus, heightened clinical suspicion for coexisting congenital anomalies in the presence of CP should prompt referring providers to perform a comprehensive and multidisciplinary evaluation to ensure cardiopulmonary optimization prior to surgical intervention.

Inpatient versus Outpatient Alveolar Bone Grafting: A Nationwide Cost Analysis.

OBJECTIVE: To compare postoperative outcomes and costs between inpatient and outpatient ABG in the United States. DESIGN: Retrospective cohort. SETTING: Multi-institutional/national. PATIENTS AND PARTICIPANTS: Patients who underwent ABG (n = 6649) were identified in the National Surgical Quality Improvement Program Pediatric database from 2012-2021. Inpatient and outpatient cohorts were matched using coarsened exact matching. MAIN OUTCOMES MEASURE(S): Thirty-day readmission, reoperation, and complications. A modified Markov model was developed to estimate the cost difference between cohorts. One-way and probabilistic sensitivity analyses were performed. RESULTS: After matching, 3718 patients were included, of which 1859 patients were in each hospital-setting cohort. The inpatient cohort had significantly higher rates of reoperations (0.6% vs. 0.2%; p = 0.032) and surgical site infections (0.8% vs. 0.2%; p = 0.018). The total cost of outpatient ABG was estimated to be $10,824 vs. $20,955 for inpatient ABG, resulting in $10,131 cost savings per patient. Probabilistic sensitivity analysis revealed that all 10,000 simulations resulted in consistent cost savings for the outpatient cohort that ranged from $8000 to $24,000. CONCLUSIONS: Outpatient ABG has become increasingly more popular over the past ten years, with a majority of cases being performed in the ambulatory setting. If deemed safe for the individual patient, outpatient ABG may confer a lower risk of nosocomial complications and offer significant cost savings to the healthcare economy.

Close Proximity to Mining Is Associated with Increased Prevalence of the Drug Resistance-Associated Mutation dhps540E in Eastern Democratic Republic of the Congo.

Increasing sulfadoxine-pyrimethamine (SP) resistance in the Democratic Republic of the Congo (DRC) has threatened its use for prevention of malaria in one of the most malarious countries in the world. Using geographic information on mining operations in the DRC and genetic data on SP drug resistance markers from the 2013-2014 Demographic and Health Surveys, we evaluated associations between close residence to mining and the presence of mutations conferring resistance to sulfadoxine. Close residential proximity to mining was associated with increased prevalence odds ratio (POR) of the dhps540E mutation (POR: 2.11, 95% uncertainty interval: 1.15-3.96) with adjustments for confounding variables and space. Our findings indicate that exposure to mining is associated with increased presence of an antimalarial drug resistance haplotype that threatens effective use of SP for vulnerable populations. Areas actively engaged in mining could be considered for interventions to reduce the spread of emerging drug resistance in the DRC.

Full decongestion in acute heart failure therapy.

Incomplete decongestion is the main cause of readmission in the early post-discharge period of a hospitalization for acute heart failure. Recent heart failure guidelines have highlighted initiation and rapid up-titration of quadruple therapy with angiotensin receptor neprilysin inhibitor, beta adrenergic receptor blocker, mineralocorticoid receptor antagonist, and sodium glucose cotransporter 2 inhibitor to prevent hospitalizations for heart failure with reduced ejection fraction. However, full decongestion remains the foremost therapeutic goal of hospitalization for heart failure. While early addition of sodium glucose cotransporter 2 inhibitors and mineralocorticoid receptor antagonists may be helpful, the value of the other therapeutics comes after decongestion is complete.

Cost-effectiveness of interventions for HIV/AIDS, malaria, syphilis, and tuberculosis in 128 countries: a meta-regression analysis.

BACKGROUND: Cost-effectiveness analyses have been conducted for many interventions for HIV/AIDS, malaria, syphilis, and tuberculosis, but they have not been conducted for all interventions that are currently recommended in all countries. To support national decision makers in the effective allocation of resources, we conducted a meta-regression analysis of published incremental cost-effectiveness ratios (ICERs) for interventions for these causes, and predicted ICERs for 14 recommended interventions for Global Fund-eligible countries. METHODS: In the meta-regression analysis, we used data from the Tufts University Center for the Evaluation of Value and Risk in Health (Boston, MA, USA) Cost-Effectiveness Registries (the CEA Registry beginning in 1976 and the Global Health CEA registry beginning in 1995) up to Jan 1, 2018. To create analysis files, we standardised and mapped the data, extracted additional data from published articles, and added variables from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Then we selected ratios for interventions with a minimum of two published articles and three published ICERs that mapped to one of five GBD causes (HIV/AIDS, malaria, syphilis, drug-susceptible tuberculosis, or multi-drug resistant tuberculosis), and to a GBD country; reported a currency year during or after 1990; and for which the comparator intervention was defined as no intervention, standard of care, or placebo. Our meta-regression analysis used all available data on 25 eligible interventions, and quantified the association between ICERs and factors at country level and intervention level. We used a five-stage statistical model that was developed to synthesise evidence on cost-effectiveness analyses, and we adapted it for smaller sample sizes by grouping interventions by cause and type (ie, prevention, diagnostics, and treatment). Using the meta-regression parameters we predicted country-specific median ICERs, IQRs, and 95% uncertainty intervals in 2019 US$ per disability-adjusted life-year (DALY) for 14 currently recommended interventions. We report ICERs in league tables with gross domestic product (GDP) per capita and country-specific thresholds. FINDINGS: The sample for the analysis was 1273 ratios from 144 articles, of which we included 612 ICERs from 106 articles in our meta-regression analysis. We predicted ICERs for antiretroviral therapy for prevention for two age groups and pregnant women, pre-exposure prophylaxis against HIV for two risk groups, four malaria prevention interventions, antenatal syphilis screening, two tuberculosis prevention interventions, the Xpert tuberculosis test, and chemotherapy for drug-sensitive tuberculosis. At the country level, ranking of interventions and number of interventions with a predicted median ICER below the country-specific threshold varied greatly. For instance, median ICERs for six of 14 interventions were below the country-specific threshold in Sudan, whereas 12 of 14 were below the country-specific threshold in Peru. Antenatal syphilis screening had the lowest median ICER among all 14 interventions in 81 (63%) of 128 countries, ranging from $3 (IQR 2-4) per DALY averted in Equatorial Guinea to $3473 (2244-5222) in Ukraine. Pre-exposure prophylaxis for HIV/AIDS for men who have sex with men had the highest median ICER among all interventions in 116 (91%) countries, ranging from $2326 (1077-4567) per DALY averted in Lesotho to $53 559 (23 841-108 534) in Maldives. INTERPRETATION: Country-specific league tables highlight the interventions that offer better value per DALY averted, and can support decision making at a country level that is more tailored to available resources than GDP per capita and country-specific thresholds. Meta-regression is a promising method to synthesise cost-effectiveness analysis results and transfer them across settings. FUNDING: Bill & Melinda Gates Foundation.

L-valine is a powerful stimulator of GLP-1 secretion in rodents and stimulates secretion through ATP-sensitive potassium channels and voltage-gated calcium channels.

BACKGROUND: We previously reported that, among all the naturally occurring amino acids, L-valine is the most powerful luminal stimulator of glucagon-like peptide 1 (GLP-1) release from the upper part of the rat small intestine. This makes L-valine an interesting target for nutritional-based modulation of GLP-1 secretion. However, the molecular mechanism of L-valine-induced secretion remains unknown. METHODS: We aimed to investigate the effect of orally given L-valine in mice and to identify the molecular details of L-valine stimulated GLP-1 release using the isolated perfused rat small intestine and GLUTag cells. In addition, the effect of L-valine on hormone secretion from the distal intestine was investigated using a perfused rat colon. RESULTS: Orally given L-valine (1 g/kg) increased plasma levels of active GLP-1 comparably to orally given glucose (2 g/kg) in male mice, supporting that L-valine is a powerful stimulator of GLP-1 release in vivo (P > 0.05). Luminal L-valine (50 mM) strongly stimulated GLP-1 release from the perfused rat small intestine (P < 0.0001), and inhibition of voltage-gated Ca2+-channels with nifedipine (10 µM) inhibited the GLP-1 response (P < 0.01). Depletion of luminal Na+ did not affect L-valine-induced GLP-1 secretion (P > 0.05), suggesting that co-transport of L-valine and Na+ is not important for the depolarization necessary to activate the voltage-gated Ca2+-channels. Administration of the KATP-channel opener diazoxide (250 µM) completely blocked the L-valine induced GLP-1 response (P < 0.05), suggesting that L-valine induced depolarization arises from metabolism and opening of KATP-channels. Similar to the perfused rat small intestine, L-valine tended to stimulate peptide tyrosine-tyrosine (PYY) and GLP-1 release from the perfused rat colon. CONCLUSIONS: L-valine is a powerful stimulator of GLP-1 release in rodents. We propose that intracellular metabolism of L-valine leading to closure of KATP-channels and opening of voltage-gated Ca2+-channels are involved in L-valine induced GLP-1 secretion.

Mechanistic patterns and clinical implications of oncogenic tyrosine kinase fusions in human cancers.

Tyrosine kinase (TK) fusions are frequently found in cancers, either as initiating events or as a mechanism of resistance to targeted therapy. Partner genes and exons in most TK fusions are followed typical recurrent patterns, but the underlying mechanisms and clinical implications of these patterns are poorly understood. By developing Functionally Active Chromosomal Translocation Sequencing (FACTS), we discover that typical TK fusions involving ALK, ROS1, RET and NTRK1 are selected from pools of chromosomal rearrangements by two major determinants: active transcription of the fusion partner genes and protein stability. In contrast, atypical TK fusions that are rarely seen in patients showed reduced protein stability, decreased downstream oncogenic signaling, and were less responsive to inhibition. Consistently, patients with atypical TK fusions were associated with a reduced response to TKI therapies. Our findings highlight the principles of oncogenic TK fusion formation and selection in cancers, with clinical implications for guiding targeted therapy.

Enhanced Plasmid-Based Transcriptional Activation in Developing Mouse Photoreceptors.

Rod photoreceptor formation in the postnatal mouse is a widely used model system for studying mammalian photoreceptor development. This experimental paradigm provides opportunities for both gain and loss-of-function studies which can be accomplished through in vivo plasmid delivery and electroporation. However, the cis-regulatory elements used to implement this approach have not been fully evaluated or optimized for the unique transcriptional environment of photoreceptors. Here we report that the use of a photoreceptor cis-regulatory element from the Crx gene in combination with broadly active promoter elements can increase the targeting of developing rod photoreceptors in the mouse. This can lead to greater reporter expression, as well as enhanced misexpression and loss-of-function phenotypes in these cells. This study also highlights the importance of identifying and testing relevant cis-regulatory elements when planning cell subtype specific experiments. The use of the specific hybrid elements in this study will provide a more efficacious gene delivery system to study mammalian photoreceptor formation.