Management and outcomes in secondary diabetes among pediatric patients hospitalized with hemophagocytic lymphohistiocytosis.

OBJECTIVES: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder marked by massive cytokine release from macrophage and T-cell activation. Hallmarks include fever, splenomegaly, cytopenias, hypertriglyceridemia, hypofibrinogemia, and elevations in ferritin and soluble IL-2 receptor. Given the association of HLH with inflammation and glucocorticoid therapy, the development of hyperglycemia is not unexpected. Descriptions of the prevalence of secondary diabetes in youth diagnosed with HLH are lacking. METHODS: Retrospective review from 2010 through 2019 of hospitalized youth 0-21 years diagnosed with HLH. The primary outcome of interest was the development of secondary diabetes, defined as a serum glucose 200 mg/dL or higher necessitating insulin therapy. RESULTS: Of 28 patients with HLH, 36 % (n=10) developed secondary diabetes. The only risk factor associated with secondary diabetes was an infectious cause of HLH (60 % vs. 27.8 %, p 0.041). Intravenous regular insulin was used in 80 % of patients with a mean duration of 9.5 days (2-24 days). Most (70 %) needed insulin within 5 days of starting steroids. Stays in the ICU were longer (median 20 vs. 3 days, p 0.007) and intubation more likely (90 vs. 45 %, p 0.041) among those with secondary diabetes. Mortality was high (16-30 %) regardless of insulin use (p 0.634). CONCLUSIONS: One-third of hospitalized pediatric patients with HLH developed secondary diabetes requiring insulin therapy. Insulin is typically started within 5 days of initiating steroids, limited to IV infusions, and often is not needed by discharge. Secondary diabetes was associated with longer ICU stays and heightened risk of intubation.

The proliferation of human mucosal-associated invariant T cells requires a MYC-SLC7A5-glycolysis metabolic axis.

Mucosal-associated invariant T (MAIT) cells are an abundant population of innate T cells that recognize bacterial ligands and play a key role in host protection against bacterial and viral pathogens. Upon activation, MAIT cells undergo proliferative expansion and increase their production of effector molecules such as cytokines. In this study, we found that both mRNA and protein abundance of the key metabolism regulator and transcription factor MYC was increased in stimulated MAIT cells. Using quantitative mass spectrometry, we identified the activation of two MYC-controlled metabolic pathways, amino acid transport and glycolysis, both of which were necessary for MAIT cell proliferation. Last, we showed that MAIT cells isolated from people with obesity showed decreased MYC mRNA abundance upon activation, which was associated with defective MAIT cell proliferation and functional responses. Collectively, our data uncover the importance of MYC-regulated metabolism for MAIT cell proliferation and provide additional insight into the molecular basis for the functional defects of MAIT cells in obesity.

Fecal Microbiota Transfer for Clostridium difficile Infection and Its Effects on Recurrent Urinary Tract Infection.

IMPORTANCE: Recurrent urinary tract infection (rUTI) poses a significant management challenge, and fecal microbiota transfer (FMT) has been shown in a limited manner to positively effect rUTI. OBJECTIVES: The objective of this study was to compare UTI rates after FMT for Clostridium difficile infection (CDI) in patients with previously diagnosed rUTI and patients without a previous diagnosis of rUTI. STUDY DESIGN: This was a retrospective cohort study of female patients who underwent FMT between 2015 and 2020 and were identified from a database at a tertiary care referral center. The electronic medical record was queried for demographic and UTI characteristics in the 3 years before and 5 years after FMT, which were compared between patients with or without a preexisting history of rUTI. RESULTS: One hundred thirty-five patients were included, 17 of whom had a preexisting history of rUTI. The median number of culture-proven UTIs was 1 in the rUTI group versus 0 in the non-rUTI group both in the 1 year ( P = 0.003) and 3 years ( P < 0.001) before FMT. Most UTIs before and after FMT were Escherichia coli UTIs (53.8%) and carried some antibiotic resistance (54.6%). Comparatively, in the year after FMT, there were no differences between groups in UTI frequency or antibiotic administration (0 [0-1] vs 0.5 [0-1], P = 0.28). A trend toward decreased frequency of UTI in the 1 year after FMT was seen in the rUTI group. On survival analysis, there was a nonsignificant decrease in the 3-year UTI-free rate for the rUTI group compared with the non-rUTI group (76.5% vs 90.1%, P = 0.07). CONCLUSIONS: Patients with recurrent UTI undergoing FMT for recurrent CDI experienced a trend toward a decrease in frequency of UTI after FMT.

Nonhome Discharge in Patients Undergoing Pelvic Reconstructive Surgery: A National Analysis.

IMPORTANCE: Discharge to home after surgery has been recognized as a determinant of long-term survival and is a common concern in the elderly population. OBJECTIVE: The aim of the study was to determine the incidence and risk factors for nonhome discharge in patients undergoing major surgery for pelvic organ prolapse. STUDY DESIGN: We performed a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program Database from 2010 to 2018. We included patients who underwent sacrocolpopexy, vaginal colpopexy, and colpocleisis. We compared perioperative characteristics in patients who were discharged home versus those who were discharged to a nonhome location. Stepwise backward multivariate logistic regression was then used to control for confounding variables and identify independent predictors of nonhome discharge. RESULTS: A total of 38,012 patients were included in this study, 209 of whom experienced nonhome discharge (0.5%). Independent predictors of nonhome discharge included preoperative weight loss (adjusted odds ratio [aOR], 5.9; 95% confidence interval [CI], 1.3-27.5), dependent health care status (aOR, 5.0; 95% CI, 2.6-9.5), abdominal hysterectomy (aOR, 2.3; 95% CI, 1.4-3.7), American Society of Anesthesiologists class 3 or greater (aOR, 2.0; 95% CI, 1.5-2.7), age (aOR, 1.1; 95% CI, 1.05-1.09), operative time (aOR, 1.005; 95% CI, 1.003-1.006), laparoscopic hysterectomy (aOR, 0.6; 95% CI, 0.4-1.0), and laparoscopic sacrocolpopexy (aOR, 0.5; 95% CI, 0.3-0.8). CONCLUSIONS: In patients undergoing surgery for pelvic organ prolapse, nonhome discharge is associated with various indicators of frailty, including age, health care dependence, and certain comorbidities. An open surgical approach increases the risk of nonhome discharge, while a laparoscopic approach is associated with lower risk.

Association between CT-based body composition assessment and patient outcomes during neoadjuvant chemotherapy for epithelial ovarian cancer.

OBJECTIVE: The aim of this study was to characterize the body composition of patients undergoing neoadjuvant chemotherapy (NACT) for epithelial ovarian cancer (EOC), identify factors associated with sarcopenia at diagnosis, and evaluate the impact of pretreatment sarcopenia and changes in body composition parameters during therapy on perioperative and disease-related outcomes. METHODS: Patients undergoing NACT for EOC between 2008 and 2020 were identified. Pre-treatment and post-treatment contrast-enhanced CT scans were reviewed to determine skeletal muscle index (SMI) and visceral adipose tissue (VAT) area at the mid-fourth lumbar vertebral level. SMI and VAT were analyzed for association with clinical and treatment variables. RESULTS: 174 patients were identified. Mean pretreatment SMI and VAT were 38.3 cm2/m2 ± 7.9 and 51.2 cm2/m2 ± 34.3, respectively. Comparatively, mean post-treatment SMI and VAT were 37.8 cm2/m2 ± 7.9 and 43.7 cm2/m2 ± 29.7, respectively. Most patients exhibited an overall decrease in SMI from pretreatment to posttreatment scans. Caucasian race, older age, and lower body mass index at diagnosis were associated with lower pretreatment SMI. Lower pre-treatment SMI was associated with lower surgical complexity scores (p < 0.001) and estimated blood loss (p = 0.029). Decrease in SMI after NACT was associated with increased rates of ICU admissions and length of stay. While there was no association between SMI and overall survival (OS) or progression-free survival (PFS), >2% decrease per 100 days in VAT was significantly associated with worse OS. CONCLUSIONS: Patients with lower pretreatment SMI tend to undergo less complex surgery than those with higher SMI despite NACT. Decrease in VAT may be a potential indicator of worse OS. Information on body composition can aid in clinical decision making in patients with EOC.

Data standards in pediatric oncology: Past, present, and future.

In this commentary, we highlight the central role that data standards play in facilitating data-driven efforts to advance research in pediatric oncology. We discuss the current state of data standards for pediatric oncology and propose five steps to achieve an improved future state with benefits for clinicians, researchers, and patients.

Ambulatory atrioventricular synchronous pacing over time using a leadless ventricular pacemaker: Primary results from the AccelAV study.

BACKGROUND: Previous studies demonstrated that accelerometer-based, mechanically timed atrioventricular synchrony (AVS) is feasible using a leadless ventricular pacemaker. OBJECTIVE: The purpose of this study was to determine the performance of a leadless ventricular pacemaker with accelerometer-based algorithms that provide AVS pacing. METHODS: AccelAV was a prospective, single-arm study to characterize AVS in patients implanted with a Micra AV, which uses the device accelerometer to mechanically detect atrial contractions and promote VDD pacing. The primary objective was to characterize resting AVS at 1 month in patients with complete atrioventricular block (AVB) and normal sinus function. RESULTS: A total of 152 patients (age 77 ± 11 years; 48% female) from 20 centers were enrolled and implanted with a leadless pacemaker. Among patients with normal sinus function and complete AVB (n = 54), mean resting AVS was 85.4% at 1 month, and ambulatory AVS was 74.8%. In the subset of patients (n = 20) with programming optimization, mean ambulatory AVS was 82.6%, representing a 10.5% improvement (P <.001). Quality of life as measured by the EQ-5D-3L (EuroQol Five-Dimensions Three-Level questionnaire) improved significantly from preimplant to 3 months (P = .031). In 37 patients with AVB at both 1 and 3 months, mean AVS during rest did not differ (86.1% vs 84.1%; P = .43). There were no upgrades to dual-chamber devices or cardiac resynchronization therapy through 3 months. CONCLUSION: Accelerometer-based mechanical atrial sensing provided by a leadless pacemaker implanted in the right ventricle significantly improves quality of life in a select cohort of patients with AV block and normal sinus function. AVS remained stable through 3 months, and there were no system upgrades to dual-chamber pacemakers.

Assessment of Adverse Events in a Matched Cohort of Women Undergoing Concurrent Midurethral Sling at the Time of Minimally Invasive Benign Gynecologic Surgery.

IMPORTANCE: Procedures for stress urinary incontinence and benign gynecologic surgery are often performed concurrently, and associated complication rates have previously been unexplored. OBJECTIVE: The aim of this study was to compare postoperative complication rates between women undergoing midurethral sling (MUS) placement at the time of benign gynecologic surgery and those undergoing MUS alone. STUDY DESIGN: This was a retrospective matched cohort study of women undergoing MUS with or without concurrent minimally invasive benign gynecologic surgery from January 2010 through December 2020. Eligible women undergoing concurrent surgery were matched to a cohort of women undergoing MUS placement alone. The electronic medical record was queried for demographic and perioperative/postoperative data up to 12 months after surgery. RESULTS: Thirty-eight women met inclusion criteria for the concurrent group, and 152 women were matched accordingly. The overall adverse event rate was 39.5% (95% confidence interval [CI], 0.25-0.55) for the concurrent group and 24.3% (95% CI, 0.18-0.32) for the MUS-only group ( P = 0.05). Adverse events with Clavien-Dindo grade ≤ 2 were higher in the concurrent group (Clavien-Dindo Grade 1: 5% vs 0%, P = 0.04; Clavien-Dindo Grade 2: 16% vs 6%, P = 0.04), as was composite postoperative resource utilization (76% vs 49%, P = 0.003). Mesh exposure ( P = 0.03) and sling lysis/excision rates ( P = 0.02) were higher in the concurrent group. On logistic regression, concurrent surgery cases remained significantly associated with sling mesh erosion (adjusted odds ratio, 12.6; 95% CI, 1.4-116.4). CONCLUSIONS: Midurethral sling placement at the time of minimally invasive benign gynecologic surgery is safe but is associated with a higher incidence of postoperative hospital resource utilization and sling mesh extrusion, and a need for revision.

Study protocol for the St James's Hospital, Tallaght University Hospital, Trinity College Dublin Allied Researchers' (STTAR) Bioresource for COVID-19.

Background: The current coronavirus disease 2019 (COVID-19) pandemic began in Ireland with the first confirmed positive case in March 2020. In the early stages of the pandemic clinicians and researchers in two affiliated Dublin hospitals identified the need for a COVID-19 biobanking initiative to support and enhance research into the disease. Through large scale analysis of clinical, regional, and genetic characteristics of COVID-19 patients, biobanks have helped identify, and so protect, at risk patient groups The STTAR Bioresource has been created to collect and store data and linked biological samples from patients with SARS-CoV-2 infection and healthy and disease controls. Aim: The primary objective of this study is to build a biobank, to understand the clinical characteristics and natural history of COVID-19 infection with the long-term goal of research into improved disease understanding, diagnostic tests and treatments. Methods: This is a prospective dual-site cohort study across two tertiary acute university teaching hospitals. Patients are recruited from inpatient wards or outpatient clinics. Patients with confirmed COVID-19 infection as well as healthy and specific disease control groups are recruited.  Biological samples are collected and a case report form detailing demographic and medical background is entered into the bespoke secure online Dendrite database. Impact: The results of this study will be used to inform national and international strategy on health service provision and disease management related to COVID-19. In common with other biobanks, study end points  evolve over time as new research questions emerge. They currently include patient survival, occurrence of severe complications of the disease or its therapy, occurrence of persistent symptoms following recovery from the acute illness and vaccine responses.

The Use of Near-Infrared Spectroscopy and/or Transcranial Doppler as Non-Invasive Markers of Cerebral Perfusion in Adult Sepsis Patients With Delirium: A Systematic Review.

BACKGROUND: Several studies have previously reported the presence of altered cerebral perfusion during sepsis. However, the role of non-invasive neuromonitoring, and the impact of altered cerebral perfusion, in sepsis patients with delirium remains unclear. METHODS: We performed a systematic review of studies that used near-infrared spectroscopy (NIRS) and/or transcranial Doppler (TCD) to assess adults (≥18 years) with sepsis and delirium. From study inception to July 28, 2020, we searched the following databases: Ovid MedLine, Embase, Cochrane Library, and Web of Science. RESULTS: Of 1546 articles identified, 10 met our inclusion criteria. Although NIRS-derived regional cerebral oxygenation was consistently lower, this difference was only statistically significant in one study. TCD-derived cerebral blood flow velocity was inconsistent across studies. Importantly, both impaired cerebral autoregulation during sepsis and increased cerebrovascular resistance were associated with delirium during sepsis. However, the heterogeneity in NIRS and TCD devices, duration of recording (from 10 seconds to 72 hours), and delirium assessment methods (e.g., electronic medical records, confusion assessment method for the intensive care unit), precluded meta-analysis. CONCLUSION: The available literature demonstrates that cerebral perfusion disturbances may be associated with delirium in sepsis. However, future investigations will require consistent definitions of delirium, delirium assessment training, harmonized NIRS and TCD assessments (e.g., consistent measurement site and length of recording), as well as the quantification of secondary and tertiary variables (i.e., Cox, Mxa, MAPOPT), in order to fully assess the relationship between cerebral perfusion and delirium in patients with sepsis.

Moderate Intensity Endurance and Resistance Exercise Attenuates Cachexia in Tumor-bearing Mice.

BACKGROUND/AIM: Cancer cachexia encompasses several deleterious physiological alterations associated with functional impairments, poor quality of life, and increased mortality. The aim of this study was to examine the effects of chronic moderate intensity exercise training on markers of cachexia. MATERIALS AND METHODS: Balb/c mice were randomly assigned to sedentary (SED) or exercise (EX) groups and EX mice were further randomly assigned to one of three exercise modalities (aerobic, resistance, combined). RESULTS: Cachexia was induced in SED animals inoculated with C26 cells, as evidenced by significant changes in numerous markers. All cachexia-related perturbations were significantly attenuated in EX versus SED animals. Systemic inflammation was significantly decreased in all EX groups, as evident by a normalization of spleen mass and plasma IL-6. CONCLUSION: Multiple moderate intensity exercise modalities can provide significant benefits in cachectic mice, and this may be due, at least in part, to decreased systemic inflammation.

Aligning EHR Data for Pediatric Leukemia With Standard Protocol Therapy.

PURPOSE: Children with acute lymphoblastic leukemia (ALL) are treated according to risk-based protocols defined by the Children's Oncology Group (COG). Alignment between real-world clinical practice and protocol milestones is not widely understood. Aggregate deidentified electronic health record (EHR) data offer a useful resource to evaluate real-world clinical practice. METHODS: A cohort of children with ALL was identified in the Cerner Health Facts deidentified aggregate EHR data. Manual review identified candidate procedural milestones. Automated methods were developed to classify likely standard-risk precursor B-cell ALL patients. Milestone procedures were adjusted relative to initiation of therapy and then aligned to the COG protocols for standard induction therapy. RESULTS: We identified 7,728 patients with pediatric ALL with 188,187 encounters. Records for lumbar punctures (LP) and bone marrow biopsies were frequently present in the data and were appropriate targets to evaluate guideline performance. Alluvial graph analysis of 14 health systems indicated that none of the systems have data from all three COG-recommended lumbar procedures for all patients but alignment demonstrated that most systems test at the recommended times. CONCLUSION: Source-system variation introduces inconsistency and incompleteness into aggregate EHR data. Data visualization was helpful in characterizing and interpreting the data. Health systems with patients meeting the inclusion criteria demonstrated strong alignment with the recommended milestones for LP. Large-scale aggregate EHR data are useful to evaluate alignment of recommended versus actual clinical milestones in support of treating children with ALL. This work can inform other guideline and protocol driven care.

Predictors of atrial mechanical sensing and atrioventricular synchrony with a leadless ventricular pacemaker: Results from the MARVEL 2 Study.

BACKGROUND: The MARVEL (Micra Atrial TRacking Using a Ventricular AccELerometer) 2 study assessed the efficacy of atrioventricular (AV) synchronous pacing with a Micra leadless pacemaker. Average atrioventricular synchrony (AVS) was 89.2%. Previously, low amplitude of the Micra-sensed atrial signal (A4) was observed to be a factor of low AVS. OBJECTIVE: The purpose of this study was to identify predictors of A4 amplitude and high AVS. METHODS: We analyzed 64 patients enrolled in MARVEL 2 who had visible P waves on electrocardiogram for assessing A4 amplitude and 40 patients with third-degree AV block for assessing AVS at rest. High AVS was defined as >90% correct atrial-triggered ventricular pacing. The association between clinical factors and echocardiographic parameters with A4 amplitude was investigated using a multivariable model with lasso variable selection. Variables associated with A4 amplitude together with premature ventricular contraction burden, sinus rate, and sinus rate variability (standard deviation of successive differences of P-P intervals [SDSD]) were assessed for association with AVS. RESULTS: In univariate analysis, low A4 amplitude was inversely related to atrial function assessed by E/A ratio and e'/a' ratio, and was directly related to atrial contraction excursion (ACE) and atrial strain (Ɛa) on echocardiography (all P ≤.05). The multivariable lasso regression model found coronary artery bypass graft history, E/A ratio, ACE, and Ɛa were associated with low A4 amplitude. E/A ratio and SDSD were multivariable predictors of high AVS, with >90% probability if E/A <0.94 and SDSD <5 bpm. CONCLUSION: Clinical parameters and echocardiographic markers of atrial function are associated with A4 signal amplitude. High AVS can be predicted by E/A ratio <0.94 and low sinus rate variability at rest.

A Review of Nonanesthetic Uses of Ketamine.

Ketamine, a nonselective NMDA receptor antagonist, is used widely in medicine as an anesthetic agent. However, ketamine's mechanisms of action lead to widespread physiological effects, some of which are now coming to the forefront of research for the treatment of diverse medical disorders. This paper aims at reviewing recent data on key nonanesthetic uses of ketamine in the current literature. MEDLINE, CINAHL, and Google Scholar databases were queried to find articles related to ketamine in the treatment of depression, pain syndromes including acute pain, chronic pain, and headache, neurologic applications including neuroprotection and seizures, and alcohol and substance use disorders. It can be concluded that ketamine has a potential role in the treatment of all of these conditions. However, research in this area is still in its early stages, and larger studies are required to evaluate ketamine's efficacy for nonanesthetic purposes in the general population.

Atrioventricular Synchronous Pacing Using a Leadless Ventricular Pacemaker: Results From the MARVEL 2 Study.

OBJECTIVES: This study reports on the performance of a leadless ventricular pacemaker with automated, enhanced accelerometer-based algorithms that provide atrioventricular (AV) synchronous pacing. BACKGROUND: Despite many advantages, leadless pacemakers are currently only capable of single-chamber ventricular pacing. METHODS: The prospective MARVEL 2 (Micra Atrial tRacking using a Ventricular accELerometer 2) study assessed the performance of an automated, enhanced accelerometer-based algorithm downloaded to the Micra leadless pacemaker for up to 5 h in patients with AV block. The primary efficacy objective was to demonstrate the superiority of the algorithm to provide AV synchronous (VDD) pacing versus VVI-50 pacing in patients with sinus rhythm and complete AV block. The primary safety objective was to demonstrate that the algorithm did not result in pauses or heart rates of >100 beats/min. RESULTS: Overall, 75 patients from 12 centers were enrolled; an accelerometer-based algorithm was downloaded to their leadless pacemakers. Among the 40 patients with sinus rhythm and complete AV block included in the primary efficacy objective analysis, the proportion of patients with ≥70% AV synchrony at rest was significantly greater with VDD pacing than with VVI pacing (95% vs. 0%; p < 0.001). The mean percentage of AV synchrony increased from 26.8% (median: 26.9%) during VVI pacing to 89.2% (median: 94.3%) during VDD pacing. There were no pauses or episodes of oversensing-induced tachycardia reported during VDD pacing in all 75 patients. CONCLUSIONS: Accelerometer-based atrial sensing with an automated, enhanced algorithm significantly improved AV synchrony in patients with sinus rhythm and AV block who were implanted with a leadless ventricular pacemaker. (Micra Atrial Tracking Using a Ventricular Accelerometer 2 [MARVEL 2]; NCT03752151).

Mucosal-Associated Invariant T Cells Display Diminished Effector Capacity in Oesophageal Adenocarcinoma.

Oesophageal adenocarcinoma (OAC) is an aggressive malignancy with poor prognosis, and incidence is increasing rapidly in the Western world. Mucosal-associated invariant T (MAIT) cells recognize bacterial metabolites and kill infected cells, yet their role in OAC is unknown. We aimed to elucidate the role of MAIT cells during cancer development by characterizing the frequency, phenotype, and function of MAIT cells in human blood and tissues, from OAC and its pre-malignant inflammatory condition Barrett's oesophagus (BO). Blood and tissues were phenotyped by flow cytometry and conditioned media from explanted tissue was used to model the effects of the tumor microenvironment on MAIT cell function. Associations were assessed between MAIT cell frequency, circulating inflammatory markers, and clinical parameters to elucidate the role of MAIT cells in inflammation driven cancer. MAIT cells were decreased in BO and OAC blood compared to healthy controls, but were increased in oesophageal tissues, compared to BO-adjacent tissue, and remained detectable after neo-adjuvant treatment. MAIT cells in tumors expressed CD8, PD-1, and NKG2A but lower NKG2D than BO cohorts. MAIT cells produced less IFN-γ and TNF-α in the presence of tumor-conditioned media. OAC cell line viability was reduced upon exposure to expanded MAIT cells. Serum levels of chemokine IP-10 were inversely correlated with MAIT cell frequency in both tumors and blood. MAIT cells were higher in the tumors of node-negative patients, but were not significantly associated with other clinical parameters. This study demonstrates that OAC tumors are infiltrated by MAIT cells, a type of CD8 T cell featuring immune checkpoint expression and cytotoxic potential. These findings may have implications for immunotherapy and immune scoring approaches.

Obesity Reduces mTORC1 Activity in Mucosal-Associated Invariant T Cells, Driving Defective Metabolic and Functional Responses.

Obesity underpins the development of numerous chronic diseases, such as type II diabetes mellitus. It is well established that obesity negatively alters immune cell frequencies and functions. Mucosal-associated invariant T (MAIT) cells are a population of innate T cells, which we have previously reported are dysregulated in obesity, with altered circulating and adipose tissue frequencies and a reduction in their IFN-γ production, which is a critical effector function of MAIT cells in host defense. Hence, there is increased urgency to characterize the key molecular mechanisms that drive MAIT cell effector functions and to identify those which are impaired in the obesity setting. In this study, we found that MAIT cells significantly upregulate their rates of glycolysis upon activation in an mTORC1-dependent manner, and this is essential for MAIT cell IFN-γ production. Furthermore, we show that mTORC1 activation is dependent on amino acid transport via SLC7A5. In obese patients, using RNA sequencing, Seahorse analysis, and a series of in vitro experiments, we demonstrate that MAIT cells isolated from obese adults display defective glycolytic metabolism, mTORC1 signaling, and SLC7A5 aa transport. Collectively, our data detail the intrinsic metabolic pathways controlling MAIT cell cytokine production and highlight mTORC1 as an important metabolic regulator that is impaired in obesity, leading to altered MAIT cell responses.

Sodium salicylate alters temporal integration measured through increasing stimulus presentation rates.

OBJECTIVE: High doses of sodium salicylate (SS) are known to induce tinnitus, general hyperexcitability in the central auditory system, and to cause mild hearing loss. We used the auditory brainstem response (ABR) to assess the effects of SS on auditory sensitivity and temporal processing in the auditory nerve and brainstem. ABRs were evoked using tone burst stimuli varying in frequency and intensity with presentation rates from 11/s to 81/s. DESIGN: ABRs were recorded and analysed prior to and after SS treatment in each animal, and peak 1 and peak 4 amplitudes and latencies were determined along with minimal response threshold. STUDY SAMPLE: Nine young adult CBA/CaJ mice were used in a longitudinal within-subject design. RESULTS: No measurable effects of presentation rate were found on ABR threshold prior to SS; however, following SS administration increasing stimulus rates lowered ABR thresholds by as much as 10 dB and compressed the peak amplitude by intensity level functions. CONCLUSIONS: These results suggest that SS alters temporal integration and compressive nonlinearity, and that varying the stimulus rate of the ABR may prove to be a useful diagnostic tool in the study of hearing disorders that involve hyperexcitability.

Accelerometer-based atrioventricular synchronous pacing with a ventricular leadless pacemaker: Results from the Micra atrioventricular feasibility studies.

BACKGROUND: Micra is a leadless pacemaker that is implanted in the right ventricle and provides rate response via a 3-axis accelerometer (ACC). Custom software was developed to detect atrial contraction using the ACC enabling atrioventricular (AV) synchronous pacing. OBJECTIVE: The purpose of this study was to sense atrial contractions from the Micra ACC signal and provide AV synchronous pacing. METHODS: The Micra Accelerometer Sensor Sub-Study (MASS) and MASS2 early feasibility studies showed intracardiac accelerations related to atrial contraction can be measured via ACC in the Micra leadless pacemaker. The Micra Atrial TRacking Using A Ventricular AccELerometer (MARVEL) study was a prospective multicenter study designed to characterize the closed-loop performance of an AV synchronous algorithm downloaded into previously implanted Micra devices. Atrioventricular synchrony (AVS) was measured during 30 minutes of rest and during VVI pacing. AVS was defined as a P wave visible on surface ECG followed by a ventricular event <300 ms. RESULTS: A total of 64 patients completed the MARVEL study procedure at 12 centers in 9 countries. Patients were implanted with a Micra for a median of 6.0 months (range 0-41.4). High-degree AV block was present in 33 patients, whereas 31 had predominantly intrinsic conduction during the study. Average AVS during AV algorithm pacing was 87.0% (95% confidence interval 81.8%-90.9%), 80.0% in high-degree block patients and 94.4% in patients with intrinsic conduction. AVS was significantly greater (P <.001) during AV algorithm pacing compared to VVI in high-degree block patients, whereas AVS was maintained in patients with intrinsic conduction. CONCLUSION: Accelerometer-based atrial sensing is feasible and significantly improves AVS in patients with AV block and a single-chamber leadless pacemaker implanted in the right ventricle.