Methylation of histone H3 lysine 4 is required for maintenance of beta cell function in adult mice.

AIMS/HYPOTHESIS: Beta cells control glucose homeostasis via regulated production and secretion of insulin. This function arises from a highly specialised gene expression programme that is established during development and then sustained, with limited flexibility, in terminally differentiated cells. Dysregulation of this programme is seen in type 2 diabetes but mechanisms that preserve gene expression or underlie its dysregulation in mature cells are not well resolved. This study investigated whether methylation of histone H3 lysine 4 (H3K4), a marker of gene promoters with unresolved functional importance, is necessary for the maintenance of mature beta cell function. METHODS: Beta cell function, gene expression and chromatin modifications were analysed in conditional Dpy30 knockout mice, in which H3K4 methyltransferase activity is impaired, and in a mouse model of diabetes. RESULTS: H3K4 methylation maintains expression of genes that are important for insulin biosynthesis and glucose responsiveness. Deficient methylation of H3K4 leads to a less active and more repressed epigenome profile that locally correlates with gene expression deficits but does not globally reduce gene expression. Instead, developmentally regulated genes and genes in weakly active or suppressed states particularly rely on H3K4 methylation. We further show that H3K4 trimethylation (H3K4me3) is reorganised in islets from the Leprdb/db mouse model of diabetes in favour of weakly active and disallowed genes at the expense of terminal beta cell markers with broad H3K4me3 peaks. CONCLUSIONS/INTERPRETATION: Sustained methylation of H3K4 is critical for the maintenance of beta cell function. Redistribution of H3K4me3 is linked to gene expression changes that are implicated in diabetes pathology.

Endoscopy Unit Level Interventions to Improve Adenoma Detection Rate: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: Adenoma detection rate (ADR) is inversely correlated with the risk of interval colon cancer and is a key target for quality improvement in endoscopy units. We conducted a systematic review and meta-analysis to identify and evaluate the effectiveness of interventions that can be implemented at the endoscopy unit level to improve ADRs. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search was conducted in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases between January 1990 and December 2022 to identify relevant studies. Both randomized controlled trials and observational studies were eligible. Data for the primary outcome of ADR were analyzed and reported on the log-odds scale with 95% CIs using a random-effects meta-analysis model using the empiric Bayes estimator. RESULTS: From 10,778 initial citations, 34 studies were included in the meta-analysis comprising 371,041 procedures and 1501 endoscopists. The provision of report cards (odds ratio [OR], 1.28; 95% CI, 1.13-1.45; P < .001) and the presence of an additional observer to identify polyps (OR, 1.25; 95% CI, 1.09-1.43; P = .002) were associated with significant increases in ADRs whereas multimodal interventions were borderline significant (OR, 1.18; 95% CI, 1.00-1.40; P = .05) and withdrawal time monitoring was not associated significantly with an increase in ADRs (OR, 1.35; 95% CI, 0.93-1.96; P = .11). CONCLUSIONS: The provision of report cards and the presence of an additional observer to identify polyps are associated with improved ADRs and should be considered for implementation in endoscopy facilities.

Length of Uninterrupted CAG, Independent of Polyglutamine Size, Results in Increased Somatic Instability, Hastening Onset of Huntington Disease.

Huntington disease (HD) is caused by a CAG repeat expansion in the huntingtin (HTT) gene. Although the length of this repeat is inversely correlated with age of onset (AOO), it does not fully explain the variability in AOO. We assessed the sequence downstream of the CAG repeat in HTT [reference: (CAG)n-CAA-CAG], since variants within this region have been previously described, but no study of AOO has been performed. These analyses identified a variant that results in complete loss of interrupting (LOI) adenine nucleotides in this region [(CAG)n-CAG-CAG]. Analysis of multiple HD pedigrees showed that this LOI variant is associated with dramatically earlier AOO (average of 25 years) despite the same polyglutamine length as in individuals with the interrupting penultimate CAA codon. This LOI allele is particularly frequent in persons with reduced penetrance alleles who manifest with HD and increases the likelihood of presenting clinically with HD with a CAG of 36-39 repeats. Further, we show that the LOI variant is associated with increased somatic repeat instability, highlighting this as a significant driver of this effect. These findings indicate that the number of uninterrupted CAG repeats, which is lengthened by the LOI, is the most significant contributor to AOO of HD and is more significant than polyglutamine length, which is not altered in these individuals. In addition, we identified another variant in this region, where the CAA-CAG sequence is duplicated, which was associated with later AOO. Identification of these cis-acting modifiers have potentially important implications for genetic counselling in HD-affected families.

Glutaminase Deficiency Caused by Short Tandem Repeat Expansion in GLS.

We report an inborn error of metabolism caused by an expansion of a GCA-repeat tract in the 5' untranslated region of the gene encoding glutaminase (GLS) that was identified through detailed clinical and biochemical phenotyping, combined with whole-genome sequencing. The expansion was observed in three unrelated patients who presented with an early-onset delay in overall development, progressive ataxia, and elevated levels of glutamine. In addition to ataxia, one patient also showed cerebellar atrophy. The expansion was associated with a relative deficiency of GLS messenger RNA transcribed from the expanded allele, which probably resulted from repeat-mediated chromatin changes upstream of the GLS repeat. Our discovery underscores the importance of careful examination of regions of the genome that are typically excluded from or poorly captured by exome sequencing.

A Multicenter Randomized Controlled Trial Comparing Two Bowel Cleansing Regimens for Colonoscopy After Failed Bowel Preparation.

BACKGROUND & AIMS: Failed bowel preparation for colonoscopy occurs commonly, but the optimal regimen for the subsequent attempt is unknown. High-volume preparations often are used but are not well studied. The objective of this study was to compare the efficacy, tolerability, and safety of 2 regimens for use after failed bowel preparation. METHODS: A multicenter, endoscopist-blinded randomized controlled trial was conducted in patients who previously failed bowel preparation despite adequate compliance. Patients were randomized to 1 of 2 split polyethylene glycol (PEG) regimens, preceded by 15 mg bisacodyl: PEG 2 L the evening before and 2 L the day of colonoscopy (PEG 2+2L+bisacodyl), or 4 L and 2 L (PEG 4+2L+bisacodyl). All patients followed a low-fiber diet on both the third and second day before the procedure, followed by a clear fluid diet the day before and the morning of the colonoscopy. The primary outcome was adequate bowel preparation, defined as a Boston Bowel Preparation Scale total score of 6 or higher, with all segment scores of 2 or higher. Secondary outcomes included adenoma detection rate, advanced adenoma detection rate, sessile serrated lesion detection, cecal intubation rate, tolerability, and adverse events. RESULTS: A total of 196 subjects were randomized at 4 academic centers in Canada (mean age, 60.7 y; SD, 11.4 y; 44.9% were women). There were no significant differences between the PEG 2+2L+bisacodyl and the PEG 4+2L+bisacodyl groups in achieving adequate bowel preparation (91.2% vs 87.6%; P = .44). There were no significant differences with regard to mean adenoma detection rate (37.4% vs 31.5%; P = .41), advanced adenoma detection rate (18.7% vs 11.2%; P = .16), sessile serrated lesion detection (8.8% vs 5.6%; P = .41), and cecal intubation rate (96.7% vs 92.1%; P = .19). The 2 regimens were similarly well tolerated, but PEG 2+2L+bisacodyl was associated with a higher willingness to repeat the bowel preparation (91.2% vs 66.2%; P < .001). CONCLUSIONS: Split-dose 4 L-PEG with 15 mg bisacodyl, along with dietary restrictions, has similar efficacy as a higher-volume preparation, and should be considered for patients who previously failed bowel preparation (ClinicalTrials.gov number, NCT02976805).

Intravenous Ustekinumab Reinduction Is Effective in Prior Biologic Failure Crohn's Disease Patients Already on Every-4-Week Dosing.

Ustekinumab (UST) targets the common subunit (p40) of interleukins-12/23,1,2 approved for intravenous (IV) induction of remission in moderate-to-severe Crohn's disease (CD), followed by subcutaneous (SC) doses for maintenance of remission.3,4 The role of IV reinduction of UST in patients already on every-4-week (Q4) maintenance with partial response or loss of response (LOR) is unclear.5 The aim was to assess response and remission rates for UST IV reinduction in patients with CD with partial response or LOR who already were on Q4 SC dosing and had failed prior biological therapies.

Baseline levels of seminal reactive oxygen species predict improvements in sperm function following antioxidant therapy in men with infertility.

BACKGROUND: Poor sperm function is a major cause of infertility. There is no drug therapy to improve sperm function. Semen oxidative stress is a recently identified pathway for sperm damage. Commercial antioxidants such as L-carnitine and acetyl-L-carnitine (LAL) are commonly self-administered by infertile men. However, concerns have been raised whether inappropriate LAL therapy causes reductive stress-mediated sperm damage. It is imperative to investigate whether: (1) LAL improves sperm function by reducing reactive oxidative species (ROS); (2) LAL has differential effects on sperm function between men with normal and elevated ROS. METHODS: A prospective cohort study of routine clinical practice was performed in infertile men with abnormal sperm quality. Changes in sperm function and semen ROS levels following three months of oral LAL therapy were compared between participants with baseline seminal normal ROS (≤10RLU/SEC/106 sperm; n = 29) and High ROS (>10 RLU/SEC/106 sperm; n = 15) levels measured using an established colorimetric-luminol method. RESULTS: In normal ROS group, sperm function did not change following LAL therapy. In high ROS group, LAL therapy reduced semen ROS fivefold, increased sperm count by 50% (mean count in mill/ml: 21.5 + 7.2, baseline; 32.6 + 9.5, post-treatment, P = .0005), and total and progressive sperm motility each by 30% (mean total sperm motility in % 29.8 + 5.0, baseline: 39.4 + 6.2, post-treatment, P = .004; mean progressive sperm motility in % 23.1 + 4.6, baseline: 30.0 + 5.5, post-treatment, P = .014 vs. baseline). CONCLUSIONS: We report for the first time that LAL only improves sperm quality in infertile men who have baseline high-ROS levels prior to treatment. These data have important potential implications for couples with male infertility and their clinicians.

The molecular epidemiology of Huntington disease is related to intermediate allele frequency and haplotype in the general population.

Huntington disease (HD) is the most common monogenic neurodegenerative disorder in populations of European ancestry, but occurs at lower prevalence in populations of East Asian or black African descent. New mutations for HD result from CAG repeat expansions of intermediate alleles (IAs), usually of paternal origin. The differing prevalence of HD may be related to the rate of new mutations in a population, but no comparative estimates of IA frequency or the HD new mutation rate are available. In this study, we characterize IA frequency and the CAG repeat distribution in fifteen populations of diverse ethnic origin. We estimate the HD new mutation rate in a series of populations using molecular IA expansion rates. The frequency of IAs was highest in Hispanic Americans and Northern Europeans, and lowest in black Africans and East Asians. The prevalence of HD correlated with the frequency of IAs by population and with the proportion of IAs found on the HD-associated A1 haplotype. The HD new mutation rate was estimated to be highest in populations with the highest frequency of IAs. In European ancestry populations, one in 5,372 individuals from the general population and 7.1% of individuals with an expanded CAG repeat in the HD range are estimated to have a molecular new mutation. Our data suggest that the new mutation rate for HD varies substantially between populations, and that IA frequency and haplotype are closely linked to observed epidemiological differences in the prevalence of HD across major ancestry groups in different countries.

Propofol sedation does not improve measures of colonoscopy quality but increase cost - findings from a large population-based cohort study.

Background: Propofol is often used for sedation during colonoscopy. We assessed the impact of propofol sedation on colonoscopy related quality metrics and cost in a population-based cohort study. Methods: All colonoscopies performed at 21 hospitals in the province of Ontario, Canada, during an 18-month period, from April 1, 2017 to October 31, 2018, using either propofol or conscious sedation were evaluated. The primary outcome was adenoma detection rate (ADR) and secondary outcomes were sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), cecal intubation rate (CIR), and perforation rate. Binary outcomes were assessed using a modified Poisson regression model adjusted for clustering and potential confounders based on patient, procedure, and physician characteristics. Findings: A total of 46,634 colonoscopies were performed, of which 16,408 (35.2%) received propofol and 30,226 (64.8%) received conscious sedation. Compared to conscious sedation, the use of propofol was associated with a lower ADR (24.6% vs. 27.0%, p < 0.0001) but not ssPDR (5.0% vs. 4.7%, p = 0.26), PDR (40.5% vs 40.4%, p = 0.79), CIR (97.1% vs. 96.8%, p = 0.15) or perforation rate (0.04% vs. 0.06%, p = 0.45). On multi-variable analysis, propofol sedation was not associated with any differences in ADR (RR = 0.90, 95% CI 0.74-1.10, p = 0.30), ssPDR (RR = 1.20, 95% CI 0.90-1.60, p = 0.22), PDR (RR = 1.00, 95% CI 0.90-1.11, p = 0.99), or CIR (RR = 1.00, 95% CI 0.80-1.26, p = 0.99). The additional cost associated with propofol sedation was $12,730,496 for every 100,000 cases. Interpretation: The use of propofol sedation was not associated with improved colonoscopy related quality metrics but increased costs. The routine use of propofol for colonoscopy should be reevaluated. Funding: None.

Clinical, Endoscopic, and Radiological Effectiveness of Ustekinumab in Bio-naïve Versus Bio-experienced Patients With Crohn's Disease: Real-world Experience From a Large Canadian Center.

INTRODUCTION: With the expanding therapeutic armamentarium for inflammatory bowel disease (IBD), real-world data may help inform drug positioning. We assessed clinical, endoscopic, imaging, and biochemical response/remission outcomes in patients with Crohn's disease (CD) treated with ustekinumab in a large Canadian IBD center. METHODS: A retrospective cohort study of CD patients was treated with ustekinumab. Clinical, endoscopic, radiological, and biochemical response and remission outcomes were stratified by prior biologic exposure status. Hazard ratios for biologic exposure status were estimated using Cox proportional hazard models and subgroup-specific incidence rates for healing. RESULTS: A total of 231 patients (55.9% female, median 45.8 years) were identified as receiving ustekinumab during the study period, with 2 patients subsequently excluded (N = 229). Of these patients, 79.0% (181 of 229) were bio-experienced, with 38.7% (70 of 181) having failed 1 biologic and 61.3% (111 of 181) having failed ≥2 biologics. At 3 months of follow-up after induction, clinical remission (Harvey-Bradshaw Index ≤4) was achieved by 59.1% (62 of 105) of bio-experienced patients and 79.4% (27 of 34) of bio-naïve patients (relative risk [RR], 1.34; 95% CI, 1.06-1.70; P = .013). Endoscopic remission (absence of mucosal ulcers) was achieved in 37.9% (33 of 87) cases. Rate of endoscopic healing (either endoscopic response or remission) per 1000 person-months was 72.7 (95% CI, 42.4-125.1) and 50.2 (37.9-66.4); and the median time to endoscopic response was 8.4 months (95% CI, 6.4-9.8) and 15.4 months (95% CI, 10.3-17.9) in bio-naïve vs bio-experienced patients, respectively. Imaging response/remission and steroid-free remission rates were higher in bio-naïve patients. CONCLUSION: In this large real-world cohort of CD patients with complex phenotypes and high rates of prior biologic exposure, we observed that ustekinumab was effective and safe with higher rates of improvement in bio-naïve subjects across a range of end points.

In this large real-world study of patients with Crohn's Disease treated with ustekinumab, we observed high rates of clinical, endoscopic, radiological, and biochemical response and remission rates. Effectiveness was greater in bio-naïve compared with bio-experienced patients.

Placebo Response Rates in Randomized Controlled Trials for Perianal Crohn's Disease: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: Perianal fistulizing disease is a common complication of Crohn's disease [CD], for which new therapies are urgently needed. To assist the design of clinical trials for novel therapeutics, we conducted a systematic review and meta-analysis of randomised controlled trials [RCTs] to quantify placebo rates and identify factors influencing them in perianal CD [pCD]. METHODS: We searched MEDLINE, Embase and CENTRAL from inception to June 2021. Eligible studies were placebo-controlled trials of pharmacological interventions for pCD. Placebo fistula response and remission rates for induction and maintenance trials were extracted and pooled using a random-effects model. Mixed-effects meta-regression was used to evaluate the impact of patient and study-level characteristics on point estimates. RESULTS: In 17 RCTs [13 induction, five maintenance] the pooled placebo fistula response and remission rate for induction trials was 25% (95% confidence interval [CI] 17-36%) and 17% [95% CI 11-25%], respectively. For maintenance trials, the pooled placebo fistula response and remission rate was 23% [95% CI 17-32%] and 19% [95% CI 14-25%], respectively. Trials enrolling patients with less disease activity and a higher proportion with ileal predominant disease were associated with significantly higher placebo response rates. Trials originating in Europe [compared to North America], therapies requiring perianal injection and a longer timepoint to measure remission were associated with higher placebo remission rates. CONCLUSIONS: Placebo response and remission rates in pCD trials are influenced by patient and disease-related factors, as well as the type of intervention being studied. These contemporary rates will inform trial design for novel therapeutics.

Access to unpublished protocols and statistical analysis plans of randomised trials.

BACKGROUND: Access to protocols and statistical analysis plans (SAPs) increases the transparency of randomised trial by allowing readers to identify and interpret unplanned changes to study methods, however they are often not made publicly available. We sought to determine how often study investigators would share unavailable documents upon request. METHODS: We used trials from two previously identified cohorts (cohort 1: 101 trials published in high impact factor journals between January and April of 2018; cohort 2: 100 trials published in June 2018 in journals indexed in PubMed) to determine whether study investigators would share unavailable protocols/SAPs upon request. We emailed corresponding authors of trials with no publicly available protocol or SAP up to four times. RESULTS: Overall, 96 of 201 trials (48%) across the two cohorts had no publicly available protocol or SAP (11/101 high-impact cohort, 85/100 PubMed cohort). In total, 8/96 authors (8%) shared some trial documentation (protocol only [n = 5]; protocol and SAP [n = 1]; excerpt from protocol [n = 1]; research ethics application form [n = 1]). We received protocols for 6/96 trials (6%), and a SAP for 1/96 trial (1%). Seventy-three authors (76%) did not respond, 7 authors responded (7%) but declined to share a protocol or SAP, and eight email addresses were invalid (8%). A total of 329 emails were sent (an average of 41 emails for every trial which sent documentation). After emailing authors, the total number of trials with an available protocol increased by only 3%, from 52% in to 55%. CONCLUSIONS: Most study investigators did not share their unpublished protocols or SAPs upon direct request. Alternative strategies are needed to increase transparency of randomised trials and ensure access to protocols and SAPs.

The Risk-Reducing Effect of Aspirin in Lynch Syndrome Carriers: Development and Evaluation of an Educational Leaflet.

Carriers of germline mutations in genes associated with Lynch syndrome are at increased risk for colorectal, endometrial, ovarian, and other cancers. There is evidence that daily consumption of aspirin may reduce cancer risk in these individuals. There is a need for educational resources to inform carriers of the risk-reducing effects of aspirin or to support decision-making. An educational leaflet describing the risks and benefits of using aspirin as risk-reducing medicine in carriers of Lynch-syndrome-related mutations is developed and pilot tested in 2017. Carriers are ascertained through a familial cancer clinic and surveyed using a mailed, self-administered questionnaire. The leaflet is highly rated for its content, clarity, length, relevance, and visual appeal by more than 70% of the participants. Most participants (91%) report "a lot" or "quite a bit" of improvement in perceived understanding in knowledge about who might benefit from taking aspirin, its benefits, how long to take it, the reduction in bowel cancer risk, and the optimal dosage. A few (14%) participants seek more information on the dosage of aspirin. This leaflet will be useful as an aid to facilitate discussion between patients and their health care professionals about the use of aspirin as a risk-reducing medication.

Association of Trainee Participation in Colonoscopy Procedures With Quality Metrics.

Importance: Trainees routinely participate in colonoscopy procedures, yet whether their involvement is positively or negatively associated with procedural quality is unknown because prior studies involved small number of trainees and/or supervisors, lacked generalizability, and/or failed to adjust for potential confounders. Objective: To assess the association between trainee participation and colonoscopy quality metrics. Design, Setting, and Participants: This multicenter population-based cohort study was conducted at 21 academic and community hospitals between April 1, 2017, and October 31, 2018, among consecutive adult patients undergoing colonoscopy. Procedures performed by endoscopists who did not supervise trainees were excluded. Statistical analysis was performed from April 3, 2017, to October 31, 2018. Exposure: Participation by a trainee, defined as a resident or fellow enrolled in a gastroenterology or general surgery training program. Main Outcomes and Measures: The primary outcome was the adenoma detection rate (ADR), and secondary outcomes were sessile serrated polyp detection rate (ssPDR), polyp detection rate (PDR), cecal intubation rate (CIR), and perforation rate. Results: A total of 35 499 colonoscopies (18 989 women [53.5%]; mean [SD] patient age, 60.0 [14.1] years) were performed by 71 physicians (mean [SD] time in practice, 14.0 [9.3] years); 5941 colonoscopies (16.7%) involved trainees. There were no significant differences in the ADR (26.4% vs 27.3%; P = .19), CIR (96.7% vs 97.2%; P = .07), and perforation rate (0.05% vs 0.06%; P = .82) when trainees participated vs when they did not participate, whereas the the ssPDR (4.4% vs 5.2%; P = .009) and PDR (39.2% vs 42.0%; P < .001) were significantly lower when trainees participated vs when they did not. After adjustment for potential confounders, the ADR (risk ratio [RR], 0.97; 95% CI, 0.91-1.03; P = .30), PDR (RR, 0.98; 95% CI, 0.93-1.04; P = .47), and CIR (RR, 0.93; 95% CI, 0.78-1.10; P = .38) were not associated with trainee participation, although the ssPDR remained significantly lower (RR, 0.79; 95% CI, 0.64-0.98; P = .03). Conclusions and Relevance: This study suggests that trainee involvement during colonoscopy was associated with reduced ssPDR but not other colonoscopy outcome measures. Extra care should be exercised when examining the right colon when trainees are involved.

Evaluation for associations amongst Giardia duodenalis assemblages and diarrhea in dogs.

Giardia duodenalis is a species complex comprising at least eight assemblages. Most dogs harbor the host-adapted assemblages C and D and approximately 30 % harbor the zoonotic assemblages. Humans and dogs with giardiosis can exhibit a variety of clinical manifestations ranging from the absence of clinical signs to acute or chronic diarrhea. Human studies report conflicting results concerning associations between clinical signs and assemblage type. The objective of this study was to use results of molecular and phylogenetic analyses to evaluate associations between G. duodenalis assemblages and diarrhea in client-owned dogs from the United States. Fecal samples that were positive for Giardia cysts were classified as normal or diarrheal. Samples were analyzed by PCR assays of the beta-giardin (bg), glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) genes. Sequences of the three genes were analyzed by BLAST analysis and phylogenetic analysis was performed by Neighbor-Joining analysis. Two hundred and eighty-eight Giardia-positive fecal samples were evaluated by the three PCRs. One or more genes were amplified from 95 normal samples and 93 diarrheal samples, 27 samples were positive for one or more genes but could not be sequenced due to low quality DNA, and 73 samples tested negative. Ninety seven percent of the samples (182/188) in both the diarrheal and normal groups typed as dog-specific assemblages (D or C) by at least one gene. Phylogenetic analysis of the three genes placed the isolates from assemblages A, B, C and D separated from each other with strong bootstrap support. Diarrhea was not associated with the Giardia assemblage or other parasitic co-infection in this sample set. Other factors, such as the role of gut microbiota in giardiosis should be considered in future studies.

A randomized controlled trial of high volume simethicone to improve visualization during capsule endoscopy.

BACKGROUND: The optimal dose of simethicone before capsule endoscopy is unknown. Prior studies have reported inconsistent cleansing, with some showing improved visualization only in the proximal small intestine. We hypothesized a higher volume of simethicone may improve cleansing and diagnostic yield, especially in the distal small bowel. METHODS: A phase III randomized controlled trial was conducted comparing high volume (1125 mg simethicone in 750 ml water) versus standard volume (300 mg simethicone in 200 ml water) solutions, both at 1.5 mg/ml. The primary outcome was adequate bowel preparation, defined as a KOrea-CanaDA (KODA) score >2.25, overall and stratified by the proximal and distal half of the small bowel. Secondary outcomes included mean KODA score, diagnostic yield, completion rate, and adverse events. All analyses were intention-to-treat. RESULTS: A total of 167 patients were randomized (mean (SD) age 58.7 (15.7), 54% female) and the most common indication was obscure gastrointestinal bleeding (71.7%). Adequate cleansing was achieved in 39 (50%) patients in the high volume group and in 39 (48%) patients in the standard volume group (RR 1.04, 95% CI 0.76-1.43, p = 0.82), with no differences observed in the proximal half (71% vs 64%, p = 0.40) or the distal half -of the small bowel (36% vs. 37%, p = 0.88). There was no differences in the mean (SD) KODA score (2.20 (0.41) vs. 2.18 (0.44), p = 0.73), diagnostic yields (53% vs. 56%, p = 0.71), or completion rates (both 95%). One adverse event, nausea, occurred in the control group. CONCLUSION: High volume simethicone does not improve visualization during capsule endoscopy. CLINICAL TRIAL REGISTRATION: Clinical trial: NCT02334631.

H3K4 Trimethylation Is Required for Postnatal Pancreatic Endocrine Cell Functional Maturation.

During pancreas development, endocrine progenitors differentiate into the islet cell subtypes, which undergo further functional maturation in postnatal islet development. In islet ß-cells, genes involved in glucose-stimulated insulin secretion are activated, and glucose exposure increases the insulin response as ß-cells mature. We investigated the role of H3K4 trimethylation in endocrine cell differentiation and functional maturation by disrupting TrxG complex histone methyltransferase activity in mouse endocrine progenitors. In the embryo, genetic inactivation of TrxG component Dpy30 in NEUROG3+ cells did not affect the number of endocrine progenitors or endocrine cell differentiation. H3K4 trimethylation was progressively lost in postnatal islets, and the mice displayed elevated nonfasting and fasting glycemia as well as impaired glucose tolerance by postnatal day 24. Although postnatal endocrine cell proportions were equivalent to controls, islet RNA sequencing revealed a downregulation of genes involved in glucose-stimulated insulin secretion and an upregulation of immature ß-cell genes. Comparison of histone modification enrichment profiles in NEUROG3+ endocrine progenitors and mature islets suggested that genes downregulated by loss of H3K4 trimethylation more frequently acquire active histone modifications during maturation. Taken together, these findings suggest that H3K4 trimethylation is required for the activation of genes involved in the functional maturation of pancreatic islet endocrine cells.

Safety of "hot" and "cold" site admissions within a high-volume urology department in the United Kingdom at the peak of the COVID-19 pandemic.

OBJECTIVES: To determine the safety of urological admissions and procedures during the height of the COVID-19 pandemic using "hot" and "cold" sites. The secondary objective is to determine risk factors of contracting COVID-19 within our cohort. PATIENTS AND METHODS: A retrospective cohort study of all consecutive patients admitted from March 1 to May 31, 2020 at a high-volume tertiary urology department in London, United Kingdom. Elective surgery was carried out at a "cold" site requiring a negative COVID-19 swab 72-hours prior to admission and patients were required to self-isolate for 14-days preoperatively, while all acute admissions were admitted to the "hot" site.Complications related to COVID-19 were presented as percentages. Risk factors for developing COVID-19 infection were determined using multivariate logistic regression analysis. RESULTS: A total of 611 patients, 451 (73.8%) male and 160 (26.2%) female, with a median age of 57 (interquartile range 44-70) were admitted under the urology team; 101 (16.5%) on the "cold" site and 510 (83.5%) on the "hot" site. Procedures were performed in 495 patients of which eight (1.6%) contracted COVID-19 postoperatively with one (0.2%) postoperative mortality due to COVID-19. Overall, COVID-19 was detected in 20 (3.3%) patients with two (0.3%) deaths. Length of stay was associated with contracting COVID-19 in our cohort (OR 1.25, 95% CI 1.13-1.39). CONCLUSIONS: Continuation of urological procedures using "hot" and "cold" sites throughout the COVID-19 pandemic was safe practice, although the risk of COVID-19 remained and is underlined by a postoperative mortality.