Metformin, a biguanide derivate, has pleiotropic effects beyond glucose reduction, including improvement of lipid profiles and lowering microvascular and macrovascular complications associated with type 2 diabetes mellitus (T2DM). These effects have been ascribed to adenosine monophosphate-activated protein kinase (AMPK) activation in the liver and skeletal muscle. However, metformin effects are not attenuated when AMPK is knocked out and intravenous metformin is less effective than oral medication, raising the possibility of important gut pharmacology. We hypothesized that the pharmacology of metformin includes alteration of bile acid recirculation and gut microbiota resulting in enhanced enteroendocrine hormone secretion. In this study we evaluated T2DM subjects on and off metformin monotherapy to characterize the gut-based mechanisms of metformin. Subjects were studied at 4 time points: (i) at baseline on metformin, (ii) 7 days after stopping metformin, (iii) when fasting blood glucose (FBG) had risen by 25% after stopping metformin, and (iv) when FBG returned to baseline levels after restarting the metformin. At these timepoints we profiled glucose, insulin, gut hormones (glucagon-like peptide-1 (GLP-1), peptide tyrosine-tyrosine (PYY) and glucose-dependent insulinotropic peptide (GIP) and bile acids in blood, as well as duodenal and faecal bile acids and gut microbiota. We found that metformin withdrawal was associated with a reduction of active and total GLP-1 and elevation of serum bile acids, especially cholic acid and its conjugates. These effects reversed when metformin was restarted. Effects on circulating PYY were more modest, while GIP changes were negligible. Microbiota abundance of the phylum Firmicutes was positively correlated with changes in cholic acid and conjugates, while Bacteroidetes abundance was negatively correlated. Firmicutes and Bacteroidetes representation were also correlated with levels of serum PYY. Our study suggests that metformin has complex effects due to gut-based pharmacology which might provide insights into novel therapeutic approaches to treat T2DM and associated metabolic diseases.Trial Registration: www.ClinicalTrials.gov NCT01357876

Objective: To identify cell types in the male and female reproductive systems at risk for SARS-CoV-2 infection because of the expression of host genes and proteins used by the virus for cell entry. Design: Descriptive analysis of transcriptomic and proteomic data. Setting: Academic research department and clinical diagnostic laboratory. Patient(s): Not applicable (focus was on previously generated gene and protein expression data). Intervention(s): None. Main Outcome Measure(s): Identification of cell types coexpressing the key angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) genes and proteins as well as other candidates potentially involved in SARS-CoV-2 cell entry. Result(s): On the basis of single-cell RNA sequencing data, coexpression of ACE2 and TMPRSS2 was not detected in testicular cells, including sperm. A subpopulation of oocytes in nonhuman primate ovarian tissue was found to express ACE2 and TMPRSS2, but coexpression was not observed in ovarian somatic cells. RNA expression of TMPRSS2 in 18 samples of human cumulus cells was shown to be low or absent. There was general agreement between publicly available bulk RNA and protein datasets in terms of ACE2 and TMPRSS2 expression patterns in testis, ovary, endometrial, and placental cells. Conclusion(s):These analyses suggest that SARS-CoV-2 infection is unlikely to have long-term effects on male and female reproductive function. Although the results cannot be considered definitive, they imply that procedures in which oocytes are collected and fertilized in vitro are associated with very little risk of viral transmission from gametes to embryos and may indeed have the potential to minimize exposure of susceptible reproductive cell types to infection in comparison with natural conception. (Fertil Steril Ò 2020;114:33-43. Ó2020 by American Society for Reproductive Medicine.) El resumen está disponible en Español al final del artículo.

Determining the genetic characteristics of Staphylococcus aureus is important for better understanding of the global and dynamic epidemiology of this organism as we witness the emergence and spread of virulent and antibiotic-resistant clones. We genotyped 292 S. aureus isolates (105 methicillin resistant and 187 methicillin susceptible) using a combination of pulsed-field gel electrophoresis, multilocus sequence typing, and SCCmec typing. In addition, S. aureus isolates were tested for the presence of the Panton-Valentine leukocidin (PVL) genes. Isolates were recovered from patients with uncomplicated skin infections in 10 different countries during five phase III global clinical trials of retapamulin, a new topical antibiotic agent. The most common methicillin-resistant clone had multilocus sequence type 8, pulsed-field type USA300, and SCCmec type IV and possessed the PVL genes. This clone was isolated exclusively in the United States. The most common PVLpositive, methicillin-susceptible clone had multilocus sequence type 121 and pulsed-field type USA1200. This clone was found primarily in South Africa and the Russian Federation. Other clones were found at lower frequencies and were limited in their geographic distribution. Overall, considerable genetic diversity was observed within multilocus sequence type clonal complexes and pulsed-field types.

e GSK2251052, a novel leucyl-tRNA synthetase (LeuRS) inhibitor, was in development for the treatment of infections caused by multidrug-resistant Gram-negative pathogens. In a phase II study (study LRS114688) evaluating the efficacy of GSK2251052 in complicated urinary tract infections, resistance developed very rapidly in 3 of 14 subjects enrolled, with >32-fold increases in the GSK2251052 MIC of the infecting pathogen being detected. A fourth subject did not exhibit the development of resistance in the baseline pathogen but posttherapy did present with a different pathogen resistant to GSK2251052. Whole-genome DNA sequencing of Escherichia coli isolates collected longitudinally from two study LRS114688 subjects confirmed that GSK2251052 resistance was due to specific mutations, selected on the first day of therapy, in the LeuRS editing domain. Phylogenetic analysis strongly suggested that resistant Escherichia coli isolates resulted from clonal expansion of baseline susceptible strains. This resistance development likely resulted from the confluence of multiple factors, of which only some can be assessed preclinically. Our study shows the challenges of developing antibiotics and the importance of clinical studies to evaluate their effect on disease pathogenesis. (These studies have been registered at ClinicalTrials.gov under registration no. NCT01381549 for the study of complicated urinary tract infections and registration no. NCT01381562 for the study of complicated intra-abdominal infections.) A pproximately 5% of patients admitted to hospitals in the United States develop nosocomial infections that increase not only patient mortality (1) but also hospitalization time and cost of treatment (2, 3). In the United States, Gram-negative bacterial pathogens, such as Escherichia coli, Klebsiella pneumoniae/Klebsiella oxytoca, Pseudomonas aeruginosa, and Acinetobacter baumannii, are responsible for 35% of the most common hospitalacquired infections (HAIs) or conditions, including urinary tract infections (UTIs), pneumonia, and surgical site and bloodstream infections. Furthermore, Ͼ70% of the bacteria causing HAIs are resistant to at least one of the most commonly used antibiotics (4-6). The continuing emergence of resistance has compromised treatment options for Gram-negative bacterial pathogens and forced the use of polymyxins (7), an old antibiotic class with nephrotoxicity issues. Despite the clear need for alternatives to treat these multidrug-resistant life-threatening pathogens, a review of the antibacterial pipeline reveals a scarcity of new antibiotic candidates (8).Aminoacyl-tRNA synthetases (AaRSs) play an essential role in protein synthesis (9) and have been clinically validated to be antibacterial targets of mupirocin (10), an inhibitor of isoleucyltRNA synthetase that has been successfully used since 1985 in the topical treatment of Gram-positive bacterial skin infections (11). Their ubiquitous nature, high degree of conservation within a broad spectrum of bacterial species, and considerable divergence...

Introduction Metformin and glucagon‐like peptide‐1 ( GLP ‐1) agonists are widely used for treating type two diabetes mellitus (T2 DM ). While recent studies suggest these drugs might modify the gastrointestinal tract ( GIT ) microbiome, further confirmation is required from human clinical trials. Materials and methods Here, we compare, in patients with T2 DM , the effects of metformin (n = 18 subjects) and liraglutide (n = 19), a GLP ‐1 agonist, on their GIT microbiomes over a 42 day period (n = 74 samples) using 16S ribosomal RNA ( rRNA ) sequencing. Results We found that these drugs had markedly different effects on the microbiome composition. At both baseline and Day 42, subjects taking metformin had a significant increase (Baseline adj. P = .038, Day 42 adj. P = .041) in the relative abundance of the bacterial genus Sutterella , whereas liraglutide dosing is associated with a significant increase (Baseline adj. P = .048, Day 42 adj. P = .003) in the genus Akkermansia , a GIT bacteria positively associated with gut barrier homoeostasis. Bacteroides and Akkermansia relative abundances were also significantly associated with duration of subject diabetes (adj P < .05). Specifically, there was a significantly higher abundance of Akkermansia in subjects with short and medium durations than those with long duration of diabetes. Discussion To our knowledge, this is the first report of GLP ‐1 agonist‐associated changes in the human microbiome and its differentiating effects to metformin. Our study suggests that modulation of the GIT microbiome is a potentially important component in the mechanism of action of these drugs.

Background: Estimates of energy intake are required for an understanding of growth and disease; however, few methods of energy intake in children have been validated. Objective: Our objective was to validate energy intake estimated by the Youth-Adolescent Food-Frequency Questionnaire (YAQ) against the criterion total energy expenditure (TEE) by doubly labeled water (DLW). Design: Twenty-three boys and 27 girls (8.6-16.2 y of age) completed the YAQ and TEE measurements in 1 y. Results: Energy intake by the YAQ (10.03 ± 3.12 MJ) and energy expenditure by DLW (9.84 ± 1.79 MJ) were similar (P = 0.91) with large lower (Ϫ6.30 MJ) and upper (6.67 MJ) ± 2 SD limits of agreement. When within-subject CVs of repeated measures of the DLW and YAQ methods were used, 25 of the 50 subjects were deemed to have misreported their energy intake. The discrepancy in energy intake (YAQ -TEE) was related to body weight (r = Ϫ0.25, P = 0.077) and percentage body fat (r = Ϫ0.24, P = 0.09) but not to age (r = Ϫ0.07, P = 0.63) or the time between measures. From logistic regression, fatter boys were more likely to underreport energy intake than were fatter girls. Conclusion:The YAQ provides an accurate estimation of mean energy intake for a group but not for an individual.Am J Clin Nutr 2000;72:1455-60. KEY WORDSChildren, adolescents, youth-adolescent questionnaire, Youth-Adolescent Food-Frequency Questionnaire, food-frequency questionnaire, energy expenditure, energy intake, doubly labeled water INTRODUCTIONDietary intake influences normal growth, the development and progression of obesity, and many other conditions. Therefore, the ability to accurately measure energy and nutrient intake in individuals and populations is of great importance. Focus on nutritional intake in the first decades of life is particularly important because many lifelong nutritional habits may be established during childhood and adolescence (1, 2). Measurement of energy and nutrient intake in youngsters is challenging because of their lower literacy levels, cognitive and memory differences, knowledge deficits about food and food preparation techniques, and a general lack of interest in the subject matter (3).Baranowski and Domel (4) found that by age 10 y, most children are aware of the foods they have eaten and are able to give accurate information about their diet. Youth aged 9-18 y have shown the ability to complete a self-administered food-frequency questionnaire with reasonable consistency in responses over time (5). The accuracy of estimation of energy intake provided by food-frequency questionnaires may be assessed by comparison with doubly labeled water (DLW)-derived measurements of total energy expenditure (TEE). DLW-derived TEE is considered a criterion method for determining energy expenditure. Several studies showed that children and adolescents underreport their energy intake compared with their TEE (6-12). The subject's body composition, TEE, and age are significant factors in the magnitude of underreporting; fatter (6, 7, 10, 11) and older (6...

Varicella-zoster virus (VZV) is a herpesvirus and is the causative agent of chicken pox (varicella) and shingles (herpes zoster)

Recently, the use of three-dimensional neural tissues cultured in vitro and called "cerebral organoids" has advanced recapitulation of neural development and disease modeling studies. Along with such advances, cerebral organoid research, and associated concerns call for the elucidation of two points: (1) how cerebral organoid research is currently progressing and the future directions it is likely to take, especially in functional assessment of organoids, and (2) how we should solve ethical issues of possible consciousness in cerebral organoid research. This paper aims first to explore these two issues, and then to present implications and prospects for future cerebral organoid research.