593 research outputs found

    Discovery of Dermorphin-Based Affinity Labels with Subnanomolar Affinity for Mu Opioid Receptors+

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    A series of potent electrophilic affinity labels (IC50 = 0.1-5 nM) containing either a bromoacetamide or isothiocyanate based on the mu opioid receptor (MOR) selective peptide dermorphin were prepared. All four analogs exhibited wash resistant inhibition of [3H]DAMGO binding at subnanomolar to nanomolar concentrations, suggesting that these analogs bind covalently to MOR. To our knowledge these peptides are the highest affinity peptide-based affinity labels for MOR reported to date

    Estrogenic modulation of uropathogenic Escherichia coli infection pathogenesis in a murine menopause model

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    Recurrent urinary tract infections (UTIs), primarily caused by uropathogenic Escherichia coli (UPEC), annually affect over 13 million patients in the United States. Menopausal women are disproportionally susceptible, suggesting estrogen deficiency is a significant risk factor for chronic and recurrent UTI. How estrogen status governs susceptibility to UTIs remains unknown, and whether hormone therapy protects against UTIs remains controversial. Here, we used a mouse model of surgical menopause by ovariectomy and demonstrate a protective role for estrogen in UTI pathogenesis. We found that ovariectomized mice had significantly higher bacteriuria, a more robust inflammatory response, and increased production of the proinflammatory cytokine interleukin-6 (IL-6) upon UPEC infection compared to sham-operated controls. We further show that response of the urothelial stem cell niche to infection, normally activated to restore homeostasis after infection, was aberrant in ovariectomized mice with defective superficial urothelial cell differentiation. Finally, UPEC-infected ovariectomized mice showed a significant increase in quiescent intracellular bacterial reservoirs, which reside in the urothelium and can seed recurrent infections. Importantly, this and other ovariectomy-induced outcomes of UTI were reversible upon estrogen supplementation. Together, our findings establish ovariectomized mice as a model for UTIs in menopausal women and pinpoint specific events during course of infection that are most susceptible to estrogen deficiency. These findings have profound implications for the understanding of the role of estrogen and estrogen therapy in bladder health and pathogen defense mechanisms and open the door for prophylaxis for menopausal women with recurrent UTIs

    Assessment of gastroesophageal reflux symptoms and sleep quality among women in the Nurses\u27 Health Study II

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    IMPORTANCE: Limited data exist on the association of gastroesophageal reflux (GER) symptoms with sleep quality. OBJECTIVE: To prospectively investigate the association between GER symptoms and sleep quality. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study included data from the Nurses\u27 Health Study II of female nurses in the US. Participants self-reported the frequency and duration of GER symptoms beginning June 2005, with updates every 4 years through June 2015. Follow-up was completed June 2019, and data were analyzed from November 15, 2022, to June 4, 2023. EXPOSURES: Frequency and duration of GER symptoms. MAIN OUTCOMES AND MEASURES: Poor sleep quality was assessed in 2017 through a modified Pittsburgh Sleep Quality Index, which included difficulty in falling asleep, restlessness of sleep, daytime sleepiness, sleep disturbance, and sleep duration. Relative risk (RR) for poor sleep quality and individual components of poor sleep quality was estimated according to the frequency and duration of GER symptoms. RESULTS: Among 48 536 women (median age, 59 years [range, 48-69 years]), 7929 (16.3%) developed poor sleep quality during 4 years of follow-up. Compared with those with GER symptoms less than once a month, the multivariable RR for poor sleep quality among women with GER symptoms more than once a week was 1.53 (95% CI, 1.45-1.62). Women who had GER symptoms once or more a week for more than 7 years had an RR of 1.36 (95% CI, 1.30-1.43) compared with women who had not had GER symptoms once or more a week. The frequency and duration of GER symptoms were significantly associated with each individual component of poor sleep quality; for example, the multivariable RRs for GER symptoms 2 or more times per week compared with no GER symptoms were 1.49 (95% CI, 1.39-1.58) for difficulty in falling asleep, 1.47 (95% CI, 1.39-1.56) for excessive daytime sleepiness, and 1.44 (95% CI, 1.36-1.53) for restlessness of sleep. CONCLUSIONS AND RELEVANCE: In this prospective cohort study of female nurses in the Nurses\u27 Health Study II, the frequency and duration of GER symptoms were associated with subsequent risk of poor sleep quality. The findings suggest that effective treatment of GER disease may be important not only for improvement of symptoms but also for the reduction of comorbidities associated with poor sleep quality

    COVID-19: How Do We Stay Safe?

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    Multiple effects of silymarin on the hepatitis C virus lifecycle

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    Silymarin, an extract from milk thistle (Silybum marianum), and its purified flavonolignans have been recently shown to inhibit hepatitis C virus (HCV) infection, both in vitro and in vivo. In the current study, we further characterized silymarin's antiviral actions. Silymarin had antiviral effects against hepatitis C virus cell culture (HCVcc) infection that included inhibition of virus entry, RNA and protein expression, and infectious virus production. Silymarin did not block HCVcc binding to cells but inhibited the entry of several viral pseudoparticles (pp), and fusion of HCVpp with liposomes. Silymarin but not silibinin inhibited genotype 2a NS5B RNA-dependent RNA polymerase (RdRp) activity at concentrations 5 to 10 times higher than required for anti-HCVcc effects. Furthermore, silymarin had inefficient activity on the genotype 1b BK and four 1b RDRPs derived from HCV-infected patients. Moreover, silymarin did not inhibit HCV replication in five independent genotype 1a, 1b, and 2a replicon cell lines that did not produce infectious virus. Silymarin inhibited microsomal triglyceride transfer protein activity, apolipoprotein B secretion, and infectious virion production into culture supernatants. Silymarin also blocked cell-to-cell spread of virus. CONCLUSION: Although inhibition of in vitro NS5B polymerase activity is demonstrable, the mechanisms of silymarin's antiviral action appear to include blocking of virus entry and transmission, possibly by targeting the host cell

    Blood transcriptome responses to PFOA and GenX treatment in the marsupial biomedical model Monodelphis domestica

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    Introduction: Perfluoroalkyl and poly-fluoroalkyl substances (PFASs) are widely used in industrial and consumer products. Due to their environmental persistence and bioaccumulation, PFASs can be found in the blood of humans and wild animals all over the world. Various fluorinated alternatives such as GenX have been developed to replace the long-chain PFASs, but there is limited information about their potential toxicity. Methods:The current study developed blood culture protocols to assess the response to toxic compounds in the marsupial, Monodelphis domestica. After whole-blood culture conditions were tested and optimized, changes in gene expression in response to PFOA and GenX treatment were assessed. Results: More than 10,000 genes were expressed in the blood transcriptomes with and without treatment. Both PFOA and GenX treatment led to significant changes in the whole blood culture transcriptomes. A total of 578 and 148 differentially expressed genes (DEGs) were detected in the PFOA and GenX treatment groups, 32 of which overlapped. Pathway enrichment analysis revealed that DEGs involved in developmental processes were upregulated after PFOA exposure, while those enriched for metabolic and immune system processes were downregulated. GenX exposure upregulated genes associated with fatty acid transport pathways and inflammatory processes, which is consistent with previous studies using rodent models. Discussion: To our knowledge, this study is the first to investigate the effect of PFASs in a marsupial model. The findings provide supportive evidence for significant transcriptomic alterations, suggesting that this mammalian model may provide a mechanism for exploring the potential toxicity of PFOA and GenX

    The “problem” of teacher quality: exploring challenges and opportunities in developing teacher quality during the Covid-19 global pandemic in England

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    Teachers and teacher education are often presented as “problems” to be solved, with policy solutions that focus on ways to make teachers “better” and improve teacher “quality” by introducing prescriptive strategies. We investigate the ways Covid-19-related changes to university and school-based facets of Initial Teacher Education (ITE) in England influence teacher quality in relation to both student teachers and early career teachers, working in secondary schools. Drawing on 34 interviews with school leaders, school mentors and ITE tutors, we critically explore the ways in which teacher quality was developed through key aspects of teachers’ pedagogy and practice during the pandemic crisis when schools were closed and teaching moved online. Our findings show that the pandemic crisis has highlighted the different facets of teacher quality which arguably disrupt narrow and prescriptive understandings of what constitutes “quality” in policy terms. Although there were many instances of challenge in the development of new and student teachers, our data also shows how ITE tutors, school mentors and leaders responded creatively to the crisis. Participants highlighted the opportunities afforded by the pandemic to develop diverse and innovative pedagogies and practice, enhance students’ subject knowledge, as well as overcome some of the challenges in other areas of pedagogy and practice. Furthermore, the study shows that teacher quality was not substantially reduced despite the challenges arising from the pandemic and concerns that pre-service teachers would not be ready and prepared for a career in the classroom
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