893 research outputs found

    Interferon γ (IFN-γ) Is Necessary for the Genesis of Acetylcholine Receptor–induced Clinical Experimental Autoimmune Myasthenia gravis in Mice

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    Experimental autoimmune myasthenia gravis (EAMG) is an animal model of human myasthenia gravis (MG). In mice, EAMG is induced by immunization with Torpedo californica acetylcholine receptor (AChR) in complete Freund's adjuvant (CFA). However, the role of cytokines in the pathogenesis of EAMG is not clear. Because EAMG is an antibody-mediated disease, it is of the prevailing notion that Th2 but not Th1 cytokines play a role in the pathogenesis of this disease. To test the hypothesis that the Th1 cytokine, interferon (IFN)-γ, plays a role in the development of EAMG, we immunized IFN-γ knockout (IFN-gko) (−/−) mice and wild-type (WT) (+/+) mice of H-2b haplotype with AChR in CFA. We observed that AChR-primed lymph node cells from IFN-gko mice proliferated normally to AChR and to its dominant pathogenic α146–162 sequence when compared with these cells from the WT mice. However, the IFN-gko mice had no signs of muscle weakness and remained resistant to clinical EAMG at a time when the WT mice exhibited severe muscle weakness and some died. The resistance of IFN-gko mice was associated with greatly reduced levels of circulating anti-AChR antibody levels compared with those in the WT mice. Comparatively, immune sera from IFN-gko mice showed a dramatic reduction in mouse AChR-specific IgG1 and IgG2a antibodies. However, keyhole limpet hemocyanin (KLH)–priming of IFN-gko mice readily elicited both T cell and antibody responses, suggesting that IFN-γ regulates the humoral immune response distinctly to self (AChR) versus foreign (KLH) antigens. We conclude that IFN-γ is required for the generation of a pathogenic anti-AChR humoral immune response and for conferring susceptibility of mice to clinical EAMG

    Cutting-edge Innovations in Cardiac Health: Galvanic Insights from a Clinician-Scientist, Dr. Benjamin Hibbert

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    Dr. Benjamin Hibbert, MD, PhD, FRCPC is an interventional cardiologist, an assistant professor, as well as the director of the Vascular Biology and Experimental Medicine Laboratory at the University of Ottawa Heart Institute (UOHI). With a focus on performing revolutionary bench-to-bedside  research, Dr. Hibbert’s clinical and basic science research interests include the development of novel cardiac biomarkers, elucidating the mechanisms that underlie pathological arterial remodelling in transplant vasculopathy, and the pharmacodynamics of adjuvant  antiplatelet and antithrombotic agents in cardiac disease. We had the privilege of speaking with Dr. Hibbert about his career path, research experiences, and perspectives on the importance of the clinician-investigator program in training the oncoming generation of clinician-scientists

    Likely Impact of the COVID-19 Pandemic on Newborn Hearing Screening and Follow-up Services in the United States in 2020

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    This perspective aims to highlight aspects of the Early Hearing Detection and Intervention (EHDI) newborn hearing screening and follow-up processes that were impacted by the COVID-19 pandemic and considers factors that likely impacted follow-up after newborn hearing screening among infants born in the United States during 2020. Efforts to minimize the potential impact of missed or delayed identification of hearing loss in infants and young children will also be discussed to help guide future program improvement activities

    Cytokine-associated drug toxicity in human hepatocytes is associated signaling network dysregulation

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    Refer to Web version on PubMed Central for supplementary material.Idiosyncratic drug hepatotoxicity is a major problem in pharmaceutical development due to poor prediction capability of standard preclinical toxicity assessments and limited knowledge of its underlying mechanisms. Findings in animal models have shown that adverse effects of numerous drugs with idiosyncratic hepatotoxicity in humans can be reproduced in the presence of coincident inflammatory cytokine signaling. Following these observations, we have recently developed an in vitro drug/inflammatory cytokine co-treatment approach that can reproduce clinical drug hepatotoxicity signatures—particularly for idiosyncratic drugs—in cultured primary human hepatocytes. These observations have suggested that drug-induced stresses may interact with cytokine signaling to induce hepatic cytotoxicity, but the hepatocyte signaling mechanisms governing these interactions are poorly understood. Here, we collect high-throughput phosphoprotein signaling and cytotoxicity measurements in cultured hepatocytes, from multiple human donors, treated with combinations of hepatotoxic drugs (e.g. trovafloxacin, clarithromycin) and cytokines (tumor necrosis factor-α, interferon-γ, interleukin-1α, and interleukin-6). We demonstrate, through orthogonal partial least-squares regression (OPLSR) modeling of these signal-response data, that drug/cytokine hepatic cytotoxicity is integratively controlled by four key signaling pathways: Akt, p70 S6 kinase, MEK–ERK, and p38–HSP27. This modeling predicted, and experimental studies confirmed, that the MEK–ERK and p38–HSP27 pathways contribute pro-death signaling influences in drug/cytokine hepatic cytotoxicity synergy. Further, our four-pathway OPLSR model produced successful prediction of drug/cytokine hepatic cytotoxicities across different human donors, even though signaling and cytotoxicity responses were both highly donor-specific. Our findings highlight the critical role of kinase signaling in drug/cytokine hepatic cytotoxicity synergies and reveal that hepatic cytotoxicity responses are governed by multi-pathway signaling network balance.Pfizer Inc.Institute for Collaborative BiotechnologiesMIT Center for Cell Decision ProcessesNational Institute of Mental Health (U.S.) (grant P50-GM68762)Massachusetts Institute of Technology. Biotechnology Process Engineering CenterMassachusetts Institute of Technology. Center for Environmental Health SciencesNational Institute of Mental Health (U.S.) (grant U19ES011399)Whitaker Foundatio

    Clinical practice guidelines on the evidenceâ based use of integrative therapies during and after breast cancer treatment

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    Answer questions and earn CME/CNEPatients with breast cancer commonly use complementary and integrative therapies as supportive care during cancer treatment and to manage treatmentâ related side effects. However, evidence supporting the use of such therapies in the oncology setting is limited. This report provides updated clinical practice guidelines from the Society for Integrative Oncology on the use of integrative therapies for specific clinical indications during and after breast cancer treatment, including anxiety/stress, depression/mood disorders, fatigue, quality of life/physical functioning, chemotherapyâ induced nausea and vomiting, lymphedema, chemotherapyâ induced peripheral neuropathy, pain, and sleep disturbance. Clinical practice guidelines are based on a systematic literature review from 1990 through 2015. Music therapy, meditation, stress management, and yoga are recommended for anxiety/stress reduction. Meditation, relaxation, yoga, massage, and music therapy are recommended for depression/mood disorders. Meditation and yoga are recommended to improve quality of life. Acupressure and acupuncture are recommended for reducing chemotherapyâ induced nausea and vomiting. Acetylâ Lâ carnitine is not recommended to prevent chemotherapyâ induced peripheral neuropathy due to a possibility of harm. No strong evidence supports the use of ingested dietary supplements to manage breast cancer treatmentâ related side effects. In summary, there is a growing body of evidence supporting the use of integrative therapies, especially mindâ body therapies, as effective supportive care strategies during breast cancer treatment. Many integrative practices, however, remain understudied, with insufficient evidence to be definitively recommended or avoided. CA Cancer J Clin 2017;67:194â 232. © 2017 American Cancer Society.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136746/1/caac21397_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136746/2/caac21397.pd

    Synergistic drug-cytokine induction of hepatocellular death as an in vitro approach for the study of inflammation-associated idiosyncratic drug hepatotoxicity

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    Idiosyncratic drug hepatotoxicity represents a major problem in drug development due to inadequacy of current preclinical screening assays, but recently established rodent models utilizing bacterial LPS co-administration to induce an inflammatory background have successfully reproduced idiosyncratic hepatotoxicity signatures for certain drugs. However, the low-throughput nature of these models renders them problematic for employment as preclinical screening assays. Here, we present an analogous, but high-throughput, in vitro approach in which drugs are administered to a variety of cell types (primary human and rat hepatocytes and the human HepG2 cell line) across a landscape of inflammatory contexts containing LPS and cytokines TNF, IFNγ, IL-1α, and IL-6. Using this assay, we observed drug–cytokine hepatotoxicity synergies for multiple idiosyncratic hepatotoxicants (ranitidine, trovafloxacin, nefazodone, nimesulide, clarithromycin, and telithromycin) but not for their corresponding non-toxic control compounds (famotidine, levofloxacin, buspirone, and aspirin). A larger compendium of drug–cytokine mix hepatotoxicity data demonstrated that hepatotoxicity synergies were largely potentiated by TNF, IL-1α, and LPS within the context of multi-cytokine mixes. Then, we screened 90 drugs for cytokine synergy in human hepatocytes and found that a significantly larger fraction of the idiosyncratic hepatotoxicants (19%) synergized with a single cytokine mix than did the non-hepatotoxic drugs (3%). Finally, we used an information theoretic approach to ascertain especially informative subsets of cytokine treatments for most highly effective construction of regression models for drug- and cytokine mix-induced hepatotoxicities across these cell systems. Our results suggest that this drug–cytokine co-treatment approach could provide a useful preclinical tool for investigating inflammation-associated idiosyncratic drug hepatotoxicity.Pfizer Inc.Institute for Collaborative BiotechnologiesMIT Center for Cell Decision ProcessesNational Institute of Mental Health (U.S.) (grant P50-GM68762)National Institute of Mental Health (U.S.) (grant T32-GM008334)Massachusetts Institute of Technology. Biotechnology Process Engineering CenterMassachusetts Institute of Technology. Center for Environmental Health SciencesNational Institute of Mental Health (U.S.) (grant U19ES011399)Whitaker Foundatio

    Mapping multicenter randomized controlled trials in anesthesiology: a scoping review

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    Background: Evidence suggests that there are substantial inconsistencies in the practice of anesthesia. There has not yet been a comprehensive summary of the anesthesia literature that can guide future knowledge translation interventions to move evidence into practice. As the first step toward identifying the most promising interventions for systematic implementation in anesthesia practice, this scoping review of multicentre RCTs aimed to explore and map the existing literature investigating perioperative anesthesia-related interventions and clinical patient outcomes. Methods: Multicenter randomized controlled trials were eligible for inclusion if they involved a tested anesthesia-related intervention administered to adult surgical patients (≥ 16 years old), with a control group receiving either another anesthesia intervention or no intervention at all. The electronic databases Embase (via OVID), MEDLINE, and MEDLINE in Process (via OVID), and Cochrane Central Register of Control Trials (CENTRAL) were searched from inception to February 26, 2021. Studies were screened and data were extracted by pairs of independent reviewers in duplicate with disagreements resolved through consensus or a third reviewer. Data were summarized narratively. Results: We included 638 multicentre randomized controlled trials (n patients = 615,907) that met the eligibility criteria. The most commonly identified anesthesia-related intervention theme across all studies was pharmacotherapy (n studies = 361 [56.6%]; n patients = 244,610 [39.7%]), followed by anesthetic technique (n studies = 80 [12.5%], n patients = 48,455 [7.9%]). Interventions were most often implemented intraoperatively (n studies = 233 [36.5%]; n patients = 175,974 [28.6%]). Studies typically involved multiple types of surgeries (n studies = 187 [29.2%]; n patients = 206 667 [33.5%]), followed by general surgery only (n studies = 115 [18.1%]; n patients = 201,028 [32.6%]) and orthopedic surgery only (n studies = 94 [14.7%]; n patients = 34,575 [5.6%]). Functional status was the most commonly investigated outcome (n studies = 272), followed by patient experience (n studies = 168), and mortality (n studies = 153). Conclusions: This scoping review provides a map of multicenter RCTs in anesthesia which can be used to optimize future research endeavors in the field. Specifically, we have identified key knowledge gaps in anesthesia that require further systematic assessment, as well as areas where additional research would likely not add value. These findings provide the foundation for streamlining knowledge translation in anesthesia in order to reduce practice variation and enhance patient outcomes

    A DNMT3B Alternatively Spliced Exon and Encoded Peptide Are Novel Biomarkers of Human Pluripotent Stem Cells

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    A major obstacle in human stem cell research is the limited number of reagents capable of distinguishing pluripotent stem cells from partially differentiated or incompletely reprogrammed derivatives. Although human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) express numerous alternatively spliced transcripts, little attention has been directed at developing splice variant-encoded protein isoforms as reagents for stem cell research. In this study, several genes encoding proteins involved in important signaling pathways were screened to detect alternatively spliced transcripts that exhibited differential expression in pluripotent stem cells (PSCs) relative to spontaneously differentiated cells (SDCs). Transcripts containing the alternatively spliced exon 10 of the de novo DNA methyltransferase gene, DNMT3B, were identified that are expressed in PSCs. To demonstrate the utility and superiority of splice variant specific reagents for stem cell research, a peptide encoded by DNMT3B exon 10 was used to generate an antibody, SG1. The SG1 antibody detects a single DNMT3B protein isoform that is expressed only in PSCs but not in SDCs. The SG1 antibody is also demonstrably superior to other antibodies at distinguishing PSCs from SDCs in mixed cultures containing both pluripotent stem cells and partially differentiated derivatives. The tightly controlled down regulation of DNMT3B exon 10 containing transcripts (and exon 10 encoded peptide) upon spontaneous differentiation of PSCs suggests that this DNMT3B splice isoform is characteristic of the pluripotent state. Alternatively spliced exons, and the proteins they encode, represent a vast untapped reservoir of novel biomarkers that can be used to develop superior reagents for stem cell research and to gain further insight into mechanisms controlling stem cell pluripotency

    The Complete Chloroplast and Mitochondrial Genome Sequences of Boea hygrometrica: Insights into the Evolution of Plant Organellar Genomes

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    The complete nucleotide sequences of the chloroplast (cp) and mitochondrial (mt) genomes of resurrection plant Boea hygrometrica (Bh, Gesneriaceae) have been determined with the lengths of 153,493 bp and 510,519 bp, respectively. The smaller chloroplast genome contains more genes (147) with a 72% coding sequence, and the larger mitochondrial genome have less genes (65) with a coding faction of 12%. Similar to other seed plants, the Bh cp genome has a typical quadripartite organization with a conserved gene in each region. The Bh mt genome has three recombinant sequence repeats of 222 bp, 843 bp, and 1474 bp in length, which divide the genome into a single master circle (MC) and four isomeric molecules. Compared to other angiosperms, one remarkable feature of the Bh mt genome is the frequent transfer of genetic material from the cp genome during recent Bh evolution. We also analyzed organellar genome evolution in general regarding genome features as well as compositional dynamics of sequence and gene structure/organization, providing clues for the understanding of the evolution of organellar genomes in plants. The cp-derived sequences including tRNAs found in angiosperm mt genomes support the conclusion that frequent gene transfer events may have begun early in the land plant lineage
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