RESUMO
Circular RNAs (circRNAs) are a new class of covalently circularized noncoding RNAs widely expressed in the human heart. Emerging evidence suggests they have a regulatory role in a variety of cardiovascular diseases (CVDs). This review's current focus includes our understanding of circRNA classification, biogenesis, function, stability, degradation mechanisms, and their roles in various cardiovascular disease conditions. Our knowledge of circRNA, the relatively recent member of the noncoding RNA family, is still in its infancy; however, recent literature proposes circRNAs may be promising targets for the understanding and treatment of CVD.
Assuntos
Doenças Cardiovasculares/genética , RNA Circular , Animais , Humanos , RNA Circular/metabolismoRESUMO
Chitin, a homopolymer of ß1,4-linked N-acetylglucosamine (GlcNAc) residues, is a key component of the cell walls of fungi and the exoskeletons of arthropods. Chitin synthases transfer GlcNAc from UDP-GlcNAc to preexisting chitin chains in reactions that are typically stimulated by free GlcNAc. The effect of GlcNAc was probed by using a yeast strain expressing a single chitin synthase, Chs2, by examining formation of chitin oligosaccharides (COs) and insoluble chitin, and by replacing GlcNAc with 2-acylamido analogues of GlcNAc. Synthesis of COs was strongly dependent on inclusion of GlcNAc in chitin synthase incubations, and N,N'-diacetylchitobiose (GlcNAc2) was the major reaction product. Formation of both COs and insoluble chitin was also stimulated by GlcNAc2 and by N-propanoyl-, N-butanoyl-, and N-glycolylglucosamine. MALDI analyses of the COs made in the presence of 2-acylamido analogues of GlcNAc showed they that contained a single GlcNAc analogue and one or more additional GlcNAc residues. These results indicate that Chs2 can use certain 2-acylamido analogues of GlcNAc, and likely free GlcNAc and GlcNAc2 as well, as GlcNAc acceptors in a UDP-GlcNAc-dependent glycosyltransfer reaction. Further, formation of modified disaccharides indicates that CSs can transfer single GlcNAc residues.
Assuntos
Acetilglucosamina/metabolismo , Quitina Sintase/metabolismo , Quitina/biossíntese , Oligossacarídeos/biossíntese , Proteínas de Saccharomyces cerevisiae/metabolismo , Acetilglucosamina/química , Acetilglucosamina/farmacologia , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Quitina/química , Quitina Sintase/genética , Dissacarídeos/química , Dissacarídeos/metabolismo , Relação Dose-Resposta a Droga , Glucose/farmacologia , Mutação , Oligossacarídeos/química , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Inorganic polyphosphates, linear polymers of orthophosphate, occur naturally throughout biology and have many industrial applications. Their biodegradable nature makes them attractive for a multitude of uses, and it would be important to understand how polyphosphates are turned over enzymatically. Studies of inorganic polyphosphatases are, however, hampered by the lack of high-throughput methods for detecting and quantifying rates of polyphosphate degradation. We now report chromogenic and fluorogenic polyphosphate substrates that permit spectrophotometric monitoring of polyphosphate hydrolysis and allow for high-throughput analyses of both endopolyphosphatase and exopolyphosphatase activities, depending on assay configuration. These substrates contain 4-nitrophenol or 4-methylumbelliferone moieties that are covalently attached to the terminal phosphates of polyphosphate via phosphoester linkages formed during reactions mediated by EDAC (1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide). This report identifies Nudt2 as an inorganic polyphosphatase and also adds to the known coupling chemistry for polyphosphates, permitting facile covalent linkage of alcohols with the terminal phosphates of inorganic polyphosphate.
Assuntos
Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Polifosfatos/química , Hidrolases Anidrido Ácido/metabolismo , Fosfatase Alcalina/metabolismo , Digestão , Hidrólise , Nitrofenóis/químicaRESUMO
BACKGROUND: Academic emergency medicine (EM) is foundational to the EM specialty through the development of new knowledge and clinical training of resident physicians. Despite recent increased attention to the future of the EM workforce, no evaluations have specifically characterized the U.S. academic EM workforce. We sought to estimate the national proportion of emergency physicians (EPs) identified as academic and the proportion of emergency department (ED) visits that take place at academic sites. METHODS: We performed a cross-sectional analysis of EPs and EDs using data from the American Hospital Association, the Centers for Medicare & Medicaid Services, and Doximity's Residency Navigator. EPs were identified as "academic" if they were affiliated with at least one facility determined to be academic, defined as EDs officially designated by the Accreditation Council for Graduate Medical Education (ACGME) as clinical training sites at accredited EM residency programs. Our primary outcomes were to estimate the national proportion of EPs identified as academic and the proportion of ED visits performed at academic sites. RESULTS: Our analytic sample included 26,937 EPs practicing clinically across 4920 EDs and providing care during 130,471,386 ED visits. Among EPs, 11,720 (43.5%) were identified as academic, and among EDs, 635 (12.9%) were identified as academic sites, including 585 adult/general sites, 45 pediatric-specific sites, and 10 sites affiliated with the Department of Veterans Affairs. In 2021, academic EDs provided care for 42,794,106 ED visits or 32.8% of all ED visits nationally. CONCLUSIONS: Approximately four in 10 EPs practice in at least one clinical training site affiliated with an ACGME-accredited EM residency program, and approximately one in three ED visits nationally occur in these academic EDs. We encourage further work using alternative definitions of an academic EPs and EDs, along with longitudinal research to identify trends in the workforce's composition.
Assuntos
Medicina de Emergência , Serviço Hospitalar de Emergência , Médicos , Humanos , Estudos Transversais , Estados Unidos , Medicina de Emergência/educação , Serviço Hospitalar de Emergência/estatística & dados numéricos , Médicos/provisão & distribuição , Médicos/estatística & dados numéricos , Centros Médicos Acadêmicos/estatística & dados numéricos , Recursos Humanos/estatística & dados numéricos , Internato e Residência/estatística & dados numéricosRESUMO
The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was declared a pandemic by the WHO in March 2020. As of August 2021, more than 220 countries have been affected, accounting for 211,844,613 confirmed cases and 4,432,802 deaths worldwide. A new delta variant wave is sweeping through the globe. While previous reports consistently have demonstrated worse prognoses for patients with existing cardiovascular disease than for those without, new studies are showing a possible link between SARS-CoV-2 infection and an increased incidence of new-onset heart disease and diabetes, regardless of disease severity. If this trend is true, with hundreds of millions infected, the disease burden could portend a potentially troubling increase in heart disease and diabetes in the future. Focusing on heart failure in this review, we discuss the current data at the intersection of COVID, heart failure, and diabetes, from clinical findings to potential mechanisms of how SARS-CoV-2 infection could increase the incidence of those pathologies. Additionally, we posit questions for future research areas regarding the significance for patient care.
RESUMO
Anti-programmed death 1 (PD-1) immune checkpoint inhibitors enhance the antitumour activity of the immune system and have produced durable tumour responses in several solid tumours including non-small cell lung cancer (NSCLC). However, PD-1 inhibitors can lead to immune-related adverse events , including pneumonitis, which is typically mild, but can be severe and potentially fatal. Pneumonitis often resolves with steroids, but some cases are steroid refractory, leading to a relapsing and remitting course in milder cases or the need for salvage therapies in more severe cases. Here, we present two patients with NSCLC who developed severe pneumonitis following therapy with nivolumab and pembrolizumab. While one patient improved with steroids and infliximab, the other patient failed to respond to steroids and subsequently died. These cases demonstrate the highly variable presentation and therapeutic responses seen in patients with pneumonitis following anti-PD-1 therapy and illustrate that severe cases can often present refractory to steroid therapy.