Exogenous reactive oxygen and nitric oxide alter intracellular oxidant status of skeletal muscle fibres

To test whether exogenous oxidants alter intracellular oxidant levels in skeletal muscle fibres, we exposed rat diaphragm to donors of nitric oxide (NO_x), reactive oxygen species (ROS) or hyperoxia, and monitored intracellular oxidant levels using a fluorescent probe. Fibre bundles were dissected from the diaphragm and loaded with 2’,7’-dichlorodihydrofluorescein (DCFH); emissions were monitored using a fluorescence microscope. DCFH-loaded muscles were exposed to either a NO_x donor (1 m M S-nitroso-N-acetyl penicillamine, SNAP; 1 m M sodium nitroprusside, SNP; 400 μM 1-hydroxy-2-oxo-3-(N-3-methyl-aminopropyl)-3-methyl-1-triazen, NOC-7), an ROS donor (100 μM hydrogen peroxide, H₂O₂; 100 μM tert-butyl hydroperoxide; 1 m M hypoxanthine plus 0.01 U mL^–1 xanthine oxidase, HXXO) or a range of PO ₂s (25, 60 or 95% O₂ oxygenating Krebs–Ringer solution) for 40 min; time-matched control bundles remained in Krebs–Ringer solution. Control muscles oxidized DCFH at a rate of 0.32 ± 0.1 greyscale units min^–1. SNAP (766%), SNP (1244%), NOC-7 (851%), H₂O₂ (543%), and HXXO (541%) increased DCFH oxidation from control levels. The increase in emissions caused by NOC-7 and SNP were blunted by the NO_x scavenger haemoglobin (1 μM ). DCFH oxidation by HXXO was unaffected by 1000 U mL^–1 superoxide dismutase but was significantly decreased by 1000 U mL^–1 catalase and 1 m M salicylate. PO ₂ had no effect on intracellular oxidant levels. Therefore, extracellular NO_x and ROS can alter intracellular oxidant status in skeletal muscle fibres. These observations suggest that intrafibre oxidant levels could be the result of both intracellular and extracellular oxidant production.     

Evidence for glial-mediated inflammation in aged APPSW transgenic mice

Chronic expression of inflammatory cytokines, including interleukin-1β, tumor necrosis factor α, and interleukin-6, by glia may underlie the neurodegenerative events that occur within the brains of patients with Alzheimer’s disease (AD). The present study determined whether these markers of inflammation could be observed within the brains of Tg(HuAPP695.K670N/M671L)2576 transgenic mice (Tg2576) that have recently been shown to mimic many features of AD. Interleukin-1β- and tumor necrosis factor α-immunopositive microglia were localized with thioflavine-positive (fibrillar) Aβ deposits. Moreover, interleukin-6 immunoreactive astrocytes surrounded fibrillar Aβ deposits. These findings provide evidence that Tg2576 mice exhibit features of the inflammatory pathology seen in AD and suggest that these mice are a useful animal model for studying the role inflammation may play in this disease.     

儿童和青少年新型冠状病毒感染的研究进展

随着成年人大规模接种新型冠状病毒(新冠病毒)疫苗, 儿童和青少年群体由于较低疫苗覆盖率和较高接触度, 逐渐成为新冠病毒感染的脆弱人群, 有必要总结儿童和青少年群体新冠病毒感染特征、新冠病毒疫苗对于变异株的免疫效果。本文检索现有文献, 对儿童和青少年新冠病毒感染的研究进展进行综述, 分析儿童和青少年对于新冠病毒的易感性、感染者的传播力和疾病预后以及免疫应答和新冠病毒疫苗的进展等关键特征, 为新冠病毒肺炎疫情防控提供参考依据。     

The effect of glucocorticoids on mortality in severe COVID-19 patients: Evidence from 13 studies involving 6612 cases

Background:Since the start of the coronavirus disease 2019 (COVID-19) pandemic, there is an urgent need for effective therapies for patients with COVID-19. In this study, we aimed to assess the therapeutic efficacy of glucocorticoids in severe COVID-19.Methods:A systematic literature search was performed across PubMed, Web of Science, EMBASE, and the Cochrane Library (up to June 26, 2021). The literature investigated the outcomes of interest were mortality and invasive mechanical ventilation.Results:The search identified 13 studies with 6612 confirmed severe COVID-19 patients. Our meta-analysis found that using glucocorticoids could significantly decrease COVID-19 mortality (hazard ratio (HR) 0.60, 95% confidence interval (CI) 0.45–0.79, P < .001), relative to non-use of glucocorticoids. Meanwhile, using glucocorticoids also could significantly decrease the risk of progression to invasive mechanical ventilation for severe COVID-19 patients (HR = 0.69, 95% CI 0.58–0.83, P < .001). Compared with using dexamethasone (HR = 0.68, 95% CI 0.50–0.92, P = .012), methylprednisolone use had a better therapeutic effect for reducing the mortality of patients (HR = 0.35, 95% CI 0.19–0.64, P = .001).Conclusion:The result of this meta-analysis showed that using glucocorticoids could reduce mortality and risk of progression to invasive mechanical ventilation in severe COVID-19 patients.     

广东省新型冠状病毒肺炎确诊病例出院后复检病毒核酸阳性特征及影响因素分析

目的:分析广东省2020年初国内输入疫情阶段新型冠状病毒肺炎（新冠肺炎）确诊病例出院后复检新型冠状病毒核酸阳性（复检阳性）特征及影响因素。方法:收集广东省新冠肺炎确诊病例（发病时间在2020年3月1日以前）的人口学资料、流行病学调查及出院后标本采集与检测等信息。采用logistic回归模型分析确诊病例复检阳性的影响因素...     

新冠病毒奥密克戎变异株的特点与防控措施

 自2021年11月新型冠状病毒奥密克戎变异株出现以来,几个月内迅速席卷全球。世界各国都出现了以奥密克戎为主要流行毒株的新一轮疫情,我国香港、深圳、上海等城市也未能幸免。奥密克戎刺突蛋白含有大量突变,具有强大的免疫逃逸能力,对现有的疫苗和抗体相关治疗造成了巨大的威胁。虽然奥密克戎变异株引起的疾病症状较轻,但由于其超高的传播率,全球卫生系统均承受了巨大的压力。本文就奥密克戎变异株的病原学特征、变异来源、传播特征、流行现状及防治措施等方面进行综述,以期为科学防控提供参考。     

The first presentation of Wolcott‐Rallison syndrome in a four‐month‐old infant with diabetic ketoacidosis (DKA) precipitating by COVID‐19: A case report

Monogenic diabetes mellitus (eg, Wolcott‐Rallison syndrome) is a rare condition. It associates with neonatal or early‐infancy insulin‐dependent diabetes. We reported DKA in the four‐month infant as the first presentation of monogenic diabetes that has accelerated by COVID‐19 infection. Therefore, considering the concurrency of COVID‐19 and DKA is crucial.