白藜芦醇联合顺铂对神经胶质瘤细胞的作用*

目的： 探讨白藜芦醇联合顺铂对神经胶质瘤细胞C6 的作用。方法：不同浓度的白藜芦醇与顺铂单独联合 作用于神经胶质瘤细胞C6，24、48 h 和72 h 后，CCK8法检测增殖，并选出合适浓度进行后续试验；不同浓度的 药物作用于细胞24 h 后，吖啶橙法观察细胞形态变化、流式细胞仪检测细胞凋亡、细胞周期和免疫印迹检测蛋白 Bax、Bcl-2 和p-Erk1/2 变化。结果：白藜芦醇与顺铂能协同抑制神经胶质瘤细胞C6 的增殖。联合用药后细胞周 期抑制在S 期。免疫印迹结果显示凋亡蛋白Bax 的表达量增加，而凋亡抑制蛋白Bcl-2 的表达量减少，细胞外调 节蛋白激酶p-Erk1/2 的表达量减少。结论：白藜芦醇与顺铂联合对神经胶质瘤细胞具有相互增敏作用，能够协同 抑制细胞增殖，并通过Ras-Raf-MEK-Erk 信号通路促进其凋亡。     

负荷渐增式训练对老年小鼠骨骼肌卫星细胞AMPK磷酸化的影响

目的 探讨负荷渐增式训练对老年小鼠骨骼肌卫星细胞腺苷酸活化蛋白激酶（AMP-activated protein kinase，AMPK）磷酸化的影响。方法 实验小鼠分为 3 组：青年对照组（YC组，n=12）、老年对照组（OC组，n=12）与老年运动组（OT组，n=12）。OT组进行负荷渐增式训练，流式细胞分选技术分离CD45-/CD31-/Sca1-/VCAM(CD106)+细胞群体，分选细胞通过desmin、Myod肌原性染色以及成肌分化诱导培养进行肌卫星细胞鉴定，免疫组化结合Western blotting方法检测肌卫星细胞p-AMPK水平。结果 YC组骨骼肌卫星细胞AMPK及p-AMPK表达水平显著高于OC组（P<0.05）；OT组与OC组AMPK表达无明显变化（Ｐ>0.05），而OT组p-AMPK表达水平显著高于OC组（P<0.05）。结论 负荷渐增式训练可促进老年小鼠骨骼肌卫星细胞AMPK磷酸化，改善老年小鼠骨骼肌能量代谢。     

Clearing hepatitis C virus with direct antiviral agents reduces cardiovascular events in patients with prediabetes. Commentary to Sasso and colleagues

Liver health is a key determinant of cardiovascular risk (CVR). Hepatic fibrosis is the shared common result of chronic hepatitis, irrespective of aetiology. Fibrosis profoundly distorts liver tissue architecture and perturbs hepatic physiology, dictates the course of chronic liver disease and is increasingly recognized as a CVR factor. The relative weights of pre-diabetes and hepatic fibrosis as risk factors for major adverse cardiac events (MACE) in patients with HCV remain an open issue. Sasso and Colleagues answered this research question by treating approximately half of 770 HCV positive pre-diabetic patients with direct antiviral agents (DAAs), while the rest served as historical controls. Data have shown that achieving HCV clearance with DAAs was associated with a 60% reduced risk of MACE, thereby implying that this antiviral strategy is recommended in HCV positive pre-diabetic patients, regardless of the severity of liver disease and concurrent CVR factors. This study paves the way for additional studies addressing the molecular patho-mechanisms and changes in the clinical spectrum involved in cardio-metabolic protection following HCV eradication in patients with pre-diabetes.     

CYP2C19*2、CYP2C19*3基因分型与急性缺血性脑卒中再发脑卒中的关系

目的探讨细胞色素P450药物代谢酶(CYP)2C19基因分型与氯吡格雷治疗的急性缺血性脑卒中患者再发脑卒中的关系。方法选取2018年5月—2018年12月常州市第一人民医院收治接受氯吡格雷治疗的159例急性缺血性脑卒中患者,检测患者入院后空腹外周血中CYP2C19*2,CYP2C19*3基因分型。对患者进行随访,随访截至2020年2月,观察再发脑卒中的情况,并分析CYP2C19*2,CYP2C19*3基因分型与再发脑卒中关系。结果随访时间14~22个月,平均随访时间为(18.2±1.5)个月,共7例患者失访,共20例(13.2%)患者复发缺血性脑卒中。再发脑卒中患者中CYP2C19*2 GG型及CYP2C19*3 GG型均低于无复发患者(P<0.05),CYP2C19*2 GA型,CYP2C19*2 AA型CYP2C19*3 GA型,CYP2C19*3AA型均高于无复发患者(P<0.05)。Kaplan-Meier法并Log-rank检验结果显示,CYP2C19*2 GG型无复发时间长于AA型,差异有统计学意义(Log-rank=6.759,P=0.034)。CYP2C19*3GG型无复发时间长于AA型,差异有统计学意义(Log-rank x2=8.660,P=0.013)。多因素Cox分析结果显示,糖尿病、氯吡格雷抵抗,CYP2C19*2及CYP2C19*3基因型是再发脑卒中影响因素(P<0.05)。结论在接受氯吡格雷治疗急性缺血性脑卒中患者中,CYP2C19*2及CYP2C19*3突变型再发脑卒中的风险明显增高。     

Cholinergic hyperactivity in patients with myasthenia gravis with MuSK antibodies: A neurophysiological study

ObjectivePatients with myasthenia gravis associated with muscle-specific tyrosine kinase antibodies (MuSK-MG) often manifest signs of cholinergic hyperactivity with standard doses of acetylcholinesterase inhibitors (AChE-Is). Aim of the study was to investigate whether repetitive compound muscle action potential (R-CMAP), the neurophysiological correlate of cholinergic hyperactivity, was present in MuSK-MG irrespective of AChE-I treatment.MethodsPatients with confirmed diagnosis of MuSK-MG were consecutively enrolled during follow-up visits, from January 2019 to April 2020. All these subjects underwent the same neurophysiological protocol, including motor nerve conduction studies and repetitive nerve stimulation. In patients taking pyridostigmine, neurophysiological testing was performed at least 12 hours after the last dose. For comparison, the presence of R-CMAP was investigated in 20 consecutive acetylcholine receptor antibody positive myasthenia gravis (AChR-MG) patients.ResultsWe enrolled 25 MuSK-MG patients (20 females), aged 16–79 years at the study time, with disease duration ranging 0.6–48.8 years (median: 17.7 years). R-CMAP was detected in 12/25 (48%) MuSK-MG cases and in none of the AChR-MG controls (p = 0.0003). In the MuSK-MG population, a history of muscle cramps and fasciculations, during low-dose pyridostigmine therapy, was significantly more frequent in R-CMAP positive than in R-CMAP negative patients (100% vs 31%, p = 0.001). At the time of the study, the proportion of patients still symptomatic for MG was higher among R-CMAP positive cases (92% vs 23%, p = 0.0005).ConclusionsCholinergic hyperactivity is a relatively common finding in MuSK-MG patients, independent of AChE-I treatment, and may constitute an intrinsic feature of the disease.SignificanceR-CMAP detection can represent a useful diagnostic clue for MuSK-MG and predicts poor tolerance to AChE-Is.     

Will Mutations in the Spike Protein of SARS-CoV-2 Lead to the Failure of COVID-19 Vaccines?

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), which has spread worldwide since it was first identified in Wuhan, China, at the end of 2019. With the global transmission of the virus, a large number of SARS-CoV-2 variants have also appeared, especially, emerging strains that have recently been discovered in the United Kingdom (variant 20I/501Y.V1, lineage B.1.1.7), South Africa (variant 20H/501Y.V2, lineage B.1.351), and Brazil (variant 20 J/501Y.V3, and lineage P.1). The common feature of these variants is that they share the N501Y mutation involving the SARS-CoV-2 spike (S) protein, which is precisely the target of most COVID-19 vaccines. Furthermore, mutations such as N501Y, E484K, and K417N in the S protein may affect viral fitness and transmissibility. However, current research on the impact of these variants on COVID-19 vaccines is still lacking. Herein, we briefly explain why most COVID-19 vaccines target the S protein, update the progress of research regarding S protein-related COVID-19 vaccines, review the latest studies concerning the effects of S protein variants on COVID-19 vaccines, and finally, propose certain strategies to deal with SARS-CoV-2 variants.