HIV-1 黑龙江省分离株CHNHLJ03009包膜克隆及分析

目的 分析黑龙江省Ⅰ型人免疫缺陷病毒（human irnmunodeficiency virus type 1，HIV-1）原代分离株包膜糖蛋白的变异性及表型特征。方法从一名HIV阳性但未发病的感染者外周血单个核细胞提取DNA，采用保守引物进行HIV包膜直接克隆，进行序列分析及系统树分析。构建了一株带该包膜蛋白的伪病毒并利用表达CXCR4和CCR5的靶细胞进行了感染实验，观察该病毒包膜利用辅助受体的表型特征。结果共获得2个有功能全长env克隆，分别命名为CHNHIJ03009c34（GenBank序列号为AY905493）和CHNHIA03009c33。用全长env氨基酸序列与国内外分离株进行同源性比较分析发现，与分离株CHNHLJ03009c34的包膜同源性最高的病毒为云南的HIV-1 B’亚型分离株RIA2，同源性为91．52％。系统发育分析结果表明，该株为泰国B’亚型，与云南分离株RIA2的遗传距离最近。对包膜蛋白结构分析结果显示，分离株CHNHLJ03009c34包膜在抗原性和亲水性上与RIA2没有明显差别。感染性检测结果显示该病毒只能感染U87．CD4．CCR5细胞，不能感染U87．CD4．CX-CR4细胞。结论本研究从黑龙江省一名HIV-1阳性者克隆到HIV-1CHNHLJ03009病毒的包膜基因，该病毒属于B’亚型（泰国亚型），为R5亲嗜性毒株。该包膜基因克隆为首次报道的黑龙江分离株。     

贵州白纹伊蚊对登革病毒易感性的研究

目的 用细胞、分子生物学技术进行贵州省白纹伊蚊不同地理株对登革病毒(DEN)易感性的研究。方法 采集贵州省9个地(州)市共计15个县(区)白纹伊蚊幼虫标本，饲养为成蚊；取羽化后3～5日龄期的贵州不同地理株白纹伊蚊，用不同型别的DEN分别经口连续感染3d，于首次感染后的4、7、10、14d收集感染成蚊标本；制备蚊悬液，碘化钠法提取RNA，用DENNS1基因区通用引物经逆转录．聚合酶链反应(RT-PCR)检测DEN核酸；蚊悬液接种C6／36细胞进行病毒分离，制作细胞抗原片，经间接免疫荧光法检测DEN抗原；同时感染白纹伊蚊海南株作为对照。结果 DEN1-4型国际参考株感染白纹伊蚊贵州省不同地方株，其感染比率分别为12／15、12／15、8／15和13／15。结论 白纹伊蚊贵州省不同地方株对DEN1-4型国际参考株普遍易感，表明贵州省具备引起登革热流行的条件。     

丙型肝炎病毒阳性血清体外感染人肝细胞的研究

目的 研究丙型肝炎病毒(HCV)抗体(Ab)阴性,HCV-RNA阳性血清建立体外感染肝细胞模型.方法 HCV Ab阴性,HCV-RNA阳性的窗口期血清与人肝细胞共同培养,用反转录-聚合酶链反应(RT-PCR)、免疫荧光染色、Western blot、共聚焦显微镜和透射电镜等方法检测细胞内HCV核酸复制、蛋白质表达及超微结构改变.结果 细胞与病毒共同培养7～45 d,细胞内和/或培养上清中可间断检出HCV正、负链RNA;细胞浆内有HCV 核心和NS3抗原的表达;细胞超微结构有改变,并于感染后第24天时观察到类似病毒样颗粒.结论 窗口期血清中的HCV能在人肝细胞7701中复制一段时间.     

Development of retroviral vectors as safe, targeted gene delivery systems

The transfer of genes of potential therapeutic benefit is presently being attempted in the clinic to treat a number of genetic and virally induced diseases. Many of these protocols use retroviral vectors derived from murine leukemia retroviruses as gene delivery systems. Although these viral delivery systems are well suited for this purpose, a number of their characteristics, some of which are discussed here, are still troublesome. Future retroviral vectors will incorporate nonretroviral features and will be tailored to desired needs for specific uses. These vectors will be safer, more efficient, and targeted in their delivery. Further, expression of the therapeutic genes carried will be limited to the specific target cell type. Some of the recent advances that have been made towards this goal are reviewed here.     

Conformational changes in Sindbis virions resulting from exposure to low pH and interactions with cells suggest that cell penetration may occur at the cell surface in the absence of membrane fusion

Alphaviruses have the ability to induce cell-cell fusion after exposure to acid pH. This observation has served as an article of proof that these membrane-containing viruses infect cells by fusion of the virus membrane with a host cell membrane upon exposure to acid pH after incorporation into a cell endosome. We have investigated the requirements for the induction of virus-mediated, low pH-induced cell-cell fusion and cell-virus fusion. We have correlated the pH requirements for this process to structural changes they produce in the virus by electron cryo-microscopy. We found that exposure to acid pH was required to establish conditions for membrane fusion but that membrane fusion did not occur until return to neutral pH. Electron cryo-microscopy revealed dramatic changes in the structure of the virion as it was moved to acid pH and then returned to neutral pH. None of these treatments resulted in the disassembly of the virus protein icosahedral shell that is a requisite for the process of virus membrane-cell membrane fusion. The appearance of a prominent protruding structure upon exposure to acid pH and its disappearance upon return to neutral pH suggested that the production of a "pore"-like structure at the fivefold axis may facilitate cell penetration as has been proposed for polio (J. Virol. 74 (2000) 1342) and human rhino virus (Mol. Cell 10 (2002) 317). This transient structural change also provided an explanation for how membrane fusion occurs after return to neutral pH. Examination of virus-cell complexes at neutral pH supported the contention that infection occurs at the cell surface at neutral pH by the production of a virus structure that breaches the plasma membrane bilayer. These data suggest an alternative route of infection for Sindbis virus that occurs by a process that does not involve membrane fusion and does not require disassembly of the virus protein shell.     

Resolution of late-developing periprosthetic breast infections without prosthesis removal

Based on prior experience with implant exposure, an aggressive regimen to eradicate periprosthetic infections has proven successful in delayed gram-positive and gram-negative bacterial infections and in atypical microbacterial infections. The objective of the salvage procedure is to retain a prosthesis, to maintain breast contour, and to avoid psychological and physical consequences of prosthesis removal. The salvage procedure involves topical antisepsis, contracture release if needed, systemic and topical antibiotics with intermittent or continuous irrigation, and reinforcement of incision lines in selected cases using local tissue flaps.     

Association between chronic hepatitis C infection and metabolic syndrome: A meta-analysis

BackgroundHepatitis C virus (HCV) infected patients have been found to be more susceptible to metabolic syndrome (MetS), but the results remain unclear and lack of a meta-analysis.MethodsDatabases including PubMed, Web of Science, EMBASE and the Cochrane Library were searched to identify all studies concerning HCV and MetS. Funnel plots combined with Begg's tests and Egger's tests were used to analysis the possible publication bias. The odds ratios (ORs) with 95% confidence intervals (CIs) were used to access the effect of HCV infection on the risk of MetS.ResultsEight articles, involving a total of 57387 HCV patients were included. HCV infection was significantly associated with an increased incidence of MetS (OR = 1.73; 95% CI, 1.19–2.52). After adjustment according to the sensitivity analysis, one included article was removed to decrease the publication bias and high heterogeneity, of which the results showed that HCV infection was still associated with an increased incidence of MetS (OR = 1.93; 95% CI, 1.39–2.68).ConclusionsHCV patients tend to have a significant increased risk for MetS, but more large-scale studies are needed to confirm this and explore the exact mechanism.     

Infection Control Citations in Nursing Homes: Compliance and Geographic Variability

ObjectivesTo report the initial compliance with new infection control regulations and geographic disparities in nursing homes (NHs) in the United States.DesignRetrospective cohort study from November 27, 2017 to November 27, 2019.Setting and ParticipantsIn total, 14,894 NHs in the continental United States comprising 26,201 inspections and 176,841 deficiencies.MethodsWe measured the cumulative incidence of receiving F880: Infection Prevention and Control deficiencies, geographic variability of F880 citations across the United States, and the scope and severity of the infection control deficiencies.ResultsA total of 6164 NHs (41%) in the continental United States received 1 deficiency for F880, and 2300 NHs (15%) were cited more than once during the 2-year period. Geographic variation was evident for F880 deficiencies, ranging from 20% of NHs in North Carolina to 79% of NHs in West Virginia. Between 0% (Vermont) and 33% (Michigan) of states’ NHs were cited multiple times over 2 years. Facilities receiving 2 or more F880 deficiencies were more reliant on Medicaid, for-profit, and served more acute residents. Infection Prevention and Control deficiencies were of similar severity but of greater scope in NHs that were cited multiple times.Conclusions and ImplicationsAs the coronavirus disease 2019 pandemic challenges hospitals with an increased surge of patients from the community, NHs will be asked to accept convalescing patients who were previously infected with the virus. NHs will need to rely on infection control practices to mitigate the effects of the virus in their facilities. Particular attention to NHs that have fared poorly with repeat infection control practices deficiencies might be a good first step to improving care overall and preventing downstream morbidity and mortality among the highest-risk patients.     

阴道微环境失衡与高危型人乳头瘤病毒持续感染

目的探讨阴道微生态失衡与高危型人乳头瘤病毒(HR-HPV)持续感染的关系。 方法选择2014年1月至2015年12月,在四川省科学城医院妇科诊断为HR-HPV感染的240例患者为研究对象,年龄为19~73岁。根据HR-HPV感染状态,将其分为研究组(n＝121,HR-HPV持续感染者)和对照组(n＝119,HR-HPV复查呈阴性者)。采用成组t检验,对2组患者的体重、人体质量指数(BMI)、孕次、产次等进行统计学分析。采用χ²检验,对2组患者的细菌性阴道病(BV)、外阴阴道假丝酵母菌病(VVC)、滴虫性阴道炎(TV)、需氧菌性阴道炎(AV)发生率等进行统计学分析。本研究遵循的程序符合2013年修订的《世界医学协会赫尔辛基宣言》要求。 结果①2组受试者体重、BMI、孕次和产次等一般临床资料比较,差异均无统计学意义(P>0.05)。②研究组患者BV、VVC检出率分别为43.0%(52/121)、38.0%(46/121),明显高于对照组的20.2%(24/119)、15.1%(18/119),2组比较,差异均有统计学意义(χ²＝14.422、16.075,P＝0.002、<0.001)。研究组和对照组患者的TV、AV和混合性感染患者检出率比较,差异均无统计学意义(P>0.05)。 结论BV、VVC与HR-HPV持续性感染密切相关,改善阴道微生态环境可能有助于降低HR-HPV的发生率。     

根治性膀胱癌切除术后感染切口愈合的危险因素

目的探究根治性膀胱癌切除术后感染切口愈合的危险因素及与单核淋巴细胞因子的关系。方法回顾性选取2015年1月-2018年12月于南阳市中心医院泌尿外科接受根治性膀胱癌切除术治疗的患者作为研究对象,共200例,根据术后切口是否发生感染分为感染组(n=100)和未感染组(n=100),其中感染组根据切口愈合时间分为早期愈合组(n=65)和延迟愈合组(n=35)。对影响根治性膀胱癌切除术后感染切口愈合的因素进行单因素和多因素Logistic回归分析;比较感染组和未感染组血清单核淋巴细胞水平。结果延迟愈合组患者术中出血量高于早期愈合组,白蛋白含量低于早期愈合组,手术时间长于早期愈合组,尿瘘、肠瘘次数均高于早期愈合组(均P<0.05)。经Logistic回归分析,白蛋白、术中出血量、手术时间、尿瘘、肠瘘是影响患者感染切口愈合的独立危险因素(P<0.05)。切口感染组血清肿瘤坏死因子-α(TNF-α)、粒细胞集落刺激因子(G-CSF)、白细胞介素-8(IL-8)、IL-4、IL-6水平高于未感染组(均P<0.05),而IL-2水平低于未感染组(P<0.05)。结论白蛋白、术中出血量、手术时间、尿瘘、肠瘘是影响患者感染切口愈合的独立危险因素,在临床上应采取有针对性的预防控制措施,避免影响术后切口的愈合。同时,对单核淋巴细胞因子的检测有助于防治术后切口感染的发生。