用逆转录PCR-核酸探针杂交法对柯萨奇B组病毒分型诊断

目的 建立一种逆转录PCR-核酸探针杂交法对柯萨奇B组病毒(CVB1～6)进行分型诊断。方法 一对通用PCR引物，它能有效扩增所有CVB1-6型的特异性DNA片段；另选取6条各型特异性寡核苷酸探针，将它们分别共价结合在不同的微孔板上。经过一次PCR扩增，扩增后的产物分别与包被有不同探针的微孔板进行杂交检测，从而有效鉴别CVB各型。结果 本法与ELISA法的分型比较显示它们具有很好的一致性，无错误分型。对152例IgM抗体阳性标本的检测，该方法阳性率为71．7％。结论 本法可准确对CVB进行分型，为CVB的临床诊断及流行病学调查提供了一种有效的方法。     

Incidence and case-fatality rates resulting from the 1998 enterovirus 71 outbreak in Taiwan

In 1998, an epidemic of hand-foot-and-mouth disease and herpangina caused by enterovirus 71 occurred in Taiwan, leaving many fatalities and severely handicapped survivors in its wake. The reasons this rather common pathogen would cause such a large-scale epidemic remain unknown. A seroepidemiological survey to elucidate the epidemiological characteristics of this outbreak, including its incidence and case-fatality rates was undertaken. Microneutralization tests for antibodies against enterovirus 71 were used to screen four collections of serum samples: 1) 202 specimens taken from individuals > or = 4 years old in 1994; 2) 245 specimens collected from individuals of all ages in 1997; 3) 1,258 specimens collected from individuals of all ages in 1999; and 4) sera samples from a birth cohort of 81 children who had yearly blood samples taken from 1988-98. After the maternal antibody had declined, the seropositive rates began to increase with age. Approximately half of all children aged 6 years or older were enterovirus 71 seropositive. Significantly higher seropositive rates were noted in 1999 than in 1997, in children aged 0.5-3 years. The incidence of enterovirus 71 infection during the epidemic was estimated to be 13-22%, with the higher rates in younger children. The case-fatality rate was highest (96.96 per 100,000) in infants aged 6-11 months, and declined in older children. The results showed that enterovirus 71 is endemic in Taiwan. The apparent lack of large-scale enterovirus 71 activity in the 3 years before 1998 might have been the prelude to the epidemic's appearance in 1998, and might suggest that enterovirus 71 infection will reappear every few years. The lack of a protective antibody in younger children may account for the high incidence and case-fatality rate in this age group.     

RNA interference against enterovirus 71 infection

Enterovirus 71 (EV71) is a highly infectious major causative agent of hand, foot, and mouth disease (HFMD) which could lead to severe neurological complications. There is currently no effective therapy against EV71. In this study, RNA interference (RNAi) is employed as a therapeutic approach for specific viral inhibition. Various regions of the EV71 genome were targeted for inhibition by chemically synthesized siRNAs. Transfection of rhabdomyosarcoma (RD) cells with siRNA targeting the 3'UTR, 2C, 3C, or 3D region significantly alleviated cytopathic effects of EV71. The inhibitory effect was dosage-dependent with a corresponding decrease in viral RNA, viral proteins, and plaque formations by EV71. Viral inhibition of siRNA transfected RD cells was still evident after 48 h. In addition, no significant adverse off-target silencing effects were observed. These results demonstrated the potential and feasibility for the use of siRNA as an antiviral therapy for EV71 infections.     

用RACE技术对一株肠道病毒3''端进行扩增和序列分析

目的 应用3′RACE技术对一株本室分离肠道病毒基因组3′末端进行扩增，并对其核苷酸序列进行比较分析。方法 提取病毒总RNA，以锚定oligdT（17）引物进行逆转录，用特异引物及锚定引物进行3′RACE扩增，将PCR产物进行克隆、测序和序列分析。结果 获得了该病毒的3′端核苷酸序列，同源性分析结果显示该肠道病毒的核苷酸序列与肠道病毒76、89、90、91型的同源性最高为90％左右，而与其他型别的肠道病毒的同源性均小于80％；推导的氨基酸同源性与肠道病毒76、89、90、91型均在90％以上。结论 用RACE技术对肠道病毒3′端进行扩增及序列分析，证明该病毒属新型肠道病毒类，为进一步研究该病毒的分子生物学特性奠定了基础。     

肠道病毒71型灭活疫苗的卫生经济学评价:包括手足口病后遗症损失

目的 结合手足口病后遗症造成的经济损失与健康寿命损失,评估EV71疫苗接种的流行病学效果与成本效益。方法 构建Markov模型,采用成本效益分析,比较1 500万新生儿在30%覆盖率接种与不接种疫苗两种策略下的临床事件与经济学结果,模型参数来源于公开数据库或已发布数据。结果 1 500万新生儿接种EV71疫苗（覆盖率30%）可以避免1 210 434例手足口病发病,4 757例重型,242例后遗症以及72例死亡,挽救38 762.94个质量调整寿命年（QALYs）。成本仅包括疫苗接种成本与手足口病疾病负担时,增量成本效益比（ICER）为27 792.01元/QALY。成本包括后遗症经济损失时,疫苗接种人均净效益为396.70元。敏感性分析提示,疫苗价格阈值为397.05元每剂。结论 接种EV71疫苗能减少手足口病临床事件发生,具有成本效益,有利于改善手足口病疾病现状,降低疾病负担。     

宁河区手足口病肠道病毒检测及流行特征分析

目的了解手足口病(HFMD)病原学特点及主要流行特征,为HFMD疫情的控制和常规监测提供可靠的数据。方法选取2017年1月-2019年12月天津市宁河区医院肠道门诊及儿科住院部HFMD病例的粪便样本382份进行检测。采用实时荧光定量PCR法,对手足口病毒进行分型检测。结果 2017年1月-2019年12月宁河区HFMD年均发病率为31.83/10万;2019年发病率最高为34.00/10万;2017年发病率最低为29.25/10万。在382份粪便标本中,肠道病毒分型EV、EV71、CV-A6、CV-A10、CV-A16阳性检出率分别为15.71%、5.24%、56.81%、1.83%、20.41%,其中CV-A6型阳性率高于其他分型。男孩病毒核酸阳性检出率高于女孩,25岁的年龄段检测阳性率最高,发病高峰集中在78月和10月。结论近三年宁河区HFMD发病分型以CV-A6感染为主,多无典型临床症状,无重症病例。因HFMD主要通过呼吸道的飞沫及粪便传播,传播速度相对较快,需进一步加强辖区内HFMD检测和宣传力度,培养孩子良好的卫生习惯,减少发病患儿与他人的玩具和日常用品之间的直接接触,做到早发现、早医治、早隔离,从而减少辖区内HFMD的发病率。     

A molecular scheme for the reaction between γ-aminobutyric acid and the most abundant chloride channel on crayfish deep extensor abdominal muscle

Single-channel measurements were performed with the aim of constructing a detailed molecular scheme for the reaction between -aminobutyric acid (GABA) and a chloride channel of crayfish deep extensor abdominal muscle (DEAM). GABA was applied in pulses to outside-out patches of muscle membrane, and, based on the dose-response of the peak currents and of their rise times, a linear model with five binding steps has been proposed. Evaluation of the single-channel kinetics indicated at least three open states. Two of them originate most probably from the fully liganded receptor state and are grouped in mixed bursts due to their different life times. The third one appears independently, outside the bursts, and originates from a lower liganded receptor state. Simulations of the dose-responses and the open time distributions with this model led to a set of rate constants which generated relatively optimal fits.     

Prognostic factors in multiple myeloma: role of β2-microglobulin and thymidine kinase

Summary Serum ₂- microglobulin, serum thymidine kinase, and commonly used prognostic parameters were investigated for their prognostic value in a well-defined group of patients with multiple myeloma (n = 207). Multivariate analysis showed hemoglobin to be the parameter of strongest prognostic value. Only albumin, serum ₂-microglobulin and serum thymidine kinase added further prognostic information. When tested for efficiency in recognizing patients with poor (average survival time < 1 year) and good (average survival time > 5 years) prognosis, serum ₂-microglobulin was best (80%), followed by total urinary protein (78%), hemoglobin (76%), and albumin (75%).     

Characteristics of pentobarbital discrimination in the gerbil: Transfer and antagonism

Experiment 1. Gerbils were trained in a T-shaped maze to discriminate the effects produced by pentobarbital (P-barb. 15 mg/kg, i.p.) and the effects of saline. The response, a left or right turn in the maze, was thus contingent upon the prevailing training condition (P-barb. or saline). The criterion of performing 8 correct first trial choices in 10 consecutive sessions was reached within 20 training sessions. Tests with descending doses of P-barb. yielded an ED₅₀ of 9 mg/kg. Tests with phenobarbital (40 mg/kg) or diazepam (2 and 4 mg/kg) solely maintained the drug response. P-barb. discrimination was reversed by megimide (ED₅₀: 8.5–9.6 mg/kg) and metrazol (ED₅₀: 24.9–27.9 mg/kg). Thus megimide was approximately 3 times more effective than metrazol. Metrazol (40 and 80 mg/kg) also counteracted the phenobarbital and diazepam response. Picrotoxin (2.5 and 5 mg/kg) was less effective whereas caffeine (100 mg/kg) and piracetam (100–1000 mg/kg) did not upset P-barb. discrimination. Experiment 2. Naive gerbils had to discriminate mixtures of P-barb. (15 mg/kg) plus either 40 or 80 mg/kg of metrazol from saline already at the start of the discriminative training. The drug combinations produced discriminable effects since most gerbils reached the acquisition criterion (8/10), although more slowly than gerbils trained with P-barb. solely. Gerbils trained without a drug stimulus (saline vs. saline) never attained the criterion during 60 consecutive sessions. In conclusion, reversal of established discrimination (Expt. 1) does not necessarily mean that the same drug combination lacks discriminable effects as demonstrated in Experiment 2.