用标记分析法检测我国海南省登革2型病毒抗原性变化

我们试用标记分析法,用3种单克隆抗体(黄病毒科特异性、登革病毒属特异性和登革病毒2型型特异性单克隆抗体)研究了我国海南省1985～1987年3年内流行的登革2型病毒8个流行株的抗原性变化,并与标准株新几内亚B株进行了比较。发现6株与标准株类似,2株显示出明显的差异。标记分析法为病毒抗原分析提供了一个简便、快速的方法,可用来监测一个地区病毒株群的变化及新株的传入。     

Inhalation anesthetic-induced neuroinvasion by an attenuated strain of West Nile virus in mice

There are contradictory reports regarding the effects of inhalation anesthetics on the immune system. Measurable immune responses have been studied in vitro, but little is known about the in vivo effects in the intact organism. We used an attenuated, non-neuroinvasive, nonlethal strain of the encephalitic West Nile virus, termed WN-25, which can become lethal in combination with environmental stressors, to study possible modulatory immune effects of inhalation anesthetics in mice. Both single short-term exposure and repeated exposure to halothane and nitrous oxide were studied. Exposure to 30% CO2 served as a positive control. Mortality, brain invasion, spleen weight, and antiviral antibodies served as the experimental endpoints. Halothane and nitrous oxide led to viral brain invasion, increased mortality, and suppressed immune response in a concentration- and time-dependent manner. Repeated exposures had a cumulative effect. Assessment of the stability of the viral attenuation did not demonstrate any alteration in the character of the virus, suggesting an increased access to the brain by inhalation anesthetics that led to the fatal encephalitis. These findings may be of special concern to populations at risk, such as operating room staff and patients undergoing general anesthesia in endemic areas of encephalitic virus species, in which subclinical infection may develop into an overt disease.     

Chronic hepatitis C infection: influence of the viral load, genotypes, and GBV-C/HGV coinfection on the severity of the disease in a Brazilian population

The distributions of the different genotypes of the hepatitis C virus (HCV) and GBV-C virus (GBV-C/HGV) vary geographically and information worldwide is still incomplete. In particular, there are few data on the distribution of genotypes (and their relationship to the severity of liver disease) in South America. Findings are described in 114 consecutive patients from Northeast Brazil (median age 52 years, range 18-72 years) who had abnormal levels of serum aminotransferases and seropositivity for HCV RNA. The patients were recruited from an outpatient clinic between November 1997 and April 1998. Quantitative HCV RNA and GBV-C/HGV RNA estimations were carried out by double-nested polymerase chain reaction (PCR) using primers from the 5'-untranslated regions (UTRs) of the genomes. HCV genotypes were determined by restriction fragment length polymorphism (RFLP) analysis with 5'-UTR primers and by PCR with type-specific 5'-UTR primers. GBV-C/HGV-RNA genotypes were determined by RFLP with specific 5'-UTR primers and phylogenetic trees were constructed using the Neighbour-Joining and Drawtree programs. Histological features were graded and staged according to international criteria. Of the 114 patients, 35 (30.7%) patients had cirrhosis and 22 (27.8%) had mild, 51 (64.6%) had moderate, and 6 (7.6%) had severe chronic hepatitis. Median HCV viral load was 10(6) genome equivalents per millilitre (range 10(4)-10(9)/ml). Frequencies of genotypes were 5.3% type 1a, 44.7% type 1b, 3.5% type 2, 41.2% type 3, and 5.3% mixed types. GBV-C/HGV-RNA was detected in the sera of 12 (10.5%) patients and was distributed among three phylogenetic groups. There were no significant differences between patients with the predominant HCV genotypes (1b and 3) with respect to gender, age group, viral load, severity of liver disease, or coinfection with GBV-C/HGV.     

甘肃省SARS抗体血清流行病学调查

目的 了解甘肃省严重急性呼吸综合征(SARS)患者、密切接触者和正常人群血清SARS冠状病毒特异性IgG抗体水平。方法 利用酶联免疫吸附试验(ELISA)法检测SARS病毒IgG抗体水平。检测对象包括甘肃省9例SARS患者的急性期和(或)恢复期系列血清，l109例直接护理SARS患者的医生、护士、实验室检测人员、疾控人员和曾与患者有接触的人员以及978例正常人血清。结果 9例临床诊断病例SARS冠状病毒特异性IgG抗体中6例为阳性，疾病恢复后12个月血清抗体仍为阳性；密切接触者1例特异性IgG抗体阳性；正常人3例特异性IgG抗体阳性。结论 病例抗体阳性符合临床诊断，密切接触者和正常人的抗体阳性数较低，提示可能不存在隐性感染。     

呼吸道合胞病毒M2-1蛋白多克隆抗体的制备

目的:制备呼吸道合胞病毒(RSV)M2-1蛋白多克隆抗体, 为进一步研究RSV生物学特性奠定基础。方法:纯化RSV M2-1蛋白, 免疫新西兰家兔, Western blot检测M2-1多克隆抗体效价。结果:Western blot检测可见约48 kD的特异性条带, M2-1蛋白多克隆效价为1:1000。　结论：本实验成功的地制备了RSV M2-1蛋白多克隆抗体。     

Prolonged hepatitis A infection in an HIV-1 seropositive patient

Hepatitis A virus (HAV) is a worldwide disease; in most cases, it causes an acute self-limited illness that does not lead to a chronic state. The course of HAV viremia in a homosexual male with human immunodeficiency virus type 1 (HIV-1) and the correlation between HIV and HAV viral load, alanine aminotranferase (ALT) level, and CD4(+) lymphocyte count were investigated during the course of the infection. HAV RNA was detected quantitatively up to 256 days after clinical onset. To our knowledge, this specific case is the first report of a prolonged infection with hepatitis A in a male with HIV-1. The ALT levels decreased gradually; however, 286 days after clinical onset of hepatitis, ALT levels were three times higher than normal values. HIV viral load was not affected by the infection with HAV and CD4(+) cell count was stable during the course of the co-infection. The duration and the high-titer viremia of hepatitis A virus in an immunodeficient patient constitute a serious risk of the spread of hepatitis A within this population. As inactivated HAV vaccine is safe in HIV-positive subjects, it would be wise to establish a strategy of preventive vaccination in this high-risk group.     

Mixed microbial aetiology of community-acquired pneumonia in children

Seven paediatric studies on community-acquired pneumonia with serological methods for both viruses and bacteria have been published, allowing the evaluation of concomitant multiple etiological findings. In these studies, dual viral infection has been present in 0-14%, dual bacterial infection likewise in 0-14%, and mixed viral-bacterial infection in 3-30% of the pneumonia cases. The results confirm former clinical observations that respiratory viruses often pave the way for airway-colonising bacteria. The measured frequency of multiple infections has been dependent on the available test panel, mainly on the tests used for pneumococcal aetiology. Mixed viral-bacterial infections have been especially common in young children under 2 years of age, reflecting the high frequency of respiratory syncytial virus infections and their tendency to induce bacterial co-infections. No microbe-specific viral-bacterial associations have been demonstrated. The clinical implications of mixed viral-bacterial infections, compared with viral infections alone or bacterial infections alone, have so far remained unresolved. Current guidelines recommend antibiotic therapy for all community-acquired pneumonia cases in children.     

EB病毒LMP2A特异性CTL的体外诱导及分析

用EBV LMP2A重组痘苗病毒 (rVV LMP2A )转染人树突状细胞 (DC ) ,转染后的DC分别在第 1、 7、 14天刺激相同MHC背景的T细胞 ,在IL 2作用下诱导LMP2A特异性CTL。用LDH释放法检测CTL杀伤活性 ;流式细胞术 (FACS )检测CTL诱导分化过程中CD3+ 、CD4 + 、CD8+ 、CD5 6 + 等细胞的分群变化 ;RT PCR检测细胞分化过程中FasLmRNA表达 ;生物活性法检测功能性细胞因子IFN γ的分泌。结果显示本法诱导的CTL对靶细胞有特异性杀伤活性 ,第 2次和第 3次DC刺激后杀伤活性有所上升 ;在CTL诱导分化的第 7、 14、 2 1天细胞分群以CD4 + 、CD8+ 细胞为主 ;RT PCR证实所诱导的细胞内有FasLmRNA的表达 ;随细胞培养天数的增加IFN γ分泌增加 ,在第 14天达到较高水平。研究表明重组痘苗病毒载体rVV LMP2A转染的DC刺激T细胞可诱导出EBV LMP2A特异性CTL。     

SARS冠状病毒的病原生物学分析及其启示

Severe acute respiratory syndrome (SARS) is the first new epidemic of the twenty - first century. A novel coronavirus (SARS - CoV) has been identified as the causative agent of SAP, S. The genome of SARS - CoV has 29,727 nucleatides in length. The genome organization, with 11 open reading flames, is similar to that of conronaviruses.Phylogenetic analyses and sequence comparisons showed that SARS- CoV is not closely related to any of the known coronaviruses, indicating neither a mutant nor recombinant of well -characterized coronaviruses. It is a complete new coronavirus from nonhuman hostPathological studies show that severe immune response, associated to cytokine dysregulation, may be related to the lung damage of fatal SRAS. Recombination of genomes of wild - type strains with vaccine coronavirus is a potential risk associated with the application of living attenuated coronavirus vaccines. The proteinases, controlling the activities of the SARS- CoV replication, and spike protein, involved in viral entry and pathogenesis, represent attractive targets of anti- SARS drug development. Comparative full-length genome sequence analysis of 14 SARS coronavirus isolates suggests a remarkable genetic conservation of the virus. Anti - SARS vaccine and drug development will benefit from this genetic conservation. SARS-CoV is not likely to change rapidly and thus may not readily mutate to a benign infection. The progress in anti - SARS research has been impressive. However, one of the most effective tools in the control of the SARS is quickly tracing and isolating the contacts of stricken patients before they spread the virus further.     

A genomic map of infectious laryngotracheitis virus and the sequence and organization of genes present in the unique short and flanking regions

We present a genomic map of infectious laryngotracheitis virus (ILT) and an 18,912 bp sequence containing the entire unique short region and a portion of the flanking short repeats. In determining the genomic map, an 856 bp region repeated as many as 13 times was identified within the short repeats. The unique short sequence contains nine potential open reading frames (ORFs). Six of these ORFs show homology to other known herpesvirus unique short genes. Using the herpes simplex virus nomenclature, these genes are the US2, protein kinase, and glycoproteins G, D, I, and E (ORF 1, 2, 4, 6, 7, and 8, respectively). Interestingly, an open reading frame with homology to HSV-1 UL47 (ORF 3) is found in the unique short. One very large open reading frame (ORF 5) is present and contains a threonine-rich, degenerate repeat sequence. This gene appears to be unique to ILT among sequenced herpesviruses. Two ORFs were identified within the short repeat (SR) region. SRORF 1 is homologous to a gene (SORF3) found in the unique short region in both MDV and HVT, and appears to be specific to avian herpesviruses. SRORF 2 has homology to HSV US10.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence data-base and have been assigned the accession number U28832.