摘要:

The family Togaviridaecomprises four genera: Alphavirus (with 26 species), Rubivirus (one species), Pestivirus (three species), and Arterivirus (one species). The main characteristics of the member viruses are: (i) the virus particles are spherical, 50–70 nm in diameter, including an envelope with surface projections that incorporate two or three polypeptides, usually glycosylated; (ii) the nucleocapsid comprises a core protein and a single strand of positive-sense RNA, molecular weight about 4 x 106; where characterized, the RNA has an m7G ‘cap’ at the 5’ end and is polyadenylated at the 3’ end; (iii) maturation occurs by budding of spherical nucleocapsids 30–35 nm in diameter, with proven or presumed icosahedral symmetry, through cytoplasmic membranes. Where characterized, translation of structural proteins occurs on subgenomic messenger RNA(s); these appear to represent the 3’ end of the genome. Nearly all alphavirus species are transmitted by mosquitoes. Transmission also occurs transovarially (Alphavirus) or transplacentally (Rubivirus and Pestivirus). Members of a genus are serologically related, but are not related to members of

ISSN:0300-5526    

DOI:10.1159/000149632

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Studies are reported on two outbreaks of epidemic diarrhea in China involving 19,007 patients. The first outbreak occurred in the northern part of the Guangxi Autonomous Region and extended south from April through September 1983. In June 1984 a second outbreak of 6,570 cases occurred in Guanyang, a county in the northern part of Guangxi. 125 fecal samples from the two outbreaks were cultured for bacteria; all of the samples except one were negative. Rotavirus particles were detected in 44.1% (15/34) of stool specimens examined by immune electron microscopy. The two outbreaks appeared to be caused by non-group-A rotaviruses, based on the pattern of electrophoretic migration of the RNA genome segments in polyacrylamide gels and on the lack of a detectable common group antigen(s) when tested by an enzyme-linked immunosorbent assay for group A rotaviruses. Complement-fixation tests also indicated that 37.5% of convalescent-phase sera from patients produced antibody to the isolated rotavirus. The total molecular weight of the RNA segments in the new Guangxi strain was calculated to be 10.69 × 106, with the 11 genome segments having molecular weights (×106) of 2.19,1.83,1.56,1.53, 0.82, 0.81, 0.60,0.46,0.35, 0.30, and 0.24. This study also reports comparative detection rates for direct and immune electron microscopy and for PAGE. PAGE proved to be the most sensitive detection method for these new rotaviruse

ISSN:0300-5526    

DOI:10.1159/000149633

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

M14virus, isolated from Culex tritaeniorhynchus mosquitoes collected in a Beijing suburb, was identified as a noncytopathogenic orbi-like virus. It was found to interfere with the growth of Japanese encephalitis (JE) virus, a mosquito-borne virus which infects humans, pigs, and horses in much of Asia, including China. JE virus is transmitted by C. tritaeniorhynchus mosquitoes and causes encephalitis in humans and horses and abortion in pigs. Because it had potential as an interfering agent for the biological control of JE, the M14virus was characterized and its interfering effect was studied in mice and in C. tritaeniorhynchus mosquitoes.

ISSN:0300-5526    

DOI:10.1159/000149634

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The effects of cyclosporin A (CsA) upon the pathogenesis of primary cytomegalovirus (CMV) infection were investigated. Hartley and strain 2 guinea pigs were inoculated subcutaneously on day 0 with 104 TCD50 of virulent, salivary-gland-passaged guinea pig CMV and received oral CsA (20 mg/kg/day) for 14 days. CMV-infected, CsA-treated animals lost approximately 20% of their total body weight in 14 days and had more than twice the rate of CMV isolation from internal organs when compared with untreated controls, despite similar rates of viremia. Internal organs of CsA-treated animals demonstrated widespread viral inclusions and minimal inflammatory response to the presence of CMV-infected cells. The mean change in peripheral blood lymphocyte values for CMV-infected, CsA-treated Hartley guinea pigs was -2,867 ± 2,955 (mean ± SD) lymphocytes/µl as compared to +10,933 ± 7,583 in CMV-infected, untreated controls (p < 0.01). In the guinea pig model, CsA administration had adverse effects upon the pathogenesis of primary CMV infect

ISSN:0300-5526    

DOI:10.1159/000149635

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The effect of concanavalin A on rabies virus infection of CER cells was investigated. Pretreatment of CER cells with concanavalin A inhibited cellular susceptibility to rabies virus infection. The lectin also was found to be inhibitory when applied after the viral binding step. Moreover, the lectin had a direct inhibitory effect on the infectivity of the virion. These lectin-mediated inhibitions could be reversed by α-D-methyl-mannopyranoside. These complex effects are discussed with regard to the mechanism of rabies virus entry into CER cells

ISSN:0300-5526    

DOI:10.1159/000149636

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Injection of mice with thioglycolate 5 days prior to intraperitoneal injection of scrapie brain homogenate led to a statistically significant increase in scrapie incubation periods. This was seen with two different scrapie strains (ME7 and 139A), in different mouse strains (C57BL/6J and Compton White), and at several dilutions of the scrapie inoculum.

ISSN:0300-5526    

DOI:10.1159/000149637

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Mouse adenovirus multiplies, apparently without impediment, in temperature-inactivated ts A1S9, ts C1 and ts 2 mouse fibroblasts. Thus, the DNA of mouse adenovirus can replicate in the absence of functional DNA topoisomerase II, a DNA-chain-elongation factor, and a protein required for traverse of the Gi/S interface, respectively, encoded in the ts A1S9, ts C1 and ts2 genetic loci. These results are compared with those obtained with polyoma virus.

ISSN:0300-5526    

DOI:10.1159/000149638

出版商:S. Karger AG    

年代:1985

数据来源: Karger