摘要:

AbstractImmune elimination of alphaviruses in immunized hamsters appears to involve formation of virus/antibody aggregates which are subsequently cleared from the circulation by cells of the reticuloendothelial system (RES). Virulent strains of Venezuelan (VEE) and Western equine encephalitis (WEE) viruses which were cleared slowly from the circulation of nonimmune hamsters, were cleared rapidly when inoculated into the blood of immunized hamsters. Likewise, when these viruses were mixed with specific hamster immune serum prior to inoculation, they were efficiently cleared from the circulation of nonimmune hamsters. Virus, mixed with specific immune serum, or inoculated into immunized hamsters, formed virus/antibody aggregates, as demonstrated by density gradient centrifugation, filtration through polycarbonate membranes, precipitation with Staphylococcus protein A, and electron microscopy. Cleared virus was concentrated primarily in liver and spleen, as confirmed by autoradiography. Immune clearance of virulent VEE was demonstrable within 5 to 6 days following immunization of hamsters with live attenuated VEE vaccine, strain TC‐83. In these hamsters, a close association was established between formation of virus/antibody aggregates, rapid clearance, and survival of challenged hamsters. Adsorption of virus to hamster macrophages in culture was enhanced by immune serum in the presence of complement. These results are compatible with the hypothesis that immune clearance of virus in the intact hamster involves a complement‐dependent interaction of virus/antibody complexes with cells which possess Fc and complement receptors. The clearance of immune complexes by the RES serves to amplify the protective effect of neutralizing antibody al

ISSN:0146-6615    

DOI:10.1002/jmv.1890120102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractTo investigate the frequency of natural reinfection with influenza A viruses, 55 children followed from birth along with the 44 other children and 85 adults in their families were observed for varying periods between 1975 and 1981 in the Houston Family Study. Persons infected in 1976 or early 1977 with influenza A subtype H3N2 experienced a high rate of reinfection during the 1977–78 season (63% in one group of young children) and additional reinfections in 1980–81. Persons in whom H3N2 infection was first observed in 1977–78 had little or no reinfection in 1980–81; one reinfection was observed in 1980–81 among 19 young children at risk. Only one reinfection with influenza A subtype H1N1 was observed following introduction of the virus in early 1978 despite exposure in 1978–80 and a substantial outbreak in 1980–81. Statistically significant protection from reinfection in young children followed from birth was not noted for the 1977–78 H3N2 outbreak but was present in 1979–81 for both H3N2 and H1N1 viruses. Reasons for variations in reinfection suggested by this data include (1) socioeconomic and other factors influencing intensity of exposure, (2) age at primary infection, (3) varying degrees of antigenic difference between sequential variants of a major subtype, and (4) unrecognized immunogenicity or virulence differences between subt

ISSN:0146-6615    

DOI:10.1002/jmv.1890120103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractMarmoset herpesvirus (MarHV) deletion mutants in the thymidine kinase (TK) gene were isolated after infection of OMK cells with TK+MarHV DNA and the hybrid plasmid, pMAR401, which lacks a 2.6‐kb KpnI‐M fragment in the coding region of the MarHV TK gene. After plaque purification in TK−HeLa(BU25) cells, the DNA's from five recombinant araT‐resistant MarHV clones were analyzed with restriction nucleases to verify that the 2.6‐kb KpnI‐M fragment (and a 0.9‐kb Bg1II‐Q fragment) were deleted from the viral DNA's. Molecular hybridization experiments using32P‐labeled pMAR4 probes and viral DNA fragments also showed that the recombinant viral DNA's lacked the KpnI‐M and Bg1II‐Q fragments, that BamHI‐I of parental virus was shortened, and that three new HindIII fragments replaced the parental virus HindIII‐G fragment. The recombinants did not induce TK activity in LM (TK−) cells. To study the relative virulence of the recombinants, 3‐week‐old Swiss mice were injected intracerebrally (Ic) or subcutaneously (Sc) in the sacro‐lumbar region with either parental or recombinant viruses. The LD50for the parental virus was 3 p.f.u. (Ic) and 7,600 p.f.u. (Sc). The recombinant viruses were significantly less virulent than TK+MarHV after Ic inoculation (LD50of 62,000 and 32,000 p.f.u., respectively, for viruses 5D‐6B and 5D‐4B) and gave no fatalities after Sc inoculation. Mice surviving TK−MarHV infections were protected from challenge with TK+parental MarHV. Recombinant TK−MarHV's may be useful as vectors for the expression of foreign genes in animal cells and as the sta

ISSN:0146-6615    

DOI:10.1002/jmv.1890120104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractBK virus (BKV) DNA was detected by blot hybridization in a human adenoma of pancreatic islets from patient I.R. BKV DNA was free, and no evidence was found of viral sequences integrated into cellular DNA. Virus was rescued by transfection of human embryonic fibroblasts with tumor DNA. The DNA from rescued virus (BKV‐IR) was different from wild‐type BKV DNA by restriction endonuclease mapping. The genome of BKV‐IR is 235 base pairs (bp) shorter than the genome of wild‐type BKV. This alteration originates from a deletion of approximately 300 bp involvingHindIII fragments B and D, and an insertion of 70 bp in the region ofHindIII fragment C. Transformation of hamster kidney cells was induced by total tumor DNA as well as by BKV‐IR and BKV‐IR DNA. No antibodies to BKV tumor (T) antigen were detected in the patient's serum by immunofluorescence. The significance of episomal BKV DNA in a human tumor i

ISSN:0146-6615    

DOI:10.1002/jmv.1890120105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractDuring July 1979, ten patients were admitted to the hospital with bloody diarrhoea followed by manifestations of haemolytic uraemic syndrome (HUS): acute microangiopathic haemolytic anaemia, intravascular coagulopathy, and impaired renal function. Ages ranged from 13 months to 58 yr, with only two patients more than 5 yr old. In a household that included seven children born to three sisters who married three brothers, six children required hospitalization for bloody diarrhoea and four developed HUS; the father of one case and the maternal grandmother also developed bloody diarrhoea. Echovirus type 11 was isolated from the pharyngeal secretions or faeces of all members of the household with bloody diarrhoea, with the exception of the grandmother. Picornavirus‐like particles were seen by direct electron microscopy (E/M) in faeces from four other HUS patients and an adenovirus in one, but these viruses failed to replicate in cell cultures. Parvovirus‐like particles were seen by E/M in faeces from six patients. Serological examination indicated recent infection with one or more enteroviruses (echovirus 11, coxsackieviruses A4, B2, B4) in nine cases. Combined viral studies revealed presumptive evidence of recent infection with two or more viruses in all of the patients with HUS. Stools were negative for bacterial pathogens including campylobacter, salmonella, shigella, and yersinia organisms. Only one of nine patients tested had circulating immune complexes. Our data support the concept that the pathology seen in HUS may be due to a Shwartzman‐type reaction provoked by concurrent infection with two or more viral a

ISSN:0146-6615    

DOI:10.1002/jmv.1890120106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThis paper describes an assay for hepatitis B DNA polymerase which is based on the use of phosphonoformic acid (PFA), a known inhibitor of the viral enzyme, with particulate fractions prepared from blood plasma or serum. The assay makes possible the measurement of the viral enzyme activity in the presence of DNA polymerases unrelated to hepatitis B. The activities of the latter were largely but incompletely suppressed in the presence of 0.4 M KCl, and they were altogether excluded from nucleotide incorporation which was inhibited by PFA. Thus, particulate fractions obtained from HBsAg‐negative blood had mean DNA polymerase activities of 1 ± 1 (SD) pmol/liter/hr with a lower 90th percentile range of 0–3 pmol/liter/hr. Particulate fractions prepared from blood that was positive for both HBsAg and HBeAg had polymerase activities of 58 ± 66 pmol/liter/hr with an upper 90th percentile range of 4–322 pmol/liter/hr. PFA concentration was optimized using a commercial preparation of the inhibitor, in which the degree of purity was determined. The method utilizes3H‐labeled deoxyribonucleoside triphosphates and is performed on 6 ml of plasma or serum. The effects of precursor concentration and specific activities on the rate of nucleotide incorporation were studied, and the optimal combinations were indicated. Other parameters of the proposed assay were als

ISSN:0146-6615    

DOI:10.1002/jmv.1890120107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractRotavirus RNA was extracted from stools collected from children with gastroenteritis in two hospitals in Rotterdam. Electrophoresis of the RNAs showed that at least 19 different electropherotypes were isolated from stools collected in the period from 1977 to 1982. It was possible to identify the index case in some hospital‐acquired cases of rotaviral gastroenteriti

ISSN:0146-6615    

DOI:10.1002/jmv.1890120108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

ISSN:0146-6615    

DOI:10.1002/jmv.1890120109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

ISSN:0146-6615    

DOI:10.1002/jmv.1890120101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY