摘要:

The family Coronavirtdae comprises a monogeneric group of 11 viruses which infect vertebrates. The main characteristics of the member viruses are: (i) Morphological: Enveloped pleomorphic particles typically 100 nm in diameter (range 60–220 nm), bearing about 20 nm long club-shaped surface projections, (ii) Structural: A single-stranded infectious molecule of genomic RNA of about (5–7) × 106 molecular weight. A phosphorylated nucleocapsid protein [mol.wt. (50–60) × 103] complexed with the genome as a helical ribonucleoprotein; a surface (peplomer) protein, associated with one or two glycosylated polypeptides [mol.wt. (90–180) × 103]; a transmembrane (matrix) protein, associated with one polypeptide which may be glycosylated to different degrees [mol.wt. (20–35) × 103]. (iii) Replicative: Production in infected cells of multiple 3’ coterminal sub genomic mRNAs extending for different lengths in the 5’ direction. Virions bud intracytoplasmically. (iv) Antigenic: 3 major antigens, each corresponding to one class of virion protein, (v) Biological: Predominantly restricted to infection of natural vertebrate hosts by horizontal transmission via the fecal/oral route. Responsible mainly for respiratory and gastroint

ISSN:0300-5526    

DOI:10.1159/000149390

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Serological mass surveys were carried out in Zangwu County, China, using an immunoenzymatic test. 3,533 persons were found to have Epstein-Barr virus (EBV) IgA/VCA antibody among 148,029 persons age 30 years and older who were tested during 1978–1980. Among the IgA/VCA antibody-positive persons, 55 nasopharyngeal carcinoma (NPC) cases were detected. Follow-up studies were carried out yearly on the IgA/VCA antibody-positive persons for 1–3 years, and 32 additional NPC patients were diagnosed. IgA/VCA antibody was detected 8–30 months (average, 13 months) prior to the clinical diagnosis of stage I NPC. There was no marked difference in geometric mean titers of IgA/VCA antibody between the period before onset of NPC and after diagnosis at stage I, but antibody titers were higher during stages II-IV. The NPC detection rates for all persons tested serologically and for IgA/VCA antibody-positive persons, respectively, was 2- and 82-fold the annual incidence of NPC in the general population of the same age group. These data further indicate that serological testing is valuable for the diagnosis of NPC, especially in its early stages, and that EBV may play an important role in the development o

ISSN:0300-5526    

DOI:10.1159/000149391

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Infection of guinea pigs with an attenuated strain of Junin virus (JV) produced 16% mortality between days 17 and 27 postinfection (p.i.)· The morphological study showed a marked pancreatitis between days 6 and 23 p.i. and meningoencephalitis between days 17 and 20 p.i. in a large proportion of the animals. These lesions were coincident with the presence of JV antigenic determinants in the pancreatic acinar cells, neurons and blood vessels of the brain. Infectious virus could be isolated from lymph nodes, spleen, bone marrow, lungs, adrenal glands, and brain. The lesions appeared to be reversible, as they were absent in animals studied after day 64 p. i. Meningoencephalitis, present in all animals dying spontaneously, appeared to be the most important cause of death. Our observations indicate that more accurate markers of virulence must be investigated in the search for attenuated strains of JV as potential vaccine candidates for Argentine hemorrhagic fever

ISSN:0300-5526    

DOI:10.1159/000149392

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Colposcopic-directed biopsies of the uterine cervix from 22 patients were analyzed for the presence of human papillomavirus (HPV) DNA and structural antigens. 11 of the biopsies were classified microscopically as mild dysplasia, 3 as moderate dysplasia, 1 as severe dysplasia, and 7 as squamous metaplasia. Nonstringent hybridization with a bovine papillomavirus type 1 DNA probe and immunocytochemical analysis with an antiserum against papillomavirus genus-specific structural antigens were performed on all specimens. Of the 11 mild dysplasias, both HPV DNA and structural antigens were detected in 5, only HPV antigens in 3, only HPV DNA in 1, and neither DNA nor structural antigens in 2. Both HPV DNA and structural antigens were present in the 3 cases of moderate dysplasia. Only HPV DNA sequences were detected in the single case of severe dysplasia. HPV DNA was detected in 2 cases of squamous metaplasia. The 5 remaining cervical biopsies showing squamous metaplasia, tissue from 3 placentas, and 6 cervical carcinomas were negative for HPV DNA and structural antigens. Restriction enzyme cleavage patterns of HPV DNA in the dysplasias suggested that there are multiple virus types or subtypes associated with cervical dysplasia. Stringent hybridization with a HPV type 11 (HPV-11) probe revealed that only 1 of 10 dysplasias contained sequences with homology to the probe. Of the remaining 9 dysplasias, 5 contained HPV sequences detected under nonstringent hybridization. 2 of 4 squamous metaplasias contained viral sequences which hybridized to the HPV-11 probe as well as 1 of 6 cervical carcinomas.

ISSN:0300-5526    

DOI:10.1159/000149393

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The Epstein-Barr virus(EBV)-determined nuclear antigen (EBNA) was purified from a variety of EBV-carrying nonproducer cells. Antigen was detected by Western blotting and subsequent visualization of complexes with antiserum/protein A. All cell lines contained several EBNA components, ranging in molecular weight from 48,000 (48K) to 73K. Even higher-molecular-weight forms of EBNA-positive immunoreactivity were detected, but in much lower yield and in only some preparations (8IK in Raji; 120K in Namalva and Raji). Preparations in which the 48K, 65K, 70K, or 73K polypeptides predominated had amino acid compositions with largely similar distributions for most residues. The preparations also yielded similarly sized large fragments upon proteolytic treatments. These findings suggested that all structures are related and that the 48K component may be a part of, or a degradation product from, the larger 65–73K component

ISSN:0300-5526    

DOI:10.1159/000149394

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

The ultrastructural aspects of rotavirus SAll infection were studied in MA 104 cells, with particular attention directed to the early stages of virus adsorption and penetration. Within the first few minutes postadsorption, rotavirus was seen at the plasma membrane, associated with coated pits and coated vesicles, indicating that SAll virus is taken into the cell by adsorptive or receptor-mediated endocytosis. Multiple virus particles were seen, beginning at 1 h and continuing throughout infection, in lysosome-like structures. Ultrastructural evidence was obtained to support the hypothesis that rotavirus progeny acquire a temporary envelope by budding into cisternae of the rough endoplasmic reticulum.

ISSN:0300-5526    

DOI:10.1159/000149395

出版商:S. Karger AG    

年代:1983

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000149396

出版商:S. Karger AG    

年代:1983

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000149397

出版商:S. Karger AG    

年代:1983

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000149389

出版商:S. Karger AG    

年代:1983

数据来源: Karger