摘要:

Treatment of hepatitis B surface antigen (HBsAg) with either chloroform-methanol (2:1, v/v) or 50% l,Γ,3,3’-tetramethylurea did not affect the morphological integrity of the particles (about 20 nm in diameter), although the major portion of lipids was released as indicated by their increased buoyant density in CsCl (1.27 g/cm3 as compared with 1.20 g/cm3 for intact HBsAg). The antigenicity and polypeptide composition of HBsAg was not altered by delipidation. The carbohydrate chains of HBsAg contain penultimate β-D-galactosyl residues. HBsAg was cleaved by chymotrypsin into fragments which were smaller than intact HBsAg by two orders of magnitude and which contained both the a and d determina

ISSN:0300-5526    

DOI:10.1159/000148989

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

Successful transfection of Brown Leghorn chicken fibroblasts was carried out with DNA isolated from duck cells transformed by the LA334 mutant of avian sarcoma virus B77. Transfection of duck cells was negative. The four viruses recovered after transfection were all temperature-sensitive for transformation. Two were fully temperature-sensitive for replication, as shown by analysis of virus replication, by characterization of virus particles produced at the nonpermissive temperature using density gradient centrifugation, and by electron microscopic examination. The other two viruses were only partially temperature-sensitive for replication. The results suggest that both the src and gag regions of the avian sarcoma virus genome are transferred simultaneously during transfection, probably by a single integral provirus copy.

ISSN:0300-5526    

DOI:10.1159/000148990

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

New ultrastructural findings within the nucleus of herpes simplex virus-infected cells are illustrated. The occurrence of bundles of tightly packed filaments during the late stages of the infectious process is described. These bundles were found in different areas of the nucleus and were not associated with any nuclear organelles. Employing different staining techniques and high-resolution autoradiography, they could be identified as DNA-containing nucleoproteins. These filaments may be interpreted as a special form of viral DNA accumulation within the nucleus. Changes of these structures toward a more recticular arrangement were observed as soon as the nucleoplasm disintegrated.

ISSN:0300-5526    

DOI:10.1159/000148991

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

Hepatitis A virus was purified from fecal specimens obtained from 2 patients with naturally acquired hepatitis A. The purification procedure involved differential centrifugation, organic solvent extraction, agarose gel filtration, ion-exchange chromatography, and isopycnic ultracentrifugation in cesium chloride. Using immune electron microscopy and discontinuous SDS-PAGE, this procedure was found to be effective in removing extraneous material from hepatitis A virus. There was significant recovery of virus as judged by immune electron microscopy and solid-phase radioimmunoassay. Using this protocol, it has been possible to obtain virus preparations of sufficient purity and high enough titer to enable biochemical studies to proceed.

ISSN:0300-5526    

DOI:10.1159/000148992

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

A persistent infection by a baculovirus-like particle was found in the established lepidopteran (Heliothis zea) cell line, IMC-HZ-1. The virus caused CPE in less than 1% of the IMC-HZ-1 cells, as measured by phase-contrast and electron microscopy. Transmission tests showed that four lepidopteran cell lines were susceptible to the persistent virus (designated as IMC-HZ-1-NOV). In inoculated TN-368 cell cultures, 90–100% infection was achieved. The ultrastructure and development of IMC-HZ-1-NOV in cell cultures were similar to known baculoviruses, and it is probable that this persistent virus is a member of the family Baculoviridae. Two lepidopterous species (Estigmene acrea and H. zea) inoculated with IMC-HZ-1-NOV by intrahemocoelic injection and/’orper os feeding of larvae were not suscepti

ISSN:0300-5526    

DOI:10.1159/000148993

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

The presence of spontaneously disrupted cytomegalovirus capsíds has made it possible to visualize a subunit within the herpesvirus capsomere. The pattern resolved agreed well with the theoretical net based on the concept of a structural subunit at each apex of the hexon

ISSN:0300-5526    

DOI:10.1159/000148994

出版商:S. Karger AG    

年代:1978

数据来源: Karger