摘要:

Serial undiluted passage of clonally purified herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in 4 different types of cells resulted in (i) partial loss (84–98%) of infectivity and (ii) the appearance of a new DNA within the infected cells with a higher buoyant density in CsCl (p = 1.732 g/cm3) than that of HSV-1 (1.725 g per cm3) or that of HSV-2DNA (1.727 g/cm3). Serial diluted passages of these stocks restored the high infectivity titers with a concomitant loss of the high density DNA within the infected cells. Serologic studies and electron microscopy indicated that the HSV stocks were not contaminated with an extraneous virus which might yield a DNA with the high buoyant density. Characterization of purified HSV from the serially passed undiluted stocks indicates that the high density DNA is a part of the HSV virion replicating under these conditions. The results obtained suggest the production of defective interfering particles after undiluted passage of HS

ISSN:0300-5526    

DOI:10.1159/000148841

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Cultures of hamster embryo fibroblasts originally trans formed in vitro by herpes simplex virus (HSV) type 2 previously irradiated with ultraviolet light were resistant to superinfection by HSV-1 and HSV-2. The degree of resistance was dependent upon the concentration of the superinfecting virus. At an MOI of 1.0 infectious virus particle per cell, significant virus replication occurred. At an MOI of 0.001 per cell, little or no virus replication was detected. In normal hamster embryo fibroblasts, virus replicated when either high or low MOI were used. Early events in the virus-replicative cycle were found to proceed normally. The results suggest that HSV can initiate and complete the infectious cycle in a limited number of herpes-transformed cells, a finding similar to that observed for Epstein-Barr herpesvirus systems.

ISSN:0300-5526    

DOI:10.1159/000148842

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The in vitro transcriptase activities of B particles and three types of T particles of vesicular stomatitis virus were measured and compared. All three types of T particles were transcriptase-positive and were more active per unit mass of protein than B particles. Analysis of the RNA products synthesized in vitro showed in each instance template-associated material as well as free single-stranded RNA species.

ISSN:0300-5526    

DOI:10.1159/000148843

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The control of murine sarcoma virus (MSV) genetic information in rat cells transformed by a mutant was examined. Expression of the Cold-sensitive MSV transformed phenotype by cells after shift from the non permissive (33°) to the permissive temperature (39°) was not prevented by inhibitors of DNA and RNA synthesis but was prevented by inhibitors of protein and glycoprotein synthesis. Similar amounts of viral-specific RNA, measured by RNA-DNA hybridization, were found in cells grown at the permissive or nonpermissive temperature. The results suggest that the expression of transformation involves translational and possibly post-translational, but not transcriptional contro

ISSN:0300-5526    

DOI:10.1159/000148844

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The serological and biological properties of the two antigenically identical lines of the prototype CHHE-29 strain of echovirus 17 were compared. One (Kansas line) had been passaged only in cultures of rhesus monkey kidney (RhMK) cells and the other (Baylor line) in cultures of RhMK and African green monkey kidney (GMK) cells. The former was less sensitive to antibody and insensitive to agar inhibitor, and grew well in cultures of cynomolgus monkey kidney (CyMK) cells but less rapidly in GMK cultures, while the latter was more sensitive to antibody and sensitive to agar inhibitor, and grew well in either CyMK or GMK cultures. Six local strains of virus were similar to the Kansas line and were unchanged by passages in CyMK cultures. The selection imposed by serial passages of these viruses through GMK cultures, however, suggested that virus of the Baylor line may be derived from a mutation or be a selected subpopulation of the original virus of the CHHE-29 strain.

ISSN:0300-5526    

DOI:10.1159/000148845

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

A method was developed for detection of group A arboviruses, Sindbis and Venezuelan equine encephalomyelitis (VEE), in the salivary glands of experimentally infected Aedes aegypti mosquitoes by direct immunofluorescence with counter staining. During the period shortly after infection, the virus was localized in distal parts of the lateral lobules of the salivary glands, whereas during the time of maximum multiplication it was concentrated in the anterior parts. Detection of the virus in the salivary glands by immunofluorescent staining techniques reflected the ability of the mosquito to transmit infection by bite.

ISSN:0300-5526    

DOI:10.1159/000148846

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Different components of brome mosaic virus (BMV) RNA, either separate or mixed, stimulated similarly the activity of soluble BMV-RNA polymerase. When unfractionated RNA was heated, the various components disappeared in order of molecular size (the largest fastest), and the infectivity remaining depended on the concentration of the three largest components. The enzyme-stimulating activity, however, decreased more slowly and was still 40% of that of unheated RNA when only the small BMV-RNA component (0.28 × 106 daltons) remained partly undegraded. We suggest reasons why each component of BMV-RNA can serve as template, yet in the complete mixture the smallest appears by far the most active

ISSN:0300-5526    

DOI:10.1159/000148847

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Two virus isolates from California sea lions and one from an Alaskan fur seal, classified as caliciviruses based on their relationship to vesicular exanthema of swine virus, were examined for biochemical and biophysical properties. They all had a buoyant density of 1.37 g/ml in CsCl; one showed some heterogeneity in CsCl. The sedimentation rate in 5–20% sucrose was 183S for all three. Crystals were obtained from one of the viral preparations. RNA, but no DNA, was present inall three. The molecular weight of the genome was probably 2.6 × 106 daltons, and the particle mass probably 12 × 106 dalt

ISSN:0300-5526    

DOI:10.1159/000148848

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Doses of puromycin or cycloheximide which prevent morphological transformation, following a temperature shift from 41 to 37°, of chick embryo cells infected with the ts mutant FU 19 of SR-RSV (D) do not prevent the increase of cell agglutinability by concanavalin A which normally parallels transformation. Hence, cell transformation and agglutinability may depend on the expression of distinct viral information; or, alternatively, they could depend on different levels of expression of the same information

ISSN:0300-5526    

DOI:10.1159/000148849

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The total carbohydrate content of purified hepatitis B antigen (HB Ag) ranged between 3.6 and 6.5% as determined by the phenol-sulfuric acid method. Disc-sodium dodecyl sulfate PAGE of purified HB Ag followed by periodate-Schiff staining revealed one major and two minor glycoproteins with molecular weights of 22,000,27,000 and 32,000 daltons, respectively. Both ad and ay subtypes of HB Ag contained these glycoproteins.

ISSN:0300-5526    

DOI:10.1159/000148850

出版商:S. Karger AG    

年代:1973

数据来源: Karger