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Biomedical subjects

G J Stanton

Publications and source records attributed to G J Stanton.

At least 73 records · Page 4Linked to original sources
PubMed1978

The role of interferon in virus infections and antibody formation.

Virus-type interferon is capable of suppressing the antibody response both in vivo and in vitro. Interferon induced by antigen or mitogen (immune interferon), primarily in T-lymphocytes, also appears capable of suppressing the antibody response. Cyclic AMP has a regulatory effect on the induction of both virus-type and immune interferon. The immunosuppressive effects of virus-type and immune interferon may differ at the cellular or subcellular level.

Animals↗
PubMed1977

Stimulation of synthesis of the proteins of 30-S nuclear ribonucleoprotein particles in human amnion U cells by viral infection.

Early increase in RNA synthesis induced in human amnion U cells by infection with poliovirus is accompanied by an increased incorporation of amino acids into non-histone nuclear proteins with an approximate molecular weight of 40 000. These proteins are the main polypeptides of the 30-S nuclear ribonucleoprotein particles. After fractionation of nuclear proteins by extraction with solutions of different ionic strength, these polypeptides are present in the fraction of nuclear sap proteins soluble in 0.1 M Tris - HCl buffer, pH 7.6, and in the fraction of non-histone chromosomal proteins which are soluble in 0.35 M NaCl. The increase in synthesis of non-histone nuclear proteins with an approximate molecular weight of 40 000, observed in the infected cells, represents an increase in the synthesis of proteins concerned with post-transcriptional events and, therefore, is the result and not the cause of gene activation.

Carbon Radioisotopes↗
PubMed1977

Effect of interferon, elevated temperature, and cell type on replication of acute hemorrhagic conjunctivitis viruses.

Five strains of enterovirus type 70 (E 70) and four of coxsackievirus type A 24 (CA 24) were studied for their sensitivity to interferon (IF), ability to induce IF, replication at various temperatures, and adaptability to human and mouse cell cultures. We found that isolates ranged from 0.01 to 16 times as sensitive to fibroblast IF as vesicular stomatitis virus, depending upon the cell type used and the multiplicity of infection. Most of the isolates induced no detectable IF; however, when induction occurred the titers were relatively low (5 to 300 U). Only E 70 virus isolates were adaptable to growth in L-cells. Replication of all viruses was inhibited approximately 90% at 37 to 39 degrees C depending upon the cell type. These results and the accessibility of the eye to application of IF and/or heat suggests the possibility of their use for treatment. The adaptation of certain E 70 viruses to mouse L-cells opens the possibility of development of a mouse model infection.

Cell Line↗
PubMed1977

Variables affecting viral plaque formation in microculture plaque assays using homologous antibody in a liquid overlay.

A liquid antibody microculture plaque assay and the variables that govern its effectiveness are described. The assay is based on the principle that low concentrations of homologous antibody can inhibit secondary plaque formation without inhibiting formation of primary plaques. Thus, clear plaques that followed a linear dose response were produced. The assay was found to be more rapid, less cumbersome, and less expensive than assays using agar overlays and larger tissue culture plates. It was reproducible, quantitative, and had about the same sensitivity as the agar overlay technique in measuring infectious coxsackievirus type B-3. It was more sensitive in assaying adenovirus type 3 and Western equine encephalomyelitis, vesicular stomatitis, Semliki forest, Sendai, Sindbis, and Newcastle disease viruses than were liquid, carboxymethylcellulose, and methylcellulose microculture plaque assays. The variables influencing sensitivity and accuracy, as determined by using coxsackievirus type B-3, were: (i) the inoculum volume of virus; (ii) the incubation period of virus; and (iii) the incubation temperature.

Adenoviruses, Human↗
PubMed1976

Diffusible viral interference during arbovirus plaque formation.

A radially diffusing zone of nonspecific interference was observed surrounding plaques of Western equine encephalitis virus. The increase in diameters of the zones of interference were linear and more rapid than increases in plaque diameters. These observations raise the possibility that viral-induced interference could account for the diminished growth of Western equine encephalitis virus plaques with time or even the initial formation of plaques. In addition, this system could be used as a model to study localized host defenses during early infection of solid tissues in vivo.

Encephalitis Virus, Western Equine↗
PubMed1976

Vesicular stomatitis virus plaque production in monolayer cultures with liquid overlay medium: description and adaptation to a one-day, human interferon-plaque.

Vesicular stomatitis virus forms discrete, microscopic plaques in stationary cultures of the WISH amnion cell line. Microplaque formation is rapid, reproducible, and easily quantitated, occurs at temperatures ranging from 33 to 40 degrees C, and does not require a semisolid overlay. WISH cells, however, are less sensitive to vesicular stomatitis virus than are chicken embryo, 3T6, or Vero cells. WISH amnion cells also are highly sensitive to the antiviral effects of human interferon, and a quantitative human interferon assay, based on vesicular stomatitis virus plaque reduction in WISH cells, is described. This interferon assay can be performed within 1 day, uses a liquid overlay medium, does not require a vital stain, is as sensitive as other methods that use diploid cell strains, and is performed in a microtiter system.

Cell Line↗
PubMed1974

Enhanced detection of Western equine encephalitis virus plaque variants in crowded cultures and plaque progeny--potential use in genetic studies.

Enhanced detection of large-plaque variants of Western equine encephalitis virus in the presence of large numbers of small-plaque Western encephalitis virus was achieved by using higher bicarbonate concentrations in the agar-overlay medium and increasing concentrations of CO(2) in an enclosed environment during the time plaques were developed with neutral red. By this technique we were able to detect large-plaque mutants in cloned small-plaque suspensions for the first time and to show an increase in detectable plaque progeny in plaques developed by neutral red. Further increase in the number of progeny per plaque was determined by assaying extracts of agar overlaying cultures containing known numbers of plaques. The significance of these findings for potential use in mutational studies is discussed.

Agar↗
PubMedDate not supplied

Induction of interferon by bacteria, protozoa, and viruses: defensive role.

Interferon is established as one of the natural defenses against virus infection. The evidence that interferon may serve a defensive role against certain protozoa is less complete and consists mainly of induction of interferon during protozoal infection, as well as interferon protection of mice against malarial infection. The evidence that interferon may function as a defense against certain bacterial infections is extended with data indicating that a wide variety of bacteria can induce interferon in the mouse and in cultured human peripheral lymphoid cells. This induction of interferon by bacteria and the ability of interferon under many conditions to activate neutrophils and macrophages raises the possibility that interferon may serve a defensive role against some bacteria.

Animals↗
PubMedDate not supplied

Transmission of IFN-induced activities by cell to cell communication.

In conclusion, many of the activities of IFN are transmissible between cells and may involve more than one transfer mechanism. These mechanisms probably involve secondary messenger molecules which are shared with hormones and act at the transcriptional level. The transfer system seems to be a major amplification process for IFN action. It will be interesting in the future to determine the spectra of IFN activities which are transferable as well as the processes involved.

Animals↗