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Biomedical subjects

A R Bellamy

Publications and source records attributed to A R Bellamy.

At least 73 records · Page 4Linked to original sources
PubMed1976

Modulating effects of interferon preparations on an antibody response in vitro.

The effect of mouse interferon preparations on the primary in vitro antibody response of mouse spleen cells was studied. Concentrations of interferon greater than 8 units per ml significantly inhibited the antibody response while low concentrations of 0-08-0-8 units per ml could be shown to be mildly enhancing. Various treatments which affected the antiviral activity of the interferon preparations reduced the immunosuppressive activity to a similar extent. Interferon acts during the first few hours of a response but the effect is not apparent for at least 50 h. Interferon had no effect when added after 48 h. The kinetic data has been interpreted as demonstrating interferon-sensitive and interferon-resistant components of the in vitro response. The results from investigations of the polyclonal response to lipopolysaccharide support the view that interferon acts mainly on B cells alone, although effects on T-B interactions cannot be excluded.

Animals↗
PubMed1974

Electron microscopy study of reovirus reaction cores.

A combined staining and shadowing method has been used to enhance the contrast of both reovirus cores and the RNA product that they have synthesized. After limited synthesis when all RNA strands associated with the core are nascent, many cores are observed that have more than 10 strands associated with each particle. The lengths of individual nascent mRNA molecules are not identical: many strands are extruded in the form of loops. These observations are consistent with the notion that synthesis of individual mRNA molecules occurs simultaneously at different rates at a number of different sites. The sites of extrusion are probably the 12 hollow projections located on the surface of the core.

Cell-Free System↗
PubMed1974

Molecular weight of two oncornavirus genomes: derivation from particle molecular weights and RNA content.

Sedimentation analysis and intensity fluctuation spectroscopy have been used in conjunction with the Svedberg equation to determine the particle molecular weights of Rous sarcoma virus (Prague strain) and avian myeloblastosis virus (BAI strain). The molecular weights of these two viruses are (294 +/- 20) x 10(6) and (256 +/- 18) x 10(6), respectively. Values for the molecular weight of the RNA contained in each particle have been calculated as (5.58 +/- 0.5) x 10(6) and (5.88 +/- 0.5) x 10(6). Since the proportion of the viral RNA represented by 4 to 7S low-molecular-weight material is known, the molecular weight of the 60 to 70S genomes may be calculated to lie in the range (3.8 +/- 0.3 to 4.8 +/- 0.4) x 10(6) for both particles. These estimates for the molecular weight of the 60 to 70S genome are much lower than previous estimates and fall within the range of current estimates of the size of a single 35S subunit. The implications of this finding are discussed in terms of current theories for the structure of the genome of RNA tumor viruses.

Avian Leukosis Virus↗
PubMed1971

Viral RNA polymerases: electron microscopy of reovirus reaction cores.

The Kleinschmidt technique has been used to observe reovirus cores that have synthesized messenger RNA. Some individual viral cores probably synthesize all ten messenger RNA molecules in vitro. Each messenger RNA molecule appears to be attached to a different site on the core surface, implying that there are probably a number of different enzymic sites in each core.

Adenosine Triphosphate↗
PubMedDate not supplied

Cytomegalovirus myocarditis in a heart transplant recipient: sensitive monitoring of viral DNA by the polymerase chain reaction.

A 54-year-old female heart transplant recipient had an acute episode of graft rejection that was treated with high-dose immunosuppression therapy. During this therapy a second febrile illness developed, which was accompanied by hypotension, anemia, and rash. Findings for subsequent myocardial biopsy specimens were negative for cytomegalovirus by culture but were strongly positive for cytomegalovirus deoxyribonucleic acid by the polymerase chain reaction. Histologic observation of viral inclusions in the myocardial fibers supported the diagnosis of cytomegalovirus myocarditis. The polymerase chain reaction therefore can provide a rapid and highly sensitive method for heart transplant patients with suspected cytomegalovirus myocarditis.

Cytomegalovirus↗