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Biomedical subjects

A J Hackett

Publications and source records attributed to A J Hackett.

At least 73 records · Page 4Linked to original sources
PubMed1974

The specificity of dimethylbenzylrifampicin as an inhibitor of viral induced transformation.

The effect of 2',6'-dimethyl-N(4')-benzyl-N(4')- [desmethyl]rifampicin on viral transformation induced by two unrelated oncogenic viruses was compared. Transformation of Balb/3T3 cells by the small, DNA-containing papova virus simian virus 40 was completely normal under conditions where transformation by the large, RNA-containing oncornavirus murine sarcoma virus was inhibited more than 150-fold. For these experiments a resistant variant of Balb/3T3 was selected that grows well in high concentrations of the drug, is not dependent on the drug for growth, and is probably not blocked at the level of drug uptake. These data show that dimethyl-benzylrifampicin specifically inhibits oncornavirus-induced transformation rather than nonspecifically inhibiting cellular growth or transformation.

Animals↗
PubMed1973

Infectivity and RNA patterns as functions of high- and low-dilution passage of murine sarcoma-leukemia virus: evidence for autointerference within an oncornavirus population.

Heterogeneity of buoyant density and RNA content of virions of Moloney murine leukemia-sarcoma complex [MSV (MLV)] was the result of passage at low dilution. Heterogeneous stocks revealed two major RNA components in the population, with the smaller component, apparent mol wt 4 x 10(6) to 5 x 10(6), becoming predominant upon serial passage at low dilution. Concomitantly, infectivity titers of both MLV and MSV decreased upon serial passage at low dilution. MSV (MLV) passaged at high dilution retained high titers and a rather homogeneous high-molecular-weight RNA population characteristic of high-buoyant-density virions. Interference of both MLV and MSV replication was demonstrated by employing mixed inocula containing both low- and high-dilution passage stocks of MSV (MLV). In contrast to results with MSV (MLV), MLV freed of MSV by limit dilution did not show heterogeneity of buoyant density or of RNA when propagated at low dilution.

Animals↗
PubMed1972

Synergistic effect of rifamycin derivatives and amphotericin B on viral transformation of a murine cell line.

One of the most potent inhibitors of RNA-dependent DNA polymerase activity so far described (rifazacyclo-16) was not correspondingly as active in focus inhibition. This discrepancy was thought to be due to the inability of the drug to penetrate the cell membrane. It has been found that a very low level of amphotericin B allows this drug, as well as the previously described 2',6'-dimethyl-N(4')benzyl-N(4')-[desmethyl] rifampicin, to exhibit a very high capability to inhibit focus formation. Since these two drugs are highly lipophilie, their activity may be expected to be dependent upon any lipophilic components in the medium, such as serum or detergents. The use of amphotericin B as well as serum in tissue cultures is common, and could account for some of the variability in focus inhibition reported in the literature.

Amphotericin B↗