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Biomedical subjects

C H Birge

Publications and source records attributed to C H Birge.

12 recordsLinked to original sources
PubMed1987

Heat-shock proteins induced during the mycelial-to-yeast transitions of strains of Histoplasma capsulatum.

Heat-shock proteins (hsp) were elicited when mycelia of the Downs strain and the more virulent G184A and G222B strains of Histoplasma capsulatum were shifted up to temperatures which induced the mycelial-to-yeast transition (34-40 degrees C). The classes of the major hsp which increased in synthesis in each strain were similar. However, the pattern of synthesis of these proteins at the different temperatures in Downs differed from those in the G184A and G222B strains: hsp synthesis in Downs peaked at 34 degrees C, whereas in G184A and G222B it was highest at 37 degrees C.

Heat-Shock Proteins↗
PubMed1978

Comparison of initiation rates of encephalomyocarditis virus and host protein synthesis in infected cells.

The relative initiation rates for encephalomyocarditis virus mRNA and host mRNA's in infected cells were measured using two independent techniques. In both cases the results showed that viral mRNA initiates at a much higher rate than host mRNA'S. This difference was observed midway in the infectious cycle, well before virus-induced cytopathic effects (leakage of low-molecular-weight metabolites, failure to exclude trypan blue) were apparent. These results confirm that encephalomyocarditis viral mRNA is a more efficient initiator than host mRNA's in vivo, as has previously been demonstrated in in vitro experiments.

Animals↗
PubMed1978

Specificity of interferon action in protein synthesis.

Inhibitors of elongation steps in protein synthesis such as cycloheximide and anisomycin mimic interferon treatment in that they specifically inhibit the synthesis of certain viral proteins. These specific effects are seen only at very low concentrations of the antibiotics, under conditions where host cellular protein synthesis, as well as cell viability, are not severely reduced. A qualitatively as well as quantitatively close correlation between the effects of the two types of agents has been established for encephalomyocarditis virus, vesicular stomatitis virus and murine leukemia virus protein synthesis. It is concluded that one of the primary mechanisms of interferon action may be a nonspecific retardation of one or more elongation steps, and that this may be sufficient to account for its effects on the replication of certain viruses such as encephalomyocarditis and vesicular stomatitis viruses.

Anisomycin↗
PubMed1976

Competition between cellular and viral mRNAs in vitro is regulated by a messenger discriminatory initiation factor.

Encephalomyocarditis viral RNA has previously been shown to outcompete host cellular mRNA has for translation in vitro in crude and fractionated protein synthesizing systems. In the present communication it is shown that the competition is regulated by an initiation factor or complex of factors, and not the 40S initiation complex per se. The factor primarily involved is the murine equivalent of a component present in a partially purified preparation of rabbit initiation factor M3. Both the murine and rabbit factors are clearly messenger discriminatory.

Animals↗
PubMed1970

Enzyme specificity as a factor in regulation of fatty acid chain length in Escherichia coli.

Various acyl-acyl carrier protein intermediates in saturated and unsaturated fatty acid biosynthesis were tested as substrates for beta-ketoacyl-acyl carrier protein synthetase. With both classes of substrates the condensing enzyme in fatty biosynthesis demonstrates specificities which indicate that it might be an important factor in determining fatty acid chain length in Escherichia coli.

Acyltransferases↗
PubMed1969

Evidence for two genes specifically involved in unsaturated fatty acid biosynthesis in Escherichia coli.

Unsaturated fatty acid auxotrophs of Eschericha coli have been divided into two distinct cistrons by extract complementation and genetic complementation based on abortive transduction. Lesions in one cistron result in the loss of the beta-hydroxydecanoyl thioester dehydrase which produces the first biosynthetic intermediate in unsaturated fatty acid formation. Evidence is presented which indicates that lesions in the second cistron result in the lack of a second enzyme specifically involved in the biosynthesis of unsaturated fatty acids.

Carbon Isotopes↗