Biomedical subjects

C H Murphy

Publications and source records attributed to C H Murphy.

3 recordsLinked to original sources

PubMed1987

The effects of cigarette smoking on voice-fundamental frequency.

Previous group research has shown that the mean voice-fundamental frequency (F0) for individuals who smoke is lower than that of age- and sex-matched nonsmokers. It is believed that this reduction in F0 is a result of edema of the vocal folds caused by tobacco smoke. This study investigated F0 changes during smoking and no-smoking periods. Data were collected before, during, and after a 40-hour period of no-smoking. Analysis of the voice recordings showed a rise in voice F0 for the two smoking subjects during the 40-hour no-smoking period. Age- and sex-matched control subjects did not show a rise in their F0 during the same tasks. Results suggest that the pitch-lowering effects of cigarette smoking may be reversed after as few as 40 hours of smoking cessation.

Adult↗

PubMed1985

Whole-breast sonography.

Ultrasound has been found to be useful as an adjunct to mammography and physical examination of the breast. It has detected lesions not identified by any other modality and has allowed more precise diagnosis of palpable and/or radiographically demonstrated lesions. Ultrasound should not be used as the sole breast imaging modality, however, because of its inability to detect microcalcifications and its difficulty in demonstrating small solid lesions, particularly in the fatty breast.

Abscess↗

PubMed1982

Genetic characterization of the glutamate dehydrogenase gene (gdhA) of Salmonella typhimurium.

Salmonella typhimurium mutants, either devoid or glutamate dehydrogenase activity or having a thermolabile glutamate dehydrogenase protein, were used to identify the structural gene (gdhA) for this enzyme. Transductions showed that the mutations producing these phenotypes were linked to both the pncA and nit genes, placing the gdhA locus between 23 and 30 U on the S. typhimurium chromosome. Additional transductions with several Tn10 insertions established the gene order as pncA-gdhA-nit. Since few genetic markers exist in this region of the chromosome, Hfr strains were constructed to orient the pncA-gdhA-nit cluster with outside genes. Conjugation experiments provided evidence for the gene order pyrD-pncA-gdhA-nit-trp. To further characterize gdhA, we used Mu cts d1 (Apr lac) insertions in this gene to select numerous strains containing deletions with various endpoints. Transductions of these deletions with strains containing different gdh mutations and with a mutant having a thermolabile glutamate dehydrogenase protein permitted us to construct a deletion map of the gdhA region.

Chromosome Mapping↗