Search PubMed⌕ Search

Biomedical subjects

R R Martin

Publications and source records attributed to R R Martin.

At least 199 records · Page 11Linked to original sources
PubMed1975

Leptospirosis: an underdiagnosed cause of acute febrile illness.

Two cases of leptospirosis diagnosed at the Texas Medical Center in a two-week period are presented. Most cases of leptospirosis go undiagnosed because the symptoms and signs are nonspecific. Leptospirosis should enter the differential diagnosis when symptoms of influenzal illness, aseptic meningitis, and viral gastroenteritis occur, especially if abnormal hepatic and renal function are shown to be present. Many, but by no means all, patients will give history of exposure to livestock or rodents. Diagnosis is best made by serologic methods; Treatment is usually not required since the disease is self-limited, and even in the more severe form, antibiotics have not been conclusively shown to be of benefit.

Acute Disease↗
PubMed1974

Amikacin (BB-K8) treatment of multiple-drug resistant Proteus infections.

The new aminoglycoside antibiotic, amikacin (formerly called BB-K8), was used to treat 12 episodes of urinary tract infection caused by hospital-acquired Proteus rettgeri strains. These bacteria were resistant in vitro to kanamycin and gentamicin, and infection persisted in most of the patients in spite of therapy with one of these agents. In all cases, the urinary tract infection was controlled or eradicated by therapy, although relapse or reinfection was frequently encountered in these patients with complicated urological problems. No toxicities attributable to the drug were encountered in the small group of patients.

Adult↗
PubMed1973

In vitro migration of human alveolar macrophages: effects of cigarette smoking.

The responsiveness of alveolar macrophages lavaged from healthy volunteers to migration inhibitory factor (MIF) was tested by using the capillary-tube assay method. In every instance, macrophages from nonsmokers responded to MIF as demonstrated by a depression in migration of at least 30%, whereas MIF did not inhibit migration of macrophages from smokers. Cells from smokers migrated at a rate three times faster than cells from nonsmokers. Migration of macrophages from nonsmokers with delayed hypersensitivity skin reactions to Candida albicans antigen was inhibited when antigen was present in the tissue culture medium. Antigen did not inhibit macrophages from subjects who lacked delayed hypersensitivity to the antigen, or from subjects who were cigarette smokers. Since alveolar macrophages can respond to MIF in vitro, they may play a role in cell-mediated immune reactions in the lung. Cigarette smoking may interfere with this participation.

Adult↗
PubMed1973

Common enzymes of branched-chain amino acid catabolism in Pseudomonas putida.

Two types of Pseudomonas putida PpG2 mutants which were unable to degrade branched-chain amino acids were isolated after mutagenesis and selection for ability to grow on succinate, but not valine, as a sole source of carbon. These isolates were characterized by growth on the three branched-chain amino acids (valine, isoleucine, and leucine), on the corresponding branched-chain keto acids (2-ketoisovalerate, 2-keto-3-methylvalerate, and 2-ketoisocaproate), and on other selected intermediates as carbon sources, and by their enzymatic composition. One group of mutants lost 2-ketoisovalerate-inducible branched-chain keto acid dehydrogenase that was active on all three keto acids. There was also a concomitant loss of ability to grow on all three branched-chain amino acids as well as on all three corresponding keto acids, but there was retention of ability to use subsequent intermediates in the catabolism of branched-chain amino acids. Another type of mutant showed a marked reduction in branched-chain amino acid transaminase activity and grew poorly at the expense of all three amino acids, but it utilized subsequent intermediates as carbon sources. Both the transaminase and branched-chain keto acid dehydrogenase mutants retained the ability to degrade camphor. These findings are consistent with the view that branched-chain amino acid transaminase and branched-chain keto acid dehydrogenase are common enzymes in the catabolism of valine, isoleucine, and leucine.

Alcohol Oxidoreductases↗
PubMed1973

Induction of aryl hydrocarbon hydroxylase in human pulmonary alveolar macrophages by cigarette smoking.

Pulmonary alveolar macrophages were obtained from healthy volunteers by saline pulmonary lavage, and aryl hydrocarbon hydroxylase was measured in the cells. Enzyme activity was low in cells from five nonsmokers with a mean of 0.008+/-0.004 U/10(6) cells. Cells obtained from nine cigarette smokers contained higher enzyme levels, with a mean of 0.095+/-0.024 U/10(6) cells. A former cigarette smoker was lavaged on five occasions. Enzyme activity during two lavages 4 mo apart were 0.010 and 0.009 U/10(6) cells, respectively. 1 wk after smoking was resumed, the enzyme activity rose slightly to 0.013, and reached 0.041 U/10(6) cells by 1 mo. Upon cessation of smoking, the enzyme activity returned to control levels by the next lavage, 2 mo later. These data indicate that aryl hydrocarbon hydroxylase may be induced in pulmonary alveolar macrophages of subjects chronically exposed to cigarette smoke.

Adolescent↗