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Biomedical subjects

J M Leonard

Publications and source records attributed to J M Leonard.

66 records · Page 4Linked to original sources

Sulfamethoxazole-trimethoprim-polymyxin therapy of serious multiply drug-resistant Serratia infections.

Nonpigmented multiply drug-resistant Serratia marcescens caused an extensive outbreak of infection at the Nashville Veterans Administration Hospital. Isolates were of one serotype resistant to all currently available antimicrobial agents for therapy of systemic infections except for occasional susceptibility to chloramphenicol and kanamycin. Frequently strains were susceptible to nalidixic acid, and all were susceptible to amikacin (BB-K8). Drug-resistant strains caused 130 infections, 12 bacteremias, and 7 infection-associated deaths. Combinations of antimicrobial agents were evaluated for synergism against Serratia strains from infected patients. "Checkerboard" isobolograms indicated in vitro static synergism between sulfamethoxazole, trimethoprim, and polymyxin (STP). Killing curves using clinically achievable concentrations of STP verified the bactericidal effect of STP against these strains. In a daily dosage of 1,600 mg of sulfamethoxazole and 320 mg of trimethoprim orally in combination with 100 to 300 mg of colistimethate parenterally, serum cidal levels at 1:8 or greater were achieved in five of six patients. Clinical improvement or microbiological cure was effected in four of six patients. STP may be potentially useful for selected Serratia infections for which single agents are unavailable or ineffective.

Clinical Trials as Topic↗

Effect of nitrogen and calorie restriction on protein synthesis in the rat.

The effect of a deficiency of calories and/or nitrogen on protein metabolism in the rat was investigated. During the 5 days of the study, the rats received all nutrients except water via intravenous hyperalimentation. Four diets were used: I) 1.25 g amino acids, 12.5 g glucose/day; II) 1.25 g amino acids/day; III) 1.25 g glucose/day; and IV) 12.5 glucose/day. The rate of protein synthesis in heart, lung, muscle, kidney, and liver was estimated by a modification of the technique of Garlick et al. (The diurnal response of muscles and liver protein synthesis in vivo in meal-fed rats. Biochem. J. 136: 935-945, 1973) except that [15N]glycine was used as the tracer. Heart and lung protein synthesis was depressed by both caloric and nitrogen restriction. Muscle protein synthesis was only significantly affected by omission of calories from the diet. Kidney nitrogen content increased with the amino acid diets and decreased with the nitrogen-deficient diets. The major response of the liver to a dietary deficiency was to lose nitrogen via an increase in the rate of liver protein catabolism.

Animals↗