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Biomedical subjects

S Srinivasan

Publications and source records attributed to S Srinivasan.

At least 253 records · Page 14Linked to original sources
PubMed1981

Comparative pharmacokinetics of cefoperazone and cefamandole.

The pharmacokinetics of cefoperazone, a new beta-lactam antibiotic, were studied in normal volunteers and compared with the pharmacokinetics of cefamandole. After a 30-min infusion of 2 g of cefoperazone, the mean serum level was 256 micrograms/ml; at 4 h, the serum level was 20 micrograms/ml, and at 24 h, the level was 1.25 micrograms/ml, compared with levels of cefamandole of 188 micrograms/ml at the end of infusion, 1.8 micrograms/ml at 4 h, and none detected thereafter. The mean half-life of cefoperazone was 1.6 h, compared with 0.7 h for cefamandole. The area under the curve was 356 micrograms/ml per h for cefoperazone, which was three times that for cefamandole. The apparent volume of distribution for cefoperazone was 9.9 liters/1.73 m2 compared with 12.5 liters/1.73 m2 for cefamandole. Serum clearance of cefoperazone was 85 ml/min, and renal clearance was 25 ml/min, compared with a serum clearance of 224 ml/min and a renal clearance of 213 ml/min for cefamandole. Urine levels exceeded 25 micrograms/ml in the first 8 h after injection. Renal recovery of cefoperazone was only 29%.

Adult↗
PubMed1981

Pharmacokinetics of moxalactam and cefazolin compared in normal volunteers.

The pharmacokinetics of moxalactam, a new beta-lactam antibiotic with an unusually broad spectrum of activity, were studied in normal volunteers and compared with the pharmacokinetics of cefazolin. After a 1,000-mg intramuscular injection of moxalactam, a mean peak serum level of 49 +/- 10 micrograms/ml was achieved at 30 to 60 min which was equivalent to the level achieved with 0.5 g of cefazolin. Serum levels of 4.57 +/- 0.63 micrograms/ml, above the inhibitory levels for most organisms, were present at 8 h. The half-life of moxalactam was 2.3 h. After a 30-min intravenous infusion of 1 g, the serum level of moxalactam was 60 +/- 18.8 micrograms/ml. This compares with a serum level of 70 micrograms/ml obtained with an infusion of 0.5 g of cefazolin. At 6 h, 3.59 +/- 0.68 microgram/ml of moxalactam was present. The half-life of moxalactam was 2.3 h, similar to that of cefazolin. By 1 h after administration, serum levels of moxalactam were higher after intramuscular administration than after intravenous delivery. Urinary recovery of the drug was 76% after intramuscular injection and 74% after intravenous infusion, with the majority of the drug having been excreted in the first 4 h after administration. Urinary recovery of cefazolin was 85%. The pharmacokinetics of moxalactam are similar to those of cefazolin.

Adult↗
PubMed1981

Pharmacology of ceftizoxime compared with that of cefamandole.

The pharmacokinetics of ceftizoxime, a new beta-lactam antibiotic, were studied in normal, male volunteers and compared with the pharmacokinetics of cefamandole. After administration of 500 mg intramuscularly, ceftizoxime produced a peak level of 13.7 +/- 1 microgram/ml, compared with 13.2 +/- 1.6 microgram/ml for cefamandole. At 4 h, the serum level of ceftizoxime was 4.8 micrograms/ml, and that of cefamandole was 1.9 microgram/ml. At 8 h, ceftizoxime was still detected at 0.73 microgram/ml, whereas cefamandole was not. The half-life of ceftizoxime after intramuscular administration was 1.7 h, compared with 1 h for cefamandole. Serum levels of ceftizoxime and cefamandole after 1 g infused over 30 min were 84 and 88 micrograms/ml, respectively. At 5 h cefamandole was not detectable, whereas ceftizoxime had a serum level of 4.5 micrograms/ml and, at 7 h, 2.1 micrograms/ml. The half-life of ceftizoxime was 1.9 h, compared with 0.78 h for cefamandole. Urinary recovery of ceftizoxime after intramuscular and intravenous administration was 70 and 80%, respectively, compared with 78 and 73% for cefamandole.

Adult↗
PubMed1981

Pharmacokinetics of moxalactam in patients with renal failure and during hemodialysis.

The pharmacokinetics of moxalactam were determined in eight patients with end stage renal disease who were undergoing chronic hemodialysis. The mean half-life of moxalactam in the interdialysis period was 19 h, with a range of 9 to 30 h. The mean half-life of moxalactam during dialysis was 4 +/- 0.58 h. Serum levels of 30 +/- 10 micrograms/ml were present 24 h after a 1-g dose in the interdialysis period. A dose of 1 g at the end of each dialysis period in patients undergoing thrice-weekly hemodialysis would provide levels far in excess of the minimal inhibitory levels against Enterobacteriaceae.

Adult↗
PubMed1981

Rapid, reproducible enzyme immunoassay for tobramycin.

An enzyme immunoassay for tobramycin utilizing glucose 6-phosphate dehydrogenase was compared with the radioimmunoassay. The enzyme immunoassay for tobramycin was accurate, specific, and easily performed. It offers an alternative method for assaying aminoglycosides and could be used in institutions that use the enzyme immunoassay to assay other drugs.

Anti-Bacterial Agents↗
PubMed1980

Nosocomial multiply resistant Providencia stuartii: a long-term outbreak with multiple biotypes and serotypes at one hospital.

A long-term outbreak of urinary tract-associated multiply resistant Providencia stuartii occurred in a large medical facility that included a 513-bed chronic care unit. The unique characteristics of this outbreak were that from within a single medical facility, P. stuartii with multiple serotypes, biotypes, and antibiograms could be identified. The organisms isolated had five different biotypes, seven different antibiograms, and two major serotypes. All of the organisms were susceptible to amikacin, cefamandole, and cefoxitin. Application of standard infection control measures impeded the spread of this outbreak, and it slowly terminated 16 months later.

Anti-Bacterial Agents↗
PubMed1979

Influence of a few coat protein subunits on the base-paired structure of 3'-terminal fragments of RNA 4 of alfalfa mosaic virus.

In contrast to expectation (Srinivasan, S. and Jaspars, E.M.J. (1978) Biochim. Biophys. Acta 520, 237-241) differentiated thermal melting profiles and fluorescence measurements show that the coat protein of alfalfa mosaic virus has a negligible effect on the base-paired structure of isolated 3'-terminal fragments (length about 90 nucleotides) of the coat protein messenger RNA (RNA 4) of this virus.

Ethidium↗
PubMed1978

Influence of a few coat protein subunits on the base-paired structure of the RNA species of alfalfa mosaic virus.

Differentiated thermal melting profiles were made of all the three RNA species (RNAs 1, 2 and 3), constituting the genome of alfalfa mosaic virus and of the subgenomic coat protein messenger RNA (RNA 4) of this virus. Whereas all profiles showed multiphasicity the profile of RNA 4 was most clearly subdivided showing three clear transitions with tm values of 25.5, 35.5 and 53 degrees C. The first transition disappeared upon addition of 6 coat protein molecules per molecule of RNA 4. The effect of coat protein on the melting profiles of the genome RNAs was much less clear.

Capsid↗
PubMed1976

Inbreeding among some Brahman populations of Tamil Nadu.

A statewide survey of four endogamous Brahman populations of Tamil Nadu reveals a low level of inbreeding in three of them. In the fourth population, the Thengalai, the level is higher, but not as high as in other social castes. The Tamil Brahmans rank next to the Telugu and the Kanarese Brahmans in this respect. Uncle-niece marriages also occur as in Telugu-speaking populations, and these exceed in the two Ayyangar populations in comparison to the Ayyar. A decline of first-cousin marriages and an increase of uncle-niece marriages are detected in the first two living generations in each population.

Consanguinity↗
PubMed1975

Thromboresistance of glass after glow discharge treatment in argon.

Glow discharge treated (GDT) inorganic materials are sterile and free of all organic contaminants. Such materials implanted in the canine inferior vena cava often demonstrate significant thromboresistance. Standard Pyrex glass tubing was GDT in argon to provide a surface free energy above 70 dynes/cm, slight surface negativity, and other surface-physical modifications of its interface. Chromic acid cleaned lengths of the same tubing, and short segments whose edges were not fire-polished were used as controls. Upon canine implantation, the in vivo results were similar in independent surgical laboratories. The glass was implanted as 1.4 cm long rings or as 5 cm long tubes in separate medical centers according to different protocols. GDT specimens remained patent; all controls accumulated thrombi. A remarkably pure, low critical surface tension, labile protein coating covered all cylindrical lumens after 2 hr in vivo. This coating diminished within 2 weeks and was essentially absent after 480 days, eeven though scanning EM showed evidence of a micron thick luminal film, probably eroding glass. No emboli were found in the implant animal's kidney or lungs at any stage.

Animals↗