Search PubMed⌕ Search

Biomedical subjects

A M Harris

Publications and source records attributed to A M Harris.

At least 91 records · Page 5Linked to original sources
PubMed1975

The use of analytical isoelectric focusing for detection and identification of beta-lactamases.

BETA-Lactamases (EC. 3.5.2.6) from strains of Gram-negative bacteria have been studied using analytical isoelectric focusing. This permits a visual comparison of the patterns of beta-lactamase bands produced by enzymes from different organisms. Purification of crude intracellular preparations is unnecessary and the technique is sufficiently sensitive to demonstrate beta-lactamase in mutants previously reported to lack the enzyme. R that have not been distinguished from one another biochemically or immunologically can be differentiated by isoelectric focusing. Conversely, the enzymes specified by the R factors RTEM, R1 and RGN14, with identical isoelectric focusing patterns have the same biochemical properties. Chromosomal and R-factor-mediated beta-lactamases from single strains have been separated and their identities confirmed by immunoisoelectric focusing. R factor-mediated enzymes gave identical isoelectric focusing patterns irrespective of the host strain. Isoelectric focusing can therefore be used to observe the transfer of beta-lactamases carried by R factors.

Amidohydrolases↗
PubMed1975

The treatment of ethylene glycol toxicosis with pyrazole.

Rats and dogs were protected from the effects of lethal doses of ingested ethylene glycol (EG) with pyrazole (P), an inhibitor of liver alcohol dehydrogenase. Rats given 1.35 ml/100 g of EG followed by 2.2 mmol/kg of P i.p. at 6 and 30 hours postingestion survived. Untreated control animals died. Dogs were given either 10.0 or 12.5 ml/kg of EG and treatment was begun 6 hours later. The control treatment consised of NaHC03 administered i.v. according to the calculated base deficit, B-complex vitamins with ascorbic acid, hydrocortisone, and 5 per cent glucose in water. The addition postexposure to this treatment of 0.9 mmol/kg of P and 0.5 mmol/kg of P at 6 and 30 hours, respectively, constituted the experimental therapy. In summary: with 10 ml/kg of EG, no P, 2 of 5 dogs survived; 12.5 ml/kg of EG, no P, 0/1; 10 ml/kg of EG plus P, 9/11; 12.5 ml/kg of EG plus P, 12/22. Dogs that succumbed had large numbers of oxalate crystals in their kidneys at necropsy. The surviving dogs had few oxalate crystals in their kidneys at the time of unilateral nephrectomy (2 weeks postexposure) or necropsy (30 days postexposure). Several clinical factors were identified as useful prognostic indicators in the treatment of EG poisoning. The results suggested that pyrazole, despite its marked toxicity, may be of clinically significant value in the treatment of ethylene glycol poisoning when therapy is initiated withing 6 hours of exposure.

Animals↗
PubMed1972

Dry cow therapy.

Explore the source record for details and available documents.

Animals↗
PubMed1972

Comparison of the substrate specificities of the -lactamases from Klebsiella aerogenes 1082E and Enterobacter cloacae P99.

A potent beta-lactamase (EC 3.5.2.6) produced by a strain of Klebsiella aerogenes (K. pneumoniae), 1082E, isolated from a hospital patient, has been examined. Its properties were different from those of most gram-negative beta-lactamases previously reported. The enzyme has been partly purified, and its activity against a range of substrates has been compared with that of the enzyme from Enterobacter cloacae (Aerobacter cloacae) P99. The K. aerogenes enzyme, although predominantly a penicillinase, had a wide range of specificity. In addition to hydrolyzing the cephalosporins, it attacked the normally beta-lactamaseresistant compounds methicillin and cloxacillin as well as cephalosporin analogues with the same acyl substituents. The results obtained with the E. cloacae enzyme confirmed its cephalosporinase activity and showed that, unlike the enzyme from K. aerogenes, it was relatively inactive against the penicillins.

Ampicillin↗
PubMed1972

Why bother?

Explore the source record for details and available documents.

Occupational Health Nursing↗
PubMed1971

Effect of digoxin on A-V conduction.

The effect of digoxin on A-V conduction in 19 patients with known disease of their conduction tissue was studied while a demand pacing system was in position. Fifteen had transient complete heart block after myocardial infarction and four had chronic intermittent complete heart block. The patients were studied on return to sinus rhythm.In no instance was a return to either second- or third-degree heart block precipitated in these patients despite therapeutic levels and, in some cases, high serum level of digoxin for a period of seven days.The duration of complete heart block after myocardial infarction was 4.3 days in those taking digoxin while in heart block and 3.3 days in those who started digoxin only after return to sinus rhythm.

Aged↗