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Biomedical subjects

P T Gammon

Publications and source records attributed to P T Gammon.

At least 19 recordsLinked to original sources
PubMed1977

Acetylator phenotyping of tuberculosis patients using matrix isoniazid or sulphadimidine and its prognostic significance for treatment with several intermittent isoniazid-containing regimens.

1. The acetylator phenotype of over 600 pulmonary tuberculosis patients treated with intermittent isoniazid-containing regimens in two controlled clinical trials was determined using either sulphadimidine or a slow-release isoniazid formulation. 2. Both methods unequivocally classified over 99% of the patients as being either slow or rapid acetylators. 3. Rapid and slow acetylation did not differ in their ability of hydrolyse acetylisoniazid to isonicotonic acid plus monoacetylhydrazine, or to conjugate isonicotinic acid with glycine. 4. Rapid acetylators acetylated the monoacetylhydrazine liberated in vivo more rapidly than slow acetylators, demonstrating that this compound is also polymorphologically acetylated in man. 5. The acetylator phenotype of the patients was without prognostic significance when they were treated on a twice-weekly basis with isoniazid plus streptomycin plus pyraziniamide, or with isoniazid plus rifampicin. However, when patients were treated once every week for 12 months with isoniazid plus rifampicin, 5% of the rapid acetylators had an unsatisfactory response as contrasted to the complete success of the treatment in the slow acetylators.

Acetylation↗
PubMed1975

Determination of the acetylator phenotype in a Northern Nigerian population.

The sulphadimidine method was used to determine the acetylator phenotype in tuberculosis patients and hospital workers at Ahmadu Bello University Hospital, Zaria, Nigeria. The method gave good discrimination between slow and rapid acetylators. The proportion of slow acetylators in the whole group was 49 per cent and this is similar to other results from Negro populations.

Acetylation↗
PubMed1975

Determination of the acetylator phenotype using matrix isoniazid.

The development of a simple method for classifying subjects as slow or rapid acetylators is reported. The method is based on determining the ratio of acetylisoniazid to acid-labile isoniazid in the urine 23-24 hours after an oral dose of a slow-release isoniazid formulation. The results obtained when this method was applied to phenotype over 200 East African tuberculosis patients are described. It is suggested that the method would be particularly suitable for classifying tuberculosis out-patients.

Acetylation↗
PubMed1975

The use of isoniazid as a marker to monitor the self-administration of medicaments.

1. Isoniazid was used as a marker to monitor the regularity of drug self-administration in a trial of chemoprophylaxis against natural influenza infection. Two hundred and sixty-two volunteers were treated for five weeks with a synthetic isoquinoline compound (U.K. 2371) or a matching placebo. 2. Five marker tablets containing isoniazid (150 mg) were incorporated into each regimen and their ingestion monitored by testing for acetylisoniazid in the urine. 3. Positive evidence of marker tablet consumption was obtained on 75% of the occasions on which urine samples were requested. The results obtained among the volunteers from each treatment group who returned urine specimens as requested (92%) indicated that they had swallowed at least 81% of their prescribed tablets. 4. The findings of the study suggest that when used in this way isoniazid is a very suitable compound for use on a few occasions for monitoring the self-administration of drugs in clinical trials.

Adolescent↗
PubMed1975

The penetration of dapsone, rifampicin, isoniazid and pyrazinamide into peripheral nerves.

1 Dapsone, rifampicin, isoniazid and pyrazinamide were shown to penetrate readily into the sciatic nerves of the dog and sheep. 2 These findings suggest that the continued persistence of viable drug-sensitive leprosy bacilli in the peripheral nerves of patients treated for long periods with either dapsone or rifampicin is not due to inadequate intraneural drug penetration.

Animals↗
PubMed1972

The determination of isoniazid and its metabolites acetylisoniazid, monoacetylhydrazine, diacetylhydrazine, isonicotinic acid and isonicotinylglycine in serum and urine.

1. A solvent system was devised for the extraction of isoniazid and its metabolites acetylisoniazid, monoacetylhydrazine, diacetylhydrazine, isonicotinic acid and isonicotinylglycine from serum and urine. 2. Specific chemical and fluorimetric methods were developed for the determination of the extracted isoniazid and acetylisoniazid, and chemical methods for the determination of monoacetylhydrazine, diacetylhydrazine, isonicotinic acid and isonicotinylglycine. 3. When applied to serum, these methods were capable of measuring concentrations of down to about 0.005mug of isoniazid/ml, 0.05mug of acetylisoniazid/ml, 0.2mug of monoacetylhydrazine/ml, 0.2mug of diacetylhydrazine/ml, 0.02mug of isonicotinic acid/ml and 0.1mug of isonicotinylglycine/ml. 4. In urine, these methods were capable of measuring concentrations of down to about 0.05mug of isoniazid/ml, 0.2mug of acetylisoniazid/ml, 1mug of diacetylhydrazine/ml, 0.1mug of isonicotinic acid/ml and 0.2mug of isonicotinylglycine/ml. 5. The stability of these compounds was studied in serum and urine and a method devised to decrease their decomposition in serum.

Acetates↗