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Biomedical subjects

M Atef

Publications and source records attributed to M Atef.

52 records · Page 3Linked to original sources
PubMed1979

Ruminal and salivary concentration of some sulphonamides in cows and their effect on rumen flora.

Sulphadiazine, sulphatiazole and sulphamerazine were shown to be excreted through the ruminal wall and salivary glands of cows. These sulphonamides had a slight inhibitory effect on cellulose digestion and on the activity of rumen infusoria. Acetylation of the sulphonamides occurred to a slight extent. Sulphatiazole was more acetylated (16.2 per cent) than sulphadiazine (7.0 per cent) or sulphamerazine (8.4 per cent). The rate of elimination of the three compounds, as indicated by their half lives, showed that sulphathiazole was the most rapidly excreted (2 h), whereas sulphadiazine and sulphamerazine were more slowly excreted, 5.4 and 7.1 h respectively.

Animals↗
PubMed1975

Metabolism of sulphadiazine in goats.

1. Following intravenous administration of sulphadiazine (2-sulphailamido-pyrimidine) to goats, unchanged sulphadiazine comprised the major part of the total sulphonamide in blood plasma, milk and urine samples. 2. Relatively small amounts of N4-acetysulphadiazine were excreted in milk and urine. The amount of conjugated metabolites in urine was small, but was comparatively large in the milk samples. 3. A new metabolite, 2-sulphanilamido-4-hydroxyprimidine, which comprised about 15% of the total sulphonamide in urine was isolated.

Animals↗
PubMedDate not supplied

Disposition of tylosin in goats.

The disposition kinetics of tylosin was studied in goats after intravenous (i.v.) or intramuscular (i.m.) injection of 15 mg/kg body wt. Following i.v. injection, tylosin was rapidly and widely distributed with a distribution half-life of 0.2 h and volume of distribution of 1.7 l/kg. It was slowly eliminated with a mean elimination half-life of 3.04 h and a total body clearance rate of 6.8 ml/kg/min. Following i.m. injection, tylosin was slowly absorbed (tau 1/2 ab of 1.82 h). Tylosin concentration in serum was greater than 1 microgram/ml after 1 h and persisted up to 12 h post-injection. The peak concentration (Cmax 2.38 micrograms/ml) was obtained after 4.19 h. The systemic bioavailability of tylosin injected intramuscularly was 72.6% and the serum protein bound fraction was 37.59% of the total drug. Tylosin was excreted in milk and urine at concentrations much higher than that in serum. Low concentrations of tylosin were reported in ruminal juice of goats. In conclusion tylosin should be injected every 14 h to obtain an appreciable concentration in serum, milk and urine.

Absorption↗
PubMedDate not supplied

Sulphonamides in buffaloes: effect on certain blood constituents and serum enzymes.

1. Three groups of four clinically healthy buffaloes were injected with sulphadiazine, or sulphadimidine, or sulphathiazole in a single dose of 100 mg/kg body weight. 2. Changes in the serum enzyme activities (SGOT, SGPT and alkaline phosphatase) observed with the tested sulphonamides were insignificant, except for increases in SGOT level 6 h after sulphathiazole injection, and in GOT/GPT ratio 30 min and 24 h after sulphadimidine injection. 3. The creatinine level was not affected in sulphonamide-injected animals. All blood samples collected 15 min to 24 h after sulphathiazole injection showed marked increase in glucose and urea levels. Concerning the other two sulphonamides, no significant change was observed in these parameters except for an increased glucose level 24 h after sulphadiazine injection.

Alanine Transaminase↗
PubMedDate not supplied

Kinetic disposition, systemic bioavailability, tissue levels and acetylation of some sulphonamides in goats.

Sulphamethoxazole, sulphadimethyloxazole and sulphadimethoxine were once administered in goats via oral and i.v. route (100 mg/kg b.wt.) for determination of plasma and urine concentrations of the unchanged sulphonamides and their acetylated derivatives, kinetic behavior, systemic bioavailability, tissue levels and acetylation. The highest plasma concentrations of sulphamethoxazole, sulphadimethyloxazole and sulphadimethoxine were reached after 0.64, 1.31 and 0.46 hr following oral administration, with an absorption half-life of 0.84, 1.31 and 0.38 hr and an elimination half-life of 3.51, 5.01 and 5.55 hr, respectively. Following a single i.v. injection, the kinetic disposition of sulphamethoxazole and sulphadimethoxine followed a one-compartmental model with an elimination half-life of 1.48 and 1.76 hr and a total body clearance-time curve of sulphadimethyloxazole, after a single i.v. injection, could be described by a two-compartmental open model with an elimination half-life of 3.27 hr, a volume of distribution of 248.07 ml/kg and a total body clearance of 0.82 ml/kg/min. The systemic bioavailability was 19.95, 11.37 and 23.27% after oral administration of sulphamethoxazole, sulphadimethyloxazole and sulphadimethoxine, respectively. The percentages of serum protein binding of sulphamethoxazole, sulphadimethyloxazole and sulphadimethoxine were determined in most of the body tissues, collected 4 hr after i.v. injection. The highest concentration was found in kidney and liver. On the other hand, sulphamethoxazole, sulphadimethyloxazole and sulphadimethoxine were N4-acetylated in the body tissues to a higher extent than that in plasma. Acetylation was highest in rumen and skeletal muscle.

Acetylation↗