PubMed Health⌕ Search

Biomedical subjects

J Vanĕcek

Publications and source records attributed to J Vanĕcek.

At least 73 records · Page 4Linked to original sources

Ontogenic drug studies in calves. II. Changes in salicylate levels and metabolism in calves with diarrhoea.

Acetylsalicylic acid (ASA) was administered by oral route to calves and mice. A comparison of plasma levels of salicylates and salicyluric acid was performed in healthy and diarrhoic calves. The calves were infected with E. coli enterotoxin producing strains. During the 6 h observation period increased levels of salicylates were found in all age groups of calves (1-60 days). There were no significant differences in salicyluric acid plasma levels between controls and diarrhoic animals. Intravenous injection of cholera toxin in mice caused lower levels of total salicylates, but increased levels of salicylic acid and salicyluric acid. The importance of adequate animal model is discussed.

Animals↗

Ontogenic drug studies in calves. I. Age dependent salicylate levels and metabolism.

Acetylsalicylic acid (ASA) was administered to 52 Friesian calves 1--60 days old by oral route in the field, 63.5 mg/kg body weight constantly between 9 and 10 a.m., i.e., 3--4 h after morning feeding. The animals were divided according to age into groups. Total salicylate levels, salicylic acid and salicyluric acid plasma levels were determined up to 6 h after administration. The older the animals, the lower were the total salicylate and salicylic acid levels and the higher the salicyluric acid levels. The age dependence is highly significant during the first two weeks of life. Glucuronides could not be detected in quantitatively measurable amounts.

Aging↗

Immunoglobulin levels in large calf agglomerations.

The zinc sulphate turbidity test was used to establish the total immunoglobulin levels of calves from birth to 4 months of age. Colostral immunity fell rapidly and the lowest levels were found in the third and fourth week of life. During the fifth week there was a significant increase. 25% of animals were hypogammaglobulinaemic in the first week of life. This ratio increased to 50% in the third week of life. At the age of two months the lowest immunoglobulin levels almost vanished. These findings are discussed as basic information for the appropriate management of calf agglomerations. Animals should be agglomerated only after the first months of life. When this is not possible, the pens for large agglomerations should have individual housing for the newly admitted calves. The importance of appropriate epizootological measures to reduce infections are pointed out.

Age Factors↗

Effect of dihydroxyphenylalanine, imipramine and coffeine on the light induced decrease in nocturnal serotonin N-acetyltransferase in the rat pineal gland.

The s.c. administration of 150mg L-dihydroxphyenylalaine/kg b.w. 15 min before the decapitation prevents the light induced decrease in nocturnal serotonin N-acetyltransferase activity in the rat pineal gland. The s.c. administration of 50mg imipramine/kg b.w., resp. 100mg/kg b.w., 15 min before the decapitation, slows down, or prevents the light induced fall in the activity. The maintenance of a sufficient level of active norepinephrine on beta-receptors, either by displacement of norepinephrine in the nerve endings by dopamine, or by the inhibition of norepinephrine reuptake by imipramine, thus slows down or prevents the decrease in serotonin N-acetyltransferase activity after exposure to light during the night. The i.p. administration of a phosphodiesterase inhibitor coffeine citrate in a dose 200mg/kg 90 min after switching off the light for the night stimulated serotonin N-acetyltransferase activity 270 min after the light and been switched off, but did not influence the abrupt decrease induced in nocturnal activity by exposure to light.

Acetyltransferases↗

Pregnancy interrupting effects of some bacterial toxins.

Embryotoxic properties of Shigella dysenteriae and Clostridium perfringens toxins, of E. coli endotoxin, V. cholerase and E. coli enterotoxins were compared in mice. E. coli endotoxin has embryotoxic effects at all stages of pregnancy. E. coli enterotoxin V. cholerae enterotoxin and Shigella dysenteriae toxin are most effective mainly at earlier stages of pregnancy. Clostridium perfringens toxin has no embryotoxic effect.

Abortifacient Agents, Nonsteroidal↗

[Effect of tylosin in pigs].

The effect of tylosine and sulphadimidine, chlortetracycline, and bacitracin in feed was studied in 1275 piglets from 120 litters; the values obtained were compared with the control group given no antibiotics. Three Tylan injections were applied to a half of the animals on the 2nd, 5th, and 28th day after birth. The Tylan program did not lead to any significant reduction of piglet mortality before the 50th day of life. In neither of the groups did Tylan injections reduce mortality at the level of statistical significance. From the age of 56 days, the Tylan-application program provides statistically significant weight gains, as compared with other groups. The group with Czechoslovak antibiotics had the same weight as the group fed without antibiotics. The occurrence of pathological and anatomic findings on lungs showed no statistically significant differences in the two groups. The presence of tylosine in blood could not be ascertained after the oral application of even much higher doses than those used in the Tylan-application program. Small incidence of rhinitis does not allow for drawing any conclusions concerning the effects of Tylan.

Animal Feed↗