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Biomedical subjects

M Wanner

Publications and source records attributed to M Wanner.

At least 73 records · Page 4Linked to original sources
PubMed1993

Pharmacokinetics of the gyrase inhibitor marbofloxacin: influence of pregnancy and lactation in sows.

Six pregnant sows were treated in early pregnancy, late pregnancy and during lactation. Marbofloxacin was administered (2 mg/kg body weight) intravenously and orally. The active drug concentration in the plasma was quantitated by use of high performance liquid chromatography (HPLC). Pharmacokinetic parameters were calculated by use of statistical moments. In lactating animals, the concentrations in milk were also determined by HPLC. Mean elimination half-life of the drug after oral administration was significantly shorter in lactating sows (5.74h) than that of the early pregnancy group (10.09h). Total body clearance was highest in the lactating sows (3.27 ml/minute.kg body weight). The volume of distribution was large in all physiological states studied indicating good tissue penetration. Bioavailability was about 80% in pregnant and lactating sows. Antimicrobial secretion in milk contributed greatly to marbofloxacin elimination. These results indicate an important influence of lactation on marbofloxacin pharmacokinetics in sows. Therefore, in such cases, marbofloxacin dose should be increased during lactation.

Administration, Oral↗
PubMed1993

Research note: pharmacokinetics of aditoprim in turkeys after intravenous and oral administration.

The pharmacokinetics of aditoprim, a not yet commercialized selective reversible inhibitor of dihydrofolate reductase, were determined in turkeys after intravenous (5 mg/kg BW) and oral (5.46 +/- .44 mg/kg BW) administration. The mean (+/- SD) total body clearance of 26.9 +/- 2.3 mL/min per kg BW was high when compared with that determined for other species, presumably a consequence of the higher metabolic rate of birds. Consequently, mean aditoprim elimination half-life was relatively short (3.3 +/- .2 h). As determined in mammalian species, the apparent volume of distribution at steady state was large. Aditoprim in drinking water (100 and 300 mg/L water) provided plasma concentrations between .08 and .19 micrograms/mL. Circadian rhythms with highest concentrations in the late afternoon and lowest concentrations in the morning were observed. Despite its short elimination half-life, aditoprim may still be a valuable antimicrobial for use in avian medicine pending safety, efficacy, and residue depletion studies.

Administration, Oral↗
PubMed1993

Influence of tiamulin concentration in feed on its bioavailability in piglets.

Tiamulin pharmacokinetic parameters were determined in 8 2-month-old male improved Swiss Landrace piglets after intake of 2,000 mg/kg feed, 500 mg/kg feed, 12.5 mg/ml aqueous solution administered via a stomach tube and 180 mg/kg feed offered ad libitum. In all cases, the total tiamulin dose received was 10 mg/kg body weight (bw) per day. For the 2,000 mg/kg and 500 mg/kg treatments, animals were restrictively fed a commercial mix in amounts corresponding to 3-fold their maintenance requirement of digestible energy. The piglets first individually received the amount of medicated feed and immediately thereafter the rest of the daily ration. The highest tiamulin serum concentrations (Cmax), the largest area under the curve (AUC0-->infinity), the largest absorption rate constant (Ka), and the shortest time at which the maximum serum concentration occurred (tmax) were obtained after administration via stomach tube followed in the respective order by the 2,000 mg/kg, 500 mg/kg and 180 mg/kg treatments. Ad libitum feeding of the medicated mix at 180 mg/kg failed to provide tiamulin serum concentration above minimum inhibitory concentrations (MIC) of some representative microorganisms. In conclusion, tiamulin concentration in medicated feed strongly influences its rate and extent of absorption and consequently serum concentrations. Larger tiamulin concentration in feed enhances its bioavailability. The common practice adopted by national regulatory agencies for the registration of a new drug is to conduct pharmacokinetic studies after administration agencies for the registration of a new drug is to conduct pharmacokinetic studies after administration via a stomach tube. This practice should be reevaluated because this mode of administration does not correspond to that in routine use.

Administration, Oral↗
PubMed1993

[The effect of pregnancy and lactation in sows on the pharmacokinetics of the gyrase inhibitor marbofloxacin].

Six pregnant sows were treated in early pregnancy, late pregnancy and during lactation. Four empty sows served as control. Marbofloxacin was administered (2 mg/kg body weight) intravenously and orally. The active drug concentration in the plasma was quantitated by use of high performance liquid chromatography (HPLC) and microbiological assay. Pharmacokinetic parameters were calculated by use of a noncompartment model. In lactating animals, the concentrations in milk were also determined by HPLC. Mean elimination half-life of the drug after oral administration was significantly shorter in lactating sows (5.74 h) than that of the early pregnancy group (10.09 h). Total body clearance was highest in the lactating sows (3.27 ml/minute.kg body weight). The volume of distribution was large in all physiological states studied indicating good tissue penetration. Bioavailability was about 80% in pregnant and lactating sows. Antimicrobial secretion in milk contributed greatly to marbofloxacin elimination. These results indicate an important influence of lactation on marbofloxacin pharmacokinetics in sows. Therefore, in such cases, the antibiotic dose should be increased during lactation.

Administration, Oral↗
PubMed1992

The influence of age on the pharmacokinetics of aditoprim in pigs after intravenous and oral administration.

Some pharmacokinetic parameters of aditoprim were determined in 3- and 6-month-old pigs. After intravenous administration of 5 mg/kg body weight, the mean total body clearance of the older pigs was smaller than that of the younger pigs. This difference was not reflected in the elimination half-life. After oral administration of 5 mg/kg body weight, the mean absorption rate constant was smaller and the mean absorption half-life was longer in the older pigs. The age-related changes in the pharmacokinetics of aditoprim were not sufficiently pronounced to suggest the necessity of modifying the oral dosage regimen in pigs of this age range. The favourable pharmacokinetics of aditoprim in pigs (large apparent volume of distribution, long elimination half-life and high bioavailability) may permit introduction of this drug into swine practice, after safety and residue depletion studies.

Administration, Oral↗
PubMed1992

Effects of endotoxin-induced mastitis on the pharmacokinetic properties of aditoprim in dairy cows.

Plasma disposition of aditoprim, a new dihydrofolate reductase inhibitor, was studied in healthy cows and cows with endotoxin-induced mastitis. A single dose of 5 mg of aditoprim/kg of body weight was administered IV to 5 healthy cows and to the same cows 3 weeks later at 2 hours after intramammary infusion of 0.1 mg of endotoxin into the rear quarters. Mastitis developed in all endotoxin-infused quarters and cows had systemic signs of disease (fever, tachycardia, depression) from 2 to 10 hours after infusion of endotoxin. Pharmacokinetic characteristics of aditoprim in healthy cows were a large volume of distribution (6.28 L/kg), a systemic clearance of 0.82 L/h/kg, and an elimination half-life of 7.26 hours. In cows with mastitis, plasma concentrations of aditoprim were lower between 5 and 26 hours after injection. The systemic clearance (1.00 L/h/kg) and the volume of distribution (12.25 L/kg) were significantly higher in cows with mastitis, but elimination half-life was not significantly different. The lower plasma concentrations of aditoprim between 5 and 26 hours after injection in cows with mastitis are explained by fluid compartment shifts and/or blood flow changes induced by mastitis, although increased elimination of aditoprim in cows with mastitis cannot completely be ruled out. The antibacterial activity of aditoprim is nearly the same as that of trimethoprim. The longer elimination half-life time of aditoprim, however, indicates that it may have a practical pharmacotherapeutic advantage over trimethoprim.

Animals↗
PubMed1991

Influence of dietary citric acid and calcium on the bioavailability of orally administered chlortetracycline in piglets.

In a study involving 18 piglets divided into three groups (A, B and C), the effects of dietary calcium and citric acid, and feeding technique on chlortetracycline bioavailability were examined. Groups of 6 animals received a basal diet with either 0.7% (group A) or 1.4% calcium (groups B and C). Citric acid was not included in diets of the first experimental period. In the second period, either 1.5% (groups A and B) or 3.0% (group C) citric acid was added to the diet. In both experimental periods, chlortetracycline was administered once intravenously (7.5 mg/kg b.w.) and once orally (30 mg/kg b.w.). After each administration, blood samples were taken at regular intervals in order to determine chlortetracycline serum concentrations by a microbiological method. Following oral chlortetracycline intake, low dietary calcium or citric acid addition to the diet produced increased chlortetracycline serum concentrations. Chlortetracycline bioavailability was 12.6% at 0.7% dietary calcium, and 9.5% at 1.4% dietary calcium. Enteral chlortetracycline absorption was improved 65% with 1.5% or 3.0% dietary citric acid supplementation. An 8-hour delay of feed intake following oral chlortetracycline intake did not significantly influence chlortetracycline bioavailability.

Administration, Oral↗
PubMed1990

[Effect of citric acid and calcium on the bioavailability of orally-administered oxytetracycline in piglets].

The bioavailability of orally given oxytetracycline in dependence on calcium (0.7% and 1.4% calcium, respectively) and citric acid content in feed was examined in piglets (9.9 +/- 0.9 kg body weight). In the first trial no citric acid was added to the two feeds, in the second trial 1.5% citric acid was added. In both trials each piglet received an i/v-injection of oxytetracycline (dosage 10 mg/kg body weight) and an oral dose of oxytetracycline (40 mg/kg body weight). The blood samples, taken in definite time intervals, were analysed by a microbiological assay. With these results the kinetic parameters and the bioavailability were calculated. The results of the i/v-trials were identical. The kinetic parameters C1 = 14.91 micrograms/ml, lambda 1 = 3.46 h-1, Cz = 7.49 micrograms/ml and lambda z = 0.19 h-1 describe the graph after i/v-application. The calcium content of the feed had no significant influence on the kinetic parameters after p/o-application, but the piglets receiving citric acid showed a significant higher maximum concentration (Cmax). The bioavailability of orally given oxytetracycline was significantly (26%) increased by the citric acid content. In spite of the citric acid the bioavailability only came to 4.9%.

Administration, Oral↗
PubMed1990

[The effect of feed preparation on the pharmacokinetics of peroral administration of chlortetracycline in weaned piglets].

The influence of different modes of feeding on the bioavailability of orally administered chlortetracycline was studied in weaned pigs. The animals were divided into three groups receiving a dry, a moist or a soup diet, respectively. CTC was applied at a concentration of 6000 ppm and 2500 ppm to each diet and the oral dosage of CTC was 40 mg chlortetracycline/kg bodyweight. The results of the experiments show that the pharmacokinetics of orally applied chlortetracycline are significantly influenced by the mode of feeding. A significantly higher bioavailability was observed with soup feeding compared with moist or dry food. To achieve a therapeutic blood level of 0.5-1.5 micrograms chlortetracycline/ml blood, 20-30 mg chlortetracycline/kg bodyweight/12 h and 30-40 mg chlortetracycline/kg bodyweight/12 h should be applied to soup and dry or moist feed, respectively.

Administration, Oral↗
PubMed1990

[Feed preparation and pharmacokinetics of chlortetracycline in piglets].

18 piglets were fed either a dry, humid or soup diet and each animal was dosed with 40 mg chlortetracycline/kg bodyweight. The chlortetracycline-concentration in the diet was 2500 mg/kg air-dried feed. After a single oral dosage the absorption of chlortetracycline occurred significantly faster from the soup diet, resulting in higher serum levels as well as prolonged elevated serum concentrations of CTC compared with the other two diets. Using a mathematical model, serum concentrations over a 5-day period with repeated dosage of CTC were calculated. Based on this dates we recommend the following dosage regime for chlortetracycline: 20-30 mg CTC/kg bodyweight/12 h for soup feeding and 30-40 mg CTC/kg bodyweight/12 h for dry or humid feeding.

Administration, Oral↗
PubMed1989

[The feeding of dogs in Switzerland. The results of an inquiry].

Results of inquiry made of 2190 dog owners about customs of feeding and keeping dogs in Switzerland are presented. The diet most often used consists of cereal flakes which are given together with feedstuff from animals or other commercial dogfood. Usually, only one meal per day is given and the amount of food is based on a constant body weight. Regular feeding of bones appears to have a good effect on digestion and dental health.

Animal Feed↗
PubMed1986

[Pregnancy, labor and the puerperium in paraplegic patients].

Due to better care and better knowledge pregnancies in paraplegic patients nowadays have a good prognosis. We report on 16 deliveries in 13 paraplegic or tetraplegic patients. To minimise the danger of possible further damage it is important to know about the special problems associated with pregnancies in paraplegic mothers. It is particularly important to know about the elevated risk of premature labour and the risk of autonomic hyperreflexia in lesions above D7. To prevent urogenital infections, patients should try to keep the genital region clean and try to empty the bladder as completely as possible. Intermittent catheterisation might be necessary. One should try to prevent decubital ulcers, and therefore an eventual anaemia (below 80%) should be corrected by transfusions. The patients should be instructed how uterine contractions can be palpated manually because sometimes perception of contractions in other ways is not possible. Repeated examinations of the cervix also help to prevent premature birth. Hospitalisation of the mother two to three weeks before the expected date of birth is suggested. If the lesion is higher than D7, symptoms of autonomic hyperreflexia (bradycardia and rise of blood pressure with the risk of cerebral haemorrhagia) are almost always present when labour starts. To prevent this possibly life-threatening complication, early application of epidural anaesthesia is suggested. There is no contraindication to spontaneous delivery. Vacuum extraction or forceps are necessary more frequently. In the post-partal period, prophylaxis of decubital ulcers is important. Breast feeding is not influenced.

Adult↗
PubMed1985

[Effect of milk constituents on lipid metabolism].

The cholesterol lowering effect of various milk constituents was examined in six trials with growing pigs. Each trial is described. By means of main component analysis 44 factors were tested in order to see whether they influenced the lipid metabolism. We observed that there was no specific component in the milk which showed a cholesterol lowering effect. Milk and milk constituents change the nutrient composition of the food and can, e.g. by means of the changed amino acid pattern, indirectly lower the lipid content in the blood.

Animals↗
PubMed1985

Variations of 3-methylhistidine in blood of dairy cows.

Blood plasma 3-methylhistidine, in comparison with other blood variables, has been measured in high-yielding dairy cows with relation to energy and protein supply. Circulating 3-methylhistidine markedly increased to 1 wk after calving, then continuously decreased to 5 wk postpartum to lower than during the last 2 wk of pregnancy. In experiments 36 d after calving, circulating 3-methylhistidine did not change during 24 h despite marked variations of food intake. Peak 3-methylhistidine immediately after parturition coincided with relatively low insulin, thyroxine, triiodothyronine, glucose, protein, and urea with elevated concentrations of nonesterified fatty acids and with greatest estimated energy and protein deficiencies. However, during the ensuing period to 12 wk of lactation, circulating 3-methylhistidine was not closely related to these measures nor to creatinine, beta-hydroxybutyrate, and milk production, but relationships to milk protein yield were close. The postparturient increase of 3-methylhistidine may have been a consequence of enhanced breakdown of skeletal muscle and uterine smooth muscle or another pool with a transiently enhanced turnover rate. Variations of plasma 3-methylhistidine were associated only in part with estimated negative energy and protein balances and corresponding endocrine and metabolic adaptations.

Animals↗