Biomedical subjects

H J Breukink

Publications and source records attributed to H J Breukink.

At least 19 recordsLinked to original sources

PubMed1992

Failure of adrenocorticotrophic hormone to release serum amyloid A in cattle.

The objective of this study was to determine whether adrenocorticotrophic hormone plays a direct role in the secretion of serum amyloid A (SAA) in cattle. Seven lactating Holstein-Friesian cows were given either saline or 25 iu adrenocorticotrophic hormone (ACTH) intravenously at 09.00 in a two factor crossover design. Plasma cortisol concentrations had increased significantly by one hour after the injection of ACTH, whereas the SAA level had not increased by 24 hours after injection. It is concluded that in cattle adrenocorticotrophic hormone has no direct influence on the release of SAA by the hepatocyte.

Adrenocorticotropic Hormone↗

PubMed1992

Effects of different iron contents in the milk replacer on the development of iron deficiency anaemia in veal calves.

The effect of different iron concentrations in the milk replacer on the development of iron deficiency anaemia during a fattening period of 28 weeks was studied in three groups of 14 calves. The iron contents in the milk replacer differed during the first seven weeks: 60, 100 and 150 mg Fe/kg in groups A, B and C, respectively. In all three groups blood haemoglobin, mean corpuscular volume, plasma iron concentration and saturation decreased during the fattening period, whereas the total iron-binding capacity increased. At week 7, liver iron concentrations were high with a large individual variation [A: 201 (61-706), B: 99 (47-129), C: 296 (77-1572) micrograms/g dry matter]. During the fattening period, liver iron concentrations decreased, with the lowest values at week 25 [A: 54 (34-82), B: 55 (44-83), C: 57 (42-79) micrograms/g dry matter]. Muscle iron concentrations decreased between week 7 and 19. Except plasma iron and saturation in group C, no differences in haematological and tissue iron variables were found throughout the fattening period in spite of different iron contents in the milk replacer during the first seven weeks.

Anemia, Hypochromic↗

PubMed1992

The pathogenesis of the post-weaning syndrome in weaned piglets: a review.

This review deals with the pathogenesis of the post-weaning syndrome. This syndrome includes post-weaning diarrhoea (PWD), oedema disease (OD) and endotoxin shock (ES). The role of different enteropathogenic Escherichia coli bacteria and some other predisposing factors relating to this post-weaning syndrome (PWS) are discussed. Based on intestinal pathophysiological mechanisms, some suggestions for the prevention of PWS and prospects for future research are given.

Animals↗

PubMed1992

Relationship between blood hemoglobin, plasma and tissue iron, muscle heme pigment, and carcass color of veal.

In 41 veal calves divided into three groups and fed different levels of dietary iron, blood hemoglobin, plasma iron, liver, spleen, and muscle iron, muscle heme pigment, and carcass muscle color at slaughter were studied. At 45 min postmortem, total carcass color was visually evaluated in the 41 carcasses. In different muscles of the carcasses the color was measured instrumentally using an invasive color measurement method at 45 min postmortem (MCDI score) and a surface color measurement method at 20 h postmortem (Minolta L*, a*, b*, and Chroma scores). Among the three groups, differences (P less than .05) in muscle iron concentrations, muscle heme pigment concentrations, and Minolta a*, b*, and Chroma scores were found. Most striking were the differences in mean iron concentrations in the longissimus thoracis muscles between Groups A (29 micrograms/g DM) and B (44 micrograms/g DM) and in the semimembranosus muscles between Groups A (31 micrograms/g DM) and C (45 micrograms/g DM). The correlations found between Minolta L*, a*, or Chroma score and the iron and heme pigment concentrations in the semimembranosus muscles were high in comparison with those found in the longissimus thoracis and rectus abdominis muscles. Compared with the plasma iron concentration, the blood hemoglobin concentration showed higher correlations with muscle iron and muscle heme pigment concentrations. It can be concluded that different iron concentrations in the milk replacer during the first 7 wk of fattening influence, to some extent, muscle iron and muscle heme pigment at slaughter. However, these differences were not measurable in the overall visual color evaluation of the carcass surface muscles.

Animal Feed↗

PubMed1992

Intestinal permeability in pigs during rotavirus infection.

Macromolecular permeability of the small intestine was tested in four 3-week-old gnotobiotic pigs inoculated with porcine rotavirus strain RV277 (group A). Pigs were administered 125I-labeled polyvinylpyrrolidone (molecular weight [mol wt], 40,000) orally 1 day before and 2 and 24 hours after virus inoculation, and blood samples were obtained every 6 hours. Eight hours after rotavirus inoculation, pigs had watery diarrhea. Increased permeation of 125I-labeled polyvinylpyrrolidone was not observed after clinical signs of infection had developed. Serum total protein and urea nitrogen concentrations increased slightly at the end of the study, probably as a consequence of dehydration. Differences in blood glucose concentration were not seen. At 48 hours after viral inoculation, macromolecular permeability was tested morphologically by injecting horseradish peroxidase (mol wt, 40,000) into the jejunal lumen just distally to the ligamentum colicoduodenale. After an incubation period of 20 minutes, small segments of jejunum were obtained for stereomicroscopic, histologic, and ultrastructural investigations. Moderate hyperregenerative villus atrophy was found. Ultrastructural changes of the villus epithelium were minor, and increased macromolecular permeation was not observed.

Animals↗

PubMed1991

Value of standardised exercise tests and blood biochemistry in the selection and training of breeding stallions.

Stallions selected by the Royal Dutch Warmblood Society were submitted to a standardised lungeing test at the beginning and at the end of a 100-day test of performance and ability. The heart rate, haematology and biochemistry values obtained in the first lungeing test showed no significant differences between the 15 stallions which were rejected by the Royal Dutch Warmblood Society during the first month of the 100-day test, the 15 stallions rejected during the last month and the 11 stallions which were approved for registration in the studbook. The 26 stallions submitted to the second lungeing test had significantly lower heart rates and blood lactate concentrations than in the first test. The standardised lungeing test had no value in predicting the rejection or approval of the stallions, and the fitness of a stallion at the beginning of the 100-day test did not influence its chance of being approved as a breeding stallion. The differences between the results of the first and the second tests suggest that the fitness of the stallions improved during the 100-day test.

Animals↗

PubMed1991

Heart rate, blood biochemistry and performance of horses competing in a 100 km endurance ride.

To determine whether a clinical examination was adequate to assess the fitness of horses in an endurance ride, and to characterise the relationship between a clinical assessment of the horse's fitness and its blood biochemistry, 23 horses were monitored before, during and after an 87 to 100 km endurance ride. Blood samples were taken before the ride, at three checkpoints on the ride, immediately after the ride and one day later for the determination of packed cell volume, total protein, lactate, glucose, non-esterified fatty acids, creatine phosphokinase, aspartate aminotransferase and plasma electrolytes. Heart rate measurements appeared to be a reliable indicator of the metabolic status of endurance horses suggesting that veterinary examinations according to the official Fédération Equestre Internationale rules are adequate to protect the health and welfare of horses competing in endurance races.

Animals↗

PubMed1991

Udder oedema associated with adrenocortical insufficiency in a herd of Holstein/Friesian cows.

The possible involvement of the pituitary-adrenocortical axis with severe pre- and post partum udder oedema was studied in a herd of 60 Holstein/Friesian cows. The prevalence of udder oedema in this herd was about 75 per cent. The animals were fed a diet containing high levels of potassium (average daily potassium intake 410 g per cow). The concentrations of sodium, potassium, chloride and total protein in the plasma of the cows were within their normal ranges. In one animal a very low plasma cortisol concentration (2.30 ng/ml) was accompanied by normal plasma glucose and beta-hydroxybutyrate concentrations. The adrenal responsiveness of two heifers with severe udder oedema was impaired one month after parturition in comparison with 11 normal animals (increases from 3.27 to 38.8 and 23.2 to 37.8 ng cortisol/ml compared with 8.02 +/- 1.19 to 146 +/- 16.7 ng cortisol/ml but returned to normal spontaneously after 175 days. One cow was diagnosed as having primary adrenocortical insufficiency.

Adrenal Insufficiency↗

PubMed1991

Adrenocortical function testing in dairy cows and its effect on milk yield.

Administration of 6IU synthetic ACTH1-24 intravenously to six Holstein-Friesian cows resulted in a cortisol peak concentration after 1 hour of 148 +/- 34.2 ng/ml. Basal plasma cortisol concentration (4.84 +/- 0.83 ng/ml) was reached 5 hours after ACTH injection. Until 7 days after ACTH administration no effect on milk yield was recorded. So it is concluded that a dose of 6 IU ACTH1-24 is sufficient for a conspicuous release of cortisol without any alteration in milk production. This dose can be used as a standard test for the evaluation of adrenocortical function in lactating cows when administered intravenously at 9 a.m. and when plasma samples for cortisol assay are collected just prior to administration and at 10 a.m.

Adrenal Cortex↗

PubMed1991

Effects of experimentally induced Pasteurella haemolytica infection in dairy calves on the pharmacokinetics of flumequine.

The effect of experimental Pasteurella haemolytica infection on the intravenous and intramuscular pharmacokinetics of flumequine was studied in dairy calves. The plasma concentration-time curve of flumequine after intravenous injection of 5 mg/kg bodyweight flumequine of a 10% solution before and after experimental infection, was best described by a three-compartment open model. After intramuscular injection of the same dosage rate of a 3% flumequine suspension is was best described by the one-compartment open model with first-order absorption. The experimental infection by intratracheal administration of infectious bovine rhinotracheitis (IBR)-virus and 5 days later intrapulmonary administration of Pasteurella haemolytica produced a clear temperature rise and signs of disease expressed as Average Health Status. Subsequently, plasma Fe and Zn concentration decreased after infection. The distribution volumes Vc, Vd(area) and Vd(ss) after infection (0.07 +/- 0.04, 1.38 +/- 0.36 and 0.50 +/- 0.11 l/kg, respectively) were smaller than those before infection, but the differences were not significant (P less than or equal to 0.1). The intravenous AUC infinity was significantly increased (21.86 +/- 3.51 to 33.85 +/- 2.97 mg.h/l, P less than or equal to 0.01) and the total body clearance (ClB) significantly decreased (0.24 +/- 0.02 to 0.15 +/- 0.01, P less than or equal to 0.01) after infection. After intramuscular injection of flumequine at 5 mg/kg as a 3% suspension, only the bioavailability, F, was significantly decreased after infection (78.5 +/- 14.3 to 59.7 +/- 21.2%, P less than or equal to 0.02). However, this had no consequences for the dosage regimen used. The urine concentration ratio flumequine:7-hydroxy-flumequine:conjugated flumequine changed from 2:1:10 before infection to 6:1:15 after infection, which indicates that hydroxylation and glucuronidation as metabolic pathways for flumequine were decreased after Pasteurella sp. infection.

Animals↗

PubMed1991

Blood hemoglobin, plasma iron, and tissue iron in dams in late gestation, at calving, and in veal calves at delivery and later.

The effect of 100 ppm of Fe in milk replacer on some hematological and tissue Fe variables was studied during the first 7 wk of the fattening period in two groups of eight calves with low or high initial blood hemoglobin concentrations. Hemoglobin concentration in calves with initially low hemoglobin increased. It decreased in those with initially high hemoglobin, but the difference remained over the experimental period. Higher mean liver Fe concentration, in some cases extremely high, and lower mean total Fe-binding capacity were found throughout the experiment in the group with the initial high hemoglobin. Of all variables, only low muscle Fe concentrations were correlated linearly with plasma Fe. In another experiment, the relationship of some hematological and tissue Fe variables during late gestation (about 10 d prepartum), at calving in dams, and at delivery in calves was investigated. The calves showed markedly higher liver Fe concentrations at delivery than their dams just before delivery, but these liver Fe concentrations were not correlated between dam and calf. The hematological and tissue Fe variables showed a weak correlation between dams and calves during late gestation or at delivery. However, dams as well as calves were Fe-sufficient.

Animals↗

PubMed1990

[The role of veterinary toxicology in farm animals].

The history of veterinary toxicology in farm animals, like that of human toxicology, is marked by a number of classical, large-scale cases of poisoning, which have become widely known. A number of these cases are briefly reported, attention being drawn to the specific problems to which they give rise. Publicity, liability, diagnostic problems and amount of loss often have a delaying effect on settlements. Methods which might improve this situation are broadly outlined.

Animal Husbandry↗

PubMed1990

Intraruminal administration of milk in the calf as a model for ruminal drinking: morphological and enzymatical changes in the jejunal mucosa.

In order to develop a calf model for studying the syndrome of ruminal drinking (RD) in veal calves, three dual-fistulated calves were used to test the effect of intraruminal administration of milk replacer on the jejunal mucosa. Biopsies of the proximal jejunal mucosa were taken through a jejunal fistula and the mucosal morphology and the activities of two brush border enzymes, lactase and alkaline phosphatase, were determined. Means of villus length and brush border enzyme activities decreased during the period of intraruminal administration of milk. The hyperplastic villus atrophy in this model was similar to that found in chronic RD patients in previous studies. This could not be associated with isolation of pathogenic micro-organisms from the faeces and is probably the consequence of the intraruminal milk feeding procedure itself. Clinical recovery from the signs of RD occurred rapidly after intraruminal administration of milk ceased and was followed by restoration of villus length and brush border enzyme activities 3-4 weeks later.

Alkaline Phosphatase↗

PubMed1990

In vitro activity of flumequine in comparison with several other antimicrobial agents against five pathogens isolated in calves in The Netherlands.

The in vitro activity of flumequine in comparison with several other drugs was tested against 17 P. multocida, 16 P. haemolytica, 21 S. dublin, 21 S. typhimurium and 21 E. coli strains, isolated in (veal) calves in the Netherlands. The MIC50 of flumequine for the respective pasteurellas was 0.25 and 1 microgram/ml, for the salmonellas and E. coli 0.5 micrograms/ml. In comparison with flumequine, enrofloxacin and ciprofloxacin showed higher in vitro activity, with MIC50 less than or equal to 0.008 micrograms/ml for ciprofloxacin. Decreased susceptibility of the pasteurellas was found for kanamycin, neomycin, streptomycin, gentamicin, oxytetracycline and doxycycline. The MIC50 of minocycline for P. multocida was 0.5 micrograms/ml and there was no cross resistance with the other tetracyclines. P. multocida was very susceptible to ampicillin (MIC50 less than or equal to 0.03 micrograms/ml), P. haemolytica, however, was 100% resistant to this drug. Both pasteurellas were susceptible to cephalothin and approximately 50% of the strains of both bacteria were resistant to chloramphenicol. The MIC50 of either spiramycin or tylosin was greater than or equal to their respective breakpoint-MIC values. Both pasteurellas were susceptible to the combination of trimethoprim and sulphamethoxazole. However, for P. multocida, the addition of sulphamethoxazole to trimethoprim had no synergistic effect on its MIC. In comparison with trimethorpim, aditoprim was less potent. Therefore only P. multocida was susceptible to aditoprim.

Animals↗

PubMed1990

Pharmacokinetics, metabolism and renal clearance of flumequine in veal calves.

The pharmacokinetics of flumequine was studied in 1-, 5- and 18-week-old veal calves. A two-compartment model was used to fit the plasma concentration-time curve of flumequine after the intravenous injection of 10 mg/kg of a 10% solution. The elimination half-life (t1/2 beta) of the drug ranged from 6 to 7 h. The Vd beta and ClB of 1-week-old calves (1.07 l/kg, 1.78 ml/min/kg) were significantly lower than those of 5-week-old (1.89 l/kg, 3.23 ml/min/kg) and 18-week-old calves (1.57 l/kg, 3.10 ml/min/kg). After the oral administration of 10 mg/kg of a 2% flumequine formulation mixed with milk replacer, the Cmax was highest in 1-week-old (9.27 micrograms/ml) and lowest in 18-week-old calves (4.47 micrograms/ml). The absorption was rapid (Tmax of approximately 3 h) and complete. When flumequine itself and a formulation containing 2% flumequine and 20 X 10(6) iu of colistin sulphate were mixed with milk replacer and administered at the same dose rate, absorption was incomplete and Cmax was lower. The main urinary metabolite of flumequine was the glucuronide conjugate (approximately 40% recovery within 48 h of intravenous injection) and the second most important metabolite was 7-hydroxy-flumequine (approximately 3% recovery within 12 h of intravenous injection). Only 3.2-6.5% was excreted in the urine unchanged. After oral administration a 'first-pass' effect was observed, with a significant increase in the excretion of conjugated drug. For 1-week-old calves it is recommended that the 2% formulation should be administered at a dose rate of 8 mg/kg every 24 h or 4 mg/kg every 12 h; for calves over 6 weeks old, the dose should be increased to 15 mg/kg every 24 h or 7.5 mg/kg every 12 h. The formulation containing colistin sulphate should be administered to 1-week-old calves at a flumequine dose of 12 mg/kg every 24 h or 6 mg/kg every 12 h.

Administration, Oral↗

PubMed1989

Effect of clenbuterol on the incidence of abomasal ulcers in veal calves.

The effect of clenbuterol on the incidence of abomasal lesions in veal calves was studied in two fattening units. Some of the calves in each unit were treated with 1.6 micrograms clenbuterol/kg bodyweight/day from the seventh until the 23rd week of the fattening period. In one unit the calves were fed milk replacer only and 176 of the 236 calves were treated with clenbuterol. In the other unit the calves were fed roughage pellets in addition to milk replacer and 92 of the 194 calves were treated with clenbuterol. Only in the second unit did the calves treated with clenbuterol have significantly fewer abomasal lesions.

Abomasum↗

PubMed1989

Intestinal permeability to polyethylene glycol 4000 and porcine albumin in piglets infected with transmissible gastroenteritis virus.

The intestinal permeability of specific pathogen free piglets has been studied by measuring the concentration of 14C in the blood after oral administration of 14C polyethylene glycol (14C PEG, MW = 4000) and the concentration of 131I in the faeces after intraperitoneal administration of 131I porcine albumin (131I PA, MW = 68,000). The tests were performed one day before and up to two days after the piglets were infected with transmissible gastroenteritis (TGE) virus. Jejunal biopsies were taken from two piglets before the experimental infection, from two piglets 12 h after the experimental infection and from five piglets at the end of the experiment, 46 h after infection. Blood samples were taken six-hourly and faecal samples several times. Some piglets vomited before diarrhoea and loss of appetite started at 14 h after infection; the packed cell volume decreased before but increased after infection. Morphological examination showed hyperregenerative villous atrophy at 46 h after infection. There was no increase in the permeation of 14C PEG but there was a significant increase in the flux of 131I PA from the blood to the gut lumen.

Administration, Oral↗

PubMed1989

Oral absorption and bioavailability of flumequine in veal calves.

The oral absorption and bioavailability of flumequine was studied in 1-, 5- and 18-week-old calves following intravenous and oral administration of different formulations of flumequine (Flumix, Flumix C and pure flumequine). Increasing age had a negative influence on the Cmax after the administration of Flumix, based on a larger VD in the older calves. The Cmax decreased from 5.02 +/- 1.46 micrograms/ml in the first week to 3.28 +/- 0.42 micrograms/ml in the 18th week. Adding colistin sulfate to the flumequine formulation and administring pure flumequine mixed with milk replacer had a negative effect on the Cmax of flumequine after oral administration of 5 and 10 mg/kg body weight. The bioavailability of the orally administered flumequine formulations was 100% in all cases except after the administration of Flumix C, for which it was 75.9 +/- 18.2%. The urinary recovery of flumequine after intravenous injection of a 10% solution varied from 35.2 +/- 2.3% for Group B, to 41.2 +/- 6.3% for Group C. The dosage of 5 mg/kg body weight Flumix twice daily in 1-week-old veal calves is sufficient to reach therapeutic plasma concentrations, based on a MIC value of 0.8 micrograms/ml of the target bacteria. In older calves it is advisable to increase the dosage 7.5 or 10 mg/kg body weight every 12 hours. In combination with colistin sulfate it is also advisable to increase the dosage slightly because of the negative effect of the colistin sulfate on the Cmax of flumequine.

Administration, Oral↗