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Biomedical subjects

T Wensing

Publications and source records attributed to T Wensing.

At least 73 records · Page 4Linked to original sources
PubMed1991

Effect of Trypanosoma vivax infection on energy and nitrogen metabolism of west African dwarf goats.

A study was conducted using 32 mature 22-kg West African Dwarf Goats to measure the effect of Trypanosoma vivax infection on energy and nitrogen metabolism. Sixteen goats were infected intravenously with 14 X 10(6) T. vivax. Sixteen control goats were sham-injected. Digestibility and metabolizability of energy and N balance were measured for each goat. Heat production and energy balances were measured per treatment group from 1 wk before infection to 6 wk after infection. Goats were fed alfalfa pellets (10% above maintenance). Treated goats had a reduced (P less than .05) packed cell volume (38 to 40% before infection vs 20 to 25% 6 wk after infection) and an increased (P less than .05) rectal temperature. Log parasitemia/ml was about 6.0 to 6.2. Parasitized goats showed increased urine creatinine excretion at wk 2 postinfection. After infection, feed intake was reduced (about 15%; P less than .05) and greater variability in intake was noted. Treated and control goats had similar N output and energy output in urine. Metabolizability of energy intake was similar at 42.7 vs 42.1% in treated vs control goats, respectively. Heat production in infected goats was increased by about 15%. Treated goats lost more weight and had a lower N balance than control goats (P less than .05). The calculated maintenance energy requirement for infected goats (464 kJ ME/kg.75) was 25% greater than for control goats (375 kJ ME/kg.75).

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

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

Fever and changes in plasma zinc and iron concentrations in the goat. The effects of interferon inducers and recombinant IFN-alpha 2a.

Inflammation or invasion by pathogenic micro-organisms induces systemic changes, collectively known as the acute phase response. Among the varied alterations that together produce this response are fever, hypoferraemia and hypozincaemia. It is likely that these responses are mediated, in part, by production and release of cytokines such as interleukin-1 (Il-1), interferons (IFN-alpha) and tumour necrosis factor (TNF). The present report describes a comparative study in dwarf goats on recombinant human IFN-alpha 2a (0.5 x 10(5) IU per kg intravenously (i.v.) and 0.5 x 10(6) IU per kg intramuscularly (i.m.], Poly I:Poly C (an interferon inducer; 30 micrograms per kg i.v.), Newcastle disease virus La Sota strain (an interferon inducer; 0.5 ml per kg i.v.) and Escherichia coli endotoxin (an Il-1 and TNF inducer; 0.1 microgram per kg i.v.). The i.v. injection of recombinant IFN-alpha 2a caused characteristic monophasic febrile reactions, but no significant changes in plasma zinc and iron concentrations. The temperature responses were not due to endotoxin contamination because polymyxin B, which blocks endotoxin, had no inhibitory effect on the pyrogenicity of IFN-alpha 2a. In contrast, the IFN-alpha 2a-induced fever was completely prevented by flurbiprofen pretreatment (1 mg per kg i.v.). In contrast to the i.v. administration, i.m. injection of IFN-alpha 2a caused fever, hypoferraemia and hypozincaemia. Similar results were obtained after E. coli endotoxin, NCD La Sota strain and Poly I:Poly C injection. However, the shapes of the temperature curves and the changes in trace metal concentrations were markedly different. These data support the theory that fever and the changes in plasma zinc and iron concentrations are regulated by different mechanisms.

Animals↗
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

[A study of the usefulness of a metabolic profile test in determining the causes of herd problems on dairy farms in The Netherlands].

A metabolic profile test (MPT), consisting of the following parameters of the blood: glucose, urea, beta-hydroxybutyrate, copper, magnesium, calcium, non-esterified fatty acids, bilirubin, aspartate amino transferase, whole protein and the protein spectrum of the serum, was performed in twenty-two normal herds (control herds) in the Netherlands. Reference levels were estimated for the above parameters. The study showed that this MPT did not discriminate between normal herds and herds showing production problems or an increased incidence of metabolic diseases. Statistically significant differences between the three laboratories taking part in these investigations were not observed.

Animals↗
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

Comparison of the lipoprotein pattern of the horse, the pony and the lactating and non-lactating cow obtained by a combination of an ultracentrifugation and a precipitation technique.

1. The serum lipoprotein pattern was studied in four horses, four ponies and in three high producing lactating and three non-lactating cows. The lipoprotein pattern was estimated with a combination of the preparative ultracentrifugation and the heparin-manganese precipitation technique. 2. The lipid composition of the lipoproteins of horse, pony, lactating cow and non-lactating cow was determined. 3. In all three species more than 50% of serum total lipids was found in the HDL fraction. 4. The mean chylomicron fraction in horse and pony was 3.1%. In the cow it varied from 1.5 to 2.5%. 5. Between the lactating cow and the non-lactating cow there were substantial differences in the concentration of LDL and HDL. 6. The cholesterylester concentration in VLDL, LDL and HDL was clearly higher in the lactating cow than in the non-lactating cow.

Animals↗
PubMed1989

Comparative observations of fever and associated clinical, haematological and blood biochemical changes after parenteral administration of poly I: poly C, interferon-alpha 2a and Escherichia coli endotoxin in goats.

The present report describes a comparative study in dwarf goats on human IFN-alpha 2a (0.5 x 10(6) IU kg-1 body weight IM), poly I: poly C (an interferon inducer; 30 micrograms kg-1 b.w. IV), and Escherichia coli endotoxin (an I1-1 inducer; 0.1 micrograms kg-1 b.w. IV). Although IFNs are considered to be species specific, human IFN-alpha 2a was very potent in dwarf goats. All 3 stimuli induced the 'acute phase response'. Among the varied physiological alterations, which together produce this response, are fever and depression, inhibition of gastric function, tachycardia, a decrease in serum alkaline phosphatase activity, leukopenia, lymphopenia and neutropenia followed by neutrophilic leukocytosis, hypoferraemia and hypozincaemia. The results suggest that, apart from I1-1, IFN-alpha also seems to mediate the systemic 'acute phase response' to certain exogenous stimuli.

Animals↗
PubMed1989

Has bovine somatotropin (BST) an effect upon drug disposition? Comparative studies in goats and cattle with sulphadimidine and antipyrine after parenteral administration of BST, zeranol and proligestone.

Daily subcutaneous BST injection in lactating cows, bulls and castrated male dwarf goats did not induce significant changes in the pharmacokinetic parameters of antipyrine (AP) and sulphadimidine (SDD). Similarly, no changes were obtained after injection of slow-release BST formulations in lactating cows and non-lactating female goats. In contrast to androgenic hormones, both zeranol and proligestone had no effect upon the disposition of AP and SDD, although both synthetic hormones did induce enhanced plasma somatotropin concentrations. In goats, metabolic effects induced by zeranol and BST included significant reductions in plasma urea values, whereas plasma creatinine levels were somewhat lower after daily BST administration.

Animals↗
PubMed1989

[Histochemical changes in skeletal muscles of racehorses susceptible to rhabdomyolysis after exertion. I. Early myopathological changes].

In this communication, the results of an enzyme histochemical study on m. gluteus medius of horses, sensitive to exertional myopathy, during attacks of rhabdomyolysis are presented. The activity and location of about 25 enzymes were examined. In the present report, the early metabolic changes are discussed. Within 6 min after an attack, some large rounded fibres (approximately 2%) were seen, which showed an intense red staining in the haematoxylin and eosin sections. These hypercontracted fibres showed an increase in activity of mitochondrial adenosine triphosphatase, indicating the presence of uncoupling and/or loose coupling of the mitochondria. This finding may point to a deficient production of ATP in the m. gluteus medius of horses sensitive for exertional myopathy and this deficiency may lead to pathological alterations in the skeletal muscles. The pathological fibres revealed a changed activity of other mitochondrial enzymes as well.

Animals↗
PubMed1989

[Histochemical changes in skeletal muscles of racehorses susceptible to rhabdomyolysis after exertion. II. Later myopathological and regeneration phenomena].

Needle biopsies from m. gluteus medius of 22 horses which had suffered from repeated attacks of exertional myopathy were studied at various times after an attack, to determine if metabolic alterations can be demonstrated by enzyme histochemistry. Morphological changes and activity of 25 enzymes were studied. Immediately after onset of an attack, some large rounded fibres with a defect of the oxidative phosphorylation were seen. After some hours these fibres lost their glycolytic enzyme activity, followed by disappearance of mitochondrial enzyme activity with accumulation of Ca2+-containing substances. After 16 h inflammatory cells were found in and around necrotic fibres with a strong activity of acid phosphatase and of the 2 oxidative enzymes of the pentose phosphate pathway. The 4th d after onset of the myopathy regenerating fibres could be observed with a strong activity of both NADPH-producing enzymes of the pentose phosphate pathway. The activity of the decarboxylating enzymes NADP+-malate dehydrogenase and NADP+-isocitrate dehydrogenase was increased in these fibres as well. After some month the studied skeletal muscles were completely normal again. Metabolic interpretations based on the histochemical findings are discussed and compared with those given in literature.

Animals↗
PubMed1988

Effect of feeding 5 per cent glucose solution or milk replacer to newborn piglets on intestinal permeability to macromolecules.

Newborn piglets were fed either a 5 per cent glucose/electrolyte solution or a commercial milk replacer for 24 or 36 hours before they were given colostrum, or they were given colostrum after birth. The effects of these treatments on their ability to absorb macromolecules was assessed by measuring the uptake of 125I-polyvinylpyrrolidone (125I-PVP) and the increases in the concentrations of total proteins and immunoglobulins in serum. The piglets which received colostrum at birth absorbed 50 per cent of a test dose of 125I-PVP within six hours, and there was a rapid increase in the concentration of immunoglobulins in their blood. The piglets which received the 5 per cent glucose/electrolyte solution absorbed 40 per cent of the test dose of 125I-PVP administered 24 or 36 hours after birth and nearly normal quantities of immunoglobulins, but the piglets given the milk replacer absorbed only 10 per cent of the test dose of 125I-PVP, and virtually no immunoglobulins.

Animal Feed↗
PubMed1988

[Potassium ion concentration in the vitreous body as an indicator of the postmortem interval in cattle].

Reliability and accuracy of the vitreous potassium concentration as an indicator of the post-mortem interval (PMI) in cattle were studied. Sampling not more than 1 ml of vitreous humor from the centre of the corpus vitreum was found to improve both accuracy and reliability. A significant correlation between the PMI and the vitreous potassium concentration was found to be present in cattle.

Animals↗
PubMed1988

Intestinal permeability to macromolecules during colibacillosis in piglets.

Intestinal macromolecular permeability to macromolecules was determined in a group of specific pathogen free piglets before and after they were infected experimentally with Escherichia coli. Six hours after the infection all piglets developed a profuse diarrhoea. The urea and total protein concentrations in the serum increased markedly after the onset of diarrhoea. Haemoglobin concentration and PCV decreased steadily during the experiment but blood glucose concentration and lipid composition of the faeces did not change. No structural abnormalities in the jejunal and ileal mucosa were seen. No uptake of macromolecules (40,000 KDa) was found suggesting that molecules with a molecular weight of 40,000 or more do not play a role in the persistent diarrhoea sometimes seen in piglets after colibacillosis.

Animals↗
PubMed1988

Intestinal permeability to macromolecules in piglets infected with transmissible gastroenteritis virus.

The permeability of the intestine of specific pathogen free piglets was investigated by measuring the concentration of 125-I in the blood after oral administration of 125-I polyvinylpyrrolidone (125-I PVP, MW = 40,000 Da) and the concentration of 131-I in the faeces after intravenous administration of 131-I porcine albumin (131-I PA, MW = 68,000 Da). The tests were performed one day before and up to two days after the piglets were infected with the Miller strain of transmissible gastroenteritis (TGE) virus. Biopsies of the jejunum were taken at the end of the experiment and blood samples were taken six-hourly. The piglets became anorexic and had diarrhoea 12 hours after infection; the packed cell volume decreased and the concentrations of urea and total serum proteins increased slightly after infection. However, the marked villous atrophy was not accompanied by an increased permeability of the intestine to PVP or PA.

Albumins↗