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Biomedical subjects

T Wensing

Publications and source records attributed to T Wensing.

At least 19 recordsLinked to original sources

[Toxicity of cadmium in cattle].

After having investigated the metabolism of cadmium in plants and animals, the Animal Health Service of North Brabant in 1982 instigated research into the level of cadmium in the livers and kidneys of beef cattle kept in the vicinity of a zinc processing factory. Cadmium levels in these cattle were more than twice as high as those of cattle kept in control areas. Clinical abnormalities as a result of the increased cadmium levels were not observed, although haemoglobin and iron levels, iron-binding capacity and iron saturation were lower in these animals than in control animals. Cadmium therefore appears to have an adverse effect on iron absorption. Administration of high doses of cadmium for a limited period to 14 heifers did not cause discernable clinical abnormalities. These animals retained cadmium to a much smaller extent than anticipated on the basis of data for monogastric (mainly rats) animals.

Animals

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

Effect of ileo-rectal anastomosis and post-valve T-caecum cannulation on growing pigs. 2. Blood variables and mineral balances.

In a long-term study nine ileo-rectally anastomosed (IRA) and seven post-valve T-caecum (PVTC)-cannulated pigs were compared with six intact pigs with regard to different blood variables, sodium and potassium retention and weights of selected organs. After surgery, apart from urea and K measured 13 weeks post-surgery, there were no differences in the blood variables between the PVTC-pigs and intact pigs. In IRA-pigs concentrations of creatinine (P < 0.01), Na (P < 0.001), base excess (P < 0.001), pH (P < 0.01) and bicarbonate (P < 0.001) in blood were lower than those in intact pigs. At 13 weeks after surgery the blood K concentration in IRA-pigs was higher (P < 0.001) than that in PVTC-pigs or intact pigs. At 6 weeks after surgery the blood urea concentration in IRA-pigs was higher (P < 0.001) than that in intact and PVTC-pigs. At 13 weeks after surgery the urea concentration in PVTC-pigs was higher (P < 0.001) than those in IRA-pigs or intact pigs. The Na (P < 0.01 11 weeks after surgery) and (P < 0.05 and P < 0.01 5 and 11 weeks after surgery respectively) balances in IRA-pigs were lower than those in intact animals. Na retention was negative for IRA-animals 11 weeks after surgery. Na and K retentions were similar in PVTC-pigs and in intact pigs. The urinary: faecal excretion of Na differed slightly between PVTC-animals and intact animals. At 13 weeks after surgery there were no differences in organ weights between the PVTC-pigs and intact animals. In the IRA-pigs the weights of the liver (P > 0.05), the kidneys (P > 0.05) and the adrenal glands were higher (P < 0.001) than those in the intact animals.

Adrenal Glands

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

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

The effect of T. vivax infection in west African dwarf goats on energy and nitrogen metabolism.

To investigate how T. vivax affects metabolism in dwarf goats, nine wethers (infection group) given alfalfa pellets ad libitum were infected intravenously and food intake was recorded up to 49 days after infection in the infection group and in the control group (n = 9). Controls received the same diet, ad libitum before infection and in restricted amounts after infection in order to obtain similar intakes in the two groups. Digestible organic matter intake (DOMI) and nitrogen balance (NB) were determined during four balance trials. All animals were bled regularly to measure parasitaemia, packed cell volume (PCV) and a number of serum metabolites. All infected animals showed symptoms typical for T. vivax infection as judged by parasitaemia, PCV and rectal temperature. Infection had a non-uniform negative effect on food intake. Compared with controls at equal DOMI, NB was lower in infected animals, the difference being significant 4 weeks after infection. This was caused by a gradual increase in NB at equal DOMI of the control group. The NB of the ad libitum fed infected animals 2 and 4 weeks after infection was comparable to values normally found in healthy ad libitum fed dwarf goats with an equal DOMI. NEFA values in serum were significantly elevated after infection. Except for two infected animals with an extremely low food intake towards the end of the experiment, no rise in serum ketone bodies was evident. After infection, serum protein increased, differences with controls being significant 4 and 7 weeks after infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed

Hepatic lipidosis in pregnant cows on a dairy farm.

A syndrome very similar to hepatic lipidosis is described in dairy cows during the dry period. After being sent to pasture the animals did not eat well for undetermined reasons. The disease phenomena were mainly observed in animals carrying twins. At post mortem examination severe falty infiltration was found in the 3 animals made available for post mortem examination. Increase of the energy supply to the dry cows by addition of maize silage to the ration prevented new cases.

Animals

Fever and acute phase response induced in dwarf goats by endotoxin and bovine and human recombinant tumour necrosis factor alpha.

Tumour necrosis factor (TNF), a polypeptide produced by mononuclear phagocytes, has been implicated as an important mediator of inflammatory processes and of clinical manifestations in acute infectious diseases. To study further the potential role of TNF in infectious diseases, recombinant Escherichia coli (E. coli) derived human (r.HuTNF-alpha) and bovine TNF (r.BoTNF-alpha) were intravenously (i.v.) administered in dwarf goats. Rectal temperature, heart rate, rumen motility, plasma zinc and iron concentrations, and certain other blood biochemical and haematological values were studied and compared with the changes seen after E. coli endotoxin (LPS) was administered (dose: 0.1 microgram/kg i.v.). Following a single injection of 4 micrograms/kg of r.BoTNF-alpha, shivering and biphasic febrile response were observed, accompanied by tachycardia, inhibition of rumen contractions, drop in plasma zinc and iron concentrations, lymphopenia, and neutropenia followed by neutrophilia. The i.v. administration of a single injection of 4 micrograms/kg r.HuTNF-alpha induced shivering and biphasic febrile responses, accompanied by anorexia and a similar drop in plasma trace metal concentrations when compared with r.BoTNF-alpha-treated goats. The TNF-alpha-induced symptoms were essentially the same as those that occurred after LPS administration. However, the time of onset of these changes after the injection of TNF-alpha was significantly shorter than after LPS. Moreover, the r.BoTNF-alpha induced a longer lasting neutrophilic leucopenia, less neutrophilia, and a more persistent lymphopenia than after LPS injection. Neither r.BoTNF-alpha nor LPS caused severe haemo-concentration. Furthermore, no cross-tolerance between r.BoTNF-alpha and LPS could be demonstrated. We conclude that both r.BoTNF-alpha and r.HuTNF-alpha induce many of the physiologic, haematologic and metabolic changes that characterize the acute phase response to LPS. The overlapping biological activities of r.BoTNF-alpha, r.HuTNF-alpha and LPS in dwarf goats may indicate that both recombinant tumour necrosis factors have some homology with caprine TNF-alpha.

Acute-Phase Reaction

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

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

Analgesic and spasmolytic effects of dipyrone, hyoscine-N-butylbromide and a combination of the two in ponies.

The analgesic and spasmolytic effects of dipyrone (Novalgin) (2500 mg/100 kg bodyweight) hyoscine-N-butylbromide (Buscopan) (20 mg/100 kg bodyweight) and a combination of both drugs were evaluated in a balloon-induced model of colic, using five ponies with caecal fistulae. The drugs were given intravenously and 0.9 per cent sodium chloride solution (5 ml/100 kg bodyweight) was used as a control. The physiological saline solution and dipyrone had no effect on caecal contractions. After the injection of hyoscine-N-butylbromide and the drug combination caecal contractions ceased within 30 seconds and for 20 and 24 minutes, respectively (P less than 0.05). The results on pain relief were not statistically significant for any of the drugs. Dipyrone had a good analgesic effect in only two of the ponies, starting after eight to 10 minutes and lasting for 50 minutes. The drug combination relieved pain within 30 seconds after injection and the relief lasted for 50 minutes in three of the ponies and for 20 minutes in the other two. Hyoscine-N-butylbromide alone produced an analgesic effect within 30 seconds after injection which lasted for 20 minutes.

Analgesia

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

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

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

Experimental induction of fasting hypoglycaemia and fatty liver syndrome in three Yorkshire terrier pups.

Eight hours fasting in Yorkshire terrier pups resulted in marked variation of blood glucose, showing both hypo- en hyperglycaemia. Prolonged fasting in three Yorkshire terrier pups resulted in hypoglycaemia with concomitant ketosis and steatosis of the liver. The hypoglycaemia was associated with decreasing insulin and increasing glucagon and cortisol levels. This is in contrast to fasting adult dogs, which maintain glucohomeostasis and show only slightly decreased insulin levels, normal glucagon levels and a moderate increase of plasma ketone bodies. The reaction to an eight hour fasting period in the Yorkshire terrier pups is thought to be related to inadequate gluconeogenesis and diminished insulin production and/or release. The different reaction to prolonged fasting, compared to adult dogs and pups of larger breeds, seems related to inadequate gluconeogenesis and results in hypoglycaemia, a ketogenic hormonal setting and steatosis of the liver. Frequent feeding of a high-energy, protein-rich diet to both mother and pups may prevent toy-breed pups from developing hypoglycaemia and may help them to overcome periods with a decreased intake of energy.

Animals

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