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Biomedical subjects

A H van den Broek

Publications and source records attributed to A H van den Broek.

17 recordsLinked to original sources
PubMed2000

Cutaneous and systemic responses during primary and challenge infestations of sheep with the sheep scab mite, Psoroptes ovis.

Lesional area was estimated and lesional mast cells and eosinophils were counted during primary and challenge infestations of sheep with Psoroptes ovis. In addition, circulating basophils and eosinophils and serum P. ovis-specific immunoglobulin IgE antibody were quantified. Expansion of lesional area was significantly less and serum IgE titres significantly greater in challenge than primary infestations. Lesional mast cell hyperplasia and massive eosinophil infiltration accompanied by raised titres of P. ovis antigen-specific IgE antibody were compatible with an IgE-mediated Type-1 allergic reaction, while detection of lesional basophils was suggestive of cutaneous basophil hypersensitivity. The temporal pattern of lesional mastocytosis and eosinophil infiltration and the role of these cells and serum IgE in the immune response is discussed.

Animals↗
PubMed1998

Retrospective survey of allergen immunotherapy in canine atopy.

The clinical records of 277 cases of canine atopy treated with specific allergen immunotherapy were reviewed. A good response was defined as control with immunotherapy either alone or with topical agents, a partial response as control with immunotherapy and other systemic agents, and a poor response as no perceived benefit and the immunotherapy discontinued. The mean follow-up period was 29.2 months (range 10 to 85 months). Ninety-one cases (33 per cent) were lost to follow-up or failed to comply with the therapeutic protocol. Of the remaining 186 cases, 40 (21.5 per cent) had a good response to immunotherapy, 74 (39.8 per cent) had a partial response, and 72 (38.7 per cent) had a poor response. Immunotherapy was therefore of long-term benefit in 114 dogs (61.3 per cent). No significant differences in response rates were associated with the breed or sex of the dog, or the age of onset of the disease, or with the type or number of allergens included in a vaccine. Dogs which had clinical signs for more than 61 months before immunotherapy had a significantly poorer response rate (23.5 per cent, P < 0.05). In-house cases had a significantly better response rate (95.2 per cent, P < 0.05) than externally managed cases.

Allergens↗
PubMed1995

Canine atopic disease: the prevalence of positive intradermal skin tests at two sites in the north and south of Great Britain.

Results of intradermal skin test responses to the same panel of 53 allergens were compared in 118 dogs with atopic disease presented at two geographical centres, Edinburgh (87 cases) and London (31 cases). The allergens most commonly positive at both centres were human dander and Dermatophagoides farinae, but positive tests to all of the allergens used occurred in at least one case. The mean number of allergens to which positive tests resulted in atopic dogs was 5.126 (Edinburgh) and 5.129 (London). The majority of animals were sensitive to allergens from more than one group. A significantly higher number of positive reactors to house dust allergen was observed at London than at Edinburgh (P < 0.05), while a significantly higher number of positive reactions to grass pollens was detected at Edinburgh than in London (P < 0.05). Sensitivity to Dermatophagoides pteronyssinus, in the absence of sensitivity to D. farinae, was uncommon and therefore both of these mite allergens should be incorporated in intradermal skin testing panels in Great Britain.

Animals↗
PubMed1993

A standardized oral zinc tolerance test for assessment of zinc absorption in dogs.

Three oral zinc tolerance tests using increasing doses of elemental zinc (0.5, 0.75 and 1.0 mg/kg) given as zinc sulphate (ZnSO4.7H2O) were carried out in eight normal beagles. The zinc tolerance curves obtained were similar to those described in man, with the peak plasma zinc concentration occurring 2 h after dosing. There was a considerable variation between individual animals in the peak plasma zinc concentration achieved with each dose. This would appear to limit the value of a zinc tolerance test in assessing the efficiency of zinc absorption in individuals, although it may be of value in making comparisons between groups of dogs.

Administration, Oral↗
PubMed1992

Epidermal and hepatic glucocorticoid receptors in cats and dogs.

Low capacity, high affinity [3H] dexamethasone binding receptors were identified in cytosolic preparations of liver (mean number 45 +/- 10.1 fmol mg-1 protein, apparent dissociation constant 0.4 +/- 0.1 nM) and skin (mean number 46.4 +/- 23.8 fmol mg-1 protein, apparent dissociation constant 1 +/- 0.2 nM) of clinically normal dogs. For clinically normal cats, approximately half these numbers of receptors with a lower affinity, were detected in liver (mean number 23.1 +/- 10.4 fmol mg-1 protein, apparent dissociation constant 3.2 +/- 0.9 nM) and skin (mean number 23.90 +/- 10.9 fmol mg-1 protein, apparent dissociation constant 2.2 +/- 1.5 nM). This difference between dogs and cats in [3H] dexamethasone binding receptors may contribute to the relative glucocorticoid resistance observed in cats.

Animals↗
PubMed1992

Fat absorption in dogs with demodicosis or zinc-responsive dermatosis.

Quantitative absorption of long-chain triglycerides was studied in normal dogs, dogs with demodicosis and dogs which had been successfully treated for zinc-responsive dermatosis. The mean serum triglyceride concentration of dogs treated for zinc-responsive dermatosis was significantly lower than that of normal dogs before (P less than 0.01) and at one hour (P less than 0.01) and two, three and four hours (P less than 0.001) after feeding vegetable oil. No significant difference was detected in the mean serum triglyceride concentration of dogs with demodicosis and normal dogs at any of the sampling times.

Absorption↗
PubMed1991

Epidermal dexamethasone receptors in dogs with confirmed hyperadrenocorticalism, hypothyroidism or undiagnosed hormonal alopecia.

Low capacity, high affinity [3H] dexamethasone binding receptors were identified in cytosolic preparations of the skin (mean number 42.0 +/- 25.2 fmol mg-1 protein, apparent dissociation constant (1 nM +/- 0.23) of clinically normal dogs. No [3H] dexamethasone binding was observed in the skin of nine out of 10 dogs with confirmed spontaneous hyperadrenocorticism or in the skin of three out of six dogs with undiagnosed hormonal alopecia. A reduction was detected in the number of [3H] dexamethasone binding receptors in the skin of one dog with confirmed hypothyroidism. This study provides evidence for the susceptibility of canine glucocorticoid receptors to down regulation by imbalances of endogenous hormones, particularly increased glucocorticoid concentrations.

Adrenocortical Hyperfunction↗
PubMed1991

Fat absorption in dogs with diabetes mellitus or hypothyroidism.

Quantitative fat absorption was studied in normal dogs and in dogs with hypothyroidism and diabetes mellitus. The serum triglyceride concentrations of diabetic and hypothyroid dogs were significantly higher at each sampling time than those of normal dogs. The fat absorption curve of hypothyroid dogs peaked at 180 minutes and though significantly raised was parallel to that of normal dogs whereas the fat absorption curve of diabetic dogs continued to rise up to 240 minutes. These results provide evidence for impaired plasma clearance of triglyceride in canine diabetes mellitus and hypothyroidism.

Absorption↗
PubMed1990

Assessment of fat absorption in normal dogs and in dogs with hyperadrenocorticalism.

Fat absorption was determined quantitatively in clinically normal dogs, dogs with confirmed hyperadrenocorticalism before and after treatment with mitotane (op' DDD) and in pruritic dogs before and after administration of prednisolone. Fat absorption was significantly higher (P less than 0.001) in dogs with untreated hyperadrenocorticalism and pruritic dogs on prednisolone therapy than in normal dogs. It was normal in pruritic dogs before prednisolone therapy and approached normality in dogs with treated hyperadrenocorticalism. It is concluded that high circulating cortisol or prednisolone levels result in increased intestinal absorption of dietary fat possibly mediated by increased glucocorticoid induced activity of enterocytes or reduced hepatic clearance of triglycerides.

Adrenocortical Hyperfunction↗
PubMed1989

Serum protein electrophoresis in spontaneous canine hyperadrenocorticalism.

The serum protein concentrations of dogs with confirmed spontaneous hyperadrenocorticalism were determined by agarose gel electrophoresis before and during treatment with mitotane. In untreated animals a significant increase was detected in the mean concentration of total protein and the mean concentration and percentage of alpha-2 globulin. The mean concentration and percentage of albumin and gamma-globulin were significantly decreased. In animals on treatment the mean concentration of total proteins and the mean concentration and percentage of beta-2 globulin were significantly reduced.

Adrenal Cortex Diseases↗
PubMed1988

Diagnostic value of zinc concentrations in serum, leucocytes and hair of dogs with zinc-responsive dermatosis.

The concentrations of zinc in serum, leucocytes and hair of normal dogs, dogs with zinc-responsive dermatosis and dogs with dermatitis not associated with zinc deficiency was determined. The mean concentration of zinc in serum and hair of dogs with zinc-responsive dermatosis was significantly lower than in other dogs but the range of zinc concentrations overlapped that of the other dogs. The mean leucocyte zinc concentration was similar for each group of dogs. It is concluded that low zinc concentrations in serum and hair have only a corroborative value in the diagnosis of zinc-responsive dermatosis in dogs.

Animals↗
PubMedDate not supplied

Serum protein electrophoresis in canine parvovirus enteritis.

The serum protein concentrations of dogs with confirmed canine parvovirus enteritis were determined by agarose gel electrophoresis before treatment. A significant decrease was detected in the mean concentration and percentage of albumin and gammaglobulin and the percentage of alpha-1-globulin. The mean concentration and percentage of alpha-2-globulin were significantly increased.

Animals↗