Biomedical subjects
Publications and source records attributed to A A Lubberink.
On the occasion of his retirement as an active specialist in Surgery dr. P.H.A. Poll describes the history of the development of the specialties in Veterinary Medicine in The Netherlands and carefully looks forward. As a tribute, his specialist colleagues, all related to the Companion Animal Hospital "De Wagenrenk", publish one or more case reports from there respective disciplines (ophthalmology, surgery, radiology, dermatology).
This paper describes four cats with hyperadrenocorticism. Cat 1 showed polydipsia and polyphagia. Diabetes mellitus was initially diagnosed. As the animal appeared to be insulin resistant, pituitary and adrenocortical function tests were performed and the diagnosis of hyperadrenocorticism was made. Resistance to the high-dose dexamethasone suppression test was noticed in this cat. Pathological examination revealed a pituitary chromophobe adenoma. Cat 2 presented with diabetes mellitus, which was treated with insulin. The animal had a pendulous abdomen and its coat was in a poor condition. The low-dose dexamethasone suppression test demonstrated hyperadrenocorticism. Necropsy findings of pituitary tumour and hyperplasia of the adrenal cortex confirmed the diagnosis. Cat 3 showed clinical abnormalities indicative of hyperadrenocorticism, for instance, muscle weakness, alopecia, multiple abscesses. The diagnosis of hyperadrenocorticism was confirmed by the results of the lowe-dose dexamethasone suppression test. Pathological examination revealed an adrenocortical carcinoma. Cat 4 presented with polydipsia. The cause of this symptom was not found initially. One and a half years later additional symptoms, such as nephritis and polyphagia developed. Hyperadrenocorticism was diagnosed because of a palpable mass cranial to the left kidney. The diagnosis was confirmed by the results of the lowe-dose dexamethasone suppression test and the necropsy findings.
In six normal dogs the adrenals could be visualized as separate areas of radioactivity at 7--10 days after injection of 20--40 muCi 131I-iodocholesterol per kg of body weight. Image analysis revealed uptake values of 0.15--0.3% of the injected dose. In five dogs with pituitary-dependent hyperadrenocorticism the adrenals became visible at 3--5 days after injection of the radiopharmaceutical, with uptake values of 0.38--2.2%. In six dogs with hyperadrenocorticism due to adrenocortical tumor the scintigraphy contributed to the diagnosis and the presurgical localization. The uptake values were within the normal range; the tumor could be observed at 3--10 days after injection. Additional findings on adrenal asymmetry and a case of fluctuating pituitary-dependent hyperadrenocorticism are discussed.
The response has been studied in nine dogs with hyperadrenocorticism due to adrenocortical tumours to the administration of dexamethasone, insulin, lysine-vasopressin and tetracosactide by measuring the changes in plasma cortisol concentration. Administration of dexamethasone did not produce a decrease in the plasma concentration of cortisol in any of these dogs. Administration of insulin caused slight increases in the plasma concentration of cortisol in four out of eight dogs. Lysine-vasopressin increased the plasma concentration of cortisol in eight out of nine dogs, three responded supranomally. Eight out of the nine dogs responded to tetracosactide administration, three responded supranormally, It is concluded that in the dog, in contrast to man, the lysine-vasopressin test cannot be used to differentiate between pituitary-dependent hyperadrenocorticism and hyperadrenocorticism due to an adenocortical tumour. Apparently pituitary ACTH is not completely depleted in dogs with hyperfunctioning adrenocortical tumours.
An 11-year-old spayed cat was presented with clinical signs suggestive of hyperadrenocorticism. Adrenocortical function was assessed by dexamethasone suppression and by stimulation with ACTH and the results provided a tentative diagnosis of adrenocortical tumour. Via laparotomy (paracostal approach), the enlarged right adrenal gland was removed. Histopathological diagnosis was adrenocortical adenoma.
The use of cryosurgery in treatment of eosinophilic granuloma in cats is described. Satisfactory results were obtained in 14 of 19 cats and 4 of the 5 cats which did not respond favorably, had multiple lesions. The simplicity of the technique and the rapidity of healing make cryosurgery a useful alternative to previous methods of treatment.
Gamma camera imaging of the adrenal glands was done in 8 dogs with hyperadrenocorticism and 4 normal dogs given intravenous injections of 131I-19-iodocholesterol. In normal dogs, both adrenal glands could be visualized separately, and there was no difficulty in distinguishing among the images of normal glands, hyperplastic glands, and functional adrenal tumors. In addition, gamma camera imaging enabled the correct surgical site to be selected for removal of adrenal tumors. Hyperadrenocorticism was diagnosed in 8 dogs by evaluation of urinary 17-hydroxycorticosteroid (OHCS) excretion rates, urinary 17-OHCS and plasma 11beta-OHCS RESPONSES TO DEXAMETHASONE SUPPRESSION OF ENDOGENOUS ADRENOCORTICOTROPIN (ACTH) secretion, and plasma 11beta-OHCS response to intravenous administration of ACTH. Base line 17-OHCS excretion increased in 5 of the 8 dogs. Plasma 11beta-OHCS concentrations were not decreased by dexamethasone administration in the 4 dogs subsequently found to have adrenal tumors; however, there was an exaggerated increase in plasma 11beta-OHCS concentration after administration of ACTH in 3 of the 4 dogs which had bilateral adrenocortical hyperplasia.