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Biomedical subjects

A M van Dongen

Publications and source records attributed to A M van Dongen.

10 recordsLinked to original sources

Evaluation of canine COL4A3 and COL4A4 as candidates for familial renal disease in the Norwegian elkhound.

The collagen type IV alpha3 and alpha4 chains (COL4A3 and COL4A4) are part of the specialized glomerular basement membrane in the kidney. In human these genes are responsible for Alport syndrome (a type of hereditary nephritis). Histopathological similarities between kidneys of Norwegian elkhound dogs affected with familial renal disease and human Alport syndrome were the basis for a candidate gene approach in Norwegian elkhounds. Three microsatellites-tightly linked to canine COL4A3 and COL4A4--were developed. The microsatellites were used to analyze linkage between COL4A3 and COL4A4 and familial renal disease in a Norwegian elkhound pedigree segregating this disease. Presence of one recombinant between familial renal disease and COL4A3/COL4A4 suggests that these genes are not likely candidates for familial renal disease in this breed.

Age of Onset↗

Primary hyperaldosteronism, a mediator of progressive renal disease in cats.

In recent years, there has been renewed interest in primary hyperaldosteronism, particularly because of its possible role in the progression of kidney disease. While most studies have concerned humans and experimental animal models, we here report on the occurrence of a spontaneous form of (non-tumorous) primary hyperaldosteronism in cats. At presentation, the main physical features of 11 elderly cats were hypokalemic paroxysmal flaccid paresis and loss of vision due to retinal detachment with hemorrhages. Primary hyperaldosteronism was diagnosed on the basis of plasma concentrations of aldosterone (PAC) and plasma renin activity (PRA), and the calculation of the PAC:PRA ratio. In all animals, PACs were at the upper end or higher than the reference range. The PRAs were at the lower end of the reference range, and the PAC:PRA ratios exceeded the reference range. Diagnostic imaging by ultrasonography and computed tomography revealed no or only very minor changes in the adrenals compatible with nodular hyperplasia. Adrenal gland histopathology revealed extensive micronodular hyperplasia extending from zona glomerulosa into the zona fasciculata and reticularis. In three cats, plasma urea and creatinine concentrations were normal when hyperaldosteronism was diagnosed but thereafter increased to above the upper limit of the respective reference range. In the other eight cats, urea and creatinine concentrations were raised at first examination and gradually further increased. Even in end-stage renal insufficiency, there was a tendency to hypophosphatemia rather than to hyperphosphatemia. The histopathological changes in the kidneys mimicked those of humans with hyperaldosteronism: hyaline arteriolar sclerosis, glomerular sclerosis, tubular atrophy and interstitial fibrosis. The non-tumorous form of primary hyperaldosteronism in cats has many similarities with "idiopathic" primary hyperaldosteronism in humans. The condition is associated with progressive renal disease, which may in part be due to the often incompletely suppressed plasma renin activity.

Adrenal Glands↗