Giant mitochondria in "zero-hour" transplant biopsies.

Giant mitochondria in kidneys have increasingly been observed since the introduction of Cyclosporin A (CSA) as immunosuppressant in kidney transplants and in patients with autoimmune disorders. In animals treated with CSA, giant mitochondria were also described. In a study of "zero-hour" biopsies taken immediately before or after reperfusion of the renal transplant, giant mitochondria were often unexpectedly found. Retrospective analysis revealed that a significant increase in the number of giant mitochondria is more often associated with CSA therapy than ischemia. Giant mitochondria with sparse cristae seem to prevail in ischemia, whereas those with dense matrix and crystalloid structures predominate in CSA therapy.

Morphologic findings in "zero-hour" biopsies of renal transplants.

The extreme lack of renal grafts for transplantation stimulated us to analyze how strict the selection criteria of kidney donors must be. We investigated therefore if preexisting lesions in renal grafts influence initial and late renal function. 147 zero-hour biopsies of 101 donors (mean age 33, from 6-64 years) were examined. By ligh microscopy 38% of biopsies showed no, 44% showed nonspecific and 18% specific lesions. Nonspecific lesions comprised intimal fibrosis of small arteries in 44%, interstitial fibrosis in 8% and an arteriolar hyalinosis in 29%. Out of 102 immunohistologically examined biopsies 74.5% showed nonspecific IgM/C3 deposits in glomeruli and/or arterioles. An age dependent decrease of normal renal biopsies was found which was most evident in donors older than 40 years. Specific findings consisted of glomerulosclerosis (n = 4), glomerulonephritis (n = 11), intravascular coagulation (n = 10) and eclamptic kidney (n = 1). In case of nonspecific immunohistologic findings and in glomerulonephritis rebiopsies showed that antigen deposits usually disappeared within 4 months. Independent of morphologic findings 82% of transplant recipients had a good initial and late renal function. Since donor age, glomerulosclerosis, glomerulonephritis, intravascular coagulation or eclamptic changes seem not to compromise renal function after transplantation a more liberal choice of donors should be considered.

Collagen type III glomerulopathy: a new idiopathic glomerular disease.

A new type of idiopathic glomerular disease is reported in a 49-year-old Italian woman who presented with uncharacteristic renal symptoms, i.e., hypertension and slight proteinuria. Clinical investigation excluded a familial renal disease and more specifically nail-patella syndrome. Diagnostic renal biopsy by light microscopy showed a picture similar to membranoproliferative glomerulonephritis. The enlarged glomeruli were lobulated, the peripheral basement membranes were thickened by the deposition of light-microscopically undefined material, cell proliferation was lacking. By electron microscopy, the material was nonhomogenous, partly granular partly fibrillar, containing typical collagen fibers. The latter were identified as collagen type III, to a lesser extent collagen type I. Review of the literature resulted in 12 similar or identical cases reported from Japan and one additional case reported in a white American female. Evidence of systemic disease is lacking. Etiology and pathogenesis are elusive. A progressive deterioration of renal function must be expected. Collagen type III glomerulopathy is suggested as term of this new type of idiopathic glomerular disease.

Neuritic plaques in senile dementia of Alzheimer type: a Golgi analysis in the hippocampal region.

Tissue sections from the hippocampal region of patients with senile dementia of Alzheimer type were examined in 75-100 microns thick vibratome sections impregnated by the Golgi-Cox method and counterstained with cresyl violet. The morphology of dendrites and axons with neuritic plaques was frequently abnormal. Abnormalities included pleomorphic outpouchings of terminal and preterminal dendritic and axonal segments, many of which contained filiform processes occurring singly and in tufts. The axon collaterals of some hippocampal neurons appeared to branch richly as they entered plaques. Impregnated neurites could occasionally be traced from a neuritic plaque to adjacent pyramidal and local circuit neurons. The findings confirm that local neurons of different types contribute dendrites and axons to plaques and that these processes may proliferate within the confines of the plaques.