Biomedical subjects
Publications and source records attributed to J Bucek.
Ultrastructural characteristics of four mixed-cell type human uveal melanomas cultivated in vitro were described. The authors stress the significance of melanosome microtubules in the process of melaninisation. They also stress the significance of smooth membraness for the formation of premelanosomes. The question of differentiation between melanocytes and lysosomes in ultrastructure is discussed.
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Non-specific esterase, acid phosphotase, beta-glucoronidase, and N-acetyl-beta-glucosamindase were revealed using the histochemical method of asocombinations in biopsy specimens of the muscular tissue taken from 99 patients suffering from neurogenic and myogenic disorders. Biopsy specimens were taken also from 7 healthy persons. Concentrations of the granular product of the reaction correlated with autofluorescence in the same section. Some bioptic materials were investigated using electron-microscopy. It was established that activity of lysosomal hydrolases in the normal muscular tissue was low, being increased with age. Autofluorescence in the majority of cases was well noticible. In the groups of atrophic fibres in neurogenic atrophy there were observed focal elevation of the lysosomal enzymatic activity. Product of the reaction, which pointed to the activity of nonspecific esterase and acid phosphotase, was localized predominantly along the periphery of muscular fibres. Autofluorescence of the product of the reaction was considerable. On the other hand, there were extensive areas of muscular fibres in which the concentration of the reaction product did not exceed the normal level. Activity of hydrolases in cells of the mesenchyma was of a low degree. Ist type of the lysosomal activity was observed in myogenic dystrophy with an acute course of the disease; it was characterized by structural changes in the muscular tissue, activation of the all hydrolases under study, absence of autofluorescence on the areas of localization of the reaction product, participation of the mesenchyma cells in the lysosomal activation. IInd type of the lysosomal activity was noted in the muscular tissue in neurogenic atrophy. There was no difference in principle between neuro- and myogenic lesions as far as the type of lysosomal activity is concerned. Collation of the results obtained in the investigations with the data reported in available literature enabled the authors to put forward the concept of the two types of the lysosomal activity in muscular lesions: 1) diffuse elevation of the lysosome activity associated with structural changes in the muscular tissue; 2) focal elevation of the physiological activity due to formation of lipopigment.
In four renal biopsies of two patients with chronic glomerulonephritis (GN), the so-called dense deposit nephropathy (NDD) was diagnosed by means of light, electron, and immunofluorescence microscopy. In routine paraffin sections the picture approached that of the membrano-proliferative GN. In semithin sections (toluidine blue, periodic acid-Ag-methenamine) and especially in the ultrastructure there appeared extensive confluent deposits of a very dense substance, infiltrating the lamina densa of glomerular capillaries, basal membranes of both Bowman's capsules and tubules, and arteriolar walls. In this localization, a non-diffuse "psdudolinear" deposition of beta1c was detected, whereas antisera to main Ig-fractions and fibrin(ogen) were not fixed. In a biopsy performed six years later, a concentration of dense depositis towards the mesangial area and a partial regeneration of basal membranes were observed. In a part of dense deposits there appeared vacuolization, primarily in tubular and arteriolar basal membranes. In glomeruli, focal IgM deposits were apparent at an advanced stage. NDD apparently is a sequel of a particular metabolic (immune?) process, afflicting solely the renal membranous system and distinctly dns known at present. The noncharacteristic clinical presentation resembles chronic. GN, is very protracted, lengthy, and relatively benigh, with a chance of functional and possible even morphological remission.
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