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Biomedical subjects

C Povýsil

Publications and source records attributed to C Povýsil.

10 recordsLinked to original sources
PubMed1979

Ultrastructural evidence of myofibroblasts in pseudomalignant myositis ossificans.

Seven cases of pseudomalignant ossifying myositis with a typical clinical symptomatology have been reported. None of the cases had experienced an injury. All the lesions were intramuscular and all of them showed a zonal arrangement. Electron microscopy in three cases allowed the demonstration of cells showing morphological features of myofibroblasts and monocytic cells of the macrophage type. These previously unreported features together with the zonal pattern of the lesions indicate their reparative nature.

Adolescent↗
PubMed1979

Ultrastructure of benign chondroblastoma.

Electron microscopic examination of three chondroblastomas showed two main cell types, namely pale and dark cells. Multilobulate nuclei characteristic of typical neoplastic chondroblasts were found in both the cell types. Besides differences in cytoplasmic and nuclear density, the cells also differed in nuclear shape and in proportions of various cytoplasmic organelles. Small pale cells resembled prechondroblasts of embryonic cartilage. Large pale cells showed features of chondroblasts. From pale cells of the above type, smooth transitions were observed to the dark cells, possessing dense, less regularly shaped nuclei and typically a larger amount of rough endoplasmic reticulum. Some of the dark cells may represent cells undergoing regressive alterations, but the majority of them seem to represent chondroblasts with imperfect maturation towards chondrocytes. Such findings suggest that benign chondroblastoma is composed of cartilaginous cells with various degrees of differentiation. The finding of occasional cilia is reported.

Cell Differentiation↗
PubMed1979

Cadmium necrosis in transplanted testicles as evidence for persistence of original vessels in the graft.

The testicles of newborn rats were transplanted subcutaneously to the external ears of mature male rats. Four and 8 weeks later the hosts received a subtoxic dose of cadmium chloride. Forty-eight hours thereafter focal, but evidently cadmium-induced necroses occurred in the grafts. As is the generally acknowledged, the tissue selectively sensitive to cadmium is the original endothelium of testicular vessels. Therefore the results of the study can be summarized as follows: 1) In the transplanted testicles the original vessels and their endothelium survive for at least 8 weeks. 2) Under the experimental conditions used here, the original vasculature of the graft joins with the vascular system of the host.

Animals↗
PubMed1977

alpha-D-mannosidase activity in histiocytosis X.

A histochemical study of enzymatic activities was undertaken in five cases of histiocytosis X (two localized bone forms, two generalized forms, and one involving mainly the skin), each of which revealed characteristic structural features at the optical and ultrastructural levels. A confirmation was made of the original assumption of high acid alpha-D-mannosidase activity, i.e. activity described in human Langerhans intraepidermal cells (Elleder, 1975). In the control group of tumors, with the exception of urticaria pigmentosa, enzyme activity was either at trace level or altogether absent. Acid alpha-D-mannosidase activity therefore appears to be the first biochemical feature common to both histiocytosis X and the Langerhans cells. The significance of the finding for the present theory of the histogenesis of the above tumors is discussed.

Biopsy↗
PubMed1977

Ultrastructure of Ewing's Tumour.

Tumour tissue surgically excised from 10 patients bearing Ewing's tumour of bones was examined electron microscopically and histoenzymologically. In all cases the tumour was composed of polygonal cells with cytoplasm poor in organelles but with conspicuous aggregates of glycogen particles. There were numerous intercellular connections of desmosomal type and a distinct cell membrane bound positivity for alkaline phosphatase activity. In two cases in which there was a negative reaction for alkaline phosphatase, the lack of enzyme activity might have been related to cytotoxic treatment carried out for several months immediately before excision of the tissue used for histoenzymological studies. The problem of histogenesis of Ewing's tumour remains unresolved although some of the present findings support a haemangiogenic origin of the tumour.

Adolescent↗
PubMed1977

[Subendocardial cyst of the myocardium].

A small cyst lined with columnar ciliated epithelium was found under the endocarcium of the posterior wall of the left heart ventricle in a male aged 65 years. According to literary data, such cysts most probably originate from aberrant cell material descending from the primitive gut.

Aged↗
PubMed1976

Ultrastructure of experimental xanthogranulomatous pyelonephritis.

The ultrastructure of xanthogranulomas developing during obstructive suppurative pyelonephritis was studied in rats with a permanent ligature of one ureter and an intravenous injection of E. coli suspension. The xanthogranulomas consisted of macrophages with numberous phagolysosomes containing rests of phagocytosed polymorphonuclear leucocytes and bacteria. Lipids identifiable as triglycerides were found in such cells particularly as isolated intracytoplasmic droplets and, less frequently, within the phagolysosomes. The source of isolated intracytoplasmic lipid droplets within the macrophages has remained obscure. Their origin in the macrophages by synthesis could not be excluded, similarly as in the polymorphonuclear leucocytes. PAS positive cells occurring as late as 2 months after the beginning of the experiment at the periphery of xanthogranulomas contained multiple intracytoplasmic vacuoles, most probably phagolysosomes. These cells, with high probability the oldes ones of the macrophagic population in the xanthogranulomas were virtually devoid of lipid droplets.

Animals↗
PubMed1976

Spermatic granulomas of ischemic origin in the rat epididymis.

The sequelae of the permanently reduced blood flow through the testes of rats, in which stenosis of the abdominal aorta had been produced by inserting an incomplete ligature between the two renal arteries, were studied. In a high proportion of animals, spermatic granulomas occurred unilaterally or bilaterally in the epididymides. Their development was proceded by an ischemic injury; the contents of the canaliculi penetrated into the interstitium, producing a marked macrophagic reaction, which developed after the 5th day. Simultaneously, ischemic lesions were observed in the testes.

Animals↗
PubMed1975

[Staining of Mycobacteria using non-traditional methods].

Nine modifications of the Gram method were tested with respect to their ability to stain mycobacteria. The results obtained were rather variable. Moreover it appeared that not all the methods would reliably visualize mycobacteria within histological sections. In particular, the mycobacteria occurring in a case of fibrocaseous tuberculosis appeared to be less stainable by the Gram method. If the Ziehl-Neelsen and the Gram method were combined to stain a single section, only some mycobacteria appeared to take the blue Gram stain.

Humans↗