Biomedical subjects
Publications and source records attributed to K Lapis.
4 epithelial thymomas out of 36 various types of it were studied electronmicroscopically. The following types were distinguished: clear cell thymoma, dark cell, solid thymoma, lacunar and spindle cell thymoma. These types of thymomas differ not only morphologically, but clinically. Authors suggest, that these tumours take their origin from the star-shaped clear- and dark medullar epithelial cells.
Epithelial cells of hyperplastic thymuses, removed because of myasthenia gravis were studied electronmicroscopically and morphometrically. The correlation between the age of patients and the number of epithelial cells of the thymus is discussed. Various type of epithelial cells are distinguished. Authors believe, that in the pathogenesis of myasthenia gravis beside the presence of lymphoid follicles in the hyperplastic thymus increase of the number of epithelial cells and their activation may take a part.
The mucosa of 17 gallbladders removed because of cholelithiasis was examined by means of transmission and scanning electron microscopy. Scanning electron micrographs revealed a mulberry-like organization of the normal human gallbladder mucosa. In acute inflammation, circumscribed ulcers were often seen; along their margins the epithelial cells were swollen and isolated from the surrounding cells. In chronic cholecystitis there was an extensive lack of epithelium on the irregularly oriented folds of the mucosa and the characteristic mulberry-like organization was preserved only in islets.
Paneth cells in the depth of Lieberkühn's crypts were studied ultrastructurally in three human jejunal biopsy material. Fine structural elements were observed indicative of phagocytosis. It is also assumed that the cells had regulatory function of normal intestinal flora. The importance of ultrastructural examinations of Lieberkühn's crypts under pathological conditions is emphasized.
Liver biopsy specimen of a patient with systemic lupus erythematosus was studied by light- and electron microscopy. On the background of the nonspecific hepatitis of a mild degree ultrastructural changes of the liver were revealed. Diffuse damage to the mitochondria and the vascular pole of the cells have been found. In the vascular endothelial cells of the liver presence of the so called tubuloreticular inclusions was observed. This can be regarded as the manifestation of the systematic disease in the liver.
Buccal mucosa of six patients with leukoplakia and normal controls was examined by scanning electron microscopy. Findings have shown that: 1. there is a difference between the surface epithelial cells of the normal mucosa and those of the mucosa with leukoplakia; 2. according to the various clinical forms of the leukoplakia there are differences between the epithelial cells: in leukoplakia verrucosa presence of keratinized epithelial cells, in leukoplakia erosiva absence of the cell-connecting structures seems to be a characteristic feature; 3. in leukoplakia erosiva with dysplasia atypical arrangement of the cytoplasmic processes of surface epithelial cells can be observed; 4. the most striking difference was revealed between the cells of the normal mucosa and those of leukoplakia erosiva.
Ultrastructural examination of 28 human pituitary adenomas was performed. Findings were correlated to the clinical history and light microscopic observations. As revealed by light and electron microscopy 15 adenomas were of the chromophobe type causing no endocrine dysfunction. In 8 cases acidophilic adenomas were associated with endocrine symptoms. In this group two adenomas were of the densely granulated type, whereas 6 of the sparsely granulated type. The latter showed marked ultrastructural signs of enhanced secretory activity. Five cases corresponding electronmicroscopically to sparsely granulated acidophilic adenomas but causing no endocrine symptoms constituted a separate group. They suggest the possibility of the production of abnormal proteins by this type of adenoma cells. Oncocyte cell-groups were seen in chromophobe adenomas. Morphometric data on granule size and distribution proved to be useful in the differentiation of chromophobe and acidophilic adenomas. Hypertrophic cell organelles, filamentous and tubular structures are interpreted as ultrastructural signs of cellular adaptation.
Fibroblast cultures were established from the lung tissue of CBA T6T6 mouse embryos. Lines characterized by infinite growth transformation (MFL) were used as untreated controls till the 21st and 29th passages, respectively. After that period, an unrestrained growth transformation developed spontaneously. The cell line was then designated as STMFL. At the 8th passage of an MFL, 20-methylcholanthrene (MC) treatment was performed. The treatment resulted in a cell line (MCMFL) characterized also by unrestrained growth transformation. The nuclear protein pattern obtained by two-dimensional gel electrophoresis showed differences between STFL and MCMFL. The activity of two microsomal enzymes - aryl hydrocarbon hydroxylase and ethylmorphin demethylase - measured in the exponential growth stage of the cultures showed a decrease in the case of STMFL, compared to the MFL, and practically disappeared in the case of MCMFL.
Explore the source record for details and available documents.
The changes developing in functioning saphenous vein transplants were studied by light and electron microscopy in three human cases. The degenerative signs appearing in the smooth muscle cells of the graft, as well as the glycogen accumulation and the changes of the cell organelles are discussed. Beside the thick elastic fibres visible under the light microscope in the graft functioning for 22 months the electron microscope revealed as a characteristic lesion the development of elastic fibres among the young collagenous fibres. It is emphasized that degenerated, sclerotic and varicose veins should not be used as grafts since no good results can be expected from them.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The liver protective effect of Aicaphosphate in CC1(4)-induced acute, as well as CC1(4)-and thioacetamide-induced subacute and chronic liver damages is demonstrated. The effect of the protective drugs was studied in the forms of pre-, simultaneous and delayed treatment in acute and chronic liver damages induced by various toxic agents. The degree of liver damage was determined by morphological and biochemical methods, complementary to each other. For the completion of histological studies and morphometry used for the determination of the degree of fibrosis biochemical investigations are performed. In acute liver damage the determination of DNA, protein and lipid contents of the liver tissue and the radioactive aminoacid incorporation rate should be carried out with a simultaneous analysis of the serum enzymes. In chronic liver damage, the measurement of the hydroxyproline and DNA contents of the liver give useful data for the determination of the severity of the lesion and the effect of the protective drugs, respectively.
Explore the source record for details and available documents.
Explore the source record for details and available documents.