Biomedical subjects
Publications and source records attributed to K Lapis.
Further comparative studies on the biological and biochemical features of virus-derived transplantable and chemically induced hepatomas may contribute to the knowledge of human hepatomas. Evidence for the reprogramming of gene expression found in chemically induced transplantable hepatomas [22] was also found in this virus-derived hepatoma.
Twelve to fourteen days after intravenous inoculation of MC29 virus (1 x 10(5)LD50) into 1-day-old turkeys, liver tumour developed in 100% of the infected animals and led to death of birds. The tumour proved to be hepatomas histologically and electron microscopically. Numerous C-type particles were detectable among the tumour cells, as well as budding from the cell membrane. C-type particles were also observed in the tumour-free liver tissue in the spaces between the cells, budding was not detectable. Large number of virus particles were found in spleen extracellularly and intracellular vacuoles. Kidney tumours did not develop, but a few extracellular virus particles were located in the tissue. The MC29 virus-induced primary liver tumour in the turkey seems to be a suitable model for the morphological study of the relationship between oncogenic viruses and eukaryotic cells.
Light, transmission, and scanning electron microscopic studies were performed on 24 gallbladders with thin walls, without inflammation, extirpated by cholecystectomy because of gallstones and on five, free from biliary diseases, obtained by autopsies. Examination of gallbladders and epithelium covering the valvula spiralis (Heister) of the ductus cysticus showed the surface structure of the epithelium covering the Heister valve to be mulberry-like and characteristically pleated, similar to the epithelial lining of the gallbladder. In cases of cholelithiasis, several denuded areas were detectable on the valves. The epithelial lining of the gallbladder was intact. As a new observation, we describe the appearance of worm-like processes on the lateral surface of detached epithelial cells, seen during the course of scanning electron microscopic study. These probably correspond to interdigitating cell junctions observed by transmission electron microscopy.
Ultrastructural changes in 35 neuromuscular junctions taken from myasthenic patients (in 2 cases: hyperplasia of the thymus, in 1 case: epithelial thymoma was present) treated with anticholinesterase during 1--2 years, appeared to be similar to those observed in non-myasthenic patients with lymphoid thymoma (getting no treatment with anticholinesterase). Number of the secretory granules in the epithelial cells of the thymus was in accordance with the severity of the disease. It can be assumed, that in the disturbance of the neuro-muscular transmission of the stimuli the activation of the epithelial cells may play a part.
Morphological findings in Niemann-Pick disease of an infant are described. By electron microscopy in the cytoplasma of leukocytes and hepatocytes mostly moderaty electrodense unmature lipid-containing cytosomes were seen. Morphological alterations found in the leukocytes and hepatocytes in contrast to the earlier findings appeared to be similar. Authors stress the importance of electron microscopic investigation of peripheric leukocytes.
Six human uterine tube were studied by scanning-and transmission electron microscopy. Ciliated epithelium and epithelium covered by microvilli could be identified by both method. In the area of the fimbriae the majority of cells appeared to be ciliated epithelium, but near to the uterus their number decreased. At every part of the uterine tube cells of the ciliated epithelium were situated deeper than cells covered by microvilli. In the age group studied (20-45 year) no age-dependent differences in the structure of the mucosa or in the number of the different cells could be revealed.
Authors studied ultrathin cestions of lung of ten newborns died of IRDS in the various stage of the disease. It was established that lamellar bodies are already formed in the initial phase of the disease. In the first two clinical phases by pneumocytes type II structure of the intracytoplasmic and intaraalveolar lamellar bodies differs from the normal, and they can not form air-cell interphase. In the third clinical phase--in the phase of the resolution-mature lamellar bodies of normal structure are formed and get into the alveolar space, thus the condition of formation of air-cell interphase is given.
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Cultures of CBA T6T6 mouse embryo cells were transformed by 20-methylcholanthrene (MC) treatment in vitro. Untreated and MC treated cells and reexplanted cells of tumours originating from MC treated cells were compared by scanning electron microscopy (SEM). The 3 cultures showed considerable differences in the situation of the cells compared to each other, as well as in the number and shape of the surface formations.