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Biomedical subjects

G Vajta

Publications and source records attributed to G Vajta.

52 records · Page 3Linked to original sources
PubMed1986

Morphological investigations on co-cultures of rat hepatocytes and the neonatal liver cell line RL 19.

Hepatocytes isolated from mature rats were cultivated together with proliferating liver cells derived from newborn rats (RL 19 line). The hepatocytes of the co-cultures were viable for long period and preserved their glucose-6-phosphatase activity and glycogen content longer than the mature rat hepatocytes cultured alone. Electron microscopy revealed that the RL 19 cells were covering the hepatocytes and growing beneath them. Both the RL 19 cells and the adult hepatocytes established tight contact with each other, but between the two cell types there was always a gap bridged by microvilli and resembling Disse's space. It is assumed that the envelope formed by the RL 19 cells may have a role in the maintenance of the differentiated hepatocyte structure.

Age Factors↗
PubMed1986

Experimental studies on the effect of hepatoprotective compounds.

The hepatopharmacological actions of Prostacyclin, 1-phosphate-4-amino 5-carboxamido-imidazole (AICA-P), Catergen, Silymarin and a thiazolidine compound were investigated by applications in in vitro and in vivo model systems. The usefulness of the in vitro system to screen for potential hepatoprotective agents and to investigate the molecular mechanism of these substances is shown. It was concluded that different patterns of hepatoprotective action were elaborated by the same drug depending on the model system used for testing. PGI2 and the thiazolidine compound showed remarkable protection in acute liver damage. However PGI2 circumvented only the CCl4 induced cellular injury, and was inactive in the galactosamine model system. The induction of cirrhosis could be modified by the simultaneous treatment with PGI2 or by the thiazolidine compound but the fully developed cirrhosis was not affected. On the contrary AICA-P and Silymarin treatment resulted in reduction of the amount of collagen in cirrhotic liver.

Aminoimidazole Carboxamide↗
PubMed1984

Effect of PGI2 in carbon tetrachloride-induced liver injury.

The hepatoprotective effect of prostacycline was studied after in vitro and in vivo CCl4 liver injury. It was found that PGI2 could partly restore the amino acid incorporation after in vitro CCl4 poisoning. In the in vivo system PGI2 was capable of decreasing the elevated SGOT levels and the accumulated triglyceride in the liver, and to increase hepatic glycogen content 24 hours after CCl4 injury.

Alanine Transaminase↗
PubMed1984

Polarization colours of collagen fibres: a sign of collagen production activity in fibrotic processes.

The maturation process of collagen fibres was investigated by the picro-sirius red/polarization light technique in experimental wound healing, in allyl-alcohol induced subacute and chronic liver fibrosis and in human biopsy material. Evidence was obtained that collagen fibres undergo a rapid maturation in fibrotic processes; the intensity of their birefringence increases and, at the same time, their polarization colour changes. Newly formed collagen fibres appear on the 4-6 mum thick sections in green polarization colour. Later, in a more mature stage, they became yellow, orange or red under crossed polaroids. The findings suggest that the simple picro-sirius red/polarizing light technique may be useful to form an opinion about the activity of the fibrotic process.

Animals↗
PubMed1983

Asbestos bodies in a bile duct cancer after occupational exposure.

A case of asbestosis after 5 years of occupational asbestos exposure is presented. At the postmortem examination, cholelithiasis and a cancer developing from the cystic duct were found and identified histologically as a squamous cell carcinoma. After digesting the tumor tissue, short asbestos bodies and fragments could be identified having a similar shape as those observed in the lung. The possible role of asbestos in the carcinogenesis of the observed bile duct cancer is proposed. The digestive examination of all malignant tumors of any origin after an asbestos exposure is suggested for the identification of the possible presence of ingested asbestos fibers, and to obtain further comprehensive human pathological data.

Adult↗
PubMed1982

Light, fluorescence and electron microscopic observations on vitamin A storing cells in allyl-alcohol induced liver damage.

Earlier studies have described vitamin A accumulation in perisinusoidal Ito cells, but not in portal fibroblasts. The aim of our experiments was to examine whether vitamin A pretreatment is really suitable for the distinction of the two cell groups, and to find out how these cells respond to the periportal injury caused by allyl-alcohol. Using very high doses of vitamin A we demonstrated that the portal fibroblasts, similarly to Ito cells, are able to store vitamin A, therefore in chronic liver injuries, when the lobular and sinusoidal structure is damaged, no difference can be seen between the two groups of cells (using the method suggested by the literature, so far). Our results suggest that both Ito cells and the fibroblasts in the portal region play an important role in the fibrogenesis following allyl-alcohol induced liver injury.

Animals↗
PubMedDate not supplied

The open pulled straw vitrification of ovine GV-oocytes: positive effect of rapid cooling or rapid thawing or both?

Three protocols for the open pulled straw (OPS) vitrification of ovine GV-oocytes with slow cooling-rapid thawing, rapid cooling-slow thawing, and rapid cooling-rapid thawing were tested. The effect of ultra-rapid cooling in liquid nitrogen slush and superfine open pulled straws (SOPS) was also studied. Our results prove that both rapid cooling and rapid thawing are contributing in improved results achieved with the OPS technology. The use of liquid nitrogen slush is beneficial for ovine GV stage oocyte nitrification.

Animals↗