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T Farkas

Publications and source records attributed to T Farkas.

At least 91 records · Page 5Linked to original sources
PubMed1987

Inositol phospholipid turnover and protein kinase C translocation are stimulated by poly(I).poly(C) in human amnion cells (UAC).

Polyinosinic-polycytidylic acid, a potent inducer of inducer of interferon (IFN) production and activator of some IFN-induced enzymes, inhibits [3H]uridine incorporation into the RNA of vesicular stomatitis virus even in the absence of IFN synthesis, transiently triggers the breakdown of inositol phospholipids and activates the translocation of protein kinase C. Since IFNs also have similar activities these results suggest that IFN induction and IFN function are realised through common biochemical pathways.

Amnion↗
PubMed1987

Early vascular changes in rabbit subchondral bone after repetitive impulsive loading.

The sequence of vascular and bony changes that precedes experimental osteoarthrosis was observed in rabbits. The subchondral bone underlying the weight-bearing portion of the medial tibial condyle and the talocalcaneal joint were examined after two, three, and six weeks of 50-ms and 500-ms repetitive loading at 1 Hz for 40 minutes each day. Vascular alterations were evident in the subchondral bone of the talocalcaneal joint after three weeks of a 50-ms load regime. A 10% increase in bone mass and a significant increase in the number of small diameter vessels were observed after six weeks. No changes were observed in the tibial subchondral bone, consistent with the measured attenuation of load distal to this joint. No changes were observed in either tibial or calcaneal subchondral bone in the 500-ms load group. Impulsive loading promotes early vascular changes in subchondral bone, which are developed in response to both the magnitude and the rate of loading.

Animals↗
PubMed1986

Microsomal desaturation of stearic acid in relation to lymphocyte activation.

The conversion of stearic acid to oleic acid (delta 9-desaturase) was followed in mouse thymocytes stimulated by either concanavalin A or concanavalin A + interleukin-2 resulting in different rates of cell proliferation. To estimate the plasma membrane turnover of oleic acid as compared to that of a saturated fatty acid, double-label experiments ([14C]oleic acid, [3H]palmitic acid) were performed. Following an inhibition delta 9-desaturase was found to be activated from the fourth hour of stimulation. In the early period of cell activation this process proved to be independent of protein synthesis, whereas in the stage of proliferation it was dependent on it. Increased membrane fluidity in the first 30 min of activation is not likely due to enrichment of oleic acid. Cell proliferation and microsomal desaturation seem to be coupled and an increasing amount of oleic acid is at least one of the factors resulting in increased fluidity of the surface membrane of proliferating cells.

Animals↗
PubMed1985

Lipid content and ESR determination of plasma membrane order parameter in Candida albicans sterol mutants.

Sterol intermediates of ergosterol biosynthesis in seven sterol mutants of Candida albicans were determined by gas-liquid chromatography. Only one of them could synthetize ergosterol, while in the others sterol biosynthesis was blocked beyond zymosterol. Alterations in sterol composition were correlated with a slight increase in saturation and a decrease in the chain length of fatty acids, and increases in phosphatidylinositol and phosphatidic acid, and decreases in phosphatidylcholine and phosphatidylserine contents. During exponential growth, as measured on their protoplasts using the intercalated fatty acid spin probe, 5-doxylstearic acid, these single mutants exhibited higher plasma membrane order parameters than their ergosterol-producing parental strain, designated 33 erg+, as follows: erg-12 greater than erg-16 greater than erg-37 much greater than erg-2 greater than erg-20 greater than erg-40 greater than erg-41 greater than 33 erg+. The mutants displayed significantly higher phase-transition temperatures, measured in a reconstituted lipid-water dispersion, than their parental strain.

Candida albicans↗
PubMed1984

Regional brain glucose metabolism in chronic schizophrenia. A positron emission transaxial tomographic study.

Thirteen diagnosed schizophrenics and 11 normal controls were studied with a method using the PETT III positron emission tomograph (PET) and fluorodeoxyglucose labeled with fluorine 18. Each subject also had a computed tomographic (CT) scan. For each subject, two brain levels, one through the basal ganglia and one through the semioval center, were analyzed for the mean regional metabolic glucose rate. Specifically, relationships between frontal and posterior regions were evaluated. The CT scans of matching levels were superimposed on the functional PET images to provide anatomic criteria for region of interest selection. While no whole-slice metabolic differences were apparent between groups, schizophrenics had significantly lower activity in the frontal lobes, relative to posterior regions. The medicated and drug-free groups did not differ from one another in these regards. Trait v state dependency of the phenomenon was analyzed, and several technological limitations were considered.

Adult↗
PubMed1984

Adaptation of fatty acid composition to temperature--a study on carp (Cyprinus carpio L.) liver slices.

Liver slices obtained from warm-, and cold-adapted carp were incubated in the presence of [1-14C]sodium acetate, -stearate, -linoleate, and -linolenate at various temperatures and the distribution of radioactivity among different phospholipid fatty acids was determined. Relative labelling of saturated fatty acids is reduced, while that of long chain polyunsaturated fatty acids, especially of docosahexanoate, is increased with decreasing temperatures. Liver slices of cold adapted carp produced a fatty acid population at 25 degrees C indistinguishable from that produced by warm adapted ones at the same temperature. Liver slices obtained from cold-, and warm-adapted animals start to reorganise the pattern of labelling immediately after the exposure to the opposite temperatures as evident from pulse-chase labelling experiments. Desaturation of saturated and various unsaturated fatty acids is initiated immediately after down-shift of the temperature. This cold induced increase in desaturase activity is prevented by cycloheximide in the incubation medium. It is concluded that phospholipid fatty acid composition is continuously adjusted to the temperature and is governed partly by temperature coefficient of fatty acid synthetase and partly by induction or deactivation of desaturases in cold and warm, respectively.

Acclimatization↗
PubMed1984

Changes in the cartilage proteoglycans in relation to age and osteoarthrosis.

Changes in the extracellular components of various connective tissues with time and continuous use, as well as within experimentally-induced and human pathological conditions, were studied by morphological, chemical and biochemical methods. Osteoarthrotic lesions were produced surgically by implantation of polyethylene sheets, by continuous compression of the knee joint, and by intraarticular papain injection. Results of the model experiments showed that, irrespective of the method used for the production of experimental cartilage lesions, the alterations are strikingly similar. Within connective tissues a gradual deterioration takes place, as measured by marked differences in the histological and histochemical patterns. The degradative changes occur primarily in the matrix, resulting in a significant decrease in proteoglycan content. Under conditions of stress, in young animals, chondrocytes seem to revert to the chondroblastic state, showing mitotic figures, and are capable of producing matrix much more rapidly than is normally seen. This increased activity might be regarded as a nonspecific "feed-back" response of cells, leading to a reparative normalization of the various destructive tissue alterations.

Aging↗
PubMed1980

The action of non-ionic detergents on the extraction of phospholipids and proteins from rat liver and rabbit heart membranes.

Triton X-100 and Lubrol PX at similar concentrations extracted more phospholipid than protein from rat liver and rabbit heart membranes, as compared with their original protein and phospholipid contents, respectively. All the types of membrane phospholipid were solubilized from rat liver membrane with the used non ionic detergents, but less sphingomyelin was extracted than phosphatidylcholine and phosphatidylethanolamine.

Animals↗
PubMed1979

Development of carcinoma of the breast at the site of an implanted pacemaker in two patients.

We report here on two female patients who had permanent pacemakers implanted in their chests and who developed carcinoma of the breast subsequently. An association is suspected between the breast cancer and the pacemaker, which is implanted in an area which borders with the mammary gland or is even right within it. This suspicion led us lately to change in female patients the site of the subcutaneous pocket for the implantation of the pacemaker to a position higher in the chest than before. Moreover, we advocate frequent breast examinations in all female patients with implanted pacemakers.

Adenocarcinoma↗