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Biomedical subjects

S Fekete

Publications and source records attributed to S Fekete.

At least 91 records · Page 5Linked to original sources
PubMed1985

Purification and characterization of the 2-methyl branched-chain Acyl-CoA dehydrogenase, an enzyme involved in NADH-dependent enoyl-CoA reduction in anaerobic mitochondria of the nematode, Ascaris suum.

The 2-methyl branched-chain acyl-CoA dehydrogenase was purified to homogeneity from mitochondria of the parasitic nematode, Ascaris suum. The native molecular weight of the enzyme was estimated to be 170,000 by gel filtration. The enzyme migrated as a single protein band with Mr = 42,500 during sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggesting that the enzyme is a tetramer composed of identical subunits. The enzyme exhibited absorbance maxima at 272, 375, and 452 with a ratio 7.9:0.8:1.0, respectively. FAD content was estimated to be 0.9 mol/mol of subunit and the absorption coefficient of FAD at 452 nm was 14.1 mM-1 cm-1. The purified enzyme dehydrogenated both 2-methylbutyryl-CoA and 2-methylvaleryl-CoA with apparent Km and Vmax values of 18 microM and 1.62 mumol/min/mg and 21 microM and 1.58 mumol/min/mg, respectively. This enzyme also appeared to dehydrogenate butyryl-CoA, valeryl-CoA, and octanoyl-CoA but at a much lower rate. The enzyme did not dehydrogenate propionyl-CoA, isobutyryl-CoA, isovaleryl-CoA, and palmitoyl-CoA. Tiglyl-CoA and 2-methyl-2-pentenoyl-CoA were identified as reaction products from 2-methylbutyryl- and 2-methylvaleryl-CoA, respectively. Dehydrogenating activity with both substrates was inhibited by tiglyl-CoA, acetoacetyl-CoA, and straight chain acyl CoAs of increasing chain length. N-Ethylmaleimide and p-hydroxymercuribenzoate had little effect on dehydrogenating activity but the heavy metals Hg2+ and Ag2+ were potent inhibitors. Physiologically, the dehydrogenase functions as a branched-chain enoyl-CoA reductase. Incubations of A. suum submitochondrial particles, NADH, tiglyl-CoA, purified A. suum electron-transfer flavoprotein, and the 2-methyl branched-chain acyl-CoA dehydrogenase resulted in the rotenone-sensitive, dehydrogenase-dependent formation of 2-methylbutyryl-CoA.

Acyl-CoA Dehydrogenases↗
PubMed1985

Meningitis caused by Gordona aurantiaca (Rhodococcus aurantiacus).

In a case of hairy cell leukemia, Gordona aurantiaca (Rhodococcus aurantiacus) was isolated from cerebrospinal fluid as the pathogen responsible for lethal infection of the central nervous system. The pathogen had been isolated previously from one case of pulmonary infection process only.

Actinomycetales Infections↗
PubMed1985

Thyroxine, triiodothyronine, reverse-triiodothyronine, and other physiological characteristics of periparturient cows fed restricted energy.

Eighty-six cows were assigned to two equal groups with group A fed according to National Research Council recommendations for total digestible nutrients for the 8 wk before parturition and group B was fed 21% higher energy in the first 6 wk and 15% higher in the last 2 preparturient wk. Thyroxine in blood serum decreased in both groups 14 days before and on the day of delivery. It was significantly lower in group A. Findings were similar with triiodothyronine. Blood serum concentrations of reverse-triiodothyronine of group A was significantly higher in group A on day 28 and 14 than group B before delivery. Energy intake had little influence on the serum concentrations of other constituents (albumin, total protein, immunoglobulin G, total and free cholesterol, nonesterified fatty acids). Restricted energy intake that does not alter thyrotropin-thyrotropin-releasing hormone secretion results in higher rate of production of reverse-triiodothyronine and in decreased serum concentration of triiodothyronine. Slight changes of energy balance might be indicated readily by reverse-triiodothyronine concentration in blood serum.

Animal Nutritional Physiological Phenomena↗
PubMed1984

2-Methylbutyryl CoA dehydrogenase from mitochondria of Ascaris suum and its relationship to NADH-dependent 2-methylcrotonyl CoA reduction.

Acyl CoA dehydrogenase and electron-transfer flavoprotein have been isolated and partially purified from mitochondria of the anaerobic nematode, Ascaris suum. Dehydrogenase activity was greatest with 2-methylbutyryl CoA and the relative substrate specificities of the ascarid dehydrogenase(s) differ greatly from their mammalian counterparts. It appears that the ascarid dehydrogenase functions physiologically as a reductase, catalyzing the final step in the synthesis of branched-chain fatty acids. In fact, incubations of A. suum mitochondrial membranes with electron-transfer flavoprotein, 2-methylbutyryl CoA dehydrogenase, 2-methylcrotonyl CoA and NADH resulted in a substantial, rotenone-sensitive, 2-methylbutyrate synthesis. These results suggest that the ascarid electron-transport chain and at least two soluble mitochondrial proteins are involved in the NADH-dependent reduction of 2-methylcrotonyl CoA.

Acyl Coenzyme A↗
PubMed1980

Serum proteins in processes associated with an increase in the monoclonal and polyclonal immunoglobulin levels.

The sera of patients with IgG-myeloma, IgM-macroglobulinaemia and with processes accompanied by high polyclonal Ig-levels were measured by radial immunodiffusion for immunoglobulins, coeruloplasmin, alpha-2-macroglobulin, C3-component, transferrin, alpha-1-antitrypsin, alpha-2-haptoglobin and haemopexin. In the presence of typical changes in the immunoglobulin concentrations, elevation of alpha-2-macroglobulin was found only if polyclonal Ig was increased. The concentration of the C3 component was reduced only in IgM macroglobulinaemia, that of transferrin only in IgG-myeloma, that of alpha-2-haptoglobin only in IgM-macroglobulinaemia and in case of increased polyclonal Ig.

Adult↗
PubMed1976

Comparative observations in the treatment of acute leukaemia.

The results of treatment of 84 acute leukaemia patients during a 15-year period are reported. Sixty-three of the patients suffered from acute myeloid leukaemia, 14 had blastic crisis of chronic leukaemia and 7 had acute myelomonocytic leukaemia. Administration of prednisolone + purinethol, prednisolone + vincristine, and prednisolone + vincristine + purinethol combinations resulted in partial remission. The best results were achieved with the combination ARA-C + thioguanine + prednisolone, which produced complete remission in 2 out of 8 cases. One patient was refractory to this treatment.

Adolescent↗
PubMed1975

Effect of alphamethyldopa and of phenobarbitone on angiotensin responsiveness and renin activity in man.

Changes of angiotensin sensitivity and renin activity were studied in 25 subjects after one week's administration of alphamethyldopa, phenobarbitone and both compounds. The increase of angiotensin sensitivity produced by alphamethyldopa is abolished by the simultaneous administration of phenobarbitone, moreover angiotensin sensitivity rather decreases. Peripheral renin activity does not change in either of the cases. Phenobarbitone per se does not affect either angiotensin sensitivity or plasma renin activity. Possible mechanisms of the phenomenon are outlined. It is also concluded that angiotensin sensitivity may change considerably without detectable alteration of plasma renin sensitivity.

Adolescent↗