PubMed Health⌕ Search

Biomedical subjects

V Holecek

Publications and source records attributed to V Holecek.

At least 19 recordsLinked to original sources
PubMed1996

[Free radial activity in patients with pneumoconioses].

The authors examined indicators of the effect of free radicals (MDA, SOD, GSHPx, selenium) in 20 patients with notified simple silicosis or miner's pneumoconiosis, in 11 patients with complicated silicosis or miner's pneumoconiosis and in 10 patients exposed to fibrogenic dust without an X-ray finding of pneumoconiosis. No statistically significant differences between individual groups were found. Subsequent investigations should be focused on subjects with incipient pneumoconiosis who are not yet entitled to damages.

Aged↗
PubMed1996

[Free radicals in the central nervous system].

Central nervous system has a low antioxidative capacity, which is formed mainly by ascorbic acid. Therefore the cerebral tissue is threatened by the increased formation of free radicals and their metabolites (ROS--reactive oxygen species). ROS are formed such as in reperfusion phase after ischemia and in catecholamine metabolism, in oxidative stress due to hyperglycaemia. Polyunsaturated fatty acids (PUFA) are peroxidased by ROS; proteins and DNK are damaged as well. Free radicals are involved in etiology and pathogenesis of many CNS diseases, such as neuritis, Alzheimer disease, Parkinson disease, Huntington disease, aging and atherosclerosis of the brain, epilepsy, etc. During the antioxidant therapy it is necessary to consider the types of ROS, their origin and their mode of action, whether to administer hydrophilic or lipophilic antioxidants, eventually chelate agents, etc. Hydrophylic antioxidants are acting very soon after the administration, whereas the lipophilic ones reach their target tissues with a great delay. Therefore it is better to apply them preferentially like a prevention, if possible. Enzymatic antioxidants (SOD, GSPHx and catalase and others) are usually acting only for a short time. The methods of estimation of free radicals attacks are discussed as well their possible pathophysiological effects.

Animals↗
PubMed1996

[Free oxygen radicals and rheumatic diseases].

The authors assessed in blood some indicators of the reaction of the organism to the formation and action of free radicals in patients with rheumatoid arthritis, with other inflammatory articular diseases selected at random and with degenerative diseases of the joints and spine. From the results ensues that subjects with inflammations of the synovial membrane respond relatively frequently by a rise of indicators of the antioxidant system such as the activity of superoxide dismutase, glutathione peroxidase or the antioxidant capacity of plasma. Obviously a defence reaction of the organism is involved to the increased formation and action of free oxygen radicals in the inflamed articular lining. The authors conclude that the mentioned laboratory indicators of the action of free radicals could be used when checking the progress of treatment in rheumatic diseases.

Antioxidants↗
PubMed1995

[Administration of multivitamin combinations and trace elements in diabetes].

BACKGROUND: Many free radicals are formed in diabetes mellitus due to the oxidative stress in hyperglykemia. The objective of the investigation was to evaluate the influence of an antioxidant mixture and trace elements on some biochemical parameters in controls and diabetic patients. METHODS AND RESULTS: 13 controls (6 men and 7 women, the average age was 53 years) and 9 diabetic patients (4 men and 5 women, the average age was 52 years) were supplemented with multivitamin mixture and trace elements with respect to antioxidant activities. Both groups received the same amount of the mixture, controls 50 days, diabetic patients 35 days. Blood samples were measured before and after the treatment. Renal, liver tests and acid-base balance were not influenced. Apolipoprotein A increased significantly (p < 0.05). Glycosylated hemoglobin in the diabetic group decreased significantly from 9.4 +/- 1.6 to 7.2 +/- 1.5 mumol fructose/g of hemoglobin (p < 0.01). In the diabetic group increased the levels of ionorganic phosphorus from 0.99 +/- 0.08 to 1.15 +/- 0.13 mmol/L (p < 0.01), zinc from 10.4 +/- 1.3 to 14.3 +/- 1.7 mumol/L (p < 0.01), copper from 20.3 +/- 2.3 to 25.9 +/- 6.3 mumol/L (p < 0.05) and selenium in blood from 0.96 +/- 0.21 to 1.65 +/- 0.38 mumol/L (p < 0.001). Selenium in blood of the control group increased from 0.88 +/- 0.26 to 1.66 +/- 0.34 mumol/L (p < 0.001). The activity of superoxide dismutase (SOD) in diabetic group increased from 598 +/- 105 to 696 +/- 103 U/g of hemoglobin (p < 0.01), the activity of glutathion peroxidase (GSHPx) did not change, malondialdehyde (MDA) decreased from 7.1 +/- 1.1 to 5.8 +/- 1.1 mumol/L (p < 0.01) and uric acid decreased from 261 +/- 83 to 236 +/- 96 mumol/L (p < 0.01). CONCLUSIONS: Multivitamin mixture with trace elements significantly protects diabetic patients and the control group against injurous actions of free radicals. That is confirmed by the decrease of plasmatic malondialdehyde and uric acid and by the increase of superoxide dismutase in erythrocytes. The decrease of glycosylated hemoglobin reduces the probability of diabetic complications, the increase of plasmatic Zn and Se in the diabetic group increased the plasmatic antioxidant ability.

Diabetes Mellitus↗
PubMed1995

[Lipid peroxidation and the antioxidant system in bicarbonate hemodialysis and acetate-free biofiltration].

Acetate-free biofiltration (AFB) is a modern haemodiafiltration method used at present as a variant in treatment of chronic renal failure. In AFB and standard bicarbonate haemodialysis (BHD), performed under equal conditions in 20 patients with chronic renal failure the authors investigated the degree of lipid peroxidation and the antioxidant defence system. As a marker of lipid peroxidation they used malondialdehyde (MDA); as to antioxidant factors they investigated the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSHP) in red blood cells and the selenium (Se) concentration in blood. The MDA values were elevated in both dialyzation methods, as compared with 30 healthy controls (p < 0.001). The SOD value before AFB did not differ from controls, before BHD it was higher than in controls (p < 0.01). In the course of AFB or BHD the SOD values did not change. The GSHPx activity at the end of AFB rose significantly as compared with the initial value (p < 0.05) and the value during the 30th minute of AFB (p < 0.02). In BHD the GSHPx activity was lower than in controls and did not change during the procedure (p < 0.01). The selenium blood levels were before both AFB and comparative BHD lower than in controls (p < 0.001). The authors found a positive correlation between the GSHPx activity and the Se level. The rise of GSHPx activity at the end of AFB may imply improved antioxidant defence during AFB and contribute to reduced tissue damage by free radicals.

Adult↗
PubMed1992

[New findings on the clinical significance of magnesium].

Recent findings are concerned with the diagnosis, incidence, and therapy of hypomagnesaemia. The authors discuss the importance of Mg in stress, cardiac diseases, bone metabolism, neoplasms, blood clotting, in physical exertion and the Mg content of the diet.

Animals↗
PubMed1983

Conjugations of acrylonitrile and glycidonitrile with glutathione--a contribution to problems of metabolism of acrylonitrile.

The study of the conjugation of acrylonitrile and glycidonitrile with glutathione has demonstrated the capacity of glutathione of eliminating both acrylonitrile (manifesting mostly cyanide effects) and the primary product of its oxidative turnover, glycidonitrile (mutagenic effect), from acting toxicly. It appears, at the same time, however, that massive doses of acrylonitrile may endanger the biological system by depletion of large quantities of glutathione a schematic chart of the metabolic exchanges of acrylonitrile was suggested demonstrating that a part of the total amount of the excreted thiocyanate in the urine might also be accounted for by the cyanide having been produced by the enzymatically catalyzed conjugation of glycidonitrile with glutathione, with the ensuing secondary breakdown of the intermediary product cyanohydrin.

Acrylonitrile↗
PubMed1980

Two routes of acrylonitrile metabolism.

Acrylonitrile (AN) is metabolized in two different routes. The minor route of AN metabolism is its conversion to cyanide. In vitro experiments confirmed that this biotransformation proceeds via glycidonitrile (catalyzed by hepatic monooxygenases) and glycolaldehyde cyanohydrin (catalyzed by epoxide hydrase). Cyanohydrin is spontaneously decomposed to cyanide, which is then metabolized in vivo to thiocyanate by rhodanese. A major route of AN-metabolism (more than 2/3), however, proceeds via its conjugation with glutathione catalyzed by glutathione S-alkenetransferases, to N-acetyl-S-(2-cyanoethyl)cysteine as a final product.

Acrylonitrile↗