Search PubMed⌕ Search

Biomedical subjects

A Sayal

Publications and source records attributed to A Sayal.

27 records · Page 2Linked to original sources
PubMed1993

The effects of selenium supplementation on antioxidative enzyme activities and plasma and erythrocyte selenium levels.

Plasma and erythrocyte selenium levels in rabbits supplemented with therapeutic doses of selenium were studied by Zeeman graphite furnace atomic absorption spectrometry using a new palladium-ascorbic acid chemical modifier in order to achieve a higher precision. An improved coupled test procedure was used to determine the glutathione peroxidase (GSH-Px) activities. Superoxide dismutase activities were measured employing a method for the clinical assay of the enzyme. The selenium levels and GSH-Px activities both in the plasma and erythrocytes were higher in the supplemented group when compared to the controls. The SOD activities were increased in the erythrocytes but remained unchanged in the plasma. Or the other hand, a higher copper/zinc ratio was found both in the plasma and erythrocytes of the supplemented group. These findings support the importance of the dietary selenium intake in terms of the principal role of selenium in the cellular antioxidative mechanisms and imply that measurements of plasma selenium levels may be a notable sensitive indicator of the short-term selenium status.

Animals↗
PubMed1992

Trace elements in hydatid disease.

The serum and cyst fluid levels of selenium, zinc and copper were investigated both in patients and sheep with hydatid cysts. Results were compared with those of healthy subjects in both species. The serum values of Se, Zn and Cu in healthy subjects were 60.24 +/- 1.96 micrograms/L, 0.59 +/- 0.07 mg/L, and 1.01 +/- 0.08 mg/L, respectively. The corresponding serum values of the three trace elements in patients with hydatidosis were 41.30 +/- 1.94 micrograms/L, 1.27 +/- 0.08 mg/L, and 0.89 +/- 0.09 mg/L. These results show a decrease in Se and Zn, and a rise in Cu in sera of patients with hydatid disease. Similar results were obtained in infested sheep as related to the healthy control animals. Our results on the three trace elements were found to correlate well with the incidence of cirrhosis, malignant and infectious diseases and arthritis. Se was not detectable in cyst fluid, while Cu and Zn levels were found significantly lower than serum levels. Cu and Zn levels in cyst fluid showed no difference in both species. Variations in serum Cu, Zn and Se levels were insignificant with regard to the genus of the host and the fertile capacity of the hydatid cyst.

Adult↗
PubMed1991

Selenium and Behçet's disease.

Behçet's disease is an inflammatory disorder of unknown etiology, characterized by recurrent oral and genital aphthous ulcers, ocular inflammation, and skin lesions of erythema nodosum and acneiform eruptions. Selenium (Se) affects all components of the immune system, i.e., the development and expression of nonspecific, humoral, and cell-mediated responses. In general, a deficiency in Se appears to result in immunosuppression, whereas supplementation with low doses of Se appears to result in augmentation and/or restoration of immunologic functions. In this study, the distribution of Se and IgG, IgM in serum were compared in samples from healthy adult control and Behçet's disease patients. The serum Se levels were measured by AA-30-40 Varian Spectra, and immunoglobulins were measured by immunodiffusion technique. The mean (SD) serum Se level of 54.24 +/- 8.06 ng/mL among Behçet's disease subjects was significantly different (P less than 0.01) from that in the control subjects (90.01 +/- 9.94 ng/mL). We also measured IgG and IgM as 10.01 +/- 2.74 mg/mL and 1.26 +/- 0.29 mg/mL, respectively for patients, and 15.08 +/- 4.73 mg/mL and 1.58 +/- 0.43 mg/mL for controls. The mean values of IgG and IgM for patients were significantly (P less than 0.05) different from the values of controls. It seems, therefore, that a deficiency in selenium impedes the humoral immune response.

Adult↗
PubMedDate not supplied

Serum selenium and glutathione-peroxidase activities and their interaction with toxic metals in dialysis and renal transplantation patients.

Selenium, aluminum, cadmium, and magnesium concentrations and glutathione-peroxidase activities in sera of 35 healthy individuals, 30 renal transplants, and 30 hemodialysis patients were measured. Serum selenium, aluminum, and cadmium concentrations in both groups of patients were higher than the controls (p less than 0.001), whereas the serum glutathione-peroxidase levels were lower (p less than 0.001). According to our results, it can be concluded that the patients receiving hemodialysis are subjected to more toxic elements than the transplantation patients. These findings imply that dietary selenium supplement may be suggested in renal failure for the detoxification of elements, such as cadmium and mercury. The essential trace element selenium takes part not only in the direct protection of endothelial cells against the accumulation of aggressive oxygen species, but also in the prevention of the toxic effects of cadmium or in the modulation of the active calcium transport.

Adolescent↗
PubMedDate not supplied

Plasma glutathione peroxidase activity and selenium levels of newborns with jaundice.

The plasma glutathione peroxidase (GSH-Px) and selenium (Se) levels were determined in 31 newborns affected by jaundice (NWJ). The GSH-Px levels of both full-term and premature newborns exhibiting jaundice and having a birthweight lower than 2000 g were significantly low (p < 0.05) when compared to controls. No significant differences were found in the corresponding Se levels, which were similar in all groups and independent of the pregnancy period and birthweight.

Glutathione Peroxidase↗
PubMedDate not supplied

Metabolic ratios of four probes of CYP2D6 in Turkish subjects: a cross-over study.

The relationships among the metabolic ratios for the standard probe drugs of CYP2D6 activity, such as debrisoquine, sparteine, metoprolol and dextromethorphan, were studied in 32 Turkish subjects. All subjects were randomly selected according to their phenotypes from a group of 111 Turkish subjects whose oxidation status had been tested for debrisoquine previously. All subjects were given a 10 mg debrisoquine tablet, a 100 mg sparteine tablet, a 100 mg. metoprolol tablet and a 20 mg dextromethorphan capsule orally with a wash-out period of at least 1 week between each probe administration. Metabolic ratios were calculated as percentage of dose excreted as parent drug/percentage of dose excreted as its hydroxymetabolite of parent drug in 0-8 h urine. Three poor metabolisers (PM) of debrisoquine were identified. They were also PMs of the other test probes and no misclassification by the 4 phenotyping methods was observed. All six correlations among the metabolic ratios of the 4 probe drugs assessed by Spearman's rank test were highly significant (P < 0.001). The present findings indicate that the oxidative metabolism of debrisoquine, sparteine, metoprolol and dextromethorphan is catalysed by the same cytochrome P450 in the Turkish subjects.

Adult↗
PubMedDate not supplied

Omission of the deconjugation step in urine analysis and the unaltered outcome of CYP2D6 phenotyping with dextromethorphan.

The present study was aimed at determining whether the deconjugation step in chemical analysis could be omitted without altering the outcome of phenotyping CYP2D6 with dextromethorphan. This drug and its metabolite, dextrorphan, were assayed by high-performance liquid chromatography (HPLC) in urine. Urinary levels of dextromethorphan and dextrorphan with and without enzymatic (beta-glucuronidase) treatment of urine and the metabolic ratios for dextromethorphan were determined in 45 subjects. Although the enzymatic treatment did not alter the urinary concentration of dextromethorphan in both phenotypes, it increased the urinary concentration of dextrorphan in both poor and extensive metabolizers by 3.7- and 12.8-fold, respectively. A urinary unconjugated dextromethorphan/unconjugated dextrorphan metabolic ratio of 2.00 and a total dextromethorphan/total dextrorphan metabolic ratio of 0.30, respectively, identified three poor metabolizers. Enzymatic treatment decreased the urinary antimode value. Moreover, the urinary metabolic ratio based on unconjugated dextrorphan and dextromethorphan correlated well with that based on assay of total dextrorphan and dextromethorphan (rs = 0.9458, P < 0.001). The results show that urinary analysis of dextrorphan and dextromethorphan omitting the enzymatic deconjugation step is a fast, reliable and sensitive method and could be used for studying CYP2D6 type genetic polymorphism in man.

Adolescent↗