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Biomedical subjects

E B Thorling

Publications and source records attributed to E B Thorling.

At least 19 recordsLinked to original sources
PubMed1992

Glutathione redox cycle enzymes and selenium in severe rheumatoid arthritis: lack of antioxidative response to selenium supplementation in polymorphonuclear leucocytes.

The antioxidant capacity of the glutathione redox cycle and the concentrations of selenium in serum, red blood cells or whole blood, and polymorphonuclear leucocytes was evaluated in nine patients with severe rheumatoid arthritis (RA) and eight healthy controls receiving daily supplementation with 250 micrograms selenomethionine for six months. Serum and whole blood concentrations of selenium and the activity of the selenium dependent enzyme glutathione peroxidase (GSH-Px) were low in the serum, red blood cells, and polymorphonuclear leucocytes of patients with RA before selenium supplementation. During supplementation serum and whole blood concentrations of selenium and the activity of GSH-Px in serum and red blood cells of patients with RA and serum GSH-Px in controls increased. Selenium and GSH-Px in polymorphonuclear leucocytes were unaffected in patients with RA in contrast with the controls where both were augmented. Glutathione reductase activity in the red blood cells and polymorphonuclear leucocytes of patients with RA was low but increased during selenium supplementation. Whole blood concentrations of glutathione were slightly lower in patients with RA than controls and no difference in the content in polymorphonuclear leucocytes was found between the groups. The activity in red blood cells of glucose-6-phosphate dehydrogenase was high in patients with RA, indicating sufficient function of the hexose monophosphate pathway. The reduced antioxidant activity of the glutathione redox cycle in patients with severe RA was mainly due to the low availability of selenium. This was further supported by the response to selenium supplementation in serum and red blood cells. In the polymorphonuclear leucocytes, however, no biochemical effects of selenium supplementation were seen. This lack of antioxidative response could play a pathogenetic part in inflammation in patients with RA.

Adult↗
PubMed1991

Selenium in human mammary carcinogenesis: a case-cohort study.

In a prospective study conducted on the island of Guernsey a cohort of 5162 ostensibly healthy women was enrolled between 1967 and 1976. Blood samples were drawn from each participant, who also completed a questionnaire, which provided information on established risk indicators in human mammary carcinogenesis. Plasma selenium levels were measured in 46 breast cancer cases diagnosed a mean of 11 (S.D. 4) years after entry into the study cohort and in an age-stratified sample of 138 women drawn from the study base. Plasma selenium level in the cases was 109 (28) micrograms/l and in the base sample 103 (22) micrograms/l (95% confidence interval for the overall difference, -2 to 14 micrograms/l). The adjusted relative risk of developing breast cancer in the different quartiles of the selenium distribution was 0.80, 0.79, 0.72 and 1.00, respectively. Thus, in the present study selenium was not a strong indicator of human breast cancer risk.

Adult↗
PubMed1991

Selenium in human mammary carcinogenesis: a case-referent study.

In a case-referent study on the possible role of selenium in human mammary carcinogenesis, serum selenium was found to be 79 +/- 12 micrograms/l in 66 cases and 81 +/- 12 micrograms/l in 93 referents. An internal trend in serum selenium was observed among cases (TNM stage I 81 +/- 11 micrograms/l and TNM stage II 76 +/- 13 micrograms selenium/l), indicating disease-mediated changes. The evaluation of selenium as a risk indicator in human breast cancer was therefore restricted to TNM stage I patients (n = 36). Multiple logistic regression analyses including variables associated with selenium levels revealed no association between selenium levels and breast cancer risk.

Adenocarcinoma↗
PubMed1991

Glutathione peroxidase in early and advanced Parkinson's disease.

A defective antioxidant scavenging system plays a major role in one of the theories of the pathogenesis of Parkinson's disease. The aim of this study was to investigate whether there is a general difference in antioxidant activity between early and advanced cases of Parkinson's disease. Twenty five recently diagnosed patients, without any clinical fluctuations (group A), and 25 patients in a late phase of the disease with severe fluctuations in response to levodopa therapy (group B) were included in the study. Erythrocyte glutathione peroxidase was determined as a measure of antioxidant activity and significantly lower values were found in group B than in group A. Regression analyses in groups A and B showed significant correlation between glutathione peroxidase and duration of disease, but not between glutathione peroxidase and age of patients.

Aged↗
PubMed1990

Lipid peroxidation and antioxidant supplementation in old age.

An age-related rise in blood lipid peroxides measured by the thiobarbituric acid (TBA) method has been reported in several studies. Our study was designed to investigate whether this could be attributed to antioxidant deficiencies in aged individuals. We therefore measured the TBA-value of young and old women and related this to vitamin E and selenium status and the fatty acid composition, triglyceride and cholesterol content of platelet-poor plasma. A significant difference (p less than 0.001) between young and old women in the plasma TBA-value and the plasma lipid parameters was found. Old women had a lower selenium status than the young women (p less than 0.01), but their vitamin E status was fully adequate. Only the lipid parameters correlated significantly (p less than 0.001) with the TBA-value. In a 3-month placebo-controlled supplementation trial with vitamin E and selenium, the plasma TBA-value of the old women did not change. This study shows that the TBA-value of plasma is primarily determined by the fatty acid content and is not influenced by antioxidant supplementation in healthy individuals. The question of the sensitivity of the TBA-test is discussed.

Adult↗
PubMed1989

Adipose tissue levels of fatty acids and tocopherol in young and old women.

Tocopherol concentration and fatty acid composition were determined in samples of subcutaneous adipose tissue from 33 young and 28 old women. Young women exhibited more saturated fatty acids and less monounsaturated fatty acids than old women (p less than 0.01). Adipose tissue tocopherol correlated with plasma tocopherol, with r = 0.49 and p less than 0.01, when the data for young and old were combined. A negative association was found between adipose tissue tocopherol and the n-3/n-6 fatty acid ratio in the old women (r = 0.42; p less than 0.05), suggesting that the tocopherol content of adipose tissue is determined not only by the intake of the nutrient but also by the tissue fatty acid composition.

Adipose Tissue↗
PubMed1989

Selenium in rheumatoid arthritis. A historical prospective approach.

Time-dependent changes in serum selenium concentrations were studied in 28 patients with rheumatoid arthritis and the concentrations were related to disease activity. The mean length of the observation period was 7.3 years and a mean of 6 analyses was performed for each patient. Serum selenium fluctuated with disease activity in most patients and a relatively low concentration was recorded in periods of high disease activity. Gold treatment had no influence on the selenium concentrations and selenium levels measured within the first year of the disease were not demonstrated to have any prognostic significance.

Arthritis, Rheumatoid↗
PubMed1987

Glutathione peroxidase activity in patients with rheumatoid arthritis and in normal subjects: effects of long-term selenium supplementation.

The effects of dietary supplementation with selenium were studied in 6 patients with severe, active rheumatoid arthritis (RA) and in 6 healthy control subjects. Initial concentrations of Se in red blood cells and in serum, and the activity of the Se-dependent enzyme glutathione peroxidase (GSH-Px) in red blood cells, serum, and granulocytes were significantly lower in RA patients compared with controls. During Se supplementation, however, the differences in Se levels and in GSH-Px activity between the 2 groups disappeared, except that, in RA patients, GSH-Px activity in granulocytes increased but remained significantly lower than in controls.

Adult↗
PubMed1986

Selenium status in Europe--human data. A multicenter study.

In order to examine the levels of serum selenium in Europe, a collaborative study was conducted under the auspices of "The Working Group on Diet and Cancer" under "The European Organisation for Cooperation in Cancer Prevention Studies". A total of 502 serum samples was obtained from healthy, non-institutionized individuals, aged between 20 and 65 years, from 17 locations in 10 different countries in Europe. The selenium content of the samples was determined by a fluorometric method. All analyses were performed in one laboratory. Mean +/- standard deviation of the serum selenium given in microgram/l for the combined male and female data from the individual regions was: Belgium: 100 +/- 9; Denmark: Aarhus 78 +/- 15; France: Grenoble 79 +/- 15; Paris 82 +/- 11; W. Germany: Bavaria 70 +/- 10 Giessen 68 +/- 10, Heidelberg 76 +/- 9; Greece 63 +/- 14; Netherlands: 93 +/- 12; Portugal: Lissabon 102 +/- 10; Spain: Barcelona 87 +/- 14; Sweden: Göteborg 77 +/- 11, Malmö 90 +/- 14, Umeå 82 +/- 8, Uppsala 81 +/- 15; United Kingdom: Ipswich 107 +/- 13, London 109 +/- 14. None of the values represented toxic or overt deficiency levels.

Adult↗
PubMed1985

Selenium inhibits UV-light-induced skin carcinogenesis in hairless mice.

Female hairless inbred hr/hr mice were exposed to UV-B irradiation from Philips TL 40W/12 fluorescent tubes. Fractionated irradiation, given as single daily doses 5 days a week, was gradually increased from 0.04 to 0.4 J/cm2 over 2 weeks. Irradiation at 0.4 J/cm2 was continued for 20 weeks. Selenium supplementation given as sodium selenite in the drinking water at 2, 4 and 8 mg/l began 3 weeks before UV-irradiation and continued thereafter. Development of skin tumors was followed by weekly examinations. Statistical analyses revealed significant dose-dependent selenium-mediated protection against UV-light-induced skin cancer. Leukemia developed in 5 of 150 UV-irradiated mice as opposed to none in a group of 60 unirradiated mice.

Animals↗
PubMed1985

Selenium treatment in rheumatoid arthritis.

A low selenium level has been reported in rheumatoid arthritis and juvenile chronic arthritis. Selenium is an essential part of the enzyme glutathione peroxidase, which catabolizes peroxides, compounds which are suggested to be of pathogenetic importance in rheumatic diseases. To assess a possible antirheumatic effect of selenium, 40 patients with active RA were included in a 6-month double-blind clinical study of selenium versus placebo. The patients in the selenium group were given daily supplements of 256 micrograms selenium in selenium-enriched yeast. Although concentrations of selenium in serum and erythrocytes increased considerably, no significant antirheumatic effect of selenium could be demonstrated.

Arthritis, Rheumatoid↗
PubMed1985

Low selenium level in severe rheumatoid arthritis.

Serum selenium concentrations were measured in 87 patients with rheumatoid arthritis. The serum selenium levels of the whole group of patients was significantly reduced (70.2 +/- 13.3 micrograms/l, p less than 0.001) when compared with the reference material (79.8 +/- 10.6 micrograms/l). However, the reduction was not equally pronounced in three groups of patients representing different courses of the disease. One group with an active, disabling disease of long duration had a very reduced serum selenium level (63.7 +/- 14.1 micrograms/l, p less than 0.001). Another group, with a protracted but mild disease had a slightly reduced level (74.1 +/- 10.8 micrograms/l, p less than 0.01), and a group with mild disease of short duration had a slightly but not significantly reduced selenium level (75.9 +/- 10.8 micrograms/l, p less than 0.1). Significant correlation was found between serum selenium and the number of joints with limitation of motion, number of joints with active arthritis, haemoglobin concentration and IgG concentration. No correlation was found between serum selenium and disease duration, morning stiffness, ESR, C-reactive protein, rheumatoid factor titre, serum albumin, IgM and IgA. Selenium is part of the enzyme glutathione peroxidase that catabolizes peroxides which are suggested to be actively involved in inflammation. A low selenium level may thus be a further factor in the pathogenesis of rheumatoid arthritis.

Adult↗