Are lens opacities related to plasma selenium and glutathione peroxidase in man?
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Aged↗
Biomedical subjects
B Akesson
Publications and source records attributed to B Akesson.
Low plasma selenium as a risk factor for cancer death in middle-aged men.
In a population study, 10,000 men (aged 46-48 years) were invited to a health screening program. At follow-up, which was up to eight years later, 61 subjects had died from cancer; from 35 of these subjects, plasma samples were available that were obtained at the initial screening. These samples, together with samples from two living controls for each case, were analyzed for selenium, retinol, cholesterol, triglyceride, and a number of plasma proteins. Plasma selenium was significantly lower (p less than 0.05) in cases than in controls (means: 1.06 vs. 1.12 mumol/l). The proportion of cases increased significantly from the highest to the lowest quintile of plasma selenium, and the relative risk for cancer death was 3.8 times higher in the lowest quintile compared with the highest. Mean plasma retinol was similar in cases (2.53 mumol/l) and controls (2.56 mumol/l). Cases and controls also had similar values for plasma cholesterol, triglyceride, uric acid, apolipoprotein B, orosomucoid, prealbumin, retinol-binding protein, and beta 2-microglobulin. Apolipoprotein AI in plasma was lower among cases (p less than 0.025). Cases smoked significantly more than controls did (p less than 0.05). Data indicate that low plasma selenium was a risk factor for cancer death in middle-aged men who lived in the same area. Further studies are necessary to establish whether differences in selenium intake, selenium metabolism, or other factors related to selenium are responsible for the relations observed. At present, the available data do not justify selenium supplementation programs in the whole population.
Apolipoprotein A-I↗
A mixed endocrine adrenal tumour causing steatorrhoea.
A 60 year old man developed steatorrhoea, weight loss, mild diabetes mellitus, labile hypertension and limb cramps. Raised plasma concentrations of catecholamines, particularly noradrenaline and a computed tomography-scan showing an adrenal tumour strongly suggested a pheochromocytoma. Adrenoreceptor blockade reversed the symptoms, decreased faecal fat, and increased duodenal trypsin to normal concentrations. After adrenalectomy the patient was asymptomatic and there was no steatorrhoea. The blood glucose concentrations became normal. Immunocytochemistry revealed the tumour cells to store large amounts of enkephalin and somatostatin reactive material and moderate amounts of immunoreactive beta-endorphin and dynorphin.
Adrenal Gland Neoplasms↗
Absorption and lymphatic transport of exogenous and endogenous arachidonic and linoleic acid in the rat.
[3H]Arachidonic (20:4) and [14C]linoleic acid (18:2) were fed to thoracic duct-cannulated rats in test meals of either tracers alone, cream, Intralipid, pure arachidonic acid, or pure linoleic acid. Less [3H]20:4 than [14C]18:2 was recovered in chyle during the first 5 h. After cream feeding, the proportion of radioactivity found in phospholipids was high and increased during the first 3 h. After the meal (3-5 h) 61 +/- 6% of the 3H and 57 +/- 10% of the 14C was in phosphatidylcholine, and 11 +/- 3% of the 3H and 3.0 +/- 4% of the 14C was in phosphatidylethanolamine. Changing the fat vehicle to Intralipid or pure 18:2 decreased the proportion of label in the phospholipids and increased the 3H and 14C radioactivity in the triacylglycerol fraction, the distribution of 14C being influenced more than that of 3H. After feeding the tracers in 200 microliters of pure 20:4, greater than 90% of both isotopes was in triacylglycerol. During fasting, triacylglycerol transported 56% (0.7 mumol/h), phosphatidylcholine transported 34% (0.4 mumol/h), and phosphatidylethanolamine transported 10% (0.1 mumol/h) of the 20:4 mass. After cream or Intralipid feeding, the output of 20:4-containing phosphatidylcholine and phosphatidylethanolamine increased 2.1- to 2.8-fold, whereas the transport of 20:4 with triacylglycerol remained constant. Phospholipids thus became the predominant transport form for 20:4. After feeding 200 microliters of 20:4, the intestine produced, however, 20:4-rich triacylglycerols that transported 89% of the chyle 20:4.
Animals↗
Effect of dietary fish on plasma selenium and its relation to haemostatic changes in healthy adults.
Since fish is a food rich in selenium in Sweden, selenium status among healthy adults was studied after a change to a diet containing 150-200 g of fish per day. In two experiments the fish diet was maintained for 6 and 11 weeks. The mean increase in plasma selenium was 0.13 mumol/l (13%). Most of the increase was evident already after 3 weeks. In previous studies of the same individuals this diet caused a delay in primary haemostasis and a decrease in platelet aggregability. There was no apparent temporal relationship between the increase in plasma selenium and the increase in bleeding time and the proportion of eicosapentaenoic acid in platelet or plasma phosphatidylcholine. Further analysis is necessary to distinguish the effects of fish fatty acids and selenium on haemostatic functions.
Adenosine Diphosphate↗
Plasma selenium and glutathione peroxidase in relation to cancer, angina pectoris and short-term mortality in 68-year-old men.
Plasma selenium and plasma glutathione peroxidase were measured in 483 68-year-old men participating in a longitudinal population study, in which the probands were representatively selected. The prevalence of cancer and coronary heart disease was assessed by a structured interview. In plasma the concentration of selenium was 1.08 +/- 0.18 mumol X l-1 and the activity of glutathione peroxidase 540 +/- 90 mumol X l-1 X min-1. Plasma selenium was correlated to glutathione peroxidase activity (r = 0.49, p less than 0.001), but not significantly to plasma albumin levels (r = 0.18). Plasma selenium and glutathione peroxidase values in subjects with cancer or angina pectoris were not significantly different from those in subjects without these diseases. Plasma selenium concentration and glutathione peroxidase activity in the subjects who died within 1 year of screening were 89% and 88%, respectively, of the values among survivors (p less than 0.01). For the subjects who died during the second year after screening, these variables did not differ significantly from the values among survivors, 97% and 99%, respectively. Since the relation of low selenium and glutathione peroxidase to mortality was observed only for the first year, it was probably due to a disturbed nutritional state prior to death, rather than to a long-term negative influence of low plasma selenium on the mortality risk. Furthermore, the data have failed to demonstrate a relationship between selenium status and cancer or angina pectoris.
Aged↗
Intestinal xylose degradation and bile acid deconjugation in patients with continent or conventional ileostomy.
Intestinal bacterial overgrowth was investigated in ten patients with continent ileostomy and in eight with conventional ileostomy, using the bile acid deconjugation test and the (14C)xylose test. Bile acid deconjugation was significantly greater in the continent ileostomy than in the conventional ileostomy group. There was a positive correlation between fecal 14C after oral administration of cholyl-(14C)glycine and the extent of bile acid deconjugation, suggesting that deconjugation occurred in the distal ileum. There was no difference in (14C)xylose degradation rate between the two groups of patients, supporting the view that the (14C)xylose breath test reflects microbial activity in the proximal small intestine.
Adult↗
Visual disturbances after industrial triethylamine exposure.
Among 19 workers in a polyurethane foam production plant, visual disturbances ("foggy vision", "blue haze", and sometimes halo phenomena) were reported on a total of 47 occasions by five workers over 11 weeks. The symptoms were associated with triethylamine exposure. Time-weighted average levels of 12 to 13 mg/m3 were recorded at work operations associated with symptoms, and 4 to 5 mg/m3 at other tasks. Twice as high peak levels were recorded. A detailed medical examination of the five affected workers in a free interval did not reveal any signs of permanent eye disease.
Adult↗
Selenium status in patients with liver cirrhosis and alcoholism.
1. Selenium status and blood levels of other nutrients related to lipid peroxidation were studied in patients with advanced alcoholic liver cirrhosis, in male alcoholics who had been abstinent for at least 1 month and in healthy control subjects. 2. Plasma Se was decreased in alcoholic cirrhosis but not among alcoholics in abstinence. Platelet glutathione peroxidase (EC 1.11.1.9; GSH-Px) activity was decreased in cirrhotic patients, whereas GSH-Px in blood and plasma was the same as in controls for both groups of patients. 3. Plasma retinol and plasma alpha-tocopherol were decreased in alcoholic cirrhosis, whereas plasma ascorbic acid was the same in all groups. 4. The decreases in platelet GSH-Px, plasma Se and alpha-tocopherol indicate a deranged antioxidant defence in patients with advanced alcoholic cirrhosis, but the levels of these and other nutrients were generally not correlated to common clinical chemical indicators of liver disease.
Adult↗
Selenium content of breast milk sampled in 1978 and 1983 in Sweden.
Selenium in human milk sampled at different intervals after parturition was analyzed on two occasions five years apart. The selenium content of colostrum and transitional milk was higher than that of mature milk. Mature milk sampled in 1983 contained more selenium than mature milk sampled in 1978 (11.9 (0.8) vs. 9.4 (0.5) micrograms/l, mean (SD), p less than 0.01). The selenium and protein content in milk were positively correlated, which may be explained by the occurrence of seleno-amino acids in proteins. The selenium content was not correlated to that of tocopherol or of highly unsaturated fatty acids in mature milk. The values for the selenium content in human milk found here are lower than those previously reported from other countries.
Fatty Acids, Unsaturated↗
Determination of N-methylmorpholine in air samples from a polyurethane foam factory. Comparison between two methods using gas chromatography and isotachophoresis for analysis.
The N-methylmorpholine levels in workroom air in a polyurethane foam factory were determined by two methods in which midget impinger flasks were used for sampling. The analyses were performed by gas chromatography and isotachophoresis. The values obtained by the gas chromatographic method were 19% higher than those of the isotachophoretic method. Determinations of the amine in samples generated in laboratory experiments showed no statistical difference between the two methods. The mean air concentrations of N-methylmorpholine in different work areas of the factory ranged from 7 to 22 mg/m3. Urine was collected from seven workers and analyzed for N-methylmorpholine by gas chromatography. The amine concentrations and the excretion rates increased considerably during the workday.
Air Pollutants, Occupational↗
Nutritional status in girls with juvenile chronic arthritis.
Nutritional status, with emphasis on nutrients involved in inflammatory processes, was investigated in 26 girls with juvenile chronic arthritis (JCA) and in healthy controls. Children with JCA had decreased plasma selenium compared to controls. Glutathione peroxidase activity in plasma was similar in both groups but the activity in blood was slightly depressed in JCA. The decrease in blood glutathione peroxidase was more pronounced in patients with high to medium disease activity. Ascorbic acid was measured in plasma, platelets, mononuclear cells and granulocytes. A slight decrease in granulocyte ascorbic acid was observed in patients but in plasma, platelets and mononuclear cells no difference was observed. Serum alpha-tocopherol, blood folate and serum cobalamine was the same in both groups. Several patients, especially in the youngest group, exhibited impaired growth. Serum creatinine and arm muscle circumference were lower in the arthritic patients indicating a lower muscle mass. These changes were more pronounced in patients with systemic or polyarticular onset of the disease. The possibility that the changes in nutritional status in patients with JCA can be corrected by dietary supplementation needs further investigation.
Adolescent↗
Exposure in welding of high nickel alloy.
Nickel (Ni) levels in air during welding of high-Ni alloy (75% Ni) were very high (mean 0.44 mg/m3, range 0.07-1.1 mg/m3; 20 person-days of measurements). In six welders the Ni level in urine after four weeks of vacation was slightly but statistically significantly enhanced as compared to ten unexposed controls (means 8.7 vs 5.1 micrograms/l; P less than 0.005). The level on Monday mornings increased somewhat during a period of six weeks of high-Ni alloy welding (mean 13 micrograms/l; P less than 0.05). The level was slightly higher Thursday afternoon (mean 18 micrograms/l; P less than 0.0001). The data indicate the existence of a very slow pool of Ni in the body in addition to a faster one. There was no correlation between Ni levels in air and urine. Thus, in spite of the very high Ni levels in air, urinary Ni levels were thus of little use for biological monitoring of exposure and risk during high-Ni alloy welding. All eleven welders studied reported one or more symptoms (irritation of upper airways, headache, tiredness) as occurring more often (P less than 0.006) during high-Ni welding than when welding ordinary stainless steel. Lung-functions studies were normal.
Adult↗
Gastrointestinal function in patients with progressive systemic sclerosis.
In 24 patients with progressive systemic sclerosis (PSS) the pentagastrin-stimulated gastric acid secretion was determined to investigate if acid hypersecretion is associated with reflux-oesophagitis--the most common complication to oesophageal involvement in PSS. Gastro-oesophageal reflux was observed in 12, reflux-oesophagitis in 9 and oesophageal mycosis in 8 patients. Gastric acid secretion was increased in 13 (54%) patients and tended to be higher in patients with oesophagitis. Patients with reflux and increased acid secretion seemed to be free from oesophageal mycosis. Bacterial overgrowth and malabsorption are known complications to intestinal scleroderma and these items were investigated using non-invasive methods. Four patients had increased bile acid deconjugation, 3 had increased (14C)xylose degradation indicating bacterial overgrowth and 7 patients had decreased fat absorption in the triolein breath test. Nutritional status with respect to selenium, folate, cobalamin and fat-soluble vitamins was essentially normal.
Adult↗
Selenium status in vegans and lactovegetarians.
Plasma and urinary selenium were determined among vegans, lactovegetarians and several groups of omnivorous subjects, using gas-liquid chromatography. Plasma Se was lower among lactovegetarians (0.80 (SD 0.18) mumol/l) than in the other groups (0.98 (SD 0.15) mumol/l). This was not related to Se intake, since the vegans had a lower and the lactovegetarians a higher intake of Se than omnivorous subjects in Sweden. Urinary Se was 0.36 (SD 0.10) mumol/d for controls, 0.17 (SD 0.10) mumol/d for vegans and 0.16 (SD 0.07) mumol/d for lactovegetarians. No relation between dietary Se and urinary Se was observed. Among vegetarians, plasma Se and urinary Se were correlated (r 0.51; P less than 0.05).
Adult↗
Phthalate ester exposure--air levels and health of workers processing polyvinylchloride.
Exposure to phthalic acid esters (PAE; mainly di-(2-ethylhexyl), diisodecyl and butylbenzyl phthalates) of workers in a polyvinyl chloride processing industry ranged from 0.02 to 2 mg/m3 in different job categories. The workers excreted slightly but significantly higher levels of PAE metabolites in urine than controls. In 54 workers studied clinically, there were no indications of peripheral nerve or respiratory system effects. Some biochemical tests were abnormal; these should be studied further.
Adult↗
Interaction between ascorbic acid and acetylsalicylic acid and their effects on nutritional status in man.
Healthy adults were given four diets, each one for one week: Low ascorbic acid diet, low ascorbic acid diet plus acetylsalicylic acid (3 g/d), high ascorbic acid diet (1 g/d) and high ascorbic acid diet plus acetylsalicylic acid. At low ascorbic acid intake, acetylsalicylic acid increased urinary ascorbic acid, but at high ascorbic acid intake, acetylsalicylic acid instead decreased urinary ascorbic acid. The latter effect was probably due to an inhibited intestinal absorbtion of ascorbic acid, and the former effect may reflect decreased protein binding and tissue uptake of ascorbic acid caused by acetylsalicylic acid. In no instance, acetylsalicylic acid affected plasma ascorbic acid. The effect of ascorbic acid on substances related to lipid peroxidation was investigated. The high ascorbic acid diets decreased plasma lipoperoxide and retinol binding protein. No change was observed in serum tocopherol, iron status, erythrocyte lipid fluorescence, plasma ceruloplasmin, urinary and plasma selenium and glutathione peroxidase activity. Thus, one-week supplementation of ascorbic acid seems to have only marginal effects on lipid peroxidation and antioxidant status.
Adult↗
Hepatotoxic effects of anti-rheumatic drugs in cultured rat hepatocytes.
Drug-induced liver injury has been suggested as a possible mechanism for the liver damage in rheumatic diseases. To evaluate the role of direct toxic action of drugs on hepatocytes, the effects of salicylate, chloroquine, prednisolone and indomethacin on LDH leakage from cultured rat hepatocytes were studied. Exposure for 24 h to the first two drugs induced liver damage, as reflected by LDH release, at concentrations 2-10 times as high as the therapeutic plasma levels in humans. Indomethacin and prednisolone at concentrations approx 50-100-fold higher than the therapeutic plasma levels, were not toxic to cultured hepatocytes. The data suggest that direct a toxic effect on hepatocytes is one possible mechanism of hepatotoxicity for salicylate and chloroquine, especially since the exposure time is much longer in humans than in the experimental model used here.
Animals↗