Urinary selenium excretion in patients with cervical uterine cancer

In this work, we report on a relationship between urinary selenium and the development of cervical uterine cancer. A simple chemical method was developed to concentrate trace amounts of selenium from relatively large urine samples by use of small activated carbon filters. When these filters are irradiated with thermal neutrons, selenium can be determined either by ^77mSe (t _1/2=17.5 s) or ⁷⁵Se (t _1/2=120 d). In this article, we report the results for 82 urine samples from women with cervical uterine cancer in several stages of development and from healthy controls. These results show a statistically significant increase of selenium excretion in cancer patients as compared to controls. Urinary selenium excretion is highest for patients in the intermediate stages of the disease.     

Urinary selenium in healthy and diabetic Saudi Arabians

We examined Se in urine of 170 Saudi Arabian diabetics (19 insulin-dependent [type 1] and 151 insulin-independent [type 2]) and in an equal number of control subjects of the same origin by measuring the ratio of the concentration of this metal (C_Se) to that of creatinine in urine (C_creat) for each subject. The mean (and SEM) of C_Se/C_creat for the control subjects was 56 (2.9) μmol/mol creat, whereas, the value for the diabetics combined or separated into type 1 and type 2 was 56.7 (3.2), 51.5 (6.3), and 57.4 (3.5) μmol/mol creat, respectively. With the exception of type 2 diabetics who were treated with insulin in addition to oral hypoglycemic and diet (35 patients) (mean [SEM]=43 (4.3) μmol/mol creat), there was no significant difference in C_Se/C_creat between the diabetics and control subjects. Also, there was no significant correlation between C_Se/C_creat and age, sex, or weight of diabetics, whereas, the correlation with the degree of diabetic control was significant (p≤0.0136). Of all diabetes-associated disorders (cardiovascular diseases, neuropathy, ophthalmologic diseases, infections, and hepatic disease), only ophthalmologic diseases appears to cause a significant (p≤0.05) reduction in C_Se/C_creat, but only among type 2 diabetics. Inasmuch as Se status is reflected by urinary Se, healthy Saudi Arabians appear to have Se status that is comparable or higher than those reported for other populations.     

Urinary steroid excretion rates in acromegaly

Using gas chromatography/mass spectrometry, urinary excretion rates of cortisol, cortisone and of various steroid metabolites were determined in 35 acromegalic patients (18 men, 17 women) and in 45 age- and weight-matched controls. The ratio of excreted cortisol/cortisone was similar in acromegalics (0.75 +/- 0.20) and in controls (0.75 +/- 0.24). Hence, the preponderance of the main cortisone-derived metabolite, tetrahydrocortisone, over the main metabolites of cortisol (tetrahydrocortisol and allotetrahydrocortisol; p < 0.01), which was seen both in female and in male acromegalics and which was directly correlated with the postglucose concentrations of growth hormone (r = 0.508, p < 0.01), suggests a decreased activity of 11beta-hydroxysteroid dehydrogenase type 1 in acromegaly. Furthermore, the preponderance of etiocholanolone over androsterone (p < 0.01) in men (though not in women) with acromegaly--the ratio androsterone/etiocholanolone being negatively correlated with the serum concentrations of insulin-like growth factor type 1 (r = -0.406, p < 0.05)--suggests a relatively reduced activity of hepatic 5alpha-reductase in male acromegalics.     

Urinary excretion of taurine in epilepsy

Evidence that taurine (2-aminoethanesulfonic acid) is related to the epilepsies is supported by work with both experimental animals and hurmans. It may function as a neurotransmitter or modulator of neurotransmission. Investigators using an automated amino acid analyzer reported lower mean urinary taurine excretion among epileptics. However, Rao et al. reported higher taurine excretion among epileptics using an older method. Analyses of the same epileptic and control urines by both methods coupled with paper and molecular size chromatography indicate that substances in addition to taurine are co-eluted with taurine using the older method, yielding spuriously high values. The resolution of this disparity is important because the urinary excretion of taurine may reflect primarily the influence of taurine transport alleles which may be polygenic components in the idiopathic epilepsies.     

Urinary catecholamine excretion in aging]

In ageing female subjects, the urinary noradrenaline excretion (UNA) is reduced with respect to the controls in young adults. On the other hand the ratio UNA/clearance of endogenous creatinine increases with ageing. This provides a confirmation of the fact that ageing is associated with an increase in plasma noradrenaline. The ratio UA/clearance of creatinine remains unaltered. So far the physiological meaning of these results remains unclear.     

Influence of selenium and zinc on performance,blood constituents,and immune response in stressed calves

Eighty weanling beef calves were used to determine the effects of zinc and selenium supplementation on performance, immune response, and blood characteristics during stress. Treatments included: (1) control; (2) control diet with selenium injection [15 mg/hd (head)] (3) zinc diet (25 mg Zn/hd/d, added as ZnO); and (4) zinc diet with selenium injection. Feed intake and weight gains were not affected by zinc throughout the 28-d study. However, selenium improved weight gains in calves with low initial selenium status in the first 14 d of the study. Glutathione peroxidase (GSH-Px) was increased by selenium and decreased by zinc on d 19. Zinc appeared to interfere with the role of selenium in GSH-Px activity at the cellular level. Plasma zinc was not affected by treatment. Zinc supplementation resulted in increased serum sodium and decreased serum total protein and glutamic-oxaloacetic transaminase. Immune response was measured via antibody titers to Infectious Bovine Rhinotracheitis (IBR) and Para-influenza₃ (PI₃) viruses 19 d postvaccination. Levels of titers were not affected by either zinc or selenium, however, titers did reflect a response to vaccination between sampling dates. On d 19, zinc increased the percentage of leukocytes that were monocytes. Total leukocyte, neutrophil and lymphocyte numbers did not differ across treatments. These results suggest that selenium or zinc supplementation may individually improve an animal’s response to stress.     

Urinary selenium and iodine during pregnancy and lactation

The New Zealand environment is low in selenium and iodine, and is therefore ideally suited for the study of these anionic trace elements. The aim of this study was to determine urinary excretion of selenium and iodine during pregnancy and postpartum as part of an investigation of the influence of pregnancy and lactation on selenium metabolism in women of low selenium status. In a double-blind placebo-controlled study, 35 women in the earliest stages of pregnancy and 17 non-pregnant women were recruited in Dunedin, New Zealand. Eighteen pregnant women received 50 μg selenium as L-selenomethionine, while the others received a placebo daily during pregnancy and 12 months postpartum. The non-pregnant women received the supplement, serving as a positive control. Blood samples and twenty-four hour urine samples were collected monthly during pregnancy and at 3, 6, and 12 months postpartum for analysis of selenium and iodine. Selenium content in plasma and urinary excretion of selenium fell during pregnancy; however, total excretion of selenium was greater during pregnancy than postpartum. Urinary iodine excretion was much lower than reported previously in New Zealand. Due to large intra- and inter-subject variability, no trends in iodide excretion were observed. Factors which influence urinary excretion of selenium include dietary intake, but more closely, plasma concentrations of selenium (which is probably related to total selenium pool), creatinine excretion and therefore lean body mass, and glomerular filtration rate. The exact mechanism and sequence of events remains unclear and future studies incorporating new speciation techniques are necessary.     

Dynamic pathways of selenium metabolism and excretion in mice under different selenium nutritional statuses

The selenoprotein, cellular glutathione peroxidase (cGPx), has an important role in protecting organisms from oxidative damage through reducing levels of harmful peroxides. The liver and kidney in particular, have important roles in selenium (Se) metabolism and Se is excreted predominantly in urine and feces. In order to characterize the dynamics of these pathways we have measured the time-dependent changes in the quantities of hepatic, renal, urinary, and fecal Se species in mice fed Se-adequate and Se-deficient diets after injection of (82)Se-enriched selenite. Exogenous (82)Se was transformed to cGPx in both the liver and kidney within 1 h after injection and the synthesis of cGPx decreased 1 to 6 h and continued at a constant level from 6 to 72 h after injection. The total amount of Se associated with cGPx in mice fed Se-deficient diets was found to be less than in mice fed Se-adequate diets. This finding indicated that cGPx synthesis was suppressed under Se-deficient conditions and did not recover with selenite injection. Excess Se was associated with selenosugar in liver and transported to the kidney within 1 h after injection, and then excreted in urine and feces within 6 h after injection. Any excess amount of Se was excreted mainly as a selenosugar in urine.