வைட்டமின்கள் மற்றும் தாதுக்கள்

Previously, we reported that obese Zucker rats had increased susceptibility to DMBA-induced mammary tumors compared to lean Zucker rats. In that experiment, 36% of the obese ovariectomized rats developed mammary tumors while lean ovariectomized rats developed no mammary tumors. The obese sham-operated rats developed mammary tumors (59%) compared to 30% of the lean sham-operated rats. On the other hand, several lines of evidence suggest that lower serum selenium (Se) may play an important role in increasing the risk of several types of cancers (e.g., colon, breast and prostate cancers). In the present study, we used this Zucker rat model to examine the effect of obesity on Se status, and the serum Se level was determined by graphite furnace atomic absorption spectrometry. We found that the serum Se levels did not differ by ovariectomy when comparing the combined sham-operated groups with the combined ovariectomized groups; similarly, there was little difference among the four sub-groups. However, obesity decreased the serum Se levels in the combined obese groups (480 ± 10.9 ng/ml) when compared with the combined lean groups (511 ± 10.3 ng/ml) (P<0.05). In summary, our data demonstrate for the first time that obesity decreases serum Se levels in an animal model and suggest that serum Se may play an important role mammary carcinogenesis.

β-Carotene, a potent provitamin A carotenoid having multifaceted physiological activities, could ameliorate the different types of abnormal behaviour in rats after the administration of heroin. The administration of different dosesof heroin, viz LD25, LD50 showed various degrees of abnormal conditions and behaviours such as depletion of body weight, retinol reserve, decrease of water intake, piloerection, drowsiness, wet shakes, restlessness and jumping etc.β-carotene accounts for the amelioration of the above conditions and abnormal behaviour to a certain extent alongwith restoration of the retinol level in the liver of albino rats receiving heroin of different doses.

The total contents of lead, arsenic, mercury, chromium, cadmium, zinc, copper, molybdenum and nickel were determined in soils collected from mining and agricultural areas around the molybdenum mine in Liaoning Province, China. The distribution, chemical fractions and ecological risks of heavy metals in soils were investigated and assessed. It was found that: the degrees of warning for all soils, both mining industry areas and agricultural areas, were serious warning. The results meant that all soils were contaminated seriously by heavy metals. The observed scheme of chemical fractions for heavy metals in soils of different sites was as follows commonly: residual>oxidable> reducible>acid soluble. The sources of heavy metals in top soils around the mine were as follows: dust fall, residue in the open air, higher background in soil-forming process, accompaniment element, automobile exhaust, wear of tires and brakes, release of heavy metals from ore tailing, the application of pesticides and irrigation with wastewater.

Vitamin D has been of increased interest in the role of maintaining immune system balance. Alopecia Areata (AA) is a T-cell mediated autoimmune disease which causes anagen-stage hair follicles. Low concentration of vitamin D may be a risk factor for AA. We aimed to determine vitamin D concentrations in patients with AA. 25-hydroxyvitamin D (25(OH)-D) concentrations and 1,25 dihydroxyvitamin D3 (1,25(OH)2D3) were determined from sera collected from patients with AA (n=42) and healthy controls (n=42). 25(OH)-D and 1,25(OH)2D3 concentrations were measured by ELISA method. The concentrations of both 25(OH)-D and 1,25(OH)2D3 were found to be significantly lower in patients with AA than control group (p<0.001 for each analysis). The results show that there is a significant difference between AA patients and normal subjects in terms of serum vitamin D concentrations. Therefore, it is suggested that vitamin D deficiency may have a role in the setting of AA.

As the 21st most abundant element in earth’s crust, chromium has been extensively used in industrial activities such as paint pigments and leather tanning. As a consequence, there is a continual influx of chromium contaminants into the environment, thereby posing a serious environmental problem. Chromium exhibits a wide range of possible oxidation states, where trivalent chromium [Cr (III)] is most stable energetically, but Cr (III) and Cr (VI) are most commonly observed in aquatic environment. Cr (VI) species are of great environment concern due to their well-known toxicity, carcinogentic properties and high mobility in environmentally relevant media. Cr (III) is generally regarded as benign and even essential for human and animal, since trace amounts of Cr (III) is required for sugar and lipid metabolism.In this context, it is a common strategy in environmental remediation to reduce toxic Cr (VI) to Cr (III) by various redox reactions. Cr (III) is thought to be immobilized by precipitating into insoluble Cr (III) hydroxides