Assessment of the iodine status of the Wa national boarding school students in Southwest China.

Iodine deficiency disorder (IDD) has been recognized as a major public health problem worldwide and has serious detrimental effects on the growth and development of the children. Therefore, monitoring the iodine status of the school-aged children is of great importance. We randomly recruited 159 boarding school students (aged from 6 to 14) from 10 primary schools in Lincang County, Yunnan Province. The dietary iodine level of the students was measured by the new mixed meal method and chemical analysis. Fifty-seven daily water samples and 32 salt samples were collected from the same surveyed area to determine the iodine content using the sulfate cerium catalytic spectrophotometric method and the hyposulphite quantitative titration method, respectively. The iodine level of each water sample was ranged from 0.611 to 1.473 µg/L. The median and the mean value of the iodine content in water were 0.972 and 0.979 ± 0.189 µg/L. The average iodine intake of each age group was higher that the recommended nutrient intakes (RNI) but lower than the tolerable upper intake level (UL). The median and the mean value of the iodine content in salt were 25.53 and 25.62 ± 1.70 mg/kg. Taken together, the present study investigated the iodine intake status of Wa school-aged children through examination of their dietary iodine intake, the environment, and the salt iodine status. Results showed that the status of the iodine uptake of the Wa children were higher than the RNI, but lower than the UL.

Simulated microgravity-induced oxidative stress in different areas of rat brain / 生理学报

Microgravity is known to produce a number of neurological disturbances during space flight; however, the underlying mechanism of these disturbances is yet to be elucidated. There have been some reports about the increased oxidative stress under microgravity or simulated microgravity. In the present study, we investigated the process of oxidative stress induced by simulated microgravity in different areas of rat brain, which may shed light on the mechanism of neurological disturbances and further neuroprotective research in spaceflight. After adaption for 7 d, 40 healthy male Sprague-Dawley rats were matched for body weight and randomly assigned to control groups (7, 14, 21 and 28 d) and tail-suspended simulated microgravity groups (7, 14, 21 and 28 d). The tail-suspended groups were treated with 30 angels of tail suspension and the control groups were treated similarly to the tail-suspended groups but without tail suspension. After the required times, different structures of rat brain, including cerebellum, cerebral cortex and hippocampus, were harvested and frozen for the further determination. Griess assay, thiobarbituric acid reactive substance (TBARS) assay, competitive ELISA and ferric reducing ability of plasma (FRAP) assay were used for the observation of the changes of reactive nitrogen species (RNS), malondialdehyde (MDA), nitrotyrosine (NT) and total antioxidant capacity (TAC), respectively. As shown in the results, there were different changes in various brain regions after tail suspension compared with control groups. (1) In cerebellum, NT increased after 7 d tail suspension, decreased after 14 d and increased again after 28 d; MDA increased after 14 d; RNS increased and TAC decreased after tail suspension for 21 d; (2) Increase of NT after14 d tail suspension, increase of MDA and decrease of TAC after 21 d were found in cerebral cortex; (3) In hippocampus, RNS increased after tail suspension for 7 d, decreased after 14 d and increased again after 28 d; MDA increased after 21 d; NT increased after 28 d; TAC increased after 7 d and recovered after 21 d. These results suggest that simulated microgravity induced by tail suspension increases the level of oxidative stress in rat brain; however, there are different features in different areas of rat brain. During the response to simulated microgravity, rat brain tissues present a similar process from adaptive response to irreversible oxidative damage.