2,207 research outputs found

    Titanium dioxide nanoparticles oral exposure to pregnant rats and its distribution

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    Background: Titanium dioxide (TiO2) nanoparticles are among the most manufactured nanomaterials in the industry, and are used in food products, toothpastes, cosmetics and paints. Pregnant women as well as their conceptuses may be exposed to TiO2 nanoparticles; however, the potential effects of these nanoparticles during pregnancy are controversial, and their internal distribution has not been investigated. Therefore, in this study, we investigated the potential effects of oral exposure to TiO2 nanoparticles and their distribution during pregnancy. TiO2 nanoparticles were orally administered to pregnant Sprague-Dawley rats (12 females per group) from gestation days (GDs) 6 to 19 at dosage levels of 0, 100, 300 and 1000 mg/kg/day, and then cesarean sections were conducted on GD 20. Results: In the maternal and embryo-fetal examinations, there were no marked toxicities in terms of general clinical signs, body weight, food consumption, organ weights, macroscopic findings, cesarean section parameters and fetal morphological examinations. In the distribution analysis, titanium contents were increased in the maternal liver, maternal brain and placenta after exposure to high doses of TiO2 nanoparticles. Conclusion: Oral exposure to TiO2 during pregnancy increased the titanium concentrations in the maternal liver, maternal brain and placenta, but these levels did not induce marked toxicities in maternal animals or affect embryo-fetal development. These results could be used to evaluate the human risk assessment of TiO2 nanoparticle oral exposure during pregnancy, and additional comprehensive toxicity studies are deemed necessary considering the possibility of complex exposure scenarios and the various sizes of TiO2 nanoparticles

    Antioxidant effect of lidocaine and procaine on reactive oxygen species-induced endothelial dysfunction in the rabbit abdominal aorta

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    Background: Reactive oxygen species (ROS) induce lipid peroxidation and tissue damage in the endothelium. We tested the antioxidant effect of lidocaine and procaine on ROS-induced endothelial damage in the rabbit aorta. Methods: Aortic rings isolated from rabbits were suspended in an organ bath filled with Krebs-Henseleit (K-H) solution bubbled with 5% CO2 and 95% O 2 at 37.5??C. After precontraction with phenylephrine (PE, 10 -6 M), changes in tension were recorded following a cumulative administration of acetylcholine (ACh 3 ?? 10-8 to 10 -6 M). Differences were measured as percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS as generated by electrolysis of the K-H solution. The aortic rings were pretreated with lidocaine or procaine (10-5 M to 3 ?? 10-3 M) to compare their effects, as well as ROS scavengers, catalase, mannitol, sodium salicylate, and deferoxamine, and a catalase inhibitor, 3-amino-1,2,4-triazole (3AT). Results: Lidocaine and procaine dose-dependently maintained endothelium-dependent relaxation induced by ACh despite ROS activity (P < 0.05 vs control value). The 3AT pretreated procaine (3 ?? 10-3 M) group decreased more significantly than the un-pretreated procaine group (P < 0.05). Conclusions: These findings suggest that lidocaine and procaine dose-dependently preserve endothelium-dependent vasorelaxation against ROS attack, potentially via hydrogen peroxide scavenging. Copyright ?? Korean Society of Anesthesiologists, 2010

    The Effect of Resistance and Balance Training on Postural Control and Physical Fitness in Adults with Down Syndrome

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    Abstracts PURPOSE This study aimed to examine the effects of resistance and balance training on physical function and postural control in individuals with Down syndrome (DS). METHODS Ten adults with DS constituted the experimental group (EX) and attended an 8-week resistance and balance training program. The results were compared with those of the control group (CON), which consisted of 10 patients who did not undergo any physical training. Body composition, postural stability, and physical fitness were measured before and after the training program. Resistance and balance training were performed for 60 minutes, three times a week for 8 weeks. RESULTS Body weight, body mass index, body fat percentage, and waist circumference decreased significantly in the EX group after completing the 8-week resistance and balance training program. The center of pressure and the difference between standing foot pressure on the left and right were significantly improved in the EX group. Physical fitness including sit-to-stand repetitions and 10 m shuttle duration significantly improved in the EX and CON groups. CONCLUSIONS These results suggest that resistance and balance training to improve musculoskeletal problems is an effective strategy to prevent injury, fatigue, and falls during exercise and to improve general health in individuals with DS
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