Effect of rhBMP-2 on the Osteogenesis of Osteoblast Compounded Chitosan / 中国生物工程杂志

Recombinant human BMP-2 was compounded with chitosan/gelatin/hydroxyapatite(HCG) scaffold and the complex was sterilized by 60Co radiating. Osteoblast isolated from cranial bones of newborn rat was primary cultured and seeded onto the complexes. 3 days after culturing, scanning electron microscope(SEM) was applied to detect the compatibility of the cell with the complex. SEM showed osteoblast attached closely with the complex and grew well in its pores. Then the complexes with osteoblast modification were implanted into athymic nude mice subcutaneously. 8 weeks after implantation, X-ray photograph and histological observation were applied to detect the bone formation of the complexes. Under X-ray a high-density areas consistent with the shape of the implanted complex could be seen. Histological observation also proved there was bone formation in the interspace of the complex. A conclusion was drawn that rhBMP-2 compounded HCG scaffold had good osteogenesis ability in vivo.

Effects of various iodin-nutritional on activity of T4 5'-and 5-deiodinase in rat brain / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the changing of T4 5'-and 5-deiodinase within rat brain under various iodin-nutritional states.</p><p><b>METHODS</b>Animal model of iodine-deficiency rat was performed and the rats were divided into 4 groups by the intake of iodine-nutrition, and then killed at an age of 20 days. The thyroid hormones level in serum was measured by ELISA and the activity of T(4) 5'-and 5-deiodinase within brain was analyzed.</p><p><b>RESULTS</b>In less-iodine (LI) group,TT4 and FT4 were accounting for 3.5% of the neutral-iodine (NI) group's, and FT3 was 174.0% of NI group's (P < 0.05). In NI group,TT4 and FT4 were 114.5% and 127.7% of NI group's (P < 0.05). In high-iodine (HI) group, TT4 and FT4 were 61.86% and 62.0% of NI group's, and FT3 was 184.9% of NI group's (P < 0.05). In LI group, the activity of T4 5'-deiodinase tissue of per gram (1.95 +/- 0.32) ngT3.microgT4(-1).h was significantly higher than that of NI group (P < 0.05), and the activity of 5-deiodinase (1.38 +/- 0.21) ngrT3.microg T4(-1).h(-1) is significantly less than that of NI group (1.59 +/- 0.23) (P < 0.05). In HI group the activity of T4 5'-and 5-deiodinase tissue of per gram (1.12 +/- 0.19 and 1.73 +/- 0.36) ngrT3.microgT4(-1).h(-1)was significantly less than that of NI group (P < 0.05).</p><p><b>CONCLUSION</b>The activity of T4 5'-deiodinase in iodine deficiency heightens and that in iodine excess is debased, the activity of T4 5-deiodinase in iodine deficiency and in iodine excess is debased.</p>

Effects of different levels of iodine nutrition on liver typeⅠdeiodinase and brain typeⅡdeiodinase activities in rat / 中华内分泌代谢杂志

Wistar rats with different levels of iodine nutrition were killed after 3,6 and 12 months of experiments.Serum thyroid hormones were assayed with RIA.The activity of typeⅠdeiodinase(DⅠ)and typeⅡdeiodinase(DⅡ)was measured based on the release of radioiodide from the ~(125)Ⅰ-labeled substrate.The result showed that hypothyroidism reflected by decreased T_4 happened during the initial phase of iodine deficiency.The activity of DⅠand DⅡin rats was raised significantly in iodine deficiency groups.An excess of iodine inhibited DⅠactivity resulting in decreased serum TT_3 and FT_3.However,DⅡactivity increased in rats with iodine excess, attributing to the inactivation of T_3 and T_4 to the substrate of DⅡenzyme.