BACKGROUND:Studies have shown that Schwann cells form a Bunger band in the basement tube and guide the extension of regenerating axons after peripheral nerve injury, but the exact mechanism remains to be explored.
OBJECTIVE:To explore the effect of Wal erian degeneration on biological characteristics and secretory function of Schwann cells in rats with sciatic nerve injury.
METHODS:A rat model of sciatic nerve injury was established and divided into two groups:sciatic nerve transection group and surgical control group. Schwann cells were isolated and cultured from sciatic nerve segments by one enzyme digestion. The cellmorphology was observed under light microscope and S-100 protein expression was determined by immunofluorescence staining. After subculture, the first generation of Schwann cells were chosen to draw the growth curve by the counting method within 14 days. The cellactivity was detected by MTT assay. The adhesion of Schwann cells was examined by acid phosphatase analysis and the concentration of nerve growth factor was detected by ELISA method.
RESULTS AND CONCLUSION:At 14 days after primary culture, a great number of Schwann cells were observed near the edges of nerve segments in the sciatic nerve transection group, but only smal number of Schwann cells scattered around nerve segments in the control group. Schwann cells in both groups showed S-100 positive expression. At 3 days after subculture, Schwann cells reached the logarithm proliferative phase, the cellnumber and proliferation absorbance values in both groups were increased along with time extension. Furthermore, the number of Schwann cells and absorbance value in the sciatic nerve transection group were significantly higher than those of control group (P<0.05). The adhesion ability in the sciatic nerve transection group was also significantly higher than those in the control group (P<0.05). ELISA results showed that, the concentrations of nerve growth factor in the sciatic nerve transection group were significantly higher than those in the control group at 4, 6, 8, 10, 12 and 14 days (P<0.05). After sciatic nerve injury, Wal erian degeneration can induce Schwann cells dedifferentiate into the precursors, significantly influence the biological function of Schwann cells, promote the proliferation of Schwann cells within the short term, secrete large amounts of neurotrophic factors, enhance celladhesion, and provide a suitable microenvironment for regenerated axons. In addition, it creates the necessary microenvironment for peripheral nerve regeneration.

According to ISO 10993 standard series, the biological safety of surface modified pure titanium was studied as a percutaneous device by the test of cytotoxicity in vitro, as well as by the tests of irritation and sensitization. The result from the examination of cytotoxicity in vitro was negative, the skin irritation response was negligible, and the result of test on skin sensitization in guinea pigs was also negligible. So the surface modified pure titanium in this study can be safely used as percutaneous implanting materials.
Animals ; Biocompatible Materials ; chemistry ; Coated Materials, Biocompatible ; chemistry ; Female ; Guinea Pigs ; Implants, Experimental ; adverse effects ; Materials Testing ; Rabbits ; Random Allocation ; Skin Irritancy Tests ; methods ; Surface Properties ; Titanium ; chemistry

Objective To explore the influence of Yoga exercise on the work stress and coping styles of operating room nurses. Methods A total of 77 nurses were selected working in the operating room of our hospital,and all the nurses were randomly divided into observation group(38 cases)and the control group (39 cases). The nurses of observation group did Yoga exercise regularly,while the nurses of control group did not make any Yoga workout regularly. We used psychological stress scale( CPSS)to assess anxiety of two groups nurses before and after the intervention,and investigated every nurse's pressure coping style respectively before and after care. Results Pressure improvement mark in the observation group had been greatly improved after Yoga exercise intervention(16. 203 ± 4. 218),while it was(3. 127 ± 1. 037)in the control group with statistical significance( t = 3. 012,P < 0. 05);the improvement of anxiety in the observation group was significantly better than that of the control groups,the difference had statistical significance(P < 0. 05);the stress coping style of observation group were obvious improved after the intervention compared with that of the control group(P < 0. 05). Conclusions Yoga exercises can improve the working stress and coping operating room nurses effectively.