Effects of Hip Abductor Fatigue on Neuromuscular Control During Single-Leg Side-Jump Landing in Different Gender Groups / 医用生物力学

Objective To compare the effects of hip abductor fatigue on postural stability and neuromuscular control in different gender groups during single-leg side-jump landing. Methods Twenty male and twenty female adults were required to execute single-leg side-jump landing before and after hip abductor fatigue protocol. The center of pressure (COP), ground reaction force (GRF), lower extremity kinematics, joint moment, muscle activity were compared. Results For both males and females after fatigue, the maximum displacements and average velocities of COP decreased, and the peak angles of hip abduction and ankle eversion increased, and the peak torques of ankle inversion increased. At 200 ms pre-landing, the activiation of rectus femoris, biceps femoris, tibialis anterior, peroneus longus were lower in male than that in female. At 200 ms post-landing, the activiation of biceps femoris in male was lower than that in female after fatigue. Conclusions The postural stability in frontal plane decreased after hip abductor fatigue. The frontal plane control of hip joint and ankle joint was weakened, which might increase the risk of joint injury. There are differences in postural strategies for different genders, indicating that gender difference in the mechanism of lower limb joint injury is worth of further investigation.

Effect of hypotension factor on endotracheal tube cuff-induced damage to tracheal mucous mem-brane of rabbits / 中华麻醉学杂志

Objective To evaluate the effect of hypotension factor on endotracheal tube cuff-in-duced damage to tracheal mucous membrane of rabbits. Methods Eighty healthy rabbits of both sexes, aged 3.0-3.5 months, weighing 2.5-3.5 kg, were divided into 16 groups(n=5 each)according to the cuff pressure and mean arterial pressure(MAP): different cuff pressures when MAP did not decrease groups(C1M1group, C2M1group, C3M1group, C4M1group), different cuff pressures when MAP de-creased by 20% of the baseline value groups(C1M2group, C2M2group, C3M2group, C4M2group), dif-ferent cuff pressures when MAP decreased by 30% of the baseline value groups(C1M3group, C2M3group, C3M3group, C4M3group), and different cuff pressures when MAP decreased by 40% of the baseline value groups(C1M4group, C2M4group, C3M4group, C4M4group). Different cuff pressures were 0, 10, 20 and 30 cmH2O.At 2 h of tracheal intubation, the tracheas in the cuff-compressed area were harvested and sliced for examination of the pathological changes of tracheal mucous membrane after haematoxylin and eosin staining(with a light microscope), and the damage to tracheal mucous membrane was scored. Results When at the same low pressure(MAP decreased by 20%, 30% and 40% of the baseline value), the score of damage to tracheal mucous membrane increased with the increasing cuff pressures(P<0.05). When at the same cuff pressure(10, 20 and 30 cmH2O), the score of damage to tracheal mucous membrane in-creased with the increasing MAP(P<0.05). There was interaction between cuff pressure and MAP, F=2.034(P<0.05). Conclusion There is interaction between the effects of hypotension factor and endotra-cheal tube cuff factor on damage to tracheal mucous membrane; hypotension factor can aggravate endotra-cheal tube cuff-induced damage to tracheal mucous membrane of rabbits.

Lipid synthesis by an acidic acid tolerant Rhodotorula glutinis / 生物工程学报

Acetic acid, as a main by-product generated in the pretreatment process of lignocellulose hydrolysis, significantly affects cell growth and lipid synthesis of oleaginous microorganisms. Therefore, we studied the tolerance of Rhodotorula glutinis to acetic acid and its lipid synthesis from substrate containing acetic acid. In the mixed sugar medium containing 6 g/L glucose and 44 g/L xylose, and supplemented with acetic acid, the cell growth was not:inhibited when the acetic acid concentration was below 10 g/L. Compared with the control, the biomass, lipid concentration and lipid content of R. glutinis increased 21.5%, 171% and 122% respectively when acetic acid concentration was 10 g/L. Furthermore, R. glutinis could accumulate lipid with acetate as the sole carbon source. Lipid concentration and lipid yield reached 3.20 g/L and 13% respectively with the initial acetic acid concentration of 25 g/L. The lipid composition was analyzed by gas chromatograph. The main composition of lipid produced with acetic acid was palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, including 40.9% saturated fatty acids and 59.1% unsaturated fatty acids. The lipid composition was similar to that of plant oil, indicating that lipid from oleaginous yeast R. glutinis had potential as the feedstock of biodiesel production. These results demonstrated that a certain concentration of acetic acid need not to be removed in the detoxification process when using lignocelluloses hydrolysate to produce microbial lipid by R. glutinis.

miR-218 expression in osteosarcoma tissues and its effect on cell growth in osteosarcoma cells

OBJECTIVE@#To investigate the expression of miR-218 and its clinical significance in osteosarcoma tissues and explore its effect on proliferation and apoptosis in osteosarcoma cells.@*METHODS@#miR-218 expression was detected in 76 samples of surgically resected osteosarcoma and matched normal tumor-adjacent tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR). MiR-218 was over-expressed by exogenous miR-218 plasmids in Saos-2 cells, and then BrdU cell proliferation assay and flow cytometry were used to determine cell proliferation and apoptosis.@*RESULTS@#The expression of miR-218 in osteosarcoma tissues was significantly lower than those in normal tumor-adjacent tissues (t=8.735, P<0.001). MiR-218 expression in tumor tissues was significantly correlated with tumor size (χ(2)=5.380, P=0.020), clinical stage (χ(2)=6.692, P=0.010) and distant metastasis (χ(2)=4.180, P=0.041). MiR-218 was obviously over-expressed by exogenous miR-218 plasmids (t=19.42, P<0.001), and miR-218 overexpression significantly reduced cell proliferation (t=9.045, P<0.001) and induced apoptosis (t=12.38, P<0.001) in Saos-2 cells.@*CONCLUSIONS@#The low-expression of miR-218 is correlated with the poor clinicopathological features in osteosarcoma. Moreover, miR-218 overexpression reduces cancer cell proliferation and induces apoptosis in Saos-2 cells, suggesting that miR-218 may play a key role in the progression of human osteosarcoma.

miR-218 expression in osteosarcoma tissues and its effect on cell growth in osteosarcoma cells

Objective: To investigate the expression of miR-218 and its clinical significance in osteosarcoma tissues and explore its effect on proliferation and apoptosis in osteosarcoma cells. Methods: miR-218 expression was detected in 76 samples of surgically resected osteosarcoma and matched normal tumor-adjacent tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR). MiR-218 was over-expressed by exogenous miR-218 plasmids in Saos-2 cells, and then BrdU cell proliferation assay and flow cytometry were used to determine cell proliferation and apoptosis. Results: The expression of miR-218 in osteosarcoma tissues was significantly lower than those in normal tumor-adjacent tissues (t=8.735, P<0.001). MiR-218 expression in tumor tissues was significantly correlated with tumor size (χ