Chinese herbs for shen invigorating and blood activating activated MMP-9 signaling pathway to mobilize rats' bone marrow EPCs: a molecular mechanism research / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the effect of Chinese herbs for Shen invigorating and blood activating (CHSIBA) on the number of endothelial progenitor cells (EPCs) in the bone marrow and the peripheral blood and the signaling pathway of bone marrow matrix metalloproteinase 9 (MMP-9) of the myocardial infarction (MI) model rats.</p><p><b>METHODS</b>The MI rat model was established by ligation. Thirty successfully modeled rats were randomly divided into the high dose CHSIBA group, the low dose CHSIBA group, and the model group, 10 in each group. Besides, another 10 normal rats were recruited as the blank group. Rats in the high dose CHSIBA group and the low dose CHSIBA group were administered with CHSIBA at 3 g/kg and 1.5 g/kg body weight by gastrogavage (by adding them in 4 mL physiological saline), once daily. Rats in the model group and the blank group were administered with 4 mL physiological saline once daily. The EPCs were collected from the bone marrow and the peripheral blood 4 weeks later. Seven days later the CD34/CD133 phenotype was identified in collected sticking wall cells using flow cytometry. The MMP-9 and water soluble Kit ligand (sKitL) were detected using Western blot. The expressions of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1alpha (SDF-1alpha) were detected using ELISA.</p><p><b>RESULTS</b>The CD34/CD133 positive rate and the EPC quantity in the bone marrow and the peripheral blood were higher in the high dose CHSIBA group and the low dose CHSIBA group than in the model group (P < 0.05, P < 0.01). Besides, the expressions of VEGF, SDF-1alpha, MMP-9, and sKitL in the bone marrow and the peripheral blood were also higher in the high dose CHSIBA group and the low dose CHSIBA group than in the model group (P < 0.05, P < 0.01).</p><p><b>CONCLUSION</b>CHSIBA could activate MMP-9 signaling pathway, increase its upstream and downstream signal expression levels, and mobilize EPCs in the bone marrow to enter the blood circulation.</p>

Study on effect of backrest thickness to lumbar muscle fatigue during computer work / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between backrest thickness and lumbar muscle fatigue so as to confirm the fitting backrest thickness.</p><p><b>METHOD</b>Twenty subjects coming from university seated at a computer workstation in three backrest thicknesses: 4, 7 and 10 cm. The time that the subjects reported the lumbar muscle fatigue was collected during each trial and subjective appraise was collected at the end of the entire protocol.</p><p><b>RESULTS</b>The MF value decreased and lumbar muscle felt fatigue in all three backrest thickness. Subject could feel fatigue more late [(45.0 +/- 10.8) min] and subject felt more comfort at 7 cm thickness.</p><p><b>CONCLUSION</b>It is better to relive computer worker lumbar muscle fatigue when the backrest thickness was kept on 7 cm. Work break was needed because one hour work could cause muscle fatigue.</p>