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Objective:To investigate the mechanism of crush syndrome (CS) induced by crush injury on myocardial cells in rats.Methods:Thirty two male Sprague Dawley (SD) rats were randomly divided into control group, CS-0 group, CS-12 group and CS-24 group with 8 rats in each group. CS model was made by self-made extruder and perfused with 4% paraformaldehyde for 0, 12 and 24 h. The morphological changes of myocardial tissue were observed by hematoxylin staining. The apoptosis of cardiomyocytes was detected by terminal dexynucleotide transferase-mediated nick end labeling (TUNEL). The levels and activities of malondialdehyde (MDA), superoxide dismutase (SOD), lactose dehydrogenase (LDH), interleukin-6 (IL-6), interleukin-1 β (IL-1 β), tumor necrosis factor-α (TNF- α) in myocardial homogenate were detected by enzyme-linked immunosorbent assay (ELISA). The expressions of Caspase-3, Bax, Bcl-2 and necrosis factor-κB (NF-κ B) were detected by Western blot.Results:Compared with the control group, the myocardial tissue of CS model group had different degrees of morphological damage; compared with the control group, the apoptosis rate, Caspase-3 and Bax protein expression levels of CS-0 group, CS-12 group and CS-24 group were significantly increased ( P<0.05), and the expression level of Bcl-2 protein was significantly decreased ( P<0.05); compared with the control group, the levels of MDA, LDH, IL-6, IL-1β, TNF-α and p65 protein phosphorylation in the myocardial homogenate of CS-0 group, CS-12 group and CS-24 group were significantly increased ( P<0.05), and SOD activity was significantly decreased ( P<0.05). Conclusions:CS may inhibit oxidative stress and induce inflammatory reaction by activating NF-κ B pathway, thus damaging myocardial cells in rats.
RESUMO
Objective To observe bone formation of compound of autologous periosteum cells plus calcium alginate gelatin in animal body and investigate the best mixing ratio of the two components.Methods A total of 96 healthy adult New Zealand rabbits were randomly divided into six groups (Groups A,B,C,D,E and control group).The excised bilateral periostea from rabbits in each experimental group were all made into 0.4 ml cell suspensions.The compounds were prepared by blending 0.4 ml calcium alginate gelatin with 1,1/4,1/16,1/64 and 1/256 of the periosteum cell suspension respectively,and then were applied to autologous right radial defect area.Gross observation,X-ray examination and histological study were carried out at 2,4,8,12 weeks postoperatively.Levels of serum alkaline phosphatase and serum calcium were determined as well.Results The compounds containing periosteum cell suspension with cell counts of 1/4 or 1/16 and calcium alginate gelatin reached the best osteogenesis.Conclusion Compound of autologous periosteum cell suspension-calcium alginate gelatin induces obvious bone formation and is worthy of clinical application,for it has advantages of satisfactory bone defect repair and easy operation.