ABSTRACT
Amniotic fluid embolism is a rare but extremely dangerous complication in pregnant women.Its pathogenic pathophysiological nature is an immune process of the mother.This cascade endogenous immune response can quickly cause multiple organ dysfunction of the mother.Therefore,the treatment for this disease requires a multi-disciplinary and close collaborative medical rescue team in order to ensure the maternal and fetal safety in China.
ABSTRACT
Objective · To investigate the effect of Toll-like receptor 4 (TLR4) in the pathological injury in fat embolism mice model. Methods · One hundred and twenty male C57BL/6 mice were randomly divided into 10 groups. One group was set as blank control group, and others were injected separately with 1, 2…9 μL/g of allogeneic perirenal fat via tail vein, respectively. The mortality of each group was counted, median lethal dose (LD50) of fat injection in mice was calculated by Bliss method, and the fat embolism LD50 mice model was established. The TLR4 protein expression in the pulmonary tissue of surviving mice was detected by Western blotting. Sixty male C57BL/6 mice were randomly divided into the control group (the same dose of saline was given via tail vein) and the experimental groups (group 2 h, group 8 h, group 24 h and group 48 h, the LD50 fat was given via tail vein).The TLR4 protein expression at different time after fat injection was detected by Western blotting. The mortality of 20 TLR4 gene-knockout mice (TLR4-/-mice) was recorded and compared with 60 wild-type mice after LD50 fat injection. Results · The LD50 of fat embolism mice model was (3.93±0.78) μL/g.After the injection of 1-7 μL/g fat, the expressions of TLR4 protein in the pulmonary tissue of all seven groups were significantly increased, compared with the control group (all P=0.000). In the fat embolism LD50 mice model, compared with the control group, the expressions of TLR4 protein in group2 h were significantly increased (P=0.005). Then, expression level of TLR4 protein was gradually reduced after 2 h, and there was no significant difference between the control group and group 48 h. The mortality of TLR4-/- mice injected with LD50 fat was lower than that of wild-type mice (P=0.043).Conclusion · TLR4 protein involves in the pathologic process of fat embolism syndrome. The knockout of TLR4 gene can reduce the mortality of fat embolism mice. TLR4 and its correlated non-infectious inflammatory response may be an important molecular mechanism of biochemical injury in fat embolism syndrome. Blocking the activation of TLR4-mediated signaling pathway can significantly improve the prognosis, which provides new basis for the prevention, evaluation and treatment of fat embolism syndrome.
ABSTRACT
Objective To establish a method of isolation and purification of rat skeletal muscle satellite cells,and observe the characteristics of proliferation and myotube cell formation of skeletal muscle satellite cells cultured in vitro. MethodsPurified skeletal muscle satellite cells were obtained by improved two-step enzymatic digestion method and pre-plating technique.Immunohistochemical staining was employed to identify the skeletal muscle satellite cells cultured in vitro.The growth of skeletal muscle satellite cells cultured in vitro was examined by MTT assay.The differentiation of skeletal muscle satellite cells was observed by inverted microscopy. Results The skeletal muscle satellite cells with higher purity were obtained and confirmed by the high expression of desmin.When cultured in vitro,the latent phase of skeletal muscle satellite cells was the first to the second day,and the platform phase was the fifth to the sixth day.Myotube cells gradually formed when cell confluence was more than 60% to 70% or differential medium with lower fetal bovine serum was used.Conclusion The combination of improved two-step enzymatic digestion method and pre-plating technique serve as an easy and practical way to obtain skeletal muscle satellite cells with higher purity.Skeletal muscle satellite cells can form myotube cells with contraction characteristics without any special induction.