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BACKGROUND:Our previous studies confirmed that NGF-PEG-PLGA-NPs has good sustained release effect and biological activity in vitro, and can induce the differentiation of PC12 cel s into neuron-like cel s. OBJECTIVE:To investigate the feasibility of neuronal differentiation of neural stem cel s from septal area of fetal brain induced by NGF-PEG-PLGA-NPs and its influence on PI3K/Akt signaling pathway. METHODS:According to optimization prescription, NGF-PEG-PLGA-NPs were prepared by multiple emulsion solvent diffusion method. Neural stem cel s were induced to neuronal differentiation in six groups, including control group, NGF group, NGF-PEG-PLGA-NPs group, LY294002 group, LY294002+NGF group and LY294002+NGF-PEG-PLGA-NPs group. Neurons were identified by immunofluorescence, while phosphorylation levels of Akt in PI3K/Akt signaling pathway were detected by western blotting. RESULTS AND CONCLUSION:The proportions ofβ-Tubulin III-positive neurons in control group, NGF group, NGF-PEG-PLGA-NPs group, LY294002 group, LY294002+NGF group and LY294002+NGF-PEG-PLGA-NPs group were (22.80±2.58)%, (35.80±3.98)%, (35.40±5.77)%, (26.60±3.87)%, (21.20±2.59)%and (25.80±7.22)%, respectively. There were no statistical differences in neuronal differentiation between NGF group and NGF-PEG-PLGA-NPs group (P>0.05), but the ratios of neural differentiation in the two groups were both higher than that in the other four groups (P0.05), but the phosphorylation levels of Akt were both higher than other four groups (P0.05), but the phosphorylation levels of Akt were higher than LY294002 group (P<0.05). Results suggest that NGF-PEG-PLGA-NPs promoted neural differentiation of neural stem cel s. The role might be related to increasing phosphorylation levels of Akt in PI3K/Akt signaling pathway.
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The circle of Willis is the major cerebral collateral circulation.Its anatomical variation is in populations higher.The previous studies showed that anatomical variation in circle of Willis was an independent risk factor for cerebral ischemia.This article reviews the relationship between the various anatomical variation types of the circle of Willis and cerebral ischemia.
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Objective To investigate the protective effect of polymyxin B (PMB) to the liver graft after liver transplantation and the underlying mechanism in rats.Methods Male SD rats were selected as the donors and recipients.Non-artery whole liver transplantation model was established in rats according to Kamada's two-cuff method.The rats were divided into two groups by the way of random number table method:control group (normal saline,0.5 ml) and PMB group (PMB,1 mg/ml,0.4 mg/kg+ normal saline 0.5 ml).The levels of portal vein plasma endtotoxin (EU/ml)were determined by endotoxin-analyzing machine of BET-24A. ALT,BUN,and TNF-α,IL-6 in serum were measured by using machine of Automatic Analyzer and ELISA,respectively.The CD14,TLR4,NFκB and AP-1 in the grafts were measured by RT-PCR and Western blotting,and pathological changes were observed. Results PMB decreased the levels of portal vein plasma endotoxin 1 h after reperfusion in PMB group as compared with control group (P＜0.05),and the levels of portal vein plasma endotoxin returned to the normal levels 6 h after reperfusion in both two groups (P＞0.05).After operation,the levels of ALT,TNFα and IL-6 in serum were significantly reduced (P＜0.05),the expression of CD14 and TLR4 mRNA in the grafts was significantly decreased (P＜0.05),the expression of Hsp60 protein and mRNA,and NF-κB and AP1 proteins in the grafts were reduced (P＜0.05),and the pathological damage to the grafts was significantly alleviated in PMB group as compared with control group.Conclusion PMB reduced the levels of portal vein plasma endotoxin after reperfusion in liver transplantation in rats.PMB improved liver function,reduced the injury of inflammatory response,decreased the levels of endotoxin signal pathway markers and alleviated the pathological damage to the grafts.
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Objective To study the relationship between hepatic arterial buffer response (HABR),recovery of liver function,early biliary complications and small-for-size syndrome (SFSS).Methods Early hepatic hemodynamic parameters (including hepatic arterial flow (HAF),portal venous flow (PVF) were measured using duplex Doppler sonography in 34 patients who received living donor liver transplantation (preoperatively n＝26,intraoperatively n=26) and on postoperative days 1,2,3,and 7.Alanine aminotransferase (ALT),aspartate aminotransferase (AST) and total bilirubin (TBIL) level were measured preoperatively and on postoperative days 1,2,3,7,14,21,and 28.If TBIL level was elevated,we used B ultrasonography or CT and even ERCP to diagnose early biliary complications.The days taken for AST,AI T and TBIL to recover and the number of patients with early (＜60 days) biliary complications (bile leakage or bile stricture) and with small-for-size syndrome (SFSS) were recorded.Results Passive hepatic artery buffer response (HABR) was present in 11 patients early after living donor liver transplantation (group 1) and it disappeared in 23 patients (group 2).The recovery in days taken for normalization of AST (10.6± 8.8),AIT (11.6±9.0) and TBlL (average of 29) in group 1 were shorter than in group 2.However,the differences did not reach statistics difference (P＞0.05).The overall incidences of early biliary complications and small-for-size syndrome (SFSS) in group 1 were significantly lower than in group 2 (P=0.04).The survival rate in group 1 was 82 ％,compared with 74 ％ in group 2.Conclusions Passive hepatic arterial buffer response (HABR) disappeared in some patients early after living donor liver transplantation.There were high incidences of early biliary complications and small-for-size syndrome (SFSS) in these patients.Measurcment of hepatic buffer response in the early stage after living donor liver tranaplanta tion is valuable for predition of early biliary complications and small-for-size syndrome (SFSS),thus helping to prevent failure in transplantation.
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Objective To investigate and compare the dynamic changes of plasma endotoxin and CD14/TLR4 levels in the portal vein following partial liver transplantation in rats. Methods 100 %(group Ⅰ), 50 % (group Ⅱ) and 30 % (group Ⅲ) orthotopic liver transplantation models in the SD rats→SD rats were established in vivo according to "Kamada two-cuff method". Based on the principle of dynamic turbidity law, the plasma endotoxin (EU/ml) levels were determined at the postoperative time points of 1, 3, 6, 12, 24 h in recipients. The mRNA expression levels of CD14 and TLR4 in liver grafts were detected by using real-time RT-PCR. Results Under the condition of no significant difference in surgical factors, the plasma endotoxin levels in the portal vein of groups Ⅱ and Ⅲ were higher than in group Ⅰ , and reached the peak at the first h postoperation. The endotoxin levels in group Ⅱ were lower than in group Ⅲ. The endotoxin levels in sham-operation group were the highest. The mRNA expression levels of CD14 and TLR4 in groups Ⅰ, Ⅱ and Ⅲ were significantly increased as compared with sham-operation group (P＜0. 01). Conclusion There exists portal vein plasma endotoxima in 100 %, 50 % and 30 % orthotopic liver transplantation in the rats. The smaller the graft volume, the higher and longer plasma endotoxin in portal vein, so is the relative quantification of the TLR4 and CD14 mRNA in liver grafts.