The effect of ischemic precondition to IL-6 on rat liver ischemiareperfusion injury in transplantation

Objective:To investigate the effect of ischemic precondition to protect ischemia-reperfusion injury and reduce IL-6 expression in the rats liver transplantation.Methods:The rat portal vein infusion of autologous liver transplantation model were used.The rats were divided into ischemic preconditioning rats liver transplantation group(A group),the rats liver transplantation group(B group) and the normal rat control group(C group).Then we analyzed the changes of liver function,liver microstructure and the expression of IL-6,SOD and MDA within 48 h.Results: The pathology of liver in group A showed lobular architecture essentially normal,the liver cells was slightly swell and no significant changes in postoperative 12 h.In transmission electron microscope(46 000X).the mitochondria of liver cells in group A i】ecame swelling,elliptical can cristae partially broken.But there still has a small amount of arrangement.While that in group, the mitochondria were swollen,became round,serious visible crest reduce or ruptured.The result of over function test showed that the serum ALT and AST levels in group A and B were both higher than that in group C at each time period,but the serum ALT and AST levels in group A were lower than that in group B.The expression changes of IL-6 in group B were higher than that in group A and R(P【0.05).The expression of MDA in group A is more obvious than that in group B(P【0.05).Conclusions:Ischemic precondition could alleviate part of ischemia-reperfusion injury in the rat liver transplantation,and also could reduce IL-6 expression to protect the liver cells against liver damage and inflammatory cytokine production.

Role of cathepsin B-mediated apoptosis in fulminant hepatic failure in mice

AIM: To investigate the pathogenic role of cathepsin B and the protective effect of a cathepsin B inhibitor (CA074Me) in fulminant hepatic failure in mice. METHODS: LPS/D-Gal N was injected into mice of the model group to induce fulminant hepatic failure; the protected group was administered CA-074me for 30 min before LPS/D-Gal N treatment; the normal group was given isochoric physiologic saline. Liver tissue histopathology was determined with HE at 2, 4, 6 and 8 h after Lps/D-Gal injection. Hepatocyte apoptosis was examined by TUNEL method. The expression of cathepsin B in liver tissues was investigated by immunohistochemistry, Western blot and RT-PCR. RESULTS: Compared with the normal group, massive typical hepatocyte apoptosis occurred in the model group; the number of apoptotic cells reached a maximum 6 h after injection. The apoptosis index (AI) in the protected group was clearly reduced (30.4 ± 2.8 vs 18.1 ± 2.0, P < 0.01 ). Cathepsin B activity was markedly increased in drug-treated mice compared with the normal group (P < 0.01). Incubation with LPS/D-Gal N at selected time points resulted in a timedependent increase in cathepsin B activity, and reached a maximum by 8 h. The expression of cathepsin B was significantly decreased in the protected group (P < 0.01). CONCLUSION: Cathepsin B plays an essential role in the pathogenesis of fulminant hepatic failure, and the cathepsin B inhibitor CA-074me can attenuate apoptosis and liver injury.

Hepatoprotective effects of cathepsin B inhibitor on acute hepatic failure induced by lipopolysaccharide/D-galactosamine in mice

BACKGROUND:Increasing evidence suggests that the inactivation of cathepsin B attenuates hepatocyte apoptosis and liver damage.This study aimed to investigate the protective effects of a cathepsin B inhibitor(CA-074me) on lipopolysaccharide(LPS)/D-galactosamine(D-GalN)-induced acute hepatic failure(AHF) in mice.METHODS:Mice were intraperitoneally injected with a combination of LPS/D-GalN to induce AHF with or without CA-074me pretreatment.The cumulative survival rates were calculated 48 hours after the induction of AHF.As well as changes in biochemical indicators and liver histology,hepatocyte apoptosis was assessed using a TUNEL method.Serum tumor necrosis factor-α(TNF-α) production,caspase-3,caspase-8,and caspase-9 activity was evaluated.Cytosolic cytochrome c and Bcl-2 expression were measured by Western blotting.RESULTS:The marked elevation in serum aminotransferase activity and prothrombin time found in LPS/D-GalN-treated mice was significantly improved by pretreatment with CA074me.The efficacy of CA-074me was also confirmed by histological analysis and TUNEL assay.The survival rate significantly improved in LPS/D-GalN-induced mice given CA-074me compared with untreated mice.LPS/D-GalNinduced caspase-3 and caspase-9 activation was remarkably suppressed by CA-074me.However,the increased levels of serum TNF-α and elevated caspase-8 activity in AHF mice were not significantly reduced by CA-074me.Moreover,CA074me sharply reduced the increased expression of cytosolic cytochrome c and markedly augmented Bcl-2 expression.CONCLUSION:These results suggest that CA-074me has a protective effect in acute hepatic failure induced by LPS/D-GalN.

Inhibition of tumor angiogenesis by TTF1 from extract of herbal medicine

AIM:To study the inhibition of tumor angiogenesis by 5,2,4'-trihydroxy-6,7,5'-trimethoxyflavone(TTF1) isolated from an extract of herbal medicine Sorbaria sorbifolia.METHODS:Angiogenic activity was assayed using the chick embryo chorioallantoic membrane(CAM) method.Microvessel density(MVD) was determined by staining tissue sections immunohistochemically for CD34 using the Weidner capillary counting method.The mRNA and protein levels of vascular endothelial growth factor(VEGF),vascular endothelialgrowth factor receptor 2(VEGFR2,Flk-1/KDR),basic fibroblast growth factor(bFGF),cyclo-oxygenase(COX)-2 and hypoxia-inducible factor(HIF)-1α were detected by quantitative real-time polymerase chain reaction and Western blotting analysis.RESULTS:The TTF1 inhibition rates for CAM were 30.8%,38.2% and 47.5% with treatment concentrations of 25,50 and 100 μg/embryo × 5 d,respectively.The inhibitory rates for tumor size were 43.8%,49.4% and 59.6% at TTF1 treatment concentrations of 5,10,and 20 μmol/kg,respectively.The average MVD was 14.2,11.2 and 8.5 at treatment concentrations of 5 μmol/kg,10 μmol/kg and 20 μmol/kg TTF1,respectively.The mRNA and protein levels of VEGF,KDR,bFGF,COX-2 and HIF-1α in mice treated with TTF1 were significantly decreased.CONCLUSION:TTF1 can inhibit tumor angiogenesis,and the mechanism may be associated with the down-regulation of VEGF,KDR,bFGF,HIF-1α and COX-2.

H_∞ controller design for a 4-meter direct-drive azimuth axis

To pursue a higher imaging resolution for exploring more details in the information conveyed by the Universe, the next generation of optical telescopes based on a direct drive widely employ the extremely large aperture structure, which also introduces more disturbances and uncertain factors to the control system. Facing this new challenge, the PID control method in main-axis control systems of traditional astronomical telescopes cannot suffice for the requirement of the tracking precision and disturbance sensitivity in angular velocity. To overcome this shortcoming, we establish a dynamic model and propose an H∞ controller for a 4-meter azimuth direct drive control system that consists of a revolving platform（azimuth axis）, a three-phase torque motor, a motor drive, an encoder, a data acquisition card and a small computers. Simulations are carried out to analyze the model and guide the real experiments.Experimental results show that the proposed H∞ controller reduces the tracking error by a maximum of 80.69%（average 57.8%） and the disturbance sensitivity by a maximum of 82.3%（average 50.96%） compared with the traditional tuned PI controller;furthermore, the order of the model describing the proposed controller can be reduced to three, thus its feasibility in real systems is guaranteed.

Generalized Latin Matrix and Construction of Orthogonal Arrays

In this paper, generalized Latin matrix and orthogonal generalized Latin matrices are proposed. By using the property of orthogonal array, some methods for checking orthogonal generalized Latin matrices are presented. We study the relation between orthogonal array and orthogonal generalized Latin matrices and obtain some useful theorems for their construction. An example is given to illustrate applications of main theorems and a new class of mixed orthogonal arrays are obtained.