Animals ; Heart Ventricles ; cytology ; Lipid Bilayers ; Potassium Channels ; Sarcolemma ; physiology ; Swine

BACKGROUND: The degree of neurofilament (NF) phosphorylation is closely correlated with the occurrence of Alzheimer disease (AD), and apolipoprotein E4 (apoE4) is a generally acknowledged liability factor for AD, but the effect and mechanism of apoE4 on the NF phosphorylation in neurons are not very clear. It has been reported that in the neurons cultured in vitro and in brain tissue of AD patients, the amino acid residues of apoE4 protein C terminal (272-299) could be truncated by hydrolysis,and produce truncated-apoE4 fragment. The latter interacts with the NF phosphorylation in neurofibrillary tangles (NFTs), which are the characteristic pathological changes of AD.OBJECTIVE: To observe the effect of truncated-apoE4 overexpression on the NF phosphorylation in the cultured neurons.DESIGN: A non-randomized controlled observation.SETTING: Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology.MATERIALS: The experiment was carried out in the Laboratory of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology in December 2005. The mice neuroma cell strain N2a was provided by Dr. Xu.METHODS: The truncated-apoE4(△272-299) cDNA was subcloned into pEGFP-c3 to form pEGFP-T-apoE4 recombinant. Then pEGFP-c3, pEGFP-apoE4 and pEGFP-T-apoE4 were transfected into N2a cells by lipofectamine2000 respectively. NF phosphorylation was detected by Western blot assay. The activities of glycogen synthase kinase-3 (GSK-3) and cyclin-dependent kinase 5(CDK-5) were measured.MAIN OUTCOME MEASURES: The degree of NF phosphorylation and the activities of GSK-3 and CDK-5 were mainly observed.RESULTS: In the transfected groups, the contents of phosphorylated NF were significantly increased, the GSK-3 activities were significantly increased, which were the most significant in the pEGFP-T-apoE4 transfected group (P＜0.05), but the CDK-5 activities were not significantly different from that in th e control group (P＞0.05).CONCLUSION: These results indicate that in vitro overexpression of truncated-apoE4(△272-299) can lead to NF hyperphosphorylation by activating of GSK-3 but not CDK-5, which may be the underline mechanism of AD induced by truncated-apoE4(△272-299).

Objective To investigate the influences of mutation at precore and basic core promoter(BCP) region in hepatitis B virus(HBV) on the immune response of specific cytotoxic T lymphocytes(CTL) in patients with chronic hepatitis B(CHB).Methods The number of specific CTL in peripheral blood mononuclear(PBMC) of CHB patients were tested by cytokine flow cytome- try(CFC) and HBV core18-27 peptide.HBV precore and BCP fragments were directly sequenced. Results Twenty-one(38.9%) samples were HBV precore G1896A mutation.Twenty-six(48.1%) samples were BCP region 1762/1764 combined mutation.Thirteen(24.1%) stains were three sites mutated simultaneously.Stimulated with HBV core 18-27 in vitro,the specific CTL level was signifi- cantly higher in the patients with G1896A mutation and BCP region mutation [(0.41?0.09)%, (0.36?0.08)%,(0.48?0.08)%,respectively]than those without mutation[(0.11?0.06)%, P

Cathepsin B from Helicoverpa armigera (HCB) belongs to the group of cysteine proteinases. HCB is proved being involved in the degradation of yolk proteins during embryonic development,which is an acidic preferring enzyme and is resistant to SDS. The expression of the proenzyme may offer a model for investigating the activation of the enzyme. The HCB gene was constructed into pPIC9K and expressed in Pichia pastoris KM71 strain . After induction by methanol, HCB was expressed and secreted into the medium. The molecular weight of the recombinant procathepsin B was determined as about 38 kDa. The expressed product was confirmed to be HCB by immunoblotting assay using specific rabbit anti-HCB polyclonal antibody. The activity of the product was assayed by in situ hydrolysis (gelatin-SDS-PAGE). These results showed that HCB with proteolytic activity was expressed in P. pastoris KM71. This proenzyme can be used for further research on the activation of the proenzyme or industrial production.

Animals ; Bone Morphogenetic Protein 2 ; metabolism ; Bone Morphogenetic Protein 4 ; metabolism ; Carrier Proteins ; pharmacology ; Liver ; metabolism ; Liver Regeneration ; Male ; Rats ; Rats, Wistar

Objective To determine the impact of fluorine and aluminum,and both action combined on the number of rat osteoclasts and bone resorption cultured in vitro and to explore its mechanisms.Methods The osteoclasts and bone marrow stromal cells (BMSCs) isolated from long bone of new born rats were cultured,respectively,in TC199 medium (containing 10％ fetal bovine serum) with fluoride,aluminum and fluoride combined with aluminum.The osteoclasts were inoculated in 96-well culture plate and ivory slice,BMSCs in 6-well culture plate,and culture medium was changed after 2 hours incubation.The cells were divided into control group,fluoride group,aluminum group and fluoride combined with aluminum group; the doses of sodium fluoride were 0,1.0 × 10-4,0,1.0 × 10-4 mol/L and the doses of aluminum chloride were 0,0,1.0 × 10-5,1.0 × 10-5 mol/L,respectively.Tartrate-resistant acid phosphatase (TRAP) staining positive cells were counted under light microscope after TRAP staining on the 5th day and the pit formed in ivory slices were measured by histomorphometry after staining with toludine blue.The expression of osteoprotegerin(OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) was detected by real-time fluorescence quantitative PCR in BMSCs after 8 h treatment.Results ① Fluoride,aluminum and the interactive effects of fluoride and aluminum all had impact on the numbers of osteoclasts (F =7.15,6.56 and 7.98,respectively,all P ＜ 0.05).The numbers of osteoclasts in fluoride group,aluminum group and fluoride combined with aluminum group[(136.9 ± 22.99),(135.4 ± 23.5),(163.0 ± 24.4) per well] were higher than that in the control group[(92.5 ± 22.1) per well,all P ＜ 0.05].② Fluoride,aluminum and the interactive effects of fluoride and aluminum all had impact on the resorption pit area on ivory slices(F =10.47,12.64,14.29,respectively,all P ＜ 0.05).The resorption pit area on ivory slices in fluoride group,aluminum group and fluoride combined with aluminum group[(0.242 ± 0.031),(0.293 ± 0.026),(0.333 ± 0.016)mm2 per slice] was higher than that in the control group [(0.088 ± 0.030)mm2 per slice,all P ＜ 0.05].③Fluoride,aluminum and the interactive effects of fluoride and aluminum all had impact on the expression ratios of RANKL/OPG in BMSCs (F =8.15,15.38,23.59,respectively,all P ＜ 0.05).The expression ratios of RANKL/OPG in BMSCs in fluoride group,aluminum group and fluoride combined with aluminum group [(193.98 ± 137.93)％,(326.11 ± 176.78)％,(599.84 ± 275.82)％] were higher than that in the control group[(100.00 ± 56.02)％,all P ＜ 0.05].Conclusions Both fluoride and aluminum can cause increase in the number of osteoclasts in vitro and promote cell differentiation and bone resorption activity,which may be related to increased expression ratio of RANKL/OPG mRNA in BMSCs.The stimulating effects of fluoride on osteoclasts differentiation and bone resorption is enhanced by aluminum.

Background Presbyopia is one of primary causes affecting the visual and life qualities of the agings,and its mechanism is associated with the oxidative damage of lens epithelial cells with ageing.SS31 is a mitochondria-targeted antioxidant peptide.To study the effect of SS31 on oxidative damage of lens epithelial cells has an important significance for the prevention and treatment of presbyopia.Objective This study was to investigate the effect of SS31 on in vitro oxidative damaged human lens epithelial cells.Methods Human lens epithelial cell line (HLEB-3) was cultured using DMEM with low glucose and 10％ fetal bovine serum(FBS).The cell model of oxidative damage was established by adding 200 μmol/L tea-butyl hydropeoxide (t-BHP) into DMEM for 18 hours.The cells were divided into blank control group,t-BHP model group,10 nmol/L SS31 +t-BHP group,100 nmol/L SS31 +t-BHP group,1 μmol/L SS31 +t-BHP group,10 μmol/L SS31 +t-BHP group and 100 pμmol/L t-BHP group,and then MTT assay was used to detect the survival rate of the cells and evaluate the optimal SS31 concentration for sequential study.The cells then were divided into blank control group,t-BHP model group and 1 μmol/L SS31 +t-BHP co-culture group.The change of mitochondrial membrane potential of the cells was tested by JC-1 dye and flow cytometry.Reactive oxygen species (ROS) level in the mitochondria was determined using MitoSOX staining.Results The cell survival rate in the t-BHP model group was (53.42±2.52)％,and that in the blank control group was 100％.The cell survival rate was considerably increased in various concentrations of SS31 groups,showing a significant difference among different groups (F=58.349,P＜0.01).A highest survival rate was (82.13 ±3.15) ％ in the 1 μmol/L SS31 +t-BHP co-culture group,which was statistically significant in comparison with the t-BHP model group (t =28.710,P＜0.05).JC-1 dye and flow cytometry assay showed that the ratio between red and green fluorescence intensity was 7.07 ±0.06 in the blank control group,4.46±0.14 in the t-BHP model group and 5.76±0.26 in the 1 μmol/L SS31 +tBHP co-culture group,showing significant difference among the 3 groups (F=172.332,P＜0.01).The ratios between red and green fluorescence intensity in the blank control group and 1 μmol/L SS31 +t-BHP co-culture group were higher than that in the t-BHP model (t =2.609,1.303,both at P＜0.001).ROS fluorescence cells were much more in the t-BHP model group compared with blank control group and 1 μmol/L SS31 + t-BHP co-culture group.Conclusions SS31 can protect HLEB-3 cells from oxidative stress.SS31 may serve as a potential new approach to the treatment of presbyopia and other age-related diseases of lens.

Cirrhosis with portal hypertension is a common disease which has a significant impact on the quality of patients' life. Esophagogastric devascularization (EGDV) has been demonstrated to be an effective method to treat portal hypertension, however certain complications are associated with it. The purpose of this study was to evaluate the effectiveness and clinical outcome of the selective EGDV (sEGDV) for the treatment of portal hypertension. The study was conducted prospectively from Jan. 1 2011 to Dec. 31, 2012, and 180 patients were randomized to the sEGDV group (n=90) or the non-sEGDV (n-sEGDV) group (n=90). Patients' demographics, preoperative lab test results and operative details were comparable between the two groups. Postoperative and short-term complications were analyzed in two groups. There was statistically significant difference (P<0.01) in the PVF reduction between the two groups. Post-operative complications showed no statistically significant difference between the two groups in the incidence of bleeding, ascites, acute portal vein thrombosis, fever and hepatic encephalopathy. Mortality between two groups was comparable. The incidence of splenic fossa effusion after the surgery was lower in sEGDV group than in n-sEGDV group. There were no significant differences in the short-term follow-up data such as esophageal varices and portal hypertensive gastropathy (P>0.05). It is suggested that sEGDV is a safe, simple and effective surgical procedure. It has both the advantages of the shunt and devascularization because it preserves body's voluntary diversion. With the advantage of low incidence of postoperative complications, it is an ideal surgical approach for the treatment of portal hypertension.

Humans ; Minimally Invasive Surgical Procedures ; utilization

Objective To study the increased radiosensitivity of tumor cells by triterpene acids of loquat leaf (TAL) and mechanism.Methods C6 and MG63 cells were pretreated by TAL,and then were exposed to X-rays at 1,2,3,5,7 Gy.Clonogenic assay was used to evaluate those tumor cells survival fraction (SF) to calculate the sensitization enhancement ratios (SER) of TAL.The cellular micronuclei ratios of tumor cells were analyzed by micronuclei assay.Additionally,the changes of Rad51 and XRCC4 levels were observed by RT-PCR and Western blot.Results D0 values were decreased to 1.31 and 2.85 Gy in C6 and MG63 cells by TAL pretreatment respectively.The SER value of the effect of TAL on C6 and MG63 cells was 1.73 and 2.04,respectively.There was a statistical difference in the cellular micronuclei ratios between tumor cells with TAL above 2 Gy and those without TAL (C6:t =-8.372--2.476,P ＜0.05 ; MG63:t =-4.03--2.557,P ＜ 0.05).TAL attenuated the expression of XRCC4 at transcriptional and translational level,but not for Rad51,a key gene in homologous recombination repair (HRR).Conclusions TAL pretreatment could increase the lethal effect of X-rays on tumor cells in vitro.The mechanism might be involved in the inhibition of non-homologous end joining (NHEJ).