TSPAN8 is involved in lipid metabolism in non-alcoholic fatty liver disease in mice / 南方医科大学学报

OBJECTIVE@#To investigate the changes of tetraspanin 8 (TSPAN8) expression levels and its role in lipid metabolism during the development of non-alcoholic fatty liver disease (NAFLD).@*METHODS@#Thirty male C57BL/6J mice were randomly divided into normal diet group and high-fat diet (HFD) group (n=15), and after feeding for 1, 3, and 6 months, the expression levels of TSPAN8 in the liver tissues of the mice were detected with Western blotting. In a HepG2 cell model of NAFLD induced by free fatty acids (FFA), the effect of TSPAN8 overexpression on lipid accumulation was examined using Oil Red O staining and an automated biochemical analyzer, and the mRNA expressions of the key genes involved in lipid metabolism were detected using qRT-PCR.@*RESULTS@#Western blotting showed that compared with that in mice with normal feeding, the expression of TSPAN8 was significantly decreased in the liver tissues of mice with HFD feeding for 3 and 6 months (P < 0.05). In HepG2 cells, treatment with FFA significantly decreased the expression of TSPAN8 at both the mRNA and protein levels (P < 0.01). TSPAN8 overexpression in FFA-treated cells showed significantly lowered intracellular triglyceride levels (P < 0.001) and obviously reduced mRNA expression of fatty acid transport protein 5 (FATP5) (P < 0.01). The expression of FATP5 was significantly increased in FFA-treated cells as compared with the control cells (P < 0.001).@*CONCLUSION@#TSPAN8 is involved in lipid metabolism in NAFLD, and overexpression of TSPAN8 may inhibit cellular lipid deposition by reducing the expression of FATP5.

Effect of Ginsenoside Rg1 on Lipid Uptake and Oxidation in HepG2 Cells of Nonalcoholic Fatty Liver Disease / 中国实验方剂学杂志

Objective:To investigate the effect and mechanism of ginsenoside Rg1（G-Rg1）in ameliorating lipid uptake and oxidation in HepG2 cells induced by free fatty acids (FFA). Method:HepG2 cells were divided into normal group, model group，low-dose ginsenoside Rg1 group (25 μmol·L-1) and high-dose G-Rg1 group (50 μmol·L-1). HepG2 cells were treated with 1 mmol·L-1 free fatty acid for 24 h to construct the NAFLD cell model, and then treated with 25，50 μmol·L-1 G-Rg1 for 24 h. The effect of G-Rg1 on HepG2 cell activity was determined by cell counting kit-8（CCK-8） assay. The level of triglyceride (TG) was detected by micro method. The accumulation of lipid droplets was observed by oil red O staining. Quantitative real-time fluorescence polymerase chain reaction (Real-time PCR) and Western blot were used to detect the alterations of key genes and proteins relating to lipid uptake and metabolism. Result:Compared with the normal group, the intracellular TG level and the absorbance of the oil red O staining in the model group were significantly increased (P<0.01). Compared with the model group, G-Rg1 reduced TG and lipid deposition were significantly reduced (P<0.01).Results of Real-time PCR and Western blot showed that compared with normal group, model group peroxisome proliferators-activated receptors gamma（PPARγ），fatty acid binding protein 1（FABP1），fatty acid transport protein 2/5（FATP2/5）and fatty acid translocase（CD36）expressions increased（P<0.05），whereas peroxisome proliferators-activated receptors α（PPARα），carnitine palmitoyltransferase 1（CPT1）and peroxisomal acyl-coenzyme A oxidase 1（ACOX1）expressions decreased（P<0.05）. Compared with the model group, the expressions of PPARγ, FABP1, FATP2, FATP5 and CD36 in the G-Rg1 group were decreased (P<0.05，P<0.01), while the expressions of PPARα, CPT1 and ACOX1 were increased (P<0.05，P<0.01). Conclusion:G-Rg1 can ameliorate lipid deposition in NAFLD cell model by reducing lipid uptake and increasing lipid oxidation.

Acceptability and influencing factors of pre-exposure prophylaxis among men who have sex with men in Guangxi / 中华流行病学杂志

Objective To study the acceptability of pre-exposure prophylaxis (PrEP) to prevent the transmission of HIV among men who have sex with men (MSM) in Guangxi, China.Methods Snow-balling methods were used to recruit 650 MSM in Guangxi. Questionnaires and interview were administrated to these 650 men, using a self-designed questionnaire and face to face interviews to collect information on HIV-related risk behaviors, knowledge and acceptability of PrEP.effective, safe and free of charge', 597 (91.9%) of the 650 MSM claimed that they would accept it,who refused to use it, most of them said that were afraid of the side-effect and doubted on the effectiveness of PrEP. Data from logistic regression analysis showed that those who had found partners through friends (OR=6.21, P=0.020) and those who would advise his friend to use PrEP (OR=39.32, P=0.000) were more likely to accept PrEP. Those who thought they could protect themselves from HIV infection (OR=0.32, P=0.010) or not having sex with the ones who refused to use a condom (OR=0.34, P=0.010) were less likely to accept PrEP. Conclusion Effectiveness, safety and cost seemed to be the main influential factors related to the acceptability of PrEP. Peer education might improve the acceptability of PrEP.

Comparison of antiviral responses to adefovir dipivoxil therapy of genotype B and genotype C HBV infected patients / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the role of HBV genotypes on their response to adefovir dipivoxil (ADV) antiviral therapy.</p><p><b>METHODS</b>HBV genotypes from 177 HBeAg-positive chronic hepatitis B (CHB) patients were identified and the patients were treated with ADV 10 mg per day for 48 weeks. The clinical data in terms of serum HBV DNA seroclearance, mean HBV DNA reduction (log value), HBeAg loss, anti-HBe seroconversion and serum ALT of those patients were analyzed against their HBV genotypes.</p><p><b>RESULTS</b>Genotype B and genotype C were found in 102 and 65 cases, respectively. The mean HBV DNA reduction in patients with genotype B and genotype C at their treatment times of 12, 24 and 48 weeks was 2.2 log10copies/ml, 2.1 log10copies/ml (P more than 0.05), 2.7 log10copies/ml, 2.4 log10copies/ml (P more than 0.05) and 3.6 log10copies/ml, 3.1 log10copies/ml (P less than 0.05), respectively. At the end of the therapy (48 weeks), 43 (42.2%) patients with genotype B HBV infection and 22 (33.8%) patients with genotype C HBV infection had achieved HBV DNA seroclearance (P less than 0.05).</p><p><b>CONCLUSIONS</b>Our results suggest that genotype B HBV has a better virological response to ADV therapy in HBeAg-positive chronic hepatitis B patients than that of genotype C. Longer terms of ADV treatment are needed to confirm this conclusion.</p>

Role of TMS5: staphylococcal multidrug-efflux protein QacA / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>QacA, a main exporter mediating the multidrug-resistance of Staphylococcus aureus to a variety of antiseptics and disinfectants, possesses a topology of 14 alpha-helical transmembrane segments (TMS). Our study aimed to determine the importance and topology of amino acid residues in and flanking the cytoplasmic end of TMS5.</p><p><b>METHODS</b>Site-directed mutagenesis was used to mutate 5 residues, including L146, A147, V148, W149 and S150, into cysteine. A minimum inhibitory concentration (MIC) and transport assay with or without N-ethylmaleimide (NEM) were performed to analyse the function of these mutants.</p><p><b>RESULTS</b>All of the mutants showed comparable protein expression levels. MIC analysis suggested that mutant W149C showed low resistance levels to the drugs, but the mutations at L146, A147, V148, and S150C had little or no effect on the resistance level. And the results of the fluorimetric transport assay were in agreement with those of MIC analysis, that is to say, W149C did not allow transport to the substrates to be tested, while the other mutants retained significant transport ability. The reaction of the different mutant proteins with Fluorescein-NEM revealed that the mutant L146C was highly reactive with NEM; the W149C and S150C mutants were moderately reactive; A147C was barely reactive and V148C showed no reactivity.</p><p><b>CONCLUSIONS</b>The study identified that residues W149 and S150 situated at the interface of the aqueous: lipid junction as functionally important residues, probably involved in the substrate binding and translocation of QacA.</p>

Genotyping 238 HBV strains using type-specific primer PCR combined with type-specific nucleotide analysis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To establish a set of suitable and reliable methods for HBV genotyping and to study the distribution of HBV genotypes.</p><p><b>METHODS</b>Type-specific nucleotides were searched through alignment of S genes (more than 1000 sequences) listed in GenBank. Then, type-specific primers were designed and type-specific primer PCR was used to genotype the 238 HBV strains. S genes of the untyped strains were further amplified and sequenced to find out their genotypes with type-specific nucleotide analysis.</p><p><b>RESULTS</b>All the 238 HBV strains were genotyped. 159 (66.8%) cases were genotype B, 69 (28.9%) were genotype C, 6 (2.5%) were mixtures of genotypes B and C and 4 (1.6%) were mixtures of genotypes B and D. No genotypes of A, E, F, G, and H were found.</p><p><b>CONCLUSION</b>Genotypes B and C are the most common types for HBV strains. Mixtures of genotypes B and C or genotypes B and D coinfection rarely existed. There is no relationship between the gender of the patients and HBV genotypes (X2 = 0.794, P more than 0.05).</p>

Cloning and expression of the hy1 gene of Enterococcus faecium and immunologenicity of the Hy1 fusion protein / 中华传染病杂志

Objective To construct a recombinant expressing plasmid of the hy1 gene of Enterococcus faecium and to express the recombinant Hy1 protein in E.coil.To explore the immune response in mice fed orally with Hyl protein.Methods hy1 gene was amplified by polymerase chain reaction(PCR)and inserted into a prokaryotic expression vector pQE-30.The recomhinant plasmids were transfected into DH5_?to express Hy1 fusion proteins,which were purified by Ni~--column. Western blot was employed to confirm the immunogenicity of the purified protein.Mice were immu- nized by feeding with the fusion protein.The concentrations of antigen-specific antibody in the serum, mucosal fluid and faces were detected by enzyme-linked immunosorbent assay(ELISA).The role of these antibodies in the anti-infection response was evaluated after the mice were challenged with TX0016.Results hy1 gene was sequenced as 1662 bp,the fusion protein encoding polypeptides of 553 amino acid residues.The relative molecular weight was 60 000 when it was determined by sodium dodecylsulfatepo-lyacry-lamide gel electropboresis(SDS-PAGE).The dissolvable expression protein accounted for 38% of total cell protein.After processed by affinity chromatography,the purity of fusion protein was above 92%.Western blot analysis confirmed that fusion protein could be specifically recognized by the anti-TX0016 serum.The concentrations of serum IgA,serum IgG,faeces sIgA and intestmucosal fluid sIgA was 0.365?0.048,0.431?0.064,0.743?0.056 and 1.112?0.113 respectively in hy1 groups and 0.051?0.013,0.098?0.019,0.102?0.032 and 0.187?0.051 respectively in control group.The differences were statistically significant.The mice survival rate after TX0016 challenge was 70% in hyl group and 50% in control group.There was significant difference between these two groups.Conclusion The results indicate that oral immunization with hyl can induce effective mueosal immune response and produce high level sIgA.

Surveillance of bacterial resistance from a hospital in Chongqing from 2004 to 2005 / 中国感染与化疗杂志

Objective To investigate the antimicrobial resistance of clinical isolates from a hospital in Chongqing during one year according to CHINET project.Methods Disc diffusion test (K-B method) was employed to study the antimicrobial resistance. WHONET5 was used for data analysis.Results In one year period from 2004 to 2005,690 non-duplicate isolates were collect- ed.Enterobacter isolates showed the lowest resistance rate to imipenem and meropenem.About 37.5% of E.coli and 31.4% of K.pneumoniae isolates produced ESBLs,respectively.All ESBLs-producing strains were susceptible to imipenem and mer- openem.About 37.2%,39.4% and 48.9% of P.aeruginosa isolates were resistant to imipenem,meropenem and ceftazidime, respectively.Pandrug-resistant (PDR) P.aeruginosa was isolated from our hospital.All strains of A.baumannii were sus- ceptible to imipenem and meropenem.About 37.7% of A.baumannii were resistant to cefoperazone-sulbactam.Twenty-nine strains showed the same resistant pattern among non-susceptible strains of A.baumannii,mainly derived from 2 clones by PFGE analysis.Conclusions The surveillance results suggest that prevalent strain resistant to cefoperazone-sulbactam may pres- ent in some ICUs.Resistance rate to cefoperazone-sulbactam increased significantly.