To explore the effect of products of nan A gene on the changes of cell surface carbohydrates of the chinchilla eustachian tube after infection with Streptococcus pneumoniae. Methods Using lectin histochemical techique to compare the changes of the cell surface carbohydrates in the chinchilla eustachian tube after infection with S.pneumoniae D39 or ?NA1 mutant. Results The labeling pattern revealed that the staining with Limax flavus agglutinin (LFA) and Sambucus nigra agglutinin (SNA) was decreased in epithelium of the eustachian tube in the D39 cohort compared to the uninfected control, which indicated that the normal terminal sialic acid residue were removed. Concurrently, the increased staining with wheat germ agglutinin (WGA), succinylated wheat germ agglutinin (Succ WGA), Bandeiraea simplicfolia lectin II (BSL II), peanut agglutinin (PNA) and Erythrina cristagalli lectin (ECL) was observed in the lumen surface of eustachian tube subsequent to intranasal inoculation with D39. However, the ?NA1 neuraminidase deficient mutant did not show any significant changes in the lectin labeling patterns as compared with those of the control cohort. Conclusions The products of the nan A gene play an important role in the changes of cell surface carbohydrates and thus may be responsible for the colonization in the chinchilla eustachian tube after infection with Streptococcus pneumoniae.

Nucleoside and nucleotide analogs (NAs) have been successfully used for treatment of chronic hepatitis B. Hepatitis B virus (HBV) replication is now recognized as the key driver of liver injury and disease progression, so the primary aim of treatment for chronic HBV infection is to maximize sustained suppression of HBV replication to undetectable levels. The long-term treatment has also been shown to achieve substantial histological improvement and regression of liver fibrosis or cirrhosis, and reduction of hepatocellular carcinoma. This paper has reviewed the necessity, clinical benefits, and the management of long-term treatment for chronic hepatitis B.
Antiviral Agents ; Carcinoma, Hepatocellular ; Hepatitis B virus ; Hepatitis B, Chronic ; Humans ; Liver Cirrhosis ; Nucleosides ; Virus Replication

Objective To detect rpoB mutations in rifampin resistant mycobacterium tuberculosis strains isolated from Shanghai, and to evaluate the implication of applicating line probe assay (LiPA). Methods A fragment (213bp) of rpoB gene of 58 Mycobacterium tuberculosis isolates was amplified and sequenced, 18 rifampin resistant strains and 10 susceptible strains were selected to detect mutation by LiPA. Results Mutations of rpoB gene in 17 strains of the 18 rifampin resistant isolates were found by LiPA, and there were no mutations in any of the 10 susceptible strains. The sensitivity of LiPA was 94.4% and the concordance with drug susceptibility of Mycobacterium tuberculosis was 96.4%. Conclusions LiPA is a useful method for the rapid detection of mutations of rpoB gene in rifampin resistant Mycobacterium tuberculosis with high sensitivity.

Objective To explore the fluctuation of cytokine mRNA expression level in a novel T-cell-mediated immune hepatic fibrosis model induced by repeatedly injections of Concanavalin A in BALB/c mice. Methods BALB/c mice were divided into different groups. Model group mice were injected weekly up to 20 weeks with Concanavalin A (15mg/kg), via retro-orbital venous plexus under ether anesthesia. Normal control group mice were treated in the same manner weekly with normal saline. Twenty-four hours after Concanavalin A challenge at 1, 5, 12 and 20 week, 8 mice from each time were killed by cervical dislocation, repectively. The livers of different group were excised and fixed in 10% formalin for HE staining and Gomori Ag staining or frozen in optimal cutting temperature (O.C.T.) media in liquid nitrogen for immunohistochemical staining for CD4 +T or CD8 +T cell. After extracting total RNA from liver tissues, IL-2, IL-4, IL-10 and transforming factor ?1 messenger RNA were amplified by reverse transcription polymerase chain reaction. PCR products were electrophoresed on agrose containing ethidium bromide and visualized under ultraviolet light. Densitometric RT-PCR data were standardized with ?-actin signals. Results The histological change of HE staining and Gomori Ag staining indicated the fibrogenesis in model group mice. Immunohistochemical staining for CD4 + or CD8 + T cell indicated that the infiltrating lymphocytes in liver parenchyma were mainly CD4 +T lymphocytes. IL-2 mRNA expression level only increased after the first injection of Concanavalin A. The expression levels of IL-4, IL-10 and transforming growth factor ?1 mRNA significantly increased over the whole experiment period as compared with control group. Conclusions Repeated administration of Concanavalin A can induce T-cell-mediated immune hepatic fibrosis model in BALB/c mice. The expression levels of IL-4, 10 and TGF-?1 increase over the whole experiment period and may play an important role in creating mouse fibrotic model.

Objective To investigate the signaling mechanisms underlying synergistic induction of MUC5AC mucin by nontypeable Haemophilus influenzae(NTHi)and epidermal growth factor (EGF).Methods The expression of MUC5AC was measured by real-time quantitative polymerase chain reaction(PCR)and Luciferase assay.Western blot was performed to examine the synergistic induction of phosphorylation of P38,extracellular signal-regulated kinase(ERK)and P21-activated kinase(PAK)4 or the effect of dominant negative mutant of PAK4 on the synerglstic induction of phosphorvlation of P38 mitogen-activated protein kinase(P38MAPK)and ERK in HM3 cells treated with NTHi and EGF.Luciferase asgay was also performed to examine the effect of P38,ERK inhibitors or dominant negative mutants of P38MAPK and ERK on synergistic enhancement of NTHi-induced MUC5AC up-regulation by EGF at transcriptional level.Real-time quantitative PCR was performed to examine the effect of PAK4 siRNA on synergistic induction of NTHi-induced MUC5AC up-regulation by EGF.ResuIts NTHi induced MUC5AC mucin expression at both mRNA and transcriptional levels.Synergistic induction of phosFIhorylation of P38MAPK,ERK and PAK4 were observed in HM3 cells treated with NTHi and EGF.Either SB203580,a specific inhibitor for P38MAPK or PD98059,a specific inhibitor for ERK inhibited synergistic induction of MUC5AC at transcription level.Furthmore, overexpressing dominant negative mutant of P38MAPK and ERK also inhibited synergistic induction of MUC5AC at transcription level. PAK4 siRNA inhibited the synergistic induction of MUC5AC by NTHi and EGF. Overexpressing dominant negative mutant of PAK4 also reduccd synergistic induction of phosphorylation of P38 and ERK. Conclusion Synergistic induction of MUC5AC mucin by NTHi is up-regulated by EGF via PAK4-dependent P38MAPK and ERK pathways.

Objective To investigate the variability of katG gene in Mycobacterium tuberculosis strains isolated in China,and screen the new isoniazid resistance related mutation sites meanwhile. Methods 429 clinical Mycobacterium tuberculosis isolates were included in our research.PCR-RFLP method was applied to screen for the S315T mutation firstly.Whole katG gene sequencing was done in those resistant strains without S315T mutation to explore the unknown mutated sites associated with isoniazid resistance.Results S315 mutation were found in 76.9% (166/216)resistant stains. Complete or part deletion of katG gene was detected in 2 highly-resistant isolates.Sequencing in 48 resistant strains showed that 315,463 and 234 sites were the most frequent mutation sites,other sites were also found but distributed dispersedly with low prevalence rate as less than 5%.Besides S315T, S315N were also common in China (8.7%).The most common variation is still site mutation.Con- clusions The results from the study of genotypes associated with most common clinical resistant phe notypes can be helpful to develop new methods to detect the resistant M.tuberculosis.

Objective To assess the epidemiological relatedness on an outbreak of Enterococcus facium sepsis between humans and pigs based on genomic analysis. Methods Two bacterial isolates recovered randomly from the blood of one patient and one pig were analyzed for homogeneities by comparison with 16S rRNA gene sequences in the GeneBank. Moreover, The extracted genomic DNA was digested with the 20 U SamI enzyme respectively, then their interrelationship was performed according to the pulsed field gel electrophoresis. Results Sequences determined from both human and pig isolates were 100% identical and most closely related to E. facium , diverging from the prototype sequence by one nucleotide (99.9% similarity) and displayed indistinguishable pulsed field gel electrophoresis patterns. Conclusions These data demonstrate epidemiological relatedness of the bacterial isolates, and suggest spread of an E. facium -related sepsis outbreak from pigs to humans.

For establish a sensitive and specific method to diagnose schistosomasis,we used the PCR and NEST-PCR to detect the Schistosoma japonicum 5D gene encoding an immunogenic miracidial antigen in samples from schistosomiasis patients and animal models.The PCR protocol gave positive re- sults in liver.spleen and stool samples,but the serum from patients and animal models as well as plasma and peripheral blood mononuclear cells from animal models were negative.The results suggest that S. japonicum DNA not exist in peripheral blood.

Objective To develop a new multiplex allele-specific PCR(MAS-PCR) assay to detect mutation in codon 315 of katG gene of Mycobacterium tuberculosis , mutation in this codon has been reported to be able to account for the Mycobacterium tuberculosis clinical isolates resistant to isoniazid(INH).Method Based on the sequence of katG gene of Mycobacterium tuberculosis , three specific primers are designed to carry out the MAS-PCR, 84 purified DNA preparation with known katG 315 variation detected by PCR-restriction fragment length polymorphism (PCR-RFLP) are used to optimize PCR.Results 84 Mycobacterium tuberculosis clinical stains are detected by the MAS-PCR and PCR-RFLP, respectively.The sensitivity of detection by MAS-PCR is 77.8%,and the specificity is 95.2%.katG mutation S315N(AGC→AAC), neglected in RFLP, can be detected by MAS-PCR.Conclusion MAS-PCR assay is sensitive, specific, economic and easy to carry out , can be used in clinical laboratories to detect the INH-resistant Mycobacterium tuberculosis strains.