Objective To construct the eukaryotic expression plasmid for the expression of human Connexin26 in COS-7 cells.Methods Total RNA was isolated from human peripheral blood lymphocytes and used as template for the PCR cloning of the human Connexin26 gene.The human Cx26 cDNA containing the 678 bp whole coding region of the human Connexin26 gene was amplified by PCR using specific primers and cloned into the pCI-neo vector to construct the recombinant eukaryotic expression plasmid,pCI-Cx26.The recombinant plasmid was identified by restriction endonuclease digestion,and transfected into COS-7 cells by liposome.The expression of Cx26 mRNA and the protein were analyzed by RT-PCR and SDS-PAGE,respectively.Results Restriction endonuclease digestion analysis verified successful construction of the recombinant plasmid,pCI-Cx26.The expression of Cx26 mRNA and protein in the transfected COS-7 cells were detected by RT-PCR and SDS-PAGE,respectively.Conclusion The eukaryotic expression plasmid for human Cx26 has been constructed successfully with the capability of expression in COS-7 cells.

Objective To determine the taxonomic position of medically important gamasid mites and to compare numerical taxonomy with the traditional systematics in the classification of gamasid mites. Methods Based on hierarchical cluster analysis, numerical taxonomy was applied to study fifty-seven species of medically important gamasid mites. Results The results of cluster analysis based on squared euclidean distance showed that Hirstionyssus Fonseca and Echinonyssus Hirst should be separated from Laelapidae Berlese and formed an independent family. The taxonomic position of the remaining species remains the same as those in the traditional systematics. Conclusion Numerical taxonomy can objectively reflect the taxonomic position of the medically important gamasid mites. The result of classification by numerical taxonomy is consistent with traditional systematics for gamasid mites.

Objective To evaluate the measurement of kappa and lambda immunoglobulin free light chains(FLC) in patient samples using a new enzyme-linked immunosorbent assay for early diagnosis of multiple myeloma.Methods An ELISA method for quantifying kappa and lambda free light chains were used to study serum and urine samples from patients with multiple myeloma, and the results were compared with those obtained using immunofixation electrophoresis and nephelometric immunoassay methods. Results The FLC-ELISA method had great successful rate in identifying the multiple myeloma in all 40 myeloma patients. In contrast,immunofixation electrophoresis and nephelometric immunoassay could only identify 57.5% and 85.5% of the multiple myeloma in all the myeloma patients,respectively. Furthermore, retrospective diagnosis of specimens obtained from patient indicated that the ELISA method could help early diagnosis of the disease by over two years. Conclusion The ELISA method for measuring free light chains is sensitive, accurate and reproducible. Therefore it is a useful tool for early diagnosis of multiple myeloma,monitoring the disease progression and evaluating treatment responses.

Objective To detect circulating antigen (Cag) for diagnosing neurocysticercosis. Method ELISA was performed with monoclonal antibody 4B6 against the cyst fluid antigen of Cyticercus cellulosae for detecting Cag in serum and/or cerebrospinal fluid (CSF) of patients with neurocysticercosis or with other diseases. Results In the group of 82 cases of neurocysticercosis, the positive rate of serum Cag was 79.2% (65/82) and the positive rate of CSF Cag was 100% (26/26). After chemotherapy for 20 cases with positive serum Cag, the titer of serum Cag in 17 cases dropped to zero(85% ). Cag could not be detected in specimens from patients with other diseases. Conclusion These results indicate that the determination of Cag, especially of the CSF Cag, is useful for the diagnosis of neurocysticercosis and the drop in serum Cag is a good parameter for the evaluation of the effectiveness of chemotherapy.

The article clarified, according to the recent research results which have been done in Poyang Lake region of Jiangxi province, bovines are the most important animal hosts of Schistosoma japonicum and infected bovines are main infectious sources of Schistosomiasis in Poyang Lake region. Spring (March to June) is the " cross transmission stage" between definitive host and intermediate host, that is, spring is not only the susceptible season of infection for livestock and human, but also is the susceptible season of infection for snails. In flood season (July to August), the transmission of Schistosomiasis between livestock and snails belong to " low level phase" . Autumn (September to Octber) is the second seasonal peak of cercariae and is the susceptible season of infection for livestock and human. Winter(November to Feburary in next year) is the non- susceptible season of infection. Most of the susceptible zones of infection for livestock, human and snails are the marshlands near the endemic villages.

Objective To understand the primary structure and potential antigenic epitopes of antigen Pf332(Ag332) of P.falciparum iso late FCC1/HN.Methods　Based on the published Pf332 gene sequence , nine pairs of primers were designed for the PCR amplification of the Pf332 gen e fragments from genomic DNA of P.falciparum isolate FCC1/HN. The amplified gene fragments were subcloned into pMD-18T vectors and sequenced. The sequences were aligned using DNAstar software to obtain the full-length sequence of the gene Pf332. The primary structure and sequence homology of Ag332 were analyzed by SAPS, Tmpred, SingalP and Blastn programs. Three fragments, R0, R1 and R2, cor responding to nt#9595-10083, nt#10339-10767 and nt#10855-11247 of Pf332 gene were subcloned into the eukaryotic expression vector pcDNA3-S separately. The Balb/c mice were immunized with pcDNA3-S-R0, pcDNA3-S-R1 and pcDNA3- S-R2 separately, and the expressions of the recombinant proteins were detected by immunohistochemistry assay. The protective immune responses elicited by DNA I mmunization were analyzed by ELISA and parasite growth inhibition tests in vitro .Results　Nine Pf332 gene fragments were specifically amplif ied, subcloned into pMD-18T vectors and sequenced. Pf332 gene of the P.falci parum isolate FCC1/HN was 16,377 bp in length, encoding a protein of 5,458 ami no acids, about 615.28kDa. The Ag332 contains 17 regions of highly degenerated Glu-rich repeats, with 30.18% Glu in total amino acids of Ag332. Ag332 of P.falciparum isolate FCC1/HN and 3D7 exhibited 94.55 % homology in amino acid residues. The results of immunohischemistry assay showed that R0, R1 and R2 were expressed in mice muscle tissue. The amount of IgG antibody of the groups immu nized with pcDNA3-S-R0, pcDNA3-S-R1 and pcDNA3-S-R2 were higher than those of blank and pcDNA3 groups (P＜0.05). The result of parasite growth inhibition test showed that the immunized sera at 1∶5 dilution of groups of pcDNA3-S-R0, pcDNA3-S-R1 and pcDNA3-S-R2 had an incomplete inhibitor y effect on P.falciparum growth. Conclusion　The antigen Pf332 is an large protein containing highly degenerated Glu-rich repeats. Pf332 gene fragments, R1 and R2 encoding potent antigenic epitope repeats.

Three forms of the major surface antigen (SAG1)of Toxoplasma gondii, that is the membrane form, the secrete form and the intracellular form, were constructed and used to immunize BALB/c mice. The humoral response in the mice immunized with the membrane form and the secrete form of SAG1 appeared earlier and stronger than those mice immunized with the intracellular form. Result from the challenging infection demonstrated that the protection in the mice immunized with the membrane and the secrete forms was also stronger than in the mice immunized with the intracellular form. We suggest that the immune efficiency of the three forms of SAG1 in the mouse model is different.

Objectives The ferredoxins are iron-sulfur proteins, which function in electron transfer reactions in a variety of systems and participate in the activation of the antimicrobial agent metronidazole. The aim of this study is to clone and characterize ferredoxin genes of Trichomonas vaginalis. Methods A cDNA expression library was constructed with T. Vaginalis total RNA. Hundreds of cDNA clones were isolated and sequenced. Sequence analysis was performed using BLAST programs, ClustalW program, etc. Results One of the cDNA clones, which has homology with T.vaginalis ferredoxin, was further analyzed. This cDNA clone has an open reading frame of 312 base pairs. The deduced precursor protein contains 103 amino acid residues with a hydrogenosome targeting sequence (MLSQCSPLRF) at the N-terminal end. The primary sequence analysis revealed that this new ferredoxin (TvFd2) has a high homology (69% identity) to the previous reported T.vaginalis ferredoxin(TvFd). Interestingly, TvFd2 is homologous to both the two subclasses of (2Fe-2S) ferredoxins, the oxidase ferredoxins and the photosynthetic ferredoxins,but with low similarity. The conserved four-cysteine residues, which are predicted to form the iron-sulfur cluster,are arranged in a typical pattern of (2Fe-2S)ferredoxins(-C-X5-C-X2-C-Xn-C-). Conclusion These data show that TvFd2 is a putative new (2Fe-2S) ferredoxin of T.vaginalis. Its biological function remains to be studied.

Objective To explore immunological mark and the outcome of disease after pharmacological treatment in human NCC with praziquantel. Methods 35 patients were treated with praziquantel for 6 months. Levels of serum IL-2,IFN-γ, IL-12, IL-5, IL-10 and TNF-α were measured before and after treatment. Results Th1 type cytokines IL-2, IFN-γand IL-12 were up regulated after treatment( P ＜ 0. 01 ) . Levels of TNF-α and Th2 type cytokines IL-5 and IL-10 were remarkable decreased after treatment( P ＜ 0. 01 ). The levels of IL-2, IFN-γ and IL-12 from the patients with good response to the treatment is higher than those with no response to the treatment. Conclusion Th1 type cytokines were up regulated while Th2 type cytokines were down regulated in the NCC patients treated with praziquantel. The protective immunity may be related to the Thl cell activation.

Objective To study the effect of of human cytomegalovirus (HCMV) infection on the expressions of Hox genes.Methods Forty eight kunming mice were randomly divided into infection group (n=32) injected with HCMVAD169 and control group (n=16) injected with saline into their brain.After 7,15,30,and 60 days,the cerebral lesions were observed by pathological method.HCMV antigen was detected by immunohistochemical method and HCMV DNA was detected by polymerase chain reaction (PCR). On the basis of developing HCMV mouse model. reverse trancriptase-polymerase chain reaction (RT-PCR) was applied to determine the expressions of Hox gene in the brains of infected mice.The expression of Hox genes were also analysed with Northern-blot by isotope labelled Hox genes oligonucleotide probes. Results A HCMV infection model was developed and extensive pathological damages in brain tissue of infected mice were observed.Meanwhile.the HCMV-LA and HCMV-DNA were also found in brain tissues of HCMV infected mice.The expression level of Hox genes in control and infected mouse brain were determined by RT-PCR and Northern-blot.RT-PCR and Northern-blot showed that mouse brain expressed Hox-A9,Hox-A10,Hox-A11,Hox-A12,and Hox-A13,but they did not express Hox-B13.After HCMV infection,murine brain was induced to express Hox-B13 gene(P＜0.01),and reached the peak at 30 d after infection.Comparing with the control group,the expression of Hox-A9 and Hox-A11 were down-regulated in infected group (P＜0.05);the expression of Hox-A10 and Hox-A13 were significantly higher in infected groups (P＜0.05).Conclusion The results suggest that HCMVAD169 is able to cause mouse CNS infection and induced the abnormal expressions of Hox genes. which provides more information for understanding the mechanism of congenital abnormal due to HCMV infection and a valuable method of clinical prevention and treatment of HCMV infection.