Objective To screen cell growth and senescence-related genes of the parasitic pmtist Trichomonas vaginalis,we launched an EST program and isolated two cDNA clones from a T.vaginalis cDNA library,which showed high homology in deduced amino acid sequences to yeast Sir2 and designated as TvSir2 and TvSir2-like.Method The cDNA sequence of TvSIR2 had a length of 1034 base pairs (bp) with an open reading frame of 915 bp,and TvSIR2-like,1214 bp with an open reading frame of 1116 bp.Result The two deduced amino acid sequences shared all the three conserved cole domains with yeast Sir2 and its homologues,suggesting that the two clones were Sir2 homologues. A cDNA fragment from each cDNA clone was subvloned into the expression vector pET-41a.The expression of the fusion proteins in E.coli BL21 stains was induced by isopropylthio-β-D-galactoside (IPTG).Two anti-sera were prepared by immunizing two guinea pigs with the purified fusion proteins, Western-blot analysis demonstrated that each anti-serum reacted with the corresponding recombinant protein and detected a clear band (TvSir2,34 000 Mr;TvSir2-like,42 000 Mr)in protein extracts of the protist.Immunofluolescence techniques showed that TvSir2 and TvSir2-like proteins were both localized in the legions of perinuelear (ER) and Golgi complex.Conclusion Our data suggest that TvSir2 and TvSir2-like were two members of Sir2 family.Their biological functions in the protist would be further studied.

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 clone and express the valuable Clonorchis sinensis antigen molecules which can be applied to the diagnosis of clonorchiasis. Methods Based on the sequences (Genbank) No. AF271091 (CysA) and No.AF093242 (CysB), primers were designed to amplify the two C. sinensis cysteine proteinase genes and expressed in E.cloi. The expressed proteins were purified by affinity chromatography and then tested for their immunological characters.Results The two genes were successfully cloned and expressed. Western blot showed that CysB had strong reaction with clonorchiasis sera and very weak reaction with schistosomiasis sera, while CysA showed no reactivity with the probed sera. Immunohistochemistry showed that both proteins were mainly located in adult worm intestines and the intrauterine eggs.Conclusions The results suggested that, of the two expressed C. sinensis proteins, CysB had good antigenic reactivity against sera from patients. It is a potential candidate of diagnostic antigens for clonorchiasis.

Objective The aim of this study is to clone and characterize a novel Trichomonas vaginalis Rabl-like geue (TvRabl-like) with a small intron. Methods The eDNA clone of TvRabl-like gene was isolated from a cDNA expression library and sequenced. Sequence analysis was performed using BLASTP, RPS-BLAST ClustalW programs.Phylogenetic analysis was carried out by MEGA3 program. The genomic DNA and mRNA of TvRab1-like gene were amplified using PCR and RT-PCR techniques respectively and also sequenced. Results The eDNA sequence of TvRab1-like gene had a length of 705 base pairs with an open reading frame of 603 bp. The deduced amino acid sequence from the open reading frame possessed 200 residuals corresponding to a putative M.W. 22532.2 and an estimated pl of 7.4. Sequence analysis demonstrated that TvRab1-like gene showed the highest homology to T. vaginalis Rabla (63% identity and 79% similarity) and the Rabl subfamily of other species, suggesting that the deduced amino acid sequence from this cDNA clone was a Rabl isoform. Phylogenetic analysis showed that TvRab1-like gene was clustered with T.vaginalis Rab1 subfamily in the phylogenetic tree. Sequencing of the PCR product of genomic DNA revealed that the genomic DNA possessed a 25 bp intron which contained canonical 5' GT-AG-3' and branch site motifs as those larger introns found in T.vaginalis and other eukaryotes. The analysis of RT-PCR products demonstrated the presence of the unspliced mRNA and spliced mRNA, indicating that there was a intron. Conclusion These data suggest that TvRabl-like gene belongs to T.vaginalis Rabl subfamily. TvRabl-like gene possesses a 25 bp splieeosomal intron which is the smallest one of the introns identified in this deepest-branching protist and might be the shortest intron of eukaryotes. Study of those introns might provide more insights into the intron evolution of eukaryotes.

Objective Apoptosis or programmed cell death(PCD) has been studied extensively in multicellular organisms,however,very little is known about the molecular mechanisms by which apoptosis occurs in unicellular protozoan parasites.The aim of this study is to characterize the apoptosis or PCD of Trichomonas vaginalis induced by metronidazole (MTZ).Methods T. Vaginalis strain cultures were treated with various concentrations of MTZ and the number of viable cells were determined at different time intervals.The genomic DNA of MTZ treated T. Vaginalis was extracted and DNA fragmentation was analyzed.TUNEL assay was carried out to detect the endonuclease activity in T. Vaginalis after MTZ treatment.Flow cytometric analysis was used to analyse the phosphatidylserine (PS) exposure of T. Vaginalis.Results Metronidazole (MTZ) induced an apoptotic-like cell death in T. Vaginalis.This apoptotic-like cell death was demonstrated by cell shrinkage,phosphatidylserine exposure,and nuclear chromatin condensation.However, no oligonucleosmal DNA laddering was detected.Conclusion The regulatory pathway of apoptotic cell death in T. Vaginalis may be different from multicellular organisms.The determination of protozoan apoptotic pathways leading to cell death might ultimately allow the identification of new therapeutic targets.

Objective Rab11 GTPases play an essential role in regulating membrane trafficking pathways in eukaryotic cells. Nonetheless, there has been little work done on characterizing the transport machinery of Trichomonas. The aim of this study is to clone and characterize a Rab11 gene of Trichomonas vaginalis.Methods A cDNA expression library was constructed with T. vaginalis total RNA. A cDNA clone, which showed a high degree of homology with Rab proteins of different species, was isolated and sequenced. Sequence analysis was performed using BLASTP, RPS-BLAST and ClustalW programs. The genomic DNA corresponding to the cDNA sequence was amplified using PCR techniques and following by sequencing. Results cDNA with a length of 710 base pairs and an open reading frame of 636 bp was obtained. The deduced amino acid sequence from the open reading frame was found to possess 211 residuals. Sequence analysis demonstrated that this cDNA clone was homologous to the Rab11 subfamily of different species (60% identity and 79% similarity with Arabidopsis thaliana Rab11c, 58% identity and 78% similarity with human Rab11b), and that the amino acid sequence contains all the well known conserved sequence elements of Rab family. Specific Rab motifs were also detected in the deduced amino acid sequence. Phylogenetic analysis showed that its closest homologues are Rab11 proteins from other species. Sequencing of the PCR product of genomic DNA revealed that the genomic DNA sequence encompassing the putative 5'-ATG and 3'-stop codon is identical to the cDNA sequence.Conclusion A cDNA clone corresponding to the T. vaginalis Rab11 gene was obtained.The function of this gene in regulating membrane trafficking pathways of the parasitic protist is still under investigation.

Objective To investigate the polymorphism of human cytomegalovius UL143 gene of low passage clinical isolates in Guangzhou,China.Method PCR was performed to amplify the entire HCMV ULl43 gene region of 3 clinical isolates,which had been proven by multiplex PCR.The amplification products were cloned into pMD18-T-Vector and subjected to sequencing.The result of DNA sequences were analyzed together with the one of published homologous sequences in GenBank from 14 clinical isolates.Result There were several stop codons in UL143 gene due to a base deletion in open reading frame (ORF) of D3 isolate,which could lead to produce non-functional protein.UL143 ORF of Toledo isolate consisted of 279 nueleotides,encoding a protein with 92 amino acids.UL143 ORFs of other isolates consisted of 252 nueleotides,encoding a protein with 83 amino acids.The DNA sequences were quite conserved and all the variations were base substitution.The amino acid sequences of different isolates were highly conserved.with variation of 1.2%-2.4%.There were no additional or deleted sites of post translational modification of UL143 protein in all clinical isolates except Toledo isolate.There were some differences in the secondary structure among different isolates.The isoelectric point of UL143 protein of all clinical isolates except Toledo isolate was 8.75.Conclusion All DNA and deduced amino acid sequences of UL143 gene shared great similarity among HCMV clinical strains regardless of their polymorphism.

Objective To evaluate the influence of the storing time of venous blood samples on the differential count of WBC by Sysmex XE-2100 hematology analyzer. Methods At room temperature, the precision of the differential count of WBC by Sysmex XE-2100 hematology analyzer were tested. 38 samples were taken the differential count of WBC by Sysmex XE-2100 hematology analyzer after stored for 0, 2, 4, 8, 24 and 48 h. Differential count of WBC was also taken under microscope for comparison. Results The precision of differential count of WBC by Sysmex XE-2100for all the samples was in the allowable range. The correlation coefficient of the differential count of WBC by two methods for neutrophils, lymphocytes, monocytes, eosinophils and basophils were 0.9859, 0.9775, 0.8053, 0.8695and 0.5243 (P<0.01). There was insignificant difference in the test at 8h, very significant difference of MONO and EOS at 48 h. Differences of EOS, MONO between two methods were significant increased at 8 h. Conclusion At room temperature, the differential count of WBC of venous blood samples by Sysmex XE-2100 hematology analyzer should finish within 8 h.

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.