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Currently, there is still no effective curative treatment for the development of late-stage liver fibrosis. Here, we have illustrated that TB001, a dual glucagon-like peptide-1 receptor/glucagon receptor (GLP-1R/GCGR) agonist with higher affinity towards GCGR, could retard the progression of liver fibrosis in various rodent models, with remarkable potency, selectivity, extended half-life and low toxicity. Four types of liver fibrosis animal models which were induced by CCl4, α-naphthyl-isothiocyanate (ANIT), bile duct ligation (BDL) and Schistosoma japonicum were used in our study. We found that TB001 treatment dose-dependently significantly attenuated liver injury and collagen accumulation in these animal models. In addition to decreased levels of extracellular matrix (ECM) accumulation during hepatic injury, activation of hepatic stellate cells was also inhibited via suppression of TGF-β expression as well as downstream Smad signaling pathways particularly in CCl4-and S. japonicum-induced liver fibrosis. Moreover, TB001 attenuated liver fibrosis through blocking downstream activation of pro-inflammatory nuclear factor kappa B/NF-kappa-B inhibitor alpha (NFκB/IKBα) pathways as well as c-Jun N-terminal kinase (JNK)-dependent induction of hepatocyte apoptosis. Furthermore, GLP-1R and/or GCGR knock-down results represented GCGR played an important role in ameliorating CCl4-induced hepatic fibrosis. Therefore, TB001 can be used as a promising therapeutic candidate for the treatment of multiple causes of hepatic fibrosis demonstrated by our extensive pre-clinical evaluation of TB001.
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Angiostrongylus cantonensis invades the central nervous system (CNS) of humans to induce eosinophilic meningitis and meningoencephalitis and leads to persistent headache, cognitive dysfunction, and ataxic gait. Infected mice (nonpermissive host), admittedly, suffer more serious pathological injuries than rats (permissive host). However, the pathological basis of these manifestations is incompletely elucidated. In this study, the behavioral test, histological and immunohistochemical techniques, and analysis of apoptotic gene expression, especially caspase-3, were conducted. The movement and motor coordination were investigated at week 2 post infection (PI) and week 3 PI in mice and rats, respectively. The cognitive impairs could be found in mice at week 2 PI but not in rats. The plaque-like lesion, perivascular cuffing of inflammatory cells, and dilated vessels within the cerebral cortex and hippocampus were more serious in mice than in rats at week 3 PI. Transcriptomic analysis showed activated extrinsic apoptotic pathway through increased expression of TNFR1 and caspase-8 in mice CNS. Immunohistochemical and double-labeling for NeuN and caspase-3 indicated the dramatically increased expression of caspase-3 in neuron of the cerebral cortex and hippocampus in mice but not in rats. Furthermore, western-blotting results showed high expression of cleaved caspase-3 proteins in mice but relatively low expression in rats. Thus, extrinsic apoptotic pathway participated in neuronal apoptosis might be the pathological basis of distinct behavioral dysfunctions in rodents with A. cantonensis infection. It provides the evidences of a primary molecular mechanism for the behavioral dysfunction and paves the ways to clinical diagnosis and therapy for A. cantonensis infection.
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Animals , Humans , Mice , Rats , Angiostrongylus cantonensis , Angiostrongylus , Apoptosis , Behavior Rating Scale , Caspase 3 , Caspase 8 , Central Nervous System , Cerebral Cortex , Diagnosis , Eosinophils , Gait , Gene Expression , Headache , Hippocampus , Meningitis , Meningoencephalitis , Neurons , Receptors, Tumor Necrosis Factor, Type I , RodentiaABSTRACT
Objective To compare the toxicity of outer membrane vesicles ( OMVs) secreted by Acinetobacter baumannii strains with different drug-resistance spectrums.Methods Four Acinetobacter baumannii strains with different drug-resistance spectrums were collected (strain 33, 3237, B29 and 10), and OMVs produced by these strains were extracted and purified.BCA assay was used to determine the protein concentrations, and RAW264.7 cells were incubated with different concentrations of OMVs for 24 h. Cell viability was measured with CCK-8 assay, and gene expression of tumor necrosis factor-alpha ( TNF-α) , interleukin-6 ( IL-6) , interleukin-1 beta ( IL-1β) , keratinocyte-derived chemokine ( KC) and macrophage inflammatory protein 2 (MIP-2) was assessed by quantitative real-time PCR.One-way ANOVA was used for data analysis.Results According to the result of drug susceptibility test, strain 10 was extensively drug-resistant Acinetobacter baumannii ( XDRAB ) strain, strain B29 was multi-drug resistance Acinetobacter baumannii (MDRAB) strain, while strain 33 and 3237 were non-MDRAB strains.After incubated with different concentrations of OMVs for 24 h, cell viability of RAW264.7 declined with the increase of OMVs concentrations.OMVs released from strain10, B29 and 3237 significantly lowered the cell viability at the concentration of 5 μg/mL, while the cytotoxicity of OMVs released from strain 33 was much weaker, and no remarkable decrease in cell viability was observed even at the concentration of 25 μg/mL.OMVs of all strains induced the release of TNF-α, IL-6, IL-1β, KC and MIP-2 in RAW264.7 cells, and the levels of theses cytokines were increased with the concentration of OMVs.Inflammatory response in cells incubated with OMVs from strain 33 was the weakest, while OMVs from strain 10 induced strongest inflammatory response.KC and MIP-2 levels were significantly higher in RAW264.7 cells incubated with OMVs from strain 10 with a concentration of 5 μg/mL than that incubated with OMVs from other strains ( F=19.094 and 19.032,P<0.05 or <0.01).Conclusions OMVs from Acinetobacter baumannii strains with different drug-resistance spectrums are of different toxicity.OMVs from XDRAB and MDRAB strains have higher toxicities and may induce stronger inflammatory response.
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Objective To evaluate the teaching activity on public health courses from clinical medical students in our university in order to provide a scientific basis for improving the curriculum design and teaching reform. Methods The “Questionnaire on Teaching Evaluation in Public Health Courses”, including teaching attitude, teaching content, teaching methods and teaching effectiveness was designed, and a general investigation was conducted among the clinical medical students of five-year program (840 students) and eight-year program (278 students) in these three aspects to under-stand students' evaluation to the course, who had finished the public health courses, including Preven-tive Medicine, Medical Statistics and Epidemiology (hereinafter referred to as: statistics, epidemiology, prevention) in Sun Yat-sen University. Statistical analysis was made using SPSS 13.0 software. Data analysis methods contain descriptive analysis, T-test, ANOVA, LSD, SNK, hierarchical logistic regres-sion analysis, etc. Results The overall score of teaching evaluation is (4.04±0.60). Differences exist between the evaluation in the five-year medical students and the eight-year medical students. The P values were 0.000 (Medical Statistics), 0.269 (Epidemiology), 0.047 (Preventive Medicine). The com-parison of scores among the four dimensions shows: Teaching effectiveness β' effectiveness. Conclusions Clinical Medical students' overall evaluation on the public health courses offered by this university was good. Teaching effectiveness and teaching methods still need improvement. Teaching contents are the most influential factor of overall teaching satisfaction, followed by teaching effectiveness.
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Angiostrongylus cantonensis is a parasitic nematode that needs to develop in different hosts in different larval stages. Freshwater snails, such as Pomacea canaliculata, are the intermediate host, and rats are the definitive host. Periodic shedding of the cuticle (moulting) is an important biological process for the survival and development of the parasite in the intermediate and definitive hosts. However, there are few studies on the cuticle alterations between different stages of this parasite. In this study, we observed the ultrastructural appearance and changes of the cuticle of the 2nd/3rd stage larvae (L2/L3) and the 3rd/4th stage larvae (L3/L4) using a scanning electron microscope. We also first divided L2/L3 into late L2 and early L3. The late L2 lacked alae, but possessed a pull-chain-like fissure. Irregular alignment of spherical particles on the cuticle were noted compared to the L3. Alae appeared in the early L3. The old cuticle turned into a thin film-like structure which adhered to the new cuticle, and spherical particles were seen regularly arranged on the surface of this structure. Regular rectangular cavities were found on the surface of L3/L4. The caudal structure of L3/L4 was much larger than that of L3, but caudal inflation, such as seen in L4, was not observed. These results are the first to reveal the ultrastructural changes of the cuticle of A. cantonensis before and after moulting of L2/L3 and L3/L4.
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Animals , Angiostrongylus cantonensis/physiology , Larva/physiology , Microscopy, Electron, Scanning , MoltingABSTRACT
Based on the concept of general education in higher education,Zhongshan school of medicine of Sun Yat-sen University launched general education course-‘ basic medicine introduction' to all non-medical undergraduates.Teaching contents,teaching methods and teaching effects of this course were explored and evaluated.By introducing basic medicine,the overall objective is to guide students to consciously maintain the mental and physical health and to stimulate students' thinking on the meaning of life.
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Objective To evaluate the protective effectiveness of intranasal immunizations with recombinated-pneumococcal autolysin(Re-LytA), which protects mice against local and systemic Streptococ- cus pneumoniae(Sp) infection. Methods Testing group (group A): CpG as an adjuvant, the mice were intranasally immunized with purified Re-LytA, obtained by affinity chromatograph. The negative control group(group B) were intranasally immunized with sterile saline. And the positive control group (group C) were received 23-valent polysaccharide commercial vaccine through intramuscular injection. All the samples were collected 2 weeks post the last immunization. The levels of antibody was determined by ELISA. Then the mice were challenged intraperitoneally and intranasally with Sp, respectively. The infection and coloniza- tion was followed by monitoring colony-forming units of Sp in the blood, homogenized lung, and nasopharyn- geal lavage fluid 4 days post intranasal immunization. The mice were observed daily to note the livability of each group. Results The level of the LytA antibody (IgG, IgA, slgA) in group A were higher than that in group B and C (P < 0.05). Neither the LytA nor polysaccharide antibody could be detected in group B. Polysaccharide antibody could be detected in group C. After challenged intraperitoneally there was no signifi- cant difference in survival rates between group A and group C (P > 0.05), which was significant higher than that in group B (P <0.05). After challenged intranasally, compared with the group A, the geometric mean colony-forming units washed from the nasopharyngeal lavage fluid of the group B and group C were signifi- cantly higher (P <0.05). Conclusion lntranasal immunizations with Re-LytA can protect mice against lo- cal and systemic pneumococcal infection, and the protective immunity may be related to sIgA.
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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.
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<p><b>OBJECTIVE</b>To rapidly and economically obtain knowledge about adult stage Schistosoma japonicum (Chinese strain) expressed genes using expressed sequence tag (EST).</p><p><b>METHODS</b>A directional cDNA library constructed from Schistosoma japonicum (Chinese strain) adult stage RNA was used to generate expressed sequence tags (ESTs). These were compared against an EMBL-parasites database and GENBANK database by BLASTn and BLASTx.</p><p><b>RESULTS</b>A total of 314 phage clones were randomly selected for generating expressed sequence tags (ESTs). From these clones, 132 EST-quality sequence were obtained. Among these EST-quality sequences, 113 ESTs were successfully submitted to the dbEST at GenBanK. A total of 7.6% of these EST-quality sequences were previously identified sequence of Schistosoma japonicum, while 4.5% were putatively identified sequences of Schistosoma japonicum. A total of 23.5% of these EST-quality sequences were putatively identified sequence of Schistosoma mansoni or other organisms. 57.6% had no matches in the database and were classified as unknown sequences. Most ESTs with the putative protein identified belonged to housekeeping proteins. Information about several interesting genes was found.</p><p><b>CONCLUSION</b>Partial cDNA sequencing to generate expressed sequence tags (ESTs) has the potential to rapidly and economically increase our knowledge about adult stage Schistosoma japonicum (Chinese strain) expressed genes.</p>
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Animals , Base Sequence , DNA, Complementary , Chemistry , Expressed Sequence Tags , Gene Library , Molecular Sequence Data , Schistosoma japonicum , GeneticsABSTRACT
Objective To obtain and characterize a novel gene of Schistosoma japonicum. Methods Looking for a novel gene through expressed sequence tags(EST),then predicting its function with the help of software on line. Finally the novel gene was cloned into an eukaryotic plasmid pEGFP N3. Results A novel gene with complete ORF was obtained. It has homogeneity with Defender Against Apoptotic Death 1 of human and pig. Conclusions EST is a good method to find new genes and analyse them with the help of software on line and characterize their function.
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Objectve To detect whether the CTP(phosphocholine cytidylyltransferase) gene was expressed in the asexual erythrocytic stages of Plasmodium falciparum (FCC 1/HN )by using the RT - PCR and to construct eukaryotic expression vector of CTP. Method The erythrocytic stage parasites of Plasmodium falciparum were cultured as described by Trager and Jensen. RNA from erythrocytic stage parasite was extracted by using Trizol reagent. The complete genes coding for CTP gene isolates FCCI/HN were amplified by reverse transcriptase -polymerase chain reaction(RT- PCR). CTP gene was cloned into eukaryotic expression vector pcDNA3. Results CTP encoding gene was amplified from the erythrocytic stages of Plasmodiumfalciparum (FCC 1/HN) and eukaryotic expression vector of CTP was constructed. Conclusion CTP gene was expressed in the erythrocytic stages of Plasmodium falciparum (FCC 1/HN) and eukaryotic expression vector of CTP was successfully constructed.
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Objective To clone the gene of autolysin(LytA) which are from different clinical strains of Streptococcus pneumoniae and express them in Escherichia coli. Methods The LytA gene was amplified by PCR from the total DNA of S.pneumoniae. Primers were designed according to the LytA gene sequence of R6. Recombinant plasmids were constructed and the sequences of different clinical strains were analyzed through method of bioinformatics. The cloned genes were expressed in E.coli and detected by SDS-PAGE. Results Complete LytA gene were amplified from all of the different clinical strains of S.pneumoniae and recombinant plasmids pGEX-4T-1-LytA were constructed successfully. After comparing the sequence of DNA and supposed protein, we find some differences. Induced by IPTG, LytA gene was expressed effectively in E.coli Jm109. Result of SDS-PAGE showed that the molecular weight of expressed protein was 62 kD, the same as calculated. Conclusions The sequences encoding LytA from different clinical strains of S.pneumoniae were cloned, the recombinant plasmids pGEX-4T-1-LytA was constructed successfully. Sequence analysis showed that there have difference among the gene and amino acid sequences of LytA from different clinical strains. Further studies should be focused on whether the difference contributes to activity of autolysin and the drug-resistance of S.pneumoniae.
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RNA interference (RNAi) is an effective antiviral mechanism of human body. It is a sequence specific process involving post transcriptional gene silencing initiated by double stranded RNA (dsRNA) homologous to the silenced genes. RNAi,as a genomic immune phenomenon involving the modulation of specific gene expression and an efficient gene-level defense mechanism against viral infection,has become the focus of study in biomedicine. This review summarized the researches of RNAi in inhibiting hepatitis virus infection,analyzed the advantages of RNAi in clinical treatment of hepatitis,and pointed out the existing problems,hoping to provide references for antiviral study of hepatitis infection.
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Objective To establish a rapid, specific and sensitive diagnostic technique for the human T. gondii infection with hematopoietic stem cell transplantation and discuss its clinical significance. Me- thods Fifty-six patients subject to hematopoietic stem cell transplantation were detected with ELISA and PCR. Results Among 56 recipients of hematopoietic stem cell transplantation, 7 were positive for T. gondii antigen and 10 were positive for SAG3 gene fragment respectively with the positive rate being 14.3 % and 17.8 % in the ELISA and PCR screening respectively. Twenty healthy people were negative for anti-Toxo antibody.Conclusion PCR is an accurate, relatively rapid, sensitive and specific method for detecting SAG3 gene of T. gondii, and can be considered a valuable additional tool for identification of T. gondii infections.
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After analyzing the correlation coefficient (r) of mid-clavicular liver size (MCL) and mid-sternal liver size (MSL), and the rate of correspond once between palpation and B Ultrasound of spleen, it was found that the "r" of MCL and MSL is 0. 6476 and 0. 5623 respectively, the correspond once rate of spleen is 76. 23%, This result shows that the examiner must master the palpation technique well and B Ultrasound should be used in the screening of schistosomiasis japonica if possible.
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Objective To construct a platform for in silico elongation and batch analysis of Schistosoma japonicum(Sj) ESTs, acquire the potential novel genes and research the expression profile of the genes. \ Methods\ On the basis of Linux operating system and local ESTs database of Sj, the BLAST and PHRAP softwares were used to construct a program to achieve the elongation of ESTs. Stand\|alone BLAST search against the nr database helped analyze the elongated sequence. After finishing the batch analysis script, the platform was used to research the Sj gene expression profile and acquire the potential novel genes. \ Results \ The platform showed satisfactory efficiency and fidelity. 487 elongated sequences obtained from 552 and 307 elongated sequences showed high homology within the nr database downloaded from NCBI. Furthermore, 104 elongated sequences displayed significant homology but showed no homology before elongated. 27 potential novel genes were filtered out. \ Conclusion \ An effective platform for Sj ESTs data mining was accomplished and further information on the potential novel genes was acquired.
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Objective To construct prokaryotic recombinant plasmids of transcriptional co-activator (TC) gene of Clonorchis sinensis, express and purify the recombinant protein and analyze its biological function. Methods A pair of primers was designed according to the known sequence of TC gene. The TC gene fragment was amplified by PCR. After purification and digestion with BamHⅠ and SalⅠ , the TC gene was connected to the prokaryotic expression vectors, pGEX-4T-1 and pET30a(+). By cloning target gene into these vectors, pGEX-4T-1 and pET30a(+), prokaryotic recombinant plasmids of TC gene were constructed and transferred into E.coli BL21. The positive expressed recombinants were detected by SDS-PAGE and Western blotting. Immobilized metal (Ni 2+ ) chelation affinity chromatography was used to purify His-TC produced by the expression of the recombinant protein pET30a(+)-TC. Results The recombinant plasmids, pGEX-4T-1-TC and pET30a(+)-TC, were constructed successfully. SDS-PAGE testified that the molecular weight of the recombinant protein was correct. Western blot analysis of GST-TC recombinant protein testified that the recombinant protein could be recognized by immunized rabbit serum, which means the protein is GST-immune active and the clone can express recombinant Clonorchis sinensis antigen. After affinity chromatography of the pET-TC protein, there was only one protein band with expected size on the SDS-PAGE gel. Conclusion The TC gene was screened from cDNA library of adult Clonorchis sinensis, cloned, expressed and purified. The purified protein of TC gene will be of importance for further research on the biological function of the gene.
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Objective To recognize and identify the arginase(ARG)gene of Schistosoma japonicum(Sj),and to study its protection potential as a vaccine.Methods The 5'-end of the ARG gene from the Sj cercariae cDNA library was amplified by nested-PCR and the sequence was identified by bioinformatics.The complete coding sequence(CDS)was cloned into pET30a(+)vector,and a recombinant SjARG protein(rSjARG)was expressed,purified and used to raise antibodies.ARG's activity as an enzyme was tested by ornithine-ninhydrin reaction.Western blotting was used to compare the immunologic characteristics of rSjARG with that of the native one in Sj adult worm.Indirect immunofluorescence assay was used to immunolocalize it.For evaluating the protection potential of rSjARG,mice were immunized by the recombinant protein and challenged by cercariae of S.japonicum.Results The CDS length of the SjARG novel gene was identified as 1095bp.rSjARG showed enzyme activity and the same immunologic characteristics with the native arginase in adult worm.SjARG located in the genital organ and gut of both sexes.The worm reduction rate and egg reduction rate in rSjARG group were 55.8% and 48.8% respectively,higher than that of the rSj26GST group(28.6% and 6.89% respectively).Conclusion SjARG gene was identified,which shows a higher protection than the Sj26GST.
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Objective To establish and maintain the life cycle of Clonorchis sinensis in laboratory.Methods Adult worms and eggs of Clonorchis sinensis were collected from naturally infected cats.Eggs were ingested by freshwater snails in aquarium.When the cercariae were released from infected snails, they invaded into freshwater fishes.From the 30th day on after the release of cercariae, the infection rate and metacercariae density in freshwater fishes were determined.Results After 95 days the infected snails began shedding cercariae in a temperature range of 24.3-37.2 ℃, and no cercariae were found under 20 ℃.The infection rate in the snails Parafossarulus striatulus and Alocinma longicornis was 12.5% and 18.0%, respectively.Metacercariae were found in fish at 30 days after cercariae infection, and matured metacercariae were detected in 45 days.The number of metacercariae per gram of fish meat in Pseudorasbora parva, Ctenopharyngodon idellus, Rhodeus sinensis, Hypophthalmichthys nobilis, Cirrhinus molitorella, Carassius auratus, Cyprinus carpio and Oreochromis niloticus was 1 792, 16, 8, 6, 5, 4, 4, and 2, respectively.Rats and cats were fed with metacercariae from fish to receive adult worms.Conclusion Life cycle of Clonorchis sinensis has been established and maintained in the laboratory.