Establishment of Experimental Model of Hepatic Schistosoma Japonicum Egg Granulomas in Mice

An experimental model of hepatic Schistosoma japonicum egg granuloma was established in C57BL/6 mice sensitized with soluble egg antigen(SEA) by direct injection of vital egg suspension into the spleen. The mice infected with cercariae of Schistosoma japonicum in abdominal skin were used for comparative studies. The results showed that morbidity of hepatic Schistosoma japonicum egg granulomas in the group sensitized with SEA was 100% and that the morphology, cellular constituents, developing process and the diameter and size of the egg granulomas in the group sensitized with SEA were similar to those of the group infected with cercariae. The authors suggest that this experimental model is a useful and appropriate tool for the study on egg granulomas of Schistosoma japonicum.

Effect of artemether on glyceraldehyde-3-phosphate dehydrogenase,phosphogly-cerate kinase,and pyruvate kinase of Schistosoma japonicum harbored in mice

目的：研究蒿甲醚（Ａｒｔ）对日本血吸虫３磷酸甘油醛脱氢酶（ＧＡＰＤＨ）、磷酸甘油酸激酶（ＰＧＫ）和丙酮酸激酶（ＰＫ）的影响．方法：小鼠感染血吸虫尾蚴３２－３８ｄ后ｉｇＡｒｔ１００－３００ｍｇ·ｋｇ－１，２４－７２ｈ后取虫测定上述３种酶和乳酸含量．结果：小鼠ｉｇＡｒｔ３００ｍｇ·ｋｇ－１后２４－４８ｈ，血吸虫♀、♂虫的ＰＧＫ和ＰＫ活力被抑制２７％－４８％；♀虫的ＧＡＰＤＨ对Ａｒｔ亦较敏感，♂虫则否．给药后７２ｈ，♀虫乳酸含量降低７２％，♂虫的降低４９％．结论：Ａｒｔ对血吸虫的ＰＧＫ和ＰＫ活力有明显抑制作用，♀虫的ＧＡＰＤＨ对Ａｒｔ亦较敏感。

Preventive effect of artemether in rabbits infected with Schistosoma japonicum cercariae

目的：观察蒿甲醚（Ａｒｔ）ｉｍ及其适宜给药方案预防血吸虫感染的效果．方法：兔感染日本血吸虫尾蚴后ｄ７－１５ｉｍ或ｉｇＡｒｔ观察几种给药方案的预防作用．结果：感染兔每周ｉｍＡｒｔ７５ｍｇ·ｋｇ－１１次，共３次，减♀虫率仅４２％．兔感染后ｄ７－１５ｉｇＡｒｔ１０－２０ｍｇ·ｋｇ－１，然后每７－１４ｄ给药１次，共２次，减♀虫率均在９１％以上；或ｉｇ１剂Ａｒｔ，继而每间隔７－１４ｄｉｇ１次，共３次，减♀虫率＞９４％；重复感染兔自首次感染后ｄ８每ｗｋｉｇＡｒｔ１次，共３次，或自首次感染后ｄ１４，每ｗｋｉｇＡｒｔ１次，共２次的减♀虫率为９５％－９７％．结论：本文所述几种给药方案对预防兔感染血吸虫尾蚴均有效果．

Effect of artemether on glucose uptake and glycogen content in Schistosoma japonicum

研究蒿甲醚（Ａｒｔ）对血吸虫摄入葡萄糖和糖原含量的影响．方法：用Ａｒｔ３００ｍｇ·ｋｇ－１ｉｇ治疗感染小鼠后２４－４８ｈ取虫，作体外培养，测定♀、♂虫糖原含量，对［Ｕ１４Ｃ］葡萄糖的摄入及［Ｕ１４Ｃ］葡萄糖掺入虫糖原的量．结果：感染小鼠用Ａｒｔ治疗后２４－４８ｈ取虫作体外培养１－２４ｈ，♂和♀虫的糖原含量分别减少２７％－６１％和３９％－７８％；６组♂虫中，仅３组的葡萄糖摄入减少２３％－３５％，而♀虫各组的均明显减少，减少率为１８％－３８％．除２组♂虫外，［Ｕ１４Ｃ］葡萄糖掺入虫的糖原量无明显变化．结论：Ａｒｔ引起血吸虫糖原的减少，可能与干扰糖酵解而不是与葡萄糖的摄入有关．

Exogenous bone morphogenetic protein-7 reduces hepatic fibrosis inSchistosoma japonicum-infected micevia transforming growth factor-β/Smad signaling

AIM: To investigate the antifibrotic effects of bone morphogenetic protein-7 (BMP-7) on Schistosoma japonicum (S. japonicum )-induced hepatic fibrosis in BALB/C mice. METHODS: Sixty BALB/C mice were randomly divided into three groups, including a control group (group A, n = 20), model group (group B, n = 20) and BMP-7 treated group (group C, n = 20). The mice in group B and group C were abdominally infected with S. japonicum cercariae to induce a schistosomal hepatic fibrosis model. The mice in group C were administered human recombinant BMP-7. Liver samples were extracted from mice sacrificed at 9 and 15 wk after modeling. Hepatic histopathological changes were assessed using Masson's staining. Transforming growth factor-beta 1 (TGF-β1), alpha-smooth muscle actin (α-SMA), phosphorylated Smad2/3 (pSmad2/3) and Smad7 protein levels and localization were measured by Western blotting and immunohistochemistry, respectively, and their mRNA expressions were detected by reverse transcriptionpolymerase chain reaction (RT-PCR). RESULTS: The schistosomal hepatic fibrosis mouse model was successfully established, as the livers of mice in group B and group C showed varying degrees of typical schistosomal hepatopathologic changes such as egg granuloma and collagen deposition. The degree of collagen deposition in group C was higher than that in group A (week 9: 22.95±6.66vs 2.02±0.76; week 15: 12.84±4.36 vs 1.74±0.80; P<0.05), but significantly lower than that in group B (week 9: 22.95±6.66 vs 34.43±6.96; week 15: 12.84±4.36 vs 18.90±5.07;P<0.05) at both time points. According to immunohistochemistry data, the expressions of α-SMA, TGF-β1 and pSmad2/3 protein in group C were higher than those in group A (α-SMA: week 9: 21.24±5.73 vs 0.33±0.20; week 15: 12.42±4.88 vs 0.34±0.27; TGF-β1: week 9: 37.00±13.74 vs 3.73±2.14; week 15: 16.71±9.80 vs 3.08±2.35; pSmad2/3: week 9: 12.92±4.81 vs 0.83±0.48; week 15: 7.87±4.09 vs 0.90±0.45; P<0.05), but significantly lower than those in group B (α-SMA: week 9: 21.24±5.73 vs 34.39±5.74; week 15: 12.42±4.88 vs 25.90±7.01; TGF-β1: week 9: 37.00±13.74 vs 55.66±14.88; week 15: 16.71±9.80 vs 37.10±12.51; pSmad2/3: week 9: 12.92±4.81 vs 19.41±6.87; week 15: 7.87±4.09vs 13.00±4.98;P<0.05) at both time points; the expression of Smad7 protein in group B was higher than that in group A and group C at week 9 (8.46±3.95 vs 1.00±0.40 and 8.46±3.95 vs 0.77±0.42; P<0.05), while there were no differences in Smad7 expression between the three groups at week 15 (1.09±0.38 vs 0.97±0.42 vs 0.89±0.39; P>0.05). Although minor discrepancies were observed, the results of RT-PCR and Western blotting were mainly consistentwith the immunohistochemical results. CONCLUSION: Exogenous BMP-7 significantly decreased the degree of hepatic fibrosis in both the acute and chronic stages of hepato-schistosomiasis, and the regulatory mechanism may involve the TGF-β/Smad signaling pathway.

A rapid one-step method of EIA for detection of circulating antigen of Schistosoma japonicum

Objective To establish a highly sensitive serologic method for detecting the circulating antigen of Schistosoma japonicum for the diagnosis of this disease and the evaluation of drug therapy effect.Methods A set of complex support made of poly vinyl chloride (PVC) film slide, adsorbed with specific antibody, was used to test serum samples collected from cases with schistosomiasis japonica, by adding specific enzyme conjugate and substrate tetra methyl benzidine (TMB) with 3% H 2O 2 in 10∶0.1, developed or prepared in our laboratory. Tests were carried out with the set on cases with malaria, paragonimiasis, clonorchiasis, visceral leishmaniasis and cysticercosis as well as normal individuals as control. Serum sample of 50 μl was used in each test and reacted with reagents at room temperature for 30 minutes. The color of positive reaction was blue while negative reaction was colorless.Results Positive rate among cases with schistosomiasis japonica was 100% (45/45) in acute stage, 94.8% (530/559) in early chronic stage and 52.4% (66/126) in late stage. False positive reaction was found neither among all normal individuals (0/513), nor among cases of 155 with malaria, 120 with clonorchiasis, 24 with visceral leishmaniasis and 110 with cysticercosis, except one among 29 cases with parasgonimiasis (1/29).Conclusions The rapid one step enzyme Immunoassay (EIA) to detect circulating schistosome antigen (CSA) has been well established in our laboratory with high sensitivity and good specificity as well as reproducibility. The reaction result can be read easily even in field conditions without power supply. Moreover, the assay is time saving, simple to handle and suitable for the diagnosis of shistosomiasis japonica and evaluation of drug therapeutic effect in practice in the control program of the disease.

Bioinformatics analysis of the structure and linear B-cell epitopes of aquaporin-3 from Schistosoma japonicum

Objective:To analyze the structure of aquaporins-3(AQP-3) from Schistosoma japonicum(SJAQP-3) using bioinformalical methods,and to provid of references for vaccine targets research.Methods:Protparam,BepiPred,TMHMM Server,MLRC,Geno3d,DNA star software packages were used to predict the physical and chemical properties,hydrophilicity plot, flexibility regions,antigenic index,surface probability plot,secondary structure,and tertiary structure of amino acid sequence of SJAQP-3.Results:SJAQP-3 had six transmembrane regions and two half-spanning helices that form a central channel.The half-spanning helices fold into the centre of the channel.Either of the half-spanning helix had a conserved motif of NPA common to all aquaporins.Predicted linear B-Cell epitopes were most likely at the N-terminal amino acid residues of Saa-7aa,59aa- 62aa,225aa-230aa,282aa -288aa,294aa -29Saa and 305aa -307aa area.59aa- 62aa,22Saa-230aa located outside the membrane,the others located inside the cell.Conclusions:SJAQP-3 is a integral membrane protein in Schistosoma japonicum tegument.There are six potential epitopes in SJ AQP-3.It might be a potential molecular target for the development of vaccines.

Osteopontin expression is associated with hepatopathologic changes in Schistosoma japonicum infected mice

AIM:To investigate osteopontin expression and its association with hepatopathologic changes in BALB/C mice infected with Schistosoma japonicum.METHODS:The schistosomal hepatopathologic mouse model was established by abdominal infection with schistosomal cercaria.Liver samples were obtained from mice sacrif iced at 6,8,10,14,and 18 wk after in-fection.Liver histopathological changes were observed with hematoxylin-eosin and Masson trichrome staining.The expression of osteopontin was determined with im-munohistochemistry,reverse transcription-polymerase chain reaction,and Western blotting.The expressionof α-smooth muscle actin(α-SMA)and transforming growth factor-β1(TGF-β1)were determined by im-munohistochemistry.Correlations of osteopontin ex-pression with other variables(α-SMA,TGF-β1,hepato-pathologic features including granuloma formation and degree of liver f ibrosis)were analyzed.RESULTS:Typical schistosomal hepatopathologic changes were induced in the animals.Dynamic changes in the expression of osteopontin were observed at week 6.The expression increased,peaked at week 10(P<0.01),and then gradually decreased.Positive correla-tions between osteopontin expression and α-SMA(r=0.720,P<0.01),TGF-β1(r=0.905,P <0.01),granu-loma formation(r=0.875,P<0.01),and degree of liver f ibrosis(r=0.858,P<0.01)were also observed.CONCLUSION:Osteopontin may play an important role in schistosomal hepatopathology and may promote granuloma formation and liver fi brosis through an un-explored mechanism.

The efficacy of NP11-4-derived immunotoxin scFv-artesunate in reducing hepatic fibrosis inducedby Schistosoma japonicum in mice

Schistosomiasis is one of the most prevalent parasitic diseases in China, and hepatic fibrosis caused by schistosome infection is the principal cause of death. The aim of this study was to evaluate the efficacy of NPll-4- derived immunotoxin scFv-artesunate on Schistosoma japonicum-induced hepatic fibrosis. A single-chain variable fragment （scFv） was generated from the murine anti-Schistosoma japonicum （S. japanicum） monoclonal antibody NP11-4. The scFv was expressed as a soluble protein and purified by Ni-affinity chromatography. After conjuga- tion with artesunate, the binding ability with soluble egg antigens （SEA） was determined by an enzyme-linked immunosorbent assay （ELISA）. The biological activity of purified scFv, scFv-artesunate （immunotoxin）, and artesunate was detected in vivo. Image-Pro Plus software was used to analyze the size of egg granuloma and the extent of liver fibrosis. The recombinant scFv expession vector was constructed and expressed successfully. After purification by a His-trap Ni-affinity column, the scFv yield was approximately 0.8 mg/L of culture medium. ELISA results showed that chemical conjugation did not affect the binding activity of the immunotoxin. Our animal experiments indicated that the immunotoxin could significantly reduce the size of egg granuloma in the liver and inhibit hepatic fibrosis. The immunotoxin could be used as a promising candidate in the targeted therapy of S. .japonicum-induced hepatic fibrosis.

Schistosoma japonicum attenuates dextran sodium sulfateinduced colitis in mice via reduction of endoplasmic reticulum stress

AIM To elucidate the impact of Schistosoma(S.) japonicum infection on inflammatory bowel disease by studying the effects of exposure to S. japonicum cercariae on dextran sodium sulfate(DSS)-induced colitis. METHODS Infection was percutaneously established with 20 ± 2 cercariae of S. japonicum, and colitis was induced by administration of 3% DSS at 4 wk post infection. Weight change, colon length, histological score(HS) and disease activity index(DAI) were evaluated. Inflammatory cytokines, such as IL-2, IL-10 and IFN-γ, were tested by a cytometric bead array and real-time quantitative polymerase chain reaction(RT-PCR). Protein and m RNA levels of IRE1α, IRE1β, GRP78, CHOP, P65, P-P65, P-IκBα and IκBα in colon tissues were examined by Western blot and RT-PCR, respectively. Terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling positive cells, cleaved-caspase 3 expression and Bcl2/Bax were investigated to assess the apoptosis in colon tissues.RESULTS Mice infected with S. japonicum cercariae were less susceptible to DSS. Mice infected with S. japonicum cercariae and treated with DSS showed decreased weight loss, longer colon, and lower HS and DAI compared with mice treated with DSS alone. A substantial decrease in Th1/Th2/Th17 response was observed after infection with S. japonicum. Endoplasmic reticulum(ER) stress and the nuclear factor-kappa B(NF-κB) pathway were reduced in mice infected with S. japonicum cercariae and treated with DSS, along with ameliorated celluar apoptosis, in contrast to mice treated with DSS alone. CONCLUSION Exposure to S. japonicum attenuated inflammatory response in a DSS-induced colitis model. In addition to the Th1/Th2/Th17 pathway and NF-κB pathway, ER stress was shown to be involved in mitigating inflammation and decreasing apoptosis. Thus, ER stress is a new aspect in elucidating the relationship between helminth infection and inflammatory bowel disease(IBD), which may offer new therapeutic methods for IBD.

Schistosoma japonicum ova maintains epithelial barrier function during experimental colitis

AIM:To evaluate the impacts of Schistosoma japoni-cum(S.japonicum) ova on the tight junction barriers in a trinitrobenzenesulfonic acid(TNBS)-induced colitis model.METHODS:Balb/c mice were randomly divided into three groups:control group;TNBS + ovagroup and TNBS + ova + group.TNBS was used intracolonic to in-duce colitis and mice of the TNBS + ova + group were pre-exposed to S.japonicum ova as a prophylactic intervention.Colon inflammation was quantified using following variables:mouse mortality,weight loss,co-lon extent and microscopic inflammation score.Serum expression of tumor necrosis factor-αand interferon-γ were assessed to evaluate the systemic inflamma-tory response.NOD2 and its mRNA were also tested.Bacterial translocations were tested by culturing blood and several tissues.ZO-1 and occludin were chosen as the representations of tight junction proteins.Both the proteins and mRNA were assessed.RESULTS:Ova pre-treatment contributed to the reliefof colitis and decreased the mortality of the models.NOD2 expression was significantly downregulated when pretreated with the ova.The TNBS injection caused a significant downregulation of ZO-1 and oc-cludin mRNA together with their proteins in the colon;ova pre-exposure reversed these alterations.Treat-ment with S.japonicum ova in the colitis model caused lower intestinal bacterial translocation frequency.CONCLUSION:S.japonicum ova can maintain epithelial barrier function through increasing tight junction pro-teins,thus causing less exposure of NOD2 to the lumi-nal antigens which may activate a series of inflamma-tory factors and induce colitis.

Immunological characteristics of natural resistance in Microtus fortis to infection with Schistosoma japonicum

Objective To explore the immunological characteristics of natural resis tance to Schistosoma japonicum infection in Microtus fortis (MF) living in the Dongting Lake area Methods Passive transfer of sera from uninfected laboratory bred MF (BM F) to albinao mice (AM) was performed to observe the acquired protection Sodiu m dodecyl sulfatepolyacrylamide gel electrophoresis (SDSPAGE) and enzymelin ked immunoblotting (ELIB) methods were used to recognize 4 different lifecycle stage antigens of S japonicum by sera from wild MF (WMF), BMF, BMFi3 and BMFi9 Tests were also performed on in vitro killing effect of sera and/or lymphocytes from BMF an d WMF to schistosomulae; quantitative determination of C3 and C4 by immuno turb idometry, and interleukin4 (IL4) and antibodies to the 4 stage antigens in s era from WMF, BMF and infected BMF by ELISA Results Compared with the control group, stool eggs per gram (EPG) of A M in the test group was significantly reduced by 8154%, miracidium hatching rate, by 5 0 67%, liver egg counts, by 7207%, the diameter of hepatic egg granuloma, by 7 0 39?m Western blotting probed with the 4 MF sera all revealed 7 specific ban d s for SSA, 3 for AWA and SEA, but none for CA antigens The sera and/or lymphoc yte s from WMF and BMF gave obvious killing effects on schistosomulae with an adjust ed death rate of 6412%-7883% The levels ofnatural antibodiesproduced b y MF to S japonicum were in the following order: antiSSA>antiAWA>antiS EA>an tiCA, all of which increased significantly after the infection Serum levels o f C3, C4 and IL4 in uninfected BMF were significantly higher than those in AM After infection, levels of C3 and C4 were further increased respective ly by 7283% and 29549% in the 4th week and IL4 by 30383% in the 9th day Conclusions Immunological characteristics of innate resistance in M f o rtis to S japonicum infection were existed with no significant difference betw een WMF and BMF

Orthotopic liver transplantation from a donor with Schistosoma japonicum

To the Editor：Despite of the rapid increase of donation after cardiac death （DCD） in China, the shortage of organs continues to be a major problem. Every organ procured is so valuable that it should never be discarded easily, especially a liver that could save a patient＇s life in an emergency. This leads to the use of grafts from donors with unrecognized Here and unusual diseases, including schistosomiasis. we reported a case of orthotopic liver transplantation （OLT） from a donor with Schistosorna japonicurn to a patient with end-stage cirrhosis due to HBV infection.

The Construction of Schistosoma Japonicum Vaccine BCG-Sj26GST and Its Identification

Summary: The expression of foreign gene, Schistosoma Japonicum 26 ku antigen (Sj26GST), in Bacillus Calmette Guerin (BCG), Mycobacterium ( M. smegmatis ) and Escherichia coli ( E. coli ) were studied. The cDNA fragment encoding Sj26GST was amplified by PCR using plasmid pGEX, which could express Sj26GST in E. coli as template. The Sj26GST cDNA was cloned into the downstream of human M. tuberculosis heat shock protein (hsp) 70 promoter with correct reading frame, and then the DNA fragment containing hsp70 promoter and Sj26GST gene were subcloned together into E. coli Mycobacteria shuttle plasmid pBCG 2000 to construct the expression shuttle plasmid pBCG Sj26. The recombinant BCG and M. smegmatis mc 2 155, which were electroplated with pBCG Sj26, could express Sj26GST and the recombinant Schistosoma Japonicum vaccine BCG Sj26GST was made. The recombinant Sj26GST (rSj26GST) were soluble and could be observed on SDS PAGE at molecular weight of 26 ku. The content of rSj26GST accounted for 15 % and 10 % of total bacterial protein in BCG and M. smegmatis respectively. The results of Western blot showed the combination of rSj26GST with antibody of GST.

Recombinant protein Schistosoma japonicum-derived molecule attenuates dextran sulfate sodium-induced colitis by inhibiting miRNA-217-5p to alleviate apoptosis

BACKGROUND Inflammatory bowel disease(IBD)affects millions of people worldwide and has emerged as a growing problem in industrialized nations.The lack of therapeutic targets has limited the treatment of IBD.Studies found that parasitic nematode infections can ameliorate clinical and experimental colitis.Our previous study found that rSj16,a 16-kDa secreted protein of Schistosoma japonicum produced by Escherichia coli,has protective effects on dextran sulfate sodium(DSS)-induced colitis in mice.Apoptosis is an important factor in the pathogenesis of colitis.However,it is not clear whether the effect of rSj16 on colitis is related to apoptosis.AIM To investigate whether the protective effects of rSj16 on colitis is related to apoptosis and its mechanism.METHODS In-vivo,colitis was induced by DSS.The severity of colitis was assessed.WB was used to detect the changes of apoptosis-related genes in colon tissues.Q-PCR was used to detect the changes of miRNA-217-5p and HNF1B.In-vitro,WB was used to detect the changes of apoptosis-related genes in intestinal epithelial cells.TUNNEL staining and flow cytometry were used to detect cell apoptosis.RESULTS rSj16 attenuates clinical activity in DSS-induced colitis mice.TUNNEL staining and WB results showed that apoptosis was increased in colon tissue after treatment with DSS,and the apoptosis of colon tissue was significantly reduced after treatment with rSj16.Compared with normal mice,the expression of miR-217-5p was increased in colon tissue of DSS-induced colitis mice.In addition,the miR-217-5p target gene hnf1b was decreased after administration of DSS.After treatment with rSj16,the expression of miR-217-5p was decreased and the expression of HNF1B was increased compared with the DSS-treated group.When Etoposide was used in combination with miR-217-5p mimic on MODE-K cells,the expression of cleaved-Caspase-3 and Bax was increased,and Bcl-2 was decreased compared with only Etoposide treatment,the expression of HNF1B was significantly reduced,suggesting that miR-217-5p acts as a pro-apoptotic in colon epithelial cells and down-regulates the target gene hnf1b.After rSj16 administration in MODE-K cells,miR-217-5p expression was significantly decreased,HNF1B expression was increased,and apoptosis was reduced.CONCLUSION The protective effects of rSj16 on colitis is related to apoptosis and miRNA-217-5p may be a further target for therapeutic intervention against IBD.

Perforation of small bowel caused by Schistosoma japonicum : A case report

A 67-year-old man from Jingzhou was admitted to the First Hospital Affiliated to Yangtze University in July 2013 with sudden onset of abdominal pain with dizziness for 12 h.The patient had sign of peritoneal irritation.Ultrasonography of the abdomen and pelvis showed hepatic fibrosis due to schistosomiasis.Computed tomography showed free gas in the peritoneal cavity.Plain abdominal radiography showed bilateral subdiaphragmatic accumulation of gas, perforation of the viscus, and radio-opacity in the left renal area.The patient underwent emergency exploratory laparotomy.At laparotomy, a moderate amount of muddy yellow pus was found in the intra-abdominal cavity.At the junction of the jejunum and ileum, about 250 cm from Treitz's ligament, there was an about 10-cm length of inflamed small bowel with perforation(3 mm in diameter) along the mesenteric border at the middle of the lesion.The patient underwent resection of the affected intestinal segment, along with end-to-end intestinal anastomosis.Histopathological examination revealed mucosal necrosis and hemorrhage with a large number of infiltrating eosinophils and neutrophils, and acute submucosal inflammation with a large number of infiltrating eosinophils and neutrophils associated with Schistosoma japonicum(S.japonicum) eggs.No intravascular adult parasite was found.Postoperatively, the patient was treated with praziquantel(30 mg/kg daily) for 4 d.The patient progressed well.To the best of our knowledge, this is the first case of small bowel perforation associated with eggs of S.japonicum.

Effect of artmether,hemin and Fe^(3+) on recombinant lactate dehydrogenase from Schistosoma japonicum

Objective:To explore antischitosome effects of artemether,hemin and Fe on S/LDH.Methods: Enzyme activity of rS/LDH was assayed in the standard reaction system by adding different concentration of reagents(0.00-0.10 mM artemether,0.00-0.02 mM hemin,0.00-0.50 mM Fe3+). Same solvents of the each reagent were used as control.Results:There was no enzyme activity inhibition observed at 0.10 mM artemther:obivious inhibition for lactate oxidation reaction and pyruvate reduction reaction were detected at 0.002 mM and 0.004 mM of hemin,respectively: comparing with that of the control（P【0.05）.The relative enzymatic activity inhibitions for pyruvate reduction reaction and lactate oxidation reaction at 0.02 mM hemin were 93.48%and 100.00%,respectively,comparing with that of the control（P【0.01）:both pyruvate reduction and lactate oxidation reaction were inhibited completely at 0.50 mM Fe3+,comparing with that of the control（P【0.01）.Conclusions:The results implied that SjLDH was not the direct molecular target of artemether.Hemin and Fe are inhibitors of SjLDH.

Studies on DNA Vaccine of the Conservative Region of Gene Encoding the Male-Specific Gynecophoral Canal Protein of Schistosoma japonicum (Chinese strain)

In order to observe the protective effect induced by vaccinating animals with the DNA vaccine of Sex-specific expression gene of Schistosoma, A 868 bp cDNA fragment amplified by RT-PCR from adult Schistosoma japonicum (Chinese strain) mRNA was cloned into the eukaryotic expression vector pcDNA3 and the recombinant eukaryotic expression vector pcDNA3-SjGCP1 was directly injected into BALB/c mice intramuscularly 3 times with the interval of 3 weeks .Both the vaccinated and control group of mice were challenged with 40 cercariae of Sj 5 weeks after last injection and perfused 7 weeks post-challenge. The worm and egg reduction rate got from vaccinated mice was 32.4% and 46.9% respectively. The result indicated that pcDNA3-SjGCP1 DNA vaccine induces the significant protection in animal against Schistosoma japonicum infection.