Table of Content

30 June 2006, Volume 24 Issue 3

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论著

Expression and Bioactivity of S1 scFv Antibody against SAG1 ofToxoplasma gondii Fused with Green Fluorescent Protein

SIJin;ZHUYin-chang;CAOLi-min;WANGXiao-ting;LIANGYou-sheng;GUANXiao-hong

2006, 24(3):  1-165. 

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Objective To construct, express and purify human scFv antibody （S1） against the recombinant SAG1 of Toxoplasma gondii and fused to green fluorescent protein （GFP）, and observe its binding capacity to tachyzoite of Toxoplasma gondii. Methods The GFP gene amplified from vector pEGFP-N1 was subcloned into procaryotic expression vector pET-26b（+）, then the S1 scFv antibody gene amplified from phagmid pIT-2-S1 was cloned into downstream of GFP gene. The recombinant plasmid pET-26b-GFPS1 proved by DNA sequencing was transformed into E.coli BL21, and induced for fusion expression of GFPS1 with IPTG, the green fluorescence of E.coli BL21 harboring plasmid pET-26b-GFPS1 was observed under the fluorescence microscope. The expressed GFPS1 was purified with Ni2+ chelating HiTrap HP column, and detected with SDS-PAGE. Toxoplasma tachyzoites were incubated with the recombinant GFPS1, and the binding bioactivity was observed under the fluorescence microscope. Results The fused gene of S1 and GFP was successfully cloned into procaryotic expression vector pET-26b proved by DNA sequencing. The green fluorescence of E.coli BL21 harboring plasmid pET-26b-GFPS1 was catched under the fluorescence microscope. The recombinant GFPS1 protein about Mr 53 000 was expressed in E.coli as inclusion body. The immunofluorescence detection verified that anti-rSAG1 scFv antibody S1 could specifically bind outer membrane of Toxoplasma tachyzoite. Conclusions The purified rGFPS1 shows a strong binding capacity to outer membrane of Toxoplasma tachyzoite using GFP as a labeling protein, and the constructed pET-26b-GFP can also be used for research on other targeting molecules.

Study on the Transmission of Toxoplasma gondii by Semen in Rabbits

LIUShi-guo;QINChuan;YAOZhi-jun;WANGDong

2006, 24(3):  2-170. 

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Objective To confirm the transmission of Toxoplasma gondii by semen and to investigate the impact of vaginal status on the transmission of T.gondii in female rabbits. Methods Sixteen male rabbits were infected with T.gondii by intraperitoneal injection each with 1×10⁵ RH tachyzoites. Eight rabbits died in 8-14 d after infection. Artificial vagina was used to collect semen from male rabbits weekly before and after infection for 8 weeks. If more than 2 portions of semen from 8 survived male rabbits were collected after infection， the collected semen was mixed weekly for later use. Twenty-seven female rabbits were divided into 4 groups： group 1 with normal vagina （7 rabbits）， group 2 with wounded vagina （7）， group 3 with trichomonas vaginｉｔis （7） and group 4 with colpomycosis infection （6）. Tachyzoites were found in mixed semen digested by trypsinase， and were used for endovaginal artificial insemination to female rabbits by uterine cavity tube once a week for 8 consecutive weeks. 2-3 d after every insemination， 2 ml blood was collected from helix vein of each rabbit， and stored at -40 ℃ for use. Anti-T. gondii antibody was examined by ELISA and the B1 gene of T.gondii was detected by PCR. Results Anti-T. gondii antibody was detected in some rabbits （2， 3， 1， and 1 rabbits from each of the groups respectively） on the 16th day after the first insemination. The positive rate of ELISA was 25.9%. The amplification of B1 gene （200 bp） by PCR appeared positive from the blood samples on the 3rd day after the first insemination and the last positive one was proved on the 51th day after the first insemination. Number of positive samples was 2， 1， 3 and 1 in the 4 groups respectively， with an overall PCR positive rate of 18.5%. Only 3 of the 27 rabbits were positive by both ELISA and PCR. Conclusions T.gondii can be transmitted by semen and the health status of vagina shows no impact on it.

Expression of Osteopontin in the Pericystic Layer of Hepatic Hydatid Cyst

LIJian-hui;PENGXin-yu;ZHOUZong-yao;WUXiang-wei;ZHANGShi-jie;NIUJian-hua;SUNHong

2006, 24(3):  3-174. 

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Objective To investigate the expression and distribution of osteopontin （OPN） in the pericystic layer of Echinococcos granulsus cyst. Methods 60 surgically excised cysts were studied with HE and immunohistochemistry staining by using antibodies specific for OPN. Immunofluorescence double labeling technique and Media Cybernetics Image （Pro Plus 5.1 software） were used to appraise the relationship between the OPN and macrophages （CD68）.Results Expression of OPN was found at various degree in hydatid cysts， 75% （45/60） was distributed in the intra-layer at the parasite side， 8.3% （5/60） distributed in the extra-layer near the side of liver parenchyma （“exocyst”-layer vs “adventitia”-layer, P＜0.01）. Macrophages were identified between the intra-layer and extra-layer， and OPN was observed in most of the macrophages. Meanwhile， OPN was concurrently found with the deposit of calcium in a similar distribution in the hydatid cyst. Conclusion Osteopontin mainly distributes in the intra-pericystic layer of hepatic hydatid cyst.

Protective Immunity Induced by Recombinant Schistosomajaponicum Thioredoxin in Mice

HANHai-bo;CAOJian-ping;LIUShu-xian;XUYu-xin;SHENYu-juan;LIXiao-hong;LUWei-yuan;LIUHai-peng;TANGLin-hua

2006, 24(3):  4-178. 

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Objective To investigate the protective immunity of the recombinant thioredoxin of Schistosoma japonicum（reSjcTrx）in mice. Methods Thirty 6-week old female C57BL/6 mice were randomly divided into 3 groups with 10 each: reSjcTrx with Montanide ISA720 adjuvant， adjuvant control， and infection control. Mice were vaccinated subcutaneously at week 0， 2， 4 with reSjcTrx emulsified in Montanide ISA720 adjuvant. The mice in adjuvant group was injected three times with Montanide ISA720 and saline only. Mice in infection control group were given no injection. Three weeks after final injection， each mouse was challenged with 30±1 cercariae of S. japonicum （Chinese strain）. At the week six after challenge， all mice were sacrificed and perfused. The number of recovered worms and eggs from liver tissue of mice were counted. Sera were collected from mice before immunization， before challenge and before killing. The anti-SjcTrx antibodies in sera were detected with ELISA. Results ELISA showed a high level of specific IgG antibodies in mice immunized with the reSjcTrx. The worm reduction rate and egg reduction rate of reSjcTrx immunization group were 22.8% and 29.5% respectively， significantly higher than those of the control groups （P﹤0.05）. SDS-PAGE and Western blotting revealed that the molecular weight of expressed protein was around Mr 14 000 and could be recognized by sera from rabbit infected with S.japonicum and from mice immunized with reSjcTrx. Conclusion The reSjcTrx induces certain protective immunity against schistosomiasis japonica in mice.

In Vitro Effect of Daphnetin on Cytochrome C Oxidase andRibonucleotide Reductase of Plasmodium falciparum

HUANGFang;TANGLin-hua;CHENBo;NIYi-chang;WANGQin-mei

2006, 24(3):  5-182. 

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Objective To test the in vitro effect of daphnetin on cytochrome C oxidase （COX） and ribonucleotide reductase （RNR） activity of Plasmodium falciparum. Methods P. falciparum （FCC1/HN） was cultured in vitro using the method of Trager and Jensen. The effect of daphnetin and daphnetin-Fe complex on COX and RNR activity of P.falciparum was tested by ultraviolet spectrophotometer and electron spin resonance （ESR） respectively. Result The parasites synchronized with sorbitol in vitro was treated by daphnetin and daphnetin-Fe complex. The inhibition level of the COX activity by daphnetin after being treated for 2， 4， 8 and 12 h were 0.6%， 73% and 80% respectively and the inhibition level by daphnetin at different concentrations （0.1， 1， 100 and 1mmol/L） for 6h was 3%， 31%， 53% and 84%， respectively. No considerable effect was observed on the COX activity of P.falciparum treated with daphnetin-Fe complex. The tyrosyl free radical was tested to reflect the RNR activity of P.falciparum at various times by ESR. The inhibition level by daphnetin for 1， 2， 3 and 4 h were 7%， 51%， 69% and 75% respectively， while the values treated by daphnetin-Fe complex were 8%， 6%， 11% and 9% respectively. The inhibition level by daphnetin at different concentrations （0.1， 1， 100 and 1 mmol/L） for 6 h was 3%， 31%， 58% and 93% respectively and while the values treated by daphnetin-Fe complex were 8%， 6%， 11% and 9%. Conclusion Daphnetin significantly reduces the COX and RNR activities of Plasmodium falciparum in vitro.

Biological Characteristics of the Korean Isolate KI-1 of Toxoplasma gondii

LINAi-fen;SHINEun-hee;PARKJae-hwan;HANEun-taek;CHAIJong-yil

2006, 24(3):  6-186. 

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Objective To study the biological characteristics of newly isolated Toxoplasma gondii Korean isolate-1 （KI-1）. Methods The morphology and infectivity of KI-1 were observed by transmission electron microscopy and animal inoculation. Both RH and KI-1 antigens were detected by an anti-T. gondii monoclonal antibody （mAb）, Tg563, and an anti-Neospora caninum mAb, 12B4. The genotype was determined by PCR-RFLP analysis of SAG2 locus. The sequence heterogeneity of the SAG1, ROP1 gene coding regions of the RH and KI-1 was detected by an automated sequencer. Results The morphology and infectivity of KI-1 were similar to those of RH strain. Both RH and KI-1 antigens reacted with Tg563, not with 12B4. In comparison to RH strain, the KI-1 showed a difference of seven positions of nucleotide substitutions and six positions of amino acid substitutions in both SAG1 and ROP1 gene coding regions. Conclusion KI-1 is an isolate of T. gondii with strong virulence. Compared with RH strain, certain genetic differences exist.

Impact of Blastocystis hominis Infection on Ultrastructure ofIntestinal Mucosa in Mice

ZHANGHong-wei;LIWen;YANQiu-ye;HELi-jun;SUYun-pu

2006, 24(3):  7-191. 

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Objective To observe the ultrastructural change of intestinal mucosa in mice infected with Blastocystis hominis, and to study the pathogenic mechanism of B.hominis infection. Methods 20 Kunming mice were randomly divided into 4 groups： group A treated with immunosuppressant （dexamethasone）, group B without immunosuppressant, group C as normal control and group D as immunosuppressant control. Groups A and B were then orally infected with 20⁴ cysts of B. hominis. Groups C and D were treated as control by infusing same volume of Locke′s solution. Six days after inoculation, mice in each group were killed and mucosa of ileocecum was observed by transmission electron microscope （TEM） and scanning electron microscope （SEM）. Results Under SEM, B. hominis located in enteric cavity and on the surface of ileocecum mucosa. Individual parasites also invaded into mucosa and its fold. Partial destruction of microvilli on the mucosa was observed. TEM observation indicated a reduction of microvilli on the surface of absorptive cells. Mitochondrial edema, rough endoplasmic reticulum dilatation and degranulation were found on absorptive cells and goblet cells. Lymphocyte infiltration and eosinophilia were found in intercellular stroma. Pathological changes in group A were more serious than that of group B. No abnormal change on the mucosal ultrastructure was found in groups C and D. Conclusions B. hominis infection causes significant ultrastructural lesion on the ileocecal mucosa in mice. Immune status of the mice can affect the degree of the lesion due to infection.

实验报道

Evaluation of Immunogenicity and Protection Efficacy of the Recombinant Hypoxanthine-Guanine-Xanthine of Plasmodium falciparum in Mice

XIAOJing-ying;ZHANGDong-mei;CAILian-shun;SHENLu-hui;PANWei-qing

2006, 24(3):  8-195. 

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Objective To investigate immunogenicity and protection efficacy of the recombinant hypoxanthine-guanine-xanthine （HGXPRT） of Plasmodium falciparum expressed in Pichia pastoris. Methods 35 BALB/c mice were divided randomly into five groups: HGXPRT+ISA720 experiment group, HGXPRT+Freund experiment group, ISA720 adjuvant control group, Freund adjuvant control group, and blank control group. BALB/c mice were subcutaneously immunized three times with the HGXPRT protein formulated by either Freund or ISA720 adjuvants at a three weeks interval. Mice were bled via tail vein at 2 weeks after each immunization. Specific antibodies were detected by ELISA as well as IFAT using cultured parasites. The immunized mice were challenged with 10⁵ P.yoelii 10 days after the third immunization and parasitemia was monitored daily by examining Giemsa-stained thin film. Results Strong immune response was induced by the HGXPRT antigen formulated with the adjuvant. Antibody titers of more than 1∶10⁵ were detected after the third immunization while no specific antibody was detected in the mice immunized with adjuvants only. The antibodies against HGXPRT recognized the cultured parasite by IFAT. Four days after mice were challenged with P.yoelii, high parasitemia appeared in the two control groups, which were 24 h earlier than experiment groups. The mean parasitemia of HGXPRT+ISA720 experiment group（29.3%） was significantly lower than that of control groups （70.0%） （P<0.05）. The mean parasitemia of HGXPRT+Freund experiment group （51.0%） was significantly lower than that of adjuvant control （60.7%） and blank control（70.0%） （P<0.05）. Conclusion HGXPRT of P.falciparum expressed in Pichia pastoris was highly immunogenic in mice. Antibody against the recombinant protein recognizes the cultured parasites, and immunization of mice with the recombinant protein provideｓ partial protection against the challenge of P. yoelii.

Identification of Recombinant Aldolase of Plasmodium falciparum and its Monoclonal Antibody Preparation

ZHANGRui-juan;ZHUHuai-min;ZHENGHui;NINGBei-fang

2006, 24(3):  9-199. 

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Objective To identify the recombinant aldolase （ALD） of Plasmodium falciparum， and to develop monoclonal antibodies （McAbs） against the recombinant ALD. Methods ALD gene was amplified by PCR from genomic DNA of FCC1/HN strain， and expressed in E.coli DH5α. BALB/c mice were immunized with the recombinant ALD of P. falciparum via celiac injection for 3 times with 2 weeks interval. Three days after a booster injection， spleen cells of the immunized mice were used for producing McAbs. The immune serum was tested by IFAT and Western blotting. Results BALB/c mice immunized with purified aldolase protein developed strong immune response to the antigen， and the titer of specific antibody reached 1∶10⁵ in all immune sera after the third immunization. Moreover， immune sera specifically recognized the cultured P. falciparum. Western blotting showed that the immune sera recognized specifically a Mr 41 000 band of crude malaria antigen. No cross-reaction with human red cells was detected. Seven positive hybridoma cell lines were obtained after 3 rows of selection. All the McAbs′ subclasses belong to IgG1. IFAT showed that only 4 McAbs could recognize the cultured P.falciparum. Conclusion Plasmodial aldolase has been successfully expressed and purified， and the established hybridoma cell lines can secrete McAbs specific to the aldolase of P. falciparum.

Study on the Molluscicidal Effect of META-Li Against Oncomelania hupensis

ZHUDan;ZHOUXiao-nong;ZHANGSi-qing;ZHANGGonghua;LIUHe-xiang;LUDa-bing;CAIGuo-ying;NIQuan-zheng;CAOZhi-guo;WUWei-duo

2006, 24(3):  10-203. 

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Objective To evaluate the molluscicidal effect of the META-Li（40% META liquid formulation） against Oncomelania snails in laboratory and field. Methods The experiment of META-Li against the snails by spraying， immersion and climbing-inhibition test was carried out in laboratory. Spray method was performed in the field to compare with the wettable powder of 50% niclosamide ethanolamine salt. Results In laboratory， the LC₅₀ of META-Li by spraying for 1， 2， 3 days was 0.78， 0.44 and 0.46 g/m² respectively； by immersion method for 1， 2， 3 days， it was 44.4, 27.4 and 24.8 mg/L respectively. When sprayed with active ingredient 2 g/m² of META-Li in the field， the snail death rate was above 90% after 7 days， similar to that of niclosamide. Conclusion META-Li shows high molluscicidal and climbing-inhibition effect on Oncomelania snails.

Development of a PCR Assay for Detecting Schistosoma japonicum-Infected Oncomelania hupensis

CHENJun-hu;WENLi-yong;ZHANGXu-zhao;ZHANGJian-feng;YULi-ling;HONGLin-di

2006, 24(3):  11-207. 

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Objective To establish a sensitive and specific PCR assay for detecting Schistosoma japonicum-infected Oncomelania hupensis. Methods Based on 18S-rRNA gene of S. japonicum， a PCR assay for detecting Onc-omelania snails infected with S. japonicum was established. The PCR product was sequenced， and the sensitivity， cross-reaction and mass detection experiments of PCR assay were performed. Results The location of PCR product for detecting Oncomelania snails infected with S. japonicum was similar to the target DNA， with a length of 469 bp and the same sequence as the target DNA. It was registered in GenBank （Accession No. DQ442999）. There was no PCR product for detecting uninfected snail. Experiments showed that the minimum DNA concentration of S. japoncium miracidium to be detected was 40 pg/μl. DNA from snail infected with single-tail cercaria could not be detected. The maximum dilution concentration of infected snail DNA pooled with uninfected snail DNA that could be detected was 1∶640. Conclusion The PCR assay for detecting S. japonicum-infected Oncomelania snails shows high sensitivity， specificity and effect of mass detection.

Cloning and Identification of ROP2 Gene of Toxoplasma gondii

WEIQing-kuan;ZHANGDian-bo;LIJin;LIGui-ping;WANGHong-fa;CUIYong;BAIXue-lian;FUBin;LIUYu-bing;ZAIDe-fu;HUANGBing-cheng;LIUKe-yi;HANGuang-dong

2006, 24(3):  12-211. 

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Objective To amplify ROP2 from the genomic DNA of Toxoplasma gondii RH strain and construct eukaryotic expression plasmid pc-DNA3-ROP2. Methods Tachyzoites of T. gondii RH strain were collected and depurated to obtain genome. A pair of primers was designed and synthesized according ROP2 gene sequence. The gene fragment encoding ROP2 was amplified from the genomic DNA of T. gondii RH strain by means of PCR. It was then reclaimed and purified， and inserted into cloning vector pUCm-T. The recon was cut by EcoRⅠ、 Hind Ⅲ， and the inserted ROP2 gene fragment was subcloned into pc-DNA3 eukaryotic expression vector using T4DNA ligase， followed by further PCR identi-fication， double digestion via restrictive enzymes， and sequencing. Results The amplified specific gene fragment of ROP2 was about 1.7 kb in length. The gene fragment cloned and subcloned into pc-DNA3 was correct， and the eukaryotic expression plasmid contained ROP2 gene fragment was successfully constructed. Conclusion The recombinant plasmid pc-DNA3-ROP2 was successfully constructed.

Cloning and Bio-informatics Analyｓis of the CsCrSP from Clonorchis sinensis

CHENShou-yi;LIJun-tao;XUJin;WEIQuan-de;XIEHong-yan;HUXu-chu;YUXin-bing

2006, 24(3):  13-214. 

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Objective To screen cDNA library from Clonorchis sinensis for gene identification， and to clone and construct library of secreted recombinant proteins. Methods cDNA library from Clonorchis sinensis was screened for identifying new genes by Blastn protocol， the sequence of which was further analyzed by Motifscan and NCBI Conserved Domain Search protocol. Results The secreted proteins （Pcs004f03） were identified， with a 689 bp DNA sequence （187aa）， and a theoretical molecular weight of Mr 21 100. It is predicted that the gene CsCrSP contains one N-glycosylation site， three N-myristoylation sites， three casein kinase II phosphorylation sites， one cAMP-and cGMP-dependent protein kinase phosphorylation site and protein kinase C phosphorylation site， a signal peptide at N-terminals and SCP-like extracellular protein domain. Conclusion The CsCrSP gene is a secretory cysteine-rich protein with a SCP-like extracellular protein domain.

Molecular Cloning and Characterization of a RRas HomologueGene from Trichomonas vaginalis

XUMing-yan;FUYu-cai;LIUJu-li;ZHANGRen-li

2006, 24(3):  14-218. 

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Objective To clone and characterize a RRas-like gene from Trichomonas vaginalis for studying cellular signal transduction pathways in the organism. Methods A cDNA clone， which showed homology with RRas proteins of human being， was isolated and sequenced from a cDNA expression library of T. vaginalis. The genomic DNA corresponding to the cDNA sequence was amplified using PCR technique and sequenced. Sequence analysis was per-formed using BLASTP， RPS-BLAST and ClustalW programs. Phylogenetic tree was constructed and bootstrapped with 1 050 replicates using the software MEGA3. Results The cDNA sequence showed a length of 705 bp with an open reading frame of 615 bp. The deduced amino acid sequence from the open reading frame possesses 205 residuals. Sequencing of the PCR product of genomic DNA revealed that the genomic DNA sequence encompassing the putative 5′-ATG and 3′-stop codons was identical to the cDNA sequence. Sequence analysis demonstrated that this gene was most homologous to the RRas members of Homo sapiens and Mus musculus （both having 51% identity and 70% similarity）， and the amino acid sequence contains highly conserved GTP-binding domains and a fully conserved effector domain of human RRas member. Phylogenetic analysis showed that TvRRas clustered with RAS oncoprotein branch and RRAS branch of human. Conclusion The encoding protein probably belongs to a RRas family of T. vaginalis.

Study on Methods for Isolation and Purification of Cryptosporidiumparvum Oocysts from Mouse Feces

CHENFu;HUANGKe-he

2006, 24(3):  15-222. 

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Objective To explore an applicable method for isolation and purification of Cryptosporidium parvum oocysts with high purity， recovery and vigor from mouse feces. Methods Four techniques were used for isolating and purifying C.parvum oocysts from mouse feces： modified saturated saline flotation， percoll gradient centrifugation， CsCl gradient centrifugation and the classical discontinuous sucrose gradient centrifugation. Oocysts received from the methods were used respectively to infect in vitro bovine fallopian tube epithelial cells （BFTE） and the development of the oocysts was examined under microscope after 48 h and 72 h cultivation. Results The number of oocysts received by the classical discontinuous sucrose gradient centrifugation [（2.86±0.08）×10⁷］ was significantly higher than that of percoll gradient centrifugation [（1.52±0.08）×10⁷］ （P<0.01） and CsCl gradient centrifugation [（2.46±0.13）×10⁷］ （P<0.05）， but similar to that of the modified saturated saline flotation [（2.88±0.15）×10⁷］. No significant difference was found on the number of oocysts by BFTE cultivation at 48 and 72 hours post-inoculation（P>0.05）. Oocysts received from CsCl gradient centrifugation showed higher purity than those by discontinuous sucrose gradient centrifugation. Conclusion In comparison to the classical discontinuous sucrose gradient centrifugation, operation of the modified saturated saline flotation is easier and faster， and the purity of oocysts isolated by CsCl gradient centrifugation is higher.

In Vitro Detection of Immune Sera to Plasmodium falciparumChimeric Protein-2.9 for Inhibition of Parasite Ｇrowth by LDH Method

QULi;PANWei-qing

2006, 24(3):  16-225. 

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Objective To investigate the in vitro inhibition effect of the rabbit serum immunized with P.falciparum chimeric protein on the parasites by lactate dehydrogenase （LDH） method. Methods Sera of rabbits immunized with P.falciparum chimeric protein were used as test sample， with an initial parasitemia of (0.4±0.1)% and 2% hematocrit suspension. After 40-42 h of cultivation, LDH assay and a traditional microscopical method were applied to obtain the parasite inhibition rate and infection rate of erythrocytes. Results Sera of rabbits immunized with the protein showed a strong in vitro inhibition effect on P.falciparum. There was no significant difference of inhibition rates detected by the two methods (97% and 100% respectively) （P>0.05）. Conclusion The LDH method applied in the in vitro inhibition assay for P. falciparum seems simple, reliable and has generated a satisfactory result.

防治经验

Malaria Situation and Evaluation on the Control Effect in Henan Province during 1990-2005

LIUXue-zhou;XUBian-li

2006, 24(3):  17-229. 

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Objective To analyze malaria situation and evaluate the effect of control program in Henan Province during 1990-2005. Methods Data were collected and analyzed on the measures and effects of malaria control, vector surveillance, blood examination for cases with fever and serological surveillance in the province during 1990-2005. Results In the 16 years, a total of 802 700 people were given pre-transmission season treatment with chloroquine and primaquine for a radical cure of vivax malaria, chemoprophylaxis was given to 764 300 people at high risk during the transmission season, treatment or presumptive treatment was given to 43 891 cases. 11 216 100 cases with fever were tested and 11 213 （0.10%） were found positive accounting for 29.01% （11 213/338 654） of all malaria cases. A total of 1 332 800 bed nets were treated with insecticide and 1 999 300 people were protected in 1990-1992 and 1996-1999. 34 846 residents including pupils were tested with IFAT in 1990-2000 and 1149 （3.30%） were positive. The parasite rate amongst 71 234 local residents including pupils was 0.40% （286/71 234）. The principal transmitting vectors were Anopheles sinensis and An.anthropophagus. The man-biting habit for An. sinensis and An.anthropophagus was 0.060 8 and 0.314 3 respectively, and the vectorial capacity of An.anthropophagus was 22.4 times higher than that of An.sinensis. In this period, 38 654 malaria cases were reported in the province and the annual malaria incidence was 2.62 per hundred thousand, the lowest annual incidence was in 1992 （0.37 per hundred thousand）. 70.05% （27 076/38 654） of these malaria cases were from areas where An. anthropophagus was present. Conclusions In general, the malaria control activities have been effective and the epidemiological situation kept stable in Henan Province, although in some areas the situation is unstable and outbreak spots or focal epidemics occur.

现场研究

Validity of Inquiry in Screening Chronic Schistosomiasis japonica

JIATie-wu;ZHOUXiao-nong;WANGXian-hong;WUXiao-hua;YIPing;XUYong-an;HEWei-long;HELing-yong

2006, 24(3):  18-235. 

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Objective To study the indicators and validity of inquiry in the screening of chronic schistosomiasis japonica. Methods 51 villages of Hanshou county were selected at random in Hunan Province and the whole resident (>6 months/year) population aged 5 years and above was eligible for inclusion in the study。 Inquiry through questionnairing， serological test （ELISA） and B type ultrasonography were applied respectively to screen chronic cases and evaluate morbidity due to schistosome infection. Logistic analysis was performed to explore the relationship between indicators of questionnaire and the results of ELISA and abdominal ultrasonography. Bayes discriminant analysis was used to assess consistency of inquiry and ELISA， inquiry and the degree of hepatic fibrosis. Results 26 426 inhabitants in the endemic villages were screened by ELISA with 1 380 （5.2%） positive. 1 264 sero-positive and 1 446 sero-negative cases were asked questions relating to schistosomiasis and examined by abdominal ultrasonography. Inquiry indices such as self-reported diarrhea， stool with mucus and fatigue during the last two weeks， history of infested water contact and times of treatment were specific to chronic schistosomiasis. The coincident rate for validation was 75.9% between inquiry and ELISA， and 75.4% between inquiry and hepatic fibrosis degree. Conclusion Validity of inquiry was satisfactory in screening chronic schistosomiasis in endemic areas.

Impact of the Three Gorges Dam Construction on Transmission of Schistosomiasis in the Reservoir Area

ZHANGHui-juan, GUOJia-gang

2006, 24(3):  19-240. 

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Possible impact of ecological and social environmental changes due to the construction of the Three Gorges Dam on the transmission of schistosomiasis draws great attention of the health authority and publics. This article reviews the situation and progress of research on schistosomiasis transmission in reservoir area from three aspects: the possibility of snail spreading and breeding， imported infection sources and social behavioral factors of the people.

论文

Analysis on Theses and Citation of the 《Chinese Journal of Parasitology and Parasitic Diseases》 in 2004-2005

SHENGHui-feng;FUXiu-lan;BOWei;HUYa-qing;DAIJing

2006, 24(3):  20-III. 

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The published articles and citation of the Chinese Journal of Parasitology and Parasitic Diseases in 2004-2005 were statistically analyzed. Among 312 papers published in the two years, original articles and experiment reports occupied 42.3% and 7.7% respectively. Authors were mainly from colleges/universities (61.5%) and institutions for disease control (28.5%). 51.9% of the articles received support by research funds/foundations. 82.3% were with reference citation mostly from periodicals, with 58.7% and 31.5% respectively from international and national (Chinese) journals. The average Price index was 44.9%. This Journal possesses a group of stable and qualified authors, covers substantial content with relatively broad citation, and is an important source of information in parasitological research.

研究简报

Construction of Prokaryotic Expression Vector for Trichomonas vaginalis Silent Information Regulator 2 and Its Expression

ZHANGKe-hao;HUANGLi-xia;FUYu-cai;ZHANGJia-xin

2006, 24(3):  21-VI. 

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Total RNA was isolated from Trichomonas vaginalis and Tv-Sir2-like cDNA was amplified by RT-PCR and cloned into pGEM-T Easy plasmid. A fragment of Tv-Sir2-like cDNA was subcloned into the expression vector pET-41b and expressed in E.coli BL21 with induction of IPTG. The full-length of Tv-Sir2-like cDNA was cloned and sequenced. The prokaryotic expression system of pET-41b/Tv-Sir2-like was constructed. The fusion protein of Tv-Sir2-like was expressed in E.coli BL21，occupying 30% of the total bacterial protein after being induced by IPTG for 5 h. SDS-PAGE analysis showed that the fusion protein was about Mr 59 000. The recombinant protein of Tv-Sir2-like is efficiently expressed in E.coli BL21.

Observation on Polytene Chromosomes of the Ovarian NurseCell of Anopheles minimus from Yuanjiang

SHIHuan?-huan;HUANGJie-gang;TIANChun-lin;YUANZhi-gang

2006, 24(3):  22-203. 

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Anopheles minimus collected from Yuanjiang, Yunnan Province, were bred with standard methods in lab. The ovarian nurse cells of A.minimus were separated and stained, and the whole polytene chromosomes were photographed under light microscope and compared with A.minimus from Guangxi. 365 samples of ovarian nurse cells were observed. The chromosomes included one telocentric sex-chromosome X, two submetacentric autosomes II（autosome II right arm, 2R and autosome II left arm, 2L） and two metacentric autosomes III（autosome III right arm, 3R， and autosome III left arm, 3L）. The X is the shortest chromosome and the 2R is the longest one. In comparison with the pattern of polytene chromosomes of A. minimus from Guangxi, difference at 12 positions has been found at the parts of arms in banding sequences.