Table of Content

30 December 2004, Volume 22 Issue 6

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论著

Distribution of Inducible Nitric Oxide Synthase in Different Stages of Schistosoma japonicum

LONGXiao-chun;LIUWen-qi*;LIYong-long;AndreasRupple

2004, 22(6):  1-323. 

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　Objective To study the presence of iNOS in Schistosoma japonicum and demonstrate its distribution in different stages of this schistosome. Methods Cryostat sections for adult worms and paraffin sections for eggs in the liver of infected mouse, sporocysts and cercariae in snails were prepared, immunofluorescent test was performed to detect the presence of iNOS in adult worms, sporocysts, cercariae and miracidium, the distribution of this enzyme was observed in different stages of Schistosoma japonicum. Western blotting was used to further demonstrate the immunoreactivity to iNOS in adult worms. Results The results of immunofluorescent test showed that specific yellow- green fluorescence was mainly among subtugment of adult worms. Positive staining was also distributed on the surface of miracidium and its glands. For both sporocysts and cercariae, the majority of fluorescence was on their surface. Anti-iNOS antibody could recognize an apparent specific band in Western blotting of adult worm proteins, with a of Mr 210 000. Conclusion There is an expression of iNOS-like enzyme in Schistosoma japonicum.


A Sampling Survey on the Distribution of Oncomelania Snails in Zhejiang Province

WENLi-yong;ZHENGWei;ZHUMing-dong;YANDe-hua;YANGJi-shun;GAOLu-lu;CHENJun-hu;ZHANGJian-feng;YULi-ling;LINLi-jun;TAOHai-quan

2004, 22(6):  2-327. 

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　Objective To find out current distribution of Oncomelania snails and Schistosoma infection in snails in Zhejiang Province, so as to improve the project of schistosomiasis control. Methods Investigation spots were selected by stratified cluster sampling method, 100 villages of 34 counties were selected from 7 106 villages of 55 counties as survey spots. Synchronously systematic and environmental samplings were used for the survey. Snails were dissected to determine the infection status and spots with sham snails were set to assess the quality of the survey. Results The result showed that snails were found in 223 strips, 1 572 frames and 73 300 m 2 area in 32 villages of 21 counties. Snails were found in an area covering 72 640 m 2 in 29 villages of 18 counties in hilly region, which accounted for 99.1% of total snail habitats. The significantly larger area with snails was revealed in hilly region than that in water network region (t=3.04, P<0.01). 1 st, 2 nd strata occupied 71 680 m 2 snail area, which accounted for 97.8% of total snail area, much higher than that in the 3 rd stratum (t=3.71, P<0.01). Snail habitats in the irrigation ditches and canals accounted for 62.6% of total snail area, significantly higher than that of farmland (t=3.02, P<0.01). No snails were found infected among 7 892 living snails by dissection. The theory value of snail area in Zhejiang Province was 1 361 940 m 2. Conclusion It is estimated that the snail-ridden area is about 1 500 000-2 000 000 m 2in the Province, mostly found in the villages of hilly region with a record of snail habitats during the recent 4 years and the primary environment of the snail areas were ditches and canals. No infected snails were found from the survey.


In Vitro Effect of Cyclosporine A on Juvenile Schistosoma mansoni Labeled by AF18 (5-N-octadecanoyl aminofluorescin)

LIUJian-fa;JohnRKusel

2004, 22(6):  3-330. 

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　Objective To explore the in vitro effect of cyclosporine A on the tegument of juvenile Schistosoma mansoni labeled by AF18 and investigate the effect of cyclosporine A on schistosomula surface membrane fluidity. Methods Preparation of transformed schistosomula, adding cyclosporine A into tubes containing schistosomula and labeling of transformed schistosomula with AF18,then observe schistosomula under fluorescence microscope. Results Schistosomula of different groups labeled by AF 18 were damaged by cyclosporine A in vitro. Conclusion Cyclosporine A increases the uptake of AF18 by schistsomula in vitro which is dose-dependent, and decreases the parasite surface membrane fluidity.


The Survey of Cryptosporidium Infection Among Young Children in Kindergartens in Anhui Province

LUJun;LIChao-pin

2004, 22(6):  4-333. 

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　Objective To study the cryptosporidiosis infection among young children in 29 kindergartens in the province, and to explore the best way to diagnose the infection. Methods Stool specimens of 1 204 children were collected, oocysts of Cryptosporidium were identified with auarmine O-modified staining, acid-fast staining, safranine T and methylene blue staining, and auarmine O-modeified acid-fast staining. Results The detection rate of Cryptosporidium in four stainings were 2.46%,1.50%,1.98% and 3.46% respectively, and the rate was significantly higher by auarmine O-modified acid-fast staining than other stainings (P<0.01). The infection rate was significantly lower in urban children (2.14%, 15/684) than the rural ones (5.19%, 27/520). Boys and girls showed similar detection rate (1.99%, 24/1 204 vs 1.50%, 18/1 204). Cryptosporidium infection was usually subclinical, the major clinical features of cryptosporidium included benign doiarrhea, mild abdominal pain and nausea. Conclusion The Cryptosporidium infection was relatively common in kindergartens in Anhui and higher infection rate was found in rural children. As majority of the Cryptosporidium infections are subclinical, the confirmation of diagnosis is important though difficult.


Immunoprotection Induced by Recombinant Plasmids pVAX1-Mzp5-7 of Eimeria tenella

QINRui-ling;ZHANGXi-chen;LIJian-hua;XUZhan-yun;YINJi-gang;YANGJu

2004, 22(6):  5-337. 

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　Objective To observe the immunoprotection of recombinant plasmids of λMzp5-7 to chicken challenged with Eimeria tenella(E.t) oocysts. Methords All the chicken were immunized with the recombinant plasmids by different inoculation pathways, three times on d7, d14 and d21, and challenged with E.t oocysts. The response of specific humoral and cell immunity were detected by the immunological methods such as the specific antibody response, the ratio of CD4+/CD8+ T cells. Results The results showed that the recombinant plasmids can induce immune response. The specific immune responses were strengthened with the increase of immunization times. The difference of the immunity indexes among experiment groups was not significant, while the ratio of CD4+/CD8+ T cells and antibody titer were significantly higher in experiment groups than those in the control groups. The number of oocysts shed in experiment groups decreased and the shedding duration was shorter significantly. The body weight of the chicken in experiment groups increased significantly and the lesion in cecum was slighter than that of control groups. Conclusion The recombinant plasmids of λMzp5-7 show an immunoprotection to chicken challenged with E.t oocysts.


The Effect of Sandfly Control on the Transmission of Visceral Leishmaniasis

JINChang-fa;HESheng-quan;HONGYu-mei;LIGuo-ru

2004, 22(6):  6-339. 

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　Objective To observe the effect of Phlebotomus chinensis control including insecticide residual spraying in the habitats and bathing for dogs on the transmission of visceral leishmaniasis in Nanping of Sichuan Province. Methods Alphamethrin with a dosage of 50 mg/m2 was sprayed in the wild caves and 2.5% deltamethrin wettable power at a concentration of 250 mg/L was applied for dog bathing in the villages. The density of sandflies in the natural caves was examined and data on the incidence of visceral leishmaniasis were collected from epidemiological survey following the sandfly control measures. Results The density of sandflies has been considerably reduced after the chemical spraying in caves, the important habitats of the sandflies. By both the cave spraying and bathing for dogs since 1993, the reported human cases of laishmaniasis also decreased. Conclusion Measures for sandfly control including insecticide spraying in the habitats and bathing for dogs with insecticide solution can significantly reduce the sandfly density, and can contain the transmission of visceral leishmaniasis in the endemic area.


Influence of InterferonγTreatment on Expression of TGF-β1 and Its Receptors in Liver Fibrosis of Mice with Schistosomiasis japonica

ZHANGBin-bin;JIAOYang-wen;CAIWei-min;TAOJun;LIURong-hua

2004, 22(6):  7-343. 

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　Objective To investigate the effect of interferon-γ(IFN-γ)on the expression of TGF-β1 and its two membrane receptors - TGF-β receptor I(TβRI), TGF-β receptor II(TβRII), and observe the expression of TGF-β1, TβRI and TβRII during the development of liver fibrosis in BALB/c mice infected by Schistosoma japonicum. Methods BALB/c mice, aged 6-8 weeks, were infected with cercariae of S. japonicum. The infected mice were divided randomly into three groups 16 week after infection:model group,praziquantel group and praziquantel combined with IFN-γ group. Liver specimen were obtained at 8, 12, 16 week and at the end of treatment. Pathological examination, immunohistochemistry and RT-PCR were used to evaluate the pathological change, the expression of TGFβ1, TβRI and TβRII and the mRNA level respectively. Results The expression of TGF-β1, TβRI, and TβRII can be detected in infected mice, while the expression around egg granulomas enhanced along with the progress of the disease. With the therapy of IFN-γ, the reduction of egg granulomas, and of the expression of TGF-β1, TβRI and TβRII was observed. From the transcription level, it was found that TGF-β1 mRNA increased at 12 week and peaked at model group, then decreased to the normal level after treatment with IFN-γ combined with praziquantel. The level of TβRII mRNA reduced at 8 and 16 week and returned to normal at the end of treatment. More interestingly, TβRI mRNA remained at the normal level on the whole course both in the development of fibrogenesis and the period of treatment. Conclusion The up regulation of TGFβ1 and down regulation of TβRII mRNA may induce liver fibrogenesis and IFN-γ might suppress TGFβ1 to reverse fibrosis. The mechanism of the suppression is mediated by down regulation of expression of its two receptors at protein level but not by influencing the mRNA expression.


Effect of Sodium Citrate Based Anticoagulants on the Growth Activity of Malaria Parasites

LIUZhong-xiang;WANGXian-feng;LIShu-mei;LIXun;XUECai-fang;MIAOJun*

2004, 22(6):  8-348. 

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　Objective To study the effect of anticoagulants based on sodium citrate on the growth activity of malaria parasites. Methods The parasites were treated with 3 anticoagulants (ACD, CD and SC), respectively, and the parasitemia was determined to measure the effect of the anticoagulants on the growth of the parasites. Unsynchronized Plasmodium falciparum was treated with the anticoagulants at different concentrations for 3h at 37℃. Treated erythrocytes were mixed with normal parasites or treated parasites with normal erythrocytes, which was followed by parasitemia determination of the two cultures to determine the cell target of the anticoagulants. Stage-synchronized parasites (ring, trophozoite and schizont) were treated as above to investigate the stage target. P.berghei was also treated with anticoagulants and inoculated in mice to detect the effect of anticoagulants on the animal malaria parasite by counting the parasitemia. Results all 3 anticoagulants inhibited falciparum parasite growth and ACD had the strongest potency. The treatments of the erythrocyte and the parasite with anticoagulants respectively showed that the anticoagulants targeted the parasites rather than normal erythrocytes. Stage-synchronized parasite treatment suggested anticoagulants primarily inhibited schizonts. The effect of anticoagulants on P.berghei was similar to that on P.falciparum. Conclusion ACD showed the most significant inhibitive effect on the growth of malaria parasites and SC was the best anticoagulant based on sodium citrate for malarial experiments.


Preliminary Study on the Ecology of Trichobilharzia Cercariae in the Huaihe River System

SHENGSi-chun;QINZhi-hui;ZHANGMin-qun;TAIYan;NIShi-gang;WENJi-yue

2004, 22(6):  9-352. 

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　Objective To investigate the ecological habit and characteristics of Trichobilharzia cercariae in the Huaihe river system. Methods During June of 2002-May of 2003, Radix auricularia snails were collected monthly in Yaohe Fishery of the branch of the Huaihe River. The cercariae, released from the positive snails and collected by Shade Drop Bottle, were examined by direct press. Ducklings were infected by cercariae with different ages and examined for the infection by miracidia hatching method.Results The results showed a typical seasonal fluctuation in infection rate of the snails, i.e. the cercariae detection rate was 0.81% in July, 0.65% in June, 0.07%-0.26% in April, May, August, September and October respectively, with a significant difference (χ 2=26.73, P<0.01). The release of cercariae from the snails showed a diurnal pattern in the natural conditions, with a significant peak between 8:00-12:00. It was proven that the main factors affecting the emerging of cercariae were temperature and light. The cercariae showed positively phototaxis. It was also showed that 50% mortality of the newly released cercariae between 18-25℃ occurred at 41h, and all cercariae died within 52h. The infectivity of cercariae was age-dependent. Under 18-25℃, the highest infectivity was found at 0.5-8h after emergence, then declined steadily to negative by 40 h post-emergence. Conclusion The ecological characteristics of Trichobilharzia cercariae have been preliminarily verified in the Huaihe river system.


Study on Surface Adhesion Protein 33 Gene Sequence of Different Trichomonas vaginalis Isolates

YUANLi-jie;GAOXing-zheng

2004, 22(6):  10-356. 

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　Objective To study genetic polymorphism of surface adhesion protein 33 (AP33) gene on the seven isolates of Trichomonas vaginalis. Methods PCR technique was performed to amplify AP33 gene from the seven isolates, DNA sequences were obtained from the AP33 gene of the isolates and phylogenetic tree was built. Minimal lethal concentrations(MLC) of metronidazole on the isolates were measured in vitro. Results Percentage of the similarity between 7 isolates and U87098 in GenBank was 98.2%-100%,which indicated a high homology and belonged to isotype isolates. There were four branches between Beijing 1 isolate and Tangshan isolate, Jiujiang 1 isolate and Jiujiang 2 isolate, Beijing 2 isolate and Jiujiang 3 isolate, Chengde isolate and U87098 isolate in phylogenetic tree, which showed a close genetic relationship respectively. No relativity was detected between geographical origin and genetic relationship. Conclusion There is a close genetic relationship among the seven T. vaginalis isolates. MLC showed a difference between isolates which have close relationship.


实验报道

The Experimental Study of Garlicin in Treating Pneumocystis carinii Pneumonia in Rats

LUZhi-min;TANGHong-wei;ZHANGZhen-ming;LIUJin-hua;ZNANGJin-shun;ZHANGWei-zhen

2004, 22(6):  11-360. 

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　Objective To assess the therapeutic effect of garlicin on Pneumocystis carinii pneumonia (PCP) of immuosuppressed rats. Methods The Wistar rats were injected intramuscularly continually with dexamethasone for eight weeks to establish the rat model of PCP. The rats were treated with garlicin, meanwhile control groups without treatment and with SMZ-TMP treatment were established respectively in PCP model. The efficacy was evaluated based on the lung weight, lung /body weight ratio and mean cyst number per 100 fields in lung print smear. Results The mean lung weight of the rats in garlicin is 1.73±0.17, lung/body weight ratio is 0.84±0.12, they are obvious lower than 2.31±0.35 and 1.25±0.35 of control (P<0.01). The numbers of cysts in lung print smear is reduced 62.9% compared with control. The results is similar to that with SMZ-TMP. Conclusion Garlicin shows an obvious therapeutic effect on Pneumocystis carinii pneumonia in rats with an efficacy similar to that with SMZ-TMP.


Change of Cytokines in Mice with Echinococcus multilocularis Infection

WEIXiao-li;DINGJian-bing;XUYan;WENHao;LINRen-yong

2004, 22(6):  12-364. 

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　Objective To observe the change of six cytokines in mice infected with Echinococcus multilocularis as part of the study on immunological mechanism in the infection. Methods Mice were infected by abdominal inoculation of echinococcus protoscoleces. The change of serum level of the cytokines IL-2、IFN-γ、TNF-α、IL-4、 IL-5 and IL-10 was determined by ELISA during the infection which lasted for 260 d. Results Compared with uninfected control, the levels of the cytokines all significantly increased in the 260 d. The level of IL-2 reached a peak after 80 d post-infection (p.i.), then decreased quickly after 140 d p.i., High level of TNF-α was detected after 40 d, compared to uninfected control, reached a peak at 100 d p.i., and decreased quickly after 140 d. The level of IFN-γ reached a peak after 80 d p.i., and decreased slowly after 140 d p.i., The levels of IL-4, IL-5 and IL-10 remained lower before 80 d, and increased sharply after 100 days. The levels of IL-4 and IL-10 reached peaks at 100 d p.i., and that of IL-5 at 140 d p.i. Conclusion The data suggest that the induction of Th2 antibody-mediated immunity (AMI) with a parallel expansion of Th1 cell-mediated inflammatory (CMI) responses are important mechanism of the host in defending against the metacestodes. Th1 CMI plays an important role at the early stage of infection, and Th2 AMI is important in the later stage of infection.