Table of Content

30 October 2006, Volume 24 Issue 5

Previous Issue    Next Issue

论著

Ultrastructural Alterations of Adult Schistosoma haematobium Harbored in Mice Following Artemether Administration

XIAOShu-hua;JürgUTZINGER;SHENBing-gui;MarcelTANNER;JacquesCHOLLET

2006, 24(5):  1-328. 

Asbtract ( )   PDF (404KB) ( )  

Related Articles | Metrics

Objective To perform a temporal examination of ultrastructural alterations in adult Schistosoma haematobium due to artemether Methods Eight mice infected with 100-120 S. haematobium cercariae for 81 days were treated intragastrically with 400 mg/kg artemether. At 24 hours, 3, 7 and 14 days post-treatment, groups of 2 mice were sacrificed and schistosomes collected by the perfusion technique. Worm samples were fixed and examined by transmission electron microscopy. Schistosomes were also obtained from 2 untreated mice that served as control. Results Typical ultrastructural alterations included swelling, lysis and vacuolization of the tegumental matrix, and disappearance of basal membrane. In sensory organelles and tubercles, there was extensive or local lysis of internal structure. In the musculature, parenchymal tissues, syncytium and gut epithelial cells, focal or extensive lysis, decrease in granular endoplasmic reticulum, vacuolization and degeneration of mitochondria were observed. These alterations became apparent both in male and female worms 24 hours post-treatment. In female worms, severe damage to the vitelline cells was also observed, resulting in the emergence of vacuoles, a decrease in granular endoplasmic reticulum, fusion of vitelline balls or even collapse of damaged vitelline cells. The most extensive tegumental alterations were observed 3-7 days post-treatment. Whilst 14 days post-treatment ultrastructural damage was still apparent, the tegument of some worms showed similar features to those recovered from untreated control mice. Conclusion Administration of artemether to mice infected with adult S. haematobium results in extensive damage to the ultrastructure in the tegument and subtegument tissues of the worms, confirming previous results with other schistosome species.

Preparation of Specific Antibodies Against Recombinant Em18Antigen and Detection of the Circulating Antigen

JIANGLi;LIXiong;LIHao;NIUXin-ling;FENGZheng

2006, 24(5):  2-332. 

Asbtract ( )   PDF (244KB) ( )  

Related Articles | Metrics

Objective To prepare specific antibodies against the recombinant Em18 antigen （ReEm18）， estab-lish a sandwich ELISA and detect the Em18 circulating antigen in patients^, sera. Methods Rabbits and BALB/c mice were immunized with the ReEm18 antigen， which was purified by affinity method for preparation of the specific poly-clonal and monoclonal antibodies. A sandwich ELISA was established by the specific antibodies. Results By immu-nizing with the ReEm18 antigen， high antibody level was reached with a serum dilution of 1 ∶ 204 800 and above in the immunized rabbits. After double selection by ELISA using the ReEm18 antigen and block ELISA using both AE-positive and negative control sera， 14 positive cell clones were obtained with an inhibition rate of more than 50%. Those mono- and poly-clonal antibodies were matched freely in sandwich ELISA tests for detecting the ReEm18 antigen. A combina-tion of monoclonal antibody No.9 and polyclonal antibody showed the best result. The sensitivity to detect ReEm18 anti-gen was at 3 ng/ml. Six of 11 AE sera were positive when tested with the sandwich ELISA system. Conclusion Highly specific polyclonal and monoclonal antibodies have been prepared， and a sensitive sandwich ELISA established. Preliminary result is suggested that a detectable level of Em18 circulating antigen is present in AE patients^, sera.

Effect of Combined Pentoxifylline and Albendazole againstEchinococcus multilocularis Infection in Mice

ZHOUHai-xia;MOJian-jie;CHENGen;BAOGen-shu;SHIDa-zhong

2006, 24(5):  3-332. 

Asbtract ( )   PDF (262KB) ( )  

Related Articles | Metrics

Objective To observe the effect of pentoxifylline （PTX）， albendazole （ABZ）， and a combination of PTX and ABZ in mice infected with Echinococcus multilocularis （E.M）. Methods The first part of the experiment was to observe the in vitro effect of PTX on the cultured E.M protoscolex. In the second part， mice were infected by abdominal inoculation of E.M and divided into groups given by ABZ 50 mg/kg·d， PTX 360 mg/kg·d， PTX 180mg/kg·d， and a combined regimen ABZ 50 mg/（kg·d）+PTX 180 mg/（kg·d）. Another infected group and a uninfected group served as controls which received normal saline only. 100 days post-treatment， the mice were sacrificed for further observation. Indicators included wet weight of the cyst， cyst inhibition rate， level of serum cytokines TGF-β determined by ELISA， IL-2 and IL-10 determined by radio-immunoassay （RIA）. Results The inhibition rate on cysts of the combined ABZ and PTX was 88%， considerably higher than 58 % of the group ABZ. The serum TGF-β and IL-10 decreased and IL-2 increased after treatment in comparison to the controls. Conclusion The PTX and ABZ combination shows better effect on E.multilocularis infection than that of single ABZ. PTX might help increase immunity of the mice.

Studies on the Immuno-Protection of ROP2 Nuclei AcidVaccine in Toxoplasma gondii Infection

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

2006, 24(5):  4-341. 

Asbtract ( )   PDF (325KB) ( )  

Related Articles | Metrics

Objective To study the protective effect of ROP2 nuclei acid vaccine in mice. Methods Forty-two BALB/c mice were divided into three groups. Each mouse in experiment group was injected with 50 μg recombinant plasmid pc-DNA3-ROP2 through musculus quadriceps fexoris. In control groups, each mouse was injected with 50 μg blank plasmid pc-DNA3 and with 50 μl PBS respectively. All mice were immunized for three times with an interval of three weeks. The volume was doubled for the final injection in the two plasmid groups. Blood, spleens and lymph nodes of 4 mice in each group were taken for the detection of CD4⁺, CD8⁺ T cells and cytokines 2 weeks after the final immunization. The rest mice in 3 groups were challenged with 500 tachyzoites of Toxoplasm gondii RH strain for further observation. Results The vaccine induced strong cellular and humoral immune response. The titer of antibody in serum was high after inoculation and recognized ROP2 protein antigen expressed in vitro. The lymphocyte phenotype was analyzed. CD4⁺ T cells proliferated sharply(69.5±3.4)%, and the ratio of CD4⁺/CD8⁺ increased considerably by （4.69±1.32）%（P<0.01）. The level of IL-2, IL4, IL-6, IL-12, IFN-γ and TNF in serum and cultured supernatant of spleen cells and lymph cells was higher in the experiment group than that in control groups, especially in serum. 88.9% mice in the experiment group were protected 180 hours after the challenge of T.gondii. The death time of mice in experiment group was delayed and the survival time was prolonged in comparison to that in control groups with a significant difference（P<0.01）. Conclusion The recombinant ROP2 nuclei acid vaccine shows fair immunogeni-city and obviously produces immuno-protection.

Investigation of Chigger Mites on the Rat Eothenomys miletus in Yunnan

HOUShu-xin;GUOXian-guo;MENXing-yuan;NIUAi-qin;DONGWen-ge;SHIWu-xiang

2006, 24(5):  5-344. 

Asbtract ( )   PDF (234KB) ( )  

Related Articles | Metrics

Objective To understand the species, species distribution, the dominant species and their interspecies interaction of chigger mites on Eothenomys miletus（a dominant species of rats） in Yunnan.　 Method 　 The rats were captured with mouse traps in 16 counties （or cities） during 2000-2004. All mites on the surface of two auricles of the hosts were collected and identified. The patch index （m*/m） and the coefficient of association （V） were adopted to judge the spatial distribution patterns and interspecies interaction of the dominant chigger mite species among different individuals of the rats （E. miletus）. Results 1157 individuals of E. miletus were captured from 16 counties （citys）. 37613 chigger mites （belonging to 3 subfamily, 9 genus and 80 species） were collected from the auricles （body surface） of 1157 rat hosts with a high “overall mite infestation rate” （68.2%） and “overall mite index” （32.5）. Six species of mites were found dominant on E. miletus： Leptotrombidium scutellare, Leptotrombidium sinicum, Helenicula simena, Leptotrombidium eothenomydis, Herpetacarus hastoclavus and Leptotrombidium hiemalis. The distribution of the chigger mites among different individuals of E.miletus showed an aggregation pattern. Both positive and negative association existed between each two dominant species of chigger mites. Conclusion The species composition of chigger mites on Eothenomys miletus is complex with abundant individuals, which reflects a high species diversity of the mites. The main species of chigger mites tend to an aggregation on the body surface of E. miletus.

Molecular Relationship of Eurytrema coelmaticum Inferredfrom 18S rRNA Sequence

ZHENGYa-dong;LUOXue-nong;SHICheng-hong;ZONGRui-qian;JINGZhi-zhong;CAIXue-peng

2006, 24(5):  6-248. 

Asbtract ( )   PDF (266KB) ( )  

Related Articles | Metrics

Objective To elucidate the taxonomic position of Eurytrema coelmaticum by using molecular technology. Methods 18S rRNA fragment was amplified from E. coelmaticum genomic DNA by specific conservative primers and sequenced. Homology and phylogenic tree of 18S rRNA sequences between E. coelmaticum and other Dicr-ocoeliidae trematodes were analyzed and constructed by DNAStar and MEGA3 respectively， and their evolutionary relationship was determined. Results E. coelmaticum 18S rRNA sequence was with high homology to those from Dicrocoelium dendriticum， Lyperosomum collurionis and Brachylecithum lobatum. Among them， the diversity of E. coelmaticum from D. dendriticum was 2.42%， and that from L. collurionis was 1.75%; D. dendriticum and B. lobatum were closer in evolution only with 1.09% diversity. Conclusion For Dicrocoeliidae trematodes， classification based on 18S rRNA target is valid and the sequences are highly conservative. E. coelmaticum is evolutionarily closer to L. collurionis than to D. dendriticum and B. lobatum.

Immune Response and Immunopathology in Inducible Costimulatory Molecule （ICOS） Transgenic Mice Infected with Schistosoma japonicum

XIAChao-ming;PUXiang-ke;GONGwei;LUOwei;ZHANGHui-qin;DENGZhong-bin;XUEZhi-mou

2006, 24(5):  7-352. 

Asbtract ( )   PDF (248KB) ( )  

Related Articles | Metrics

Objective To establish the ICOS transgenic mice schistosomiasis japonica model and to observe the immune response and immunopathology of the model. Methods The transgenic mice were infected with Schistosoma japonicum. Spleen cells and sera of mice were harvested at week 4， 6， and 8 after infection. The cytokines IFN-γ and IL-4 were measured in culture supernatans by ELISA. The serum IgG， IgG1 and IgG2a were measured by ELISA at different period of infection. Liver tissue sections were prepared with HE staining. Liver granuloma formation was observed under microscope. Results The expression level of IFN-γ showed no significant difference between ICOS transgenic mice and control， while that of IL-4 in ICOS transgenic mice was significantly up-regulated to 20.81±1.95 and 25.31±3.37 pg/ml at week 6 and 8 respectively （P<0.01）. The serum IgG and IgG1 in ICOS transgenic mice were also significantly higher than those in control. Th2 differentiation index and IgG1/IgG2a were used to evaluate the immune regulation balance of Th1/Th2， and results showed that Th2 response in ICOS transgenic mice was significantly stronger than that of the control. The egg granuloma response in ICOS transgenic mice was also significantly stronger than that in control（P<0.01）. The rate of egg granuloma enlargement was 24.48% and 26.37% at week 6 and 8 respectively. Conclusion The findings suggest that there is stronger Th2 type response in ICOS transgenic mice infected with Schistosoma japonicum and ICOS may play an important role in the egg granuloma formation of Schistosoma japonicum.

实验研究

Development of PCR Assay for Detection of Angiostrongyluscantonensis in Pomacea canaliculata

ZHANGYi;ZHOUXiao-nong;LIUHe-xiang;LvShan;LILi-sha;LINJin-xiang;LIYou-song

2006, 24(5):  8-355. 

Asbtract ( )   PDF (221KB) ( )  

Related Articles | Metrics

Objective To establish a PCR assay for detecting the third-stage larvae of Angiostrongylus cantonensis in Pomacea canaliculata. Methods Polymerase chain reaction primers were designed by the software Lasergene， based on the specific cDNA of the third-stage larvae of A.cantonensis in Genbank. The total RNA was prepared from the third-stage larvae of A.cantonensis and of the snails by TRIzol one-step protocol. Amplification by RT-PCR was carried out following the kit protocol. Results RT-PCR assay revealed a clear differentiation between infected and negative snails. When a mixture of the total RNA from the negative snails and the third-stage larvae of A.cantonensis was tested by the PCR assay， the detectable level was 128 pg RNA， a concentration close to one third-stage larva of A.cantonensis， mini-mum concentration that could be found by naked eyes. The minimum detected total RNA concentration of the third-stage larvae of A.cantonensis was 105 pg by PCR assay. Conclusion A PCR assay has been developed for detecting A.cantonensis larva in Pomacea canaliculata.

Construction and Screening of Recombinant Fowlpox Virus ExpressingEimeria tenella F2 Hybrid Strain SO₇ Gene

YANGGui-lian;ZHANGXi-chen;ZHAOQuan;LIJian-hua;YINJi-gang

2006, 24(5):  9-359. 

Asbtract ( )   PDF (279KB) ( )  

Related Articles | Metrics

Objective To Construct the recombinant fowlpox virus expressing Eimeria tenella F2 hybrid strain SO₇ gene. Methods A recombinant expression plasmid pUTA-SO₇ was constructed by inserting the SO₇ gene of Eimeria tenella F2 hybrid strain into downstream of a hybrid poxvirus promoter which was flanked by the TK gene of fowlpox virus（FPV）. The constructed pUTA-SO₇ was firstly transfected into chicken embryo fibroblast cells（CEF） pre-infected with FPV strain 282E4 by using liposome， then the viruses resulted from the transfection were selected for 2 passages by culturing in CEF cells with MEM medium containing 40 mg/L 5-bromo-2-deoxy-uridine（BrdU）. The selected viruses were plaque-purified in CEF cultured with MEM medium without BrdU. Results Polymerase chain reaction （PCR）， indirect immunofluorescence assay and Western blotting showed that SO7 gene was expressed in recombinant fowlpox virus. Conclusion The recom-binant FPV （rFPV） expressing the SO₇ gene has been obtained.

Cloning， Expression and Phylogenetic analysis of Schistosoma japonicum Calcyphosine Gene

JUChuan;PENGJian-xin;XUBin;WANGWei;FENGZheng;HUWei

2006, 24(5):  10-365. 

Asbtract ( )   PDF (447KB) ( )  

Related Articles | Metrics

Objective To clone and express Schistosoma japonicum （Sj） calcyphosine gene， and purify the exp-ressed protein. Method The encoding sequence selected from Sj cDNA library was amplified by PCR. After subcloned into prokaryotic expression vector pET-28a， the expressed protein was purified with His·Tag affinity chromatography. Western blotting was used to detect the immunogenicity. The structure and functions of the protein were analyzed by bioinformatics method， and the phylogenetic tree of the protein was drawn. Result The recombinant protein was specifically recognized by the Sj infected rabbit serum. The bioinformatics analysis showed 4 EF-hand domains. Besides， it was predicted that Sj calcyphosine contains two phosphorylation sites for protein kinase C， eight phosphorylation sites for casein kinase II and one N-myristoylation site. The Sj calcyphosine belonged to type-II calcyphosine. Conclusion The calcyphosine gene is a calsium-binding protein and might be a potential candidate for diagnosis， vaccine or drug target.

An Approach to the Mechanism of Matrine and Albendazole Against Echinococcus multilocularis Infection in Mice

ZHANGRui;JINGTao

2006, 24(5):  11-369. 

Asbtract ( )   PDF (231KB) ( )  

Related Articles | Metrics

Objective To assess the immune status and metabolic reaction of hepatic enzymes on mice with alveolar echinococcosis （AE） after treatment with matrine （Mat） and albendazole （ABZ）. Methods Mice with AE were treated with single dose Mat, ABZ and combined Mat and ABZ respectively for 60 days. The serum level of IL-2, IL-4, IL-6 and TNF-α was detected before and after treatment. NO, LD content and LDH, NOS, iNOS, Na⁺-K+ ATPase, Ca²⁺-Mg²⁺ ATPase activities in hepatic tissue homogenate from the mice were measured by chromatometry. Results The level of IL-4, IL-6 and TNF-α decreased in the treated groups than infected control （P<0.05）, and especially that of IL-4 and TNF-α in the drug-combination group. While the level of IL-2 increased in the combination group than the infected control （P<0.05）. The content of NO and the activity of NOS and iNOS in hepatic tissue decreased after treatment than control （P<0.05）. iNOS in Mat and combination groups decreased more significantly than that of ABZ group （P<0.05）. The LDH activity also decreased after treatment （P<0.05）, however, the decrease of LD occurred only in the combination group （P<0.05）. The activity of Na+-K+ ATPase and Ca²⁺-Mg²⁺ ATPase increased in the treated groups （P<0.05） with more considerable increase of Ca²⁺-Mg²⁺ ATPase in Mat and combination groups than the ABZ group（P<0.05）. Conclusion Matrine may strengthen the immunity of the mice and shows an inhibitory effect on the growth of Echinococcus multilocularis in vitro and in vivo， which is posssibly related to the intervention of calcium ion passages and reversion of the multi-drug resistance.

综述

Innate Immune Defense in Anopheline Mosquitoesagainst Plasmodium Infection

QIUZong-wen;ZHANGXi-lin

2006, 24(5):  12-374. 

Asbtract ( )   PDF (246KB) ( )  

Related Articles | Metrics

On the basis of the research on interaction between plasmodium and mosquito vector， the mechanism of innate immune defense responses in anopheline mosquitoes against plasmodium infection has been studied. The innate immune defense may be applied to confine and kill malaria parasites under migration and development， and contribute to an effective control strategy on malaria vectors.

Molecular and Chemical Mechanism of Trichomonas vaginalis-inducedContact-dependent Cytotoxicity

YANGShu-guo;TIEChao-nan;WANGYa-jing

2006, 24(5):  13-378. 

Asbtract ( )   PDF (238KB) ( )  

Related Articles | Metrics

Trichomonas vaginalis parasitizes in human genitourinary tract. The protozoon adhering to target cell plays a critical role in its contact-dependent cytotoxicity. The enzymes synthesized by T.vaginalis can hurt vaginalis epithelial cells（VECs） directly. The focal immune reaction in the location parasitized by the parasite may provide an immunologic protection. Meanwhile， inflammatory factors and immune cells may aggravate the situation. In general， the T. vaginalis-induced contact-dependent cytotoxicity is a result of the involvement of some molecular and chemical factors.

Review on the Biological Research of Human Demodex

ZHOUShu-heng;WANGLin-lan

2006, 24(5):  14-381. 

Asbtract ( )   PDF (248KB) ( )  

Related Articles | Metrics

This article summarizes the present researches on biology of human Demodex about the methods of examination, morphology of adult parasite, biological habits and characteristics, and in vitro survival.

学术争鸣

Re-understanding of Liver Cirrhosis Induced by Schistosomiasis Japonica

ZHANGWu-cheng;MAOYa-fei

2006, 24(5):  15-384. 

Asbtract ( )   PDF (208KB) ( )  

Related Articles | Metrics

Whether the hepatic pipestem fibrosis induced by schistosomiasis japonica can result in cirrhosis，confu-sion exists among parasitologists in China. Evidence from national and international pathologists and clinicians confirmed that the pipestem fibrosis could develop into cirrhosis undoubtedly. Owing to different pathogenic causes， the characters of cirrhosis are different. To re-understand cirrhosis induced by schistosomiasis japonica is of significance for the diagno-sis and treatment of the advanced patient.

研究简报

Construction of Sjcb2 DNA Vaccine and its Expression in HeLa Cells

HUYong-xuan;XIAOJian-hua;HUANGJia-fang;YANGQiu-lin

2006, 24(5):  16-386. 

Asbtract ( )   PDF (214KB) ( )  

Related Articles | Metrics

A recombinant plasmid containing cathepsin B endopeptidase of Schistosoma japonicum （Sjcb2） was constructed, indentified by PCR, restrictive enzyme, digestion and DNA sequencing, and expressed into mammalian cells. Immunochemistry examination showed that the Sjcb2 gene can be expressed in the eukaryotic system, providing a basis for the development of schistosome DNA vaccine.

The Injury of Metronidazole on Morphology of Giardia lamblia in Vitro

TIANXi-feng;WEIRu;YANGZhi-hong;LUSi-qi

2006, 24(5):  17-388. 

Asbtract ( )   PDF (212KB) ( )  

Related Articles | Metrics

Trophozoites of Giardia lamblia were axenically cultivated with modified TYI-S-33 medium contained 500 μg/ml metronidazole（12h LC₅₀）. The morphology of drug-treated trophozoites was observed with light and electron micro-scopes at 2, 4, 8, 12 h respectively. The light microscopy revealed that the trophozoites treated with MTZ showed swollen, detached from the wall of the culture tube, and were with vacuoles in the cytoplasm. Movement of the flagella become slowly or stopped. Electronic microscopy showed that the trophozoites were swollen and deformed; lots of vacuoles were seen in the cytoplasm; the contents of cytoplasm were depleted and the nuclei deformed. This study indicated that MTZ has injured the morphology of G.lamblia.

Cloning and Sequence Analysis of a Partial Gene ofTrichomonas vaginalis dsRNA Virus

ZHAOYue-ping;ZHANGXi-chen;CHENLi-feng;LIJian-hua;YINJi-gang;LIUQuan;GONGPeng-tao

2006, 24(5):  18-390. 

Asbtract ( )   PDF (208KB) ( )  

Related Articles | Metrics

A pair of degenerate primers were designed following the published nucleotide sequence of Trichomonas vaginalis virus（U08999， NC003873， NC003824， NC003834）. Using the total nucleic acids extracted from the Trichomonas vaginalis as template， RT-PCR was performed with the primers to obtain a fragment of the TVV. The product was cloned， sequenced and compared with the sequences available in the GenBank. The size of the amplified gene was 1 454bp， which shares 82.9% sequence identity with the Trichomonas vaginalis virus T1.

Genetic Identification of Acanthamoeba sp. CJY/S1 andCJY/S2 Isolated from Soil

ZHENGShan-zi;XUANYing-hua;WANGYue-hua;SHENCheng-hua;CUIChun-quan

2006, 24(5):  19-392. 

Asbtract ( )   PDF (177KB) ( )  

Related Articles | Metrics

Two isolates of Acanthamoeba sp. CJY/S1 and CJY/S2 were received from soil in Yanji of Jilin Province. Full 18S rDNA gene was amplified using PCR, cloned and sequenced. The results were analyzed by software Clustal X. The full length of CJY/S1 and CJY/S2 is 2255 bp and 2252 bp respectively, both belong to T4 genotype.

Effect of γ-interferon on Hepatic Granuloma Formation in MiceInfected by Cysticerci of Taenia saginata asiatica

LIPu;BAOHuai-en;RONGJU-quan;SHENZhen-hua;DANGRong-min;HEXiao-fei;WURong;JIANGShui

2006, 24(5):  20-394. 

Asbtract ( )   PDF (219KB) ( )  

Related Articles | Metrics

Immunohistochemical streptavidin biotin-peroxidase complex method was used to investigate the effect of γ-interferon （IFN-γ） on the hepatic granuloma formation and liver fibrosis in mice infected with Taenia saginata in Duyun area of Guizhou Province. The results reveal contrary relation between the level of IFN-γ in the liver and the degree of liver fibrosis （p<0.01）. The injection of IFN-γ considerably decreased （p<0.01） the area and size of granuloma （p<0.01）.

Biological Identification on Sub-cultivation Cells ofSchistosoma japonicum Adult Worms in Vitro

LIUWei;ZENGTie-bing;ZENGQing-ren;CAIChun;ZHANGZu-ping;GONGYan-fei;CAILi-ting;ZHANGShun-ke;XUXi-ping

2006, 24(5):  21-397. 

Asbtract ( )   PDF (306KB) ( )  

Related Articles | Metrics

Cultivation of cells from 30-day old Schistosoma japonicum （S.j） adult worms showed that the growth features of the cells were semi-floating and accumulative. The survival rate of the primary cells, passage cells prior to the 5th generation and recovered cells was all up to 90%. Phases of cell division were observed during cultivation. Chromosome karyotype of the 5th generation cells possessed diploid feature of the blood-flukes（2n=8 in number）. Ultrastructure of the 5th generation cells showed that four types of cells in normal morphology and three types of cells in abnormal morphology were both viewed. It is suggested that some of the cells from S.j adult worms were subcultured successfully in the 1640-40 defined medium.