Objective] To investigate the possible mechanism underlying the killing of Culex quinquefasciatus larvae by Lagenidium giganteum from the biochemical point of view. [Methods] The activities of alkaline phosphatase(AKP), acid phosphatase(ACP) and esterase(EST) were observed by using calcium cobalt method, lead nitrate method and naphthol method. Results were photomicrographed and analysed quantitatively by image analysis using computer. [Results] The activities of AKP and ACP were decreased while the activities of EST were increased among the infected groups with different infection intensities. [Conclusions] The changes of these enzyme activities might be one of the important mechanisms of action of Lagenidium giganteum against Culex quinquefasciafus larvae.

This article reviews the epidemiological investigation of taeniasis saginata in 10 counties of 7 provinces/ autonomous regions in western China.The morphological observation of adult worms,molecular identification of 10 isolates of the worms,experimental infection on pigs and cattle with Taenia saginata and T.asiatica,observation on development and bio-logy behavior of cysticercus,and pathological changes in the intermediate host pig and cattle revealed that T.asiatica is a new species,instead of a subspecies of T.saginata.

Objective To analyze the quantitative change of 18 elements in Culex quinquefasciatus Larvae infected by Lagenidium giganteum (Oomycetes:lagenidiales), and to explore possible mechanism of mosquito-killing by the fungus. Methods. Elements in the mosquito larvae at different developmental stages from infected and non-infected (control) groups were detected with automatic bioassay machine. Results . At the early stage of infection, content of Ca and Cu in the infected group was markedly lower while the content of Co and Cd were higher than the control. In 24 hrs after infection, the content of Ca, Mg, Na, P, Fe, Zn, Cu, Mn and Cr was significantly lower while that of K, Mo, Co, Ni, Al, Cd and Pb were higher than those in non-infected larvae. No marked difference was found for the content of Sr and B between the two groups. In 48 hrs after infection, considerable difference was found in 17 elements between infected and non-infected larvae, with only one exception of Sr. Conclusion . Many elements which play an important role in maintaining the vitality of the mosquito larvae decreased and some of the heavy metal elements accumulated after the infection of Lagenidium giganteum. This might be a part of the killing mechanism to Culex quinquefasciatus larvae.

Objective To identify the types of Taenia saginata isolated from Dali of Yunnan Province, and from Duyun and Congjiang of Guizhou Province.\ Methods\ Genomic DNA was isolated, and the mitochondrial cytochrome C oxidase subunitⅠ(mtCOⅠ) genes were amplified by polymerase chain reaction(PCR) and analyzed by PHYLIP software package.\ Results \ The mtCOⅠgene sequences of Lanping sample were identical to that of T\^saginata asiatica known in Taiwan, and the samples obtained from Dali and Duyun showed the same mtCOⅠgene sequences, while the sample from Congjiang had the same mtCOⅠgene sequences as T\^saginata . The homology between these two groups of gene sequences was 97\^44%, while the homology of amino acid sequences reached to 99\^16%. The constructed phylogenetic tree revealed that the relationship between T\^saginata asiatica and T\^saginata is closer, both are distant relative to T\^solium and other species of cestodes.\ Conclusion \ The Taenia prevalent in Lanping, Dali and Duyun is identified as T\^saginata asiatica , while that isolated in Congjiang is the typical T\^saginata.

Using immunohistochemical method,the antigens were shown to be mainly located in the cecum,tegument,esophagus,pharynx,excretory bladder,uterus and oral sucker of Pagumogonimus skrjabini.Histochemical analyses showed that antigens contained enzymes such as acid phosphatase (ACP),alkaline phosphatase (AKP),and acetyleholinesterase (AChE).Other chemical substances,for example,alkaline protein,basic protein,glycogen and acid mucopolysaccharides were also detected in the antigens of P.skrjabini.

Objective:To study the gene expression spectrum of Th cell immune response in acute and chronic toxoplasma infection in BALB/c mice.Methods:BALB/c mice were infected with toxoplasma tachyzoite (1?104/m,0.5 ml) by intraperitoneal injection.Two mice were killed at 6th and 12th day postinjection.The immune response gene expressing levels in mice spleen cells were detected with 128 kind gene microarray chips.Partial of the results were determined with Real time-PCR.Results:There were 20 genes changed after toxoplasma infection.Eight of them (Gata-3,Ccr3,Ccr4,Bcl6,Nfatc1,CD80,Fos,CD69) were regulated upward and twelve genes (T-bet,CIITA,Irf1,Mapk9,Nfatc3,Fasl,Tyk2,Lat,Mapk10,Socs3,Socs6 and Yy1) were regulated downward.On the whole,expression of Th2 response genes presented a up trend,and Th1 response genes presented a down trend.The results of Real time-PCR were accordant with microarray in the expression of Gata-3 and T-bet gene.Conclusion:According to the Th cell immune response gene expression spectrum,Th1 immune response is dominant in the acute infention when mice are infected by toxoplasma.Then,it is biased toward Th2 immune response.

Objective:To explore the polarization of Th1 and Th2 immune response and the changes of transcription factor(T-bet and GATA-3) in BALB/c mice infected with toxoplasma gondii.Methods:Sixty BALB/c mice were infected with toxoplasma tachyzoite(1?104/m,0.5 ml) by intraperitoneal injection and thirty BALB/c mice only received an injection of same amount of normal saline as control.After injection,two mice of infection group and one mouse of control group were killed in odd number days.Then,the serum IFN-? and IL-4 were measured by ELISA,and the mRNA expression of T-bet and GATA-3 in mice spleens were detected by Real-Time RT-PCR.Results:In the infection group of mice,the IFN-? was remarkable increased at the fourth day and kept the peak from the 5th day to 7th day.Then,it decreased to normal level at 9th day postinjection;but IL-4 was remarkable increased at the 8th day and reached to the peak at 9th day.Then it decreased to normal level at 15th day postinjection.The mRNA of T-bet expression was increased at the third day and kept the peak from the 5th day to 7th day.Then,it decreased to normal level at 9th day postinjection.The mRNA of GATA-3 expression was increased at the 7th day and rised to the peak at 11th day.Then,it decreased to normal level at 13th day postinjection.There were not obvious changes of IFN-? and IL-4 or T-bet and GATA-3 in normal mice.Conclusion:The Th1 immune response is dominant in acute infection when mice are infected by toxoplasma.Then it biases toward Th2 response at 9th day to 13th day postinfection.The shift of Th1/Th2 polarization influences the finale of toxoplasma infection.

Objective To explore possible physiological and biochemical mechanisms of Lagenidium giganteum infection in killing mosquito larvae. Methods The content of lipid and the activities of esterase and lipase between the normal and infected mosquito larvae were observed with histochemical method. The results were photomicrographed and analysed by image analysis using computer. Results In 24 hrs after infection, the content of lipid in the infected Culex quinquefasciatus larvae was lower while the activities of esterase and lipase in the larvae were higher than the control. In 48 hrs and 78 hrs after infection, the content of lipid in the infected larvae of C. quinquefasciatus and Ae. albopictus were significantly lower while the activities of esterase and lipase were significantly higher than those of control. Conclusion The content of lipid in the mosquito larvae decreased while the activities of esterase and lipase increased after the infection of Lagenidium giganteum . The disorder of lipid metabolism might be part of the killing mechanisms to C. quinquefasciatus and Ae. albopictus larvae.

Objective To make molecular identification for 9 isolates of Taenia saginata from 4 provinces.Methods Genomic DNA was extracted from the segments of adult tapeworms collected from Taoyuan of Taiwan(TW1),Duyun of Guizhou(DY1,DY2),Congjiang of Guizhou(CJ1,CJ2,CJ3,CJ4),Dali of Yunnan(DL1) and Wushi of Xinjiang(XJ1) respectively.PCRs were carried out with 13 random primers.A phylogenetic tree of different geographical strains was constructed.Results 331 DNA fragments were amplified.The number of DNA fragments amplified by single primer was between 3 and 28.The average number of amplified DNA fragments by the 13 primers was 14.15.The average number of fragments from the 9 isolates of T.saginata was 14.08.Phylogenetic tree revealed that there were two branches in the tree,DY1,DY2,DL1 and TW1 occupied one branch,while CJ1,CJ2,CJ3,CJ4 and XJ1 occupied the other one.Conclusions By the RAPD analysis,the isolates DY1,DY2,DL1 and TW1 belong to Taenia saginata asiatica,and the isolates CJ1,CJ2,CJ3,CJ4 and XJ1 belong to T.saginata saginata.

The total protein of Toxoplasma gondii RH strain tachyzoites was separated by two-dimensional electrophoresis (2-DE), and Western blotting was performed to find out distinct antigens. 209 spots were detected through Coomassie brilliant blue-stained small gels (7?8 cm, pH 3-10). Western blotting showed 17 specific antigen spots with sera of the experimental group and two nonspecific spots with the control sera.