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Objective: To realize the rapid on-line detection of defective rice flour. Methods: Non-contact data acquisition of rice flour blocks through cameras, image upload and processing, obtained the contour perimeter and area, approximate contour perimeter and area, approximate contour points and radius of the contour circle. According to the characteristics of rice flour block sample data, the SVM classification algorithm was used to analyze the sample set composed of multi feature data of rice flour block. Results: Compared with five algorithms, the average accuracy of GBDT classification algorithm was 89% with elapsed time of 1.10 s. The average accuracy of KNN classification algorithm was 88% with elapsed time of 0.23 s. The average accuracy of logistic regression classification algorithm was 88% with elapsed time of 0.68 s. The average accuracy of random forest classifica-tion algorithm was 87% with elapsed time of 0.47 s. The average accuracy of tree classification algorithm was 87% with elapsed time of 0.084 s. SVM classification algorithm had the highest average detection accuracy, up to 95%, and the shortest average elapsed time of 0.000 97 s. Conclusion: SVM classification algorithm has the characteristics of high accuracy and low elapsed time, which adapt the on-line detection of defective rice flour.

Objective: To understand the endemic situation dynamics of schistosomiasis in domestic animals (mainly bovine) in mountainous endemic regions, so as to provide the reference for evaluating the control effect and improving control strategy., Methods: Two representative pilots (Renmei and Dacang) in mountainous schistosomiasis endemic regions were selected for survey. The schistosome infection status of bovine was investigated by the miracidium hatching method, the pasture of bovine were investigated by home visiting, and the distributions of wild feces and Oncomelania snails, and the snail schistosome infection status were also investigated in April and September every year., Results: The schistosome infection rates of bovine reduced by 98.4% and 93.8% in two pilots in 2007 compared with those in 1993, and the infection intensities also showed a decline trend. The infection rate of wild faces was 0 in Renmei pilot since 1995, while in Dacang pilot, the infection rate of wild feces fluctuated in 2007, and the intensities of living snails and infected snails showed a declined trend., Conclusions: Due to the special natural environment of mountainous endemic regions, there is a dot-like or band-like distribution of endemic areas. The strengthening of schistosomiasis examination and chemotherapy will rapidly reduce endemic situation. However, to completely interrupt the transmission of schistosomiasis, we should emphasize environmental modification and domestic animal management.

Objective: To get the characteristic differentially expressed genes of Schistosoma japonicum from three important reservoir hosts: yellow cattle, water buffalo and goat, so as to find the genetic markers to identify the various sources of the parasite reservoir hosts., Methods: The 49 d worms were collected from artificially infected animals, and the total RNA(s) of worms were extracted and reverse-transcripted to cDNA, and then hybridized with custom-built microarray to screen characteristic differentially expressed genes of every host, and the microarray results were validated by the real-time PCR method., Results: From results of microarray, we got 3 characteristic differentially expressed genes of S. japonicum from yellow cattle, 4 from water buffalo and 7 from goat. We verified schistosome samples from three reservoir hosts in another experiment, the results showed that 2 in yellow cattle, 3 in water buffalo, and 5 in goat were verified to be consistent with microarray results., Conclusions: The ten characteristic differentially expressed genes of S. japonicum from three reservoir hosts screened by microarray might be used as genetic markers to identify the various sources of reservoir hosts for S. japonicum.

Objective: To clone, express and characterize a tegument protein gene of Schistosoma japonicum (Sj29) , and investigate the immune protection of the recombinant protein against S. japonicum in mice., Methods: The gene coding for Sj29 protein was amplified by PCR, and the sequence was analyzed by bioinformatics tools. Partial fragment of Sj29 gene was subcloned into the prokaryotic expression vector pET28c(+). The recombinant plasmid was transformed into E. coli BL21 (DE3) and induced the recombinant with IPTG. The recombinant protein (rSj29) was purified by His-binding-resin affinity chromatography and characterized by Western blotting. Three groups each with 10 BALB/c mice were immunized subcutaneously three times (two weeks interval) respectively with 100 microl recombinant rSj29 (0.1 mg/ml) , adjuvant or PBS. At the 15th day after the final inoculation, each mouse was challenged by 40 +/- 2 cercariae of S. japonicum. At the 53rd day after infection, the mice were sacrificed to obtain the number of adult worms, number of eggs in liver and feces. Serum samples were collected at pre-immunization and certain time after immunization, and were analyzed for IgG by ELISA. The localization of rSj29 in worms of different developmental stages was demonstrated by immunofluorescent technique. mRNA expression level of Sj29 gene in worms of different developmental stages and three groups after infection was detected by quantitative real-time PCR., Results: A 576 bp Sj29 gene fragment was obtained. The recombinant protein rSj29 with Mr 22,900 was expressed in the form of inclusion body. The recombinant rSj29 can be recognized by sera of mice immunized with rSj29 and sera of infected mice. The number of adult worms (15.4 +/- 5.9), number of hepatic eggs (40,143.3 +/- 2,995.9) and number of fecal eggs (3,803.9 +/- 110.9) in recombinant protein group were significantly higher than those of PBS control group (20 +/- 3.4, 49,318.1 +/- 6,648.3, 5,238.1 +/- 303.5, respectively) (P < 0.05) . There was a high level of specific IgG against rSj29 (maximum dilution 1:32000) in recombinant protein group. Immunohistochemical analysis showed the Sj29 protein expressed on the surface of different stages of S. japonicum. mRNA level of Sj29 was the highest at the 32nd day post-infection., Conclusion: The recombinant protein rSj29 induces certain degree of protective immunity in mice.

Cellular immunity plays an important role in defense against diseases, such as pathogenic infection, autoimmunity and tumor. With the progress of molecular immunology, mechanisms of T cellular immunity, and the T cell epitopes and functional genomics, studies on the prediction based on data-derived for T cell epitopes has been highlighted, and could be one of the useful tools for application in vaccine development. This review summarizes theory and methodology of prediction for helper T cell epitopes, and their application in vaccine development against parasites, and new research directions are also discussed.

Objective: Current advances in reverse vaccinology based on the principle of "sequence-structure-function" and such integrated platform technologies as immunoinformatics, computer-aid design, and various high-throughput omics (including genomics, transcriptomics and proteomics) may pave a new way for the discovery of candidate vaccine molecules against schistosomiasis. Both theoretical prediction and experimental approaches conventionally used in the field of reverse vaccinology are briefly introduced in this review; and the applications of these approaches to screening and confirming candidate Schistosoma vaccine molecules are also summarized. Furthermore, potential research prospects of the application of reverse vaccinology to Schistosoma vaccine development are discussed by simulating immune effect mechanisms of immunization with radiation-attenuated cercaria vaccine in animal hosts and naturally acquired immunity in human population.

Wnt proteins together with their downstream effectors forms a set of important signal pathways. The Wnt signal pathway is important in a wide variety of development processes including cell growth, cell differentiation, cell polarity and apoptosis. Wnt4 is a key regulator of gonadal differentiation in humans and mice, playing a pivotal role in early embryogenesis. With RACE technique based on a EST identified in our lab, a novel gene including a complete open reading frame was cloned and named Sjwnt4 (GenBank accession No. DQ643829). Sequence analyses showed that SjWnt4 had a typical characteristics of Wnt family proteins, sharing 43% similarity to Dugesia japonica and 37% to human Wnt4. The ORF of Sjwnt4 contains 1311 nucleotides, encoding 436 amino acid with 49.6 kD molecular weight. Real-time PCR analysis from the worms of various stages of S. japonicum revealed that the mRNA level of Sjwnt4 is highest in the 19 days schistosomula, followed by 44 days female worms, 14 days schistosomula, 31 days adult worms and 44 days male worms, suggesting a stage-and-gender differential express. The Sjwnt4 cDNA fragment was subcloned into a modified expression vector pGEX-4T-2 and transformed into E. coli BL21 (DE3) cells, and the production of recombinant Sjwnt4 protein fused to a GST tag was analysed. In the presence of IPTG, the 76kD fusion protein was expressed in included bodies. Western-blotting revealed that the fusion protein could be recognized by the rabbit serum specific to Schistosoma japonicum adult worm antigen preparation. The study provides important basis for investigating the regulation mechanism of the Wnt signaling pathway during the development especially gonadal differentiation processes of Schistosoma japonicum.

Based on the phenomenon of the natural anti-schistosomiasis in Microtus fortis, the sera from normal Microtus fortis were employed to immunoscreen the cDNA library of adult Schistosoma japonicum (Chinese strain), two positive clones were obtained, RACE technique was further applied to amplify one of the clones, and a cDNA fragment with an ORF was identified. Sequencing revealed that it was a novel gene of Schistosoma japonicum, and it was named SjMF4 (Schistosoma japonicum Microtus fortis 4). Then the structure and functional motifs of SjMF4 were analysed. The gene was subcloned into pET-28a(+) vector; the recombinant protein showed good antigenicity in Western blotting. The gene was further subcloned into eukaryotic expression vector pcDNA3 to construct the DNA vaccine containing SjMF4. Immune experiments in mice showed significant protection that the recombinant plasmid did induce 28.64%+/-3.82% worm reduction and 21.73%+/-3.98% egg reduction than controls against the Schistosoma japonicum cercaria challenge.

The cDNA fragments of interest were amplified using Sj lambda ZipLox library as the templates by PCR and then cloned into a eukaryotic expression vector p-CMV-GH; A small number of DNA fragments inserted in the recombinants was identified by restriction cleavage, EST sequencing and bioinformatical analysis; mice were injected intramuscularly with the expression library (L-CMV-SjR) or sublibraries(L-CMV-SjR1, L-CMV-SjR2 and L-CMV-SjR3), immunized mice were challenged with Schistosoma japonicum cercariae on day 35, the levels of IgG antibodies in sera from the immunized mice were detected by ELISA. The results demonstrated that a partial cDNA expression library of S.j, with approximately 10(5) transformants, was constructed, most of the recombinants contained the insert DNA fragments of interest, and these fragments had the features of protein-coding sequences for Schistosome. There were no significant differences for the levels of IgG antibodies in sera from all of the immunized groups. Mice immunized with L-CMV-SjR, L-CMV-SjR1 and L-CMV-SjR2 developed significant protective effect against Sj infection compared to control mice injected with the empty plasmid, the rate of worm reduction was about 30%.