Cloning, expression and characterisation of a cysteine protease from Trichinella spiralis.

Cysteine protease is a superfamily of widespread proteolytic enzymes and plays a major role in larval invasion, migration, exsheathing, survival and immune evasion in parasites. In the present study, the gene coding cysteine proteinase of the nematode Trichinella spiralis (Owen, 1835) was cloned into pQE-80L and subsequently expressed in E. coli JM109. The rTsCP was purified and its antigenicity was identified by Western blot and ELISA. Using anti-rTsCP serum the native TsCP was identified in muscle larval crude proteins. The results of quantitative real-time PCR and immunofluorescence test demonstrated that the TsCP was expressed in all stages of T. spiralis and located mainly in cuticle, stichosome and reproductive organs. The immunisation of mice with rTsCP elicited Th2-predominant immune responses. Anti-rTsCP antibodies could partially inhibit the in vitro larval invasion of intestinal epithelial cells and kill the newborn larvae by an antibody-dependent cell-mediated dose-dependent cytotoxicity. The vaccinated mice exhibited a 54% reduction of adults and a 33% reduction of muscle larvae following challenge infection. The results suggested that the TsCP might be an indispensable protein in Trichinella invasion, development and survival of T. spiralis in hosts, and could be a potential vaccine target against infection.

[Observation of the Feline Intestinal Epithelial Cell Infected with Toxoplasma gondii].

Small intestine samples of neonatal cat were aseptically collected from the jejunum-ileum region and digested with collagenase XI/dispase I. Immunohistochemistry results showed that feline intestinal epithelial cells were successfully isolated and could be cultured. Cytokeratin was positive in the cytoplasm of feline intestinal epithelial cells. The cells were infected with the bradyzoites of Toxoplasma gondii Prugniaud strain, and the rupture of the cells was observed on the 72nd day post-infection. The sexual stage of T. gondii did not occur, however.

[Evaluation of high-resolution images application for wild medicinal plants macro monitoring: a case of Apocynum].

To investigate the resources of medicinal plant, such as wild Apocynum, supervised classification based on Principal Component Analysis (PCA) and texture feature were used to monitor wild medicinal plants from image captured by ZY-3 and World-view-2 and compare which satellite Image are more appropriate to monitor the wild medicinal plants. The research results shows that: for more complex growth conditions wild medicinal plants Apocynum, high-resolution images Worldview-2 is more suitable for its remote identification, the low-resolution satellite ZY-3 can only recognizes the wild medicinal plants which distributed intensively. If the study target distribution is more intensive and larger scale, and cultivated type medicinal plants, the use of satellite ZY-3 in low resolution remote sensing data to identify the target can be a good choice, it is not necessary to buy high-resolution data, in order to avoid waste of expenditure, for the scattered distribution, the high-resolution satellite imagery data may be indispensable to identify targets.

Enzymatically active Rho and Rac small-GTPases are involved in the establishment of the vacuolar membrane after Toxoplasma gondii invasion of host cells.

BACKGROUND: GTPases are the family of hydrolases that bind and hydrolyze guanosine triphosphate. The large Immunity-related GTPases and the small GTPase ADP-ribosylation factor-6 in host cells are known to accumulate on the parasitophorous vacuole membrane (PVM) of Toxoplasma gondii and play critical roles in this parasite infection, but these GTPases cannot explain the full extent of infection. RESULTS: In this research, RhoA and Rac1 GTPases from the host cell were found to accumulate on the PVM regardless of the virulence of the T. gondii strains after T. gondii invasion, and this accumulation was dependent on their GTPase activity. The real-time micrography of T. gondii tachyzoites invading COS-7 cells overexpressing CFP-RhoA showed that this GTPase was recruited to the PVM at the very beginning of the invasion through the host cell membrane or from the cytosol. Host cell RhoA and Rac1 were also activated after T. gondii tachyzoites invasion, which was needed for host cell cytoskeleton reorganization to facilitate intracellular pathogens invasion. The decisive domains for the RhoA accumulation on the PVM included the GTP/Mg2+ binding site, the mDia effector interaction site, the G1 box, the G2 box and the G5 box, respectively, which were related to the binding of GTP for enzymatic activity and mDia for the regulation of microtubules. The recruited CFP-RhoA on the PVM could not be activated by epithelial growth factor (EGF) and no translocation was observed, unlike the unassociated RhoA in the host cell cytosol that migrated to the cell membrane towards the EGF activation spot. This result supported the hypothesis that the recruited RhoA or Rac1 on the PVM were in the GTP-bound active form. Wild-type RhoA or Rac1 overexpressed cells had almost the same infection rates by T. gondii as the mock-treated cells, while RhoA-N19 or Rac1-N17 transfected cells and RhoA, Rac1 or RhoA + Rac1 siRNA-treated cells showed significantly diminished infection rates compared to mock cells. CONCLUSIONS: The accumulation of the RhoA and Rac1 on the PVM and the requisite of their normal GTPase activity for efficient invasion implied their involvement and function in T. gondii invasion.

Distribution of tick-borne diseases in China.

As an important contributor to vector-borne diseases in China, in recent years, tick-borne diseases have attracted much attention because of their increasing incidence and consequent significant harm to livestock and human health. The most commonly observed human tick-borne diseases in China include Lyme borreliosis (known as Lyme disease in China), tick-borne encephalitis (known as Forest encephalitis in China), Crimean-Congo hemorrhagic fever (known as Xinjiang hemorrhagic fever in China), Q-fever, tularemia and North-Asia tick-borne spotted fever. In recent years, some emerging tick-borne diseases, such as human monocytic ehrlichiosis, human granulocytic anaplasmosis, and a novel bunyavirus infection, have been reported frequently in China. Other tick-borne diseases that are not as frequently reported in China include Colorado fever, oriental spotted fever and piroplasmosis. Detailed information regarding the history, characteristics, and current epidemic status of these human tick-borne diseases in China will be reviewed in this paper. It is clear that greater efforts in government management and research are required for the prevention, control, diagnosis, and treatment of tick-borne diseases, as well as for the control of ticks, in order to decrease the tick-borne disease burden in China.

[Measurement of sown area of safflower based on PCA and texture features classification and remote sensing imagery].

To improve accuracy of estimation in planted safflower acreage,we selected agricultural area in Yumin County, Xinjiang as the study area. There safflower was concentrated planted. Supervised classification based on Principal Component Analysis (PCA) and texture feature were used to obtain the safflower acreage from image captured by ZY-3. The classification result was compared with only spectral feature and spectral feature with texture feature. The research result shows that this method can effectively solve the problem of low accuracy and fracture classification result in single data source classification. The overall accuracy is 87.519 1%, which increases by 7.117 2% compared with single data source classification. Therefore, the classification method based on PCA and texture features can be adapted to RS image classification and estimate the acreage of safflower. This study provides a feasible solution for estimation of planted safflower acreage by image captured by ZY-3 satellite.

[Cloning and structure analysis of sheep fertilin beta coding region].

Fertilin beta may play an important role in sperm-egg plasma membrane adhesion and fusion. To explore the effects of fertilin beta, the sperm membrane protein subunit, in the sheep fertilization process, we used RACE technique for cloning the full length cDNA of the coding region (CDS) of fertilin beta. The coding region was 2, 217 bp, which consists of 738 amino acids. The fertilin beta in the sperm membrane of sheep shares 79.4%, 66.7%, and 58.1% sequence identity with that in bovine, pig and human, respectively. The phylogenetic analysis of the fertilin beta gene family indicated the fertilin beta was clustered with bovine, and is closest to the one of bovine. This result is consistent with the result of the traditional classification. The protein structure analysis showed the disintegrin domain of sheep fertilin beta contains a TDE. Besides the above tripeptide sequence, the family member of ADAM (A Disintegrin and A Metalloprotease) follow the conserved sequence of ECD of X-D/E-E, and formed the conserved sequence of X-D/E-ECD. The pentapeptide sequence of the sheep fertilin beta is TDECE.