Objective To explore whether NO is able to induce apoptosis in Toxoplasma gondii tachyzoites.Methods Apoptosis induced by NO in T\^gondii tachyzoites was investigated by TUNEL (terminal\|deoxynucleotidyl transferase mediated d\|UTP nick end labeling ) method, electron microscopy and agarose gel electrophoresis. Results NO donor, sodium nitroprusside (SNP),was found to induce apoptosis in Toxoplasma gondii tachyzoites in a time\| and dose\|dependent manner by TUNEL detection. N\|acetylcysteine, a NO scavenger, could inhibit SNP\|induced apoptosis in the tachyzoites while potassium ferricyanide could not induce apoptosis in the tachyzoite. Electron macroscopy showed that SNP\|treated tachyzoites possessed typical morphological features of apoptosis, including chromatin condensation below the nuclear membrane, nuclear pyknosis, and formation of apoptotic body.Agarose gel electrophoresis revealed that SNP\|treated tachyzoite DNA fragment exhibited characteristic "DNA ladder" after 15 to 20 h. Conclusion SNP, NO donor, might induce apoptosis in T\^gondii tachyzoites in terms of characteristic morphological and biochemical features.

Aim To explore the effects of inhibitors of glycosphingolipid biosynthesis D-PDMP on the proliferation and differentiation of neural stem cells. Methods Neural stem cells cultured in vitro were treated with different concentration of D-PDMP. The effects of D-PDMP on proliferation and differentiation of neural stem cells were evaluated by counting of neurospheres size and cellular number, MTT assaying and the experiment of inducing differentiation.Results Neurospheres were smaller in size after treated with D-PDMP. The data of cellular counting and MTT assay suggested that D-PDMP could inhibit proliferation of neural stem cells and lead cells death in higher concentration, D-PDMP also reduced the differentiation ability of neural stem cells. Although differentiated cells were fewer, they could be induced into neurons and astrocytes.Conclusion The inhibitors of glycosphingolipid biosynthesis D-PDMP could inhibit the proliferation of neural stem cells, even lead cells death. It also reduced the differentiation ability of neural stem cells.

Objective To study the ultrastructure of neural stem cell neurosphere cultured in vitro. Methods Neural stem cell neurospheres from the rat brain were observed under transmission electron microscope or with stain of lanthanum nitrate, ruthenium red and tannic acid. Results The conjunction between the cells within neurosphere was loose and no tight junction was observed. Neural stem cells were proliferating lively. Some neural stem cells differentiated into cells with process and structure of axon, even showed the structures similar to myelin.Conclusion The ultrastructure of neural stem cell neurosphere cultured in vitro was revealed.

Although there is emerging evidence that BJ46a can function as potent inhibitor of the SVMPs proteolytic activities,its anticancer effect on invasion and metastasis has not yet been evaluated.Inhibition effect of BJ46a on experimental pulmonary metastasis in mice inoculated with B16 melanoma cells at the protein level was investigated. First,BJ46a was produced in baculovirus expression system. SDS-PAGE and Western blot analysis confirmed that BJ46a recombinant protein was produced by Sf9 cells infected with high-titer viral stock. Then,recombinant fusion protein was purified by ProBondTM at the point of maximal expression. B16 cells pre-treated with recombinant BJ46a injected into C57BL/6 mice via the tail lateral vein to form experimental pulmonary metastasis model. The numbers of metastatic lesions in C57BL/6 mice changed dramatically:BJ46a different concentrations of recombinant protein group were 1.1 ? 0.83,0.9 ? 0.7,significantly lower than the control group (6.3?3.00,P