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Objective To investigate the effects of T. gondii soluble tachyzoite antigen (STAgs) on the survival time of mouse heart allograft and the possible mechanism. Methods The STAgs were prepared by pulverizing T. gondii tachyzoite with ultrasound on ice. Cervical heterotopic heart transplantations were done by using Balb/c mice as donors, and C57BL/6 mice as recipients.The recipients were classified randomly into three groups: syngeneic group, acute rejection group and STAgs-treated group. The recipients in acute rejection group and STAgs-treated group were injected subcutaneously with 0. 1 ml PBS and 0. 1 ml (5 μg) STAgs at the 4th day before transplantation respectively, and those in syngeneic group were not subjected to any treatment. The grafts were observed daily by cervical palpation, and the total cessation of cardiac contraction was defined as the endpoint. The heart allografts were harvested at the 7th day after transplantation for pathological examination and immunohistochemical staining for CD4+ T, CD8+ T. Results The recipients in syngeneic group were all alive at the 100th day after transplantation. The average survival time in acute rejection group and STAgs-treated group was (6.7± 0.5) days and (70.8± 3.5) days,respectively (P＜0.05). HE staining showed that the rejection on the 7th day after transplantation in syngeneic group, acute rejection group and STAgs-treated group was fallen into 0 degree, Ⅲ-Ⅳ degree and 0- Ⅰ degree, respectively. Immunohistochemical staining revealed that the CD4+ T and CD8+T were markedly down-regulated in STAgs-treated group as compared with those in acute rejection group. Conclusion T. gondii STAgs can significantly prolong the survival time of mouse heart allograft and inhibit the rejection probably by changing the ratio of TH1/TH2, or inhibiting the effect of dendritic cells by inducing the lipoxin A4.
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Objective To obtain M. Tuberculosis Ag85A protein by prokaryotic expression. Methods The fbpA gene encoding M. Tuberculosis Ag85A protein was amplified by polymerase chain reaction ( PCR) from M. Tuberculosis H37R_V strain. The PCR product was cloned into prokaryotic expression vector pProEXHTb to generate the recombi-nant plasmid pProfbpA, which was then transformed into the competence Escherichia coli BL21 cells. The recombi-nant Ag85A protein was successfully expressed by isopropyl thio-β-D-galactoside(IPTG) induction and purified by the Ni-purification system. The distribution of fbpA gene in different nonpathogenic mycobacterial strains was screened by PCR and ELISA was performed to determine the immunoreactivity of the recombinant Ag85A protein with serum from mice with mycobacterial infections. Results 32 ku Ag85A protein was successfully expressed and purified. It was confirmed by PCR and ELISA that fbpA gene presented in the genomes of M. Tuberculosis H37Rv, H37Ra, BCG, M. Smegmatis, M. Terra, M. Trivial and M. Phlei, but being absent in the genomes of M. Vaccae. The highest Ag85 A antibody titer was found in serum of TB patients and mice infected by M . Tuberculosis H37Rv .Conclusion The recombinant Ag85A protein was successfully expressed and purified.
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<p><b>OBJECTIVE</b>To investigate the effects of the metabolite produced by Trichomonas vaginalis on human sperm motility in vitro.</p><p><b>METHODS</b>Trichomonas vaginalis having been cultured, the culture solution containing metabolite was obtained by removing the protozoa, then diluted into 3 kinds of concentration. Sperm was obtained from 10 healthy fertile men by masturbation and prepared by swim-up technique to produce a spermatozoon solution of high motility. Every sperm sample was divided into 4 groups (A, B, C, D). Unused culture solution was added to Group A as control, and the other 3 groups (B, C, D) were respectively incubated with the above used culture solution at 3 kinds of concentration (1.2 x 10(9)/L, 6 x 10(8)/L, 1.2 x 10(8)/L). Measurements were carried out at 30 s, 1 h, 2 h, 4 h, 6 h by CASA.</p><p><b>RESULTS</b>Sperm motility decreased in both Group B and C markedly, and the effects displayed a concentration- and time-dependent manner.</p><p><b>CONCLUSION</b>The metabolite of Trichomonas vaginalis can reduce human sperm motility in vitro, and may be one of the causes of infertility.</p>
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Animals , Humans , Male , Dose-Response Relationship, Drug , Sperm Motility , Time Factors , Trichomonas vaginalis , MetabolismABSTRACT
Objective To study the in vitro larvicidal activity of nitric oxide (NO) to the juvenile Schistosoma japoni-cum. Methods Macrophages were induced by LPS or LPS + IFN-? to produce NO, schistosomula obtained mechanically from cercariae were added to the medium with activated macrophages, the larvicidal activity was observed within 48 h . In order to further confirm the effect of NO, an inhibitor of iNOS,L-NNA (N?-nitro-L-arginine), was used to inhibit the production of NO, larvicidal activity was measured by the same methods and the difference of dead larvae ratio was compared between the inhibited and uninhibited groups. Results LPS and LPS + IFN-? can induce macrophages effectively, with the NO production of (109.96?3.70)?mol/L and (113.50?7.38) ?mol/L respectively, accordingly the larvicidal effect reached to 91.07% ?2.92% and 96.86%?2.36% respectively. This activity can be inhibited by L-NNA. NO production and dead larvae ratio were reduced significantly in the inhibited group than in the uninhibited one. Conclusion NO produced by activated macrophages can kill schistosomula of Schistosoma japonicum.
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Objective To investigate the effect of nitric oxide on the liver fibrosis of mice infected with Schistosoma japonicum during the early stage of schistosomiasis. Methods NMRI mice were treated with AMG-an iNOS inhibitor from day 23 post infection(p.i) to the sacrificed and the livers were collected at 38 days, 45 days p.i respectively. The expression and distribution of collagen typeⅠ, Ⅲ (ColⅠand ColⅢ) in liver tissues were investigated with the Picric acid-Sirius red staining techniques and differentiated with the polarization microscopy combining with picture analysis system. Hydroxyproline concentration in liver homogenate was measured by the biochemical methods. Results At 38 day p.i, the Picric acid-Sirius red staining showed that the hyperplasia of Col Ⅰ and ColⅢ in the livers of AMG treated mice increased significantly compared with the control livers, but there was no significant difference of hydroxyproline content between the two groups. At 45 days p.i, only the hyperplasia of Col Ⅰ in AMG treated group increased significantly compared with the control livers, and moreover, content of hydroxyproline of the inhibited mice was significantly higher than that of the control mice (P