Role of B cells in CD45RB antibody-induced transplantation immune tolerance

AIM: To investigate the role of B cells in CD45RB antibody-induced transplantation immune tolerance. METHODS: Single cell suspension was made from the spleen of BALB/c nude mice disposed by CD45RB antibody, then mixed cultured with T cells of BALB/c mice and spleen cells of C57BL/6 mice. The Th1, Th2, Treg and Tm cells were monitored by flow cytometry during the culture process. The skin graft model was set up with B6.μMT^-/- mice as receptors and BALB/c mice as donors. CD45RB antibody was intraperitoneally injected into the receptors after transplantation and then CD3⁺CD45RB^hi cells were detected by flow cytometry. In another mixed lymphocyte culture, CD45RB antibody was added, and then B cells were isolated and injected into B6.μMT^-/- mice through the tail vein. The heart transplantation model was established with B6.μMT^-/- mice as receptors and BALB/c mice as donors, and then the survival and the migration of B cells to the thymus were observed. RESULTS: When T lymphocytes were co-cultured with B lymphocytes treated with anti-CD45RB monoclonal antibody(mAb) in vivo, the percentages of Th2 and Treg cells were up-regulated and Th1 cells were down-regulated, but Tm cells were not altered as compared with the control. In vivo without B lymphocytes, anti-CD45RB mAb also down-regulated the expression of CD45RB in T lymphocytes. The reduction was faster and the percentage of CD3⁺CD45RB^hi T cells was not altered as compared with the control. The B lymphocytes treated with anti-CD45RB mAb in vitro prolonged the lifetime of receptor in heart transplantation model but failed to induce complete tolerance. After recieving B cells treated with anti-CD45RB mAb and allogeneic heart transplantation, B cells migrated to the thymus in B6.μMT^-/- mice. CONCLUSION: B lymphocytes play a definite role in the transplantation immune tolerance induced by anti-CD45RB mAb through their affection on T-cell subgroups and also in the central tolerance. However, the induction of immune tolerance can not only rely on B cells.     

A Regeneration System for Cotton Variety Xinluzao 45 via Somatic Embryogenesis

[Objective] The purpose of this study was to expand upland cotton genotypes suitable for regeneration via somatic embryogenesis, so as to provide excellent receptor materials for the genetic transformation of cotton. [Method] Six different hormone combinations were studied to establish a somatic embryo regeneration system for hypocotyl explants of Xinluzao 45, a widely planted variety in Xinjiang Province. [Result] Faint yellow callus was induced on a medium consisting of hormone combinations C1 (0.1 mg·L^－1 acetic acid dichlorobenzene oxide [2, 4-D] + 0.1 mg·L^－1 kinetin [KT]) or C5 (0.1 mg·L^－1 2, 4-D + 0.5 mg·L^－1 indo-3-butyric acid + 0.1 mg·L^－1 KT). The generated callus was able to successfully induce embryogenic callus on hormone-free medium containing doubled KNO3. The embryogenic callus then developed into somatic embryos and regenerated plants. Maximum rates of callus induction and regeneration were 92.2% and 40.3%, respectively. Although no significant difference was observed in the rate of callus induction of Xinluzao 45 hypocotyls between hormone combinations C1 and C5, the incidence of induced embryonic callus was higher on C1 than on C5. [Conclusion] The somatic embryo regeneration system developed in this study provides technical support that will facilitate Agrobacterium-mediated transformation of upland cotton Xinluzao 45.     

Effects of human bone morphogenetic protein 2 and 9 on proliferation,apoptosis and migration of human gastric carcinoma MNK-45 cells

AIM: To investigate the effects of human bone morphogenetic protein 2 (BMP2) and BMP9 on the proliferation, apoptosis and migration of human gastric carcinoma cell line MNK-45. METHODS: Immunocytochemical staining, MTT assay, wound-healing test, Transwells migration test, Hoechst 33258 staining and flow cytometry (FCM) were used to determine the infection of AdBMP2 and AdBMP9 on the proliferation, apoptosis and migration of MNK-45 cells. The expression of GSK-3β (including p-GSK-3β and total GSK-3β) and β-catenin in MNK-45 cells was also detected by Western blotting. RESULTS: The proliferation of MNK-45 cells was inhibited from the third day on and in a time-dependent manner after infected with AdBMP2 and AdBMP9. The results of Hoechst 33258 staining and FCM proved that apoptosis rates in BMP2 group and BMP9 group were higher than that in GFP group. Both wound-healing test and Transwell experiment indicated that up-regulating the expression of BMP2 and BMP9 inhibited the migration of MNK-45 cells. The phosphorylation levels of GSK-3β in BMP2 group and BMP9 group were higher than that in GFP group. However, no significant change of β-catenin among groups was observed. CONCLUSION: Up-regulation of BMP2 and BMP9 expression inhibits the proliferation of MNK-45 cells.     

不锈钢纤维/木纤维复合中纤板的研究

本文重点研究了不锈钢纤维的施加比率对钢/木纤维复合中纤板性能和电磁屏蔽效能的影响.结果表明,不锈钢纤维的施加比率对复合中纤板的力学性能影响显著;在钢/木混合纤维中施加一定量的异氰酸酯胶可显著改善中纤板的胶合性能并达到国标要求.不锈钢纤维的施加比率及其在中纤板中的复合位置对电磁屏蔽效能影响显著,当钢/木纤维混合比率为3:1并复合在中纤板的双侧表面时,其电磁屏蔽效能可达55 dB以上.     

细胞培养基MLM-45及培养条件对不同发育时期柞蚕卵巢细胞生长的影响

选择柞蚕5龄幼虫以及前滞育期、滞育期和解除滞育后发育前期、中期、后期的柞蚕蛹分离卵巢细胞,利用新研制的柞蚕细胞培养基MLM-45,在不同温度、pH值及渗透压条件下进行柞蚕卵巢细胞的体外培养,探究最佳培养条件及卵巢细胞取材的最佳发育时期。用台盼蓝染色活细胞计数方法,测定不同条件下用MLM-45培养基培养的不同发育时期柞蚕卵巢细胞的活力,当在27℃、pH 6.3、渗透压325 mOsm/kg的条件下培养30 d时,上述各发育时期柞蚕卵巢细胞的存活率最高,并且5龄幼虫、前滞育期和解除滞育后发育前期的卵巢细胞出现了增殖,其增殖率分别为54%、64%和2%,滞育期及解除滞育后发育中期和后期的卵巢细胞存活率也分别达到99.6%、96.6%和92.4%。在此最佳培养条件下,各发育时期柞蚕卵巢细胞培养2个月后其形态以圆形和椭圆形为主,尤以5龄幼虫和前滞育期蛹卵巢细胞的培养效果最好,细胞增殖7～8倍,是适于以MLM-45培养基培养的最佳发育时期柞蚕卵巢细胞。     

钢纤维混凝土在道路工程中的应用研究

钢纤维混凝土具有较高的抗拉强度和断裂韧性、抗疲劳等性能,适用于高等级公路路面、机场跑道、桥梁面层、工业建筑地面、复杂应力部位、铁路轨枕、局部增强预制桩等重要部位.同时钢纤维的外形,长度对钢纤维混凝土的性质有一定的影响,在施工时钢纤维混凝土的施工工艺与普通混凝土也有一定差异,本文针对上述问题进行了相关实验研究.     

现浇砼连续箱梁扣件式钢管支架的计算及施工

构造简单，安装方便，荷载作用下稳定性比较好的扣件式钢管支架，是目前桥梁施工中应用最广泛的一种支架。现就使用前在组合荷载作用下，格构式钢管支架整体稳定及单根钢管立杆局部稳定进行验算。安装时，支架立杆的纵距、横距及水平杆的步距要根据验算结果进行。安装顺序，立杆沿桥纵向由一端向另一端，水平杆由下向上进行。支架安装完成后，应做预压试验，以检查支架的压缩量及稳定性。     

45SrDNA在百萨偃麦草染色体上的分布

百萨偃麦草是小麦亲缘物种之一,对环境胁迫和生物胁迫具有很强的抗性,是小麦遗传改良的重要资源。为了对导入的百萨偃麦草染色体及片段进行有效鉴定,创造新种质。利用顺序分子原位杂交方法,研究了45SrDNA在百萨偃麦草染色体上的分布情况。结果发现45SrDNA在百萨偃麦草上有1对主位点,但在百萨偃麦草1J染色体上没有观察到45SrDNA位点的存在。     

耐热花椰菜“悦阳45天”的选育与栽培技术

悦阳45天是以9202自交系为母本、雪白48为父本杂交选育而成的松花型花椰菜新品种,经品比试验和示范试验,综合表现好,具有高产、优质、早熟、耐热、较抗黑腐病和软腐病等优点。从育苗、整地定植、田间管理、病虫害防治、盖花和采收等方面总结其高产栽培技术。     

猪带绦虫六钩蚴45W-4BX抗原的制备及其杂交瘤细胞株的建立

为获得针对猪带绦虫六钩蚴（TSO）45W-4BX抗原的杂交瘤细胞株,用IPTG对TS045W-4BX的重组质粒pGEX-4BX进行了诱导表达,并采用Sepharose-4B层析技术对表达产物进行纯化,运用SDS—PAGE和Western—blot分别对其纯度和活性进行了检测。分别用弗氏完全佐剂、弗氏不完全佐剂乳化已纯化的猪带绦虫TS045W-4BX重组抗原,随后用其分别免疫BALB／c小鼠3次,检测血清抗体效价呈阳性。之后,再进行加强免疫,取免疫小鼠脾细胞和SP2／0细胞进行融合,经TS045W-4BX抗原和GST抗原双系统间接ELISA筛选,最终获得了18株抗TS045W-4BX抗原的杂交瘤细胞株。采用有限稀释法对其中的4株进行5次亚克隆,最终获取了4株稳定分泌针对TS045W-4BX抗原的单克隆抗体的杂交瘤细胞株,金标试纸条法鉴定其抗体亚类均属于IgG1类,轻链为κ型。