去势和热应激对筠连黄牛生产性能、瘤胃发酵和血液生化指标的影响

为研究去势和热应激对筠连黄牛生产性能、瘤胃发酵和血液生化指标的影响,本研究选用18头16月龄、体重相近((292.35±28.71) kg)的不同去势程度筠连黄牛(全去势FCG、半去势HCG、假手术SOG),分为3组,每组6个重复,每个重复1头牛,根据试验期间牛舍温湿度指数(THI),分为热应激期(7、8月)和非热应激期(9月),分析去势和热应激对黄牛各指标的影响。结果表明：1)与非热应激期相比,热应激期牛舍THI、肉牛呼吸频率和直肠温度均显著提高(P<0.05)。2)去势和热应激均显著提高血清热休克蛋白70、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)和雌二醇浓度(P<0.05),而睾酮、甲状腺素(T4)、胰岛素和游离脂肪酸浓度显著降低(P<0.05),且除血清葡萄糖、T4和LDL-C外,去势和热应激对其他血清指标存在显著互作效应(P<0.05)。3)全去势和热应激均显著降低肉牛平均日增重(ADG),且存在显著互作效应(P<0.05)。4)热应激期,去势显著降低粗蛋白、酸性洗涤纤维和钙表观消化率以及血清总抗氧化能力(T-AOC)(P<0....     

Overexpression of SSTR2 inhibits growth of SSTR2-positive tumors via multiple signaling pathways

AIM: To study the anti-proliferation effect of overexpressed SSTR2 in experimental cancer with different profiles of endogenous SSTRs expressions and the possible signaling pathways involved. METHODS: In the first experiment, the growth of the tumor xenografts of the inoculated capan-2 cells and A549 cells overexpressing SSTR2 or LacZ was investigated in nude mice. In the second experiment, the adenoviral vector expressing SSTR2 were introduced into experimental capan-2 xenografts by intratumoral injection. The growth inhibition of these experiment tumors was observed and the potential influences on different signaling pathways were analyzed by immunoassays. RESULTS: Overexpression of SSTR2 inhibited the growth of tumors with different profiles of endogenous SSTRs, including experimental capan-2 xenografts that had endogenous SSTR2 expression. Overexpression significantly affected a number of components in apoptotic pathway, MAPK pathway and angiogenesis. CONCLUSION: SSTR2 is a promising candidate for gene therapy in a wide spectrum of cancers.     

Jagged1 knocking down in endothelial cells accelerates PDGF induced proliferation and migration of vascular smooth muscle cells in rats

AIM: To investigate the effect of Jagged1 expression in endothelial cells (EC) on platelet derived growth factor (PDGF) induced proliferation and migration of vascular smooth muscle cells (VSMC) in rat.METHODS: Rat aorta EC was inoculated in the lower chamber and VSMC were in the upper chamber of the cell coculture system. Three groups were divided: control, sicontrol and siJagged1. The EC Jagged1 protein expression was assayed by Western blotting to evaluate small RNA interfering (RNAi) efficiency. After the cells were cocultured with PDGF for 24 h, the proliferation and migration of VSMC were respectively evaluated by ［3H］-TdR incorporation and migrating cells counting. Protein expression of α-SM-actin in VSMC was assayed by Western blotting. RESULTS: The Jagged1 protein expression in EC was significantly lower in siJagged1 group than that in control group (0.26±0.02 vs 0.67±0.02, P<0.05), and no statistic significance was observed between control and sicontrol groups. The VSMC ［3H］-TdR incorporation and migration were higher in PDGF +siJagged1 group than those in PDGF group {［3H］-TdR incorporation (23 074±2 702) counts·min-1·well-1 vs (16 442±1 803)counts·min-1·well-1, n=5, P<0.05; migration (27±4) cells/field vs (15±3)cells/field, n=5, P<0.05}. The α-SM-actin protein in VSMC was lower in PDGF + siJagged1 group than that in PDGF group (0.25±0.06 vs 0.49±0.04, n=3, P<0.05).CONCLUSION: Jagged1 knock down in rat EC accelerates PDGF induced proliferation and migration of VSMC. These results suggest that Jagged1 expression in EC plays an important role in maintaining VSMC contract phenotype and inhibiting VSMC overgrowth after arterial injury.     

番茄晚疫病抗病育种及分子生物学研究进展

对国内外近年来在番茄晚疫病菌的病原学、抗病资源的筛选鉴定、抗病机制的研究及分子生物学方面取得的进展进行了综述,并展望了今后的研究重点和方向。     

雨季不同时段蒋家沟泥石流侵蚀产沙特征的分析

根据雨季不同时段,降雨入渗后的土壤含水状况观测以及泉水季节性变化,详细分析了蒋家沟1987-2001年雨季不同时段的167场泥石流侵蚀产沙的特点。结果表明:在雨季中期(7-8月),无论是泥石流暴发频率、产沙量还是规模都是最高值,分别占总样本的70.65%和占总产沙量的78.88%。雨季初期(5-6月)和雨季后期(9-10月)的泥石流,分别占总产沙量的16.16%和4.97%。雨季初期5月的雨沙比(R/s,mm/万m3)高达82.26,6月为3.49;而雨季中期的7月R/s仅为1.32,8月为1.67。这一研究可提高雨季不同时段泥石流降水警戒值确定的精度。     

面筋蛋白的胃蛋白酶酶解物对大鼠免疫功能的影响

选用 5 0只SD大鼠 ,分为试验组和对照组 ,每组 2 5只 ,试验组用经氯化钠缓冲液洗涤法制备的面筋蛋白的胃蛋白酶酶解物灌喂 ,对照组灌喂未经酶解的面筋蛋白 ,连续灌喂 2 1d。实验结果显示 :与对照组相比较 ,大鼠胸腺和脾脏相对重量分别上升了 2 0 % (P <0 0 1)和 2 9% (P <0 0 1) ;腹腔巨噬细胞吞噬活性上升了 12 % (P >0 0 5 ) ;淋巴细胞转化实验中刺激指数 (SI)提高了 33 0 % (P <0 0 5 ) ;血清NDV (新城疫病毒 )抗体血凝抑制效价 (HI)上升了 38 5 % (P<0 0 1) ;肠腔sIgA水平提高了 2 8 6 % (P <0 0 5 ) ;血清IL 2水平上升了 38 4 % (P <0 0 1) ;血清瘦素、胰岛素、T3 和T4水平均无显著变化。实验结果提示 :灌喂面筋蛋白胃蛋白酶酶解物能够增强机体免疫功能 ,并且这种免疫增强作用与细胞因子的调理有较为密切的联系。     

核桃细菌性疫病菌的特性及其与核桃内生菌的竞争

为了明确从湖北省丹江口市核桃病幼果上分离到的一株核桃细菌性疫病菌DW3F3的基本形态、生理生化特性、致病性相关特征以及与寄主内生菌的互作关系,对该病原菌进行了显微观察、生物膜形成测定,不同培养基上多糖和色素含量测定,18项生理生化指标测定,通过毛细管法和滴落法观察其趋化作用,并测试其与寄主内生菌的竞争能力。结果表明,病原菌DW3F3为杆状,极生鞭毛,有运动性,能形成生物膜。DW3F3在YPGAI、King's B和NA培养基上生长较好,而在NYG、PDA和LB培养基上产生多糖和色素较多。DW3F3有较强的耐盐性,致死温度达60℃,对纤维素和淀粉都有较强的分解能力,对HCl、NaCl和寄主叶片表现出一定的趋性。在与核桃叶部内生菌的共培养中,DW3F3表现出一定竞争优势。DW3F3有树生黄单胞菌核桃致病变种(Xanthomonas arboricola pv.juglandis,Xaj)的基本特征及致病相关特性,这些特征可能与其致病性强及病害难以控制有关。     

高效液相色谱法测定花生仁中甲咪唑烟酸残留

目前花生仁中甲咪唑烟酸残留量的检测是参考国标中茶叶农残的方法,花生仁基质含有大量的油脂和蛋白质,这与茶叶基质有显著区别,且该方法只能定性。本文建立了一种高效液相色谱法定量检测花生仁中甲咪唑烟酸残留量的方法。花生仁样品采用乙腈溶液提取后再经过除脂净化处理,以乙腈:0.02mol/L磷酸二氢钾缓冲液(加入0.1%的三乙胺,磷酸调pH3.0)体积比1:3作为流动相进行高效液相色谱紫外检测器分析。结果表明:甲咪唑烟酸标准在0~1.2mg/L范围内线性关系良好(R2=0.9999),检出限为7μg/kg;加标回收率为91.1%~98.9%;精密度、重复性、稳定性都较好。该方法操作简便、分离度好、结果准确,能很好地满足花生仁中甲咪唑烟酸残留量检测的要求。     

膳食纤维杂粮面包的研制

本试验以绿豆皮粉、黄豆皮粉、红薯皮粉、高筋面粉为主要原料,采用二次发酵法研制膳食纤维杂粮面包,通过口感和外观考察了配方和烘培时间对其风味品质的影响。结果表明,对杂粮面包品质的影响因素依次为改良剂添加量>杂粮皮粉用量>烘焙时间>酵母添加量。通过单因素和正交试验得到杂粮面包的最佳配方为高筋粉50%、杂粮皮粉2.3%(绿豆皮粉:黄豆皮粉:红薯皮粉=3:2:5)、白糖13.1%、酵母0.4%、改良剂0.2%、奶粉0.3%、水21%、鸡蛋6.6%、盐0.5%和黄油5.2%,烘培20min得到的杂粮面包的风味品质最佳,形态丰满完整,色泽均匀,组织有弹性,具有发酵烘烤后特有的面包香味,松软可口。     

苗药红禾麻野生与引种药材UPLC指纹图谱研究

采用超高效液相色谱法,探寻建立苗药红禾麻药材的UPLC指纹图谱测定方法,并比较分析野生与引种药材之间的指纹图谱差异。结果表明,不同红禾麻原产地药材指纹图谱相似度结果为0.212~0.769,存在明显的产地差异;每个野生药材与对应的引种药材的指纹图谱相似度计算结果大部分在0.75以上。建立的红禾麻指纹图谱方法快速、特征性强、重复性好,可用于红禾麻药材的整体质量评价。红禾麻野生药材之间、野生与对应引种药材之间的指纹图谱差异,表明环境因素影响其化学成分的变化。