山豆根多糖体外清除自由基作用的研究

采用邻二氮菲-Fe2 氧化法测定了山豆根多糖(SSP1)清除羟自由基(.OH)的作用,应用邻苯三酚自氧化反应体系为产生超氧阴离子自由基(O2.)模型观察了SSP1对超氧阴离子的清除作用,选择辣根过氧化物酶-酚红法测定了山豆根多糖对H2O2的清除作用.结果表明,山豆根多糖(50～400 mg/l)具有清除羟自由基的作用,且呈明显的量效关系;对邻苯三酚自氧化具有抑制作用,对调理酵母多糖诱导的小鼠脾脏淋巴细胞释放H2O2具有抑制作用.该结果提示山豆根多糖具有抗氧化作用.     

富铁酵母对家兔红细胞免疫功能的影响

为探讨富铁酵母对家兔红细胞免疫功能的影响,将32只家免随机分成富铁酵母高、低剂量组,FeSO4组及空白对照组,分别灌服富铁酵母(Fe元素8 mg/kg、4 mg/kg)、FeSO4(Fe元素4 mg/kg)及空白生理盐水;连续5 d后,检测红细胞C3g受体花环率和复合物(IC)花环率.结果:富铁酵母较FeSO4及空白组能显著提高红细胞C3h受体花环和红细胞复合物(IC)花环的百分率,但高、低剂量间无显著性差异.结论:富铁酵母能显著提高红细胞免疫功能.     

差量法测定猪回肠AA的真消化率及内源AA的排泄量

本文探讨了采用差量法测定猪对豆粕氨基酸(AA)的消化率和内源氨基酸排泄量的可行性.试验测得豆粕在16%、10%日粮蛋白水平上的表观氨基酸消化率分别为81.84%、78.59%,以差量法求得真消化率为87.87%.研究结果表明,差量法可以作为测定猪氨基酸真消化率和内源氨基酸排泄量的新方法.     

猪大肠杆菌水肿毒素SLT-IIeA基因的克隆和序列分析

研究以本地猪水肿病大肠杆分离物ED1株为材料 ,利用 PCR克隆了含猪水肿病大肠杆菌 (VTEC) slt-IIe A基因 987bp的片段 ,并测定了含该克隆片段的 Bam HI、Hind 酶切片段的核苷酸序列。结果表明 ,slt-IIe A基因的编码区全长 960 bp,编码 3 1 9个氨基酸的蛋白质 ,序列与国外报导的 S1 1 79株进行比较发现其核苷酸同源性为 98.9%。经推导的氨基酸序列的同源性为 99.7%。这为进一步研究 slt-IIe A的生物学特性、水肿病的分子诊断及其防制打下基础     

玉米螟赤眼蜂对亚洲玉米螟种群的控制作用

为了解决深圳特区甜玉米产区日趋严重的农药污染问题,笔者在深圳龙岗生态示范农场甜玉米地研究了玉米螟赤眼蜂Trichogramma ostriniae的应用技术,分析了玉米螟赤眼蜂释放量、释放次数对亚洲玉米螟Ostrinia furnacalis Guen6e控制作用的关系,提出了最件释放方法.     

Regulation of MMP-2 and TIMP-3 expression by uPA signal transduction system in human bone giant cell tumor

AIM: To study effects of urokinase-type plasminogen activator (uPA) signal transduction on expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-3 (TIMP-3) in giant cell tumor of bone (GCT). METHODS: Expression of uPAR, MMP-2 and TIMP-3 in GCT tissue was detected by immunohistochemistry. Phosphorylation level of mitogen-activated protein kinase (p44) in uPA/uPAR signal pathway in cultured GCT cells was detected by immunoprecipitation. The expression of MMP-2 and TIMP-3 in cultured cells after treatment with uPA-ATF or anti-uPAR antibody was also detected by Western blotting. RESULTS: 1) Urokinase-type plasminogen activator receptor (uPAR) was positive on the cell membrane and in cytoplasm of some mononuclear stromal cells (MSCs) and multinucleated giant cells (MGCs); 2) MMP-2 was positive in the cytoplasm and on the cell membrane of almost all of MSCs and some of MGCs. The polar distribution of MMP-2 in the cytoplasm of MGCs was especially obvious; 3) The expression of TIMP-3 of some MSCs and MGCs in GCT was much lower than MMP-2. The positive signal also showed a prominent polarity; 4) After treatment with uPA-ATF, the phosphorylation level of p44 in GCT cultured cells was much higher than the control. Addition of anti-uPAR antibody in the cells remarkably down-regulated the phosphorylation level of p44 as compared with the control group, suggesting that uPA-ATF participates cell signal transduction and this reaction can be inhibited by anti-uPAR antibody; 5) uPA-ATF cell signal pathway up-regulated expression of MMP-2 and TIMP-3, while anti-uPAR antibody down-regulated the expression of MMP-2 and TIMP-3. CONCLUSION: These results demonstrate for the first time that uPA-ATF directly regulates the expression of MMP-2 and TIMP-3 by signal transduction pathway, and the over-expression of MMP-2 and TIMP-3 may play an important role in local osteolysis of GCT.     

百合病毒病的发生与症状类型

百合病毒病症状类型可归纳为7种类型,轻花叶型(Mm),重花叶型(Sm),矮化型(Stu),丛簇矮化型(Rstu)。黄化矮化型(Ys),扁茎簇叶型(Fsbl),花变叶型(Phy),其中轻花叶型和重花叶型发生普遍,花变叶型出现较少。病害发生的轻重与种球种龄有关,种龄越大,发病越重。前茬种植百合的地块较种植小麦的地块发病重,低洼积水地发病重。不同百合品种对病毒病的抗性有差异。     

几种绿色饲料添加剂在肉鸡生产上的应用效果

选1日龄AA肉鸡390只,分成13组,分别添加不同种类和不同种类组合的绿色饲料添加剂。试验结果表明,益生素能显著(p<0.05)提高肉鸡的生产性能,改善肉品质。     

浅论优质牧草在肉牛饲养中的利用

针对我国肉牛饲养在饲料利用中的误区,结合肉牛的消化及代谢特点,分析了牧草的鲜喂、青贮、干草饲喂以及综合利用4种不同的利用方式及其营养特点,指出优质牧草用于肉牛饲养能充分发挥牧草的优良特性,而且符合我国畜牧业发展要求,值得广泛推广.     

陕北黄土丘陵区撂荒演替研究一撂荒演替序列

用系统聚类法划分陕北黄土丘陵区撂荒地的次生演替阶段，可以定量的认识不同年限、立地条件下撂荒地群落的相似性，结合DCA数量排序确定撂荒地的演替阶段或序列。其撂荒演替的各阶段分别为：一年生杂类草猪毛蒿（Artemisia scoparia）＋其它杂类草群丛→一年生杂类草猪毛蒿群丛→一年生杂类草猪毛蒿＋多年生草种或小灌木的共优群丛一根茎禾草冰草（Agropyroncristatum）群丛→多年生草本或丛生禾草＋一年生杂类草群丛→多年生草本群丛→小灌木达乌里胡枝子（Lespedeza davurica）群丛→多年生草本＋小灌木或密丛型禾草群丛→短根茎密丛型禾草白羊草（Bothriochloa ischaemum）群丛。