壳聚糖对黄瓜种子萌发和生长发育的影响

研究了壳聚糖对黄瓜种子萌发和生长发育的影响。结果表明，壳聚糖能促进种子萌发，改善根系的发育，增强超微弱发光强度和过氧化氢酶的活性，最适宜浓度为0.1%和0.05%。     

三种外检植物病毒的灭活处理

番茄环斑病毒（ＴｍＲＳＶ），烟草环斑病毒（ＴＲＳＶ），南芥菜花叶病毒（ＡｒＭＶ）的病汁液和ＰＥＧ粗提纯液，经适宜温度或甲醛处理，均丧失侵染性而有抗原性。ＴｍＲＳＶＰＥＧ粗提纯液经６０℃（水浴）处理１０分钟或２８℃７天，ＴＲＳＶ粗提纯液置２５℃一个月，Ａｒ－ＭＶ在４０℃７天条件下均可做为阳性对照的灭活处理的最佳方案。可保存抗原性在７～１２月以上。为了防止危险性检疫病毒的侵入，对入境种苗进行检疫，需建立快速、准确、标准化检疫程序，而在血清学快速诊断试验中，提供阳性对照，对提高判断准确率是必要的。因此，为了解决在诊断试剂中提供阳性对照但又不能使其检疫性病毒人为扩散这一重要问题，我们在研究三种外检病毒（ＴｍＲＳＶ，ＴＲＳＶ，ＡｒＭＶ）的检验技术的同时，又进行了一些灭活试验，用化学和物理方法钝化病毒，使其失去侵染性而保持抗原性，并应用于酶联诊断试剂盒中，本文报道了初步试验结果     

山羊传染性胸膜肺炎支原体和绵羊肺炎支原体对抗菌药物敏感性的研究

测定了环丙沙星、氧氟沙星、单诺沙星、红霉素、罗红霉素、泰乐菌素、泰妙菌素、四环素等8种药物对羊肺炎支原体两个标准株Y-98和Y-goat的体外抑菌浓度以及红霉素与氧氟沙星、泰乐菌素对Y-goat和四环素与氧氟沙星、泰乐菌素对Y-98的联合药敏作用.结果表明,这8种抗菌药物对Y-goat和Y-98的MIC(μg/mL)分别为:环丙沙星0.223、0.002 23,氧氟沙星0.281、0.014 0,单诺沙星0.136、0.014 0,红霉素0.021 8、无效,罗红霉素0.032 7、无效,泰乐菌素0.042 2、0.039 0,泰妙菌素0.021 7、0.052 0,四环素0.195、0.052 0.红霉素与氧氟沙星的联合药敏指数为1,是相加作用;红霉素与泰乐菌素对Y-goat的联合药敏指数为1.5,是无关作用;四环素与氧氟沙星、泰乐菌素对Y-98的联合药敏试验指数均为0.375,是协同作用.     

奶牛MTT比色法的最佳条件探讨

为建立奶牛淋巴细胞增殖反应MTT比色法,对试验条件进行了研究。应用L16(45)正交试验,对影响MTT比色法的四个主要因素,包括ConA浓度、细胞浓度、培养液小牛血清浓度及培养时间进行了比较和探索。试验表明几个因素对其增殖反应都有显著影响(P<0.05),且最佳反应条件为:15μg/mL的ConA、1×106/mL细胞浓度、10%小牛血清及60h的培养时间;影响增殖反应的先后顺序为细胞浓度、ConA浓度、培养时间及血清浓度。     

Comparison of different conditions inducing embryonic stem cells

AIM: To evaluate the different conditions inducing mouse embryonic stem cells (ESC) in vitro to differentiate into cardiomyocytes. METHODS: BRL conditioned medium was used to promote the growth of ESC and maintain them in an undifferentiated state. During the inducing process, retinoic acid (RA), DMSO, activin-A and TGF-β₁ were used as inducing reagents, and made up six kinds of differentiating medium. Then a three-step method inducing ESC cultured in hanging drops, in suspension and in plating was used to induce the differentiation of ESC. RESULTS: ESC were induced in vitro to differentiate into cardiomyocytes. Of all groups, the highest differentiating rate was observed in the group induced by activin-A (20 μg/L) and TGF-β₁ (2 μg/L). CONCLUSION: The inducing conditions including activin-A (20 μg/L) and TGF-β₁ (2 μg/L) is very valuable in inducing ESC differentiation into cardiomyocytes.     

Taurine reduced oxygen free radical production induced by homocysteine in electron transport chain and homocysteine inhibites taurine transporter in mitochondria membrane

AIM: To observe effects of homocysteine and antagonized effects of taurine on electronic leakage and free radical production in myocardial mitochondria. METHODS: Myocardial mitochondria of rat heart was isolated, and was broken by supersonic wave to prepare submitochondria. Recombinant of succinic acid cytochrome c reductase was prepared with mitochondria of porcine heart. They were co-incubated with homocysteine and/or taurine with various concentration. The H₂O₂ and O₂^- were determined by chemiluminescence methods. The taurine transporter of heart mitochondria and its propert, and effects of homocysteine on its function were studied with glass filter. RESULTS: Homocysteine stimulated oxygen free radical production in heart mitochondria, submitochondria, and succinic acid cytochrome c in a concentration-dependent manner. Although taurine itself did not affect oxygen free radical production, taurine did inhibit oxygen free radical production in mitochondria, submitochondria and succinic acid cytochrome c in a concentration-dependent manner. Taurine transporters of Na⁺-dependent were existed in mitochondria membrane. Homocysteine inhibited taurine transtport in mitochondria in a concentration-dependent manner. CONCLUSIONS: Taurine inhibited electronic leakage and oxygen free radical production induced by homocysteine in electron transport chain. There were taurine transporters in mitochondria membrane, and transport functions of taurine transporter were inhibited by homocysteine.     

Bone marrow mesenchymal stem cells are induced to differentiate into cardiomyocytes by hepatocyte growth factor in vitro

AIM: To explore a new method of hepatocyte growth factor (HGF) inducing bone marrow mesenchymal stem cells (MSC) to differentiate into cardiomyocytes. METHODS: Bone marrow MSC was cultured with DMEM media (10% fetal calf serum) 4-6 passages, and induced by HGF (10 μg/L) for 30 d. Automatical beating of the differentiated cells was observed daily with transverse microscopy, or under condition of 0.1% isoproterenol or cal-cium-deprived incubation. Specific cardiac myosin in the cells was indentified by immunochemistry. RESULTS: At 14-20 d of differentiation, bone marrow mesenchymal stem cells formed clones, in 10%-50% of which spontaneous beating cell-mass had come to continuously exist. Isoproterenol increased the beating rate and calcium-deprived media inhibited the beating. The cells were identified to be cardiomyocytes by expression of cardiac myosin heavy chain. CONCLUSION: HGF may induce bone marrow mesenchymal stem cells into cardiomyocytes with high efficiency, but the differentiating pathway of stem cells remains to be further studied.     

锌对雏鸭外周血T-淋巴细胞的影响

15 0只 1日龄天府肉鸭健雏随机分为 3组 ,分别喂给缺锌 (每千克日粮含 Zn 2 2 .9mg)、对照 (每千克日粮含 Zn10 0 mg)和锌中毒 (每 kg日粮含 Zn130 0 mg)日粮 7周或 4周 ,以酸性 - α-醋酸萘酯酶 (ANAE)染色法观测外周血 T-淋巴细胞的动态变化。结果锌缺乏组和锌中毒组雏鸭外周血 T-淋巴细胞的 ANAE阳性率显著低于对照组 (P<0 .0 1) ,表明锌缺乏或锌中毒可抑制 T-淋巴细胞的生成 ,降低其在外周血中的数量。本试验还对锌缺乏和锌中毒引起的外周血 T-淋巴细胞减少的机理进行了探讨     

3周龄断奶仔猪胰酶发育规律的研究

以 3周龄断奶仔猪为试验材料 ,研究了断奶对仔猪胰酶活性的影响。试验表明 ,3周龄断奶可以显著降低仔猪胰脏中胰淀粉酶、胰蛋白酶、胰糜蛋白酶和胰脂肪酶的活性 ,且在断奶后 2周继续维持断奶时水平。断奶降低了小肠内容物中胰淀粉酶和胰脂肪酶的活性 ,但空肠和回肠胰蛋白酶、胰糜蛋白酶的活性在断奶后并未下降。     

牛胎儿成纤维细胞分离与体外培养

本研究以 4 5d牛胎儿为材料 ,使用 0 .2 5 %胰酶 + 0 .0 4 %EDTA消化液 ,分离得到牛胎儿成纤维细胞 ,体外培养传代至第 2 8代。本实验描绘出牛胎儿成纤维细胞生长曲线 ,并发现α MEM是一种适合牛胎儿成纤维细胞生长的培养基。分离得到的牛胎儿成纤维细胞传至第 1 8代时核型仍然正常 ,冷冻、解冻后细胞可继续传代