Upregulation of neurokinin A levels by nerve growth factor in the experimental asthmatic guinea pig

AIM: To explore the regulatory mechanism of nerve growth factor (NGF) on neurokinin A in the experimental asthmatic guinea pig. METHODS: Radioimmunoassay was used to determine the alteration of neurokinin A levels in the lower respiratory tract and visceral sensory afferent sites while NGF was absent (inhalation of NGF antibody through nasal cavity) in the asthmatic guinea pig. RESULTS: The contents of neurokinin A in the trachea, bronchus, lung, C₇-T₅ spinal ganglia and the correspondent spinal dorsal horn, nodose ganglia and solitary nucleus area in the experimental asthmatic guinea pig with the absent of NGF in the respiratory tract were much lower than those in the asthmatic and control groups (P＜0.01). CONCLUSION: NGF upregulated the contents of neurokinin A in the lower respiratory tract and visceral sensory sites of the experimental asthmatic guinea pig, and both might be involved in the pathogenesis of asthma.     

引诱剂在综合防治桔小实蝇作用中的评估

以使用引诱剂为主 ,坚持在杨桃园挂引诱笼 2 - 3年后 ,大量降低田间桔小实蝇BactroceradorsalisHendel雄虫数量和卵的受精率 ,配合其它的综防措施 ,防效逐年提高。三个综防点试验实践表明 :杨桃每果虫口数 ,卵孵化率及受害果率大大降低 ,防效达 92 5%。对桔小实蝇的防治初见成效。     

内生拮抗枯草芽孢杆菌BS-2菌株的发酵条件

内生拮抗细菌BS 2菌株在以黄豆粉为原料的 3号培养基中生长速度快 ,发酵滤液对辣椒炭疽病菌的抑制作用强 ,菌液对辣椒果炭疽病的防效最好。培养基初始 pH值、培养时间、温度、通气量等对菌株生长及其抗菌物质的分泌有明显影响。结果表明 ,以黄豆粉培养基、初始 pH值 6 .7(灭菌后 )、2 8℃、培养 4 8h、并尽量增大培养通气量 ,为菌株的最佳发酵条件。     

采收时间对蜡蚧轮枝菌分生孢子的萌发及致病力的影响

将蜡蚧轮枝菌Vp菌株在PDA培养基上23℃黑暗培养,分别于第5、15、20、25、30天后采收。将不同时间采收的分生孢子置于2％葡萄糖培养液内培养,16 h后检测其萌发率,结果表明,采收于第5天和第15天的分生孢子萌发率分别达到89.76％和94.98％,显著高于采收于第25天(30.27％)和第30天(6.12％)的孢子的萌发率;在PDA培养基培养5 d和15 d的分生孢子在相同浓度下对温室白粉虱的致病力分别达到83.40％和74.44％,显著高于培养了30 d的分生孢子的致病力(8.76％)。     

Effect of EGFP gene transfection on the cell cycle distribution of primary cultured human chondrocytes

AIM: To investigate the effect of enhanced green fluorescence protein (EGFP) gene transfection on the cell cycle distribution of primary cultured human chondrocytes in order to establish a tracking method of cultured human nasoseptal chondrocytes. METHODS: pEGFP-N1 plasmid was amplified in E.coli, and purified by high purity kit. Primary cultured human chondrocytes,which were initially obtained from the nasoseptal cartilage, were cultured in vitro and transferred with pEGFP-N1 by means of electroporation with Amaxa nucleofector device. Transfering process and transient expression were evaluated by laser scanning confocal microscope (LSCM), the transfer efficiency and the cell cycle distribution were evaluated by flow cytometry. RESULTS: There was significant expression of EGFP at 24 h after transferring. The transfection efficiency of pEGFP-N1 into primary cultured human chondrocytes reached 35.37％ at 48 h. It didn't affect the process of cell adherance and had no effect on the cell cycle distribution. CONCLUSION: Primary cultured human chondrocytes, which were transfected with pEGFP, are alive in vitro, and the transferring process doesn't affect the cell cycle distribution. These results suggest that pEGFP-N1 is an ideal transient expression vector for primary cultured human chondrocytes and it might be a well tracer in construction tissue engineered cartilage.     

家鸡Leptin成熟肽cDNA的克隆、重组蛋白表达及纯化

从 18周龄鸡卵巢组织中抽提总 RNA,使用六聚体随机引物反转录后 ,用鸡 L eptin(瘦素 )特异性引物扩增出鸡L eptin编码区第 5 2～ 4 6 0 bp的长度为 4 0 9bp的 c DNA片段。根据鸡 L eptin的 3′端第 4 6 0～ 4 92 bp序列设计了 3条部分相互重叠并且顺序串联延伸的下游反义引物 ,并在最后 1条引物 3′端连接上 Eco R 切点 ;在以上用于反转录扩增的 5′端引物的 5′端连接一 Bam H 切点。用该 5′端引物分别与 3个 3′端引物配对 ,利用反转录扩增出的 4 0 9bp的L eptin c DNA片段作为第 1模板进行扩增 ,扩增产物再作为模板与下一引物对再次扩增。经 3次扩增得到编码鸡 L ep-tin成熟肽的全长 4 5 1bp的 c DNA序列。将该 4 5 1bp的 L eptin c DNA序列经 Bam H 和 Eco R 双酶切后 ,克隆入表达质粒 p RSET A的 Bam H 和 Eco R 两酶切位点之间 ,构建成表达质粒 p L ep- SCAU。转化有重组表达质粒 p L ep-SCAU的大肠杆菌 BL 2 1(DE3)在 L B培养基中培养后 ,经 IPTG诱导表达出相对分子质量为 2 0 10 0的鸡 L eptin融合蛋白和少量 4 0 2 0 0的 L eptin融合蛋白。L eptin融合蛋白的表达在 IPTG浓度为 0 .0 5 mmol/ L 时达到最高 ,占总菌体蛋白的 32 .6 %。用 Ni- NTA凝胶从 7L 发酵培养菌裂解液中纯化出 180 m g左右     

水牛精子在胞质内注射后的早期形态变化

应用胞质内精子注射 (intracytoplasmic sperm injection,ICSI)技术探讨了水牛卵母细胞胞质与注射精子间的相互作用以及 ICSI精子的形态变化。ICSI后 13h,5 9.4 %的精子头部已膨大 ,且有 18.8%的精子进入解聚状态。雌雄原核发育不同步 ,雄原核在 ICSI后 16 h和 19h的形成率分别为 3.2 %和 4 0 .0 % ;雌原核在 ICSI后 13h已达到 71.9% ,16 h时提高到 90 .3%。经离子霉素与 6 - DMAP联合激活 ,ICSI后 19h产生的胚胎核型以 2 PN PB1 为主 ,其雌原核形成 (激活 )率为 91.3% ,雄原核形成率为 4 0 .0 % ,5 1.3%为孤雌胚。用 5 mm ol/ L 的 DTT预处理精子 1h,可提高精子的解聚率 (30 .9%比 12 .7% ,P<0 .0 5 ) ,但对雄原核的形成率无显著影响 (33.3%比 32 .7% ,P>0 .0 5 )。结果表明 ,水牛精子 ICSI后的雄原核形成时间晚于卵子雌原核形成时间 ,且其比率低于卵子 ,DTT处理精子能提高其解聚率 ,但对雄原核形成无影响     

几种脲酶抑制剂对大豆脲酶和绵羊瘤胃微生物脲酶的抑制作用

本文研究了脲酶抑制剂乙酰氧肟酸 (AHA)、邻苯二酚、氢醌 (HQ)和硼砂对大豆脲酶和绵羊瘤胃微生物脲酶的抑制作用。结果表明 ,在浓度为 0 .0 0 0 1,0 .0 0 1,0 .0 1和 0 .1mmol/L时 ,4种脲酶抑制剂对大豆脲酶的抑制率分别为 :AHA为 6 % ,6 .2 % ,9.6 6 %和 2 9.79% ;HQ为 8.4 % ,13.0 3% ,19.79%和 4 4 .75 % ;邻苯二酚为 2 0 .34% ,19.12 % ,83.16 %和 93.78% ;而硼砂为 16 .5 5 % ,17.18% ,18.95 %和 35 .5 0 %。在相同浓度下 ,4种脲酶抑制剂对绵羊瘤胃微生物脲酶的抑制率分别为 :AHA为 9.5 8% ,14 .0 4 % ,4 1.30 %和 72 .73% ;HQ为 12 .2 1% ,39.99% ,6 4 .6 2 %和 78.87% ;邻苯二酚为 6 .0 7% ,9.36 % ,31.2 9%和 5 0 .4 4 % ;而硼砂分别为 4 .97% ,8.6 3% ,2 1.78%和 32 .0 2 %。     

昆虫抗菌肽生物学活性及其应用前景

昆虫抗菌肽是昆虫免疫后存在于血淋巴中的一类活性肽 ,具有广谱的抗菌、抗病毒、抑制肿瘤的生物活性 ,具有很高的应用潜力。本文主要介绍昆虫抗菌肽的类型、生理活性、基因的克隆与表达及在动物科学中的应用前景     

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。