Effects of mitochondrial ATP-sensitive potassium channel opener and hypoxic preconditioning on the hyperpolarization-activated current of sinoatrial node cells in neonatal rats

AIM: To compare the effects of hypoxic preconditioning (HP) and mitochondrial ATP-sensitive potassium (K_ATP) channel opener pretreatment on the hyperpolarization-activated current (I_f) in sinoatrial node cells.METHODS: Sinoatrial node cells were randomized to five groups: ① Control;②Hypoxia/reoxygenation (H/R);③ HP;④ Diazoxide (mitochondrial K_ATP channel opener)+H/R;⑤ 5-HD (mitochondrial K_ATP channel blocker)+HP.At the end of the experiment, I_f was recorded by whole-cell patch clamp technology.RESULTS: ①H/R significantly enhanced the current densities of I_f, shifted the current activation curve to more positive value by changing the half-activation voltage from (-98.9±2.4)mV to (-85.2±2.5) mV (P＜0.01).② Both diazoxide pretreatment and HP remarkably reduced the augmented current density caused by H/R and shifted the current activation curve to more negative value by changing the half-activation voltage to (-90.7±5.0) mV (P＜0.01) and (-92.2±1.9) mV (P＜0.01).③ 5-HD pretreatment blocked the effects of HP and reversed the half-activation voltage to (-86.3±2.7) mV (P＜0.01).CONCLUSION: The study demonstrates that both mitochondrial K_ATP channel opener pretreatment and HP make current density and kinetics of I_f to approach normal level and to maintain electrophysiological stability of sinoatrial node cells during H/R.     

Inhibitory effects of genistein on mouse allergic contact dermatitis

AIM: To investigate the inhibitory effects of genistein (Gen) on mouse allergic contact dermatitis (ACD). METHODS: The animal model of ACD was induced by DNFB. The effects of different doses of Gen on mouse ear swelling，body weight, histopathological changes in mouse ear skin, thymus index and spleen index were observed. RESULTS: All groups of Gen inhibited mouse ear swelling induced by DNFB significantly. The infiltration of inflammatory cells and thymus index were also reduced. However, the increase in mouse body weight was not affected. Low dose of Gen increased spleen index, high dose of Gen decreased spleen index. CONCLUSION: Genistein has significant inhibitory effects on mouse ACD induced by DNFB.     

Protective effects of ［Gly14］-humanin on cultured neural stem cells treated with β-amyloid protein in vitro

目的：研究［Gly14］-humanin对β淀粉样蛋白1-42引起的神经干细胞毒性的作用。方法：用［Gly14］-humanin和β淀粉样蛋白1-42处理神经干细胞，观察其对神经干细胞增殖、分化的影响。结果：较低浓度的［Gly14］-humanin加入有β淀粉样蛋白1-42处理的神经干细胞培养基，经过琼脂糖凝胶电泳分析及流式细胞测定DNA含量，神经干细胞显示出对β淀粉样蛋白1-42的耐受，而对照组则显示神经干细胞出现凋亡现象。高浓度的［Gly14］-humanin加入培养基，经台盼蓝拒染法计数细胞，神经干细胞死亡率明显低于对照组，对照组神经干细胞出现大量死亡。结论：［Gly14］-humanin 不但具有抑制β淀粉样蛋白1-42对神经干细胞的毒性作用，而且在低浓度的情况下，可以促进神经干细胞的增殖和分化为神经元。     

地高辛标记cDNA探针检测苹果茎痘病毒

 Partial sequence(314 bp) of ASPV was cloned and used as a probe labelled with digoxigenin-11dUTP. The total RNA extracted from samples with Apple stem pitting virus and a series of dilutions of plasmid with ASPV-cDNA were detected by dot blot hybridization. The results showed that the probe was sensitive and specific. The probe couldn't hybridize with total RNA of Apple stem grooving virus, Apple mosaic virus and Apple chlorotic leaf spot virus samples as well as negative control, only hybridized with that extracted from dormant shoot infected with ASPV. The sensitivity for detection of plasmid contained ASPV-cDNA was 1.64 μg.     

林木害虫刺桐姬小蜂风险分析

刺桐姬小蜂（Quadrastichus erythrinael Kim）是我国大陆新发现的有害生物，根据刺桐姬小蜂的国内分布状况、潜在经济危害性、寄主植物的经济重要性、传播扩散的可能性和危险性管理难度等方面对其进行了风险分析，结果表明刺桐姬小蜂为我国风险中度偏高的有害生物。作者提出了检疫管理及除治措施。     

胭脂蚧的形态特征及蜡泌物超微结构的研究

采用制作玻片标本和扫描电镜技术研究了胭脂蚧Dactylopius confusus（Cockerell）在不同发育阶段的显微形态特征及蜡泌物的超微形态。结果发现：1龄若虫，它的五格腺分布全身，管腺有少量分布；背刺为柱状或截锥状，呈带状分布。雌成虫，它的管腺分布整个腹面，五格腺在腹面末端成簇，在背面单个或成群分布；背刺散布全身。蜡泌物的研究发现：若虫背腹面均分泌丝状蜡，断裂后形成C型小蜡圈；背刺实为中空管，具泌蜡功能。雄茧是由蜡丝交织构成。雄蛹表面附着白色蜡粉。而雌成虫蜡被是由粗蜡管及其周围的细长蜡丝组成。     

苇状羊茅与多年生黑麦草内生真菌菌丝基因组DNA提取的优化及PCR初步检测

感染内生真菌的禾草在牧草和草坪业上具有重要的生态和经济意义，家畜采食感染Neotyphodium coenophialum和N.lolii的苇状羊茅和多年生黑麦草会发生中毒。本研究收集天津口岸1998年以来进境的部分苇状羊茅和多年生黑麦草种子，对经镜检确认带有内生真菌的种子进行分离培养，对疑似菌株的菌丝用改进的Moiler等方法进行基因组DNA抽提，测定浓度及纯度，对照原方法，DNA的纯度有较大提高，浓度略有上升。Tubulin2基因的引物IS1-IS3扩增结果显示为单一的条带，结合形态学和序列比对，分离培养得到的菌株可以基本确定为N．coenophialum和N。lolii。根据Genbank中N.coenophialum和N.lolii的NC25基因序列设计出引物F1-R1，扩增得到能区分开N.coenophialum和N．lolii的单一条带（相差160bp），建立了N．coenophialum和N．lolii的PCR检测方法，结果准确可靠。     

东亚飞蝗的长期预测预报技术研究

东亚飞蝗的发生面积、发生程度主要受残蝗面积、密度和降水条件的影响;库、湖蝗区的宜蝗面积主要受库、湖水位的影响。同时,东亚飞蝗的发生期主要受蝗卵发育期温度条件的影响。利用上述因子分别对东亚飞蝗的发生面积、发生程度及密度、3龄盛期进行预报,简便易行,准确可靠,时效性强,对指导防治工作十分有益。     

敌草胺·乙草胺防除油菜田杂草药效试验报告

50%敌草胺.乙草胺WP对油菜安全,对油菜田中的看麦娘等禾本科杂草和雀舌草等阔叶杂草有较好的防效。其施用适期为油菜移栽后、看麦娘2~3叶期,用100~120 g/667m2,对水45 kg/667m2均匀喷雾。