黑缘烟蟋螽丝腺结构

【目的】蟋螽是直翅目中唯一具有吐丝筑巢行为的类群。本研究旨在探讨蟋螽丝腺的结构特点。【方法】应用解剖学观察、免疫荧光、苏木精-伊红染色、PAS苏木精染色、扫描电镜和透射电镜等方法从细胞水平对黑缘烟蟋螽Capnogryllacris nigromarginata丝腺的显微与超微结构进行了观察。【结果】黑缘烟蟋螽丝腺由导管和腺泡构成。腺泡由鞘细胞延伸形成的结缔组织鞘包围。腺泡的主体有4种细胞,分别为Ⅰ型分泌细胞、Ⅱ型分泌细胞、围细胞和腔细胞。Ⅰ型和Ⅱ型分泌细胞为大的腺细胞,形状不规则。分泌细胞细胞核很大,胞质内有大量的内质网和分泌颗粒。Ⅰ型分泌细胞靠近腺泡中心,PAS-苏木精染色表明Ⅰ型分泌细胞内含糖蛋白,Ⅱ型分泌细胞在腺泡外周,位于Ⅰ型分泌细胞与围细胞或结缔组织鞘之间。腔细胞分散在分泌细胞之间,包围形成胞外运输分泌物的通道。围细胞与鞘细胞接触,具有由细胞膜内陷形成的微绒毛腔,胞质内有大量的线粒体。围细胞微绒毛腔与腔细胞包围的细胞外运输通道相连,分泌细胞分泌的颗粒聚集在分泌细胞和胞外运输通道之间的连接处,并将分泌物排出至胞外运输通道。多个腺泡的胞外运输通道汇集到由单层细胞组成的丝腺导管。单层导管细胞靠近管腔外围具有规则排列的质膜内陷和大量伸长的线粒体;靠近管腔的一侧具连续的细胞膜突起,在导管壁的表皮下紧密排列。【结论】黑缘烟蟋螽丝腺分泌细胞分为Ⅰ型分泌细胞和Ⅱ型分泌细胞。分泌物质产生及分泌过程依次经过分泌细胞、腔细胞包围的胞外通道、分支导管、总导管和唾窦。其中在腺泡细胞之间,分泌物向外运输过程中,围细胞微绒毛腔的微丝束可能对分泌物的外排提供推动力。     

Selenium Attenuates Adriamycin-Induced Cardiac Dysfunction via Restoring Expression of ATP-Sensitive Potassium Channels in Rats

The possible mechanism of adriamycin (ADR) and/or selenium (Se) deficiency-induced cardiac dysfunction, and cardioprotective effects of Se against ADR-induced cardiac toxicity were investigated in this study. Cardiac function was evaluated by plasma brain natriuretic peptide level and echocardiographic and hemodynamic parameters. Cardiac glutathione peroxidase (GPx) activity was assessed spectrophotometrically. Expression of ATP-sensitive potassium channels (K_ATP) subunits—SUR2A and Kir6.2—were examined by real-time PCR and Western blotting. The results showed that cardiac function and cardiac GPx activity decreased remarkably after administration of ADR or Se deficiency; more dramatic impairment of cardiac function and cardiac GPx activity were observed after co-administration of ADR and Se deficiency. Mechanically, it is novel for us to find down-regulation of K_ATP subunits gene expression in cardiac tissue after administration of ADR or Se deficiency, and more significant inhibition of cardiac K_ATP gene expression was identified after co-administration of ADR and Se deficiency. Furthermore, cardiac toxicity of ADR was found alleviated by Se supplementation, accompanied by restoring of cardiac GPx activity and cardiac K_ATP gene expression. These results indicate that decreased expression of cardiac K_ATP is involved in adriamycin and/or Se deficiency-induced cardiac dysfunction; Se deficiency exacerbates adriamycin-induced cardiac dysfunction by future inhibition of K_ATP expression; Se supplementation seems to protect against adriamycin-induced cardiac dysfunction via restoring K_ATP expression, showing potential clinical application in cancer chemotherapy.     

A metabonomic investigation of the effects of 60 days exposure of rats to two types of pyrethroid insecticides

Type I and II pyrethroid insecticides display different neurotoxicity. To investigate the long-term (60 days exposure) metabolic effect of the two types of pyrethroid insecticides deltamethrin and permethrin, ¹H nuclear magnetic resonance (NMR) spectroscopy-based metabonomics was used to analyze the biochemical composition of urine and serum samples from rats administrated daily with deltamethrin or permethrin for 60 consecutive days, and principal component analysis used to visualize similarities and differences in the resultant biochemical profiles. Rats treated with either deltamethrin or permethrin displayed increased levels of urinary acetate, dimethylamine, dimethylglycine, trimethylamine and serum free amino acids, and decreased urinary 2-oxoglutarate, all of which are indicative of kidney lesions and nephrotoxicity. The reduced excretion of tricarboxylic acid cycle intermediates, together with increased 3-D-hydroxybutyrate, acetate, and lactate in treated rats could suggest disturbance of the energy metabolism, including an increased rate of anaerobic glycolysis, enhanced fatty acid β-oxidation and ketogenesis. These results show that these two types of insecticides have similarities in the urine and serum spectra, indicating that similar metabolic pathways are perturbed by the insecticides, which induced hepatotoxicity and nephrotoxicity. This approach may lead to the discovery of novel biomarkers of pyrethroids toxicity and thereby provide new insights into the toxicological mechanisms of pesticides pyrethroids.     

化学诱变剂EMS对知母种子萌发的影响

以知母（Anemarrhena asphodeloides）种子为材料,分别采用1%、2%、4%、6%浓度的EMS处理6、8、12和24 h,在恒温培养箱内进行种子萌发实验,研究不同浓度的化学诱变剂甲基磺酸乙酯（ethyl methane sulfonate,EMS）处理对知母种子萌发的影响,筛选适宜的诱变浓度和诱变时间。结果表明：随EMS浓度的增加和处理时间的延长,知母种子发芽率呈现逐渐降低的趋势,以相对发芽率达到半致死浓度为标准,6%EMS浸种12和24 h可作为EMS诱导知母建立突变体库的适宜条件。     

超临界CO2提取甘草地上部分总黄酮

采用单因素试验对甘草地上部分（茎叶）的超临界CO₂提取工艺进行了研究。实验考察了压力、萃取时间、温度及CO₂流量对甘草地上部分总黄酮提取率的影响,以总黄酮提取率和含量为指标,系统的研究了超临界二氧化碳萃取法提取甘草地上部分总黄酮的提取效果。得出的最佳工艺参数为：采用40~60目原料,80%乙醇为夹带剂,萃取时间：1.5 h;萃取压力：30.0 MPa;萃取温度：50℃;CO₂流量：10 kg·h^-1;分离压力: 5.8 MPa;分离温度: 40℃。实验结果表明超临界二氧化碳萃取甘草总黄酮的提取率2.09%,含量5.42%,工艺具有提取率高,纯度高的特点,为规模化生产甘草总黄酮的提取提供了研究基础。     

紫外辐射对东北红豆杉鲜叶中紫杉醇及三尖杉宁碱含量的影响

分别采用254、365 nm两种波长的紫外光对东北红豆杉鲜叶进行辐射,研究了波长、辐射时间以及样品处理方式对东北红豆杉鲜叶中紫杉醇及三尖杉宁碱含量变化的影响。结果表明,东北红豆杉鲜叶经匀浆处理后接受紫外辐射,两种波长的紫外光都可以使紫杉醇及三尖杉宁碱的含量增加,但不同波长对紫杉醇及三尖杉宁碱含量提高的趋势却不相同。365 nm的紫外光辐射2 h时使紫杉醇和三尖杉宁碱含量均提高到了最大值,两种物质含量分别提高了44.6%和53.0%,而254 nm的紫外光在辐射8 h时才达到最大值,两种物质含量分别提高了39.2%和24.3%。可以选取365 nm的紫外光对东北红豆杉鲜叶水匀浆体系进行辐射,快速高效地提高鲜叶内紫杉醇和三尖杉宁碱的含量。     

基于RNA-seq技术对乌头属铁棒锤中自交不亲和S基因的挖掘与分析

以毛茛科乌头属铁棒锤 (Aconitum pendulum N. Busch)2个品系‘蓝花铁棒锤’(‘WSYB1’)和‘黄花铁棒锤’(‘WSYY1’)为材料, 对其进行转录组测序(RNA-seq), 采用生物信息学方法鉴定其中可能存在的花柱S基因(self-incompatibility gene)和花粉S基因, 并...     

鲟源致病性豚鼠气单胞菌的分离及其生长特性

从患细菌性败血综合征的杂交鲟(Husohuso♀×Acipense rruthenus♂)肝和达氏鳇(H.dauricus)腹水中共分离出4株优势菌,经人工回归感染实验测定了其致病性,并通过ATB细菌鉴定仪对致病菌株进行了鉴定,此外,研究了致病菌株的生长特性。实验结果表明,菌株XL2-T对杂交鲟和达氏鳇具有致病性。经鉴定,菌株XL2-T为豚鼠气单胞菌(Aeromonas punctata caviae);其在无菌营养肉汤中摇床振荡培养时的生长曲线:0～1.5h为生长延迟期,1.5～28h为对数生长期,28～32h为稳定期,32h以后为衰亡期;其最适生长温度为25～30℃,最适生长pH为7,在NaCl含量范围0～10%、沙拉沙星浓度范围0～40μg/ml下均能够生长,但NaCl、沙拉沙星对其生长具有较大的抑制作用。