低温胁迫对日本对虾抗氧化系统和细胞凋亡的影响

日本对虾(Marsupenaeus japonicus)适宜生长温度为23℃～32℃,由于北方地区冬季温度较低,严重影响日本对虾养殖周期,因此,培育耐低温的新品种非常重要.将(14.24±1.12)g的日本对虾暴露于10℃、16℃、22℃水体中72h,以28℃水体中的对虾为对照组.结果显示,对虾鳃和肝胰腺的总抗氧化能力...     

Morphological and histochemical investigation of the response of Olea europaea leaves to fungal attack by Spilocaea oleagina

This study investigated the response of Olea europaea (cv. Conservolea) leaves to attack by the fungal pathogen Spilocaea oleagina. Cryostat and semithin sections of healthy and S. oleagina‐infected olive leaves were analysed histochemically for polyphenol oxidase (PPO) activity and tested for programmed cell death (PCD) induction by means of terminal deoxynucleotidyl transferase‐mediated dUTP nick end labelling (TUNEL). At all stages of infection, the fungus remained localized between the external and internal layers of cuticle without crossing the pectocellulosic layer. No PCD phenomena could be detected in plant cells at any stage of the disease. However, extensive degeneration of palisade parenchyma cells was observed in advanced infections, with massive loss of cytoplasmic contents and disappearance of cell compartments. Polyphenol oxidases are enzymes that, in olive, oxidize o‐diphenols (principally oleuropein and rutin) to produce o‐diquinones and melanins, substances that are toxic to many pathogens. No significant increase in overall PPO activity was found in infected leaves; on the contrary, enzyme activity was gradually lost as infection progressed, most probably due to degradation of plastids within mesophyll cells, in which such enzymes are normally confined. Only a limited local PPO activation occurred in a few upper epidermal cells of the leaf, indicating a feeble induction of a plant response.     

TUNEL法检测PRRSV感染Marc-145细胞凋亡的研究

为了研究PRRSV诱导Marc-145细胞凋亡的动态变化规律，收集PRRSV-SC1株感染Marc-145细胞后0h、24h、48h、72h、96h、120h、144h和相同时间点未接种病毒的细胞样品，采用TUNEL法进行细胞凋亡的检测。结果表明，PRRSV能诱导Marc-145细胞发生凋亡；在PRRSV感染后24h开始出现凋亡，48h凋亡更加明显，72h达到高峰，随后细胞凋亡水平又有所下降，在感染后144h，细胞的凋亡水平低于正常组。     

低氧胁迫对鲢肝和脑细胞凋亡的影响

【目的】通过磷脂结合蛋白V/碘化丙啶(Annexin V/PI)流式细胞分析法和原位末端脱氧核苷酸转移酶标记(TUNEL)法检测低氧胁迫下鲢肝、脑细胞的凋亡情况。【方法】将鲢分成对照组和低氧处理组,对照组正常饲养,低氧处理组用保鲜膜将水箱上口封住进行低氧处理,分别在鲢浮头期以及死亡期取其肝、脑组织,同时取对照组鲢肝、脑组织,采用Annexin V/PI流式细胞分析法和TUNEL法检测其细胞凋亡情况。【结果】Annexin V/PI流式细胞仪分析结果表明,在鲢肝脏中细胞凋亡率依次是对照组8.85%、低氧处理组浮头期22.06%、低氧处理组死亡期22.91%;脑中细胞凋亡率依次是对照组8.18%、低氧处理组浮头期24.80%、低氧处理组死亡期24.86%。TUNEL法检测结果显示,肝脏中细胞凋亡率是对照组3.80%、低氧处理组浮头期36.78%、低氧处理组死亡期37.27%;脑中细胞凋亡率依次是对照组6.74%、低氧处理组浮头期35.04%、低氧处理组死亡期35.71%。与正常对照组比较,低氧胁迫后鲢肝、脑细胞凋亡率极显著增大,但随着低氧胁迫时间延长细胞凋亡率无明显差异。【结论】低氧胁迫会极显著促进鲢肝和脑细胞发生凋亡,但鲢肝、脑组织中细胞凋亡率不会随着低氧胁迫时间延长而产生显著差异。     

Can Nutraceuticals Affect the Structure of Intestinal Mucosa? Qualitative and Quantitative Microanatomy in L -Glutamine Diet-Supplemented Weaning Piglets

Weaning piglets were fed an L -glutamine-supplemented diet with the aim of monitoring the effects on gut mucosal turnover and barrier function, to elucidate the potential preventive or therapeutic roles of glutamine as a nutraceutical or ‘functional food’. Sixteen female weaning piglets were divided into two groups, which were fed a control diet (Ctr group: n = 8) or a Ctr + 0.5% L -glutamine diet (G group: n = 8) for 28 days. In the ileum of group G piglets the villus height (V) and crypt depth (C) were increased, and the V:C ratio was decreased (p < 0.01). The PCNA and TUNEL immunoreactivities were also tested. The number of mitotic mucosal cells (M) was increased, and that of mucosal cells with apoptotic nuclei (A) decreased in such a way that the A:M index diminished (p < 0.01). The A:M index also decreased at the level of some components of the gut-associated lymphatic tissue (GALT), thus indicating a positive effect on the gut barrier function. This trial showed that L -glutamine supplementation influenced some morphofunctional characteristics of piglet ileal mucosa. These data corroborate the nutraceutical role of glutamine as a trophic agent for mucosal repair, improvement of barrier function and gut adaptation in the swine per se and as an animal model.     

大鼠短暂性全脑缺血再灌注后海马神经元动态变化

采用股动脉放血并双侧颈总动脉夹闭制作大鼠全脑缺血再灌注模型,分别于术后6h、1d、3d、5d处死动物,取脑,制作石蜡切片和冰冻切片,通过HE染色、TUNEL检测及Caspase-3活性测定,对大鼠海马各区锥体细胞形态进行动态观察。结果表明:在短暂性全脑缺血中,海马锥体细胞存在着凋亡和坏死两种死亡形式,细胞凋亡在海马各区中的分布是一动态过程,各区对缺血易损伤性的顺序是:CA1及门区>CA2>CA3>齿状回;脑缺血再灌注不同时间,海马锥体细胞中DNA断裂及Caspase-3的表达与细胞凋亡呈现相似的变化趋势,且DNA的断裂早于Caspase-3的表达;与青年组相比,老年组海马神经元出现凋亡时间早且损伤严重。试验证明:在脑缺血再灌注损伤中,海马各区存在着缺血耐受性差异;细胞凋亡是神经元死亡的一种重要形式。     

醋酸铅对小鼠卵巢组织结构和卵巢颗粒细胞凋亡的影响

将40只20日龄雌性昆明系小鼠随机分成3个处理组和1个对照组,每组10只。给3个处理组小鼠分别连续2d腹腔按体质量注射醋酸铅10,20,40mg/kg,对照组小鼠注射等体积的生理盐水。于注射后24,72h分离卵巢,用原位末端标记法(TUNEL)测定卵巢颗粒细胞的凋亡率,研究卵巢组织结构及卵巢颗粒细胞凋亡的变化。结果显示,醋酸铅可使小鼠卵巢组织结构发生病变,加速卵巢颗粒细胞的凋亡,且凋亡率随着攻毒剂量的增加和时间的延长而升高,与对照组相比,差异极显著(P0.01);表明醋酸铅对小鼠卵巢具有毒性作用,可诱导卵巢颗粒细胞发生凋亡,并呈现一定的剂量-时间依赖关系。     

脱氧雪腐镰刀菌烯醇诱导血管内皮细胞凋亡及其凋亡相关因子的初步研究

脱氧雪腐镰刀菌烯醇（DON）是由镰刀菌属病原真菌产生的真菌毒素之一,在自然界广泛存在,可引起人畜中毒。为了解DON对血管内皮细胞的危害及其可能机制,本试验采用不同浓度的DON（0.25-10μg/mL）作用于猪髋动脉内皮细胞（PIEC）和人脐静脉内皮细胞（HUVEC）2种细胞24 h,倒置显微镜下观察其形态变化,MTT法测定细胞增殖的变化,TUNEL法检测细胞凋亡率,免疫组织化学染色方法测定细胞凋亡过程中Caspase-9和Bax表达的变化。结果显示,高浓度DON可明显改变细胞的形态;不同浓度的DON均可抑制细胞的增殖;TUNEL凋亡检测结果显示,不同浓度的DON对这2种细胞均有诱导凋亡的作用;对于PIEC细胞,在DON浓度为0.5μg/mL时,凋亡率达到最高（71.74%）;HUVEC细胞则在DON浓度为5μg/mL时,凋亡率达到最高（26.61%）,此后随浓度的升高,凋亡率下降,可能与凋亡细胞崩解脱离细胞片有关。根据试验结果初步推断,DON诱导PIEC凋亡可能与Caspases途径有关,Bax在其中起到了一定的凋亡促进作用;而在诱导HUVEC细胞凋亡的过程中未检测到Caspase-9和Bax的变化,故认为DON诱导HUVEC细胞凋亡与Caspases途径和促凋亡因子Bax均无关。