温针灸对膝骨关节炎兔损伤前交叉韧带修复及相关因子的影响

背景:温针灸可有效治疗膝骨关节炎。前交叉韧带的退变、损伤、断裂可影响膝关节局部稳定性,进而诱发膝骨关节炎的形成,温针灸是否可修复损伤前交叉韧带及其作用机制,目前尚不清楚。目的:观察温针灸对膝骨关节炎兔前交叉韧带形态学及相关生长因子类胰岛素样生长因子1、转化生长因子β表达的变化,明确温针灸修复前交叉韧带的作用机制。方法:将30只新西兰兔采用随机数字表法分为空白组、模型组、温针灸组3组,每组10只。模型组和温针灸组兔采用石膏管型固定法制备膝骨关节炎兔模型。造模成功后,模型组每日于兔固定架固定15 min;温针灸组选取“鹤顶”“内膝眼”“外膝眼”行温针灸治疗,每日1次,7日为1个疗程,共治疗2个疗程;空白组不予干预。治疗结束后MRI观察前交叉韧带影像学改变,并进行MRI分级统计;透射电镜、苏木精-伊红染色观察其形态学变化;RT-PCR、Western blot检测组织类胰岛素样生长因子1、转化生长因子βmRNA及蛋白的表达。结果与结论:①MRI检查:与空白组比较,模型组前交叉韧带增粗、水肿、部分撕裂,分级评估差异有统计学意义(P<0.05);与模型组比较,温针灸组韧带增粗略轻,轻度水肿,无撕裂,分级评估差异有统计学意义(P<0.05)。②大体观察:模型组前交叉韧带表面光泽变淡,边侧有絮状被膜覆盖,有明显组织坏死;温针灸组韧带表面光泽,韧带呈正常螺旋走形。③苏木精-伊红染色:模型组前交叉韧带内明显组织坏死,大量新生毛细血管,成纤维细胞及胶原纤维排列松散;温针灸组韧带内有少量组织坏死,偶见新生血管,细胞及胶原纤维排列疏松、欠规则。④透射电镜观察:模型组前交叉韧带纤维排列紊乱,粗细不均,分布不均,成纤维细胞较多且形态不规则;温针灸组纤维基本呈纵向排列,纤维粗细、分布不均,少量椭圆形的纤维细胞存在。⑤RT-PCR和Western blot结果:与空白组比较,模型组类胰岛素样生长因子1、转化生长因子βmRNA及蛋白表达明显降低(均P<0.05);温针灸组上述2项指标表达明显升高(均P<0.05)。⑥结果说明,温针灸可改善前交叉韧带的损伤,可能通过调控类胰岛素样生长因子1、转化生长因子β的表达治疗膝骨关节炎。

肾小球血栓性微血管病样改变的超微病理观察

目的:通过对肾活检标本表现为肾小球血栓性微血管病(thrombotic microangiopathy,TMA)或TMA样改变的电镜观察,分析其超微病理改变特征,为临床准确诊断TMA提供超微病理学依据。方法:回顾性分析了560例超微结构具有TMA样改变的肾活检标本,根据肾小球毛细血管内皮细胞损伤范围和程度,分为病理特征典型的肾小球TMA样改变组和病理特征不典型的肾小球TMA样改变组;根据是否合并其它肾脏疾病,分为单纯肾小球TMA样改变组和其它肾脏疾病伴发TMA样改变组。结果:560例标本电镜下均有不同程度的急性和/或慢性内皮损伤的超微病理改变。病理特征典型的肾小球TMA样改变22例(3.9%),病理特征不典型的肾小球TMA样改变538例(96.1%)。单纯肾小球TMA样改变133例(23.8%),其它肾脏疾病伴发TMA样改变427例(76.2%)。结论:电镜观察可发现肾小球毛细血管内皮细胞轻微的病理变化,对于病变轻微或不典型肾小球TMA样改变及其它肾脏疾病伴发TMA样改变,电镜检查具有独特优势。

元宝枫色素含量、分布及超微结构与叶色的关系

【目的】探究元宝枫叶片颜色属性与不同叶色叶片各组织中色素含量和分布,以及与细胞超微结构的关系,为明确元宝枫叶片呈色的内部机制提供细胞学依据,为揭示红叶植物变色机制提供参考。【方法】分析元宝枫叶片颜色属性,测定各颜色叶片叶绿素、类胡萝卜素和花色素苷含量,观察叶片各组织中色素分布情况,使用透视电镜观察叶肉细胞的叶绿体和其他细胞器的超微结构。【结果】元宝枫不同叶色叶片色素含量、分布和超微结构均存在差异。1)红叶花色素苷含量极显著(P<0.05)高于黄叶和绿叶,叶绿素含量较低。黄叶叶绿素含量最低,类胡萝卜素含量显著(P<0.05)高于红叶,类胡萝卜素与叶绿素含量比值显著高于绿叶和红叶(P<0.05)。绿叶叶绿素和类胡萝卜素含量显著(P<0.05)高于黄叶和红叶,花色素苷含量显著(P<0.05)低于红叶,与黄叶之间无显著差异。相关分析表明,元宝枫叶片色素含量比值均与叶绿素含量呈负相关关系。2)元宝枫叶片上下表皮细胞均无色素分布,花色素苷主要分布于栅栏组织。红叶花色素苷分布明显,绿叶和黄叶花色素苷分布较少。黄叶类胡萝卜素分布明显,在海绵组织也有花色素苷分布。3)嫩绿色叶片叶绿体尚在发育中;绿叶细胞发育成熟,有淀粉粒。叶片变红后,叶绿体中核糖体减少,全红叶片中出现叶绿体解体的残留物;黄叶中叶绿体受损,细胞中有嗜锇颗粒;尖端变褐的叶片细胞中有大量嗜锇颗粒,有些细胞基本为空腔。【结论】元宝枫彩叶未发生结构变异,其颜色变化是因为在叶片变红过程中,叶绿素和类胡萝卜素含量降低尤其叶绿素含量下降迅速,而花色素苷含量上升,其内部花色素苷与叶绿素和类胡萝卜素的比值上升造成的,属于色素型彩叶。叶片花色素苷主要分布于栅栏组织,在变红前就已产生,随其含量上升,最终在叶色上呈现出来。在叶色变化过程中,叶绿体逐渐解体,出现衰老症状,为衰老期型彩叶。黄叶生长势差,叶色从绿转黄,不能呈现红色,衰老速度较红叶更快。

小白菊内酯对杏仁核电点燃大鼠的神经保护作用及机制

目的探讨小白菊内酯对杏仁核电点燃癫痫大鼠行为学影响及其机制。方法将40只雄性SD大鼠随机分为4组,每组10只。对照组不进行电刺激,每天给予Tween80腹腔注射;模型组、小白菊内酯低剂量组、小白菊内酯高剂量组每天给予1次电刺激制备杏仁核电点燃癫痫模型,其中小白菊内酯低、高剂量组于电刺激1 h前分别给予小白菊内酯250μg/kg、500μg/kg腹腔注射,模型组给予Tween80腹腔注射,共干预15 d。观察各组大鼠癫痫发作情况;电刺激结束后24 h行Morris水迷宫实验,记录大鼠逃避潜伏期及穿越平台象限百分比;然后检测脑组织中丙二醛(MDA)和还原型谷胱甘肽(GSH)含量,透射电镜观察海马CA1区超微结构。结果随着造模时间的延长,癫痫造模各组大鼠癫痫发作等级逐渐升高,但小白菊内酯低、高剂量组大鼠癫痫发作级别均明显低于模型组(P均<0.05),且小白菊内酯高剂量组明显低于同期小白菊内酯低剂量组(P均<0.05)。水迷宫实验中,模型组大鼠第1~4天的逃避潜伏期均明显长于对照组(P均<0.05),穿越平台象限百分比明显低于对照组(P<0.05);小白菊内酯低、高剂量组大鼠第1~4天的逃避潜伏期均明显短于模型组(P均<0.05),穿越平台象限百分比均明显高于模型组(P均<0.05);可视平台实验中,各组大鼠逃避潜伏期、游泳速度比较差异均无统计学意义(P均>0.05)。与对照组比较,模型组大鼠脑组织中MDA含量明显升高(P<0.05),GSH含量明显降低(P<0.05);海马突触间隙明显增宽(P<0.05),活性带长度明显缩短(P<0.05),突触后致密物厚度明显降低(P<0.05)。与模型组比较,小白菊内酯低、高剂量组大鼠MDA含量均明显降低(P均<0.05),GSH含量均明显升高(P均<0.05);海马突触间隙均明显缩短(P均<0.05),活性带长度均明显变长(P均<0.05),突触后致密物厚度均明显增加(P均<0.05)。与小白菊内酯低剂量组比较,小白菊内酯高剂量组大鼠脑组织中MDA、GSH含量变化更明显(P均<0.05)。结论小白菊内酯对杏仁核癫痫大鼠有很好的神经保护作用,机制可能与其抗氧化和保护海马超微结构有关。

稀释液添加不同抗氧化剂对冷冻姜曲海猪精子质量的影响

旨在探究稀释液中添加不同抗氧化剂对冷冻姜曲海猪精子的保护作用。采用精子直线运动检测精子活力,异硫氰荧光素标记的花生凝集素(FITC-PNA)染色检测精子顶体完整性,碘化丙啶(PI)染色检测精子质膜完整性,体外受精和培养检测受精卵的卵裂情况,透射电镜观察精子超微结构,评价冷冻保存对精子质量的影响;对姜曲海猪精液分别冷冻保存1周、1个月、3个月、6个月、9个月和12个月,观察冷冻保存时间对精子质量的影响;在稀释液中分别添加抗氧化剂甲磺酸米托醌(MitoQ),2,4-二硝基酚(DNP)和4-羟基-2,2,6,6-四甲基哌啶-1-烃氧基(Tempol),每种抗氧化剂均添加25、50和100μmol/L 3种浓度,以筛选出冷冻保存效果最优的抗氧化剂;对添加50μmol/L MitoQ的解冻精子进行透射电镜观察。结果显示:精子冷冻保存不同时间后,各指标均无显著差异(P>0.05);添加不同浓度的MitoQ、DNP和Tempol均对冷冻保存1周精子的活力、顶体完整率、质膜完整率和体外受精卵裂率有一定的改善作用,但以添加50μmol/L MitoQ效果最好;添加50μmol/L MitoQ对精子质膜、线粒体和微管等结构均具有一定的冷冻保护作用。综上,稀释液中添加50μmol/L MitoQ对于超低温保存姜曲海猪精液具有潜在的保护优势,具有一定的开发价值。

阴囊热应激对山羊血睾屏障结构和功能的影响

旨在探究热应激对山羊血睾屏障(BTB)结构和功能的影响,为山羊热应激防治提供理论依据。本研究选择6只1~1.5岁的健康雄性关中山羊,随机分为2组,每组3只。对照组正常饲喂,试验组采用改良后的阴囊热刺激法建立山羊睾丸热应激模型。利用CASA法检测精液质量变化,光镜与透射电镜观测睾丸结构,生物素示踪法显示BTB通透性改变,蛋白质印记法与免疫组织化学法检测BTB关键蛋白表达定位。热应激组中山羊睾丸指数、精子数量、精子活率、精子总运动性和精子前进运动率均显著降低(P<0.05)。热应激导致睾丸组织形态受损明显,生精细胞数量减少且排列紊乱;支持细胞内质网扩张,并出现大量空泡;支持细胞间紧密连接结构松散且不连续。热应激引起BTB通透性升高,关键连接蛋白表达水平显著降低(P<0.05),但分布定位未受影响。热应激损伤山羊睾丸组织形态,破坏支持细胞结构并降低BTB关键蛋白表达,从而导致BTB结构和功能完整性受损,造成精子质量下降,影响雄性山羊繁殖性能。

基于透射电镜下超微结构探讨不同温度悬起灸干预对压疮创面修复的影响

目的 观察不同温度悬起灸干预对大鼠压疮创面组织超微结构的影响,明确悬起灸促进压疮创面修复的最佳干预温度,以期为临床艾灸治疗压疮及慢性难愈性创面提供理论依据。方法 取133只雌性健康SD成年大鼠,随机选择3只大鼠作为空白对照组,其余130只大鼠通过缺血再灌注损伤方式建立2~3期压疮模型。将模型制备成功的125只大鼠随机分为模型对照组、水凝胶组、低温艾灸干预组、中温艾灸干预组及高温艾灸干预组,每组25只。模型对照组和空白对照组仅进行碘伏常规处理;水凝胶组用碘伏处理压疮创面后将水凝胶伤口敷料覆盖于创面处;低、中、高温艾灸干预组给予碘伏处理后分别对压疮创面中心施以38~41℃、43~46℃、48~51℃的悬起灸干预(通过红外热像仪检测创面皮肤表面温度),艾灸干预1次/d,每次持续15 min。分别于干预1,3,5,7,10 d后取各造模组大鼠压疮创面组织,透射电镜下观察压疮组织超微结构;空白对照组大鼠一并取材以观察正常皮肤组织镜下超微结构。结果 与空白对照组相比,各造模组大鼠造模后干预前均出现表皮脱落或损伤及真皮层损伤。(1)表皮修复情况:模型对照组压疮创面中基底细胞结构及功能恢复相对较慢,干预10 d后才可见大部分基底细胞基本恢复正常,但细胞器相对较少,功能较低下。低、中温艾灸干预组干预5 d后可见大部分基底细胞基本恢复正常,中温艾灸干预组可见绝大部分基底细胞基本恢复正常,绝大部分基底细胞的线粒体状态较好,结构较清晰,10 d后基底细胞线粒体数目增多,胶原纤维致密,新生表皮完整,更优于低温艾灸干预组。水凝胶组干预5 d后可见部分基底细胞线粒体肿胀;7 d后可见大部分基底细胞细胞器增多,线粒体结构逐渐恢复正常。高温艾灸干预组干预7 d后可见少部分有线粒体自噬产生,相对略差于水凝胶组。(2)真皮修复情况:模型对照组干预5 d后可见真皮层炎性细胞高度浸润,成纤维细胞变性;7 d后真皮层尚有少量炎性细胞,真皮成纤维细胞增生并有功能恢复,少部分胶原纤维相对较致密;10 d后真皮成纤维细胞增生明显,真皮有淋巴细胞,真皮损伤有恢复,部分胶原纤维相对较致密。中温艾灸干预组干预1 d后真皮层出现大量的炎性细胞浸润;5 d后可见真皮层不新鲜的粒细胞浸润,大量的成纤维细胞增生活跃,大部分胶原纤维较致密;7 d后绝大部分真皮成纤维细胞数目增多,功能活跃,且胶原纤维较致密;10 d后真皮成纤维细胞功能旺盛,胶原纤维致密。低温艾灸干预组可见上述类似大体趋势;水凝胶组及高温艾灸干预组干预5,7,10 d后亦可见真皮成纤维细胞不同程度的增生,其功能亦逐渐恢复,胶原纤维排列逐渐致密,但修复情况均较中温艾灸干预组差。结论 不同温度悬起灸干预及水凝胶处理能够整体上提前压疮创面急性炎症浸润的高峰,促进压疮创面由炎症损伤阶段向增殖修复阶段的顺利转变,继而加快压疮创面修复进程。不同温度悬起灸干预后压疮创面修复存在一定差异,其中38~41℃、43~46℃温度下悬起灸更有利于促进压疮组织残存表皮修复、新生表皮生成及真皮浅层修复,且43~46℃温度下悬起灸更具优势。

Ultrastructure Features of Sperm Cell in Amaryllis vittata

Ultrastructure of sperm cells in pollen tube of Amaryllis vittata Ait. has been investigated in details by electron microscopy ,with particular emphasis on the organization and distribution of microtubules.The two newly formed sperm cells are arranged in tandem and sometimes in transverse at the right angle to the long axis of the pollen tube.Thevegetative nucleus is ahead and closely associated with the two sperm cells in all examined pollen tubes. The microtubules are distributed in the region between the common cell wall and the proximity of the sperm nucleus,they are singles and dispersed with mainly orientation of longitudinal and oblique,forming a loose bucket-like structure as a whole.In late stage of development,all of the microtubule array longitudinally and enclose the sperm nucleus.This configuration is very similar to the basket-like structure of microtubule in the generative cell. These results show that the organization and distribution of microtubules in the sperm cells are dynamic during cell development.

施氮量对云烟121上部烟叶代谢及品质的影响

为提高烤烟上部叶品质与可用性,筛选出曲靖烟区云烟121适宜的施氮量,分别施用纯氮82.5、105.0和127.5 kg·hm^(-2)进行大田试验,测定不同处理的农艺性状、上部成熟鲜烟叶的超微结构及烘烤后的外观质量、化学成分、感官质量等指标,并进行代谢组学分析,综合评价不同施氮量处理下云烟121的生长情况与上部烟叶品质。结果表明,3个施氮量处理烟株的长势无明显差异,其中105.0 kg·hm^(-2)处理烟株的综合发病率最低。随着施氮量的增加,云烟121上部叶片中的叶绿体降解减缓,淀粉粒与嗜锇颗粒体积增大,其中105.0 kg·hm^(-2)处理烟叶的嗜锇颗粒数量最多。施氮水平影响云烟121上部叶的代谢模式,且主要集中在莽草酸和苯丙烷代谢途径。在105.0 kg·hm^(-2)处理下,云烟121上部叶烤后的外观质量、化学成分、感官质量、经济性状均优于其他施氮水平。由此表明,施用纯氮105.0 kg·hm^(-2)能够有效提高曲靖烟区云烟121上部叶的品质与可用性。

大辟缘蝽触角感器的扫描电镜观察

为了解大辟缘蝽(Prionolomia gigas Distant)触角感器与其嗅觉感受机制的关系,采用扫描电镜观察大辟缘蝽雌、雄成虫触角感器类型、超微形态及其分布。结果表明:大辟缘蝽雌、雄成虫触角均呈线状,由柄节、梗节和鞭节3部分组成;雌、雄成虫触角上共观察到6种类型感器,分别为毛形感器、刺形感器、锥形感器、腔形感器、腔锥形感器和具弯钩型感器,其中,以毛型感器数量最多、分布范围最广,鞭节上的感器类型较柄节和梗节丰富,雌虫的感器类型多于雄虫,表现出明显的性二型现象。

断尾对兰州大尾羊脂肪细胞结构和脂肪代谢相关基因表达的影响

旨在观察断尾对兰州大尾羊尾部脂肪细胞数量、结构以及皮下脂肪、大网膜脂肪、尾部脂肪、肾周脂肪和背最长肌脂肪代谢相关基因表达的影响,明确断尾引起脂肪沉积重新分布后,脂肪细胞和各脂肪沉积部位脂肪代谢相关基因表达的变化,为阐明断尾对脂尾型绵羊脂肪代谢调控的分子机理提供参考。选择5日龄[(3.79±0.12)kg]单羔兰州大尾羊羔羊18只,随机分为对照组(C组)和试验组(T组),每组9只羔羊,试验组羔羊采用橡皮圈结扎法断尾。试验羊2月龄断奶后饲喂配合日粮,两组羊日粮相同。试验期240 d。试验结束后,采集样品进行分析。1)相对于背最长肌肌内脂肪和内脏脂肪,断尾对尾部脂肪、皮下脂肪基因表达影响较大,断尾组尾部脂肪SCD、LEP、PLIN1的mRNA表达量显著升高,LPL、FAS、PEPCK的表达量显著降低(P<0.05);皮下脂肪中SCD显著升高,LEP、ADPN、FABP4、PLIN1显著降低(P<0.05);肾周脂肪中LPL、ADPN、PEPCK、UCP1和大网膜脂肪中的PEPCK显著降低(P<0.05);背最长肌中SCD显著升高,PEPCK、PLIN1显著降低(P<0.05)。2)断尾组背最长肌的肌内脂肪含量(6.96%和6.05%)、脂滴面积比(4.28%和3.04%)显著增加(P<0.05),脂滴面积比增加了约1%,而尾部脂肪中脂滴面积比例降低了约10%(87.43%和97.58%),尾部脂肪细胞直径显著降低(P<0.05);3)兰州大尾羊尾部脂肪细胞被融合的大脂滴填充,细胞核、细胞质等被大脂滴挤到细胞边缘,细胞边缘的细胞质薄层中含有线粒体、内质网、高尔基体、自噬小体等细胞器和小脂滴,断尾组尾部脂肪细胞质中单个脂滴体积较小,周围糖原颗粒较多。综上所述,长脂尾型绵羊兰州大尾羊早期断尾后,背最长肌的脂滴面积比增加,尾部脂肪中脂滴面积比降低,尾部脂肪细胞直径减小,各部位脂肪代谢相关基因表达也发生变化,断尾后脂肪沉积分布改变可能是在SCD、PLIN1、LPL、FAS、PEPCK等一系列脂肪代谢相关基因的调控下实现的。

Physiology and Ultrastructure of Azolla imbricata as Affected by Hg 2+ and Cd 2+ Toxicity

The toxic effects of different gradient concentrations of Hg2+ and Cd2+ on chlorophyll content, chlorophyll a/b value, photosynthetic O-2 evolution, respiration rate, anti-oxidase system (superoxide dismulase (SOD), catalase (CAT), peroxidase (POD)) and ultrastructure of the cells of Azolla imbricata (Roxb.) Nakai were studied. The results showed that with Hg2+ and Cd2+ increase, chlorophyll content and chlorophyll a/b value, photosynthetic O-2 evolution decreased drastically; respiration rate peaked at 2 mg/L pollutant and declined afterwards. The activities of SOD, CAT and POD increased first and decreased afterwards except the activity of POD, which decreased with the increasing of Cd2+ concentration. Ultrastructural observation showed that the extent of ultrastructural damage was much more serious with higher pollutant concentration and longer time of stress. This resulted in swelling of chloroplast, disruption and disappearance of chloroplast membrane and disintegration of chloroplasts; swelling of cristae of mitochondria, deformation and vacuolization of mitochondria; condensation of chromatin in nucleus, dispersion of nucleolus and disruption of nuclear membrane. The experimental results showed: (1) Hg2+ and Cd2+ pollution not only destroyed physiological activities, but also caused irreversible damage to its ultrastructure, thus leading the cells to death; (2) With increase in the stress of Hg2+ and Cd2+, ultrastructural damage was related to the changes of plant physiology; (3) The toxic symptoms of plant showed an evident correlation between dose and effect; (4) The toxicity of Cd2+ on A. imbricata is heavier than that of Hg2+ under the same treatment time and concentration. The lethal concentration of Hg2+ to A. imbricata ranged from 3.5 to 4 mg/L, and that of Cd2+ ranged from 3 to 3.5 mg/L. The damage of cell ultrastructure on Anabaena azollae Strasburger was observed. The results indicated that tolerance of Azolla imbricata for Hg2+ and Cd2+ was higher than that of A. imbricata.

基于胃微观动力结构研究整肠散干预兔功能性胃排空障碍的药效作用机制

目的探讨整肠散穴位贴敷干预功能性胃排空障碍(FDGE)的可能药效作用机制。方法将30只雄性家兔按随机数表法分为正常组、模型组和穴位贴敷组,每组各10只。正常组行假手术,模型组和穴位贴敷组家兔行胃大部分切除术进行造模。正常组与模型组给予无药穴位贴敷,穴位贴敷组行整肠散穴位贴敷,各组均干预14 d。检测术日术前及术后第15日家兔血钾(K+)、胃动素(MTL)水平;术后第16日通过测定胃内色素残留量反映残胃排空功能;术后第16日运用电镜行残胃平滑肌细胞及Cajal间质细胞(ICC)的超微结构测定。结果与正常组比较,模型组MTL、K+的含量显著降低(P<0.001),与模型组比较,穴位贴敷组MTL、K+的含量显著提高(P<0.001);与正常组比较,模型组胃内色素残留量升高(P<0.001);与模型组比较,穴位贴敷组胃内色素残留量显著降低(P<0.001)。与正常组比较,模型组细胞核排列紊乱,形态不规则,ICC细胞结构模糊,核固缩,线粒体少,出现空泡。而与模型组比较,穴位贴敷组细胞破损较轻,排列较整齐,ICC细胞结构较清晰,突起增多,未见自噬小体,提示整肠散穴位贴敷能够改善兔胃黏膜细胞损伤,改善胃大部分切除术后家兔平滑肌细胞中ICC的超微结构。结论整肠散穴位贴敷能够有效预防家兔胃大部分切除术后FDGE的发生,其作用机制可能与稳定K+水平,促进MTL分泌,提高胃排空功能,改善残胃平滑肌细胞与ICC的超微结构有关。

Development and Ultrastructure of the Phloem Ganglion in Bamboo Node

The development, cytological characters and ultrastructure of phloem ganglion in the nodal region of Phyllostachys edulis (Carr.) H. de Lehaie, a most economically important bamboo, were investigated and the possible physiological function of this special structure was proposed. The phloem ganglion derived directly from procambium is situated at the sites where the vascular bundle forks and is present in pairs. The phloem ganglion is spindle_like in appearance and usually consists of 4 to 6 layers. Two kinds of cells in the ganglion could be distinguished. In the middle, there are two layers of filiform cells with pointed ends so that there are no normal sieve plates. Nevertheless, there are many pits on the lateral wall of the filiform cells. The other type of cells located at both ends of the spindle which possess an intermediate form between the filiform cell and the normal sieve tube. The walls of these cells towards the filiform cells are strongly convex forming a special sieve plate. Ultrastructure study showed that cells in the ganglion are connected by enriched plasmodesma. During early differentiation, the paramural body and the ingrowth of cell wall could be observed. It indicates that the cells of phloem ganglion have the character of transfer cells. The organelles in the mature cells are mainly plastids with abundant accumulation of proteins of crystalline structure. The above_mentioned results suggest that the physiological function of the phloem ganglion is closely related with substance transport.

Ultrastructure of Epidermis and Flesh of the Developing Apple Fruit

The ultrastructure of the epidermis and flesh of apple ( Malus domestica Borkh cv. Red Fuji) fruit was systematically observed during the fruit development via transmission electron microscopy. The results showed that, in spite of the ultrastructural changes in many aspects of the developing fruit epidermal cells, it remained almost unchanged throughout the whole developmental process that the cytoplasm was filled with numerous endoplasmic reticula (ER). Most of these endoplasmic reticula were tube_like and rough_ER with enlarged cisterna from which many vesicles were produced. Some of the vesicles were shown to merge into vacuole. Some dynamic Golgi bodies were also found. All the ultrastructural characteristics showed that the epidermal cells have the features of excretory cells. The ultrastructure of the fruit flesh cells at the young fruit stage were shown to be metabolically active, characterized by the presence of numerous clustered plasmodesmata, cisterna enlarged_ and rough_ER filling the cytoplasm, plenty of vesicles and Golgi bodies, indicating their dynamic cellular transport function. Some giant_circular rough_ERs were found. All the ultrastructural features at this early developmental stage should be closely associated with the enlargement of the young fruit. At the rapid growing phase of the fruit the main changes were characterized by: the starch grain_filled amyloplasts, furcating of the single orifice of plasmodesmata, and the cytoplasm enrichment of both the Golgi body_formed vesicles and other vesicles. These features correspond well with those of a photoassimilate sink_cell. An ultrastructural degeneration phenomenon was observed at the fruit ripening stage, but the mitochondria and plasmalemma still remained intact, which might be related to the continuous development of fruit quality during the fruit ripening.

Ultrastructure of the Multicellular Nodules in Hypericum perforatum Leaves

With the development of the multicellular nodules in the leaves of Hypericum per plastids increased both in number and volume, and some plastids degenerated and were surrounded by dark tubular elements and vesicles. Some vesicles fused with vacuoles and secreted substances into vacuoles. There are many multivesicles, multimembrane structures and osmiophilic droplets in vacuoles of nodule cells. Meanwhile, dictyosome secreted vesicles into the vacuoles. However, there is a large central vacuole completely filled with secretory materials (hypericin) in matured multicellular nodules. This suggests that the osmiophilic droplets may be a precursor of hypericin originated from the degenerated plastids. There were abundant endoplasmic reticulums and dictyosomes between the plastids and osmiophilic droplets, suggesting that they may be involved in the synthesis and/or transport of the precursor of hypericin.

Ultrastructure of Oogenesis in Osmunda cinnamomea var. asiatica

The ultrastructure of oogenesis in the fern Osmunda cinnamomea L. var. asiatica Fernald has been studied by electron microscopy. During oogenesis, numerous vesicles not only moved towards the periphery, but also were arranged in line along the inside of plasmalemma, and in addition aggregated outside the plasmalemma by exocytosis. They released or excreted osmiophilic material. It was observed that a few vesicles containing lamellar osmiophilic material situated closely along the plasmalemma, seemed to break open. Simultaneously, a separation cavity between egg cell and archegonium wall formed. Its width was broader than the other advanced ferns reported previously, and an extra egg membrane occurred outside around the plasmalemma of the egg, its thickness being greater than in Pteridium and Dryopteris. Amyloplasts around the nucleus were filled with large triangular semicircular or subelliptical starch grains, but as the egg matured they progressively decreased. Nucleus was large and flattened, and paired membrane in two to three couples laid within the nucleus, close and parallel to the nuclear membrane. No nuclear evagination was observed. Mitochondria seemed to have been undeveloped, but finally recovered normally.

Ultrastructure of the Blepharoplast and the Multilayered Structure in Spermatogenesis in Osmunda cinnamomea var. asiatica

The ultrastructure of the blepharoplast and the multilayered structure (MLS) in the fern Osmunda cinnamomea var. asiatica Fernald have been studied by electron microscopy with respect to spermatogenesis. The blepharoplast appears in the young spermatid. The differentiating blepharoplast is approximately a spherical body, which is composed of densely stained granular material in the center and some cylinders outside of it. The differentiated blepharoplast is also a sphere, but without the densely stained material in the center, consisting of scattered or radially arranged cylinders. The MLS seen in the spermatid lies between the basal bodies and the giant mitochondrion. In the early developmental stage, the MLS only consists of lamellar layers, each of which runs parallel to one another and forms a strip. In the mid stage, the MLS is composed of the microtubular ribbon (MTr), the lamellar layers and a layer of plaque. In the late stage, the MLS forms accessory band, osmiophilic crest and a layer of osmiophilic material. The MTr grows out from the MLS and extends along the surface of the nucleus to unite with the nuclear envelope in a complex. The basal body coming from the cylinder produces the axoneme of the flagella in the distal end and the wedge-shaped structure in the proximal end, respectively. In the present study, the ultrastructural features of blepharoplast and the MLS of the protoleptosporangiopsida fern, O. cinnamomea var. asiatica, have been described and compared with those of other kinds of pteridophytes in detail. The lamellar layers appearing before the formation of the MTr was found and reported for the first time.

ULTRASTRUCTURE OF THE VEGETATIVE CELLS OF NOSTOC FLAGELLIFORME PREPARED WITH HIGH PRESSURE FREEZING AND FREEZE SUBSTITUTION TECHNIQUE

The ultrastructure of the vegetative cells of Nostoc flagelliforme Born. et Flah. was investigated with high pressure freezing and freeze substitution technique and compared with the results obtained by using conventional preparation methods. During the processes of chemical fixation, dehydration and embedding, the cell structures might be more artificially modified than that obtained from high pressure freezing and freeze substitution. With the present method, the sheath of N. flagelliforme could be well penetrated and no extra big space could exist between the cell and the sheath. The cell protoplasm rarely shrinked. Some fine structures of cell inclusions and unit membranes became visualized. Many bacteria were harbored in the sheath. In addition, the presence of big vacuoles in the cell of N. flagelliforme as well as the presence of bacteria in the sheath shown in the present preparation for cyanobacteria has not been described so far in the literature.

Effects of CO_2 Enrichment on Microstructure and Ultrastructure of Two Species of Freshwater Green Algae

order to investigate the morphological response of freshwater green algae to elevated CO2 concentration, Chlamydomonas reinhardtii Dang and Scenedesmus obliquus Kutz were cultured with enriched CO2, and their microstructure and ultrastructure were examined by microscopy and electron microscopy. The effect of CO2 enrichment to 186 mumol/L, was insignificant on the shape and size of C. reinhardtii, but significant in reducing the volume of S. obliquus. High-CO2 increased the amount of chloroplast. The pyrenoids occurred in low-CO2-grown cells but not in high-CO2-grown ones and more starch granules were observed in the former.