鸡INR的神经束与血－神经屏障的超微结构

 【目的】研究鸡肠Remak神经（INR）神经束的超微构造与血－神经屏障的微细形态,为进一步阐明INR的生理功能提供理论基础。【方法】应用透射电镜技术研究鸡肠Remak神经（INR）神经束的超微构造与血－神经屏障的微细形态。【结果】鸡INR被神经束膜分隔成许多神经束,束内既有无髓纤维又有有髓纤维,但以无髓神经纤维的数量占绝对优势。雪旺氏细胞与两种神经纤维的形成与结构密切相关。神经束膜细胞突起长而薄,包绕神经束,其丰富的粗面内质网、线粒体和发达高尔基复合体,以及以常染色质为主的细胞核和明显的核仁结构,提示束膜细胞具有活跃的蛋白合成和分泌功能。不同于肠壁内ENS缺乏神经屏障的现象,鸡INR的神经束膜中分布有血－神经屏障,是由结构紧密的毛细血管及其周围多层排列的束膜细胞形成的,且束膜细胞表面可见吞饮泡的形成,但未见不同束膜细胞之间有特殊的细胞连接。这种组成特点表明,鸡INR的血－神经屏障没有哺乳动物外周神经的严密。【结论】上述试验结果显示,鸡INR的细胞学结构既不同于肠壁内ENS,也与外周神经有差异,具有一定的特殊性。     

Characterizing the cytoplasmic diversity and phyletic relationship of Chinese landraces of soybean, Glycine max, based on RFLPs of chloroplast and mitochondrial DNA

Restriction fragment-length polymorphism (RFLP) of chloroplast and mitochondrial DNA of many soybean landraces were analyzed to characterize their cytoplasmic genome and to consider the diversity and phylogeny of soybean in China. Three chloroplast and five mitochondrial types were distinguished, and seven cytoplasmic genome types were observed in different combinations in specimens collected from China. The cytoplasmic genome diversity was higher at the Yangtze River Valley. The main group of cytoplasmic genomes was composed of five types related phylogenetically and occurred in the southern region of China. Two unique types were very different in cytoplasmic genome constitution from each other and from the main group. They were considered to be derived from wild plants with the same cytoplasmic genome and to occur in two remote regions, the northern region and the Yangtze River Valley of China, respectively. Therefore, when considered with regard to the cytoplasmic genome of soybean landraces detected in China, seven genome types are distinguished, some types may be assumed to have arisen in wild soybean before domestication; and the Yangtze River Valley is the center of cytoplasmic diversity of the soybean.     

马杜霉素对柔嫩艾美耳球虫(Eimeria tenella)超微结构的影响

将马杜霉素按 0 .0 0 0 5 %的比例混入饲料 ,作用于鸡体内柔嫩艾美耳球虫 (Eimeria tenella) ,透射电镜观察 ,发现裂殖体变小 ,内含裂殖子的数目减少 ,裂殖子膨胀变为椭圆 ,裂殖子间 (带虫空泡内 )微管结构模糊、膨胀 ,裂殖体中有髓鞘样结构出现 ;细胞膜外突和细胞质分离形成空隙 ,细胞膜有破损、结构模糊 ;细胞质出现空泡化 ,内部出现附加体和髓鞘样结构 ;少数细胞核的外膜外突和内膜分离 ,有的部位的核膜模糊、破损。裂殖子顶体结构发生异常变化 ,棒状体消失 ,微线数目减少或者消失。线粒体表现为形态改变 ,肿大变圆 ,或者变为马蹄形 ,内膜和嵴脱落 ,内部形成空泡、膜状结构、螺旋状或者髓样结构 ,线粒体的嵴与长轴平行排列 ,且贯穿线粒体。作者推测 ,抗生素类抗球虫药的作用机理可能是 ,通过使虫体结构的完整性受损 ,抑制虫体的物质代谢及能量代谢等生理机能 ,达到杀死虫体或者抑制虫体生长、发育和繁殖的目的。     

Studies on Globidial Schizonts in the Abomasum of Norwegian Sheep: The Fine Structure of One of the Four Merozoite forms Investigated

Norwegian sheep were investigated for globidial schizont infection in the abomasum. The frequency of infection was found to be 78.2 %. Light microscope studies of the various mature schizonts revealed the existence of four morphologically different merozoites, small A, small B, intermediate and long forms. Each globidial schizont was found to contain only one form of these merozoites. However, these four schizont types occurred in the same abomasum.The intermediate form of globidial schizont merozoites was investigated by the aid of an electron microscope, with the aim of comparing its internal morphology with that previously published for Eimeria species. A striking resemblance was observed between the fine structures of the intermediate merozoite and that of Eimeria species, particularly the first generation merozoites described in giant schizonts of Eimeria bovis.The present status of globidial schizonts infecting the abomasum of sheep was discussed. It was concluded that these four forms of merozoites could represent different generations of one Eimeria species or different E. species producing giant schizonts in the abomasum.Due to the practical difficulties in studying the life histories of the different Eimeria species infecting sheep, it was proposed that the in vitro propagation of the individual species in cultured cells may shed some light on the corresponding asexual, as well as the sexual, stages. This would offer a new approach to the study of the ultra-structure of the developing parasite.     

滇—型粳稻雄性不育系花粉发育的研究

 滇一型粳稻雄性不育系花粉母细胞的减数分裂和花药绒毡层的发育是正常的。在花粉发育的单核期,小孢子的超微结构,二丙酸酯荧光素分解酶活性变化,酯酶同工酶以及离体培养再生植株的能力与保持系并没有明显的差异,但是,花粉发育到雄配子体时期,发育速度显著减慢,生殖细胞分裂迟缓,因此,花粉没有受精能力,花粉发育速度在品种间存在着差异。但超微结构和酶的活性研究表明,大多数花粉并未发生不可逆转的败育,较高的温度有加速发育的效应,可以使部分花粉具有受精能力。     

兔脑炎原虫的超微形态与发育

用电镜连续７代动态地观察了培养细胞中兔脑炎原虫的超微结构与发育状态。脑炎原虫含有细胞核，但无线粒体、内质网和高尔基复合体等细胞器，其表面有几根极丝。脑炎原虫在培养细胞中除二分裂增殖外，还有裂体增殖和配体增殖。由于脑炎原虫有３种增殖方式，故在光学显微镜下呈多形态结构。     

肉鸡腹水症心肝肺显微和超微结构研究

运用光镜、电镜技术，观察了肉鸡腹水症自然发病鸡心、肝、肺的显微和超微结构。肺呈弥散性充血和水肿，三级支气管和肺房扩张，平滑肌肥大，软骨样和骨样小结节病灶明显增多，呼吸毛细管上皮细胞内出现大量空泡，肺气－血屏障结构受破坏。心脏肥大，右心扩张，心肌纤维间淤血、水肿，充满大量炎性细胞和结缔组织细胞。心肌变性坏死，肌原纤维断裂，有的横纹消失。肝充血肿大，表面被覆一层灰白色或淡黄色胶冻样物。肝血窦扩张，肝细胞索排列紊乱，肝细胞界限不明显，肝细胞质内的线粒体嵴模糊不清     

肉鸡腹水症发病机理的研究Ⅲ.低温对肉鸡心功能和心室结构的影响

本研究采用心电图描记技术动态检测低温环境下肉鸡右心功能的变化，同时利用电镜技术观察心肌超微结构的病理变化。研究表明低温处理1周后心电图Ⅱ导联、AVF导联S波幅显著升高，主要呈rS波型;超微结构显示肌原纤维部分断裂、线粒体体积增大为特征；而右 心室病变较轻。低温处理3周、4周后左右心室肌微丝受损, 肌原纤维Z线模糊或消失,线粒体明显肿胀,严重者出现空泡样变，左心室的病理变化比右心室重。研究发现低温处理后肉鸡 右心功能减退，左右心室病理组织学变化有所不同，提示低温处理后肉鸡早期左心主要呈 代偿性变化，中期右心出现代偿功能变化，左心代偿功能增强，而后期左心室出现失代偿的 病变，左心室病变可能对肉鸡腹水症的形成有直接影响。