Relationship between ultrastructure and specific functions of macrophages

The main function of the macrophages, which is to ingest and degrade any foreign molecules or particles penetrating the organism, appears in the development of the different structures implicated in endocytic activity. The macrophage's high endocytic property first appears in its irregular shape and the large number of extensions of the cell membrane, allowing the rapid capture of extra-cellular material. Adhesion between macrophage cell surface and molecules or particles is greatly enhanced by the presence of varied kinds of receptors: lectin-like receptors which bind specific sugars or highly specific receptors such as Fc and C3b receptors, which increase phagocytosis of opsonized microbes. The microbicidal properties reside in part in the production of superoxide anions which result from the activity of a NAD(P)H oxidase. This enzyme is located in the plasma membrane. Its activity could be demonstrated with a cytochemical method, on the cell surface and along the phagosome membrane. It is, however, very weak in resident macrophages and increases after stimulation or activation. The second kind of bactericidal property corresponds to cationic proteins located in lysosomes. After fusion between lysosomes and phagosomes, they contribute to microbe killing by permeabilizing microbe envelopes. Lysosomes, which contain diverse acid hydrolases and are responsible for the degradation of ingested material, play a crucial role in macrophage endocytic activity. Their number increases in parallel with endocytic activity during macrophage differentiation and is particularly high after ingestion of degradable material. Contrary to polymorphonuclear leukocytes, macrophage is very poor in granules containing peroxidase. The latter, which are rather abundant in monocytes, disappear during macrophage maturation. They do not seem thus to be implicated in macrophage microbicidal activity. Endocytosis is accompanied by rapid and intense exchanges between the different membrane compartments of the cell (plasma membrane, pinosomes or phagosomes, endosomes, lysosomes, Golgi apparatus, etc.). These exchanges seem to occur by transitory fusions between vesicles coming from different compartments, rapidly followed by their recycling to their original compartment. This system of membrane shuttle has been clearly observed after formation of phagosomes or pinosomes in which the internalized plasma membrane is recycled back to the cell surface within a few minutes after their formation. This membrane traffic is especially intense in macrophages, the endocytic activity of which is very high, but it also exists in all cell types.(ABSTRACT TRUNCATED AT 400 WORDS)     

不同熟期桃果实超微结构及相关代谢的研究

实验研究了不同熟期的大久保桃果肉超微结构变化、果实成熟过程中的乙烯释放规律、Ｌｏｘ酶活性、ＰＧ酶活性变化规律以及相关代谢。结果表明:(１)桃果实超微结构的成熟衰老变化先于乙烯高峰的出现和ＰＧ酶活性的快速上升,但乙烯、ＰＧ仍然是影响超微结构衰老变化的重要因素。(２)Ｌｏｘ可能是引起超微结构前期变化的因素。     

山羊蠕形螨组织化学及致病力的研究

运用组织化学法检测雌性山羊蠕形螨体内生化物质的分布。致病力研究，光镜见该螨均聚居真皮深层结节中，主要病变是血管扩张，血管周和真皮中有大量炎性细胞浸润；网状、胶原和弹性纤维不同程度减少。透射电镜见表皮层变化不明显，中、重度感染者基底细胞变性，基底膜损坏，黑色素细胞增生；各种感染度的真皮均见巨噬细胞、淋巴细胞、单核细胞和嗜碱性粒细胞；血管周和神经纤维处发生炎性细胞浸润反应。     

Pubertal Development of Intersertoli Cell Junctions in the Testis of Corriedale Ram Lambs

The ultrastructure of the tight junctional complex of pubertal ram lamb Sertoli cells was studied in immersion-fixed samples and related to clinical data and a light microscopical classification of the degree of spermatogenesis attained in the corresponding seminiferous tubule. Although the process followed the general mammalian developmental trend for tight junction complex formation, 2 unusual ultrastructural features were detected: the presence of an active Golgi complex during the early stage of tight junction formation and the transitory presence of ribosomes on both faces of the ectoplasmic cisternae bordering the developing junctions. The significance of these findings is discussed.     

高邮鸭蛋壳超微结构观察

高邮鸭蛋壳的扫描电镜观察表明,由内向外可将蛋壳分为壳膜层、乳锥层、柱状层、表面晶体层和表层。青壳蛋与白壳蛋在超微结构上存在显著差异,从而导致青壳蛋的蛋壳强度明显高于白壳蛋。     

硅对盐胁迫下库拉索芦荟叶绿素荧光参数和叶绿体超微结构的影响

 以7叶龄幼苗为试材, 研究了可溶性硅( Si) 对盐(NaCl) 胁迫下库拉索芦荟(Aloe vera L. )叶绿素荧光参数和叶绿体超微结构的影响。结果表明, 随处理时间延长, 芦荟对NaCl (100 mmol/L) 胁迫的响应愈加明显, 胁迫30 d的伤害明显重于10 d, 但NaCl胁迫下加Si (2.0 mmol/L) 与不加Si相比, 叶绿素(Chl1) 总含量下降幅度小, Chl1a含量显著提高, 叶绿素初始荧光( Fo) 值的上升与可变荧光( Fv)值的下降受到抑制, 光系统Ⅱ ( PSⅡ) 潜在活性( Fv/Fo) 显著增强, 同时, 加Si有利于保持盐胁迫下芦荟叶绿体的形态, 保护类囊体的超微结构, 说明施Si缓解盐胁迫对光合细胞器的伤害, 可改善盐胁迫下芦荟的光合作用。     

山羊乳腺上皮细胞的分离、培养与超微结构观察

从山羊乳腺取部分组织进行细胞培养，并通过控时消化分离纯化山羊乳腺上皮细胞，建立了山羊乳腺上皮细胞系。结果表明：用含150U／mL Ⅰ型胶原酶和100U／mL透明质酸酶的混合液，37℃消化组织块4h，可得到大量的分散单细胞用于原代培养，该法是获得山羊乳腺组织单细胞的适宜方法；以含10％胎牛血清和双抗的RP-M11640或DEME／F12培养液为基础液，在培养液中添加氢化考的松、胰岛素样生长因子-Ⅰ(IGF-Ⅰ)、表皮生长因子(EGF)及胰岛素一转铁蛋白一硒钠(ITS)对山羊乳腺上皮细胞的生长具有较明显的促进作用。上皮细胞显微和超微结构显示：山羊乳腺上皮细胞在体外培养过程中可形成岛屿状单层聚集和类似圆顶状的结构；传代培养到第7代的细胞仍增殖旺盛，细胞内有丰富的脂滴和高尔基小泡，细胞分泌活动旺盛。     

禽副粘病毒型鹅源分离株YG_(97)和鸡源分离株Y_(98)在体外培养细胞中的形态发生

用禽副粘病毒型鹅源分离株YG97和鸡源分离株Y98的鸡胚尿囊液毒感染原代CEF,制作超薄切片,运用透射电镜观察,结果显示,2株病毒引起CEF细胞器肿胀等轻微的超微结构改变,但不引起细胞的皱缩和裂解。结果表明鹅源YG97分离株和鸡源Y98分离株与NDV强毒株F48E8在致细胞病变特性上的差异。透射电镜观察结果还表明鹅源分离株YG97、鸡源分离株Y98在培养细胞上的形态发生与鸡新城疫病毒F48E8强毒株相似,是由细胞核复制的“纤丝样”结构出核孔在细胞浆内发育而成的。     

猪雌性生殖道黏膜显微和超微结构观察

应用组织学方法和电镜技术研究了雌性成年猪生殖道黏膜显微和超微结构的特征。试验选用成年长白×大约克夏二元杂交母猪20头,通过光镜和透射电镜分别观察了母猪的输卵管、子宫和阴道的黏膜结构特征。结果显示成年母猪的生殖道黏膜由上皮、固有膜和黏膜肌层等构成,输卵管、子宫角、子宫体和子宫颈黏膜的上皮为单层柱状上皮,上皮的游离面含有纤毛和微绒毛,固有膜和上皮间含有丰富的淋巴细胞。淋巴细胞在上皮内移行过程中由胞质伸出许多伪足,淋巴细胞的胞质中主要含有线粒体和高尔基体。母猪生殖道黏膜内的淋巴细胞在某些部位聚集形成淋巴细胞群,特别是子宫角和子宫颈黏膜中较多,淋巴细胞向子宫腔内移行呈现“腔排”现象。结果显示猪雌性生殖道黏膜中含有较多的淋巴细胞,生殖道黏膜可能是黏膜免疫的诱导位点。