Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular最新文献_第3页

Localization of sugar-binding proteins in Trypanosoma cruzi using gold-labeled neoglycoproteins. 利用金标记新糖蛋白定位克氏锥虫的糖结合蛋白。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1990-01-01

J Degett, T Souto-Padron, W De Souza

引用次数: 0

Improved prolactin crop-sac bioassay applying a morphometric approach. 用形态计量学方法改进催乳素作物囊生物测定。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1990-01-01

M I Prada, A I Torres, A Aoki

引用次数: 0

Giardia lamblia attachment to biological and inert substrates. 贾第鞭毛虫附着在生物和惰性基质上。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1990-01-01

F Knaippe

引用次数: 0

Ultrastructural study of reaggregated culture of brainstem: synaptogenesis. 脑干再聚集培养的超微结构研究:突触发生。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1990-01-01

E M Lopez, S Peressini, M F Kubke, J A Pecci Saavedra

{"title":"Ultrastructural study of reaggregated culture of brainstem: synaptogenesis.","authors":"E M Lopez, S Peressini, M F Kubke, J A Pecci Saavedra","doi":"","DOIUrl":"","url":null,"abstract":"The synaptogenesis and the morphological differentiation of neural cells were studied in aggregating cultures. Brainstems of 14-15 days old rat embryos were removed and the area located between the mesencephalic flexure and the caudal portion of metencephalon was dissected and mechanically dissociated to single cells. These cells reassociated forming highly organized aggregates in which differentiation took place. Samples were harvested after different time periods, fixed and processed for electron-microscopic study. After one day in culture the aggregates were composed by rounded undifferentiated cells. These cells had a high nuclear/cytoplasmic relation, were devoid of processes and were separated by great intercellular spaces. At the end of the first week of culture cell differentiation and extension of processes were evident. A loose neuropil appeared: it was composed by abundant growing neurites and growth cones. Later, the neuropil became more compact and glial processes and synaptic terminals filled with vesicles appeared. The early appearance of vesicles in the synaptic endings was the first evidence of synaptogenesis. Post and presynaptic membrane densities appeared later, and fully mature synaptic contacts were seen by the end of the 3rd week in culture. Scarce myelin sheaths were observed after 35 days in vitro.","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"14 2","pages":"89-99"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13288928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Colchicine binding to tubulin from brain homogenates in the presence of sugars, glycols and metal ions. Effect of nickel ions on the tubulin solubility. 秋水仙碱与脑微管蛋白在糖、乙二醇和金属离子存在下均质化。镍离子对微管蛋白溶解度的影响。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1990-01-01

W Beron, F Bertini

{"title":"Colchicine binding to tubulin from brain homogenates in the presence of sugars, glycols and metal ions. Effect of nickel ions on the tubulin solubility.","authors":"W Beron, F Bertini","doi":"","DOIUrl":"","url":null,"abstract":"The fact that glycerol preserves microtubules from depolymerizing in vitro, and that some ions such as Ca(II) and Mg(II), regulate the assembly-disassembly process of these structures, induced us to study the effect of several sugars, glycols and metal ions on solubility and colchicine affinity of tubulin in rat brain homogenates, and of purified microtubular protein. Inhibition of colchicine binding was significant with glycerol, polyethylene glycol 1000 (PEG-2) and the ions Al(III), Co(II), Ni(II), while compounds structurally related to glycerol (glucose and sucrose) did not inhibit it. Mannitol, instead, increased the activity a 47% over control. Apparently the presence of some compounds in brain homogenates [PEG-2 (1000) and Ni(II)] favored tubulin sedimentation when these latter were centrifuged at 100,000 x g for 150 min at 20 degrees C, but the form in which tubulin becomes aggregated in the pellet is unknown. Nickel ion made insoluble microtubular protein of homogenates and the purified one by more than 90% without causing significant inhibition of the colchicine binding. The sediment containing nickel-treated two cycles purified microtubular protein observed with the electron microscope did not present microtubules, but it revealed the presence of irregular, wavy and stretched structures bearing highly dense dotted material. The sediments became soluble in phosphate-glutamate buffer (pH 6.8) and, when incubated in polymerizing conditions, gave rise to microtubules undistinguishable from those prepared with untreated purified protein.","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"14 2","pages":"147-57"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13288927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The zona-free hamster oocyte penetration test: a simple procedure using a DNA fluorescent stain to detect the male pronucleus formation. 无带仓鼠卵母细胞渗透试验:使用DNA荧光染色检测雄性原核形成的简单程序。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1990-01-01

J C De Rosas, M W Fornes

{"title":"The zona-free hamster oocyte penetration test: a simple procedure using a DNA fluorescent stain to detect the male pronucleus formation.","authors":"J C De Rosas, M W Fornes","doi":"","DOIUrl":"","url":null,"abstract":"In order to increase the value of the zona-free hamster oocyte penetration test, a comparatively simple and fast method using the fluorochrome Hoechst 33342 was developed. Human spermatozoa were washed and incubated 1 hr medium BWW for capacitation. Hamster oocytes were stripped of cumulus oophorus and zona pellucida with hyaluronidase and trypsin, washed and used immediately. Thirty oocytes were placed in a drop of BWW containing 3,5.10(6)/ml of human spermatozoa under mineral oil. The sperm-oocyte preparation was incubated for 3 hr at 37 degrees C, during the last 15 min of incubation, the fluorochrome Hoechst 33342 (H) was added and incubation was allowed to proceed until the incubation time was over. Observations showed that the female pronucleus, eccentrically placed, gives a bright green-bluish fluorescence whereas chromatin of sperm heads shows different stages of decondensation and also a bright fluorescence. This inexpensive method has given consistent results in a large number of cases and provides an additional new approach to the \"penetration test\" as a proof of the capacity to form a \"male pronucleus\".","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"14 2","pages":"165-71"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12889181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An ultrastructural stereologic study of mitochondria in the neonatal adrenal cortex of the rat. 新生大鼠肾上腺皮质线粒体超微结构体视学研究。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1990-01-01

M Souto, R Bianchi, R S Piezzi

{"title":"An ultrastructural stereologic study of mitochondria in the neonatal adrenal cortex of the rat.","authors":"M Souto, R Bianchi, R S Piezzi","doi":"","DOIUrl":"","url":null,"abstract":"The ultrastructural changes observed during the neonatal period of the rat adrenal cortex are described. The zona juxta-medullaris cells presented round mitochondria with vesicular cristae and large endoplasmic reticulum. Variations on the surface of the mitochondrial cristae were determined by morphometric methods. The cortical cells of 1 and 10-days-old rats showed a well developed endoplasmic reticulum. Morphological analysis indicate that the number of mitochondrial cristae increase the third day, followed by a decrease. At the tenth day a second increase was observed. Plasma corticosterone was also measured. The highest levels of this hormone were found in the 1, 2 and 10-days-old rats. A decrease was observed in rats of 3 to 8 days of age. This result is coincident with the adrenal changes observed in the developing of mitochondria and endoplasmic reticulum in the neonatal period. The increase in the number of mitochondrial cristae in the three-days old rats can be considered a morphological expression of the neonatal gland in the period influenced by maternal dependence. The most important morphological and metabolic changes observed the second week of life are probably due to the maturation of the hypothalamic pituitary axis that stimulates the neonatal adrenal cortex secretion, which is independent of maternal dependence.","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"14 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13258190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanisms underlying the organizer formation in Bufo arenarum embryos. 斗鱼胚胎中组织器形成的机制。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1989-06-01

M E Manes, O L Nieto

{"title":"Mechanisms underlying the organizer formation in Bufo arenarum embryos.","authors":"M E Manes, O L Nieto","doi":"","DOIUrl":"","url":null,"abstract":"In the early gastrula of Bufo arenarum the prospective mesoderm was previously identified as a marginal belt of grey cells. To analyze their differentiation capacity explants of these cells were cultured within ectodermal vesicles, in isolation and in combination with vegetal components. When cultured in isolation, dorsal and ventral fragments from the deep marginal zone behaved differently. Whilst ventral explants produced blood cells, dorsal explants failed to differentiate, remaining as masses of yolk-laden cells. On the other hand, both cultures were drastically modified when associated with superficial cells from the blastoporal zone, which caused the following effects: a) Promotion of differentiation in dorsal marginal explants, able now to produce notochordal and somitic structures, in addition to mesenchymatic cells. b) Promotion of dorsalization in ventral marginal explants, which changed their expected destiny developing axial components, similar to those furnished by \"activated\" dorso marginal explants. On the contrary, combined cultures of animal and vegetal pieces were unable to generate mesodermal structures. These studies suggest that the axial mesoderm, identified as the \"organizer\", develops from a marginal substrate of genuine mesodermal cells through a dorsalizing inductive stimulus originated in superficial periblastoporal cells.","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"13 1","pages":"73-83"},"PeriodicalIF":0.0,"publicationDate":"1989-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13662205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Further studies on the cytoskeleton of resident, stimulated and activated macrophages. 巨噬细胞常驻、刺激和活化细胞骨架的进一步研究。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1989-06-01

L M del Caro, M F de Souza, W de Souza

引用次数: 0

Immunocytochemical localization of serotonin in the pineal gland. 松果体血清素的免疫细胞化学定位。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1989-06-01

M Heredia Chons, J J López Costa, A Pellegrino de Iraldi, J Pecci Saavedra

引用次数: 0