Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular最新文献_第2页

Ultrastructure of the nerve endings in the rat tongue mucosa. 大鼠舌黏膜神经末梢的超微结构。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1991-12-01

I Watanabe, C Ide

引用次数: 0

Chronic lead exposure induces alterations on local circuit neurons. 慢性铅暴露可引起局部回路神经元的改变。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1991-06-01

A Selvin-Testa

{"title":"Chronic lead exposure induces alterations on local circuit neurons.","authors":"A Selvin-Testa","doi":"","DOIUrl":"","url":null,"abstract":"The effect of chronic lead exposure in neonatal rats was examined, particularly on hippocampal local circuit neurons (LCN). Chronic lead was administered to rat pups in the first week of life through the mother milk. During the lactation period the mother only drank water containing 1 g% lead acetate (w/v) -subclinical dose. Following weaning, the young rats were treated for 3 months with the same concentration of lead-adulterated water. Electron microscopy studies were made at 30, 45, 60, 75 and 90 days of age. After 2 months of lead exposure, irregular outline and dark-condensed cytoplasm in non-pyramidal neurons, in basket and in granule cells were found. Within the neuropil, some beaded and smooth dendrites, as well as some axons and synaptic terminals, appeared condensed and darker than the surrounding elements. Coincident with the LCN alterations, astrocytes showed an increment of glial filaments. These results suggested that the functional activity of LCN could be modified by the observed changes. Such ultrastructural modifications could be a morphological substrate for the subtle neuropsychological deficits of rats chronically exposed to relatively low concentration of lead.","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"15 1","pages":"25-39"},"PeriodicalIF":0.0,"publicationDate":"1991-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13003082","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

Patterns of transient expression of the arenavirus nucleocapsid protein gene in transfected cells. 沙粒病毒核衣壳蛋白基因在转染细胞中的瞬时表达模式。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1991-06-01

R V Rivera Pomar, E M Manzella, P D Ghiringhelli, O Grau, V Romanowski

{"title":"Patterns of transient expression of the arenavirus nucleocapsid protein gene in transfected cells.","authors":"R V Rivera Pomar, E M Manzella, P D Ghiringhelli, O Grau, V Romanowski","doi":"","DOIUrl":"","url":null,"abstract":"The cloned genes for the nucleocapsid proteins N of Junín and LCM (lymphocytic choriomeningitis) arenaviruses were inserted into the SV40-derived expression vector designated pKG4. When BHK-21 (baby hamster kidney fibroblasts) and CV-1 (African green monkey kidney fibroblasts) cell lines were transfected using these constructions, the transient expression yielded a polypeptide that could not be distinguished either by size nor by immunoreactivity from the N protein synthesized during the viral infection. The immunofluorescence analysis showed a pattern of intracellular localization similar to that observed in virus infected cells, i.e. varying from a diffuse cytoplasmic staining to granules, either distributed throughout the cytoplasm or concentrated in the perinuclear region. The association of the N protein with basophilic granules is similar to that observed in the cytopathic effect caused by arenaviruses, and could be related to the physicochemical properties of this polypeptide containing numerous basic amino acid sequences, that would allow for the interaction with cellular RNAs.","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"15 1","pages":"41-55"},"PeriodicalIF":0.0,"publicationDate":"1991-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12834031","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

Spermatozoon maturation in vertebrates with internal fertilization. 脊椎动物体内受精的精子成熟。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1991-06-01

P Esponda

{"title":"Spermatozoon maturation in vertebrates with internal fertilization.","authors":"P Esponda","doi":"","DOIUrl":"","url":null,"abstract":"Sperm maturation occurs in the mammalian spermatozoon during its passage through the epididymis. Maturation comprises a series of morpho-physiological changes, which includes the acquisition of the fertilizing capacity in the gamete. This maturative process has been particularly studied in mammals, but different data reveal that birds, reptiles and some kind of fish have a similar characteristic. Anatomical and histological analyses of mammalian epididymis and of Wolffian ducts of some birds and reptiles show the predominance of a secretory cell system. Proteins secreted by the male ducts seem to be an important factor involved in the acquisition of motility, as well as in the changes in the molecular organization of the plasma membrane. Changes occurring in the plasma membrane of the mammalian spermatozoon are related to the acquisition of foreign proteins (of epididymal origin). Some of these membrane changes seem to be connected with the capacitation phenomena and also with gamete interaction during fertilization. The use of antibodies against Wolffian duct proteins has shown that spermatozoa birds and reptiles also acquire proteins during their passage through the male duct. Nevertheless, in birds, and probably in reptiles, capacitation is not a pre-requisite for fertilization and some testicular spermatozoa are able to fertilize the egg. Then, what is the real significance of the membrane maturative changes in these subtherian vertebrates? Proteins acquired during maturation in such species must have different functions from those in mammals, to support spermatozoon survival and/or transport in the female tract, where spermatozoa are stored for a long time. Surface changes in mammals would possibly have similar roles when the gametes are in the female tract.","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"15 1","pages":"1-23"},"PeriodicalIF":0.0,"publicationDate":"1991-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13003081","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

Interaction of Trypanosoma cruzi with macrophages influence of temperature. 克氏锥虫与巨噬细胞的相互作用对温度的影响。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1991-06-01

M H Burgos, E O Zangheri, L S Mayorga, L S Gutiérrez

引用次数: 0

The release of catecholamines by an endogenous factor that inhibits neuronal Na+,K(+)-ATPase. 抑制神经元Na+，K(+)- atp酶的内源性因子释放儿茶酚胺。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1991-06-01

G Rodríguez de Lores Arnaiz, A Pellegrino de Iraldi

{"title":"The release of catecholamines by an endogenous factor that inhibits neuronal Na+,K(+)-ATPase.","authors":"G Rodríguez de Lores Arnaiz, A Pellegrino de Iraldi","doi":"","DOIUrl":"","url":null,"abstract":"It is known that the inhibition of Na+,K(+)-ATPase induces neurotransmitter release in several experimental models. In this laboratory it was previously observed that a brain soluble fraction separated by Sephadex G-50 (peak II) is able to inhibit Na+,K(+)-ATPase but not other membrane-bound enzymes. The object of the present study was to test the effect of brain peak II fraction on neurotransmitter content of the pineal nerves synaptic vesicles. Uninjected rats and rats injected 30 min before with 5-hydroxydopamine (30 mg per kg,i.p.) were used. 5-hydroxydopamine produces a false neurotransmitter whose presence in the synaptic vesicles is visualized after fixation with glutaraldehyde-osmium as an electron dense material with the electron microscope which fills totally or partially the vesicles. In uninjected rats the osmiophilia and the chromaffin reaction of the electron dense core were studied. The pineal glands were incubated in Tyrode solution without calcium in the presence and absence of peak II at room temperature and processed for electron microscopy. When the glands from rats pretreated with 5-hydroxydopamine were incubated with peak II a significant decrease in the number of vesicles totally stained was observed. This indicates a reduction in false neurotransmitter content, specially in the matrix of the synaptic vesicles. In the presence of an aged peak II, which does not inhibit Na+,K(+)-ATPase, this effect on the synaptic vesicles was not observed. When the glands from uninjected rats were incubated with peak II no changes in the osmiophilia and the chromaffin reaction of the synaptic vesicles were found. The osmiophilia and the chromaffin reaction of the cores marks the monoamines storage site (catechol and indoleamines in the pineal nerves). These results are coherent with the idea of a relationship between the inhibition of Na+,K(+)-ATPase activity and the release of a pool of neurotransmitter stored in the nerve endings.","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"15 1","pages":"93-105"},"PeriodicalIF":0.0,"publicationDate":"1991-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12852507","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

Action of plasma and liver extract from adult mice on the mitotic activity of young mouse liver. 成年小鼠血浆及肝脏提取物对幼鼠肝脏有丝分裂活性的影响。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1991-06-01

A L García, A M Inda, J M Echave Llanos

引用次数: 0

Secretory granules in rat submandibular acinar cells during experimental Chagas disease. 实验性恰加斯病大鼠颌下腺泡细胞分泌颗粒。

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 B Alves

引用次数: 0

The pineal recess of the opossum: a scanning and transmission electron microscope study. 负鼠的松果体隐窝:扫描和透射电子显微镜研究。

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

R M Cosenza, J A Sousa Neto, A B Machado

{"title":"The pineal recess of the opossum: a scanning and transmission electron microscope study.","authors":"R M Cosenza, J A Sousa Neto, A B Machado","doi":"","DOIUrl":"","url":null,"abstract":"Scanning and transmission electron microscope studies were performed in the pineal recess region of eighteen adult Didelphis albiventris opossums. With the scanning electron microscope, three concentric regions could be observed in the pineal recess: a central zone lined by cells free of cilia or microvilli, or by a meshwork of interdigitating cell processes; an intermediate zone lined by microvillous cells; and a peripheral zone, lined by ciliated cells. The transmission electron microscope revealed that the central zone is lined mainly by pinealocytes. The lining cells are frequently overlaid by a meshwork of pinealocytic and glial processes. A \"subsurface labyrinth\" (a meshwork of cellular processes underneath the lining cells) is constantly seen in the central zone. The intermediate zone is lined by elongated microvillous ependymal cells, and the peripheral zone by typical ependyma. The large liquor-contacting area in the pineal recess region, as well as the peculiar organization of its surface, suggest a complex interrelationship between the liquor and the pineal gland of the opossum.","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":"101-13"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289658","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

Sperm association in the rat epididymis. 大鼠附睾中精子的结合力。

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 W Fornes, M H Burgos

引用次数: 0