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

A light- and electron-microscopic study of the pineal complex of the ammocoete larva of the southern lamprey Geotria australis. 南方七鳃鳗ammocoete幼虫松果体复合体的光学和电子显微镜研究。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1992-06-01

V B Meyer-Rochow, D Stewart

引用次数: 0

Leaf ruminal digestion in Sorghum bicolor cultivars as influenced by water deficit. 水分亏缺对双色高粱叶片瘤胃消化的影响。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1992-06-01

J J Villalba, H E Laborde, H M Arelovich

引用次数: 0

Dehydroleucodine prevents ethanol-induced necrosis in the rat gastric mucosa. A histological study. 去氢芥碱对乙醇致大鼠胃黏膜坏死有预防作用。组织学研究。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1992-06-01

R S Piezzi, J A Guzman, T Guardia, M J Pestchanker, E Guerreiro, O S Giordano

{"title":"Dehydroleucodine prevents ethanol-induced necrosis in the rat gastric mucosa. A histological study.","authors":"R S Piezzi, J A Guzman, T Guardia, M J Pestchanker, E Guerreiro, O S Giordano","doi":"","DOIUrl":"","url":null,"abstract":"The aerial part of Artemisia douglasiana Besser (6) has been used in folk medicine as a cytoprotective agent against the development of peptic ulcer. The dehydroleucodine (DhL), its active principle, significantly prevents the formation of gastric lesions induced by the exposure of the rats to absolute ethanol orally administered. The stomachs of control and experimental rats (after ethanol and pretreated with DhL) were removed, opened along the greater curvature and studied under stereo microscope and with light and scanning electron microscope. Absolute ethanol produced focal visible hemorrhagic lesions, extensive hyperemia, vascular stasis, cell disruption, and necrosis of the mucosa. Abundant mass of mucus was observed with scanning. The stomachs of rats pretreated with DhL showed a reduction of lesions. No hemorrhage and hyperemia were observed. The epithelia of the mucosa had a cobblestone appearance, similar to control rats and was covered by a fine layer of mucus. The mechanism of the protective action of DhL is unknown although it seems to be related to endogenous prostaglandins (PG).","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"16 1","pages":"45-55"},"PeriodicalIF":0.0,"publicationDate":"1992-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12468056","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

Crystals in supporting cells of pineal organ in larval lamprey not likely to be pure guanine. 七鳃鳗幼虫松果体器官支持细胞中的晶体不太可能是纯鸟嘌呤。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1992-06-01

V B Meyer-Rochow, D Stewart

引用次数: 0

Testicular organization and spermatogenesis in Tegula (Chlorostoma) tridentata (Potiez and Michaud, 1838) (Mollusca: Archaeogastropoda: Trochidae). 三齿鲸(Tegula (Chlorostoma) tridentata)的睾丸组织和精子发生(Potiez and Michaud, 1838)(软体动物:古腹足目:滑足科)。

Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular Pub Date : 1992-06-01

D I Brown

{"title":"Testicular organization and spermatogenesis in Tegula (Chlorostoma) tridentata (Potiez and Michaud, 1838) (Mollusca: Archaeogastropoda: Trochidae).","authors":"D I Brown","doi":"","DOIUrl":"","url":null,"abstract":"The basic environment for the generation of spermatozoa in the gastropods is a gametogenic compartment resulting from somatic and germ cells interaction. In arachaeogastropods however, such association has not been characterized. In this study at the light and transmission electron microscopy level, evidences are given that in T. (C.) tridentata, spermatogenesis is centrifugal and occurs around seminiferous tubules surrounding the lumen that is a blood vessel. This basic organization presents somatic cells interacting with germ cells. There are three types of spermatogonia: primary spermatocytes with proacrosomic granules, and spermatids that undergo the following spermiohistogenic events: 1. Nuclear chromatin condensation to form a short cylindrical nucleus with an anterior invagination containing the base of the axial rod and a posterior invagination containing the proximal centriole. 2. Polarization of mitochondria attached to the posterior nuclear membrane to integrate the midpiece. 3. Coalescence of proacrosomic granules in one acrosomic vesicle, polarization of the acrosomic vesicle in the anterior nuclear region and transformation of the acrosomic vesicle in the conical acrosomic complex with a subacrosomic cavity containing the axial rod. 4. Tail formation from the distal centriole. Apparently the supporting cells do not associate closely with the spermatids. Therefore, they would not perform a mechanical role in the generation of spermatozoa shape that is characteristic of the Trochidae and other archaeogastropod families. This spermatozoon is peculiar due to its prominent acrosome larger than the nucleus.","PeriodicalId":77265,"journal":{"name":"Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular","volume":"16 1","pages":"17-33"},"PeriodicalIF":0.0,"publicationDate":"1992-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12468210","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

Structural and cytochemical study of the rat exocrine pancreas treated with dl-ethionine. I. Multilayered bodies and lesioned areas. dl-乙硫氨酸处理大鼠外分泌胰腺的结构和细胞化学研究。1 .多层体和病变区域。

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

C J Rodrigues, A J Rodrigues Júnior, A Sesso

{"title":"Structural and cytochemical study of the rat exocrine pancreas treated with dl-ethionine. I. Multilayered bodies and lesioned areas.","authors":"C J Rodrigues, A J Rodrigues Júnior, A Sesso","doi":"","DOIUrl":"","url":null,"abstract":"The fine structural changes and the reactivity for acid phosphatase (AcPase) and thiamine pyrophosphatase (TPPase) were studied in thin sections from rat pancreatic acinar cells exposed to dl-ethionine for 2-10 days. The cells from ad libitum and pair-fed controls exhibit occasionally 0.2-0.6 microns circular profiles showing reaction for AcPase and considered as presumptive lysosomes. At days 2 and 4 of dl-ethionine treatment the acinar cells exhibit presumptive lysosomes, autophagosomes and membrane-bounded cytoplasmic areas devoid of electron density and AcPase activity, containing scattered membranous elements. These regions were named lesioned areas. On 6th, 8th and 10th days a membrane bound anomalous cytoplasmic structure that represents a dense pile of layered membrane-like material (multilayered bodies, MB) was seen. The MBs consistently show AcPase activity and in rare instances TPPase activity. Freeze fracture studies reveal that the limiting membrane of the MBs has intramembranous particles whereas the multilayered membranous contents are devoid of such particles. The structure and disposition of the lamellae of the MBs seen in the replicas are similar to those of artificially prepared phospholipidic membranes.","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 2","pages":"179-91"},"PeriodicalIF":0.0,"publicationDate":"1991-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13006600","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

Distribution of actin, actin-binding proteins, 43K protein, and spectrin in D. tschudii electrocytes. 肌动蛋白、肌动蛋白结合蛋白、43K蛋白和谱蛋白在弓形蝶电细胞中的分布。

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

A Vidal, M P Figueroa, F J Barrantes

{"title":"Distribution of actin, actin-binding proteins, 43K protein, and spectrin in D. tschudii electrocytes.","authors":"A Vidal, M P Figueroa, F J Barrantes","doi":"","DOIUrl":"","url":null,"abstract":"With a view to establishing the location of proteins related to the nicotinic cholinergic receptor (AChR), immunocytochemical studies were carried out in the electric tissue of the South American ray Discopyge tschudii. The receptor protein was localized at the innervated, ventral region of the electrocyte in cryostat sections using Texas Red-labelled alpha-bungarotoxin, a specific AChR marker. A series of antibodies against actin and actin-associated proteins (alpha-actinin, vinculin, tropomyosin and spectrin) were also employed in indirect immunofluorescence assays. Furthermore, with the aid of the monoclonal antibody 1234A, the peripheral, nonreceptor 43K protein was found to be colocated with the AChR and spectrin at the ventral surface of the electrocyte. NBD-phallacidin was used to detect the filamentous form of actin or F-actin. The anti-actin antibody recognized epitopes throughout the electrocyte cytoplasm. F-actin was mainly distributed at the dorsal, non-innervated region, where alpha-actinin, vinculin and tropomyosin were also localized. The results indicate a) the existence of a close structural relationship between the 43K protein, spectrin, and the AChR at the ventral, innervated face of the electrocyte; b) the occurrence of an actin isoform probably mono or oligomeric-throughout the electrocyte's cytoplasm, and c) the possible association of F-actin, localized at the dorsal region of the electrocyte, with alpha-actinin, tropomyosin and vinculin, as in other cellular systems.","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 2","pages":"193-205"},"PeriodicalIF":0.0,"publicationDate":"1991-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13006601","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

Effect of Test-yolk upon human sperm acrosome reaction. 卵黄对人精子顶体反应的影响。

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

R D Moreno, C Barros

{"title":"Effect of Test-yolk upon human sperm acrosome reaction.","authors":"R D Moreno, C Barros","doi":"","DOIUrl":"","url":null,"abstract":"Human spermatozoa stored in Test-yolk buffer show an increased rate of fusion with zona-free hamster oocytes as compared with freshly ejaculated spermatozoa. Therefore, in this work, we studied the kinetics of the acrosome reaction and fertilization using fresh and TEST-yolk stored human spermatozoa in order to determine whether the rate fertilization was related to the rate of acrosome reaction. The semen samples were divided in two aliquots, one was used fresh (control) and the other stored for 48 hours at 4 degrees C in TEST-yolk buffer (experimental). Spermatozoa of each aliquot were evaluated every two hours for: a) the incidence of acrosome reaction, as studied by scanning electron microscopy, and b) their ability to fuse with zona-free hamster oocytes. The results showed that--as a function of the incubation time--there was an increase in the percentage of acrosome reaction, both in controls (zero to 28.3%) and in the experimental ones (5 to 27.8). It was also found that there were no significant differences between the incidence of the acrosome reaction when using fresh or TEST-yolk treated spermatozoa. On the other hand the rate of fertilization was significantly (p < 0.05) higher when TEST-yolk stored (experimental) spermatozoa were used as compared with the use of fresh (control) spermatozoa. These results suggest that the increase in the rate of fertilization when using TEST-yolk stored spermatozoa is not associated with an increase in the rate of the acrosome reaction, but most probably to an improvement in the efficiency of the gamete membrane fusion.","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 2","pages":"following 211"},"PeriodicalIF":0.0,"publicationDate":"1991-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13006603","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

Antibodies from Chagas patients serum bind to the gut epithelial cell surface of Triatoma infestans. 从恰加斯病患者血清中提取的抗体可与感染三角瘤菌的肠道上皮细胞表面结合。

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

L S Gutierrez, M H Burgos, S D Brengio

引用次数: 0

Scanning electron microscopy of the granular layer of rat cerebellar cortex. 大鼠小脑皮层颗粒层的扫描电镜。

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

G Apergis, T Alexopoulos, M Mpratakos, T Katsorchis

引用次数: 0