Because vertebrate neuromuscular junctions are readily accessible for experimental manipulation, they have provided a superb model in which to examine and test functional correlates of chemical synaptic transmission. In the neuromuscular synapse, acetylcholine receptors have been localized to the crests of the junctional folds and visualized by a variety of ultrastructural techniques. By using ...

The fluorescent binding of tamoxifen to eosin is used on Papanicolaou-stained smears as a marker of cell responsiveness to the antiestrogen molecule. Forty-two cases of human breast carcinomas were submitted to tamoxifen treatment between first diagnosis and surgery (4 to 30 days). Tamoxifen-induced fluorescence is observed in 17 of 42 cases (40%). There is a highly significant correlation betw...

Comparison of ultrastructural and biochemical response to adrenocorticotropic hormone (ACTH) in superfused adrenals or cell suspension and in adrenals of hypophysectomized rats showed that (a) steroidogenic response can take place in superfused glands that have suffered gross structural damage and contained no detectable intact mitochondria; (b) steroidogenesis of cell suspensions takes place w...

The role of endothelin-1 (ET-1) and of its receptor A (ETA) blockade in oedematous acute pancreatitis (AP) remains unclear. In 40 male Wistar rats with i.p. cerulein-induced AP, lasting 4 hours, ET-1 2x0.5 nmol/kg and 2x1.0 nmol/kg or selective ETA antagonist LU 302146, 10 mg/kg and 20 mg/kg was given i.p. simultaneously with cerulein. Histological and ultrastructural studies of pancreatic spec...

The contractile characteristics, fatiguability, and ultrastructure were examined in individual twitch skeletal muscle fibres dissected from the iliofibularis muscle of frog Rana temporaria in order to define if an explicit correspondence exists between physiological and morphological features in different types of muscle fibres. Three groups of twitch fibres were distinguished in the study acco...

Transport proteins are essential for cells in allowing the exchange of substances between and their environment across lipid bilayer forming a tight barrier. Membrane lipids modulate function transmembrane such as transporters two ways: Lipids tightly specifically bound to transport addition they from bulk proteins. This overview summarizes currently available information at ultrastructural lev...

The use of immunohistochemistry and, more recently, molecular methods has seen a sharp reduction of the role of electron microscopy in the diagnosis of soft tissue sarcomas (1,2). Ultrastructural analysis, however, does continue to play a useful role in selected cases. The focus in this presentation is on adult soft tissue tumors; Dr. John Hicks will follow with a presentation on avoiding pitfa...

Fixation with 4% formaldehyde/24 hours, 1% formaldehyde and 1% glutaraldehyde/1-1.5 hours and 1-1.5% glutaraldehyde/1-1.5 hours provided satisfactory ultrastructural conservation of the tissues. None of these fixatives appeared to denature IgG globulins, but formation of cross-linkages prevents conjugates from reaching antigenic sites. Weak aldehyde fixation may enhance penetration of conjugate...

An ultrastructural study was performed to identify any differences in fine detail between type III and IV gastric polyps, which seem to differ from each other because they have different histological features and malignant potential. Clear ultrastructural differences were found, implicating microvilli, mucous granules, interdigitations, ribosomes, mitochondria and nuclei. Although these two sub...

OBJECTIVE This study was undertaken to evaluate structural and ultrastructural characteristics of the mucosa of neovaginae created by Vecchietti's laparoscopic operation for Rokitansky syndrome. STUDY DESIGN Vaginoscopy and Schiller test were performed 3, 6, and 12 months after the operation in 106 patients. A biopsy specimen of the neovagina obtained 12 to 18 months after surgery in 19 patie...