Search results for "Ultrastructure"
showing 10 items of 224 documents
Congenital myopathies with inclusion bodies: a brief review
1998
Abstract Based on morphological abnormalities, congenital myopathies can be classified into several categories: (1) enzyme histochemically abnormal appearance without structural pathology, e.g. congenital fibre type disproportion or congenital fibre type uniformity; (2) abnormally placed nuclei, e.g. myotubular and centronuclear myopathies; (3) disruption of normal intrinsic structures, largely sarcomeres, e.g. central cores and minicores; (4) abnormal inclusions within muscle fibres. Several such inclusions are derived from pre-existing structures, most notably rods or nemaline bodies. Other derivatives of Z-band material are cytoplasmic bodies and possibly related inclusions as spheroid b…
Encapsulation Response ofCiona intestinalis(Ascidiacea) to Intratunical Erythrocyte Injection
1996
Previous studies on the ascidian Ciona intestinalis have shown that an encapsulation response is experimentally induced by inserting vertebrate erythrocytes into the tunic, which initiates a massive inflammatory cell infiltration to isolate the injured area. Several hemocytes contribute to capsule formation, destruction of the foreign cells, tunic regeneration, and wound healing. The fine features of some inflammatory cell types are described although the complete capsular structure is not yet reported. Accordingly, the present investigation further examines various aspects of this cellular reaction against erythrocytes and, for the first time, presents the involvement of extratunical circu…
Tumorspecific Antigens in Human Renal Cell Carcinoma: Ultrastructural Localization of the Antigen by Immune-Electron-Microscopy
1987
In clinical oncology, tumor markers are a valuable tool in therapy monitoring of tumor patients as well as for primary diagnosis. In renal cell carcinoma a number of tumor associated antigens were described which may also be expressed in normal kidney epithelium (Bander et al. 1983; Bander 1984; Moon et al. 1982; Oosterwijk et al. 1987a, b; Ueda 1981). Only occasionally are antigens described which do not react in normal kidney tissue. The here described antigen is restricted to well differentiated human renal cell carcinoma (RCC) and does not show any expression in the normal kidney or other human organs (Table 1). The antibodies produced by hybridoma-technology are highly specific for the…
The precocious commitment of wing Anlagen in Tenebrio molitor revealed by the addition of 20-hydroxyecdysone.
1992
Abstract An injection of 20-hydroxyecdysone (10 μg per animal) 6–13 days after the moult of the last larval instar of Tenebrio molitor induces the development of prothetelic larvae and larval-pupal intermediates. The state of larval-pupal switchover, or commitment, is only disclosed at the time of injection of the moulting hormone. Prothetelic A and B larvae, with small and medium sized wing Anlagen, undergo another larval or pupal instar. Prothetelic C larvae with bigger Anlagen are unable to moult, but the adult programme is expressed. Ecdysed larval-pupal intermediates give more or less perfect adults, while unecdysed mealworms, imprisoned in their larval cuticle, also expressed the adul…
Effects of Tributyltin(IV) Chloride Exposure on Larvae ofCiona intestinalis (Urochordata): An Ultrastructural Study
1996
The effects of tributyltin(IV) chloride (TBT chloride) have been tested on embryos of the ascidian Ciona intestinalis, at two different stages of development: (1) before hatching (coiled larval stage) and (2) 2 h after hatching (swimming larval stage). In vivo observations carried out with a light microscope showed that embryos at the coiled larval stage did not hatch following exposure to TBT chloride. Severe anomalies in the swimming larva, mainly concerning the morphology of the tail, which appeared twisted and squatter than in the controls, were observed. Such anomalies were also found at a functional level, i.e. contractile movements were poor so that the larvae appeared motionless. Ul…
The filter apparatus of Rana temporaria and Bufo bufo larvae (Amphibia, Anura)
1985
In larvae of Rana temporaria and Bufo bufo the location of filter apparatus within the larval organization, the arrangement of the morphological parts as branchial food trap, ventral velum, and filter rows, as well as their surface anatomy, are similar to that of other species of Orton's larval type IV. The means by which mucous with its entrapped food particles is transported from the filter rows to the esophagus is finally resolved. The dorsally positioned ciliary cushion extends far ventrally between the filter plates. From their contact with the filter rows, the cilia transport the mucous to Kratochwill's caudally positioned “Flimmerrinne” and from there to the esophagus. The original c…
Ultrastructure of alcoholic hyalin and fate of the affected hepatocytes
1977
In liver biopsy specimens, foci of satellitosis, i.e., foci of alcoholic hyalin containing hepatocytes surrounded by accumulated leukocytes, were studied by means of electron-microscopic investigation. Within satellitosis hepatocytes, the same morphologic variants of alcoholic hyalin were observed as formerly described in nonsatellitosis liver cells: (1) clusters of randomly oriented smooth filaments of homogenous electron density, (2) bundles of filaments aligned in parallel arrays and exhibiting irregular densities and indistinct boundaries, and (3) masses of a strongly osmiophilic amorphous material, presumably lipidic in nature. The individual hyalin body was composed of one, two, or al…
Cellular composition and organization of the spinal cord central canal during metamorphosis of the frogXenopus laevis
2017
Studying the cellular composition and morphological changes of cells lining the central canal during Xenopus laevis metamorphosis could contribute to understand postnatal development and spinal cord regeneration. Here we report the analysis of central canal cells at different stages during metamorphosis using immunofluorescence for protein markers expression, transmission and scanning electron microscopy and cell proliferation assays. The central canal was regionalized according to expression of glial markers, ultrastructure, and proliferation in dorsal, lateral, and ventral domains with differences between larvae and froglets. In regenerative larvae, all cell types were uniciliated, have a…
Species complexes and phylogenetic lineages of Hoferellus (Myxozoa, Cnidaria) including revision of the genus: A problematic case for taxonomy
2015
Background Myxozoans are metazoan parasites whose traditional spore morphology-based taxonomy conflicts DNA based phylogenies. Freshwater species of the genus Hoferellus are parasites of the excretory system, with several members infecting food and ornamental fish species, as well as amphibians. This study aims to increase our understanding of their molecular diversity and development, aspects about which little is known, and to generate a molecular diagnostic tool to discriminate between different pathogenic and non-pathogenic Hoferellus spp. Methods SSU and ITS rDNA phylogeny, along with morphological descriptions using light and electron microscopy were used to identify and characterize …
Polyurethane and PTFE membranes for guided bone regeneration: histopathological and ultrastructural evaluation.
2010
Made available in DSpace on 2013-08-12T18:17:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Made available in DSpace on 2013-09-30T18:35:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:04:24Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T14:04:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Objective: The purpose of this study was to research a membrane material for use in guided bone regeneration. Study design: In this study, 25 male Wistar rats were used to analyze the biocompatibility and degradation process of biomembranes. The morphol…