Search results for "Ultrastructure"
showing 10 items of 224 documents
‘Synaptic’ Bodies in the Pineal Glands of the Cow, Sheep and Pig
1990
The present results show that ‘synaptic’ bodies (SB) are a heterogeneous group of organelles in the pineal glands of Artiodactyla. Basically, rod-like (ribbons) and sphere-like (spherules) SB can be distinguished. In the pig small numbers of both ‘synaptic’ ribbons (SR) and ‘synaptic’ spherules (SS) are found. In bovine and ovine pineal glands few SS but no SR were seen. The same results were obtained from animals of the same species but from different continents. This suggests that the numbers of SB are species specific rather than influenced by the different lighting conditions in Europe and in equatorial Africa.
Electron microscopic observation of tonsillar tissue as a diagnostic aid in early juvenile neuronal ceroid-lipofuscinosis.
1987
An electron microscopic observation in a tonsil of a patient with early juvenile neuronal ceroid-lipofuscinosis (NCL) demonstrated characteristic lipopigments in lymphocytes, i.e., fingerprint profiles (FPP) and granular matrixes. While numerous FPP, curvilinear profiles (CLP) and granular matrixes were found in reticulo-endothelial and plasma cells, tonsillar lymphocytes contained only FPP and granular matrixes as seen in circulating lymphocytes. These findings suggest that a tonsil biopsy, an easy and simple technique, may provide more reliable information than a skin biopsy not only for the diagnosis of but also for differentiating the clinical forms of childhood NCL.
Ultrastructural studies of the retina in infantile neuronal ceroid-lipofuscinosis.
1988
A 9-year-old boy who had died of infantile neuronal ceroid-lipofuscinosis had experienced retina-derived visual failure. Ophthalmologically and morphologically, his retina was severely atrophic and scarred by a dense fibrillary gliosis while photoreceptor cells had completely disappeared, cells of the bipolar layer had decreased in number and had become atrophic beyond cytologic recognition. Retinal pigment epithelial cells had undergone either atrophy or proliferation. Disease-specific granular lipopigments had accumulated in perikarya and processes of remaining cells and were infrequently associated with melanin within huge melanolipofuscin bodies and RPE cells of sessile and migrating na…
Method for functional study of mitochondria in rat hypothalamus
2008
1872-678X (Electronic) Journal Article Research Support, Non-U.S. Gov't; Different roles of mitochondria in brain function according to brain area are now clearly emerging. Unfortunately, no technique is yet described to investigate mitochondria function in specific brain area. In this article, we provide a complete description of a procedure to analyze the mitochondrial function in rat brain biopsies. Our two-step method consists in a saponin permeabilization of fresh brain tissues in combination with high-resolution respirometry to acquire the integrated respiratory rate of the biopsy. In the first part, we carefully checked the mitochondria integrity after permeabilization, defined exper…
Species-specific effects of single sensillum ablation on mating position in Drosophila.
2003
0022-0949 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; Dipteran insects show a wide range of species-specific mating positions. Interspecific transitions from one position to another may reflect sexual or natural selection, or be pleiotropic consequences of other genetic changes. Like many cyclorrhaphan flies, Drosophila species mate with the male on the back of the female, positioned centrally. Mechanosensory sensilla on the male genitalia of three species of the melanogaster species sub-group of Drosophila have species-specific effects on mating position and on courtship success: ablation of a single pair of bristles on the genital claspers of D. melanogaste…
Ovarian development of Corynosoma semerme (Acanthocephala) during experimental infections in rats.
1987
SUMMARYThe general structure and aspects of the development of the ovaries of the palaeacanthocephalan Corynosoma semerme were studied by transmission electron microscopy using worms varying in age from 18 to 90 h obtained from experimental primary infections in hydrocortisone-treated rats instead of seals, which serve as the natural definitive hosts. The observations can be interpreted to show that the immature ovaries become transformed relatively rapidly from cellular spheres to the more complex mature ovaries consisting of the supporting and oogonial syncytia and the germ-line cells. The supporting syncytium developed before the oogonial syncytium. The cytological appearance of ovaries …
Tormogen cell and receptor-lymph space in insect olfactory sensilla. Fine structure and histochemical properties in Calliphora.
1978
(1) The basiconic sensilla on the antennae of Calliphora resemble other insect epidermal sensilla; one or several bipolar sense cells are surrounded by three non-neural cells. (2) The apical cell membrane of the tormogen cell (one of the three accessory cells) forms microvilli coated internally with particles. (3) In the (extracellular) outer receptor-lymph space hyaluronic acid can be demonstrated histochemically. (4) Demonstration of non-specific alkaline phosphatase, Mg2+-activated ATPase, and the presence of mitochondria in the apical part of the tormogen cell suggest active transport processes through these cells into the outer receptor-lymph space.
Ultrastructural observations on the central innervation of the guinea-pig pineal gland.
1981
In the present study the central innervation of the guinea-pig pineal gland was investigated. The habenulae and the pineal stalk contain myelinated and non-myelinated nerve fibres with few dense-cored and electron-lucent vesicles. Some myelinated fibres leave the main nerve fibre bundles, lose their myelin-sheaths and terminate in the pineal gland. Although direct proof is lacking, the non-myelinated fibres appear to end near the site where the bulk of the myelinated fibres are located. Here a neuropil area exists where synapses between non-myelinated fibre elements are abundant. Neurosecretory fibres were also seen. The results support the concept of functional interrelationships between h…
Electron microscopic study on the larval and adult corpus allatum of Oncopeltus fasciatus dallas (insecta, heteroptera)
1973
1. The ultrastructure of the corpora allata of last larval instars and adults of Oncopeltus was studied. The unpaired gland undergoes submicroscopic alterations and shows signs of degradation in old animals. The organ is partly covered and penetrated by corpus cardiacum tissue. Axons with different types of neurosecretory granules form synaptoid contacts with the corpus allatum cells.
Quantitative analysis of "synaptic" ribbon profiles in the pineal complex of male and female Pirbright-White guinea pigs.
1990
Previous studies have pointed in the direction of sex differences as well as regional differences in the pineal gland of guinea pigs. In the present investigation these aspects were studied at the electron-microscopic level by quantitating different types of “synaptic” bodies, intrinsic to pinealocytes. The two major types of “synaptic” organelles, ribbons and spherules, did not exhibit regional or sex differences. “Synaptic” structures intermediate in appearance to ribbons and spherules were significantly larger in number in males in the distal region of the pineal gland, compared to females. As previous studies have shown that ribbon and spherule numbers undergo characteristic changes dep…