scholarly journals THE FINE STRUCTURE OF THE GASTRIC MUCOSA IN THE BAT

1963 ◽  
Vol 16 (3) ◽  
pp. 541-577 ◽  
Author(s):  
Susumu Ito ◽  
Robert J. Winchester
Keyword(s):  
Fine Structure ◽  
Gastric Mucosa ◽  
Secretory Granules ◽  
Cell Types ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Parietal Cells ◽  
Electron Microscopic ◽  
Gastric Glands ◽  
Mucous Neck Cells

A description of the cytology of the gastric mucosa is presented based upon an electron microscopic investigation of the bat stomach. The fine structure of the various cell types in this species is fundamentally similar to that of the corresponding cell types of other mammals, but the relative cell numbers and distribution are somewhat different. (a). The surface mucous cells are identified by their superficial location and by the character of their dense secretory granules. (b). The mucous neck cells are distinguished by a characteristically different appearance and distribution of their mucous granules, and by their varied shape and their location between parietal cells. (c). The parietal cells are very large and have unusually prominent secretory canaliculi and an extraordinary number of large mitochondria. (d). The chief cells are found at the base of the gastric glands and are similar in their fine structure to other zymogenic cells. They contain many large zymogen granules and have an extensively developed granular endoplasmic reticulum. The latter is sometimes aggregated in unusual, hexagonally packed straight tubules, each with twelve longitudinal rows of ribosomes uniformly spaced around its circumference and with the rows of ribosomes in precise register with those of adjoining tubules. (e). Argentaffin cells lodged between other cell types vary sufficiently in the structure of their mitochondria and the character of their specific granules to suggest that they are of more than one kind. The majority are at the base of the epithelium but some extend to the lumen and bear microvilli on their free surface.

Immunolocalization of anion exchanger AE2 and cation exchanger NHE-1 in distinct adjacent cells of gastric mucosa

1994 ◽  
Vol 266 (2) ◽  
pp. C559-C568 ◽  
Author(s):  
A. Stuart-Tilley ◽  
C. Sardet ◽  
J. Pouyssegur ◽  
M. A. Schwartz ◽  
D. Brown ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Parietal Cell ◽  
Anion Exchanger ◽  
Cell Types ◽  
Parietal Cells ◽  
Morphological Evidence ◽  
Mucous Cells ◽  
Gastric Glands ◽  
Basolateral Membranes ◽  
Mucous Neck Cells

The gastric mucosa secretes both protons and bicarbonate. The molecular identity of the H(+)-K(+)-ATPase, which mediates acid secretion, has long been known, but the other components of the secretory machinery and their cellular disposition are less well characterized. This study identifies and localizes in rat and rabbit gastric mucosa a chloride-bicarbonate exchanger protein and a Na(+)-H+ exchanger protein. The previously described band 3-related protein of the parietal cell has been identified by isoform-specific antibodies as anion exchanger (AE) 2 and localized to the basolateral membranes of the parietal cells. The Na(+)-H+ exchanger protein NHE-1 was located in the basolateral membranes of the mucous neck cells, interdigitated between the parietal cells of the gastric glands and in the basolateral membranes of the surface mucous cells. Neither transporter protein was abundantly expressed deep in the gland, where most of the pepsinogen cells reside. Carbonic anhydrase II (CA II) was expressed at higher abundance in the surface mucous cells and mucous neck cells, which expressed NHE-1, than in the parietal cells, which expressed AE2. The morphological evidence identified AE2 as a major parietal cell anion exchanger, whereas NHE-1 and CA II colocalized in mucous neck, chief, and surface mucous cells. We propose that all three of these cell types contribute to gastric bicarbonate secretion.

Ultrastructural Studies on an Unidentified Microorganism in Urine

1980 ◽  
Vol 38 ◽  
pp. 492-493
Author(s):  
C. N. Sun ◽  
P. N. Morgan ◽  
F. Herring ◽  
H. J. White
Keyword(s):  
Fine Structure ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Yeast Cells ◽  
Urine Specimen ◽  
Electron Microscopic ◽  
Gram Negative ◽  
Ultrastructural Studies ◽  
Transitional Forms ◽  
Urine Specimens

We recently studied the fine structure of unusual microorganisms in a urine specimen. To our knowledge, previous electron microscopic investigation of these microorganisms has never been done. The microorganisms were found in the sediments of two separate urine specimens obtained from a 55 year old patient. In these samples, there were yeast cells and two types of gram negative microorganisms; a typical rodlike, non-mobile bacterium, and a spheroid form with two projections. The latter organisms were varying sizes and moved by a typical serpent-like motility. The rod-like structures were approximately 0.4 - 1 μ in diameter and up to 8 μ in length. The spheroid structures, which stained homogeneously and were not spore-like in appearance, were approximately 6 μ in diameter. A few intermediate or transitional forms of various sizes and shapes were also found.

Observations on healing tissue: A combined light and electron microscopic investigation

1963 ◽  
Vol 246 (733) ◽  
pp. 305-325 ◽  
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Light Microscopy ◽  
Secretory Activity ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Foreign Body Giant Cell ◽  
Electron Microscopic ◽  
Adventitial Cells

1. The process of healing in the rabbit ear chamber has been investigated in detail by correlating light microscopy, mainly in vivo , and electron microscopy. 2. During healing new vessels are formed from existing vessels by a process of sprouting and anastomosis, with subsequent remodelling of the loops so formed. 3. The fundamental process in the formation of vessels by sprouting is the mitotic division of existing endothelium, during which it retains its characteristic properties. 4. Blood vessel sprouts are composed of strands of tightly apposed cells formed in continuity with the walls of existing vessels. The subsequent canalization of such strands takes place extra-cellularly by a series of events largely as described by Billroth (1856). 5. The endothelium of recently formed vessels has a fine structure which distinguishes it clearly from that of more mature vessels. Certain features of this structure are compatible with a secretory activity by the endothelium during the formation of new vessels. 6. Evidence was obtained that in the course of differentiation of recently formed vessels fibroblast-like cells are incorporated into vessel walls to become adventitial cells, and that adventitial cells may undergo conversion to vascular smooth muscle cells. 7. Lymphatic endothelium exhibits properties during regeneration that confirm the specificity of this form of endothelium. 8. Cells with the characteristic fine structure of fibroblasts were frequently found in mitosis. The fibroblasts in the regions of active fibrogenesis had a highly developed cisternal form of endoplasmic reticulum. Vesicles and corresponding caveolae identifiable in such fibroblasts may provide a communication between the endoplasmic reticulum and the sites of fibrogenesis at the external surfaces of the cells. 9. Cells sharing characteristic features of fine structure formed a series which grouped together the monocyte, macrophage and foreign body giant cell. 10. Highly fibrillary intracytoplasmic tracts were found in both fibroblasts and macrophages. These tracts were equated with the fibroglial fibres of light microscopy. 11. ‘ Clear spaces ’ in advance of the growing fringe of blood vessels were temporary structures lined by a pavement of mesothelium-like cells. 12. No evidence was found of the formation of primitive mesenchymal tissue during healing in the mammal.

scholarly journals CELLULAR SPECIALIZATION IN THE EXCRETORY EPITHELIA OF AN INSECT, Macrosteles fascifrons STÅL (HOMOPTERA)

1960 ◽  
Vol 8 (1) ◽  
pp. 103-133 ◽  
Author(s):  
David S. Smith ◽  
Virginia C. Littau
Keyword(s):  
Malpighian Tubule ◽  
Cell Types ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Malpighian Tubules ◽  
Apical Surface ◽  
Electron Microscopic ◽  
Distinct Cell ◽  
Protein Components ◽  
Cellular Specialization

An electron microscopic investigation of the Malpighian tubules of a leaf hopper, Macrosteles fascifrons, shows that these organs comprise three quite distinct cell types, and the structure of these and of the mid- and hindgut epithelial cells is described. In particular, a comparison is made between the organization of the basal and apical surfaces of cells in the Malpighian tubule and in the vertebrate kidney, and it is suggested that similarities between these excretory epithelia reflect functional parallels between them. While the midgut and one region of the Malpighian tubule bear a typical microvillar brush border, elsewhere in the tubule and in the hindgut the apical surface bears cytoplasmic leaflets or lamellae. The sole solid excretory material of these insects consists of the brochosomes, secreted by cells of one region of the Malpighian tubule. The structure, geometry, and development of these unusual bodies, apparently formed within specialized Golgi regions, has been investigated, and histochemical tests indicate that they contain lipid and protein components.

THE ULTRASTRUCTURE OF THE ACCESSORY SEX ORGANS OF THE MALE RAT

1973 ◽  
Vol 74 (3) ◽  
pp. 605-614 ◽  
Author(s):  
Erik Dahl ◽  
Kjell J. Tveter ◽  
Åsmund Kjaerheim
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Secretory Granules ◽  
Electron Microscopic Examination ◽  
Cell Types ◽  
Male Rat ◽  
Electron Microscopic ◽  
Genital Complex ◽  
Accessory Sex Organs ◽  
Complete Regeneration

ABSTRACT The present paper describes the fine structure of the accessory sex organs of the male rat as seen after stimulation with testosterone administered to castrated adults as well as infantile rats. Electron microscopic examination of the testosterone-treated castrated animals revealed an almost complete regeneration of the epithelial cells in all the organs, with a well developed Golgi area, a well developed rough endoplasmic reticulum and an increased number of secretory granules. The results obtained are discussed in relation to the biochemical data, and it is concluded that the various cell types of the accessory genital complex react in a fundamentally similar manner to the administration of testosterone.

Light and electron microscopic investigation of adenohypophyses of germfree, food-restricted, and germfree-food restricted aging, male lobund-wistar rats

1988 ◽  
Vol 46 ◽  
pp. 352-353
Author(s):  
G. Ilse ◽  
K. Kovacs ◽  
N. Ryan ◽  
T. Sano ◽  
L. Stefaneanu ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Aging Male ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Sprague Dawley Rats ◽  
Old Rats ◽  
Ad Libitum ◽  
Microscopic Findings

Germfree state and food restriction have been shown to increase life span and delay tumor occurrence in rats. We report here the histologic, immunocytochemical and electron microscopic findings of adenohypophyses of aging, male Lobund-Wistar rats raised at Lobund Laboratories. In our previous study, the morphologic changes in the adenohypophyses of old rats have been extensively investigated by histology, immunocytochemistry and electron microscopy. Lactotroph adenomas were frequent in Long-Evans and Sprague-Dawley rats, whereas gonadotroph adenomas were frequent in Sprague-Dawley and Wistar rats.Male Lobund-Wistar rats were divided into four groups: 1) conventional, which were raised under normal non-germfree environment and received food ad libitum; 2) germfree-food ad libitum; 3) conventional environment-food restricted and 4) germfree-food restricted. The adenohypophyses were removed from 6-month-, 18-month- and 30-month-old rats. For light microscopy, adenohypophyses were fixed in formalin and embedded in paraffin.

An Electron Microscopic Study of the Acute Effects of Hypothalamic Releasing Factors on the Anterior Pituitary Gland

1968 ◽  
Vol 26 ◽  
pp. 232-233
Author(s):  
P.W. Coates ◽  
E.A. Ashby ◽  
L. Krulich ◽  
A. Dhariwal ◽  
S. McCann
Keyword(s):  
Anterior Pituitary ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Thin Sections ◽  
Dense Membrane ◽  
Membrane Bound ◽  
Releasing Factors

The morphologic effects on somatotrophs of crude sheep hypothalamic extract prepared from stalk-median eminence were studied by electron microscopy in conjunction with concurrently run bioassays performed on the same tissue samples taken from young adult male Sherman rats.Groups were divided into uninjected controls and injected experimentals sacrificed at 5', 15', and 30' after injection. Half of each anterior pituitary was prepared for electron microscopic investigation, the other half for bioassay. Fixation using collidine buffered osmium tetroxide was followed by dehydration and embedment in Maraglas. Uranyl acetate and lead citrate were used as stains. Thin sections were examined in a Philips EM 200.Somatotrophs from uninjected controls appeared as described in the literature (Fig. 1). In addition to other components, these cells contained moderate numbers of spherical, electron-dense, membrane-bound granules approximately 350 millicrons in diameter.

Fine Structural Classification of Chromophobe Adenomas of the Human Pituitary Gland

1975 ◽  
Vol 33 ◽  
pp. 378-379
Author(s):  
K. Kovacs ◽  
E. Horvath
Keyword(s):  
Pituitary Adenomas ◽  
Secretory Activity ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Human Pituitary ◽  
Cytoplasmic Staining ◽  
Human Pituitary Gland ◽  
Microscopic Features

Chromophobe pituitary adenomas arise from adenohypophysial cells and fail to exhibit cytoplasmic staining with conventional acid or basic dyes by light microscopy. The aim of the present work was to study the electron microscopic features of these tumors, to separate them into distinct entities and to correlate their fine structural appearances with secretory activity.Among 48 surgically removed various pituitary adenomas 30 tumors were found which, based on the tinctorial characteristics of the cytoplasm, corresponded to chromophobe adenomas. For electron microscopic investigation pieces of these tumors were fixed in 2.5 per cent glutaraldehyde in Sorensen's buffer, post fixed in 1 per cent osmium tetroxide in Millonig's buffer, dehydrated in graded ethanol and embedded in Epon 812. Ultrathin sections were stained with uranyl acetate and lead citrate.By electron microscopy it was possible to separate chromophobe adenomas into 3 distinct entities: 1) adenomas consisting of sparsely granulated growth hormone cells (7 cases).

Temporal and spatial interrelationships of confronting cisternae to nuclear envelope

1992 ◽  
Vol 50 (1) ◽  
pp. 930-931
Author(s):  
John R. Palisano
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Tumor Cells ◽  
Hela Cells ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Serial Sections ◽  
Electron Microscopic ◽  
Fetal Rat ◽  
Temporal And Spatial

Although confronting cistemae (CC) have been observed in a variety of tumor cells and normal fetal rat, mouse, and human epithelial tissues, little is known about their origin or role in mitotic cells. While several investigators have suggested that CC arise from nuclear envelope (NE) folding back on itself during prophase, others have suggested that CC arise when fragments of NE pair with endoplasmic reticulum. An electron microscopic investigation of 0.25 um thick serial sections was undertaken to examine the origin of CC in HeLa cells.

Electron Microscopic investigation of crooke’s change in the pituitaries of patients with hypercorticism

1989 ◽  
Vol 47 ◽  
pp. 848-849
Author(s):  
E. Horvath ◽  
K. Kovacs ◽  
L. Stefaneanu ◽  
N. Losinski
Keyword(s):  
Nucleolar Organizer ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Ectopic Acth Syndrome ◽  
Nucleolar Organizer Regions ◽  
Electron Microscopic ◽  
Human Pituitary ◽  
Ectopic Acth ◽  
Crooke’S Hyalinization

Human pituitary corticotropins have unique morphologic markers: bundles of type-1 filaments, measuring approximately 70 A in width and representing cytokeratin. The extreme ring-like accumulation of type-1 filaments, known as Crooke's hyalinization, signals functional suppression of the corticotropins and occurs in endogenous and exogenous glucocorticoid excess, caused by ACTH-secreting pituitary adenoma, glucocorticoid secreting adrenocortical tumor, ectopic ACTH-syndrome and administration of pharmacologic doses of glucocorticoids. Cells of autonomous corticotroph adenomas usually do not show Crooke's hyalin change. A minority of these tumors, however, retains sensitivity to the negative feed-back effect of elevated blood glucocorticoid levels and display typical Crooke’s change.In the present study pituitary corticotropins in various phases of Crooke's hyalinization were investigated in patients with glucocorticoid excess of various origin, applying histology, immunocytochemistry, count of argyrophilic nucleolar organizer regions (AgNOR), and transmission electron microscopy.

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