scholarly journals THE FINE STRUCTURE OF BONE CELLS

1961 ◽  
Vol 11 (3) ◽  
pp. 627-649 ◽  
Author(s):  
H. Robert Dudley ◽  
David Spiro
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Bone Cells ◽  
Amorphous Material ◽  
Granular Endoplasmic Reticulum ◽  
Lamellar Bone ◽  
Cell Surfaces ◽  
Progressive Reduction ◽  
Electron Microscopic ◽  
Cytoplasmic Processes

An electron microscopic study of Araldite-embedded, undecalcified human woven and chick lamellar bone is presented. The fine structure of the cells of bone in their normal milieu is described. Active osteoblasts possess abundant granular endoplasmic reticulum, numerous small vesicles, and a few secretion droplets. Their long cytoplasmic processes penetrate the osteoid. The transition of osteoblasts into osteoid osteocytes and then into osteocytes is traced and found to involve a progressive reduction of cytoplasmic organelles. Adjoining the osteocytes and their processes is a layer of amorphous material which is interposed between the cell surfaces and the bone walls of their respective cavities. Osteoclasts contain numerous non-membrane-associated ribosomes, abundant mitochondria, and little granular endoplasmic reticulum, thus differing markedly from other bone cells. The brush border is a complex of cytoplasmic processes adjacent to a resorption zone in bone. No unmineralized collagen is seen at resorption sites and it appears that collagen is removed before or at the time of mineral solution. All bone surfaces are covered by cells, some of which lack distinctive qualities and are designated endosteal lining cells. The structure of osteoid, bone, and early mineralization sites is illustrated and discussed.

The fine structure of the ookinete of Parahaemoproteus velans (= Haemoproteus velans Coatney and Roudabush) (Haemosporidia: Haemoproteidae)

1972 ◽  
Vol 50 (5) ◽  
pp. 477-480 ◽  
Author(s):  
Sherwin S. Desser
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Granular Endoplasmic Reticulum ◽  
Central Nucleus ◽  
Apical Region ◽  
Cylindrical Structures ◽  
Inner Surface

The ookinete of Parahaemoproteus velans is bounded externally by a trilaminar membrane, beneath which lies a fibrillar zone. Below this zone and forming the inner surface of the pellicle is a second, dense, membranelike layer. The specialized apical region of the ookinete is modified into a thickened "caplike" structure. The inner layer of the pellicle in this region is thickened and wavy in appearance. In a sub-pellicular space in the cap region lie about 27 elongate cylindrical structures, and beneath these about 50 microtubules ring the cytoplasm. Numerous dense spherical bodies are located in the anterior cytoplasm of the parasite. A large, more or less central nucleus, often containing microtubular elements, lies in a cytoplasm richly endowed with granular endoplasmic reticulum. Two or more areas containing a "crystalloid" material lie anterior and posterior to the nucleus.

An Electron Microscopic Study of the Human Gastric Epithelia with Special Reference to the Cardinal Morphological Changes of the Chief Cells Induced by Insulin Stimulus

1972 ◽  
Vol 30 ◽  
pp. 344-345
Author(s):  
Hiroshi Saito ◽  
Goro Asano ◽  
Kaoru Aihara ◽  
Katsunari Fukushi ◽  
Minoru Yoshida ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Morphological Changes ◽  
Regular Insulin ◽  
Endoscopic Biopsy ◽  
Granular Endoplasmic Reticulum ◽  
Ultrastructural Changes ◽  
Electron Microscopic ◽  
Chief Cells ◽  
Microscopic Studies ◽  
The One

This short communication is dealt with the ultrastructural changes of the chief cells in insulin stimulus in chronic gastritic condition. The bio gastro-endoscopic biopsy was obtained and pepsin activity of the gastric juice was measured in respective cases. Regular insulin of 0.15U/kg was administrated intra-muscularly and in pre-administration of insulin, 10 minutes, 20 minutes and 30 minutes after administration, biopsied specimens were subjected for electron microscopic studies.In the pre-treated chief cells, extensive development of the cysternal structures of the granular endoplasmic reticulum in basal aspect of the cytoplasm and spherical or oval shaped, light homogeneous zymogen granules in supranuclear region and especially apical aspect of the cytoplasm were featured. Moreover, other type of the chief cells as the one characterized by their fragmented and saccular dilated granular endoplasmic reticulum in basal aspect of the cytoplasm, also exist.

The fine structure of the developing macrogamete of Eimeria maxima

Parasitology ◽  
1979 ◽  
Vol 79 (2) ◽  
pp. 259-265 ◽  
Author(s):  
R. M. Pittilo ◽  
S. J. Ball
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Parasitophorous Vacuole ◽  
The Other ◽  
Granular Endoplasmic Reticulum ◽  
Type I ◽  
Type Ii ◽  
Eimeria Maxima ◽  
Lipid Inclusions

SUMMARYThe fine structure of the developing macrogamete of Eimeria maxima was studied from chicks killed at intervals from 138 to 147 h after inoculation. The macrogamete developed within a parasitophorous vacuole. Lying within this vacuole and extending for some distance around the periphery of the macrogamete were intravacuolar tubules, grouped in certain areas, and in some cases they were seen to make direct connexions with the cytoplasm of the parasite. During development, electron-pale vesicles were pinched off externally from the surface of the macrogamete. There appeared to be 2 forms of wall-forming bodies of the Type I during development, one form being less osmiophilic than the other. Other organelles present, such as wall-forming bodies of Type II, granular endoplasmic reticulum, mitochondria, canaliculi, lipid inclusions and intravacuolar folds, were similar in structure to those of other Eimeria species.

Electron Microscopic Characterization of Insect Hemocytes

1968 ◽  
Vol 26 ◽  
pp. 68-69 ◽  
Author(s):  
Gertraude Wittig
Keyword(s):  
Endoplasmic Reticulum ◽  
Amorphous Material ◽  
Cell Type ◽  
Electron Microscopic ◽  
Ultrathin Sections ◽  
The Subject ◽  
Insect Hemocytes ◽  
Spherical Cells ◽  
Army Worm

The fine structure of insect hemocytes has been the subject of very few investigations. In particular, the hemocytes of Lepidoptera have received almost no attention. The study presented here was carried out on the armyworm, Pseudaletia unipuncta. Hemocytes of the larva were fixed 2 to 4 days after molt to the sixth instar and studied in ultrathin sections.Microplasmatocytes (Fig. 1) were the most important phagocytes of army-worm hemolymph. They were relatively small, spherical cells with a small, round or lobed nucleus. Distensions of the perinuclear cisterna (p) were frequent and sometimes continuous with the rough endoplasmic reticulum (e). The latter formed greatly distended cisternae which almost filled the whole cytoplasm. The cisternae contained an amorphous material which appeared to be condensed in certain sacs (at e). Mitochondria (m) were rare, and they had tubular cristae. Up to four Golgi complexes (g) were identified in a microplasmatocyte section. Structured granules (sg) were specific for this cell type. Microfibrils (f) traversed the whole cytoplasm but were most frequent around the nucleus (N) and under the cell membrane.

Differentiation of Neurosensory Cells in Hydra

1969 ◽  
Vol 5 (3) ◽  
pp. 699-726
Author(s):  
LOWELL E. DAVIS
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Basal Body ◽  
Neurosecretory Cells ◽  
Nerve Cells ◽  
Granular Endoplasmic Reticulum ◽  
Structural Variations ◽  
Intercellular Bridges ◽  
Undifferentiated Cells

The differentiation of neurosensory cells in Hydra has been studied at the level of the electron microscope. These cells arise from interstitial cells (undifferentiated cells) and not from pre-existing nerve cells. Furthermore, there is no evidence to suggest that neurosensory cells represent a stage in the development of other nerve cells, i.e. ganglionic and neurosecretory cells. Major cytoplasmic changes in fine structure during differentiation include development of a cilium and associated structures (basal body, basal plate, rootlets), development of microtubules and at least two neurites, increase in Golgi lamellae and formation of dense droplets typical of neurosecretory droplets, structural variations in mitochondria and a decrease in the number of ribosomes. Granular endoplasmic reticulum is characteristically poorly developed in all stages of differentiation, including the mature neurosensory cell. Nuclear and nucleolar changes also occur during differentiation but these are less dramatic than the cytoplasmic events. The possibility of neurosensory cells being bi- or multiciliated and the presence of intercellular bridges between these cells are considered. The function of neurosensory cells is discussed briefly in relation to the function of the cilium and neurosecretory droplets.

The fine structure of Leucocytozoon simondi. V. The oocyst

1972 ◽  
Vol 50 (6) ◽  
pp. 707-711 ◽  
Author(s):  
Sherwin S. Desser
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Basal Lamina ◽  
Central Core ◽  
Granular Endoplasmic Reticulum ◽  
Midgut Epithelium ◽  
Stage Of Development ◽  
Peripheral Cytoplasm

Following penetration through the midgut epithelium of Simulium rugglesi, ookinetes of Leucocytezoon simondi round up beneath the basal lamina and transform into young oocysts. These spherical, walled structures contain a large central core of crystalloid material. Dividing nuclei are seen in the peripheral cytoplasm, which is characterized by several concentric layers of granular endoplasmic reticulum. In a succeeding stage of development the trilaminar plasma membrane appears intermittently doubled, and bud-like outgrowths occur in these thickened areas. At this stage the crystalloid material is dispersed throughout the cytoplasm. A nucleus, an elongate mitochondrion, and some crystalloid material move into each forming sporozoite, which continues to grow at the expense of the residual cytoplasm.

Insect frontal ganglion: fine structure of its neurosecretory cells in diapause and non-diapause larvae of Diatraea grandiosella

1975 ◽  
Vol 53 (8) ◽  
pp. 1093-1100 ◽  
Author(s):  
C.-M. Yin ◽  
G. M. Chippendale
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Neurosecretory Cells ◽  
Granular Endoplasmic Reticulum ◽  
Diatraea Grandiosella ◽  
Corn Borer ◽  
Golgi Bodies ◽  
Juvenile Hormone Mimic ◽  
Frontal Ganglion ◽  
Southwestern Corn Borer

The fine structure of the neurosecretory (NS) cells of the frontal ganglion (FG) of diapause and non-diapause mature larvae of the southwestern corn borer, Diatraea grandiosella, was compared. Two large (15- to 20-μm diam) NS cells are typically found in each FG. Their cytoplasm stained deeply purple with paraldehyde fuchsin and contained granules 1500–2500 Å in diameter. The granules in the NS cells of non-diapause larvae were often associated with Golgi bodies whereas those of the diapause larvae were associated with dilated cisternae of the granular endoplasmic reticulum. Fewer Golgi bodies were observed in sections of NS cells of the FG of diapause larvae than in those of non-diapause larvae. Sections prepared from diapause larvae obtained conventionally by exposure to low temperatures, and experimentally by treatment with a juvenile hormone mimic, gave similar results.Our findings show that granules accumulate in the perikaryon of the NS cells of the FG of diapause larvae and suggest that the granular endoplasmic reticulum is involved in their formation. The shutdown of the transport of these NS granules from the FG appears to be a factor in some yet to be determined phase of the neuroendocrine regulation of diapause.

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 AUTOPHAGIC VACUOLES PRODUCED IN VITRO

1968 ◽  
Vol 38 (2) ◽  
pp. 392-402 ◽  
Author(s):  
Martha E. Fedorko ◽  
James G. Hirsch ◽  
Zanvil A. Cohn
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Amorphous Material ◽  
Continuous Phase ◽  
Electron Microscopic ◽  
Autophagic Vacuoles ◽  
Golgi Region ◽  
Microscopic Studies ◽  
Initial Action

Continuous phase-contrast observations have been made on macrophages following exposure to chloroquine. The initial abnormality is the appearance in the Golgi region of small vacuoles with an intermediate density between that of pinosomes and granules. Over the course of 1–2 hr these vacuoles grow larger and accumulate amorphous material or lipid. Pinosomes or granules frequently fuse with the toxic vacuoles. Chloroquine derivatives can be seen by fluorescence microscopy; the drug is rapidly taken up by macrophages and localized in small foci in the Golgi region. Chloroquine continues to produce vacuoles when pinocytosis is suppressed. Electron microscopic studies of chloroquine effects on macrophages preincubated with colloidal gold to label predominately pinosomes or granules suggest that toxic vacuoles can arise from unlabeled organelles. Later vacuoles regularly acquire gold label, apparently by fusion, from both granules and pinosomes. L cells also develop autophagic vacuoles after exposure to chloroquine. Smooth endoplasmic reticulum apparently is involved early in the autophagic process in these cells. Information now available suggests an initial action of chloroquine on Golgi or smooth endoplasmic reticulum vesicles, and on granules, with alterations in their membranes leading to fusion with one another and with pinosomes.

The structure and development of the macrogamete and oocyst of Eimeria acervulina

Parasitology ◽  
1971 ◽  
Vol 62 (1) ◽  
pp. 31-34 ◽  
Author(s):  
D. L. Lee ◽  
B. J. Millard
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Technical Assistance ◽  
Granular Endoplasmic Reticulum ◽  
Type Ii ◽  
Oocyst Wall ◽  
Eimeria Acervulina ◽  
Early Stages

The fine structure of the macrogametocyte, macrogamete and the early stages in the formation of the oocyst wall of Eimeria acervulina have been described and compared with other species of Eimeria. It has been shown that type II wall-forming bodies are formed in cisternae of the granular endoplasmic reticulum in association with Golgi complexes. The developing oocyst has been shown to be enclosed by three membranes: the outermost is the original membrane of the merozoite and macrogametocyte; the second membrane appears when the wall-forming bodies are appearing in the cytoplasm of the macrogametocyte and the innermost membrane appears after fertilization. The wall-forming bodies discharge their contents between the innermost membrane and the middle membrane.We wish to thank Mr P. L. Long for much valuable discussion, Mrs B. Fisher for technical assistance and Mr B. Carter for assistance with the photography.

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