Correlative transmission and high-resolution scanning electron microscopic studies on pituitary cells

1990 ◽  
Vol 48 (3) ◽  
pp. 20-21
Author(s):  
S. Tai
Keyword(s):  
Cell Types ◽  
Depth Of Field ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Microscopic Studies ◽  
Structure And Activity ◽  
Intracellular Structure

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.

Scanning Electron Microscopic study on chicken pituitary cells

1989 ◽  
Vol 47 ◽  
pp. 972-973
Author(s):  
S. Tai ◽  
C. Velasquez
Keyword(s):  
Cell Types ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Scanning Electron Microscopic Study ◽  
Secretion Granules ◽  
Pituitary Glands

The cytology and histology of the vertebrate pituitary glands have been studied extensively under light microscopy and transmission electron microscopy. These informations form the basis for the generally accepted concept that the specific cell types synthesize, store and release their particular hormones. These hormonal products are stored in membrane-bound secretion granules in the cytoplasm.Tanaka developed the 0 smium-DMS 0-0 smium (ODO) method which can remove the excess cytoplasmic matrices from the frozen-fractured surface of pre-fixed cells and revealed intracellular structures of many kind s of cells from liver, retina, etc. In this work, we have used the ODO method and Field Emission SEM to obtain 3-dimensional images of the fine structure of pituitary cells, as a new approach to have a better idea about the intracellular organization of the hormone secretory cells .Chicken pituitary glands were fixed in 0.5% glutaraldehyde in 0.2M phosphate buffer(pH=7.2) for ½ h; rinsed with the same buffer; postfixed in 0.5% OsO4 for another ½h. After been rinsed throughly, specimens were passed through 25% and 50% dimethyl sulfoxide(DMSO) solution for 30 minutes each.

Dendritic cells of the human epidermis: immuno-electron microscopic studies of la antigen reactivity

1978 ◽  
Vol 36 (2) ◽  
pp. 644-645
Author(s):  
G. Rowden ◽  
M. G. Lewis ◽  
T. M. Phillips
Keyword(s):  
Dendritic Cells ◽  
Langerhans Cells ◽  
Cell Types ◽  
Cell Type ◽  
Electron Microscopic ◽  
La Antigen ◽  
Microscopic Studies ◽  
A Cell ◽  
C3 Receptors ◽  
Antigen Reactivity

Langerhans cells of mammalian stratified squamous epithelial have proven to be an enigma since their discovery in 1868. These dendritic suprabasal cells have been considered as related to melanocytes either as effete cells, or as post divisional products. Although grafting experiments seemed to demonstrate the independence of the cell types, much confusion still exists. The presence in the epidermis of a cell type with morphological features seemingly shared by melanocytes and Langerhans cells has been especially troublesome. This so called "indeterminate", or " -dendritic cell" lacks both Langerhans cells granules and melanosomes, yet it is clearly not a keratinocyte. Suggestions have been made that it is related to either Langerhans cells or melanocyte. Recent studies have unequivocally demonstrated that Langerhans cells are independent cells with immune function. They display Fc and C3 receptors on their surface as well as la (immune region associated) antigens.

scholarly journals Paraganglioma of the Filum Terminale

1978 ◽  
Vol 5 (2) ◽  
pp. 257-260 ◽  
Author(s):  
Réal Lagacé ◽  
Claude Delage ◽  
François Gagné
Keyword(s):  
Clinical Data ◽  
Cell Types ◽  
Vascular Network ◽  
Filum Terminale ◽  
Neurosecretory Granules ◽  
Electron Microscopic ◽  
Dark Cells ◽  
Microscopic Studies ◽  
Glomus Coccygeum

SUMMARY:An unusual tumor arising in the filum terminale is described. The clinical data revealed an extensive and slowly growing lesion. The histologic picture was characterized by a proliferation of lobules and sheets of regular cells within a rich vascular network. Electron microscopic studies showed light and dark cells with sustentacular extensions. Typical neurosecretory granules were obsen'ed in both cell types, establishing the diagnosis of para-ganglioma. The glomus coccygeum could be the site of this tumor.

Zymogen Secreting Cells in the Hepatopancreatic Duct of Pagurus Bernhardus (Linnaeus, 1758) and Clibanarius Longitarsus (De Haan, 1849) (Anomura)

Crustaceana ◽  
1995 ◽  
Vol 68 (5) ◽  
pp. 616-628
Author(s):  
C. Manjulatha ◽  
D. Erri Babu
Keyword(s):  
Connective Tissue ◽  
Secretory Activity ◽  
Secretory Cells ◽  
Main Duct ◽  
Zymogen Granules ◽  
Electron Microscopic ◽  
Food Material ◽  
Acidic Polysaccharide ◽  
Microscopic Studies ◽  
Pagurus Bernhardus

AbstractHistological and histochemical observations reveal that there are two clusters of acidic polysaccharide secreting glands at the opening of the mouth into the oesophagus in Pagurus bernhardus and Clibanarius longitarsus. Below these there are structurally similar glands in the connective tissue of the oesophagus. The epithelial cells lining the hepatopancreatic main duct show secretory activity and they secrete acidophilic granular secretions, which are chemically similar to vertebrate pancreatic zymogen granules. Electron microscopic studies reveal the presence of secretory cells in the hepatopancreatic duct and the synthesis of zymogens within these cells. The time of release of these granular secretions synchronizes with the release of the food material into the midgut.

Problems in Myogenesis Terminology in Electron Microscopy

1967 ◽  
Vol 25 ◽  
pp. 38-39
Author(s):  
P.E. Conen ◽  
J.U. Balis ◽  
C.D. Bell
Keyword(s):  
Electron Microscopy ◽  
Cell Types ◽  
Uranyl Acetate ◽  
Electron Microscopic ◽  
Accurate Identification ◽  
Microscopic Studies ◽  
A Cell ◽  
Lead Hydroxide ◽  
Developing Muscle

Myogenesis in man was studied using muscle from 19 fetuses of 8 to 16 weeks gestation which were processed with standard osmium-Epon or glutaraldehyde-osmium-Epon schedules and sections were stained in uranyl acetate and/or lead hydroxide. Particular emphasis was given during this study to presence of basement membrane and myofilaments as additional aids in classification of cell types present in developing muscle.Electron microscopy permits accurate identification of fibroblasts and early cells of muscle series and has been used in studies of myogenesis in chick, and rat. Light microscopy definitions for premyoblasts and myoblasts, and for myocytes at the myotube and muscle fiber stages of development are difficult to apply to electron microscopic studies without modification. For example the term myoblast was used differently by Tello, Katznelson and Boyd to designate a cell destined to become muscle but not recognizable as a muscle cell.

Comparative ultrastructure of methanogenic bacteria

1975 ◽  
Vol 21 (2) ◽  
pp. 121-129 ◽  
Author(s):  
J. G. Zeikus ◽  
V. G. Bowen
Keyword(s):  
Morphological Characteristics ◽  
Cell Types ◽  
Methanogenic Bacteria ◽  
Diverse Group ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Intracytoplasmic Membranes ◽  
Microscopic Studies ◽  
Different Cell Types ◽  
Comparative Ultrastructure

Electron-microscopic studies using thin sections revealed that methane-producing bacteria were an ultrastructurally diverse group. Fine structure and morphological characteristics separated these bacteria into four discrete cell types. Methanogenic bacteria displayed a gram-positive cell wall that varied considerably among different cell types. Differences in granular inclusions, reserve materials, and intracytoplasmic membranes were observed. Unique ultrastructural features were not shared by all methanogenic species studied.

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