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.

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.

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.

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.

scholarly journals Karyometric and electron microscopic studies of dark and light cells of the adrenal cortex in mammals

2018 ◽  
Vol 7 (3) ◽  
pp. 61-67 ◽  
Author(s):  
A. G. Ul'yanov ◽  
P. M. Torgun
Keyword(s):  
Electron Microscopy ◽  
Adrenal Cortex ◽  
Lipid Droplets ◽  
Adrenal Glands ◽  
Ovis Aries ◽  
Secretory Cells ◽  
Electron Microscopic ◽  
Dark Cells ◽  
Microscopic Studies ◽  
Light Cells

The purpose of this study is a comparative study of dark and light cells of cortical parenchyma of the adrenal glands in mammals using light and electron microscopy. Material and methods. Cariometric and electron microscopic studies of the adrenal glands of 9 mammalian species have been carried out: Vulpes vulpes (fox), Vulpes lagopus (arctic fox), Canis familiaris (dog), Мartes zibellina (sable), Mustela vison (mink), Enhydra lutris (sea ape); Castor fiber (river beaver); Callorhinus ursinus (fur seal); Ovis aries (sheep). Serial paraffin sections were stained with hematoxylin and eosin, iron hematoxylin, Heidenheim azan, the PAS-reaction was used, the color of the trichrome-PAS and the tetrachromium-PAS. RNA was detected by the reaction of Brashe and gallocyanin by Einarsson. For the detection of lipids, frozen sections were stained with Sudan III + IV, Black Sudan. The number of dark and light cells in the cortex of the adrenal mink in different seasons was determined. On electron micrographs, the amount of lipid droplets and mitochondria in the fascicle of the adrenal cortex was counted. Results. In the cortex of the adrenal glands of mammals, dark and light cells are present. Dark cells, as far as accumulation of sudanophilic substances are converted into light cells, which with further accumulation of lipids undergo destructive changes. Also found are the dark dying cells of the adrenal cortex, characterized by densification of the cytoplasm, pycnosis of nuclei, accumulation of yellow-brown pigment. Dark cells have larger nuclei, give more intense reaction to RNA and ketosteroids and are more active secretory cells compared to light adrenocorticocytes. Electron microscopy in dark cells reveals a large number of mitochondria and a significant amount of lipid droplets are present. Light cells contain many lipid inclusions and few mitochondria.

Electron Microscopic Studies of Microprojections on Aging Cells and Tissues

1980 ◽  
Vol 38 ◽  
pp. 784-785
Author(s):  
J. E. Johnson
Keyword(s):  
Human Fibroblasts ◽  
Cell Types ◽  
Cell Strain ◽  
Population Doubling ◽  
Electron Microscopic ◽  
Microscopic Studies

Microprojections, and specifically, microvilli, are present on many cell types. The cells which have them are often involved in either secretion or absorption In 1975 Bowman and Daniel1 reported that increased numbers of microvilli were present on WI-38 human fibroblasts in vitro at higher population doubling levels. A new cell strain, IMR-90 was recently developed to supplement the depleting supplies of WI-38. We wished to determine if increased numbers of microvilli were to be found on aging cells in general and began by examining the IMR-90. Indeed, this cell strain was also found to show higher indices with increased population doubling levels2 .

Effect of Steroids on Uterotubal Junction: An Ultrastructural and Cytochemical Study

1972 ◽  
Vol 30 ◽  
pp. 14-15
Author(s):  
R. K. Nayak ◽  
A. S. H. Wu
Keyword(s):  
Cell Types ◽  
Ciliated Cells ◽  
Electron Microscopic ◽  
Hormonal Stimulation ◽  
Cytochemical Study ◽  
Experimental Procedure ◽  
Exogenous Estrogen ◽  
Microscopic Studies ◽  
Tubal Lumen ◽  
Adequate Data

The morphology, and histology of mammalian uterotubal junction have been extensively studied. Only a limited number of electron microscopic studies on this organ have been published. Furthermore, adequate data on the fine structure and ultracytochemistry of this organ are not available. Investigation of this subject, therefore, was initiated on the tubal junction of the intact prepubertal and ovariectomized rabbit to delineate changes induced by near physiologic levels of exogenous estrogen and progesterone. Experimental procedure is the same as reported previously.Two distinctive cell types, namely ciliated and secretory, are observed in the epithelia. The most obvious change after hormonal stimulation is the regeneration of cilia and basal bodies in the ciliated cells and the frequent extrusion of mucin-like granules into the tubal lumen (Figs. 1,3,4). Polysomal associations and fibrous granules are frequently seen in the cytoplasm of ciliated cells.

Pathogenesis of Acute Toxoplasmosis in Specific-Pathogen-Free Cats

1981 ◽  
Vol 18 (6) ◽  
pp. 786-803 ◽  
Author(s):  
G. A. Parker ◽  
J. M. Langloss ◽  
J. P. Dubey ◽  
E. A. Hoover
Keyword(s):  
Mononuclear Cells ◽  
Cell Types ◽  
Lymphoid Hyperplasia ◽  
Type I ◽  
Specific Pathogen Free ◽  
Mesenteric Lymph Nodes ◽  
Electron Microscopic ◽  
Associated Lesions ◽  
Specific Pathogen ◽  
Microscopic Studies

Systemic toxoplasmosis was produced in specific-pathogen-free cats by intravenous inoculation with Toxoplasma gondii tachyzoites. Infectious organisms were recovered from all tissues studied, but the number of organisms recovered from liver, lungs and spleen was 10-fold to 10,000-fold higher than from heart and brain. The occurrence and severity of Toxoplasma-induced lesions correlated with the number of infectious organisms recovered from the various tissues. In nonlymphoid tissues, the Toxoplasma-associated lesions consisted of multifocal necrosis, usually with demonstrable organisms. Lesions in the spleen and mesenteric lymph nodes consisted of reticuloendothelial and lymphoid hyperplasia, with few demonstrable organisms. Pneumonitis was severe and sometimes fatal in the early stages of systemic toxoplasmosis. Light- and electron-microscopic studies showed that the earliest lung lesions were randomly distributed infiltrates of neutrophils, eosinophils, and mononuclear cells into alveolar walls. Later lesions were diffuse alveolar necrosis, pneumocytic hyperplasia, and extensive fibrinocellular exudates in alveoli. Tachyzoites were present in cytoplasmic vacuoles of fibroblasts, macrophages, type I and II pneumocytes, bronchiolar epithelial cells, bronchiolar smooth muscle cells, endothelial cells, neutrophils, eosinophils, and circulating monocytes. Replication of organisms was found in all parasitized cell types except neutrophils and eosinophils.

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