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.

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.

Characterization of Electrophoretic Lipoprotein Fractions: Immunochemical and Electron Microscopic Studies

1972 ◽  
Vol 18 (6) ◽  
pp. 534-538
Author(s):  
Mario Werner ◽  
Albert L Jones
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Electrophoretic Pattern ◽  
Electron Microscopic ◽  
Lipoprotein Subfractions ◽  
New Techniques ◽  
Microscopic Studies ◽  
Insight Into

Abstract To improve the characterization of electrophoretic lipoprotein subfractions, we developed two new techniques for analyzing lipoproteins after electrophoresis on thin agarose layers. Overlay with antisera exactly localizes specific apoproteins without any distortion caused by antigen diffusion; electron microscopy of eluted fractions determines the varying particle-size distribution. Applied together, these methods can detect individual differences between hyperlipemic samples that are not immediately apparent in the electrophoretic pattern, and should provide valuable new insight into the classification of hyperlipoproteinemias.

scholarly journals Retrospective demonstration of endogenous peroxidase activity in plastic-embedded tissues conventionally prepared for electron microscopy.

1981 ◽  
Vol 29 (7) ◽  
pp. 874-876 ◽  
Author(s):  
M Del Cerro ◽  
J P Cogen ◽  
C Del Cerro
Keyword(s):  
Electron Microscopy ◽  
Peroxidase Activity ◽  
Pigment Epithelium ◽  
Sodium Ethoxide ◽  
Retinal Pigment ◽  
Cell Types ◽  
Uranyl Acetate ◽  
Microscopical Examination ◽  
Electron Microscopic ◽  
Endogenous Peroxidase

A procedure is described that permits retrospective demonstration of intracellular endogenous peroxidase activity in tissue conventionally prepared for electron microscopy, i.e., doubly fixed with aldehydes and osmium tetroxide, "stained" in block with uranyl acetate, and embedded in epoxy resins. Using sodium ethoxide, plastic was removed from 1 micrometer sections; subsequently, the sections were incubated for 20 min in diaminobenzidine solution (44 mg/100 ml) made in acetate-citric acid buffer, pH 5.6, with 0.01% hydrogen peroxide. After this treatment, the sections were rinsed, dehydrated, and mounted. Cell types known to have endogenous peroxidase activity (red blood cells, macrophages, and retinal pigment epithelium cells in our preparations) show positive granules in their cytoplasm--control sections were uniformly negative. This method, which could also be used prospectively, cytochemically demonstrates endogenous peroxidase activity upon optical microscopical examination of the treated tissues; correlative electron microscopic studies may be performed on the same tissue block, or even adjacent sections.

Organs of a Baikal seal affected by a morbillivirus

1990 ◽  
Vol 48 (3) ◽  
pp. 968-969
Author(s):  
O.I. Belykh ◽  
Ye.V. Likhoshway ◽  
Yu.V. Solodun ◽  
O.A. Goldberg ◽  
V.P. Kumarev
Keyword(s):  
Electron Microscopy ◽  
Measles Virus ◽  
Present Report ◽  
Protein A ◽  
Uranyl Acetate ◽  
Kidney Cells ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Liver And Kidney ◽  
Ultrathin Sections

The population of Baikal seals Phoca sibirica has been plagued in 1987-88 by an unknown disease. Oligonucleotide probing of nucleic acids isolated from tissues of ill and dead animals, as well as immunological evidence and clinical data suggested that seals were infected by a morbillivirus. Morbillivirus antigen has been vizualized in dead seal tissues by immunoelectron microscopy (preembedding technique).The present report gives outline of electron microscopic studies of the tissues of infected Baikal seals. Morbillivirus antigens were vizualized as clusters of gold spheres by postembedding technique with monoclonal antibodies against measles virus and protein A-colloid gold conjugates in nuclei and cytoplasm of liver and kidney cells. Some clusters were associated with virus-like particles having a diameter of 80-100 nm. Electron microscopy of ultrathin sections stained with uranyl acetate revealed nucleocapsides having length of up to 1400 nm, and a diameter of 13-17 nm, morphologically similar to measles and seals distemper virus.

scholarly journals EVIDENCE FOR CHANGES IN PROTEIN POLYSACCHARIDE ASSOCIATED WITH THE ONSET OF CALCIFICATION IN CARTILAGE

1968 ◽  
Vol 39 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Victor J. Matukas ◽  
George A. Krikos
Keyword(s):  
Electron Microscopy ◽  
Osmium Tetroxide ◽  
Marked Decrease ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Calcified Cartilage ◽  
The Matrix ◽  
Microscopic Studies ◽  
Matrix Components

Past work has suggested that protein polysaccharide may play a role in the calcification of cartilage. Recent electron microscopic studies on noncalcified cartilage have indicated that protein polysaccharide in cartilage matrix is represented by granules associated with collagen fibers. The present work has been designed for comparison of the matrix of noncalcified cartilage to that of calcified cartilage, with particular reference to these granules. Small blocks of tibia from 16-day embryos were fixed in cacodylate-buffered glutaraldehyde and postfixed in either phosphate- or Veronal-buffered osmium tetroxide. Special care was taken to maintain the pH above 7.0 at all times. For electron microscopy the tissues were dehydrated, embedded in Epon 812, sectioned, and stained with uranyl acetate or lead citrate. A marked decrease in the size of granules in the matrix of calcified cartilage compared to noncalcified cartilage was noted. Associated with the decrease in the size of granules was a condensation of matrix components and the presence of an amorphous electron-opaque material that was not seen in noncalcified areas. These results are interpreted to represent either a drop in concentration or a change in state of protein polysaccharide with the onset of calcification in cartilage.

Localization of immunolabels by electron microscopy and image averaging

1983 ◽  
Vol 41 ◽  
pp. 282-283
Author(s):  
J. Frank ◽  
P.-Y. Sizaret ◽  
A. Verschoor ◽  
J. Lamy
Keyword(s):  
Electron Microscopy ◽  
Single Particle ◽  
Attachment Site ◽  
Uranyl Acetate ◽  
Limulus Polyphemus ◽  
Resolution Limit ◽  
Electron Microscopic ◽  
Image Averaging ◽  
Top View ◽  
Better Than

The accuracy with which the attachment site of immunolabels bound to macromolecules may be localized in electron microscopic images can be considerably improved by using single particle averaging. The example studied in this work showed that the accuracy may be better than the resolution limit imposed by negative staining (∽2nm).The structure used for this demonstration was a halfmolecule of Limulus polyphemus (LP) hemocyanin, consisting of 24 subunits grouped into four hexamers. The top view of this structure was previously studied by image averaging and correspondence analysis. It was found to vary according to the flip or flop position of the molecule, and to the stain imbalance between diagonally opposed hexamers (“rocking effect”). These findings have recently been incorporated into a model of the full 8 × 6 molecule.LP hemocyanin contains eight different polypeptides, and antibodies specific for one, LP II, were used. Uranyl acetate was used as stain. A total of 58 molecule images (29 unlabelled, 29 labelled with antl-LPII Fab) showing the top view were digitized in the microdensitometer with a sampling distance of 50μ corresponding to 6.25nm.

Cytoplasmic Invaginations in Trophoblasts and Epithelial Cells of Rat

1971 ◽  
Vol 29 ◽  
pp. 524-525
Author(s):  
Iracema M. Baccarini
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Nuclear Inclusions ◽  
Mucous Cells ◽  
Electron Microscopic ◽  
Cervical Epithelium ◽  
Intact Membrane ◽  
Microscopic Studies ◽  
Abnormal Cells ◽  
Nuclear Features

Some morphological nuclear features (invaginations) in normal and abnormal cells have been described in several electron microscopic studies. They have been referred to by others as blebs, loops, pockets, sheets, bodies, nuclear inclusions and cytoplasmic invaginations. Identical appearing structures were found in cells of the uterine cervical epithelium, in trophoblasts of blastocysts and in trophoblasts of rat placenta.Methods. Uterine cervix (normal rats), rat placenta (9-10 days gestation) and blastocyst were placed in 3% glutarahdehyde for 3 hours. The tissue was washed in phosphate buffer for 24 hours, postfixed in 1%. buffered osmium tetroxide for 1-2 hours and embedded in epon araldite. Sections were double stained with uranyl acetate and lead citrate and viewed in E. M. Siemens 200.Observations. Nuclear invaginations were found in basal, parabasal and mucous cells of the cervix epithelium, in trophoblasts of blastocyst and in trophoblasts of placenta. An oval, round or elongated invagination contained heterogenously cytoplasm surrounded by a double intact membrane; usually several invaginations were found in the same nucleus.

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.

scholarly journals Preservation of alveolar type II pneumocyte lamellar bodies for electron microscopic studies.

1979 ◽  
Vol 27 (5) ◽  
pp. 989-996 ◽  
Author(s):  
A J Collet
Keyword(s):  
Uranyl Acetate ◽  
Alkaline Solutions ◽  
Alveolar Type ◽  
Morphological Aspect ◽  
Type Ii ◽  
Lamellar Bodies ◽  
Electron Microscopic ◽  
Type Ii Pneumocyte ◽  
Microscopic Studies ◽  
Freeze Etching

Simultaneous fixation with glutaraldehyde and osmium tetroxide, followed by an uranyl acetate (UA) treatment before dehydration and embedding (Hirsch and Fedorko 1968) ensures a very good preservation of lamellar bodies (LB's) as well as of the cellular membranes in type II pneumocyte. The uranyl acetate treatment appeared to be the most efficient step of the procedure. The morphological aspect of lamellar bodies after such a preparation was similar to that observed after freeze-etching of lipid retaining methods. Moreover, the Hirsch-Fedorko procedure is very simple and can easily be used for routine ultrastructural and radioautographic studies. On the other hand, it appeared that the uranyl acetate phospholipid "complex" is very sensitive to the pH of chemical solutions used after sectioning. The "complex" is variously dissolved by alkaline solutions, photographic developers or stains. The best preservation of ultrastructure was obtained with neutral or acidic developers and acidic stains.

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.

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