scholarly journals ETUDE AU MICROSCOPE ELECTRONIQUE DES TRANSFORMATIONS NUCLEAIRES DE E. COLI K12 S ET K12 S (λ26) APRES IRRADIATION AUX RAYONS ULTRAVIOLETS ET AUX RAYONS X

1960 ◽  
Vol 8 (2) ◽  
pp. 399-412 ◽  
Author(s):  
Antoinette Ryter
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
X Rays ◽  
Serial Sections ◽  
High Concentration ◽  
E Coli ◽  
Lysogenic Strain ◽  
Fragmented Nucleus ◽  
Ultrathin Sections ◽  
Condensation Effect

Nuclear transformations induced in E. coli K12S and K12S(λ26) by ultraviolet radiations and x-rays have been studied with ultrathin sections in the electron microscope. The nucleoplasm keeps its normal aspect during "fragmentation" and during "condensation" of the nucleus into the "vesicular" form. Serial sections show that the "fragmented" nucleus consists in reality of only one very tortuous vacuole. No difference either in the shape or in the fine structure of the nucleus could be observed between the lysogenic strain and the non-lysogenic strain. A high concentration of NaCl has a "condensation" effect on the fragmented nuclei and decreases the induction rate.

scholarly journals FINE STRUCTURE OF THE LARVAL ANURAN EPIDERMIS, WITH SPECIAL REFERENCE TO THE FIGURES OF EBERTH

1961 ◽  
Vol 10 (3) ◽  
pp. 425-435 ◽  
Author(s):  
George B. Chapman ◽  
Alden B. Dawson
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Free Surface ◽  
Electron Microscope ◽  
Fibrous Material ◽  
Distal Region ◽  
Epidermal Layer ◽  
Basal Plasma Membrane ◽  
Basal Plasma ◽  
Ultrathin Sections

Small pieces of skin from 8 cm long Rana clamitans larvae were fixed in OsO4, washed, dehydrated, and embedded in a methacrylate mixture. Ultrathin sections were cut on a Porter-Blum ultramicrotome and were examined in an RCA electron microscope, type EMU 2D. The sections showed that aggregates of fibrous material in the cells of the inner layer of epidermal cells are identical in disposition and size with the classical figures of Eberth. It is conclusively shown that these figures do not arise from an aggregation of mitochondrial filaments. The tendency of the fibrils to concentrate on attachment points, or thickenings of the basal plasma membrane, is noted. It is also observed that numerous mitochondria are located in the distal region of the cells of the outer layer of epidermis in association with the secretory vacuoles. Microvilli are seen occasionally on the free surface of the skin. Cisternae are found only in the cells of the outer epidermal layer, while vesicular endoplasmic reticulum is found in the cells of both epidermal layers.

scholarly journals The Fine Structure of the Retina Studied with the Electron Microscope

1959 ◽  
Vol 6 (2) ◽  
pp. 225-230 ◽  
Author(s):  
Kiyoteru Tokuyasu ◽  
Eichi Yamada
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Electron Microscope ◽  
Outer Segment ◽  
Distal Region ◽  
Serial Sections ◽  
Tubular Structures ◽  
Detailed Structure ◽  
Subsequent Time ◽  
Retinal Rods

The morphogenesis of the outer segments of retinal rods was studied mainly in the kitten before the opening of the eye, and the probable sequence of the morphogenetic stages is deduced. Since the development of retinal rods is not synchronous, the deductions were based on observations of many single and serial sections. One centriole extends ciliary tubules of about 0.5 µ long, in the growing primitive cilium. Beyond this length, each ciliary tubule becomes a row of small vesicles (called "ciliary vesicles" in this paper), which penetrate into the distal region of the cilium. Where the ciliary vesicles establish contact with the plasma membrane of the distal region of the cilium, more or less deep infoldings of the plasma membrane are observed. In the distal region can be seen rows of tubular or vesicular structures. A few of these membranous structures are continuous with the bottoms of the infoldings. At the following stage, the infoldings disappear and the ciliary vesicles lose contact with the distal plasma membrane. Nonetheless, the formation of the tubular structures continues in the distal region of the primitive outer segment. The tubular structures appear to be transformed into the primitive rod sacs by sidewise enlargement. At a subsequent time, presumably, these primitive rod sacs flatten and are rearranged into a position perpendicular to the long axis of the outer segment. The detailed structure of the basal body of the connecting cilium was also studied by means of serial sections.

scholarly journals THE FINE STRUCTURE OF CEROID IN HUMAN ATHEROMA

1967 ◽  
Vol 15 (12) ◽  
pp. 732-736 ◽  
Author(s):  
FERENC GYÖRKEY ◽  
TETSUO SHIMAMURA ◽  
ROBERT M. O'NEAL
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lamellar Structure ◽  
Periodic Acid ◽  
Periodic Acid Schiff ◽  
Histochemical Tests ◽  
Ultrathin Sections ◽  
Human Atheroma ◽  
Oil Red O ◽  
Electron Lucent

Ceroid in human atherosclerotic aorta was identified with histochemical tests (acid-fast, oil red O and periodic acid-Schiff techniques) applied to Epon-Araldite- and methacrylate-embedded tissues from which immediately adjacent ultrathin sections were studied with the electron microscope. The fine structure of ceroid in the human atherosclerotic aorta appears to be heterogeneous, showing uniquely wavy, irregularly arranged lamellae lying within granular material of varying electron density. The lamellar structure shows regular and alternating parallel electron-dense and electron-lucent zones which we believe to be characteristic of ceroid.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

1967 ◽  
Vol 25 ◽  
pp. 96-97
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
E Coli ◽  
Receptor Sites ◽  
Rigid Cell Wall ◽  
Host Cell Surface ◽  
Bacterial Viruses ◽  
Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

Fine Structure of Interdental Cells in the Mouse Cochlea

1970 ◽  
Vol 28 ◽  
pp. 140-141
Author(s):  
Roberta M. Bruck
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Young Adult ◽  
Uranyl Acetate ◽  
Ground Substance ◽  
Tectorial Membrane ◽  
Lead Citrate ◽  
Unusual Structure ◽  
Thin Sections ◽  
Collagenous Fibers

An unusual structure in the cochlea is the spiral limbus; this periosteal tissue consists of stellate fibroblasts and collagenous fibers embedded in a translucent ground substance. The collagenous fibers are arranged in vertical columns (the auditory teeth of Haschke). Between the auditory teeth are interdental furrows in which the interdental cells are situated. These epithelial cells supposedly secrete the tectorial membrane.The fine structure of interdental cells in the rat was reported by Iurato (1962). Since the mouse appears to be different, a description of the fine structure of mouse interdental cells' is presented. Young adult C57BL/6J mice were perfused intervascularly with 1% paraformaldehyde/ 1.25% glutaraldehyde in .1M phosphate buffer (pH7.2-7.4). Intact cochlea were decalcified in .1M EDTA by the method of Baird (1967), postosmicated, dehydrated, and embedded in Araldite. Thin sections stained with uranyl acetate and lead citrate were examined in a Phillips EM-200 electron microscope.

Use of Uranium-Labeled Antibodies for Electron Microscopic Localization of Various Antigens in Mammalian Cells

1967 ◽  
Vol 25 ◽  
pp. 136-137
Author(s):  
J. P. Petrali ◽  
E. J. Donati ◽  
L. A. Sternberger
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Specific Antiserum ◽  
Electron Microscopic ◽  
E Coli ◽  
Cytoplasmic Membranes ◽  
Viral Progeny ◽  
Ultrathin Sections ◽  
Electron Microscopic Localization

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.

Diagnosis of Silica Induced Granulomatous Hypersensitivity

1982 ◽  
Vol 40 ◽  
pp. 336-337
Author(s):  
C. W. Mehard ◽  
W. L. Epstein
Keyword(s):  
Electron Microscope ◽  
White Female ◽  
X Rays ◽  
Blood Tests ◽  
Analytical Electron ◽  
Analytical Electron Microscope

The underlying cause of a disease may not he readily apparent but may have a long history in development. We report one such case which was diagnosed with the aid of the analytical electron microscope.The patient, a 48 yr. old white female, developed a tender nodule on the sole of her foot in December, 1981. Subsequently additional lesions developed on the same foot resulting in deep pain and tenderness. Superficial lesions also extended up to the knee on both legs. No abnormalities were revealed in blood tests or chest X-rays.

Fine structure of the retina of the giant scallop, Placopecten magellanicus

1984 ◽  
Vol 42 ◽  
pp. 312-313
Author(s):  
C.V.L. Powell
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Light Intensity ◽  
Scanning Electron Microscope ◽  
Eye Development ◽  
Preliminary Observation ◽  
Columnar Epithelium ◽  
Placopecten Magellanicus ◽  
Environmental Light ◽  
Scanning Electron

The overall fine structure of the eye in Placopecten is similar to that of other scallops. The optic tentacle consists of an outer columnar epithelium which is modified into a pigmented iris and a cornea (Fig. 1). This capsule encloses the cellular lens, retina, reflecting argentea and the pigmented tapetum. The retina is divided into two parts (Fig. 2). The distal retina functions in the detection of movement and the proximal retina monitors environmental light intensity. The purpose of the present study is to describe the ultrastructure of the retina as a preliminary observation on eye development. This is also the first known presentation of scanning electron microscope studies of the eye of the scallop.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

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