Fine structure of peripheral terminations in the porous sensillar cone of larvae of Ctenicera destructor (Brown) (Coleoptera, Elateridae), and probable fixation artifacts

1971 ◽  
Vol 49 (6) ◽  
pp. 789-799 ◽  
Author(s):  
R. Y. Zacharuk
Keyword(s):  
Fine Structure ◽  
Glutaraldehyde Fixation ◽  
Dendritic Branches ◽  
Peripheral Sensory ◽  
Ammoniacal Silver ◽  
Ctenicera Destructor

Nodes occur naturally on the dendritic branches in the receptor-lymph cavity of the antennal sensory cone in larvae of Ctenicera destructor. They increase in number, are often greatly expanded, and may separate from the dendrites as fixation artifacts. Extracellular dictyosomes originate from terminal nodes of the dendritic branches. These dictyosomes secrete vesicles, believed to contain lipoidal substances, directly into the fluid in the receptor cavity. These vesicles either coalesce into large lipoidal globules which produce the peripheral sensory tubules that traverse pores in the covering cuticle, or themselves attach directly to the tubules. The sensory tubules are lipoidal in nature. It is suggested that they serve to conserve moisture in the sensillum and to channel stimulating molecules through the cuticle to the lymph in the receptor cavity. The dendrites are not attached directly to the sensory tubules, but are believed to gain contact with the stimulating molecules through the receptor lymph. The lipoidal substance for sensory tubule secretion is probably transported into the sensory cone by the neurotubules within the dendrites. The results from a technique using glutaraldehyde fixation, ammoniacal silver treatment, and lead staining, without osmium fixation, are described and discussed.

Improved preservation of fine structure of deep-sea microorganisms by freeze-substitution after glutaraldehyde fixation

2011 ◽  
Vol 60 (4) ◽  
pp. 283-287 ◽  
Author(s):  
M. Yamaguchi ◽  
Y. Namiki ◽  
H. Okada ◽  
K. Uematsu ◽  
A. Tame ◽  
...  
Keyword(s):  
Fine Structure ◽  
Deep Sea ◽  
Freeze Substitution ◽  
Glutaraldehyde Fixation

Lipid in Erysiphe graminis hordei and its possible role during germination

1970 ◽  
Vol 16 (11) ◽  
pp. 1041-1044 ◽  
Author(s):  
W. E. McKeen
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Erysiphe Graminis ◽  
Glutaraldehyde Fixation ◽  
Sudan Black B ◽  
Erysiphe Graminis Hordei ◽  
Sudan Iv ◽  
Mother Cells ◽  
Hyphal Tip

Osmiophilic bodies appear in parts of the colonial growth of Erysiphe graminis DC. f. sp. hordei Em Marchal culture CR3 growing on the susceptible commercial Keystone variety of barley. They are readily observed by the light and electron microscope after osmium tetroxide staining and are abundant in conidiophores, conidia, and mycelium except in haustorial mother cells, in which they are usually absent. The metabolism of haustorial mother cells is distinct and the fine structure of adjoining cells is frequently different. Osmiophilic bodies are absent from the growing hyphal tip, but gradually increase in number and size further back in the terminal cell. Electron micrographs show that they are intracytoplasmic, intravacuolar, and up to 1 μ in diameter. When the colony is washed with acetone or alcohol rather than with aqueous buffer, after glutaraldehyde fixation, before osmium tetroxide fixation, the osmiophilic bodies are removed, indicating that they are lipids. Fat stains, Sudan black B, and Sudan IV stain these bodies. Perhaps the water needs of the germinating conidium are met in part by the oxidation of fats.

scholarly journals SARCOLEMMAL INVAGINATIONS CONSTITUTING THE T SYSTEM IN FISH MUSCLE FIBERS

1964 ◽  
Vol 22 (3) ◽  
pp. 675-696 ◽  
Author(s):  
Clara Franzini-armstrong ◽  
Keith R. Porter
Keyword(s):  
Fine Structure ◽  
Osmium Tetroxide ◽  
Striated Muscle ◽  
Muscle Fibers ◽  
Fish Muscle ◽  
Structural Features ◽  
The Body ◽  
Glutaraldehyde Fixation ◽  
Striated Muscle Fibers ◽  
T System

Striated muscle fibers from the body and tail myotomes of a fish, the black Mollie, have been examined with particular attention to the sarcoplasmic reticulum (SR) and transverse tubular (or T) system. The material was fixed in osmium tetroxide and in glutaraldehyde, and the images provided by the two kinds of fixatives were compared. Glutaraldehyde fixes a fine structure that is broadly comparable with that preserved by osmium tetroxide alone but differs in some significant details. Especially significant improvements were obtained in the preservation of the T system, that is, the system of small tubules that pervades the fiber at every Z line or A-I junction level. As a result of this improved glutaraldehyde fixation, the T system is now clearly defined as an entity of fine structure distinct from the SR but uniquely associated with the SR and myofibrils. Glutaraldehyde fixation also reveals that the T system is a sarcolemmal derivative that retains its continuity with the sarcolemma and limits a space that is in direct communication with the extracellular environment. These structural features favor the conclusion that the T system plays a prominent role in the fast intracellular conduction of the excitatory impulse. The preservation of other elements of muscle fine structure, including the myofibrils, seems for reasons discussed, to be substantially improved by glutaraldehyde.

scholarly journals PRESERVATION OF MYELIN LAMELLAR STRUCTURE IN THE ABSENCE OF LIPID

1967 ◽  
Vol 34 (3) ◽  
pp. 817-826 ◽  
Author(s):  
Leonard Napolitano ◽  
Francis Lebaron ◽  
Joseph Scaletti
Keyword(s):  
Fatty Acids ◽  
Liquid Chromatography ◽  
Fine Structure ◽  
Electron Microscope ◽  
Lamellar Structure ◽  
Osmium Tetroxide ◽  
Gas Liquid Chromatography ◽  
Glutaraldehyde Fixation ◽  
Thin Sections ◽  
Sciatic Nerves

The fine structure of myelin was studied in glutaraldehyde-fixed rat sciatic nerves depleted of lipid by acetone, chloroform:methanol (2:1 v/v), and chloroform:methanol:concentrated HCl (200:100:1, v/v/v). One portion of each of these nerves, plus the extracts, was saponified and analyzed by gas-liquid chromatography for fatty acids. The remainder of each nerve was stained in osmium tetroxide in CCl4 (5g/100cc) and was embedded in Epon 812. Thin sections, examined in the electron microscope, revealed the preservation of myelin lamellar structure with a 170 A periodicity in nerves depleted of 98% of their lipids. Preservation of myelin lamellar structure depended on glutaraldehyde fixation and the introduction of osmium tetroxide in a nonpolar vehicle (CCl4) after the lipids had been extracted. It is concluded that the periodic lamellar structure in electron micrographs of myelin depleted of lipid results from the complexing of osmium tetroxide, plus uranyl and lead stains, with protein.

scholarly journals Further Observations on the Fine Structure of Chrysochromulina chiton with Special Reference to the Pyrenoid

1966 ◽  
Vol 1 (2) ◽  
pp. 187-192 ◽  
Author(s):  
IRENE MANTON
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Special Reference ◽  
Glutaraldehyde Fixation ◽  
Transparent Material ◽  
Chloroplast Membranes ◽  
Outer Pair ◽  
Translucent Material ◽  
Push Out ◽  
Local Accumulation

Developments associated with the surface of the projecting pyrenoids of Chrysochromulina chiton have been traced in outline after glutaraldehyde fixation. In the simplest condition the pyrenoidal core is separated from the cytoplasm by two superposed pairs of membranes, the outer pair being continuous with a layer of endoplasmic reticulum spread over the surface of the subtending chloroplast. Various stages in the formation and removal of an additional membrane-bounded cap of translucent material are illustrated and interpreted in terms of local accumulation of a temporary storage metabolite in the path of translocation of materials from the chloroplast into the cell. A cap is thought to begin as a blister involving the innermost pair of membranes which become pushed apart as the transparent material accumulates between them. A bulge, involving the outer of the two separated membranes plus contents of the blister, could then push out between meshes in the overlying endoplasmic reticulum before spreading laterally. This process is not light-dependent. It is suggested that enzymes localized between the chloroplast membranes in this region are acting on a soluble translocation metabolite. At mitosis, and shortly after, the capping material may be absent.

Quick-freeze, deep-etch rotary replication of Trypanosoma cruzi and Herpetomonas megaseliae

1984 ◽  
Vol 69 (1) ◽  
pp. 167-178
Author(s):  
T. Souto-Padron ◽  
W. de Souza ◽  
J.E. Heuser
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Trypanosoma Cruzi ◽  
Basal Body ◽  
Glutaraldehyde Fixation ◽  
Triton X

The fine structure of epimastigotes of Trypanosoma cruzi and promastigotes of Herpetomonas megaseliae was analysed in replicas of quick-frozen, freeze-fractured, deeply etched and rotary-replicated cells. Using control cells and cells treated with Triton X-100 before glutaraldehyde fixation, images were obtained that showed connections of the sub-pellicular microtubules with each other, with the plasma membrane, and with the endoplasmic reticulum. Images were also obtained that showed the DNA network in the kinetoplast. Filamentous structures were found to connect the kinetoplast to the basal body, and to connect the main basal body to the accessory one. In addition, deep-etch images of detergent-extracted flagella display dynein arm substructure and the filamentous architecture of the paraxial structures.

Fine structure of the antennal sensory appendix in the larva of Ctenicera destructor (Brown) (Elateridae: Coleoptera)

1971 ◽  
Vol 49 (2) ◽  
pp. 199-210 ◽  
Author(s):  
David A. Scott ◽  
R. Y. Zacharuk
Keyword(s):  
Sense Organ ◽  
Proximal Region ◽  
Central Complex ◽  
Body Region ◽  
Type I ◽  
Fiber System ◽  
Dendritic Branches ◽  
Membranous Septum ◽  
Complex Junction ◽  
Ctenicera Destructor

The antennal sensory appendix of Ctenicera destructor (Brown) appears to be a compound sensillum basiconicum formed by a union of about 12 individual sensilla. It is innervated by about 36 bipolar sense cells of type I, which occur usually in 12 groups of three neurons each. The sensory cuticle is large, cone-shaped, and abundantly perforated by a slit-tubule system. The dendrites of each group of neurons are enclosed distally by a single tubular cuticular sheath attached to the base of the cone by a suspensory fiber system. The ensheathed portion of the dendrites lies in a receptor-lymph cavity formed by the tormogen and accessory trophic cells. Distal dendritic branches pass below and occasionally enter inner pockets in the sensory cuticle, but no connections were seen between the slit-tubule system and the dendritic surfaces. About 12 of each of four types of cells are associated with the neurons in this sensillum: tormogen, trichogen, accessory trophic, and neurilemma. The ultrastructure and probable function of each type is described. A central, complex junction body region divides each dendrite into morphologically distinct distal and proximal region. All the cells associated with the sensillum are in a compact bundle, which is separated from adjacent sensilla within the antenna by a membranous septum. It is suggested that this sense organ has an olfactory function.

Fine Structure of Platelet Interaction with a New Microcrystalline Collagen Preparation

1974 ◽  
Vol 32 ◽  
pp. 58-59
Author(s):  
W. H. Zucker ◽  
R. G. Mason
Keyword(s):  
Fine Structure ◽  
Platelet Aggregation ◽  
Hydrochloric Acid ◽  
Whole Blood ◽  
Platelet Adhesion ◽  
Hemostatic Agent ◽  
Native Collagen ◽  
Fibrillar Morphology ◽  
Clinical Interest ◽  
New Form

Platelet adhesion initiates platelet aggregation and is an important component of the hemostatic process. Since the development of a new form of collagen as a topical hemostatic agent is of both basic and clinical interest, an ultrastructural and hematologic study of the interaction of platelets with the microcrystalline collagen preparation was undertaken.In this study, whole blood anticoagulated with EDTA was used in order to inhibit aggregation and permit study of platelet adhesion to collagen as an isolated event. The microcrystalline collagen was prepared from bovine dermal corium; milling was with sharp blades. The preparation consists of partial hydrochloric acid amine collagen salts and retains much of the fibrillar morphology of native collagen.

Pituitary Follicular Cells: Their Origin, Possible Function and Fate

1974 ◽  
Vol 32 ◽  
pp. 34-35
Author(s):  
E. Horvath ◽  
K. Kovacs ◽  
G. Penz ◽  
C. Ezrin
Keyword(s):  
Fine Structure ◽  
Secretory Granules ◽  
Follicular Cells ◽  
Human Pituitary ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
Junctional Complexes

Follicular structures, in the rat pituitary, composed of cells joined by junctional complexes and possessing few organelles and few, if any, secretory granules, were first described by Farquhar in 1957. Cells of the same description have since been observed in several species including man. The importance of these cells, however, remains obscure. While studying human pituitary glands, we have observed wide variations in the fine structure of follicular cells which may lead to a better understanding of their morphogenesis and significance.

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