scholarly journals THE STRUCTURE OF FLIGHT MUSCLE SARCOSOMES IN THE BLOWFLY CALLIPHORA ERYTHROCEPHALA (DIPTERA)

1963 ◽  
Vol 19 (1) ◽  
pp. 115-138 ◽  
Author(s):  
David S. Smith
Keyword(s):  
Flight Muscle ◽  
Parallel Plates ◽  
Mitochondrial Membranes ◽  
Submitochondrial Particles ◽  
Electron Microscopic ◽  
Calliphora Erythrocephala ◽  
Large Numbers ◽  
The Matrix ◽  
Spherical Head ◽  
Inner Limiting Membranes

The electron microscopic structure of sectioned indirect flight muscle fibers of the blowfly Calliphora is described. Particular attention is paid to the organization of the sarcosomes (mitochondria) of this tissue, and this description is accompanied by an account of the appearance of these bodies in negatively stained preparations. In sectioned material, it has been shown that these sarcosomes are similar to other mitochondria in the disposition of the outer and inner limiting membranes, but that the cristae, confluent with the latter, are unusually regular, and form parallel plates, containing circular fenestrations forming cylindrical channels within the matrix. Negatively stained preparations of disrupted sarcosomes reveal that both the outer limiting membrane and the cristae membranes bear large numbers of small particles, similar in appearance to those described by Fernández-Morgán and others in various mitochondria. In Calliphora, these particles consist of a sub-spherical "head" and a cylindrical "stalk," and appear to be arranged on the mitochondrial membranes either randomly distributed, or collected into circular or elongated groups. Recent suggestions concerning the nature of these submitochondrial particles are discussed, and an attempt is made to correlate the aspects of organization of Calliphora sarcosomes, revealed by conventional sectioning of the "intact" structures, and by negative staining of sarcosomal derivatives.

Observations on the fragmentation of isolated flight-muscle mitochondria from Calliphora erythrocephala (Diptera)

1965 ◽  
Vol 161 (984) ◽  
pp. 403-420 ◽  
Keyword(s):  
Cytochrome Oxidase ◽  
Flight Muscle ◽  
Biochemical Study ◽  
Sucrose Density Gradient ◽  
Negative Staining ◽  
Electron Microscopic ◽  
Concentrated Suspension ◽  
Calliphora Erythrocephala ◽  
Isolated Mitochondria ◽  
Middle Fraction

A combined electron-microscopic and biochemical study has been made of the disintegration of isolated mitochondria from asynchronous flight muscle of the blowfly Calliphora erythrocephala . These mitochondria are particularly suitable because they can be easily isolated free from other intracellular structures and because of the regularity of their closely packed cristae, seen in fixed (sectioned) and unfixed, negatively stained material. Fragmentation occurs on treatm ent with distilled water, or more rapidly and extensively on sonication. The first stage detected in the disruption of the plate-like cristae is the formation of tubular elements, observed in sectioned preparations. These were seen after negative staining as irregular ribbons, studded with the stalked particles, 80 to 95 Å in diameter, first described by Fernández-Morán. Further fragmentation of the tubules yielded rounded fragments, about 200 to 2000 Å in diameter, apparently by transverse splitting and lateral ‘budding’. These were vesicles, as shown in sectioned material, bearing stalked particles seen by negative staining. After removal of the larger fragments by centrifugation, sonicated material was fractionated on a sucrose density gradient. Protein, cytochrome oxidase activity and rate of reduction of ferricyanide by succinate were determined. A middle fraction with the highest enzymatic activity/ml. of sucrose was found to be a concentrated suspension of vesicles, 200 to 500 Å in diameter, still bearing stalked particles. Little recognizable material was seen in a fraction near the top of the gradient with minimal activity and maximal concentration of (‘soluble’) protein. Available evidence indicates that the cytochrome oxidase and succinate-ferricyanide activities become associated with the vesicles. The activity/mg of protein of the most active fraction was not more than double that of the sonicate. The smaller fragments seemed to be more deficient in cytochrome c than the larger. The stalked particles were firmly attached to cristae, tubules and vesicles, and attempts to remove them were unsuccessful.

scholarly journals ULTRASTRUCTURE OF ISOLATED KIDNEY MITOCHONDRIA TREATED WITH PHLORIZIN AND ATP

1964 ◽  
Vol 23 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Mario H. Burgos ◽  
Agustin Aoki ◽  
Fabio L. Sacerdote
Keyword(s):  
Rat Kidney ◽  
Heterogeneous Population ◽  
Kidney Cortex ◽  
Mitochondrial Membranes ◽  
Electron Microscopic ◽  
Isolated Kidney ◽  
Rat Kidney Cortex ◽  
Kidney Mitochondria ◽  
Isolated Mitochondria ◽  
The Matrix

Direct electron microscopic evidence is reported of the ultrastructure of mitochondrial membranes and compartments in mitochondria isolated in 0.5 M sucrose from the rat kidney cortex and the experimental changes they undergo with phlorizin and ATP treatment. A heterogeneous population of mitochondria is recognized under control conditions. The mitochondria appear to be of 3 main types, normal, swollen, and contracted. Under phlorizin treatment, most of the mitochondria swell in less than 15 minutes, apparently at the expense of the matrix. Treatment with ATP, on the other hand, produces, during the same time, a marked contraction of the isolated mitochondria, with many refoldings of the inner membrane and marked increase in the electron opacity of the matrix. It is concluded from these observations that mitochondrial swelling and contraction should be related mainly to the matrix content.

Cytoplasmic Granules in Lymphocytes from Rats Dosed with SK&F 14336-D

1971 ◽  
Vol 29 ◽  
pp. 556-557
Author(s):  
T. G. Merrill ◽  
B. J. Payne ◽  
A. J. Tousimis
Keyword(s):  
Lipid Storage ◽  
Pokeweed Mitogen ◽  
Electron Microscopic ◽  
Cytoplasmic Granules ◽  
Storage Diseases ◽  
Tay Sachs Disease ◽  
Large Numbers ◽  
Microscopic Studies ◽  
Neurovisceral Lipidosis

Rats given SK&F 14336-D (9-[3-Dimethylamino propyl]-2-chloroacridane), a tranquilizing drug, developed an increased number of vacuolated lymphocytes as observed by light microscopy. Vacuoles in peripheral blood of rats and humans apparently are rare and are not usually reported in differential counts. Transforming agents such as phytohemagglutinin and pokeweed mitogen induce similar vacuoles in in vitro cultures of lymphocytes. These vacuoles have also been reported in some of the lipid-storage diseases of humans such as amaurotic familial idiocy, familial neurovisceral lipidosis, lipomucopolysaccharidosis and sphingomyelinosis. Electron microscopic studies of Tay-Sachs' disease and of chloroquine treated swine have demonstrated large numbers of “membranous cytoplasmic granules” in the cytoplasm of neurons, in addition to lymphocytes. The present study was undertaken with the purpose of characterizing the membranous inclusions and developing an experimental animal model which may be used for the study of lipid storage diseases.

Determination of the phase structure of polymerblends by electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 492-493
Author(s):  
Dr. G. Kaemof
Keyword(s):  
Screw Extruder ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Single Screw Extruder ◽  
Transmission Electron ◽  
The Matrix ◽  
Twin Screw ◽  
Special Case ◽  
Microscopic Investigations

A mixture of polycarbonate (PC) and styrene-acrylonitrile-copolymer (SAN) represents a very good example for the efficiency of electron microscopic investigations concerning the determination of optimum production procedures for high grade product properties.The following parameters have been varied:components of charge (PC : SAN 50 : 50, 60 : 40, 70 : 30), kind of compounding machine (single screw extruder, twin screw extruder, discontinuous kneader), mass-temperature (lowest and highest possible temperature).The transmission electron microscopic investigations (TEM) were carried out on ultra thin sections, the PC-phase of which was selectively etched by triethylamine.The phase transition (matrix to disperse phase) does not occur - as might be expected - at a PC to SAN ratio of 50 : 50, but at a ratio of 65 : 35. Our results show that the matrix is preferably formed by the components with the lower melting viscosity (in this special case SAN), even at concentrations of less than 50 %.

An SEM study of raphide crystal initials in the leaves of vitis (grape)

1995 ◽  
Vol 53 ◽  
pp. 984-985
Author(s):  
H. J. Arnott ◽  
M. A. Webb ◽  
L. E. Lopez
Keyword(s):  
Calcium Oxalate ◽  
Water Soluble ◽  
Calcium Oxalate Crystals ◽  
Calcium Oxalate Crystal ◽  
Oxalate Crystals ◽  
Large Numbers ◽  
Sem Study ◽  
The Matrix ◽  
Crystal Cells ◽  
Crystal Idioblast

Many papers have been published on the structure of calcium oxalate crystals in plants, however, few deal with the early development of crystals. Large numbers of idioblastic calcium oxalate crystal cells are found in the leaves of Vitis mustangensis, V. labrusca and V. vulpina. A crystal idioblast, or raphide cell, will produce 150-300 needle-like calcium oxalate crystals within a central vacuole. Each raphide crystal is autonomous, having been produced in a separate membrane-defined crystal chamber; the idioblast''s crystal complement is collectively embedded in a water soluble glycoprotein matrix which fills the vacuole. The crystals are twins, each having a pointed and a bidentate end (Fig 1); when mature they are about 0.5-1.2 μn in diameter and 30-70 μm in length. Crystal bundles, i.e., crystals and their matrix, can be isolated from leaves using 100% ETOH. If the bundles are treated with H2O the matrix surrounding the crystals rapidly disperses.

Structure of contact sites between the outer and inner mitochondrial membranes investigated by HVEM tomography

1996 ◽  
Vol 54 ◽  
pp. 966-967
Author(s):  
C.A. Mannella ◽  
K.F. Buttle ◽  
K.A. O‘Farrell ◽  
A. Leith ◽  
M. Marko
Keyword(s):  
Liver Mitochondrion ◽  
Adenine Nucleotide ◽  
Protein Complexes ◽  
Mitochondrial Membranes ◽  
Electron Microscopic ◽  
Contact Sites ◽  
Transmission Electron ◽  
Precursor Proteins ◽  
Membrane Contacts ◽  
And Function

Early transmission electron microscopy of plastic-embedded, thin-sectioned mitochondria indicated that there are numerous junctions between the outer and inner membranes of this organelle. More recent studies have suggested that the mitochondrial membrane contacts may be the site of protein complexes engaged in specialized functions, e.g., import of mitochondrial precursor proteins, adenine nucleotide channeling, and even intermembrane signalling. It has been suggested that the intermembrane contacts may be sites of membrane fusion involving non-bilayer lipid domains in the two membranes. However, despite growing interest in the nature and function of intramitochondrial contact sites, little is known about their structure.We are using electron microscopic tomography with the Albany HVEM to determine the internal organization of mitochondria. We have reconstructed a 0.6-μm section through an isolated, plasticembedded rat-liver mitochondrion by combining 123 projections collected by tilting (+/- 70°) around two perpendicular tilt axes. The resulting 3-D image has confirmed the basic inner-membrane organization inferred from lower-resolution reconstructions obtained from single-axis tomography.

scholarly journals Characterization of components of Z-bands in the fibrillar flight muscle of Drosophila melanogaster.

1989 ◽  
Vol 109 (5) ◽  
pp. 2157-2167 ◽  
Author(s):  
J D Saide ◽  
S Chin-Bow ◽  
J Hogan-Sheldon ◽  
L Busquets-Turner ◽  
J O Vigoreaux ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Monoclonal Antibodies ◽  
Flight Muscle ◽  
Cross Reactivity ◽  
Antigenic Determinants ◽  
Immunogold Staining ◽  
Thick Filaments ◽  
The Matrix ◽  
Flight Muscles

Twelve monoclonal antibodies have been raised against proteins in preparations of Z-disks isolated from Drosophila melanogaster flight muscle. The monoclonal antibodies that recognized Z-band components were identified by immunofluorescence microscopy of flight muscle myofibrils. These antibodies have identified three Z-disk antigens on immunoblots of myofibrillar proteins. Monoclonal antibodies alpha:1-4 recognize a 90-100-kD protein which we identify as alpha-actinin on the basis of cross-reactivity with antibodies raised against honeybee and vertebrate alpha-actinins. Monoclonal antibodies P:1-4 bind to the high molecular mass protein, projectin, a component of connecting filaments that link the ends of thick filaments to the Z-band in insect asynchronous flight muscles. The anti-projectin antibodies also stain synchronous muscle, but, surprisingly, the epitopes here are within the A-bands, not between the A- and Z-bands, as in flight muscle. Monoclonal antibodies Z(210):1-4 recognize a 210-kD protein that has not been previously shown to be a Z-band structural component. A fourth antigen, resolved as a doublet (approximately 400/600 kD) on immunoblots of Drosophila fibrillar proteins, is detected by a cross reacting antibody, Z(400):2, raised against a protein in isolated honeybee Z-disks. On Lowicryl sections of asynchronous flight muscle, indirect immunogold staining has localized alpha-actinin and the 210-kD protein throughout the matrix of the Z-band, projectin between the Z- and A-bands, and the 400/600-kD components at the I-band/Z-band junction. Drosophila alpha-actinin, projectin, and the 400/600-kD components share some antigenic determinants with corresponding honeybee proteins, but no honeybee protein interacts with any of the Z(210) antibodies.

On the scattering of sound by two semi-infinite parallel staggered plates - I. Explicit matrix Wiener-Hopf factorization

1988 ◽  
Vol 420 (1858) ◽  
pp. 131-156 ◽  
Keyword(s):  
Asymptotic Expression ◽  
Series Representation ◽  
Auxiliary Function ◽  
Sound Waves ◽  
Parallel Plates ◽  
Hopf Equation ◽  
Product Decomposition ◽  
Matrix Kernel ◽  
Wave Fields ◽  
The Matrix

This paper discusses the two-dimensional scattering of sound waves by two semi-infinite rigid parallel plates. The plates are staggered, so that a line in the plane of the motion passing through both edges is not in general perpendicular to the plane of either plate. The problem is formulated as a matrix Wiener-Hopf functional equation, which exhibits the difficulty of a kernel containing exponentially growing elements. We show how this difficulty may be overcome by constructing an explicit product decomposition of the matrix kernel with both factors having algebraic behaviour at infinity. This factorization is written in terms of a single entire auxiliary function that has a simple infinite series representation. The Wiener-Hopf equation is solved for arbitrary incident wave fields and we derive an asymptotic expression for the field scattered to infinity; the latter includes the possibility of propagating modes in the region between the plates. In part II of this work we will evaluate our solution numerically and obtain some analytical estimates in a number of physically interesting limits.

Microstructure and Tensile Deformation Features of Tandem Hot Rolling GH4169 Superalloy

2014 ◽  
Vol 33 (2) ◽  
pp. 131-136
Author(s):  
Zhenrong Li ◽  
Chunlei Ma ◽  
Sugui Tian ◽  
Liqing Chen ◽  
Xianghua Liu
Keyword(s):  
Hot Rolling ◽  
Tensile Deformation ◽  
Solution Treatment ◽  
Microstructure Observation ◽  
Large Numbers ◽  
Initiation And Propagation ◽  
The Matrix ◽  
Deformation Features ◽  
Δ Phase ◽  
Property Measurement

AbstractBy means of solution treatment, microstructure observation and mechanical property measurement, the microstructure and tensile deformation features of tandem hot rolling GH4169 alloy have been investigated. Results shown that, after solution treatment and aging, large numbers of the spherical γ′ phase and the flat-ellipsoidal γ″ phase dispersedly precipitate in the matrix, and acicular or short rod-like δ-phase discontinuously distribute along grain boundaries. As the tensile temperatures increases, the tensile strength and yield strength of the alloy gradually decrease. The tensile deformation features of the alloy are that the twinning and slipping dislocations with double orientations are activated in the matrix. In the later tension, the deformed dislocations pile up near the grain boundary to induce initiation and propagation of cracks due to stress concentration.

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