Chapter 11 Biochemical Studies of the Mammalian Exosome with Intact Cells

2008 ◽  
pp. 211-226 ◽  
Author(s):  
Geurt Schilders ◽  
Ger J.M. Pruijn
Keyword(s):  
Intact Cells ◽  
Biochemical Studies

scholarly journals Biochemical Studies on Active Transport

1968 ◽  
Vol 52 (1) ◽  
pp. 279-295 ◽  
Author(s):  
Arthur B. Pardee
Keyword(s):  
Active Transport ◽  
Cell Function ◽  
Specific Protein ◽  
Transport Systems ◽  
Initial State ◽  
Intact Cells ◽  
The Past ◽  
Biochemical Studies ◽  
Active Transport Process

The active transport process, so important in cell function, has been studied in the past with intact cells. Models which have arisen from this work all depend on: first, a specific protein to recognize the substrate; second, translocation of the substrate across the cell membrane; third, release of substrate within the cell and restoration of the system to its initial state. These steps are adequate for facilitated transport, but in active transport an energy input is required to maintain a concentration gradient. Parts of transport systems have been isolated recently. A protein which specifically recognizes ß-galactosides has been partially purified. In another case, a protein that appears to be the recognition part of the sulfate transport system of Salmonella typhimurium has been crystallized, and many of its properties have been described. The role of this protein in recognition and in translocation is discussed. Also proteins that phosphorylate a variety of sugars as they enter the cell's interior provide a mechanism for concentrating sugars as their phosphates, against a gradient.

Investor-State Dispute Settlement under NAFTA Chapter 11: The Shape of Things to Come?

1998 ◽  
Vol 35 ◽  
pp. 263-290
Author(s):  
J. Anthony VanDuzer
Keyword(s):  
Free Trade Agreement ◽  
Dispute Settlement ◽  
Trade Agreement ◽  
Minimum Standards ◽  
The North ◽  
State Behaviour ◽  
Nafta Chapter 11 ◽  
To Come ◽  
The Right

SummaryRecently, there has been a proliferation of international agreements imposing minimum standards on states in respect of their treatment of foreign investors and allowing investors to initiate dispute settlement proceedings where a state violates these standards. Of greatest significance to Canada is Chapter 11 of the North American Free Trade Agreement, which provides both standards for state behaviour and the right to initiate binding arbitration. Since 1996, four cases have been brought under Chapter 11. This note describes the Chapter 11 process and suggests some of the issues that may arise as it is increasingly resorted to by investors.

Oncornavirus assembly at the cell surface revealed in replicas of freeze-dried cells

1978 ◽  
Vol 36 (2) ◽  
pp. 354-355
Author(s):  
Anthony Demsey ◽  
Christopher W. Stackpole
Keyword(s):  
Cell Surface ◽  
Surface Membrane ◽  
Viral Origin ◽  
Intact Cells ◽  
Structural Formation ◽  
Virus Core ◽  
Freeze Dried ◽  
Cacodylate Buffer ◽  
Surface Replica ◽  
Leukemia Viruses

The murine leukemia viruses are type-C oncornaviruses, and their release from the host cell involves a “budding” process in which the newly-forming, RNA-containing virus core becomes enveloped by modified cell surface membrane. Previous studies revealed that the released virions possess a dense array of 10 nm globular projections (“knobs”) on this envelope surface, and that these knobs contain a 70, 000 MW glycoprotein (gp70) of viral origin. Taking advantage of this distinctive structural formation, we have developed a procedure for freeze-drying and replication of intact cells which reveals surface detail superior to other surface replica techniques, and sufficient to detect even early stages of virus budding by localized aggregation of these knobs on the cell surface.Briefly, cells growing in monolayer are seeded onto round glass coverslips 10-12 mm in diameter. After a period of growth, cells are fixed in situ for one hour, usually with 1% OsO4 in 0. 1 M cacodylate buffer, and rinsed in distilled water.

Ruthenium Red Staining of Human Hard Keratin Fibers

1982 ◽  
Vol 40 ◽  
pp. 278-279
Author(s):  
M. C. Buhrer ◽  
R. A. Mathews
Keyword(s):  
Human Hair ◽  
Ruthenium Red ◽  
Acid Mucopolysaccharides ◽  
Biochemical Studies ◽  
Keratin Fibers ◽  
Ruthenium Red Staining ◽  
Extracellular Materials

Ruthenium red has been used as a stain to demonstrate a variety of extracellular materials, especially acid mucopolysaccharides. It also reacts with certain intracellular and extracellular lipids. Since biochemical studies in our laboratory demonstrated the presence of a variety of monosaccharides in human hair ruthenium red staining procedures were adopted in order to evaluate the presence and morphological location of acid oligosaccharides in the keratinized aspect of hair.

Effects of Hypophysectomy on the Fine Structure of Rat Liver Cells

1967 ◽  
Vol 25 ◽  
pp. 156-157
Author(s):  
Robert R. Cardell
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Rat Liver ◽  
Liver Cell ◽  
Anterior Pituitary ◽  
Liver Cells ◽  
Biochemical Studies ◽  
Liver Functions ◽  
Rat Liver Cells ◽  
And Control

Hypophysectomy of the rat renders this animal deficient in the hormones of the anterior pituitary gland, thus causing many primary and secondary hormonal effects on basic liver functions. Biochemical studies of these alterations in the rat liver cell are quite extensive; however, relatively few morphological observations on such cells have been recorded. Because the available biochemical information was derived mostly from disrupted and fractionated liver cells, it seemed desirable to examine the problem with the techniques of electron microscopy in order to see what changes are apparent in the intact liver cell after hypophysectomy. Accordingly, liver cells from rats which had been hypophysectomized 5-120 days before sacrifice were studied. Sham-operated rats served as controls and both hypophysectomized and control rats were fasted 15 hours before sacrifice.

Detection and mapping of interactions between chromatin and the nuclear envelope in drosophila embryos

1995 ◽  
Vol 53 ◽  
pp. 764-765
Author(s):  
W.F. Marshall ◽  
A.F. Dernburg ◽  
B. Harmon ◽  
J.W. Sedat
Keyword(s):  
Nuclear Envelope ◽  
Chromatin Condensation ◽  
Three Dimensional ◽  
Physiological Role ◽  
Nuclear Surface ◽  
Intact Cells ◽  
Molecular Determinants ◽  
Surface Harmonic ◽  
Drosophila Embryos

Interactions between chromatin and nuclear envelope (NE) have been implicated in chromatin condensation, gene regulation, nuclear reassembly, and organization of chromosomes within the nucleus. To further investigate the physiological role played by such interactions, it will be necessary to determine which loci specifically interact with the nuclear envelope. This will not only facilitate identification of the molecular determinants of this interaction, but will also allow manipulation of the pattern of chromatin-NE interactions to probe possible functions. We have developed a microscopic approach to detect and map chromatin-NE interactions inside intact cells.Fluorescence in situ hybridization (FISH) is used to localize specific chromosomal regions within the nucleus of Drosophila embryos and anti-lamin immunofluorescence is used to detect the nuclear envelope. Widefield deconvolution microscopy is then used to obtain a three-dimensional image of the sample (Fig. 1). The nuclear surface is represented by a surface-harmonic expansion (Fig 2). A statistical test for association of the FISH spot with the surface is then performed.

Rhabdomyolysis in DOMS

1999 ◽  
Vol 38 (05) ◽  
pp. 164-168 ◽  
Author(s):  
Gloria Ruiz Hernandez ◽  
C. Sanchez Marchori ◽  
J. Munoz Moliner ◽  
C. Martinez Carsi
Keyword(s):  
Bone Scintigraphy ◽  
Previous History ◽  
Biochemical Studies ◽  
History Of ◽  
Increased Activity

SummaryA 26-year-old man with a previous history of external twin bursitis was remitted to our Department for a bone scintigraphy. Before the study, the patient performed an elevated number of intense sprints. Bone scintigraphy showed a bilaterally increased activity in both anterior rectum muscles suggesting rhabdomyolysis. Biochemical studies and MRT confirmed the diagnosis.

The Uptake of Adenine by Isolated Human Platelet Membranes

1974 ◽  
Vol 32 (02/03) ◽  
pp. 457-464
Author(s):  
Paul C. French ◽  
Jan J. Sixma ◽  
Holm Holmsen
Keyword(s):  
Human Platelet ◽  
Facilitated Diffusion ◽  
Adenine Phosphoribosyltransferase ◽  
Ph Optimum ◽  
Intact Cells ◽  
Platelet Membranes ◽  
Group Translocation ◽  
Triton X

SummaryAdenine uptake into isolated platelet membranes had about the same Km (151 ± 21 • 9 nM) as uptake into intact cells (159 ± 21 nM) and was also competitively inhibited by papaverine and hypoxanthine. No uptake occurred at 0° and accumulated adenine was converted to AMP. AMP was not firmly bound to protein as judged by chromatography of triton X-100 solubilized membranes on Sephadex G25. The pH optimum for adenine uptake was at pH 5-5. Exogenous 5-phosphoribosyl-l-pyrophos- phate strongly stimulated uptake. These data may be explained by uptake of adenine by facilitated diffusion followed by conversion to AMP by adenine phosphoribosyltransferase but group translocation cannot be entirely excluded.

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