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Full-Text Articles in Life Sciences
Electro-Optical Imaging Of F-Actin And Endoplasmic Reticulum In Living And Fixed Plant Cells, Nina Stromgren Allen, Marty N. Bennett
Electro-Optical Imaging Of F-Actin And Endoplasmic Reticulum In Living And Fixed Plant Cells, Nina Stromgren Allen, Marty N. Bennett
Scanning Microscopy
Confocal and video micrographs of living and fixed alfalfa roots, onion epithelial and pear pollen cells illustrate the architecture of the cytoskeleton and endoplasmic reticulum in plant cells. Fixation of plant tissues to preserve cytoplasmic structure poses special problems. When possible, emphasis should be placed on the imaging of structures in stained living cells over time. The early events that occur when Nod factors or bacteria elicit nodule formation in alfalfa roots will illustrate several approaches to plant cell fixation, staining and imaging. The first observable events after Nod factor stimulation occur in root hairs and are changes in rates …
Apoptosis And Red Blood Cell Echinocytosis: Common Features, Alexei B. Chukhlovin
Apoptosis And Red Blood Cell Echinocytosis: Common Features, Alexei B. Chukhlovin
Scanning Microscopy
Apoptosis of nucleated blood cells induced by oxidants and/or reactive oxygen species is accompanied by the typical membrane pathology. Meanwhile, red blood cell (RBC) membrane. is a popular object for studying appropriate cytotoxic effects. Scanning electron microscopy provides a reliable tool for detecting the oxidative changes in RBC shape and size. Transition of normal discoid erythrocytes to crenated forms (echinocytes) is often induced by the same factors which cause apoptosis of blood cells, e.g., ionizing radiation and other reactive oxygen intermediate-inducing agents, exogenous oxidants, in vitro aging conditions, cytosolic calcium increase, etc. Moreover, the biochemical membrane alterations in oxidant-induced echinocytosis …
Cytoskeleton Architecture Of C6 Rat Glioma Cell Subclones Whole Mount Electron Microscopy And Immunogold Labeling, Wolfgang Bohn, Dörte Etzrodt, Roland Foisner, Gerhard Wiche, Peter Traub
Cytoskeleton Architecture Of C6 Rat Glioma Cell Subclones Whole Mount Electron Microscopy And Immunogold Labeling, Wolfgang Bohn, Dörte Etzrodt, Roland Foisner, Gerhard Wiche, Peter Traub
Scanning Microscopy
Whole mount electron microscopy of extracted cells combined with immunogold labeling techniques can be used to characterize the cytoskeletal architecture of cultured cells. As shown with subclones of the C6 rat glioma cell line, heavy metal shadowing was suitable for getting basic information concerning the arrangement of the various filament types within the networks. Pure carbon shadowing combined with immunogold double labeling proved to be optimal to identify linkages between filaments, to localize filament associated proteins and to follow the arrangement of filaments in dense arrays such as lamellipodiae and cell margins. Thin connecting filaments which interact with actin as …
Comparative Scanning, Transmission And Atomic Force Microscopy Of The Microtubular Cytoskeleton In Fenestrated Liver Endothelial Cells, Filip Braet, Ronald De Zanger, Wouter Kalle, Anton Raap, Hans Tanke, Eddie Wisse
Comparative Scanning, Transmission And Atomic Force Microscopy Of The Microtubular Cytoskeleton In Fenestrated Liver Endothelial Cells, Filip Braet, Ronald De Zanger, Wouter Kalle, Anton Raap, Hans Tanke, Eddie Wisse
Scanning Microscopy
Endothelial fenestrae control the exchange of fluids, solutes and particles between the sinusoidal lumen and the microvillous surface of the parenchymal cells. Fenestrae have a critical dimension in the order of 150-200 nm, making it necessary to use microscopes with a resolution better than the light microscope. Comparative whole-mount preparations of isolated, purified and cultured rat liver sinusoidal endothelial cells (LEC) were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Examination of detergent-extracted LEC by SEM and TEM shows an integral cytoskeleton: sieve plates are delineated by a sieve plate-associated cytoskeleton ring and …
X-Irradiation-Induced Disorganization Of Cytoskeletal Filaments And Cell Contacts In Ht29 Cells, Z. Somosy, M. Sass, G. Bognar, J. Kovacs, G. J. Koteles
X-Irradiation-Induced Disorganization Of Cytoskeletal Filaments And Cell Contacts In Ht29 Cells, Z. Somosy, M. Sass, G. Bognar, J. Kovacs, G. J. Koteles
Scanning Microscopy
Organization of cytoskeleton and cell contacts were studied by immunochemistry and electron microscopy in confluent HT29 cultured cells following exposure to 0.5 and 1.0 Gy doses of X-ray. Microtubules were resistant to irradiation, whereas, the actin and intermediate filaments disrupted rapidly following the treatment and their components appeared as clumps of actin and cytokeratin aggregates in the cytoplasm as demonstrated by immunochemistry. Loss of cell contacts and decrease in the number of desmosomes was also characteristic of irradiated cells. Electron microscopy revealed intact desmosomes in control cells and abnormal desmosomes in the irradiated samples characterized by the absence of tonofilaments. …
The Effects Of Diethyldithiocarbamate (Ddc) On The Astrocytic Cytoskeleton, Mary F. Mcmanus, Louis D. Trombetta
The Effects Of Diethyldithiocarbamate (Ddc) On The Astrocytic Cytoskeleton, Mary F. Mcmanus, Louis D. Trombetta
Scanning Microscopy
The dithiocarbamates are a group of compounds that are used extensively in industry, agriculture and medicine. Exposure to these compounds has caused deleterious effects to both the central and peripheral nervous systems. Cultured rat hippocampal astroglia treated with 35 μg/ml diethyldithiocarbamate (DDC) in media were studied for alterations to the cytoskeleton. Examination by both immunohistochemistry and scanning electron microscopy revealed disruption of the cytoskeletal elements. This occurred in a progressive time-dependent manner. Electrophoretic patterns demonstrated two cytoskeletal protein alterations. The microtubular protein, β-tubulin, appeared to have an altered mobility while the major intermediate filament protein, glial fibrillary acidic protein (GF …
Three-Dimensional Cytoskeletal Structures Of The Chinchilla Organ Of Corti: Scanning Electron Microscopy Application Of The Polyethylene Glycol Method, A. Nagasawa, R. V. Harrison, R. J. Mount, Y. Harada
Three-Dimensional Cytoskeletal Structures Of The Chinchilla Organ Of Corti: Scanning Electron Microscopy Application Of The Polyethylene Glycol Method, A. Nagasawa, R. V. Harrison, R. J. Mount, Y. Harada
Scanning Microscopy
We describe the application of a polyethylene glycol (PEG) embedding technique to examine the sensory and supporting structures of the inner ear. The chinchilla organ of Corti was exposed by cracking PEG embedded cochleas. A range of PEG molecular weights (2000-8000) were utilized; PEG 2000, with a melting point of 57°C was preferred. After removal of the PEG, the three-dimensional aspects of intracellular structures were observed using scanning electron microscopy. Filamentous elements in the hair cell cuticular plate and in the supporting cells were clearly observed, as was the mesh work of cross-linked actin filaments in the cuticular portion of …
Observations Of Colloidal Gold Labelled Platelet Microtubules: High Voltage Electron Microscopy And Low Voltage-High Resolution Scanning Electron Microscopy, R. M. Albrecht, J. Prudent, S. R. Simmons, J. Pawley, J. J. Choate
Observations Of Colloidal Gold Labelled Platelet Microtubules: High Voltage Electron Microscopy And Low Voltage-High Resolution Scanning Electron Microscopy, R. M. Albrecht, J. Prudent, S. R. Simmons, J. Pawley, J. J. Choate
Scanning Microscopy
18 nm colloidal gold-antitubulin and 4 nm colloidal gold-antitubulin were used to label microtubules in adherent, fully spread platelets. Both sizes of marker effectively labelled microtubules in the partially extracted platelets. However only the 4 nm gold penetrated the dense microfilament matrix of the inner filamentous zone so that portions of microtubules within this cytoskeletal zone could be tracked. The gold marker could be visualized well with 1 MeV high voltage transmission EM and with 5 kV or greater secondary imaging or 20 kV backscattered imaging of carbon only coated samples. 1 kV secondary imaging permitted high resolution imaging of …
Preparation Of Cytoskeletons Of Cells In Culture For High Resolution Scanning And Scanning Transmission Electron Microscopy, Paul B. Bell Jr., Margaretha Lindroth, Bengt-Arne Fredriksson
Preparation Of Cytoskeletons Of Cells In Culture For High Resolution Scanning And Scanning Transmission Electron Microscopy, Paul B. Bell Jr., Margaretha Lindroth, Bengt-Arne Fredriksson
Scanning Microscopy
In this tutorial we describe our methods for preparing detergent-extracted cytoskeletons for observation by high resolution scanning (SEM) and scanning transmission (STEM) electron microscopy. We both discuss the theoretical background and provide practical procedures for each of the following steps: cell culture on Formvar-coated gold grids; prefixation with aldehydes or protein crosslinking reagents (homobifunctional N-hydroxy-succinimide esters); extraction with Triton X-100 or Brij 58 detergent in microtubule stabilizing buffer; postfixation in formaldehyde and glutaraldehyde; dehydration; critical point and freeze drying; sputter coating with 1-2 nm of platinum or tungsten; and examination by SEM and both normal and inverted contrast STEM. These …
Myocyte Swelling And Plasmalemmal Integrity During Early Experimental Myocardial Ischemia In Vivo, Martin D. Sage, Robert B. Jennings
Myocyte Swelling And Plasmalemmal Integrity During Early Experimental Myocardial Ischemia In Vivo, Martin D. Sage, Robert B. Jennings
Scanning Microscopy
Using scanning and transmission electron microscopy, the structure of myocytes early in the phase of irreversible injury induced by 40 minutes of severe regional ischemia has been investigated, paying particular attention to the effects of cell swelling on the SEM appearance of the myocytes. Swollen myocytes showed an increased space beneath the plasmalemma and between organelles. True subsarcolemmal blebs were not seen and the attachment complexes between the Z-band and the underlying myofibrils remained intact. The proportion of the PS face of the plasmalemma which appeared "en face" (0.70%, SD:1.22 vs 5.0196, SD:3.72) in freeze-fracture faces of ischemic tissue was …
An Overview Of Platelet Structural Physiology, J. G. White
An Overview Of Platelet Structural Physiology, J. G. White
Scanning Microscopy
Marion Barnhart and her colleagues used light, phase contrast and scanning electron microscopy to provide a clear picture of platelet surface changes developing in response to aggregating agents. This review, in honor of Marion and her work, has sought to expand the horizon provided through study of surface alterations by peeling back the membrane of the platelet to reveal the dynamic world within. A cytoskeleton consisting of a circumferential microtubule and submembrane actin filaments supports the discoid shape of the resting cell. Following exposure to aggregating agents in suspension, to foreign surfaces or denuded blood vessels and to fibrin strands …
The Role Of The Cytoskeleton In Endothelial Repair, Avrum I. Gotlieb, Michael K. K. Wong, Patricia Boden, Alan Choo Fone
The Role Of The Cytoskeleton In Endothelial Repair, Avrum I. Gotlieb, Michael K. K. Wong, Patricia Boden, Alan Choo Fone
Scanning Microscopy
The injured endothelium undergoes rapid repair of areas of cell desquamation in order to maintain the structural integrity of the endothelial surface. Endothelial repair involves a series of processes which include endothelial cell spreading, translocation, and proliferation. These processes are well defined events which occur sequentially in time. Spreading and translocation are mediated by the cell cytoskeleton - F-actin microfilaments and microtubules and associated centrosomes. The regulation of these processes is complex and is likely due to soluble factors present at the site of injury which are released from activated endothelial cells, platelets, the subendothelial substratum, activated serum factors, and …
Megakaryocyte Motility And Platelet Formation, Robert M. Leven
Megakaryocyte Motility And Platelet Formation, Robert M. Leven
Scanning Microscopy
The mechanism of platelet formation is reviewed with special emphasis on the role of the cytoskeleton. The three major theories for platelet formation are by cytoplasmic budding, cytoplasmic dissolution or pseudopod formation. Most evidence indicates that platelets form as fragments of megakaryocyte pseudopodia. Pseudopodia formation is stimulated in vitro by thrombocytopenic rabbit plasma. It is inhibited by vincristine and altered by taxol. Cytochalasins cause pseudopodia to form in isolated megakaryocytes. Therefore, normal pseudopodia formation may depend on a combination of microfilament disorganization and microtubule elongation.
Cytoskeletal Changes During Adhesion And Release: A Comparison Of Human And Nonhuman Primate Platelets, J. C. Lewis, M. S. White, T. Prater, K. R. Porter, R. J. Steele
Cytoskeletal Changes During Adhesion And Release: A Comparison Of Human And Nonhuman Primate Platelets, J. C. Lewis, M. S. White, T. Prater, K. R. Porter, R. J. Steele
Scanning Electron Microscopy
The organization of cytoskeletal proteins in whole-mount adherent platelets from African green monkeys and normal human volunteers has been studied by SEM, high vacuum electron microscopy (HVEM) and conventional (120 kV) electron microscopy. We describe three distinct organizational zones, the Central Matrix, the Trabecular Zone and the Peripheral Web in spread platelets from both sources. The Central Matrix is an ill-defined superstructure of 80-100 Å filaments of short length which enshrouded the granules, dense bodies, mitochondria and elements of the open-channel and dense-tubular systems. The latter, identified through the use of peroxidase cytochemistry with the whole mounts, is an anastomosing …
Plasma Membrane Antigens Detected By Replica Techniques, H. Hohenberg, W. Bohn, G. Rutter, K. Mannweiler
Plasma Membrane Antigens Detected By Replica Techniques, H. Hohenberg, W. Bohn, G. Rutter, K. Mannweiler
Scanning Electron Microscopy
Methods are introduced for in situ preparation of cell cultures grown on glass coverslips using the replica technique. Special equipment and handling procedures enabled us to prepare large-sized and stable replicas suitable for ultrastructural and immunocytochemical analysis of the different faces of the plasma membrane (PM): the extraplasmic surface (ES), the complementary extraplasmic (EF) and protoplasmic (PF) fracture face, and the protoplasmic surface (PS). Colloidal gold markers in combination with protein A and monospecific/monoclonal antibodies were used to identify virus-specific antigens at the ES of infected cells. Stereo replicas show a coincident location of gold-labeled virus antigens at the ES …
Observation Of Colloidal Gold Labelled Platelet Surface Receptors And The Underlying Cytoskeleton Using High Voltage Electron Microscopy And Scanning Electron Microscopy, R. M. Albrecht, J. A. Oliver, J. C. Loftus
Observation Of Colloidal Gold Labelled Platelet Surface Receptors And The Underlying Cytoskeleton Using High Voltage Electron Microscopy And Scanning Electron Microscopy, R. M. Albrecht, J. A. Oliver, J. C. Loftus
Scanning Electron Microscopy
Fibrinogen conjugated to colloidal gold or colloidal gold-monoclonal anti-glycoprotein IIb/IIIa (fibrinogen receptor) was used to label the receptor on platelets. Whole mount preparations were examined by stereo pair high voltage electron microscopy and then by scanning electron microscopy to determine the feasibility of this approach in detecting the number of receptors and their location relative to the cytoskeletal and surface structure. Both the ligand-gold and antibody-gold labels were effective. The relative numbers of receptors could be seen and their relationship to cytoskeletal structure could be determined. Marked differences in receptor number and distribution were observed when platelets in different stages …