scholarly journals Application of Three-Dimensional Light Microscopy for Thick Specimen Studies

2016 ◽  
Vol 46 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Yeon Seung Rhyu ◽  
Se Jeong Lee ◽  
Dong Heui Kim ◽  
Chang-Sub Uhm
1999 ◽  
Vol 82 (08) ◽  
pp. 277-282 ◽  
Author(s):  
Yuri Veklich ◽  
Jean-Philippe Collet ◽  
Charles Francis ◽  
John W. Weisel

IntroductionMuch is known about the fibrinolytic system that converts fibrin-bound plasminogen to the active protease, plasmin, using plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator. Plasmin then cleaves fibrin at specific sites and generates soluble fragments, many of which have been characterized, providing the basis for a molecular model of the polypeptide chain degradation.1-3 Soluble degradation products of fibrin have also been characterized by transmission electron microscopy, yielding a model for their structure.4 Moreover, high resolution, three-dimensional structures of certain fibrinogen fragments has provided a wealth of information that may be useful in understanding how various proteins bind to fibrin and the overall process of fibrinolysis (Doolittle, this volume).5,6 Both the rate of fibrinolysis and the structures of soluble derivatives are determined in part by the fibrin network structure itself. Furthermore, the activation of plasminogen by t-PA is accelerated by the conversion of fibrinogen to fibrin, and this reaction is also affected by the structure of the fibrin. For example, clots made of thin fibers have a decreased rate of conversion of plasminogen to plasmin by t-PA, and they generally are lysed more slowly than clots composed of thick fibers.7-9 Under other conditions, however, clots made of thin fibers may be lysed more rapidly.10 In addition, fibrin clots composed of abnormally thin fibers formed from certain dysfibrinogens display decreased plasminogen binding and a lower rate of fibrinolysis.11-13 Therefore, our increasing knowledge of various dysfibrinogenemias will aid our understanding of mechanisms of fibrinolysis (Matsuda, this volume).14,15 To account for these diverse observations and more fully understand the molecular basis of fibrinolysis, more knowledge of the physical changes in the fibrin matrix that precede solubilization is required. In this report, we summarize recent experiments utilizing transmission and scanning electron microscopy and confocal light microscopy to provide information about the structural changes occurring in polymerized fibrin during fibrinolysis. Many of the results of these experiments were unexpected and suggest some aspects of potential molecular mechanisms of fibrinolysis, which will also be described here.


2020 ◽  
Vol 71 (10) ◽  
pp. 2898-2909
Author(s):  
Nathanaël Prunet ◽  
Keith Duncan

Abstract Developmental biology relies heavily on our ability to generate three-dimensional images of live biological specimens through time, and to map gene expression and hormone response in these specimens as they undergo development. The last two decades have seen an explosion of new bioimaging technologies that have pushed the limits of spatial and temporal resolution and provided biologists with invaluable new tools. However, plant tissues are difficult to image, and no single technology fits all purposes; choosing between many bioimaging techniques is not trivial. Here, we review modern light microscopy and computed projection tomography methods, their capabilities and limitations, and we discuss their current and potential applications to the study of flower development and fertilization.


Author(s):  
G. H. Morrison ◽  
M. G. Moran

Ion induced sputtering of materials can be used to generate images which contain morphological and chemical information. This method of image generation has several key advantages over other techniques. All elements can be detected and imaged. Discrimination among the various isotopes of the elements is possible with sufficiently high mass resolution. Analytical sensitivity is high for many elements, especially those of biological importance such as Na, K, Mg, Ca. The extension of these principles to imaging of molecular ion species is straightforward. Since the sputtering of the sample surface causes erosion, the distribution of elements as a function of depth can be investigated. Depth profiling, in conjunction with imaging is a powerful technique for solving problems of multielement microcharacterization of materials. This technique, which the authors have dubbed Image Depth Profiling, (IDP) also forms the basis for three dimensional reconstruction of elemental distributions within microvolumes of materials.In imaging ion microscopy, the image is acquired in a manner reminiscent of light microscopy. The analogy is depicted in figure 1. An energy homogeneous beam of primary ions irradiates the sample surface and sputtered secondary ions are focused directly on a microchannel ion to electron conversion plate. The primary ions are analogous to the illuminating photons of light microscopy and the secondary ions are analogous to the transmitted or reflected photons.


Author(s):  
James N. Turner ◽  
Donald H. Szarowski ◽  
Karen L. Smith ◽  
John W Swann

Thick slices of brain tissue are studied in vitro because neurons deep in the slice maintain physiologic contact with large numbers of other neurons, and are thought to function in a manner similar to that of in tact brain. The three-dimensional (3-D) morphology and electrophysiology of these cells can be studied and correlated. The confocal light microscope with its z-direction discrimination forms optical sections through the entire thickness of the slice, and stereo pairs or full 3-D reconstructions can be displayed using the optical sections as data sets. Individual neurons injected with fluorescent dyes or peroxidase based stains are imaged in either the fluorescent or reflection modes.


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