Biomedical subjects
Publications and source records attributed to G H Cousineau.
It is suggested that the use of Hanks' + pipes + sucrose buffers, in combination with glutaraldehyde and osmium tetroxide fixatives, represent an excellent mode of preparation of fresh and cultured peripheral blood leucocytes, not only for transmission electron microscopy observation of these cells but also for scanning electron microscopy.
Normal human leucocytes, successively treated with glutaraldehyde-tannic acid-osmium tetroxide-thiocarbohydrazide-osmium tetroxide-thiocarbohydrazide-osmium tetroxide, were prepared for scanning electron microscopy observation. These cells produced well-contrasted, non-charging scanning images compatible with metal-evaporated material. Further, the mononuclear and polymorphonuclear cells resisted shrinkage during dehydration and critical point drying, thus allowing much improved images at high magnification than those covered with evaporated metal. In all cases at least a second thiocarbohydrazide-osmium tetroxide treatment could not be avoided.
SEM observation of acute myeloblastic leukemia cells, incubated for 20 h with the mitogens pokeweed and phytohaemagglutinin, showed these to have elongated structures that were either smooth or partially covered by thumblike figures. By contrast, the chronic lymphocytic leukemia cells possessed more compact shapes and some were covered with blebs of varying sizes.
Leucocytes were isolated from the peripheral blood of normal individuals and prepared for SEM observation. The addition of the buffer Hanks and Hepes to the glutaraldehyde fixative was found to maintain the initial ambient pH throughout cell manipulation, and to allow satisfactory preservation of surface architecture.
A study is presented of various buffers utilized in the preparation of human lymphocytes for scanning electron microscopy. Of nineteen different buffers tested, Hanks' balanced salt solution +0.04 mol sucrose appeared most adequate for satisfactory preservation of lymphocyte surface architecture.
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Variations in the mode of preparation, type of fixation and leukocyte collection can plan an important part in the determination of the surface structure of a given population, and can result in modifications of the microprojections, and their number, evident on the cell surface. We present preparatory modes that circumvent these difficulties, and the results obtained clearly show that the techniques are profitable, appear essential for the preservation of cell population and integrity, and allow accurate scanning electron microscopy observations without resort to time consuming procedures. Indeed, the entire process can be completed in one day.
The fine structure os Strongylocentrotus purpuratis testes has been examined. No obviously important differences appear to exist between the description reported here and the published fine structure of testes obtained from other sources. The most useful fixative was found to be a mixture of glutaraldehyde-paraformaldehyde.
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The fine structure of Tripneustes esculentus eggs was studied with the aid of an electron microscope. Cells obtained from this West Indies sea urchin showed cortical granules, mitochondria forming a rosette around lipid granules, endoplasmic reticula, Golgi apparatus and annulated lamellae. These structures appear identical to those seen in eggs of the Atlantic sea urchin: Arbacia punctulata.
Fractionation of total RNA prepared from intersterile wild type strains of Ascobolus immersus revealed the existence of differences at the 4S and 5S levels which may be related to the polymorphism of these species or sub-species, bearing the same name and coasting along in nature.
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This work shows the existence of differences in RNA profiles as obtained from blood cells of two LSD-affected persons. These had received slightly different concentrations of LSD yet their RNA profiles between them, and those of control patients, are remarkably different, especially regarding the 4S peaks. Further work is now being done in our laboratory in order to understand the meaning of these important differences.
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Explore the source record for details and available documents.