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Biomedical subjects

T Kushida

Publications and source records attributed to T Kushida.

At least 55 records · Page 3Linked to original sources
PubMed1987

Spectroscopic properties of fluorescein in living lymphocytes.

Detailed studies have been performed on various spectroscopic properties such as time dependence and excitation wavelength dependence of the fluorescence anisotropy for fluorescein molecules introduced into rat thymus lymphocytes. Experimental results have been found to be well interpreted in terms of the coexistence of two types of dye molecules, i.e., free and bound molecules. The fluorescence spectrum of only the bound molecules has been obtained from the difference in the time-resolved spectra of fluorescence with two polarization directions. The time gate has been set at a sufficiently late time after the excitation, so that the polarization memories of the free molecules are lost. The spectrum thus determined agrees very well with that calculated from the spectral data in the stationary condition. From the above results, we come to the conclusion that the main factors which determine the fluorescence anisotropy inside the cell are the fraction and the anisotropy of the bound dye molecules. Finally, we discuss how these factors are related to biological quantities.

Animals↗
PubMed1986

PAS staining of eosinophils in semi-thin sections of bone marrow embedded in glycol methacrylate.

The usual periodic acid-Schiff (PAS) reaction of glycosaminoglycans is applicable to paraffin embedded material. A modification for water-miscible methacrylate embedded tissue suitable for correlative light and electron microscopic studies, which makes it possible to find the same stained cell in a semi-thin tissue section, is described. Eosinophil leukocytes in semi-thin sections from bone marrow were verified by electron microscopy after staining with the PAS reaction. Immature eosinophil leukocyte granules reacted with and without previous salivary treatment. This method facilitates the search for localization of glycosaminoglycans in scattered blood cells.

Animals↗
PubMed1985

Localization of periodate-Schiff reactive glycosaminoglycans in semi-thin sections embedded in GMA-Quetol 523-MMA--application of a method for correlative light and electron microscopy of identical sites.

A correlative light and electron microscope method in which semi-thin sections of embedded tissue were treated with periodate acid and Schiff's reagent (PAS) was used to determine the precise localization of PAS reactive substance. Small blocks of tissue specimens were fixed with aldehyde mixtures. After dehydration, the blocks were embedded in a modified mixture of glycol methacrylate (GMA), Quetol 523, methyl methacrylate (MMA) and QCU-1. Semi-thin sections, 0.2-0.3 micron thick, were stained by the PAS reaction, followed by counterstaining with hematoxylin if necessary. It was found that PAS reaction products representing the specific sites for glycosaminoglycans and glycoproteins were seen in both light and electron microscopy. In the control experiments the specificity of the reaction was confirmed. The granules of goblet cells were well stained and contrasted by the reaction materials. The basement membrane and the microvilli of the epithelial cells appeared as the staining layer. In the spermatocytes the reaction products were demonstrated in the Golgi apparatus, acrosomal vesicles and head cap. The results indicated that the PAS deposits became electron dense when the embedding matrix had a low electron scattering property. Using this method of preparing semi-thin sections, a comparative study of the localization of glycosaminoglycans was performed.

Animals↗
PubMed1983

Observation on backscattered electron image (BEI) of a scanning electron microscope (SEM) in semi-thin sections prepared for light microscopy.

In order to examine semi-thin section for light microscopy with the backscattered electron mode (BE mode), identical sites in tissue sections were comparatively observed with both light microscopy and BE mode. Tissue blocks (ca. 3 X 3 X 1 mm) were fixed in glutaraldehyde or combined formaldehyde-glutaraldehyde solution. After dehydration in alcohol, they were embedded in Kushida's GMA-Quetol 523. 1.0 micron sections on glass slides coated with indium oxide were stained with hematoxylin-eosin or toluidine blue or by the Giemsa method, and then treated with osmium tetroxide vapor or aqueous KMnO4 solution or uranyl acetate-lead citrate solution. The identical places of such sections could be examined with the accelerating potential of 6 kV and the probe current of 8 X 10(-10) A using a JSM-35C SEM with BEIS BE detector. Photographs were taken with the 2500-line resolution cathode ray tube and the time of exposure was 100 sec. The sections were placed at a distance of 5mm from the BE detector. BE images from osmium tetroxide vapor staining showed a distinctly improved contrast especially when the sections were previously stained with hematoxylin and eosin. The cellular structure was clearly demonstrated under the electron microscope in the BE mode. Identical sites in tissue samples could be compared exactly with both light and electron micrographs.

Animals↗
PubMed1982

Light and electron microscopic observations of glycogen in semi-thin sections employing GMA, Quetol 523 and methylmethacrylate.

The use of improved GMA-Quetol 523 or GMA-Quetol 523 methyl methacrylate (MMA) mixture as an infiltration medium for the histochemical demonstration of glycogen has been devised to facilitate embedding, sectioning and staining. An improved method of infiltration uses such mixtures with a double weight of QCU-1 as a catalyst. Since the double weight of catalyst prevents interference by bleeding of picric acid from tissue blocks into the resin mixtures, improved mixtures penetrate readily and completely into the tissue fixed in picric acid-formaldehyde-glutaraldehyde solution (PAFG). PAFG solution has been found suitable for the histochemical fixation of glycogen in semithin sections. In hepatocytes specific reaction products appeared a deep reddish-purple after periodic oxidation and Schiff's reaction (PAS reaction), which was lost in previous digestion by means of salivary deastase. Glycogen can be identified as a PAS positive area in semi-thin sections 0.2-0.3 micrometers thick under the light microscope. Identical reactions sites of such sections show a high contrast in electron microscopy without any staining by either heavy metals or osmium tetraoxide vapor. It was therefore demonstrated that total glycogen produced after PAS reaction was revealed distinctly with deep contrast precipitates. This method provides significant morphological data for the histochemical localization of glycogen.

Acrylates↗