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Biomedical subjects

I Yoshioka

Publications and source records attributed to I Yoshioka.

At least 55 records · Page 3Linked to original sources

Effects of arildone on the immunogenicity of formalin-inactivated polioviruses.

Concentrated and purified Sabin and virulent strains of poliovirus types 1, 2 and 3 were inactivated with formalin at 37 C. By addition of 5.4 microM arildone, an antiviral agent, to the virus suspension, the stability of D antigen increased in both Sabin and virulent strains of all types, especially in virulent type 1 Mahoney strain. The drug had neither any inhibitory nor enhancing effect on the formalin inactivation. When antibody response was compared in guinea pigs, Sabin strains inactivated in the absence of arildone were less immunogenic against homotypic virulent strains than inactivated vaccine prepared from virulent strains. On the other hand, Sabin strains inactivated in the presence of arildone were equally immunogenic. These results indicate that it is possible to prepare from Sabin strains a potent and safe inactivated vaccine having an immunogenicity comparable to that prepared from virulent strains.

Animals↗

New observations on the fine structure of the normal nasopharyngeal epithelium of the mouse.

The ciliated columnar epithelium in the mouse nasopharynx was studied by use of light and electron microscopes. The ciliated cells were divided into 3 types because of the variability in electron density of the ground cytoplasm. The dark ciliated cells were characterized by well-developed rough endoplasmic reticulum and rod-shaped mitochondria with regular arrangements of pronounced cristae. In the light ciliated cells endoplasmic reticulum was poorly developed and mitochondria were vacuolated with irregular arrangements of cristae. Furthermore, there existed the "medium ciliated cells," termed by the authors, of which the cytoplasm was medium in electron density between the dark and the light ciliated cells, and some mitochondria were rod-shaped and others were vacuolated. The medium ciliated cells are regarded to be at a stage of transformation from the dark ciliated cells to the light ones. These findings suggest that the dark ciliated cells swell to decrease their electron density with declining activity, and finally transform into the light ciliated cells. The cells, termed the "potential ciliated cells" by the authors, were scattered between the ciliated cells, reached the lumen and had no cilia. They contained many procentrioles suggesting ciliogenesis and had a cytoplasm of the same electron density as that of the dark ciliated cells. It is considered that the dark ciliated cells originate from the potential ciliated cells.

Animals↗

Three-dimensional and surface structures of rat filiform papillae.

The three-dimensional and surface structures of the simple conical papillae of the rat tongue have been demonstrated with scanning electron microscopy. The papillary projection was organized into the anterior, posterior and central core cell populations, whereas the basal region of the papilla which consisted of circularly arranged cells showed no differentiation into three autonomic cell populations. It is considered that the anterior and posterior cell populations around the central core tend to be mutually attached at the bilateral sides, and that the posterior and core cell contacts are rather close than the anterior one. The anterior papillary cells showed relatively smooth surface with little micropits and without microridges. The reticular microridges on the basal cell surface of the posterior papillary cells appear to later develop the micropits and linear microridges on the tip cell surface. These suggest that the anterior cell surface is more highly keratinized than the posterior one. The microridges or micropits on the outer cell surface and the microprojections on the inner cell surface organizing filiform papilla are considered to be the structures for the purpose of cell adhesion.

Animals↗

Plaque assay of equine influenza virus.

ESK cells, a stable cell line derived from a swine embryo kidney, were found to be a good medium for plaque formation of the Prague and Miami strains of equine influenza virus. Factors influencing the plaque formation were investigated and a plaque assay for these viruses was worked out. The method is not only simple enough for routine use, but also is as sensitive as the egg inoculation method. The method was readily adapted for a neutralization test.

Animals↗

Characterization of ribonucleic acid transcriptase in Ibaraki virus core particles.

Ibaraki virus core particles were purified from infected BHK-21 cells. The core particles displayed RNA transcriptase activity while the virion did not. The RNA transcriptase activity was stimulated about 15-fold by addition of S-adenosyl-L-methionine. The reaction product was single-stranded RNA which could be hybridized with heat-denatured Ibaraki virus RNA. The hybrids possessed the same electrophoretic mobility as Ibaraki virus double-stranded RNA.

Animals↗

Taste bud papillae on the retromolar mucosa of the rat, mouse and golden hamster.

The retromolar mucosa of the rat, mouse and golden hamster was observed by light and scanning electron microscopy. Numerous taste bud papillae, each of which formed a low round eminence containing one to several taste buds, were present in the posterior region of the retromolar mucosa, and were especially concentrated in the vicinity of the orifices of the molar glands. This topographical coincidence suggests that the retromolar mucosa of these animals has a functional role as a taste organ. Microridges, arranged in various patterns and small pits, were observed on the surface of the keratinized epithelium of the rat and mouse retromolar mucosa. It appears that the development of numerous microridges is adapted for varied stimuli in the oral cavity.

Animals↗

Comparative measurement of equine influenza virus antibodies in horse sera by single radial hemolysis, neutralization, and hemagglutination inhibition tests.

Single radial hemolysis (SRH), neutralization (NT), and hemagglutination inhibition (HI) tests were carried out on sera from horses immunized against the Prague and Miami strains of equine influenza virus. The HI and NT tests demonstrated good sensitivity; the sensitivity of the SRH test was somewhat lower. The NT titers of individual sera were correlated very closely with the HI titers, although the NT titers were higher. SRH zone diameters of individual sera also showed significant correlation with the NT and NI titers. The SRH test appears to be suitable for large-scale serological surveys and offers the advantages of rapidity and simplicity.

Animals↗

Fine structure of the fully keratinized hair cuticle in the head hair of the human.

The cuticle is composed of five cell layers in the cross section of the hair at a level of 100 mm above the scalp. Intercellular junctions between two cuticular cells are zonulae occludentes (tight junction); they consist of five layers. The gap junctions of the intercellular communications occur near the cortex. The trichohyalin granule appears in the cuticular cells of completely cornified head hair. The granule is generally smaller than that of the keratohyalin granule, and spherical in shape. The granule is not visible in the area near the surface of the hair. The keratin in the cytoplasm of the cuticular cell may originate from the trichohyalin granule.

Adult↗