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Biomedical subjects

K Wake

Publications and source records attributed to K Wake.

At least 73 records · Page 4Linked to original sources
PubMed1987

Stellate cells storing retinol in the liver of adult lamprey, Lampetra japonica.

Distribution, localization and fine structure of the stellate cells in the liver of lamprey, Lampetra japonica, were studied during the spawning migration by use of Kupffer's gold-chloride method, fluorescence microscopy for vitamin A (retinol) and electron microscopy. The stellate cells in the lamprey liver differ in some of their properties from those in mammalian livers. Stellate cells which store abundant retinol in lipid droplets, occur not only in the hepatic parenchyma, but also in the dense perivascular and capsular connective tissue of the liver and in the interstitium of pancreatic tissue. In the hepatic parenchyma these cells are located perisinusoidally or along thick bundles of collagen fibrils. The stellate cells display a number of large retinol-containing lipid droplets, granular endoplasmic reticulum, tubular structures, dense bodies. Golgi complex, microtubules, and microfilaments. In the space of Disse, the stellate cells and extracellular fibrilar components such as collagen fibrils and microfibrils (11-12 nm in diameter) are intervened between the two layers of basal laminae. Differentiation and possible functions of the stellate cells in the lamprey liver are discussed.

Animals↗
PubMed1987

Structure and function of red cell cytoskeleton.

Red cell shape changed reversibly depending on the ATP level, but the volume did not change. The surface area of both lipid bilayer and cytoskeleton network changed depending on the ATP level. Mild trypsin treatment of ghosts dissipated only ankyrin band and abolished the shape-and viscosity-change induced by CPZ and ATP+warming. Triton shells losing permeability barrier shrunk on addition of small concentrations of Ca2+ and swelled again on further addition of MgATP. The shells dissociated in 0.1mM MgATP and reassociated in 0.15M KC1. The nucleotide specificity was high. From diameters of cells, ghosts and shells at different pH and others, we propose that the erythrocyte shape is primarily decided by the cytoskeleton, the role of the lipid bilayer is complementary and thirdly the shape is modified by the relative volume of the cytoplasma.

Cytoplasm↗
PubMed1986

Expression and rearrangement of the alpha, beta, and gamma chain genes of the T cell receptor in cloned murine large granular lymphocyte lines. No correlation with the cytotoxic spectrum.

Using cloned murine large granular lymphocyte (LGL) lines, the expression and the rearrangement of the alpha, beta, and gamma chain genes of the T cell receptor (TCR) were analyzed. Morphological, phenotypical, as well as functional studies indicated that the LGL lines were identical to normal, endogenous NK cells. Northern blot hybridization analysis indicated that the full-length transcripts of all the alpha, beta, and gamma chain genes were expressed in most of the LGL lines, including two lines derived from athymic nude mice. In one line, SPB, however, no transcript of the gamma chain gene was detected, whereas the alpha and beta chain genes were clearly expressed. In every LGL line studied, all of the alpha, beta, and gamma chain genes were rearranged. Conforming to the results of Northern blot hybridization study, the gamma chain gene of the SPB line was aberrantly rearranged, whereas those of all the other lines were productively rearranged. The results clearly revealed that NK cells represented a population of lymphocytes genetically committed to the T cell lineage. It was also suggested that the expression and rearrangement of the TCR genes of NK cells might occur in a thymus-independent fashion. An SPB line without expression of the gamma chain gene could exhibit NK activity indistinguishable from other NK lines. Furthermore, the rearrangement patterns of the beta chain gene did not correlate with the specificity of the cytotoxic activity. These results strongly suggested that the cytotoxic activity in NK cells was not directly mediated by TCR on them. We particularly noted that the beta chain gene of most independently established LGL lines showed identical patterns of rearrangement, indicating that they used the same V beta and J beta gene segments. The significance of the restricted pattern of rearrangement of the beta chain gene in LGL lines, as well as the possible functional roles of TCR on NK cells, was discussed.

Animals↗
PubMed1986

Conduction disturbance and tachyarrhythmia in postoperative ventricular septal defect and tetralogy of Fallot.

The importance of conduction disturbances and tachyarrhythmias as the determining factors of the late results of postoperative patients with ventricular septal defect and tetralogy of Fallot was reconfirmed in this follow-up study. It was found, however, that the incidences of complete heart block, bilateral bundle-branch block, and ventricular tachyarrhythmia have decreased significantly since the establishment of cold cardioplegia. This has certainly contributed to the remarkable improvement in late follow-up results of postoperative patients with ventricular septal defect or tetralogy of Fallot.

Arrhythmias, Cardiac↗
PubMed1986

Improved Kupffer's gold chloride method for demonstrating the stellate cells storing retinol (vitamin A) in the liver and extrahepatic organs of vertebrates.

This paper describes our modification of the classical gold chloride technique for the demonstration of the perisinusoidal stellate cells in the liver. The results of the method as introduced by von Kupffer (1876) are unpredictable. Using our modification, high quality gold preparations can be obtained. The method allows selective staining of retinol (vitamin A)-storing stellate cells in the liver and extrahepatic organs of various vertebrates. The sensitivity of the reaction is comparable to that of the fluorescence method for retinol. The technique is simple and the preparations keep for several years. Formol fixed specimens can be counterstained with Sudan III or hematoxylin. We have also developed a simple technique for making "sinusoid-net preparations," removing the parenchymal cells by supersonication. The clear visualization of the stellate cells that results has made it possible to study the distribution of these cells.

Animals↗
PubMed1986

Characteristic distribution density of organelles in the cytoplasm of respective kinds of cell lineages of ascidian embryos.

In the early embryos of the ascidian (Halocynthia roretzi), regional cytoplasmic differences arise just after fertilization. We successively studied the characteristic features of the cytoplasm of those regions in the embryonic cells during the entire ontogenic process from the unfertilized egg to the tadpole larva. The embryos and larvae were fixed in a mixture of osmium and glutaraldehyde, and the distribution of the organelles in the entire cytoplasm was observed with light and electron microscopy. According to the analysis of the distribution density of the organelles which occupied a given area of the cytoplasm on the section, we introduced the "organelle region" in the cytoplasm and further calculated the approximate area ratios of the "organelle regions" in the cytoplasm of each cell lineage. As a result, it was demonstrated that the characteristic distribution mode was already present in the cytoplasm of the cell lineages of the 8-cell-stage embryos. The features of the cytoplasm in each embryonic cell lineage, moreover, reflected those of the corresponding larval tissue. Our results not only demonstrate that the structural tissue specificity is expressed at an extremely early stage during the ascidian embryogenesis but also suggest that the corresponding functional differentiation among the cell lineages occurs early.

Animals↗
PubMed1986

Ultrastructural features of the cytoplasm of respective kinds of cell lineages of cleavage-arrested ascidian embryo.

We observed the ultrastructural features of the cytoplasm in the cell lineages of the cleavage-arrested embryos of the ascidian, Halocynthia roretzi, and compared them with those of the cytoplasm in the corresponding cell lineages of the normal embryos or in the corresponding tissues of the normal larva, in order to examine the presence or the degree of the cellular differentiation without the cleavage. The cleavage of the embryos was arrested by the cytochalasin B at the 16-cell and the embryos were cultured in sea water containing cytochalasin B until the developmental time equivalent to the hatching of the control larva. As a result, the cytoplasmic components in the cleavage-arrested 16-cell embryos resembled those observed in the corresponding tissues of the normal larvae, especially in the b5.3 and b5.4 blastomers (epidermal lineage cells) and in the B5.1 blastomeres (which give rise to the endodermal, mesenchymal and muscle cells) but they were less uniformly organized and their polarity or orientation was very random and irregular, compared with those in the normal larvae. These results demonstrated that the morphological differentiation similar to the larval tissue differentiation could proceed even in the cleavage-arrested embryos to a certain extent.

Acetylcholinesterase↗
PubMed1985

Pit cells in extrahepatic organs of the rat.

Electron microscopic examination of the extrahepatic distribution of pit cells, a cell type found in the liver, revealed their existence in several other organs of the rat. They were relatively frequent in lungs, spleen (red pulp), small intestine, epididymis, trachea, and peripheral blood; much fewer in bone marrow and thymus (medulla); and nonexistent in lymph nodes, spleen (white pulp), and thymus (cortex). The pit cells in these organs, as well as in the liver, contained characteristic dense granules and rod-cored vesicles in the cytoplasm. Our observations suggest that pit cells circulating in the peripheral blood adhere to the endothelium of capillaries in the various organs and migrate into the tissue, where they have some special immunological function.

Animals↗
PubMed1985

Modes of endocytosis of latex particles in sinusoidal endothelial and Kupffer cells of normal and perfused rat liver.

The endocytosis of latex particles (0.33, 0.46 and 0.80 micron in diameter) in the sinusoidal endothelial and Kupffer cells of the rat liver was studied electron microscopically. When the liver was perfused with serum-free oxygenated Krebs Ringer bicarbonate, latex particles of all three sizes were taken up by the endothelial cells. After a 10-min perfusion, particles were incorporated by the luminal cell surface of the perikarya or of the thick portion of the endothelial cells. A large patch of bristle coat was surrounding the ingested particle. The number of ingested particles in the endothelial cells, however, was much less than in the Kupffer cells. In in vivo experiments, no endocytosis of the latex particles was observed in the endothelial cells. In the Kupffer cells, particles were engulfed by the ruffled membranes or sank into the cytoplasm without a large patch of the bristle coat both in the perfusion system and in vivo. These observations show that at least 0.80 micron latex particles are taken up by the bristle-coated membranes in the sinusoidal endothelial cells of the perfused liver. The endocytic mechanism for latex particles in the endothelial cells is different from that of the Kupffer cells.

Animals↗
PubMed1985

Suppression of experimental hepatic fibrosis by administration of vitamin A.

The effect of vitamin A on experimental hepatic fibrosis in rats induced by administration of carbon tetrachloride (CCl4) and pig serum was studied. Vitamin A content in the CCl4-induced cirrhotic liver decreased significantly. Administration of pig serum caused hepatic fibrosis without hepatocytic damage. Vitamin A suppressed induction of experimental hepatic fibrosis by CCl4 and pig serum. Neither hepatocytic injury nor increased activities of serum aspartate aminotransferase and glutamic pyruvic transaminase induced by CCl4 was diminished by vitamin A. These data provide evidence that vitamin A inhibits hepatic fibrogenesis and that this effect may be mediated by an action on stellate cells rather than hepatocytes.

Animals↗
PubMed1984

Regressive post-hatching development of acetylcholinesterase-positive neurons in the pineal organs of Coturnix coturnix japonica and Gallus gallus.

Distribution and number of acetylcholinesterase-positive neurons were studied in the Japanese quail and the domestic fowl during the post-hatching period by means of the acetylcholinesterase method. For comparison, the development of the catecholamine-containing (sympathetic) pinealopetal fibers of the domestic fowl was demonstrated with the use of the glyoxylic acid method. The number of acetylcholinesterase-positive ganglion cells in the pineal organs of both avian species decreased rapidly after hatching, with a concentration of these elements in the basal portion (stalk) of the pineal organ. In 3-day-old chickens, perivascular catecholamine-containing nerve fibers penetrate the antero-lateral walls of the pineal organ and are found exclusively in the interfollicular and perivascular tissues. In 13-day-old and adult fowl, these fibers increase in number and terminate not only in the interfollicular space but also in the neuroepithelial parenchyma of the pineal body. The ontogenetic regression of the sensory structures paralleled by an expanding sympathetic innervation in the pineal organ of a galliform species resembles somewhat the process of phylogenetic transformation leading from pineal sense organs to pineal glands.

Acetylcholinesterase↗