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Biomedical subjects

Y Tashiro

Publications and source records attributed to Y Tashiro.

At least 199 records · Page 11Linked to original sources
PubMed1983

Intracellular forms of transferrin oligosaccharide chains in rat liver.

Glycosylation of transferrin was investigated in vivo by using antibody monospecific for rat serum transferrin. Pulse-chase experiments indicated that, after intravenous injection of [35S]methionine, labeled transferrin appeared in the rough and smooth microsomes and Golgi subfractions in rapid succession in 10 min and that an additional 10 min was required for it to be secreted. Most of the intracellular transferrin (95%) immunoprecipitated from the total microsome fraction was sensitive to endo-beta-N-acetylglucosaminidase H (endo H), whereas serum transferrin was completely resistant to it. Further fractionation of the total microsomes has revealed that the intracellular transferrin immunoprecipitated from the rough and smooth microsomes and GF3 are all endo-H-sensitive and most of the endo-H-sensitive oligosaccharides were eluted at the position corresponding to Man8GlcNAc on high-resolution Bio-Gel chromatography. This finding suggests that the major form of intracellular transferrin oligosaccharide in the course of intracellular transport from the endoplasmic reticulum to the Golgi apparatus is Man8GlcNAc2. Endo-H-resistant forms were first detected in the GF2 but more in GF1, most of which were sensitive to neuraminidase. Since the heavy Golgi subfraction contains mainly cis-Golgi elements, such as cisternae, and the light subfraction mainly trans-Golgi elements, such as secretory granules, it is strongly suggested that the processing of these large mannosyloligosaccharide chains and the subsequent addition of terminal sugars to them are performed successively in the trans-Golgi region just before secretion.

Animals↗
PubMed1983

Identification of calcium-independent myosin kinase with casein kinase II.

A crude myosin fraction from bovine brain has been found to contain a Ca2+-independent myosin kinase that catalyzes the phosphorylation of 20,000-Da light chain of gizzard myosin. The myosin kinase has been separated from the myosin by Sepharose CL-4B gel filtration and purified further by chromatography on phosphocellulose, Sephacryl S-300, and hydroxylapatite. The myosin kinase was found to copurify with casein kinase II and show the same substrate specificity with the casein kinase. These results indicate that the myosin kinase is identical to casein kinase II. The purified myosin kinase catalyzed the preferential phosphorylation of the threonyl residues of 20,000-Da light chains of gizzard and brain myosins. The 17,000-Da light chains of these myosins and the mixed light chains of skeletal and cardiac muscle myosins were not phosphorylated by the enzyme to an appreciable extent.

Amino Acids↗
PubMed1983

Isolation of the alpha and beta subunits of canine (Na+,K+)ATPase by using SDS-PAGE and lectin-Sepharose.

(Na+,K+)ATPase from dog kidney was solubilized and denatured by SDS treatment, then applied to a Con A- and WGA-Sepharose column. While the alpha subunit of the ATPase had no affinity for either of the lectin-Sepharoses, the beta subunit specifically bound to WGA-Sepharose and was eluted with N-acetylglucosamine. This property was utilized for the isolation of the alpha and beta subunits by using lectin-Sepharoses and SDS-polyacrylamide gel electrophoresis. The amino acid composition of the alpha subunit thus isolated was in reasonable agreement with the data reported by Kyte (Kyte, J. (1972) J. Biol. Chem. 247, 7642-7649). The amino acid and carbohydrate compositions of the beta subunit were, however, different from his data. The beta subunit contained little histidine (0.1 mol/100 mol amino acid) and a very large amount of carbohydrates (33%). The antibody raised against alpha or beta subunit reacted specifically with the corresponding subunit and with protease-fragmented alpha subunit and neuraminidase-treated beta subunit, respectively, but no cross-reactivity was observed between the two subunits. These results indicate that our alpha and beta subunits were highly purified.

Amino Acids↗
PubMed1983

Immunoelectron microscopy of the outer membrane of rat hepatocyte nuclear envelopes in relation to the rough endoplasmic reticulum.

Prefixed nuclei were isolated from rat liver after perfusion with dilute glutaraldehyde. These nuclei sometimes were associated with the rough endoplasmic reticulum (ER), and occasionally continuity of the outer nuclear membrane with rough ER membrane was found. When these prefixed nuclei were incubated with ferritin antibody conjugates against cytochrome P-450, the cytoplasmic face of the outer nuclear membrane was labeled with ferritin similar to the labeling of the rough ER membrane. In the nuclear pore region, ferritin particles were present on the outer membrane up to the outer annuli of the pore complexes. When unfixed nuclei were incubated at 0-4 degrees C or at 20 degrees C, some outer nuclear membranes were detached from the nuclear surface. In this case the nuclear pore complexes remained associated with the inner nuclear membrane, and small inside-out vesicles were formed at these pore regions. We also found some rough vesicles heavily labeled with ferritin particles within the nuclear matrix. They probably were derived from the rough ER or from the outer nuclear envelope which was internalized artificially during incubation.

Animals↗
PubMed1983

Subcellular compartments and protein topogenesis.

A cell is surrounded by a plasma membrane. It contains various organelles, most of which are enclosed by limiting membranes. The intracellular space is thus divided into a number of subcellular compartments. Structurally, a cell is composed of membranes and the spaces enclosed by those membranes. In order to classify these compartments, the extracellular space has been designated S1 and whenever a unit membrane structure is crossed to arrive at the next space, one is added to term; the cytoplasmic space becomes S2, the intraluminal space of the endoplasmic reticulum and the intermembrane space of the mitochondria S3, and the matrix space of the mitochondria S4. Similarly, the plasma membrane is M1, the outer membrane of the mitochondria M2, and the inner counterpart M3. This classification of the subcellular compartments is useful in understanding a number of complicated cellular structures and functions. The intracellular transport of newly synthesized protein (protein topogenesis) and the probable development of subcellular organelles during phylogenesis of eukaryotic cells is discussed in terms of these subcellular compartments.

Bacteria↗
PubMed1983

Experimental phospholipidosis induced by 4,4'-diethyl-aminoethoxyhexestrol. Morphological and biochemical interpretations.

The effect of a generalized phospholipidosis inducing drug, diethylamino-ethoxyhexestrol (DH, a coronary vasodilator), was studied using rats. The initial alterations are characterized by the appearance of abnormal cytoplasmic inclusion bodies. At the early stage of DH administration, they appeared near the Golgi apparatus. Histochemical and ultrastructural evidence showed that the inclusion bodies consisted of polar lipid, mainly of phospholipids. From cytochemical and biochemical observation, the lysosome was regarded as the primary site of the drug-induced morphological changes. The drug-induced abnormal cytoplasmic inclusion bodies were of three basic morphological types, i.e., multilamellated, crystalloid and finger-print-like bodies. Additionally, many intermediate forms were found showing structural features of those basic types. These drug-induced cytoplasmic changes, namely storage of phospholipids, were considered to be reversible both morphologically and biochemically after the cessation of DH administration.

Animals↗
PubMed1983

Isolation and some properties of a new binding protein for asialoorosomucoid from rat liver.

Binding proteins for asialoorosomucoid were prepared from rat liver previously labeled in vivo with [3H]leucine by affinity chromatography on asialoorosomucoid-Sepharose 4B. They were subjected again to the same affinity chromatography and eluted into two fractions successively with 10 mM Tris-HCl buffer, pH 7.8, containing 1.25 M NaCl, 1% Triton X-100 and 50 mM lactose and 20 mM ammonium acetate buffer, pH 6.0, containing 1.25 M NaCl and 1% Triton X-100, and designated as ABP-I and ABP-II (asialoorosomucoid binding proteins), respectively. ABP-I corresponds to the receptor protein specific for asialoglycoproteins which has been extensively investigated by Ashwell and collaborators (J. Biol. Chem. 254, 1038-1043, 1979). ABP-II is different from ABP-I in several properties such as molecular weight, antigenicity and solubility. The molecular weight of ABP-II was estimated to be 29,000 by SDS-PAGE. On gel filtration it behaved as a pentamer with an apparent molecular weight of 150,000. Unlike ABP-I, ABP-II showed no detectable binding activity when assayed according to the procedures of Hudgin et al. (J. Biol. Chem. 249, 5536-5543, 1974). The calcium ion was, however, essential for the binding of ABP-II to asialoorosomucoid-Sepharose 4B similar to ABP-I. ABP-II can be extracted from the total microsomes of rat liver in 1.0 M NaCl by sonication after freezing and thawing. This suggests that ABP-II is either a soluble protein or a peripheral membrane protein loosely attached to the intracisternal cavities of the microsomal membranes.

Animals↗
PubMed1983

[Case of epithelioid sarcoma of the lower extremity].

A 26-year-old woman with epithelioid sarcoma is reported. An 8 X 4 cm mass was present in the pretibial region of the right leg. The operative specimen revealed a solid mass with necrosis and hemorrhage. Histologically, the tumor consisted of large round or oval cells with rich and eosinophilic cytoplasm and many vascular invasions. Electron-microscopically, the tumor was composed of light and dark cells. The dark cells showed abundant microfibrils in their cytoplasm compared to the light cells. We posit that the tumor was of synovial cell origin because of the presence of cytoplasmic microfibrils, pinocytotic vesicles and filopodias or microvilli-like structures.

Adult↗
PubMed1983

[Carcinoma of the esophagus engrafted on corrosive stricture of the esophagus].

A highly significant incidence of esophageal cancer engrafted on corrosive stricture of the esophagus has been statistically evaluated. So far, only 8 cases in Japan and over 100 cases in foreign literatures have been reported. In 1976, we reported the first case of carcinoma of the esophagus associated with corrosive stricture of the esophagus in Japan. Our second case operated in 1975 was pathologically confirmed to be adenosquamous carcinoma of the esophagus which has never been reported in the literatures. In this paper surgical and pathological problems of the carcinoma of the esophagus associated with corrosive stricture of the esophagus were discussed adding to the analysis of 8 reported cases in Japan.

Aged↗
PubMed1982

Distribution of an asialoglycoprotein receptor on rat hepatocyte cell surface.

Direct ferritin immunoelectron microscopy was applied to visualize the distribution of the hepatocyte cell surface of the asialoglycoprotein receptor which is responsible for the rapid clearance of serum glycoproteins and lysosomal catabolism. For this purpose, rabbit antibody against the purified hepatic binding protein specific for asialoglycoproteins was prepared and coupled to ferritin by glutaraldehyde. The specific antibody conjugates were incubated with the hepatocytes, which were isolated from rat liver homogenate after fixation by glutaraldehyde perfusion. These cells preserved well the original polygonal shape and polarity, and it was easy to identify the sinusoidal, lateral, and bile canalicular faces. The surface density of the ferritin particles bound to the sinusoidal face was about four times higher than that of particles bound to the lateral face, while the bile canalicular face was hardly labeled and almost at the control level. Using the surface area of hepatocyte measured by morphometrical analyses, it was estimated that approximately 90% of bound ferritin particles were at the sinusoidal face, approximately 10% at the lateral face, and approximately 1% at the bile canalicular face. Nonhepatic cells such as endothelial and Kupffer cells had no receptor specific for asialoglycoproteins.

Animals↗
PubMed1982

Systemic lupus erythematosus associated with multiple nodular hyperplasia of the liver.

Three autopsy cases of systemic lupus erythematosus with unique association of multiple nodular hyperplasia (MNH) of the liver, portal hypertension, and hypertensive pulmonary vascular disease are reported. None of the patients had received oral contraceptive or androgenic steroid, but they were treated with glucocorticoids for 2 to 11 years. Raynaud's phenomenon, sclerodactyly, and mild impairment of the kidney were the common clinical features. Macroscopically, MNH is characterized by many nodules scattered throughout the non-cirrhotic liver, and histologically, each nodule is made up of normal-appearing hepatocytes and not encapsulated. Portal tracts are scanty in the nodules. MNH seems to be a regenerative-hyperplastic process, but its true nature still remains unclear. Relationships between MNH and portal hypertension, MNH and pulmonary hypertension, and collagen disease and pulmonary hypertension are discussed. A brief review of the literature concerning multiple benign hepatocellular tumors similar to MNH is also presented.

Adolescent↗
PubMed1981

Distribution and induction of cytochrome P-450 in rat liver nuclear envelope.

Induction of cytochrome P-450s by 3-methylcholanthrene (MC) and phenobarbital (PB) and distribution of P-450s in the rat liver nuclear envelope were investigated by biochemical analyses and ferritin immunoelectron microscopy using specific antibodies against the major molecular species of MC- and PB-induced cytochrome P-450. It was found, in agreement with Kasper (J. Biol. Chem., 1971, 246: 577-581), that the total amount of cytochrome P-450s determined by biochemical analysis was markedly increased by MC, but not by PB, treatment. Immunoelectron microscopic analysis, however, showed marked and slight increases in ferritin labeling by MC and PB treatment, respectively. The latter finding was interpreted as resulting from the induction of a particular molecular species of PB-induced cytochrome P-450s. Ferritin immunoelectron microscopic analysis of intact isolated nuclei, naked nuclei from which the outer membrane of the nuclear envelope was partially detached (mechanically), and isolated nuclear envelopes have shown that the ferritin particles are found exclusively on the cytoplasmic face of the outer nuclear envelopes. Neither the nucleoplasmic face of the inner membrane of the nuclear envelope nor the cisternal face of both membranes of the nuclear envelope showed any labeling with ferritin. This indicates that cytochrome P-450 is located only on the outer membrane of the nuclear envelope and does not diffuse laterally into the domain of the inner membrane of the nuclear envelope across the nuclear pores. Our results suggest that a marked heterogeneity exists in the enzyme distribution between the outer and inner membrane of the nuclear envelope and that microsomal marker enzymes such as cytochrome P-450 exist exclusively in the outer membrane. In addition, it appears that cytochrome P-450 is probably not a transmembrane protein but an intrinsic protein located on the cytoplasmic face of the outer membrane of the nuclear envelope.

Animals↗