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Y Bando

Publications and source records attributed to Y Bando.

At least 37 records · Page 2Linked to original sources
PubMed1990

Enhanced efficiency of cell hybridization by neuraminidase treatment.

Cell hybridization techniques have already been utilized, but the outcome is usually not very stable. In order to achieve high stability we tried to achieve closer intercellular contact. Neuraminidase treatment was used to remove sialic acid from the cell membrane, since sialic acid usually prevents close contact between B cells and myeloma cells. After neuraminidase treatment, not only mouse-mouse hybridization but also human-mouse hybridization produced significantly more clones. Our results indicate that neuraminidase treatment is a useful method for generating hybridomas efficiently.

Animals↗
PubMed1990

Superoxide-mediated release of iron from ferritin by some flavoenzymes.

NADH-lipoamide dehydrogenase mobilized iron from ferritin under aerobic conditions. Superoxide dismutase strongly inhibited this mobilization, indicating that the superoxide radical is generated by the enzymatic reaction and release iron from ferritin. Addition of lipoamide as an electron acceptor to NADH-lipoamide dehydrogenase increased the release of iron from ferritin and this release was partially inhibited by superoxide dismutase. Similarly, addition of menadione (2-methyl-1, 4-naphthoquinone) as an electron acceptor to xanthine-xanthine oxidase promoted the release of iron from ferritin and this release was strongly inhibited by superoxide dismutase. These results suggest that dihydrolipoamide and semiquinone of menadione can react with oxygen to form the superoxide radical that mediates release of iron from ferritin.

Animals↗
PubMed1989

Lens protein glycation and the subsequent degree of opacity in streptozotocin-diabetic rats.

We measured how much glycated protein there was in rat eye lenses with different degrees of cataract, using an antibody against glucitol-lysine. Streptozotocin-diabetic (STZ) rats were in some cases treated with insulin (STZ + INS); control rats were normal. We graded the cataracts from 0 (transparent) to 3 (entirely opaque). STZ rats had significantly more grade 3 cataracts, and STZ + INS rats more grade 1 cataracts, than other groups. Grade 3 lenses had significantly more glycated protein than those of grade 0 (10.8 +/- 2.7 vs. 1.0 +/- 0.4 nmol/mg protein), grades 1 and 2 being intermediate. Glycosylated hemoglobin levels correlated similarly with severity of cataract. These data are consistent with the greater incidence of cataract among diabetics than among non-diabetics, and suggest that lens protein glycation contributes to the development of cataract.

Animals↗
PubMed1989

[Analysis of P-glycoprotein in patients with acute leukemias by flow cytometry].

The identification of a P-glycoprotein product of multidrug-resistant gene (mdr 1) was reported recently. To examine the expression of the P-glycoprotein in acute leukemias of various types, we have prepared leukemic blast cells from patients and measured their positivity of P-glycoprotein using monoclonal anti-P-glycoprotein antibody (C219) by flow cytometry. P-glycoprotein is expressed in 8 out of 44 cases including leukemic blast cells but not lymphocytes and monocytes. In these cases showed drug resistance was shown clinically. In addition, the expression of the P-glycoprotein was not observed in the drug-sensitive cases and at the time of initial chemotherapy. Our results suggest that measurement of P-glycoprotein in acute leukemias by flow cytometry may prove to be a valuable tool for the design of chemotherapy protocols.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1989

[Expression of P-glycoprotein (multidrug-resistance gene product) in haematological tumors].

The fact that cancer cell acquires multidrug resistance to carcinostatics at cancer treatment is a very important subject clinically. The mode of multidrug-resistance is complicated, but the gene associated with multidrug resistance (MDR 1) has been isolated. It has become evident that MDR 1 gene carries membrane glycoprotein (P-glycoprotein) which occurs in the cell acquired drug-resistance. Assessment has been made this time regarding the occurrence of P-glycoprotein in the tumorous cells and tissues by the use of monoclonal antibody (C 219) to P-glycoprotein. Occurrence of P-glycoprotein in malignant lymphoma exhibited positivity in 9 cases out of 36 immunohistologically. 170 KD P-glycoprotein was detected in 4 cases out of 10 at Western blotting analysis of the protein isolated from the nuclear cell in the peripheral blood in the patients with leukemia. Further, P-glycoprotein positive cases were all progressive cases clinically and showed resistance to treatment. From these results, it has been clarified that occurrence of P-glycoprotein in haematological tumors is related to multidrug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1989

[The dynamics of leucocytes and complements in endotoxin induced uveitis].

The dynamics of leukocytes, complement and tumor necrosis factor (TNF) were studied in endotoxin induced uveitis (EIU) in rats. Endotoxin was administered to footpads and the time courses of the following were examined: 1) the number of leukocytes in peripheral blood 2) the number of leukocytes and protein concentration of aqueous humor 3) complement (CH50, C1, C3, C5) in serum and aqueous humor 4) TNF in serum 5) histological changes in the eyes, lungs, liver, and skin. The number of leukocytes in peripheral blood decreased to one third that of controls during three to six hours after endotoxin administration, but increased thereafter along with the number of leukocytes and protein concentration in aqueous humor. More leukocytes were observed than in controls in the small vessels of the iris, lung, liver and skin, some of which attached to the vascular endothelium. Serum C3 increased and serum C5 transiently decreased after endotoxin administration. Serum TNF reached a peak (3500 IU/ml) at 1.5 hours and rapidly decreased subsequently. It is suggested that the adhesion of leukocytes to vascular endothelium and the activation of complement system may play important roles in the development of EIU.

Animals↗
PubMed1988

Degradation of epidermal growth factor receptors by cathepsin L-like protease: inhibition of the degradation by c-Ha-ras gene products.

Extract of NIH3T3 mouse fibroblasts contains a protease which can cleave epidermal growth factor receptor (EGF receptor). This protease was tentatively named cathepsin X and purified to near homogeneity. The characteristics of cathepsin X were similar to those of cathepsin L and the proteolytic activity of cathepsin X was inhibited by c-Ha-ras gene products.

Animals↗
PubMed1988

Inhibition of cathepsin L-induced degradation of epidermal growth factor receptors by c-Ha-ras gene products.

The inhibitory activities of c-Ha-ras gene products (p21s) toward several cysteine proteinases have been investigated. The activity of cathepsin L was inhibited by p21s most effectively while those of cathepsin B and papain were slightly inhibited by p21s. p21s did not show any inhibitory activity toward cathepsin H. In order to connect the protease-inhibitor activity of p21s with cell growth, the degradation of epidermal growth factor receptors (EGF-receptors) was investigated. EGF-receptors were preferentially cleaved by cathepsin L but not by cathepsin B or H. The cleavage of EGF-receptors by cathepsin L was inhibited by p21s dose-dependently. These results raise the possibility that p21s can suppress the degradation of growth-related proteins such as EGF-receptors and thereby affect cell growth.

Carcinoma, Squamous Cell↗
PubMed1987

Autodegradation of lysosomal cysteine proteinases.

Repeated injections of Ep-475, a potent cysteine proteinase inhibitor, into rats caused several-fold increase in the hepatic contents of the lysosomal cysteine proteinases cathepsin B, H and L and in the activities of other lysosomal hydrolases. The rates of degradation of these lysosomal enzymes, estimated by repeated injections of cycloheximide, were found to be retarded in Ep475-treated rats, indicating that lysosomal cysteine proteinases are involved in degradation of lysosomal enzymes including proteinases.

Animals↗
PubMed1986

Purification and tissue distribution of rat cathepsin L.

Cathepsin L was purified to apparent homogeneity from rat kidney. The molecular weight of the enzyme was estimated to be 30,000, but part of the enzyme was found to consist of two polypeptide chains of Mr 25,000 and 5,000. Antibody against rat kidney cathepsin L did not cross-react with rat cathepsin B or H and detected only cathepsin L in crude rat tissue preparations on immunoblotted sheets. The concentrations of cathepsin L in various rat tissues and peripheral blood cells of rats were determined by a sensitive immunoassay, in which the minimum detectable amount of cathepsin L was 20 pg/assay. The concentration of cathepsin L was found to be highest in the kidneys, where it was more than 3 times higher than in the liver, spleen, lungs, and brain. Nervous tissues, especially the cerebellar cortex, also contained fairly high concentrations of cathepsin L, but the heart, skeletal muscle, and gastrointestinal tract contained low concentrations, as did peripheral blood cells. The cathepsin L content of macrophages was 20% of that of cathepsin B. The concentrations of cathepsin L in lymphocytes, neutrophils, and erythrocytes were 10%, 20%, and less than 0.2%, respectively, of those in resident macrophages.

Animals↗
PubMed1985

A new function of kininogens as thiol-proteinase inhibitors: inhibition of papain and cathepsins B, H and L by bovine, rat and human plasma kininogens.

The amidolytic activities of papain and rat liver cathepsins B, H and L were strongly inhibited by high (HMM) and low (LMM) molecular mass kininogens from bovine, human and rat plasmas, and their Ki values were estimated to be in the order of 10(-10) - 10(-11)M for papain and 10(-8) - 10(-9)M for cathepsins. The derivatives of bovine kininogens, HMM kinin-free protein, HMM kinin- and fragment 1 X 2-free protein, and LMM kinin-free protein also showed strong inhibitory activity toward these thiol-proteinases. These results suggest that a reactive site which interacts with thiol-proteinases is contained in the heavy chain portion in kininogens.

Animals↗
PubMed1985

Distribution of cathepsins B and H in rat tissues and peripheral blood cells.

The concentrations of cathepsins B and H in various tissues and peripheral blood cells of rats were determined by means of sensitive immunoassays. The minimum detectable amounts of cathepsins B and H were 30 pg and 20 pg/assay, respectively, and the presence of endogenous thiol proteinase inhibitors did not interfere with the immunoassays. Cathepsin B was found at high levels in the kidney, vagina, spleen, and adrenal gland, and cathepsin H at high levels in the kidney, vagina, liver, lung, and spleen. Low levels of cathepsins B and H were present in the heart, skeletal muscle, and testis. The ratios of cathepsins B and H in various organs were different: the brain and adrenal gland contained much higher levels of cathepsin B than of cathepsin H, whereas the lung and liver contained higher levels of cathepsin H than of cathepsin B. In several organs such as the kidney, spleen, liver, and lungs, the level of cathepsins B plus H was much higher than that of thiol proteinase inhibitors (TPI-alpha + TPI-beta), whereas in tissues containing large amounts of TPI-alpha, such as the skin, esophagus and stomach, the level of inhibitors was higher than that of cathepsins B plus H. Of the peripheral blood cells tested, macrophages had the highest contents of cathepsins B and H, and so their level of cathepsins B plus H was much higher than that of TPI-alpha plus TPI-beta, whereas lymphocytes and neutrophils contained comparable amounts of proteinases and inhibitors.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Different immunolocalizations of cathepsins B, H, and L in the liver.

Different localizations of cathepsin B, H, and L in normal rat liver were revealed immunohistochemically with anticathepsin Fab'-horseradish peroxidase conjugates. Staining of cathepsin B was strong in the periportal sinusoids, possibly in Kupffer cells; and weaker in panlobular hepatocytes. Staining of cathepsin H was strong in panlobular hepatocytes, especially in the periphery of the cytoplasm, possibly representing the peribiliary dense bodies; and weaker in periportal sinusoidal cells, possibly Kupffer cells. Staining of cathepsin L was strongest in centrilobular hepatocytes and weaker in periportal sinusoidal cells, possibly Kupffer cells. These findings, revealed for the first time in the present study, show that the histologic and intracellular localizations of the three cathepsins are different, suggesting that they have different roles in degradation of exogenous and endogenous proteins.

Animals↗
PubMed1984

Amino acid sequence of rat epidermal thiol proteinase inhibitor.

The complete amino acid sequence of rat epidermal thiol proteinase inhibitor was determined. The unique 103-residue sequence was derived by analysis of two peptides generated by limited proteolysis of the native inhibitor with Staphylococcus aureus V8 protease and of three cyanogen bromide fragments. The protein has a high degree of sequence homology to either rat liver or human leucocyte inhibitor but is not identical and may represent a new type of low molecular weight thiol proteinase inhibitors.

Amino Acid Sequence↗