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S Ohkuma

Publications and source records attributed to S Ohkuma.

At least 145 records · Page 8Linked to original sources
PubMed1990

[Separation of Thomsen-Friedenreich (T) antigen and N antigen precursor glycoproteins from perchloric acid-soluble fraction of cyst fluid of human ovarian clear cell carcinoma and their some chemical and serological properties].

One M perchloric acid-soluble fraction separated from cyst fluid of a patient (blood group AB) with ovarian clear cell carcinoma in malignant was subjected to Sephacryl S-200 gel filtration and Fraction 1 which was eluted at void volume, reacted with both of the lectins of Vicia unijuga and Arachis hypogaea. This fraction was then separated into 6 fractions (DEAE-Frs. 1-6) in a DEAE-Sephacel column chromatography. DEAE-Frs. 3-6 were sugar-rich glycoprotein fractions which contained galactose and N-acetylglucosamine in remarkably high percentages, respectively. Reactivities against various hemagglutinins of these four fractions suggest that DEAE-Fr. 3 is a Thomsen-Friedenreich (T) glycoprotein fraction with AB activity and weak N antigen precursor activity and DEAE-Fr. 4 is an N antigen precursor glycoprotein fraction with AB activity and weak T activity.

Adenocarcinoma↗
PubMed1990

Accumulation of oleate-rich cholesteryl esters by acetyl-LDL in macrophages in the presence of an acyl-CoA: cholesterol acyltransferase inhibitor (Sandoz 58-035).

The mechanism through which cholesteryl esters rich in oleic acid accumulate in the cytoplasm was studied. The fatty acid composition of the cholesteryl esters in acetyl-LDL was high in linoleic acid, while that of cholesteryl ester inclusion bodies accumulated in the cytoplasm was high in oleic acid. This compositional change of fatty acids in cholesteryl esters occurred even in the presence of an acyl-CoA: cholesterol acyltransferase (ACAT) inhibitor, Sandoz 58-035. These results suggest that oleate-rich cholesteryl esters accumulated in the cytoplasm, even though the reesterification in microsome was inhibited by an ACAT inhibitor.

Amides↗
PubMed1989

[Some chemical and serological properties of non-dialysable fractions of human seminal plasmas].

Some chemical and serological properties of water-soluble and undialysable fraction (WSF) and water-insoluble and undialysable fraction (WISF) of human seminal plasmas were studied. Both of the fractions contained proteins as the main components and also carbohydrates as minor components, and each fraction gave 9 bands which were stained with the Periodate-Schiff and/or Coomassie brilliant blue reagents on sodium dodecyl sulfate-polyacrylamide slub gel electrophoresis. WSF reacted with 17 of 19 hemagglutinins, whereas WISF reacted with 12 of them. Although WSF and WISF did not react with anti-M and -N sera respectively, both of the fractions reacted with the anti-N lectins of Vicia graminea and V. unijuga and also with Arachis hypogaea anti-T (Thomsen-Friedenreich) lectin. Perchloric acid-soluble fractions separated from a large number of human intact organ tissues and serum did not react with the above-mentioned 5 hemagglutinins. In double immuno-diffusion, both of the fractions interacted with rabbit anti-WSF serum to form 4 precipitation lines.

Antigen-Antibody Reactions↗
PubMed1989

Monoclonal antibody EMR1a/212D recognizing site of deposition of extracellular lipid in atherosclerosis: purification and characterization of the antigen.

The monoclonal antibody EMR1a/212D, which recognizes the extracellular matrix in which lipids are deposited in atherosclerotic lesions, was developed previously. The macromolecule containing the epitope recognized by this antibody was purified from serum of WHHL rabbits, antigenic material similar to that found in serum and atherosclerotic plaques. The antigenic material was not associated with lipoproteins in serum. The antigenic material was purified in a single band by SDS-PAGE followed by DEAE-Sepharose CL-6B column chromatography (Pharmacia, Uppsala, Sweden), EMR1a/212D coupled immunoaffinity column chromatography, and HPLC equipped with a TSK gel G3000SWXL (Toso, Japan) column. The purified antigenic material was a glycoprotein of molecular weight 66 kd. It was remarkably high in glutamic acid and aspartic acid but low in arginine and lysine. It had an isoelectric point of pH from 5.4 to 5.9. It contained 22.2 mg of sugar per 100 mg protein, and sialic acid at least expressed the activity of the epitope because the antigenic activity was decreased by neuraminidase treatment.

Amino Acids↗
PubMed1989

Quantifying manganese in lymphocytes to assess manganese nutritional status.

To clarify whether manganese nutritional status is better reflected by the manganese concentration in lymphocytes or in whole blood, we injected manganese solutions intravenously into manganese-deficient rats and determined manganese concentrations in lymphocytes, whole blood, and various tissues. The manganese concentrations in lymphocytes and tissues, but not in whole blood, were significantly less in manganese-deficient rats than in normal rats. These low values could be prevented by intravenous injection of manganese in a dose-dependent manner. These results suggest that, for assessment of manganese nutritional status, measurement of manganese in lymphocytes is better than that in whole blood.

Animals↗
PubMed1988

Monoclonal DLR1a/104G antibody recognizing peroxidized lipoproteins in atherosclerotic lesions.

Monoclonal DLR1a/104G antibody which recognizes peroxidized lipoproteins was raised. Mice were immunized with the float-up fraction of the atherosclerotic arterial homogenate from WHHL rabbits. Sensitized spleen cells were fused with myeloma cells (P3/U1). Hybridoma clones were selected using peroxidized LDL prepared by CuSO4-catalyzed peroxidation and native LDL as positive and negative standards, respectively. The monoclonal DLR1a/104G antibody was highly reactive with peroxidized LDL, slightly with LDL modified with malondialdehyde, but not significantly with acetyl- or native LDL. The antigenicity in the case of peroxidized LDL did not decrease on extraction with hexane/isopropanol (3:2). The antigenicity coincided with the fluorescence (E350, F430) of the protein fraction of LDL peroxidized with CuSO4. These results suggest that an antigenic determinant exists in atherosclerotic lesions which is the same as that for lipoproteins peroxidized with CuSO4.

Animals↗
PubMed1988

Characteristics of taurine transport system and its developmental pattern in mouse cerebral cortical neurons in primary culture.

Developmental patterns and pharmacological and biochemical properties of taurine transport system were investigated using developing primary cultured neurons prepared from mouse cerebral cortex by trypsin treatment. [3H]Taurine was incorporated into neurons via a high-affinity transport system of which the Km value as well as the Vmax value increased during neuronal development in vitro. This transport system was also inhibited by sodium withdrawal from incubation medium and exposures for 15 h to several metabolic inhibitors such as 2,4-dinitrophenol and monoiodoacetate. In addition, [3H]taurine uptake in both neurons cultured for 3 and 14 days was competitively inhibited by beta-alanine, guanidinoethanesulfonate and hypotaurine. Cysteic acid and cysteine sulfinic acid, metabolic intermediates produced in the process of taurine biosynthesis in the brain from cysteine, induced significant reductions in [3H]taurine uptake in both types of cultured neurons, while cysteine, isethionic acid, cysteamine and cystamine exhibited no alterations in [3H]taurine transport. Moreover, non-competitive inhibition of [3H]taurine uptake by cysteic acid was observed in both neurons. These results clearly indicate that taurine uptake was mediated by the sodium- and energy-dependent transport system with high affinity in 14-day-old neurons as well as neurons cultured for 3 days and that both the Km and Vmax values of this transport system increase during neuronal development in vitro. The results described above suggest that the decrease in taurine content observed in developing brain is unlikely to be due to alteration in the capacity of the taurine transport system during neuronal development.

Amino Acids↗
PubMed1988

Binding of lectins to "young" and "old" human erythrocytes.

"Old" human erythrocytes showed a 21.2% decrease in cell surface area and a 2% decrease in the number of WGA receptor sites, but a 27% increase in the distribution density of the WGA (lectin) receptor site, when compared with "young" human erythrocytes. For a list of lectin abbreviations, see Materials and methods). Both "young" and "old" erythrocytes exhibited very weak binding activity for 125I-labeled PNA, but there was no difference in binding activity for PNA between "young" erythrocytes and "old" ones. Compared with "young" erythrocytes, decreases in the number and distribution density of receptor sites for five lectins including LPA, Con A, RCA-II, SBA and BPA on the cell surface were observed in aged erythrocytes. "Old" erythrocytes also showed a decrease in the number of PHA-E receptor sites, while the distribution density of the same receptor site remained unchanged. In view of these and other observations, it is thought that human erythrocyte aging is accompanied by elimination of some glycoconjugates which have affinity for six lectins, LPA, Con A, RCA-II, PHA-E, SBA and BPA, whereas no WGA receptor-containing glycoconjugates are released from erythrocyte membranes. Elimination of the glycoconjugates results in shrinkage of erythrocytes to reduce their cell surface areas.

Arachis↗
PubMed1988

Number and distribution density of ABH and MN antigen sites on young and old human erythrocyte surfaces.

There were no differences in the number of A and M antigen sites between young and old human erythrocyte surfaces. No essential differences in the number of A1, N and Vicia graminea N antigen sites could be observed between young and old erythrocytes. The number of B and H antigen sites on cell surface was significantly higher in young erythrocytes than in old ones. The distribution density of A and M antigen sites on young erythrocyte was remarkably higher than that on old ones. Compared with young erythrocytes, significant increases in the distribution density of A1, B, H, N and Vicia graminea N antigen sites were observed in aged erythrocytes. It is suggested from these and other observations that human erythrocyte aging is accompanied by elimination of a small amount of B and H antigens from cell membranes, while A, A1, M, N and Vicia graminea N antigens are not released from cell membranes during in vivo aging.

ABO Blood-Group System↗
PubMed1988

Comparative study on the main membrane-surface sialoglycopeptides released from young and old human erythrocytes with trypsin.

1. The amount of sialoglycopeptide (SGP) mixture released from young (Y) erythrocytes by trypsin treatment was significantly larger than that from old (O) ones. 2. The two main membrane-surface sialoglycopeptides (Y-SGP and O-SGP) were isolated in yields of about 45% and 42% from the mixtures by a combination of Sephadex G-50 superfine gel filtration with DEAE-cellulose chromatography, respectively. Molecular weights of 12,000 and 12,100, respectively, were found for the Y-SGP and the O-SGP. 3. The Y-SGP showed a greater proportion of sialic acid than the O-SGP. The contents of galactose, N-acetylglucosamine and N-acetylgalactosamine of the Y-SGP were significantly lower than those of the O-SGP. 4. Both the SGPs exhibited the same reactivities against the MN reagents, but the reactivities against the lectins of Limulus polyphemus and Phaseolus vulgaris (E) were stronger in the Y-SGP than in the O-SGP. Neither the Y-SGP nor the O-SGP showed the reactivity to Arachis hypogaea (anti-T) lectin.

Amino Acids↗
PubMed1988

Intracellular transport of cholesteryl esters from lysosomes to cytoplasm in macrophages.

The mechanism through which nonmembranous lipid inclusion bodies consisting of cholesteryl esters accumulate in the cytoplasm was studied. Most lipid inclusion bodies in macrophages after 24 h incubation with anisotropic cholesteryl oleate liquid crystals were surrounded by a limiting membrane. The limiting membrane, however, could not be observed after further incubation for 48 h in the presence of esterastin, which is known to be an inhibitor of lipase and esterase. Under these conditions, the levels of hydrolysis and re-esterification of cholesteryl esters were less than 15% and 5% of the control ones, respectively. These results suggest that the inclusion bodies were transferred from lysosomes to the cytoplasm, with partial hydrolysis of cholesteryl esters, in addition to through the pathway via microsomes.

Animals↗
PubMed1988

Anti-cancer therapy with valine-depleted amino acid imbalance solution.

For the purpose of developing amino acid imbalance solution applicable to cancer treatment, we prepared seven kinds of amino acid imbalance solutions based on a 10% balanced amino acid solution and investigated the anti-tumor effects of each solution. The administration of valine-depleted amino acid solution for 8 days at a daily dose of 53 ml/rat (79.5 kcal/rat) resulted in the most significant inhibitory effects on the growth of hepatoma (AH109A) and mammary tumors (MRMT-1), the rate being 82.8% and 90.8%, respectively. Side effects observed were inhibition of increases in host body weight, weight loss of the spleen and thymus, loss of hair, and a decrease in the amounts of total plasma protein and albumin. When the daily dosage of valine-depleted amino acid solution was reduced to 40 ml/rat (58.3 kcal/rat), anti-tumor effects were still noticed, while side effects were abated. These findings indicate that side effects accompanying the use of this solution can be alleviated by controlling the ingredients of the solution as well as the amount administered. It is thus suggested that valine-depleted amino acid imbalance solution is a valuable tool in the treatment of cancer.

Amino Acids↗
PubMed1987

Effect of PGI2 on transcellular transport of fluorescein dextran through an arterial endothelial monolayer.

The effects of prostacyclin (PGI2) and stable derivatives of PGI2, such as isocarbacyclin (PGI2 deriv. (A] and isocarbacyclin methyl ester (PGI2 deriv. (B)), on junctional transport of fluorescein dextran (FD) through cultured porcine arterial endothelial cells were investigated. These PGI2S inhibited the transcellular transport dose-dependently. After the elimination of PGI2, its inhibitory effect persisted for at least 1 hr. A good correlation was found between increase of cAMP and the potency of inhibition. Increase of cAMP after PGI2 treatment seemed to be involved in the inhibition of FD transport.

1-Methyl-3-isobutylxanthine↗