Search PubMed⌕ Search

Biomedical subjects

J C Cyong

Publications and source records attributed to J C Cyong.

At least 55 records · Page 3Linked to original sources
PubMed1986

Purification and characterization of complement activating-acidic polysaccharide from the root of Lithospermum euchromum Royle.

An extraordinary potent anti-complementary substance was isolated from the root of Lithospermum euchromum Royle (Japanese name: Nan-shikon) which activates the complement system in vitro, and the active principle was shown to be acidic polysaccharide (LR-polysaccharide IIa). LR-polysaccharide IIa was purified by chromatographies on DEAE-Sepharose, Sephadex G-100, concanavalin A-Sepharose, Ricinus communis agglutinin conjugated Sepharose, Sepharose CL-6B and Sepharose CL-2B. LR-polysaccharide IIa was found to be composed of rhamnose, fucose, arabinose, xylose, mannose, galactose and glucose in the molar ratios of 2.0:2.5:3.4:2.8:5.6:9.6:14.4. The polysaccharide also contained 15% of galacturonic acid and 3.8% of protein. The methylation analysis of the polysaccharide showed that rhamnose, arabinofuranose, xylose, glucose and galactose are present as a part of the nonreducing terminal residues. The main chain and side chains are composed of ----3Glc1----,----3Gal1----,----6Man1----,----4Gal1, [corrected] and the branching points consist of (formula; see erratum) These results indicated that LR-polysaccharide IIa has a highly complicated structure. A marked consumption of C4 was observed after the incubation of the serum with LR-polysaccharide IIa in the presence of the Ca++ ion. The anti-complementary activity of LR-polysaccharide IIa was reduced partially in the absence of the Ca++ ion. After the incubation of the serum with LR-polysaccharide IIa in the absence of Ca++ ion, a cleavage of C3 in the serum was found to have occurred through immunoelectrophoresis as well as from the consumption of the complement when rabbit erythrocytes were used in the assay system. These results indicate that the mode of complement activation by LR-polysaccharide IIa is via both the alternative and classical pathways. Complement titer also decreased in guinea pigs upon i.p. injection of LR-polysaccharide IIa.

Animals↗
PubMed1986

Studies on polysaccharides from Angelica acutiloba. V. Molecular aggregation and anti-complementary activity of arabinogalactan from Angelica acutiloba.

Anti-complementary active arabinogalactan IIb-1 (AGIIb-1) and inactive arabinogalactan IIb-2 (AGIIb-2) were isolated from an extract of the root of Angelica acutiloba Kitagawa. AGIIb-1 mainly consisted of arabinose, galactose, rhamnose and galacturonic acid in a molar ratio of 2.2:1.0:0.3:0.4, and AGIIb-2 mainly consisted of arabinose, galactose, galacturonic acid, and glucuronic acid in a ratio of 1.0:1.0:0.08:0.1. AGIIb-1 was found to form molecular aggregates as the result of self-aggregation in water. The aggregated form was found in the void volume by gel filtration using Sepharose CL-2B in water. However, AGIIb-2 did not show this behavior. When the AGIIb-1 aggregate was applied to a gel filtration column in 8 M urea or NaCl solution, the position of the peak fraction shifted to a lower molecular weight region, and the molecular weight of AGIIb-1 decreased with the increase of NaCl concentration in the gel filtration. These results suggested that the molecular aggregation of AGIIb-1 was caused by hydrogen bonding and ionic interaction and was Ca2+ ion independent. The anti-complementary activity of AGIIb-1 was seen to be dependent upon the degree of molecular aggregation, and the AGIIb-1 aggregate in water showed the highest activity. The results of methylation analysis indicated that AGIIb-1 contained a large amount of 3,5- or 3,4-di-O-substituted arabinosyl residues whereas AGIIb-2 contained a large amount of 6-O-substituted galactopyranosyl residues.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrates↗
PubMed1985

Studies on polysaccharides from Angelica acutiloba--IV. Characterization of an anti-complementary arabinogalactan from the roots of Angelica acutiloba Kitagawa.

An anti-complementary polysaccharide, AR-arabinogalactan, was isolated from the roots of Angelica acutiloba Kitagawa (Japanese name = Yamato-Tohki), and purified by chromatography on DEAE-Sephadex A-50, Sephadex G-100, Sepharose CL-2B and concanavalin A-Sepharose. AR-arabinogalactan was composed of arabinose and galactose in a molar ratio of 1.2:1.0 and a small amount of galacturonic acid. The results of methylation and exo-alpha-L-arabinofuranosidase treatment showed that the polysaccharide was a branched arabinogalactan containing a backbone involving galactopyranosyl (1----6) linkages. Most of the arabinose was present as an alpha-L-furanosyl residue in the non-reducing terminals and side chains. The (1----3)-linked galactopyranosyl residue might be linked to the arabinosyl side chains. alpha-L-arabinofuranosidase digestion did not destroy the anti-complementary activity of the polysaccharide. After incubation of the serum with AR-arabinogalactan in the absence of Ca2+ ions, a cleavage of C3 in the serum was detected by immunoelectrophoresis as well as from the consumption of complement when rabbit erythrocytes were used in the assay system. A marked consumption of C4 was also observed to have occurred when serum was incubated with AR-arabinogalactan in the presence of Ca2+ ions. Collectively considered these results indicate that the mode of complement activation by AR-arabinogalactan is via both the alternative and the classical pathway.

Arabinose↗
PubMed1985

The development of complement activating ability as an age related factor in murine brains.

We recently reported on the ability of the myelin fraction of the murine brain to activate the complement system through the classical pathway, which might be important in the induction of secondary inflammation in various pathological conditions where brain tissue has been exposed to the complement. The present study was undertaken to investigate the relationship between the appearance of complement activity in the mouse brain and the synthesis of myelin in ICR mice up to ninety days of age. Here, we show that anti-complementary activity in the murine brain is closely related to murine brain weight and that its activity seems to be dependent on the amount of myelin in the murine brain. Myelin was isolated from brains of equal weight taken from both two-day old and ninety-day-old mice, and we found that ninety-day-old myelin consumed a much greater amount of complement (C) than two-day-old myelin. However, for equal concentrations of myelin, almost an equal amount of C was consumed by the myelin of the two-day-old mice and by that of the ninety-day-old mice. It was suggested that the difference of anti-complementary activity was caused by the myelin contents of the murine brains, but the possibility of maturation of myelin was not excluded. The mechanism involved in the anticomplementary activity of the myelin was found to be related to the consumption of complement, mainly via the classical pathway but also less activity via the alternative pathway.

Aging↗
PubMed1982

Antibody-independent complement activation by myelin via the classical complement pathway.

Murine or rabbit whole brain homogenates were shown to activate human complement via the classical pathway by an antibody-independent reaction. This activity required Ca++ ions. Anticomplementary activity in fractionated murine brain was found to reside in the myelin fraction and in purified myelin. It was absent, however, both from highly purified myelin basic protein (MBP) and from the MBP-free residue. Because purified MBP is a monomer and this protein exists in brain tissue largely as a dimer, the ability of the cross-linked form of MBP to activate complement was investigated. MBP, dimerized with difluorodinitrobenzene, was highly anticomplementary. The murine brain, inactive when taken from the newborn mouse, was shown to first acquire the capacity to activate complement at 7 d after birth. This finding is consistent with the report that the synthesis of myelin protein has been shown to be initiated in murine brain 8 d after birth. Complement activation by MBP could play an important role in the pathological changes observed in neurological disorders.

Animals↗
PubMed1982

Comparison of effects of adrenaline, ethylphenylephrine, isoprenaline and terbutaline on the vascular system.

The effects of a single therapeutic dose of sympathomimetics, adrenaline, ethylphenylephrine, isoprenaline and terbutaline on venous return and other peripheral vascular beds were compared in dogs subjected to controlled cardiac output. The intra-aortic administration of adrenaline (1 microgram/kg) produced increases in femoral arterial pressure (FAP), left auricular outflow (LAO) and superior vena-caval flow (S-VCF), while no significant change was observed in inferior vena-caval flow (I-VCF) and femoral venous pressure. Ethylphenylephrine (0.4 mg/kg), a selective alpha-adrenoceptor stimulant, showed almost the same pattern of change but of smaller magnitude as adrenaline, though the duration of the effect was longer. Isoprenaline (1 microgram/kg) showed decreases in FAP and LAO, and marked increases in S-VCF and I-VCF. Terbutaline (20 microgram/kg), a beta2-adrenoceptor stimulant, showed no significant effect on LAO, though other parameters changed with the same pattern produced by isoprenaline.

Animals↗
PubMed1981

Resistance to immune cytolysis induced by 4NQO and MNNG: a possible mechanism involved in chemical carcinogenicity.

L1210 cells were cultured for 20 hr in the presence of 4NQO or MNNG. Both agents rendered L1210 cells resistant to immune cytolysis by rabbit antibody and guinea pig complement. This resistance to immune cytolysis was not due to a loss or a distribution change of antigenic determinants to rabbit antibody, since the treated cells retained the capacity to consume guinea pig C4 in the presence of rabbit antibody to the same extent as untreated L1210 cells. Because acyltransferase activity to incorporate free fatty acids into phospholipids and neutral lipids of L1210 cells increased after the 4NQO and MNNG treatments, it was suggested that there might be a close relationship between the increased resistance of L1210 cells to immune cytolysis and the increase in their acyltransferase activity.

4-Nitroquinoline-1-oxide↗
PubMedDate not supplied

Effects of adrenaline and isoprenaline on hepatic venous haemodynamics and venous return in the dog.

1. The effects of adrenoceptor agonists on venous haemodynamics were examined, utilizing the lower half perfusion method in dogs. 2. Femoral arterial pressure, central venous pressure, thoracic vena caval flow, abdominal vena caval flow, renal venous flow and femoral venous flow were measured simultaneously usning electronic transducers and electromagnetic flow-meters. Hepatic volume change was monitored by the strain-guage arch. 3. Single injections of both adrenaline (1.0 microgram/kg) and isoprenaline (1.0 microgram/kg) intra-aortically produced an increase in venous return, adrenaline transiently and isoprenaline continuously. 4. Epinephrine increased hepatic venous flow, while isoprenaline increased only abdominal vena caval flow. 5. These findings suggest that effects of alpha-adrenoceptors are more pronounced on the hepatic vein, while on other peripheral veins, effects of beta-adrenoceptors are more pronounced.

Animals↗
PubMedDate not supplied

Effects of coffee cherry on the immune system in SHN mice.

Previously, we found that chronic ingestion of the extract of coffee cherry (CC), the residue after the removal of coffee beans, induced a marked suppression of the development and the growth of spontaneous mammary tumours in a high mammary tumour strain of SHN mice. As a possible step to clarify the mechanism of this effect, the immunomodulating role of CC was examined in this study. CC treatment resulted in significant weight gain in the spleen. CC treated experimental mice showed a significant decrease in the proportion of immature (CD4+8+) thymocytes and an increase in the percentages of mature cells expressing helper/inducer (CD4+8-) or cytotoxic/suppressor (CD4-8+) phenotypes. The proportion of T cells expressing CD25, a lymphocyte activation marker, in the spleen and peripheral blood tended to increase in the CC treated group. The natural killer activity of the spleen cells was not affected by CC ingestion. These results have revealed that CC can enhance the differentiation of thymocytes and the activation of peripheral T lymphocytes.

Animals↗