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Biomedical subjects

I M Chang

Publications and source records attributed to I M Chang.

28 records · Page 2Linked to original sources
PubMed1995

Inhibitory effects of Oriental herbal medicines on IL-8 induction in lipopolysaccharide-activated rat macrophages.

Cytokine-induced neutrophil chemoattractant (CINC), a rat interleukin-8 (IL-8), was quantitated by using a sensitive ELISA. The CINC was induced up to 20 ng/ml from basal 1-2 ng/ml in lipopolysaccharide (LPS)-activated peritoneal macrophages. This CINC induction was significantly inhibited by steroidal anti-inflammatory drugs including dexamethasone, but not by non-steroidal drugs including indomethacin at all. Nine out of 59 herbal medicines which are frequently used in Korean traditional prescriptions for inflammatory diseases exhibited more than 50% of inhibition on the CINC induction by their total methanol extracts with 0.1 mg/ml as a final concentration. The active 9 total extracts were prepared from radix of Aralia continentalis, rhizoma of Cnidium officinale, rhizoma of Coptis chinensis, tuber of Fritillaria verticillata, radix of Saussurea lappa, tuber of Sparganium stoloniferum, flower of Syzygium aromaticum, semen of Trichosanthes kirilowii, and herba of Tripterygium regelii. These total extracts were sequentially fractionated with dichloromethane, ethyl acetate, butanol, and water. Among the solvent-fractionated extracts with 0.05 mg/ml as a final concentration, more than 50% of inhibition on the CINC induction was exhibited by the dichloromethane fraction of Aralia continentalis; the water fraction of Fritillaria verticillata; the dichloromethane fraction of Saussurea lappa; the dichloromethane, ethyl acetate, and butanol fractions of Syzygium aromaticum; the dichloromethane, ethyl acetate, and water fractions of Trichosanthes kirilowii; and the dichloromethane and ethyl acetate fractions of Tripterygium regelii.

Animals↗
PubMed1991

Pharmacokinetic study of an iridoid glucoside: aucubin.

Aucubin, a promising hepatoprotecting iridoid glucoside, was given intravenously (iv), orally (po), intraperitoneally (ip), and hepatoportally (pv) to rats. A linear pharmacokinetic behavior was obtained after iv administation of 400-400 mg/kg of aucubin. The half-life of aucubin in the postdistributive phase (t1/2, beta), total-body plasma clearance (CLt), and volume of distribution (Vdss) were 42.5 min, 7.2 ml/min/kg, and 346.9 ml/kg, respectively, for a 40 mg/kg dose. There was no significant difference in the parameters as a reult of increasing dose. The partition coefficients of aucubin between n-octanol and buffers of pH 3.0-10.0 were low, while 18.5 +/- 1.3% of aucubin in whole blood partitioned into the blood cells. Plasma protein binding of aucubin was only 9%. The bioavailabilites of aucubin after administration at a dose of 100 mg/kg through pv, ip, and po routes were 83.5, 76.8, and 19.3%, respectively. The pH-stability profile indicated rapid degradation of aucubin at pH 1.2, 1.6, and 2.0, with degradation half-lives of 5.1, 5.8, and 14.8 hr, respectively, at 37 degrees C. Therefore, the low oral bioavailability of aucubin may be attributed to pH-instability in the gastric fluid, poor GI absorption due to low lipophilicity, and the possible metabolism in the GI mucosa and liver (so called first-pass effect).

Animals↗
PubMed1988

Effect of T-2 toxin on lipid peroxidation in rats: elevation of conjugated diene formation.

A single dose of T-2 toxin (3.6 mg/kg, oral) enhanced conjugated diene formation in rat liver, spleen, kidney, thymus and bone marrow, implying that lipid peroxidation was stimulated. Lipid peroxidation showed apparent specificity in each organ as time elapsed (1-6 h). In liver and kidney maximum stimulation (+74% and +72%, respectively) was noted at 1 h after T-2 treatment. In spleen and thymus, maximum values were observed at 3 h (+95% and +32%, respectively). In bone marrow, a continuous elevation was noted which reached a maximum at 6 h (+112%). Results obtained from serum transaminase assay and histological examination suggested that T-2 toxin exhibited low hepatotoxicity even when the rat received a dose close to the oral LD50.

Animals↗
PubMed1983

Protective effect of Aucuba japonica against carbon tetrachloride-induced liver damage in rats.

Pretreatment of rats with ethanol extract from leaves of Aucuba japonica (600 mg/kg/day, po) for two days protected against CCl4-induced depression in plasma disappearance and biliary excretion of injected sulfobromophthalein (BSP) determined 24 hr after the CCl4 challenge (0.5 ml/kg, ip). Percent recovery of BSP in bile in 60 min for control, CCl4, extract + CCl4 treated rats was 66.8 +/- 1.9, 56.2 +/- 1.4, and 68.9 +/- 2.2, respectively. Pretreatment of the extract also protected CCl4-induced increased serum glutamic-pyruvic transaminase activity and liver necrosis as demonstrated by histological evaluations. However, pretreatment of the extract did not modify the intensity of CCl4-induced lipid peroxidation process or cytochrome P-450 destruction. The results suggest that ethanol extract of Aucuba japonica protects CCl4 hepatotoxicity at a site in the chain events leading to necrosis but not the activation step of CCl4 to X CCl3 and X C1 free radicals.

Animals↗
PubMed1983

Protective activities of aucubin against carbon tetrachloride-induced liver damage in mice.

An iridoid glucoside, aucubin was isolated from Aucuba japonica leaves and its protective activities against CCl4-induced hepatotoxicity were evaluated by measuring the duration of hypnosis induced by hexobarbital after CCl4 challenge (0.2 ml/kg/day, po) and the levels of serum glutamic-oxalacetic (GOT) and serum glutamic-pyruvic transaminase (GPT). The duration of hypnosis for the saline control group, the CCl4 alone treated group and the aucubin plus CCl4 treated group was 24.8 +/- 8.5, 60.5 +/- 9.5 and 28.0 +/- 3.2 min, respectively. Treatment of mice with aucubin also effectively protected against CCl4-induced increased serum GOT and GPT activities. It was found that aucubin inhibited hepatic RNA and protein syntheses in vivo. Such inhibitory effects of aucubin might be responsible for protective activities against CCl4-induced liver damage.

Alanine Transaminase↗
PubMed1982

Corrected group prognostic curves and summary statistics.

A method is presented for correcting distribution function estimators for distortions in the joint distribution of covariates in the subsamples receiving different treatments. This form of standardization is useful for depicting multivariate analyses and predicting population behavior. Furthermore, it also proves useful for comparing two trials which differ in patient mix and for adjusting estimates for know imbalances in patient characteristics. Standardization though important, is not often used in clinical trials because of the complexities introduced by multiple covariates. The proposed method overcomes these difficulties in a wide class of analyses.

Age Factors↗
PubMedDate not supplied

Survey of the presence of the Fusarium mycotoxins nivalenol, deoxynivalenol and T-2 toxin in Korean cereals of the 1989 harvest.

Twenty eight samples of rice, barley, millet, corn and Indian millet harvested in Korea in 1989 were subjected to assay for contamination of nivalenol (NIV), deoxynivalenol (DON) and T-2 toxin by using gas chromatography and gas chromatography-mass spectrometry. Seven samples were found to be positive for NIV and DON in the ranges of 189-624 micrograms/kg and 168-506 micrograms/kg, respectively. Of the contaminated samples, three samples, one barley, one Indian millet and one corn sample were contaminated simultaneously with both NIV and DON. T-2 toxin was not detected in any samples.

Chromatography, Gas↗
PubMedDate not supplied

Interaction of Rhodium(II) carboxylates with molecules of biologic importance.

Rhodium(II) acetate, propionate, and butyrate showed a considerable variation in their antitumor activity against Ehrlich ascites tumor cells in mice, with the butyrate complex being the most active. The three complexes markedly inhibited DNA synthesis of Ehrlich ascites tumor cells in vivo. Rhodium (II) butyrate was the most potent inhibitor followed by the propionate complex. One hour after administration, rhodium(II) propionate and butyrate induce more uridine-5-3H incorporation into RNA than is seen in the controls. Equilibrium dialysis studied showed that rhodium(II) acetate-1-14C binds to single stranded DNA, poly-A, ribonuclease A, and bovine serum albumin but not to highly polymerized native calf thymus DNA, poly-G, or poly-C. In these cases binding occurred at the two axial positions of rhodium(II) acetate to a nitrogen donor in the ligands. The formation constants of the rhodium(II) acetate and propionate complexes with 5'-adenosine monophosphate were determined. The rhodium(II) propionate complex was more stable. Sedimentation and viscosity measurements of poly-A and poly-A/rhodium(II) acetate complexes indicate a high degree of intramolecular crosslinking in the rhodium(II) acetate/poly-A complex. The rhodium(II) carboxylate complexes were also found to be potent inhibitors of purified DNA polymerase I and RNA polymerase from Escherichia coli.

Acetates↗