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Biomedical subjects

Y C Kim

Publications and source records attributed to Y C Kim.

At least 217 records · Page 12Linked to original sources
PubMed1997

Potentiation of acetaminophen hepatotoxicity by acute physical exercise in rats.

Effects of acute physical exercise on the acetaminophen-induced hepatotoxicity were examined in adult female rats. Rats were forced to move at a speed of 10 m/min for 2 hr in a rotating cage. Immediately following the exercise bout rats were treated with acetaminophen (APAP; 700 mg/kg, i.p.). The physical exercise enhanced the hepatotoxicity of APAP as shown by increases in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities measured 24 hr following the treatment. A significant decrease in hepatic glutathione (GSH) was observed in the rats forced to exercise suggesting that the enhancement of APAP hepatotoxicity was associated with the depression of this endogenous tripeptide. The role of adrenergic stimulation in the exercise-induced hepatic GSH depression was examined by pretreating the animals with a receptor specific adrenergic antagonist, such as prazosin HCl (15 mg/kg, i.p.), propranolol HCl (15 mg/kg, i.p.), and yohimbine HCl (15 mg/kg, i.p.) 15 min prior to the exercise bout, but neither of the antagonists prevented the GSH depression. Administration of alpha-tocopherol acetate (450 mg/kg/day for 3 days and 150 mg/kg on day 4, i.p.) did not affect the exercise-induced GSH depression or lipid peroxidation in liver homogenates as determined by increases in malondialdehyde formation. These results suggest that neither adrenergic stimulation nor oxidative stress plays a significant role in the enhancement of APAP hepatotoxicity and hepatic GSH depression induced by acute physical exercise.

Acetaminophen↗
PubMed1997

Sex-dependent differences in the disposition of 2,4-dichlorophenoxyacetic acid in Sprague-Dawley rats, B6C3F1 mice, and Syrian hamsters.

2,4-Dichlorophenoxyacetic acid (2,4-D), a widely used broadleaf herbicide, is under investigation in a study of peroxisome proliferators. To supplement that study, male and female rats, mice, and hamsters were dosed with 14C-2,4-D orally at 5 and 200 mg/kg and tissue distributions were determined. Blood, liver, kidney, muscle, skin, fat, brain, testes, and ovaries were examined. At early time points tissues from female rats consistently contained higher amounts of radioactivity than did corresponding tissues from males (up to 9 times). By 72 hr, tissue levels were equivalent and males and females had excreted equal amounts of radioactivity. This sex difference was absent in mice. In hamsters, males had higher tissue levels than females. Taurine, glycine, and glucuronide conjugates of 2,4-D were excreted along with parent. Metabolite profiles differed between species qualitatively and quantitatively; however, differences between sexes were minimal. Plasma elimination curves were generated in male and female rats after iv and oral administration. Kinetic analysis revealed significant differences in elimination and exposure parameters consistent with a greater ability to clear 2,4-D by male rats relative to females. This suggests that at equivalent doses, female rats are exposed to higher concentrations of 2,4-D for a longer time than males and may be more susceptible to 2,4-D-induced toxicity. These sex-dependent variations in the clearance of 2,4-D in rats and hamsters may indicate a need for sex-specific models to accurately assess human health risks.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1997

Zeaxanthin dipalmitate from Lycium chinense has hepatoprotective activity.

We previously reported the isolation of zeaxanthin and zeaxanthin dipalmitate using bioactivity-guided fractionation to discover hepatoprotective components of Lycium chinense against carbon tetrachloride induced hepatotoxicity. The present study was designed to uncover the effects of zeaxanthin dipalmitate on hepatic parenchymal and nonparenchymal cells in vitro. Uptake of [3H]thymidine by cultured rat Ito cells in response to zeaxanthin dipalmitate was measured. Collagen synthesis was assessed by the collagenase digestion method. The effects of zeaxanthin dipalmitate on the formation of nitric oxide (NO) and the release of tumor necrosis factor-alpha (TNF-alpha) from Kupffer cells and peritoneal macrophages were also assayed. Zeaxanthin dipalmitate showed a significant hepatoprotective activity against carbon tetrachloride toxicity. Cellular malondialdehyde (MDA) levels declined significantly with the treatment of the compound in a concentration dependent manner. Zeaxanthin dipalmitate significantly inhibited the uptake of [3H]thymidine by Ito cells. Zeaxanthin dipalmitate also reduced collagen synthesis in Ito cells by 65.1% (p < 0.05) as compared to untreated controls. The formation of NO in either Kupffer cells or in peritoneal macrophages was significantly decreased by zeaxanthin dipalmitate in a concentration dependent manner. The release of TNF-alpha was somewhat less affected by the compound. From these results, we conclude that zeaxanthin dipalmitate exerts a potent hepatoprotective activity by inhibiting Ito cell proliferation, collagen synthesis and by inhibiting certain biochemical functions of Kupffer cells.

Animals↗
PubMed1996

Derivatives of the triazoloquinazoline adenosine antagonist (CGS15943) are selective for the human A3 receptor subtype.

The adenosine antagonist 9-chloro-2-(2-furanyl)[1,2,4]triazolo[1,5-c]quinazolin-5-amine (CGS15943) binds to human A3 receptors with high affinity (Ki = 14 nM), while it lacks affinity at rat A3 receptors. Acylated derivatives of the 5-amino group and other modifications were prepared in an effort to provide A3 subtype selectivity. Affinity was determined in radioligand binding assays at rat brain A1 and A2A receptors using [3H]-(R)-PIA ([3H]-(R)-N6-(phenylisopropyl)-adenosine) and [3H]CGS 21680 ([3H]-2-[[4-(2-carboxy ethyl)phenyl]ethylaminol]-5'-(N- ethyl- carbamoyl)adenosine), respectively. Affinity was determined at cloned human A3 receptors using [125I]AB-MECA (N6-(4-amino-3-iodobenzyl)-5'-(N-methylcarbamoyl)adenosine). A series of straight chain alkyl amides demonstrated that the optimal chain length occurs with the 5-N-propionyl derivative, 3, which had a Ki value of 7.7 nM at human A3 receptors, and was 40- and 14-fold selective vs rat A1 and A2A receptors, respectively. The 5-N-benzoyl derivative, 10, displayed Ki values of 680 and 273 nM at rat A1 and A2A receptors, respectively, and 3.0 nM at human A3 receptors. A 5-N-phenylacetyl derivative, 12, was 470-fold selective for human A3 vs rat A1 receptors with a Ki value of 0.65 nM. A conjugate of Boc-gamma-aminobutyric acid was also prepared but was nonselective. Conversion of the 5-amino group of CGS15943 to an oxo function resulted in lower affinity but 15-fold selectivity for human A3 receptors.

Adenosine↗
PubMed1996

Structure of catechol 2,3-dioxygenase gene encoded in chromosomal DNA of Pseudomonas putida KF715.

A catechol 2,3-dioxygenase gene in chromosomal DNA of P. putida KF715 was cloned and its nucleotide sequence analyzed. The enzyme gene was composed of 924 base pairs with ATG initiation codon and TGA termination codon, which can encode a polypeptide of molecular weight 35 kDa containing 307 amino acids. A promoter-like sequence and a ribosome-binding sequence were identified upstream the enzyme gene. A deduced amino acid sequence of the catechol 2,3-dioxygenase exhibited 94% identity with that of corresponding enzyme in TOL plasmid and 25% identity with that of 2,3-dihydroxybiphenyl 1,2-dioxygenase from the same strain. Furthermore, sequence comparison of the catechol 2,3-dioxygenase with other extradiol-type dioxygenases has led to identify evolutionally conserved amino acid residues whose possible catalytic roles are proposed.

Amino Acid Sequence↗
PubMed1996

cDNA cloning, expression, and chromosomal localization of Caenorhabditis elegans DNA topoisomerase I.

By screening Caenorhabditis elegans cDNA libraries, overlapping cDNA clones encoding DNA topoisomerase I were obtained. An open reading frame of 751 amino acids was found in 3.2-kb cDNA sequence. The open reading frame has 54% and 50% identities to the amino acid sequences of human and Drosophila melanogaster DNA topoisomerases I, respectively. Northern blot analysis showed the presence of an mRNA of 3.4 kb which suggests that the cDNA sequences is close to full length. The 72-kDa C-terminal polypeptide expressed in Escherichia coli cells showed catalytic DNA topoisomerase I activity. The DNA topoisomerase I gene was mapped to position 18 of chromosome I by screening polytene YAC plasmid DNAs.

Amino Acid Sequence↗
PubMed1996

Bioactive steroidal alkaloids from Solanum umbelliferum.

Bioassay-directed fractionation of the MeOH extract of Solanum umbelliferum afforded solasodine (1), O-acetylsolasodine (2), and solasodine 3-O-beta-D- glucopyranoside (3). Alkaloids 1 and 2 exhibited significant activity toward DNA repair-deficient yeast mutants, whereas 3 and the synthetic analogues N-acetylsolasodine (4) and N,O-diacetylsolasodine (5) were found to be inactive. Compounds 2 and 3 are new natural products.

Antineoplastic Agents, Phytogenic↗
PubMed1996

New bioactive cerebrosides from Arisaema amurense.

From Arisaema amurense, four new cerebrosides were isolated along with a known cerebroside. The new cerebrosides were characterized as 1-O-beta-D-glucopyranosyl- (2S,3R,4E,8Z)-2-[(2(R)- hydroxyicosanoyl)amido]-4,8-octadecadiene-1,3-diol (1), 1-O-beta-D- glucopyranosyl-(2S,3R,4E,8Z)- 2-[(2-hydroxyoctadecanoyl)amido]-4,8-octadecadiene-1,3-diol (2), 1-O-beta-D- glucopyranosyl- (2S,3R,4E,8E)-2-[(2-hydroxyicosanoyl)amido]-4,8-oct adecadiene-1,3-diol (4), and 1-O-beta-D- glucopyranosyl-(2S,3R,4E,8E)-2-[(2-hydroxyoctadecanoyl )amido]-4,8- octadecadiene-1,3-diol (5), respectively. These cerebrosides displayed significant antihepatotoxic activity.

Animals↗
PubMed1996

Statistical analysis of amputations and trends in Korea.

Epidemiological research on amputees is being continued extensively world wide, but there are different epidemiologic reports from country to country. This study undertakes an epidemiologic report of the medical records of amputees in Korea which has developed very rapidly, when compared with other countries. This study included 4258 amputees who either had an amputation and/or received prosthetic training at Yonsei University College of Medicine, Severance Hospital from January 1970 to June 1994. The most common cause of amputation was trauma (66.7%), and the second most common cause was peripheral vascular disease. While amputations due to infection or trauma were the most common in the 1950's, amputations due to peripheral vascular disease have gradually increased until they now make up 23.5% of all amputations in the 1990's. Lower limb amputation, more common than upper limb amputation, accounted for 68.7% of all amputation. Multiple amputation accounted for 9.3% of all amputations, and the occurrence rate of multiple amputation was relatively higher in cases of burn injuries, train accidents, frostbite, and Buerger's disease than in cases brought about by other causes. The various amputation causes change according to the circumstances of the times, as can be seen in this study.

Adolescent↗
PubMed1996

Efficacy of hydrocolloid occlusive dressing technique in decubitus ulcer treatment: a comparative study.

The efficacy of hydrocolloid occlusive dressing technique was compared with that of the conventional wet-to-dry gauze dressing technique in decubitus ulcer of stage I and II. Forty-four patients were randomly divided into two treatment groups and each received treatment according to the two different protocols. As a result, 80.8% of the hydrocolloid occlusive dressing group (group 1) and 77.8% of the conventional wet-to-dry gauze dressing group (group 2) healed completely with no statistically significant difference between the two groups. However, the time required for complete healing was shorter in group 1 with 18.9 days compared to 24.3 days in group 2. Ulcer healing speed was also slightly faster in group 1 with 9.1 mm2/day compared to 7.9 mm2/day for group 2. Average treatment time spent by a medical staff member was significantly shorter in group 1 with 20.4 minutes/day compared to 2017 minutes/day in group 2. The hospital cost of the ulcer treatment was higher in group 2 compared to group 1 even without taking into consideration the medical personnel's labor cost. These results indicate that the hydrocolloid occlusive dressing technique offers less time consuming and less expensive method of treatment compared to the conventional technique in stage I and II decubitus ulcers.

Adult↗
PubMed1996

Intraoperative monitoring of microvascular decompression in hemifacial spasm.

The significance of intraoperative electrophysiologic monitoring during microvascular decompression was evaluated prospectively in 261 patients with the hemifacial spasm from 1985 to 1995. The patients were divided into a monitored group and a non-monitored group. Identification of the offending vessels was facilitated by the monitoring during the surgical procedure and the complication rate of the monitored group was significantly lower than that of the non-monitored group (p < 0.05). In addition, the abnormal muscle response continued to improve during the follow-up period, thus the electrophysiological status of the hemifacial spasm after the microvascular decompression improved significantly with time (p < 0.05). In conclusion, intraoperative monitoring is useful for identifying the exact offender among multiple vessels, and lowering the complication rate of the microvascular decompression for the hemifacial spasm.

Adult↗
PubMed1996

A comparison of serum CYFRA 21-1 and SCC Ag in the diagnosis of squamous cell lung carcinoma.

To evaluate the usefulness of CYFRA 21-1 and SCC Ag in the diagnosis of squamous cell carcinoma (SQC) of the lung, we tested sera from 124 patients with lung cancers (squamous cell ca 72, adenoca 22, large cell ca 4, small cell ca 18 and undetermined 8) and 78 patients with inflammatory lung diseases (bronchitis 24, bronchiectasis 29, tuberculosis 19 and others 6) using immunoradiometric assay kit for cytokeratin fragment 19 (CYFRA 21-1) and radioimmunoassay kit for SCC Ag. The serum CYFRA 21-1 and SCC Ag were significantly higher in lung cancer patients compared with control subjects. However, the significant difference was restricted only to SQC. In patients with SQC, CYFRA 21-1 and SCC Ag showed significantly higher levels according to the advanced anatomic stages (stage I-IIIa vs. stage IIIb, IV, p < 0.05). There was a good correlation between CYFRA 21-1 and SCC Ag (r = 0.41, p < 0.001). Receiver operating characteristic (ROC) curves were generated from results of both tumor markers and areas under the curves (AUC) were calculated. AUC of CYFRA 21-1 (0.93) were significantly larger than that of SCC Ag (0.77) for the diagnosis of SQC (p < 0.05). Therefore, we conclude that CYFRA 21-1 is superior to SCC Ag in the diagnosis of squamous cell carcinoma of the lung.

Aged↗
PubMed1996

Acute lung injury after phosgene inhalation.

Phosgene (COCl2) is a colorless oxidant gas which is heavier than air and the lethal exposure dose (LC50) in humans is 500 ppm/min. This gas was originally manufactured as an agent for chemical warfare during World War I and there had been a great deal of studies on phosgene poisoning during the early years of industrial use. It is still widely used in the synthesis of chemicals and plastics. In the modern era, however, phosgene poisoning is relatively uncommon except in accidental exposures. In Korea, there has been no report about lung injury from phosgene inhalation. We present a clinical experience with six patients accidentally exposed to phosgene.

Accidents, Occupational↗
PubMed1996

DNA ploidy and proliferative activity in bcl-2 expressed non-small cell lung cancer.

OBJECTIVES: The expressions of bcl-2 have been reported recently in non-small cell lung carcinoma (NSCLC*). As oncogensis is believed to involve a number of genetic alterations, there can be differences in DNA ploidy or proliferative activity even in bcl-2 positive cases according to the superimposed genetic events. SUBJECTS AND METHODS: On the assumption that we might further discern the biologic behavior of bcl-2 positive NSCLC according to the status of DNA ploidy and proliferative activity, we conducted a study for bcl-2 expression with immunohistochemical staining and DNA analysis on 52 surgical specimens of NSCLC. RESULTS: The bcl-2 was positive in 52% (27/52) of specimens, According to the status of bcl-2 expression, there were no significant differences in tumor stages, performance status score and survival time. Among bcl-2 positive NSCLC, aneuploidy and high proliferative activity were noted in 40% and 44%, respectively. In cases with squamous cell carcinoma (SQC**), the proportion of aneuploidy was significantly higher in bcl-2 positive group compared to bcl-2 negative group (p < 0.01), which could not be explained with the sole effect of bcl-2. In bcl-2 positive NSCLC, there was no significant survival difference by the status of DNA analysis results. With a Coxproportional hazard model, only T stage was an independent prognostic factor. CONCLUSION: In bcl-2 expressed NSCLC, proliferative activity and DNA ploidy were not homogeneous, suggesting other genetic alterations. This may explain our results which showed no differences in survival according to the status of the bcl-2 expression.

Adult↗
PubMed1995

Insulin stimulation of intracellular free Ca2+ recovery and Ca(2+)-ATPase gene expression in cultured vascular smooth-muscle cells: role of glucose 6-phosphate.

Wa have previously reported that insulin accelerates recovery of intracellular Ca2+ concentrations ([Ca2+]i) from pressor agonist-induced Ca2+ loads and stimulates both plasmalemmal and sarcoplasmic-reticulum Ca(2+)-ATPase gene expression in cultured and freshly isolated vascular smooth-muscle cells (VSMCs), suggesting that insulin attenuation of vascular tone may result from modulation of [Ca2+]i. Accordingly, we have now evaluated the linkage between this insulin-regulation of VSMC[Ca2+]i and classical actions of insulin (i.e. glucose transport and metabolism). Cultured VSMCs were incubated in the presence or absence of insulin in a medium containing either pyruvate, glucose, 3-O-methylglucose or 2-deoxyglycose. Insulin caused an 87% increase in [Ca2+]i recovery rate after stimulation with arginine-vasopressin (P < 0.01) and caused a marked increase in Ca(2+)-ATPase mRNA and protein levels in the presence of glucose. Comparable increases in both [Ca2+]i recovery and Ca2(+)-ATPase expression were found when glucose was replaced by 2-deoxyglucose. In contrast, no stimulation was found in either the glucose-free or 3-O-methylglucose-containing medium. As both glucose analogues are transported, but only 2-deoxyglucose is phosphorylated, this indicates that glucose transport and metabolism to glucose 6-phosphate is essential for insulin regulation of VSMC [Ca2+]i, possibly via a glucose-6-phosphate-dependent carbohydrate-response element in the Ca2(+)-ATPase gene.

Animals↗
PubMed1995

Papillary serous carcinoma of the peritoneum in women. A clinicopathologic and immunohistochemical study.

BACKGROUND: Papillary serous carcinoma of the peritoneum (PSCP) is a primary peritoneal tumor in women that histologically resembles papillary serous carcinoma of the ovary (PSCO). Recognition of PSCP as an entity is controversial, as is the histogenesis, histopathologic differential diagnosis, and treatment. METHODS: Ten cases of PSCP retrieved from the pathology files of 4 hospitals in Kyoto and Nara, Japan, were studied clinicopathologically and immunohistochemically. RESULTS: Patient ages at presentation ranged from 40 to 74 years (median, 56 years). All patients were Asian (Japanese). None of the patients had a history of asbestos exposure. Most of the patients had abdominal swelling, ascites with positive cytology, and elevated serum CA125. At surgery, omental tumors with dissemination to the abdominal and pelvic peritoneum were found in all patients. The histology was similar to that of Grade 2 to 3 PSCO. Immunohistochemical studies using a panel of monoclonal antibodies against carbohydrates showed that Lewis Y is a good marker, in addition to S-100, placental alkaline phosphatase, CA125, and CD15 for separating PSCP from malignant mesothelioma (MM). With cytoreductive surgery and cisplatin-based combination chemotherapy and in some cases adoptive immunotherapy and radiation, a median survival of 27 months and a 5-year survival rate of 27% were attained. One patient with Grade 3 tumor has survived for more than 6 years after surgery. CONCLUSIONS: (1) Papillary serous carcinoma of the peritoneum is a definite clinicopathologic entity; (2) immunohistochemistry is a useful tool for distinguishing PSCP from MM; (3) cytoreductive surgery and cisplatin-based combination chemotherapy with other adjunct therapies such as immunotherapy and radiation may improve patient survival in PSCP.

Adult↗
PubMed1995

Cloning of salicylate hydroxylase gene and catechol 2,3-dioxygenase gene and sequencing of an intergenic sequence between the two genes of Pseudomonas putida KF715.

The salicylate hydroxylase can convert the salicylate to catechol, and catechol 2,3-dioxygenase catalizes the conversion of catechol to 2-hydroxymuconic semialdehyde. A salicylate hydroxylase gene and a catechol 2,3-dioxygenase have been cloned from chromosomal DNA of P. putida KF715. The two genes have different promoters. An open reading frame with 339 nucleotides preceded by a putative ribosome-binding sequence (GGAGG) was identified in the intergenic sequence between salicylate hydroxylase gene and catechol 2,3-dioxygenase gene of P. putida KF715 and its sequence analyzed. This open reading frame can encode a polypeptide of molecular weight 13 kDa containing 112 amino acids, whose sequence exhibited 87% homology with that of ferredoxin encoded in NAH7 of P. putida PpG7 and significant homology with those of redox components in phenol hydroxylase, benzoate 1,2-dioxygenase, toluate 1,2-dioxygenase, xylene monooxygenase, and toluene 4-monooxygenase.

Amino Acid Sequence↗