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Biomedical subjects

D K Kim

Publications and source records attributed to D K Kim.

At least 109 records · Page 6Linked to original sources
PubMed2000

Serotonin transporter gene polymorphism and antidepressant response.

We examined allelic polymorphisms of the serotonin transporter (5-HTT) gene and antidepressant response to 6 weeks' treatment with the selective serotonin reuptake inhibitor (SSRI) drugs fluoxetine or paroxetine. We genotyped 120 patients and 252 normal controls, using polymerase chain reaction of genomic DNA with primers flanking the second intron and promoter regions of the 5-HTT gene. Diagnosis of depression was not associated with 5-HTT polymorphisms. Patients homozygous l/l in intron 2 or homozygous s/s in the promoter region showed better responses than all others (p < 0.0001, p = 0.0074, respectively). Lack of the l/l allele form in intron 2 most powerfully predicted non-response (83.3%). Response to SSRI drugs is related to allelic variation in the 5-HTT gene in depressed Korean patients.

Adult↗
PubMed2000

Benzo[c]phenanthridine alkaloids from Corydalis incisa.

Six benzo[c]phenanthridine alkaloids, corynoline (1), acetylcorynoline (2), corynoloxine (3), luguine (4), 6-oxocorynoline (5), and 12-hydroxycorynoloxine (6) were isolated from the aerial parts of Corydalis incisa, and 6 was isolated for the first time from nature. The structure was elucidated by NMR techniques.

Alkaloids↗
PubMed2000

Activity of crude extract of Rubus crataegifolius roots as a potent apoptosis inducer and DNA topoisomerase I inhibitor.

The effects of methanol extract of Rubus crategifolius roots and its solvent fractions were investigated on the proliferation of MCF-7 human breast carcinoma cells. The methanol extract inhibited the proliferation of MCF-7 cells in a concentration dependent manner. Moreover, their methanol soluble (W-M) fraction had the greatest inhibitory effect on the growth of MCF-7 cells. To evaluate whether the W-M fraction affects on the cell cycle of MCF-7 cells, cells treated with this fraction were analyzed with flow cytometry. The W-M fraction increased G0/G1 phase after 24 h-treatment and induced apoptosis after 48 h-treatment. The hallmark of apoptosis, DNA fragmentation, also appeared by W-M fraction after 48 h-treatment. Furthermore, the methanol extract and its W-M fraction inhibited the activity of the topoisomerase I enzyme in the relaxation assay. From these results, their W-M fraction as well as methanol extract of R. crategifolius roots are necessary for further studies as a potent inhibitor of the growth of cancer cells.

Apoptosis↗
PubMed2000

Inhibitory effect of mast cell-dependent anaphylaxis by Gleditsia sinensis.

We investigated the effect of aqueous extract of Gleditsia sinensis thorns (Leguminosae) (GSAE) on the mast cell-dependent anaphylaxis. GSAE (0.005 to 1 g/kg) dose-dependently inhibited systemic anaphylaxis induced by compound 48/80 in rats. GSAE (0.1 and 1 g/kg) also significantly inhibited local anaphylaxis activated by anti-DNP IgE. When GSAE was pretreated at the same concentrations with systemic anaphylaxis, the plasma histamine levels were reduced in a dose-dependent manner. GSAE (0.001 to 1 mg/ml) dose-dependently inhibited the histamine release from rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. The level of cyclic AMP in RPMC, When CSAE (1 mg/ml) was added, transiently and significantly increased about fourfold compared with that of basal cells. Moreover, GSAE (0.01 and 0.1 mg/ml) had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha production from RPMC. These results suggest a possible use of GSAE in managing mast cell-dependent anaphylaxis.

Anaphylaxis↗
PubMed2000

Spirobenzylisoquinoline alkaloids from Corydalis ochotensis.

Separation of the alkaloids from the aerial parts of Corydalis ochotensis afforded a new spirobenzylisoquinoline alkaloid, 8-O-acetylcorysolidine along with two known spirobenzylisoquinoline alkaloids, isoochotensine and corysolidine.

Alkaloids↗
PubMed2000

Regulation of cytokine production by exogenous nitric oxide in murine splenocyte and peritoneal macrophage.

Nitric oxide (NO), products of activated macrophages, have a great impact on the regulation of cytokine production. The role of NO in non-specific host cells is commonly accepted. On the contrary, its role as an immuno-regulatory molecule is still controversial. In this study, we have investigated the effect of NO on the production of cytokines from murine splenocytes and macrophages. S-nitroso-L-glutathione inhibited the release of both interferone-gamma and interleukin-2 produced by Th1 cells and tumor necrosis factor-alpha and interleukin-1beta produced by macrophages, but did not affect the release of interleukin-4 and interleukin-10 produced by Th2 cells. These results suggest that NO exerts a down-regulatory effect on the secretion of cytokines from Th1 cells and macrophages which are implicated in immune response. Thus, NO may have an important role as an immuno-modulatory as well as effector molecule in the immune system.

Animals↗
PubMed2000

The relationship between the angiographic findings and the clinical features of carotid artery plaque.

The purpose of this study was to investigate the histological characteristics of atheromatous carotid plaque, and to analyze the relationship between the angiographic findings and the clinical features. We retrospectively reviewed 55 cases of carotid endarterectomy for extracranial internal carotid artery stenosis, who were treated at our institute from January 1995 to December 1997. The histological examination included hematoxylin-eosin staining, Masson-trichrome staining, and immunostaining for antismooth muscle antibody and anti-CD68 antibody. The main compositions of the carotid plaque included synthetic type vascular smooth muscle cells and extracellular matrix. The histological findings showed ulceration in 49 (89.1%) cases, calcium deposits in 42 (76.4%) cases, and an inflammatory reaction in 44 (80.0%) cases. Neurological abnormalities were strongly associated with plaque ulceration (P = 0.045) and an inflammatory reaction (P = 0.013), whereas no correlation existed regarding calcium deposits (P = 0.173). The angiographic findings showed ulceration in 46 (83.6%) cases. Plaque ulceration in the angiography findings showed no statistically significant correlation with the histologic findings (P = 0.410) and preoperative neurologic abnormalities (P = 0.059). All of the atherosclerotic risk factors such as hypertension, smoking, diabetes mellitus, hyperlipidemia, and myocardial infarction had no statistically significant correlation with the histological features of the carotid plaque. In conclusion, the main compositions of carotid plaque were synthetic-type vascular smooth muscle cells and extracellular matrix. The histological ulceration and inflammatory reaction of the plaque showed a statistically significant correlation with the preoperative neurologic symptoms, whereas no correlation was seen in the calcium deposits. Angiographic ulceration showed no correlation with the histological findings or preoperative neurologic abnormalities. In addition, the histological findings showed no correlation with the atherosclerotic risk factors.

Aged↗
PubMed2000

Clinical study of SS-cream in patients with lifelong premature ejaculation.

OBJECTIVES: To investigate the clinical efficacy of SS-cream, the topical agent made from the extracts of nine natural products for the treatment of premature ejaculation, we performed a double-blind, randomized, placebo-controlled Phase III clinical study of patients with lifelong premature ejaculation in three medical centers. METHODS: One hundred six patients (mean age 38.7 +/- 0.61 years) completed this study. The ejaculatory latency measured by stopwatch and sexual satisfaction ratio of both partner and patient were investigated twice in the screening period and once after each treatment (1 placebo 0.20 g and 5 SS-cream 0.20 g for a total of six treatments). Patients were instructed to apply the cream on the glans penis 1 hour before sexual intercourse in a double-blind randomized fashion. Clinical efficacy was compared with the prolongation of ejaculatory latency and improvement of the sexual satisfaction ratio before and after each treatment. RESULTS: In the screening period, the mean ejaculatory latency was assessed at 1.37 +/- 0.12 minutes, and neither the patients nor their partners were satisfied with their sexual lives. After treatment, the mean ejaculatory latency was prolonged to 2.45 +/- 0.29 minutes in the placebo group and 10.92 +/- 0.95 minutes in the SS-cream group. The clinical efficacy of placebo and SS-cream as judged by an ejaculatory latency time prolonged more than 2 minutes was 15.09% and 79.81%, respectively. The improvement of sexual satisfaction to a grade higher than effective was 19.81% and 82.19%, respectively, for placebo and SS-cream. Of 530 trials of SS-cream, 98 (18.49%) resulted in a sense of mild local burning and mild pain. No adverse effect on sexual function or partner and no systemic side effects were observed. CONCLUSIONS: According to these results, SS-cream is effective and safe in the treatment of premature ejaculation, with mild local side effects.

Administration, Topical↗
PubMed2000

Nitric oxide-mediated endothelium-dependent relaxation of rat thoracic aorta induced by aqueous extract of red rice fermented with Monascus ruber.

Vasodilatory effects of aqueous extract of red rice fermented with Monascus ruber IFO32318 were examined on the isolated rat aorta. The water phase of fermented rice with Monascus (WP/FRM, 0.1-10 mg/ml) caused a transient relaxation of the endothelium-intact rat aorta precontracted with norepinephrine (NE, 300 nM). The WP/FRM-induced relaxation was abolished by removal of endothelium or in the presence of N(G)-nitro-L-arginine (L-NNA, 10 microM), a nitric oxide (NO) synthase inhibitor. Neither atropine, a muscarinic receptor antagonist (10 microM), nor indomethacin, a cyclooxygenase inhibitor (10 microM), altered the WP/FRM-induced endothelium-dependent relaxation. gamma-Aminobutyric acid (GABA), one of the principle components of the extract, did not affect the muscle tension of the aorta with intact endothelium. In addition, WP/FRM increased the production of NO in primary cultured endothelial cells from human umbilical vein. The enhanced production of NO by WP/FRM was diminished by pretreatment with L-NNA (10 microM). In conclusion, WP/FRM induces relaxation of rat aorta by releasing NO from endothelium. There seem to be some unknown factor(s) other than acetylcholine (Ach) and GABA, in the aqueous extract of red rice, which stimulate vascular endothelial cells to produce and/or release NO leading to endothelium-dependent relaxation by WP/FRM.

Acetylcholine↗
PubMed2000

One-allele system in the Korean for MboI-RFLP in exon 1 of the human tyrosinase (TYR) gene.

Oculocutaneous albinism is an autosomal recessive genetic disorder. Several types of oculocutaneous albinism are caused by mutation in related genes. Oculocutaneous albinism 1 is associated with the tyrosinase gene. The human tyrosinase gene (TYR) encodes tyrosinase, a key enzyme in melanin biosynthesis. As exon 1 of the gene shows an MboI-RFLP within codon 192 in Caucasians, we studied allele frequencies of MboI 192 polymorphism in 200 chromosomes from 100 unrelated normal Korean individuals. As a result, only one allele system, the presence of the MboI 192 site, was detected in the Korean.

Albinism, Oculocutaneous↗
PubMed2000

FACT relieves DSIF/NELF-mediated inhibition of transcriptional elongation and reveals functional differences between P-TEFb and TFIIH.

We report that the chromatin-specific transcription elongation factor FACT functions in conjunction with the RNA polymerase II CTD kinase P-TEFb to alleviate transcription inhibition by DSIF (DRB sensitivity-inducing factor) and NELF (negative elongation factor). We find that the kinase activity of TFIIH is dispensable for this activity, demonstrating that TFIIH-mediated CTD phosphorylation is not involved in the regulation of FACT and DSIF/NELF activities. Thus, we propose a novel transcriptional regulatory network in which DSIF/NELF inhibition of transcription is prevented by P-TEFb in cooperation with FACT. This study uncovers a novel role for FACT in the regulation of transcription on naked DNA that is independent of its activities on chromatin templates. In addition, this study reveals functional differences between P-TEFb and TFIIH in the regulation of transcription.

DNA-Binding Proteins↗
PubMed2000

Identification of multiple forms of membrane-associated neutral sphingomyelinase in bovine brain.

Many different stimuli such as bioactive agents and environmental stresses are known to cause the activation of sphingomyelinase (SMase), which hydrolyzes sphingomyelin to generate ceramide as a second messenger playing a key role in differentiation and apoptosis in various cell types. Here we identified multiple forms of the membrane-associated neutral SMase (N-mSMase) activity in bovine brain. They could be classified into two groups according to extracting agents: group T-mSMase, extracted with 0.2% Triton X-100, and group S-mSMase, extracted with 0.5 M (NH(4))(2)SO(4). Group T-mSMase: alpha, beta, gamma, and delta, which were extensively purified from 40,000-g pellets of bovine brain homogenates by 3,150-, 5,275-, 1,665-, and 2,556-fold over the membrane extracts, respectively, by sequential use of several column chromatographies. On the other hand, S-mSMase was eluted as two active peaks of S-mSMase epsilon and zeta in a phenyl-5PW hydrophobic HPLC column and further purified by 1,119- and 976-fold over 40,000-g pellets of the homogenates, respectively. These highly purified N-mSMase enzyme preparations migrated as several bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and showed many different features in biochemical properties such as pH dependence, Mg(2+) requirements, and effects of detergents. Taken together, our data strongly suggest that mammalian brain N-mSMase may exist as multiple forms different in both its chromatographic profiles and biochemical properties.

Ammonium Sulfate↗
PubMed2000

Association between hepatitis B virus infection and HLA-DR type in Korea.

Although the mechanism of susceptibility to chronic persistent hepatitis B virus (HBV) infection is not well clarified, immunogenetic factors of the host may have a role. Recently, a strong association between HLA-DR13 and the self-limited course of HBV infection has been reported. To determine whether the elimination of HBV is related to a particular HLA allele, we studied the HBV markers and HLA-DR phenotypes of 1,272 Koreans who had visited Yonsei University Medical Center for renal transplantation. They included 330 renal transplant donors. Subjects were categorized into 3 different groups: the "Unexposed Group" (UE; n = 946) with negative HBV markers, the "Chronic Carrier Group" (CC; n = 83), who were hepatitis B surface antigen (HBsAg)-positive, and the "Spontaneously Cleared Group" (SC; n = 243), who were HBsAg-negative with antibodies to HBsAg (anti-HBs) and hepatitis B core antigen (anti-HBc). HLA-DR4 was the most common type in all groups. HLA-DR6 was significantly more frequent in 69 of 243 subjects with SC (28. 4%) than in 8 of 83 subjects with CC (9.6%) (P <.001; relative risk [RR] = 3.72). HLA-DR9 was significantly more frequent in CC than in SC (P <.001; RR = 0.33). HLA-DR13 showed a stronger association with the clearance of HBV than the other HLA-DR6 subgroup. The distribution of HLA-DR phenotypes was similar regardless of renal disease. Our data indicate that HLA-DR6, especially HLA-DR13, is one of the host factors, which influences the immune response to HBV, and may be associated with self-elimination of HBV in Koreans.

Adult↗
PubMed2000

General pharmacology of the new antiviral agent SK 1899.

The general pharmacological properties of 2-amino-9-(3-acetoxymethyl-4-isopropoxycarbonyloxybut-1-yl)purine (CAS 247081-81-8, SK 1899), a new potential antiviral agent, were investigated in mice, rats, guinea pigs, rabbits, and dogs. The oral administration of 50, 150, and 500 mg/kg of SK 1899 had no effects on the central nervous system except that it slightly increased the spontaneous locomotor activity in mice at a dose of 500 mg/kg. SK 1899 did not disturb either the spontaneous motility or contractor-induced contraction of the isolated organs such as guinea pig ileum, rat uterus, guinea pig vas deferens, and guinea pig trachea at concentrations up to 10(-4) mol/l. It slightly increased the contractile force in the isolated guinea pig atrium at a concentration of 10(-4) mol/l. Following intravenous infusion of 5, 15, and 50 mg/kg of SK 1899 to anesthetized dogs, it did not change the mean arterial pressure, heart rate, left ventricular systolic pressure (LVSP), and respiratory rate, while it slightly increased the left ventricular positive dP/dtmax (LV + dP/dtmax) at a dose of 50 mg/kg. SK 1899 did not induce any significant changes in the intestinal charcoal meal transit in mice, basal gastric juice secretion in rats, and renal function in rats. It did not affect the blood coagulation system and phenolsulfonphthalein secretion in rats. These findings suggest that SK 1899 has a very low potential to induce any adverse pharmacological effects at the doses showing antiviral activity.

Animals↗
PubMed2000

Bronchoalveolar lavage cellular composition in acute asthma and acute bronchiolitis.

OBJECTIVE: To compare cellular inflammation in the airways between acute bronchiolitis and asthma. STUDY DESIGN: Using a bronchoalveolar lavage with flexible bronchoscopy procedure, we investigated the cellular constituents of BAL fluid in children with acute exacerbation of asthma (n = 18) and infants with acute bronchiolitis caused by respiratory syncytial virus (n = 20). These results were compared with those of healthy control subjects (n = 14). RESULTS: Total lavage fluid recovered was similar in all groups. The total cell numbers were highest in the bronchiolitis group. The BAL cellular profile in the asthma group was characterized by a higher median (interquartile range) ratio of eosinophils (2.4% [1.6%-9.5%]; P <.01) than in the bronchiolitis group (0% [0%-0%]) or the control group (0% [0%-0%]). Neutrophil ratio was higher in the bronchiolitis group (40.0% [26.5%-50.0%]; P <.01), with no difference found between the asthma group (3.3% [2.0%-7.9%]) and the control group (2.0% [0.8%-5.5%]). CONCLUSIONS: Asthma and acute bronchiolitis are characterized by an elevated cellular percentage of eosinophils and neutrophils, respectively, in bronchoalveolar lavage fluid.

Acute Disease↗
PubMed2000

Secretion of CXC chemokine IP-10 by peripheral blood mononuclear cells from healthy donors and breast cancer patients stimulated with HER-2 peptides.

CXC chemokines play an important role in recruitment of T cells to the site of activation and regulation of angiogenesis. CXC chemokines are secreted by T cells stimulated with cytokines or by established cytotoxic T lymphocyte (CTL) lines at recognition of conventional antigen (Ag), but the activation requirements and the relationship of interferon-gamma (IFN-gamma) inducible protein (IP-10) secretion with IFN-gamma induction in lymphocytes are still unclear. We studied the induction of IP-10 from nonadherent peripheral blood mononuclear cells (PBMC) by IFN-gamma, interleukin-12 (IL-12), and the HER-2 peptide E75, which forms a CTL-defined antigen. We found that IFN-gamma alone was a weak inducer of IP-10 in these cells, whereas IL-12 was a significantly stronger inducer of IP-10. In the presence of IL-12, the tumor peptide E75 (HER-2, 369-377) was a stronger inducer of IP-10 than was IL-12 alone. E75 and its variants mutated at position 5 could also induce IP-10 in the absence of exogenous IL-12 or IFN-gamma. IP-10 induction by E75 required HLA-A2 presentation and B7-CD28 interactions and was partially inhibited by blocking of CD40-CD40L interactions. These results indicate that presentation of tumor peptides to peripheral T cells can induce a fast chemokine response, which in its early phase may be higher than the IFN-gamma response. This shows that the IP-10 response was independent of any early-phase IFN-gamma response in peripheral T cells. This may be important for understanding the regulation of the balance between chemoattractant chemokines (CC) and CXC chemokines by tumor Ag and may have implications for understanding the mechanisms of polarization of T cells and conditioning of antigen-presenting cells (APC) by tumor antigens.

Breast Neoplasms↗