Biomedical subjects

Yong Seok Lee

Publications and source records attributed to Yong Seok Lee.

6 recordsLinked to original sources

PubMed2006

SNP@Ethnos: a database of ethnically variant single-nucleotide polymorphisms.

Inherited genetic variation plays a critical but largely uncharacterized role in human differentiation. The completion of the International HapMap Project makes it possible to identify loci that may cause human differentiation. We have devised an approach to find such ethnically variant single-nucleotide polymorphisms (ESNPs) from the genotype profile of the populations included in the International HapMap database. We selected ESNPs using the nearest shrunken centroid method (NSCM), and performed multiple tests for genetic heterogeneity and frequency spectrum on genes having ESNPs. The function and disease association of the selected SNPs were also annotated. This resulted in the identification of 100 736 SNPs that appeared uniquely in each ethnic group. Of these SNPs, 1009 were within disease-associated genes, and 85 were predicted as damaging using the Sorting Intolerant From Tolerant system. This study resulted in the creation of the SNP@Ethnos database, which is designed to make this type of detailed genetic variation approach available to a wider range of researchers. SNP@Ethnos is a public database of ESNPs with annotation information that currently contains 100 736 ESNPs from 10 138 genes, and can be accessed at http://variome.net and http://bioportal.net/ or directly at http://bioportal.kobic.re.kr/SNPatETHNIC/.

Chromosome Mapping↗

PubMed2006

Antiproliferative and apoptotic effects of zinc-citrate compound (CIZAR(R)) on human epithelial ovarian cancer cell line, OVCAR-3.

OBJECTIVE: Zinc inhibits the growth of several carcinoma cells through induction of cell cycle arrest and apoptosis. The intracellular concentration of zinc and its dynamic changes are critically important in cell biology. We investigated the effects of zinc-citrate compound (CIZAR) on normal human ovarian epithelial cells (NOSE) and human epithelial ovarian cancer cell line, OVCAR-3. METHODS: To investigate the potential effect of CIZAR on cell growth and survival, cells were treated with different doses and exposed to different times. Intracellular concentration of zinc was measured by colorimetric assay. Mitochondrial aconitase activity was determined in cell extracts using aconitase assay. The flow cytometric assay, DNA laddering, and morphological analysis were done to investigate cytotoxic effects of CIZAR. Molecular mechanism of cell death was investigated by p53, Bcl-xL, Bcl-2, Bax protein, activity of caspase-3 and -12, and activity of telomerase. RESULTS: CIZAR-induced zinc accumulation in OVCAR-3 cells was higher than that in NOSE cells. CIZAR(R) treatment resulted in a time- and dose-dependent decrease in cell number in OVCAR-3 cells in comparison with NOSE cells. M-aconitase activity was significantly decreased in OVCAR-3 cells within 4 h exposure to CIZAR but relatively constant in NOSE cells. The flow cytometric assay, DNA laddering, and morphological analysis indicated apoptosis in OVCAR-3 cells but not in NOSE cells. CIZAR increased the expression of p21(waf1) which is a part of p53-independent pathway and induced reduction of telomerase activity. CIZAR reduced expression of Bcl-2 and Bcl-xL proteins but induced expression of Bax protein. CIZAR induced apoptosis of OVCAR-3 cells by activation of caspase-12 and caspase-3 pathway. CONCLUSIONS: Exposure to CIZAR induces apoptosis in OVCAR-3 cells which accumulate high intracellular levels of zinc, but not in NOSE cells, which do not accumulate high levels of zinc. CIZAR(R) prevents the proliferation of OVCAR-3 cells by inactivation of m-aconitase activity and induces apoptosis by induction of proapoptotic gene (Bax), repression of antiapoptotic genes (Bcl-2, Bcl-xL), and consequently activation of caspase-3. CIZAR also induced activation of caspase-12. The CIZAR will offer new window in prevention and treatment of epithelial ovarian cancer.

Aconitate Hydratase↗

PubMed2005

Granulocyte colony-stimulating factor enhances angiogenesis after focal cerebral ischemia.

Granulocyte colony-stimulating factor (G-CSF) is a neuroprotective agent and activates endothelial proliferation and bone marrow stem cell mobilization. We studied the effect of G-CSF on angiogenesis and neurological recovery after focal cerebral ischemia. After the induction of transient focal ischemia in rats, G-CSF (50 micro/day, i.p.) or PBS was administered for 3 days. We evaluated the functional recovery, infarct volume, inflammatory infiltration, blood-brain barrier (BBB) disruption, hemispheric atrophy, protein expressions of endothelial nitric oxide synthase (eNOS) and angiopoietins, and the therapeutic time window of G-CSF administration. We then analyzed endothelial cell proliferation, the vascular surface area, the number of branch points, and the vascular length. G-CSF treatment improved behavioral recovery and reduced the infarct volume, the inflammatory infiltration, the BBB disruption, and the hemispheric atrophy. G-CSF injection, starting at 2 h, 1 day, or 4 days after ischemia, resulted in a better functional recovery and a greater reduction in hemispheric atrophy than injection starting at day 7. The vascular surface area, the vascular branch points, the vascular length, the number of BrdU(+) endothelial cells, and eNOS/angiopoietin-2 expression were significantly increased in the G-CSF group compared with the ischemia-only group. G-CSF injection starting at 1 day induced larger endothelial proliferation compared with injection starting at 7 days. In this study, we provide evidences that G-CSF enhances the angiogenesis and reduces the ischemic damage, which promotes the long-term functional recovery.

Angiopoietin-1↗

PubMed2005

Fluoroscopically guided balloon dilation for patients with esophageal stricture after radiation treatment.

PURPOSE: To evaluate the safety and clinical effectiveness of fluoroscopically guided balloon dilation in patients with esophageal stricture after radiation therapy (RT). MATERIALS AND METHODS: From April 1993 through December 2004, fluoroscopically guided balloon dilation was performed in 15 patients with esophageal strictures secondary to previous RT. Technical success, clinical success, recurrence of dysphagia, primary and secondary patency rates, and complications related to the procedure were retrospectively evaluated. RESULTS: Twenty-five balloon dilations were performed in 15 patients, with a mean of 1.7 dilations per patient (range, 1-5). Technical success was achieved in all procedures. One patient was immediately lost to follow-up and another underwent elective esophageal surgery 13 days after the procedure. Of the remaining 13 patients, clinical success was achieved 11 (85%). Two of 13 patients exhibited recurrence of dysphagia before 1 month after balloon dilation. Among the 11 patients in whom clinical success was achieved, seven exhibited maintained initial improvement of dysphagia until their last follow-up (mean, 174 days) and four exhibited recurrence of dysphagia after the first balloon dilation. Dysphagia recurred 2-128 days (mean, 67.2 d) after the first balloon dilation in six of the 13 patients (46%), who underwent further balloon dilation and/or stent placement. The primary and secondary patency rates at 1, 3, and 6 months were 86%, 68%, and 47% and 100%, 92%, and 62%, respectively. There were no major complications. Type 1 and 2 esophageal ruptures occurred after 12 dilations in nine patients; they were treated conservatively. CONCLUSION: Fluoroscopically guided balloon dilation for esophageal stricture after RT can be safe and effective. However, the high rate of recurrent dysphagia requires repeated dilations.

Adult↗

PubMed2005

Synergistic effect between catechin and ciprofloxacin on chronic bacterial prostatitis rat model.

BACKGROUND: Chronic bacterial prostatitis (CBP) is the most common urological disease in adult men. Antibiotic therapy is the gold standard of treatment. However, long-term therapy resulted in many side-effects and bacterial resistance. Because of these reasons, we need new treatment modality that could replace traditional antibiotic therapy. Catechin, an extract of green tea, has antimicrobial effect against various bacteria and synergy effect to antibiotics. We evaluate the synergistic effects of catechin on the treatment of CBP in an animal model. METHODS: An experimental CBP model was induced in 70 male Wistar rats by instillation of 0.2 mL bacterial suspension (E-coli Z17, O2:K1:H-) containing 1 x 10(8) CFU/mL into the prostatic urethra. Microbiologically and histologically proven CBP model was demonstrated in 58.6% (41 of 70) of the rats after 4 weeks of bacterial instillation. The 41 rats demonstrating CBP were randomly divided into four groups; the control, catechin, ciprofloxacin and catechin with ciprofloxacin groups. All drug treatments were conducted over a period of 2 weeks. After treatment, the results were analyzed with microbiological cultures and histological findings of the prostate and urine samples to compare each group. RESULTS: Microbiological cultures and histological findings of the prostate and urine samples demonstrated reduced bacterial growth and improved inflammatory responses in all three experimental groups compared with the control group. The catechin group showed coherent trends of decrease in bacterial growth and improvements in prostatic inflammation compared with the control group, but not to a statistically significant degree (P > 0.05). However, the ciprofloxacin and catechin with ciprofloxacin groups showed statistically significant decreases in bacterial growth and improvements in prostatic inflammation compared with the control group (P < 0.05). The catechin with ciprofloxacin group showed a statistically significant decrease in bacterial growth and improvements in prostatic inflammation compared with the ciprofloxacin group (P < 0.05). CONCLUSIONS: These results suggest that catechin may be an effective material in CBP treatment. Particularly, combination treatment of catechin and ciprofloxacin has synergistic effect. Therefore, we suggest that the combination of catechin and ciprofloxacin may be effective in treating CBP with a higher success rate.

Animals↗

PubMed2003

Alteration of sexual function after classic intrafascial supracervical hysterectomy and total hysterectomy.

STUDY OBJECTIVE: To investigate possible advantages of classic intrafascial supracervical hysterectomy (CISH) over total hysterectomy with respect to sexual function. DESIGN: Retrospective study (Canadian Task Force classification II-2). SETTING: Department of obstetrics and gynecology at a university teaching hospital. PATIENTS: One hundred eight women who had undergone CISH and 125 who had total hysterectomy. INTERVENTION: A standard questionnaire sent to all 233 patients a minimum of 12 and maximum of 24 months after hysterectomy. MEASUREMENTS AND MAIN RESULTS: Data obtained on sexual function were classified by changes (improved, no change, deteriorated) before and after hysterectomy. No significant difference was found between groups in mean time interval between surgery and first intercourse. Overall, over two-thirds of women experienced either no change or improvement in sexual function regardless of which procedure was performed, with no statistically significant differences in changes in libido, frequency of coitus, frequency of orgasm, and degree of orgasm. CONCLUSIONS: Women who underwent CISH and total hysterectomy had no statistically significant differences with regard to postoperative sexual function.

Adult↗