Biomedical subjects

Young Sun Kim

Publications and source records attributed to Young Sun Kim.

13 recordsLinked to original sources

PubMed2006

Methodology of the thyroid gland disease decision-making using profiling in steroid hormone pathway.

To find out the genetic factors of outbreak of thyroid gland disease, we developed the thyroid gland decision-making system, which processes the metabolic profile in steroid hormone map using a statistical method. Metabolic profile is a measured data of lots of mixed materials that includes not only known metabolites, but also unknown ones, which is estimated to have an influence on the thyroid gland disease. Therefore, to develop thyroid gland disease decision-making system, analyzing metabolic profile containing multi-materials would be useful for diagnosing thyroid gland disease. Because experimental values used for system construction are area values for the retention time, the observations are preprocessed through variable transition and t-test to use the area values concurrently and the highly correlated materials are estimated by principal component analysis. The thyroid gland decision-making system developed through the logistic regression is an excellent system demonstrating 98.7% accuracy in the classification table.

Algorithms↗

PubMed2006

Down syndrome candidate region 1 increases the stability of the IkappaBalpha protein: implications for its anti-inflammatory effects.

Down syndrome candidate region 1 (DSCR1), an endogenous inhibitor of calcineurin, inhibits the expression of genes involved in the inflammatory response. To elucidate the molecular basis of these anti-inflammatory effects, we analyzed the role of DSCR1 in the regulation of NF-kappaB transactivation using glioblastoma cells stably transfected with DSCR1.4 or its truncation mutants (DSCR1.4-(1-133) and DSCR1.4-(134-197)). Overexpression of DSCR1.4 significantly attenuated the induction of cyclooxygenase-2 (COX-2) expression by phorbol 12-myristate 13-acetate (PMA) via a calcineurin-independent mechanism. Experiments using inhibitors of the signaling molecules for NF-kappaB activation showed that NF-kappaB is responsible for the induction of COX-2. Full-length and truncated DSCR1.4 decreased the steady-state activity of NF-kappaB as well as PMA-induced activation of NF-kappaB, which correlated with attenuation of COX-2 induction. DSCR1.4 did not affect the PMA-stimulated phosphorylation or degradation kinetics of IkappaBalpha; however, DSCR1.4 significantly decreased the basal turnover rate of IkappaBalpha and consequently up-regulated its steady-state level. In the same context, knockdown of endogenous DSCR1.4 increased the turnover rate of IkappaBalpha as well as COX-2 induction. These results suggest that DSCR1 attenuates NF-kappaB-mediated transcriptional activation by stabilizing its inhibitory protein, IkappaBalpha.

Anti-Inflammatory Agents↗

PubMed2006

Fluorimetric determination of cerium(IV) with ascorbic acid.

A simple, sensitive, and selective method for the determination of cerium(IV), based on the oxidative reaction between cerium(IV) and ascorbic acid, has been described. The fluorescence comes from Ce(III) at lambda(excitation) 298 nm and lambda(emission) 358 nm, which, in turn, is obtained from the oxidation of ascorbic acid by Ce(IV) in the presence of sulfuric acid. The optimum conditions such as concentrations of ascorbic acid, sulfuric acid media and pH of the buffer solution were investigated. The fluorescent intensity of the system is linear over the range 0.0531 microg/ml to 0.3322 mg/ml Ce(IV) and detection limit and correlation coefficient are 0.0145 microg/ml and R=0.99987, respectively.

Journal Article↗

PubMed2006

Expression of peroxiredoxin and thioredoxin in human lung cancer and paired normal lung.

BACKGROUND: Peroxiredoxins (Prxs) have been implicated in regulating many cellular processes including cell proliferation, differentiation and apoptosis. However, the pathophysiological significance of Prx proteins, especially in lung disease, has not been defined. Therefore, the authors investigated the distribution and expression of various Prx isoforms in lung cancer and compared this with normal lung from human and mouse. METHODS: Patients diagnosed with lung cancer who underwent surgery at Ajou Medical Center were enrolled. Expression of Prxs, thioredoxin and thioredoxin reductase was analysed by proteomic techniques. Immunohistochemistry was performed to localize Prx proteins. RESULTS: Immunohistochemical staining showed that the isoforms of Prx I, II, III and V were predominantly expressed in bronchial and alveolar epithelium as well as in alveolar macrophages of the normal mouse lung. The isoforms I, III and thioredoxin were overexpressed in lung cancer tissues compared with normal lungs. There was also an increased amount of oxidized form of Prx I and a putative truncated form of Prx III in lung cancer samples when analysed on two-dimensional electrophoresis. In addition, a 40-kDa intermediate MW protein band and high MW bands of over 20 kDa, recognized by anti-Prx (a-Prx) I antibody, were present in tissue extracts of lung cancer patients on one-dimensional electrophoresis. CONCLUSION: The upregulation of Prx I, Prx III and thioredoxin in lung cancer tissue may represent an attempt by tumour cells to adjust to the microenvironment in a manner that is advantageous to survival and proliferation.

Adenocarcinoma↗

PubMed2005

Is cytokeratin immunoreactivity useful in the diagnosis of short-segment Barrett's oesophagus in Korea?

BACKGROUND: Cytokeratin 7/20 staining has been reported to be helpful in diagnosing Barrett's oesophagus and gastric intestinal metaplasia. However, this is still a matter of some controversy. OBJECTIVE: To determine the diagnostic usefulness of cytokeratin 7/20 immunostaining for short-segment Barrett's oesophagus in Korea. METHODS: In patients with Barrett's oesophagus, diagnosed endoscopically, at least two biopsy specimens were taken from just below the squamocolumnar junction. If goblet cells were found histologically with alcian blue staining, cytokeratin 7/20 immunohistochemical stains were performed. Intestinal metaplasia at the cardia was diagnosed whenever biopsy specimens taken from within 2 cm below the oesophagogastric junction revealed intestinal metaplasia. Barrett's cytokeratin 7/20 pattern was defined as cytokeratin 20 positivity in only the superficial gland, combined with cytokeratin 7 positivity in both the superficial and deep glands. RESULTS: Barrett's cytokeratin 7/20 pattern was observed in 28 out of 36 cases (77.8%) with short-segment Barrett's oesophagus, 11 out of 28 cases (39.3%) with intestinal metaplasia at the cardia, and nine out of 61 cases (14.8%) with gastric intestinal metaplasia. The sensitivity and specificity of Barrett's cytokeratin 7/20 pattern were 77.8 and 77.5%, respectively. CONCLUSION: Barrett's cytokeratin 7/20 pattern can be a useful marker for the diagnosis of short-segment Barrett's oesophagus, although the false positive or false negative rate is approximately 25%.

Adult↗

PubMed2005

Prevalence of Barrett's esophagus in Korea.

BACKGROUND: In contrast to Western countries, the prevalence of Barrett's esophagus (BE) is still believed to be very low in the Far East. The aim of the present paper was to assess the prevalence of BE in Korea. METHODS: Nine hundred and ninety-two consecutive patients undergoing their first diagnostic upper gastrointestinal endoscopies due to various indications were included from four university hospitals in Korea. Esophagus of each patient was examined during insertion of the endoscope with minimum air inflation. From subjects who were found, during endoscopy, to have columnar-lined esophagus, at least two biopsy samples were taken from the columnar epithelium. Patients exhibiting specialized columnar epithelium on histological examination were diagnosed as having BE. RESULTS: Among 992 patients, 108 cases (10.9%) were endoscopically diagnosed as short-segment BE, and three cases (0.3%) were endoscopically diagnosed as long-segment BE. However, only 36 patients (3.6%) met the histological criteria for BE. Among these patients, only one (0.1%) was histologically diagnosed as having long-segment BE. Reflux esophagitis, mostly in a mild degree, was found in 25.0% of the BE group, and 8.6% of the non-BE group (P = 0.0022). Hiatal hernias were more commonly found in the BE group than in the non-BE group (22.2% vs 8.9%, P = 0.0163). CONCLUSIONS: Although the prevalence of BE in Korea appears to be lower than the reported rates from Western countries, it may not be as low as was previously thought.

Barrett Esophagus↗

PubMed2004

Clinical significance of variceal hemorrhage in recent years in patients with liver cirrhosis and esophageal varices.

BACKGROUND AND AIMS: Recent progress in the treatment of variceal bleeding might have reduced the impact of variceal bleeding on survival in patients with esophageal varices. We conducted a retrospective cohort study in an attempt to re-evaluate the clinical significance of variceal bleeding. METHODS: A cohort of 304 patients with liver cirrhosis and esophageal varices, who had no previous history of variceal bleeding and no prophylactic therapy, was studied. RESULTS: During a median follow-up period of 32 months, 55 patients (18%) bled from varices and 111 (37%) died. Variceal hemorrhages accounted for 15% of total deaths. The mortality of first variceal bleeding was 25% in the whole group, but was remarkably different depending on liver function at the time of bleeding (0% in grade Child A vs 55% in grade C; P < 0.05). Among the survivors of first bleeding, 30% experienced rebleeding. Form of varix, red color sign and heavy drinking were the independent risk factors for first variceal bleeding. Multivariate analysis revealed that variceal bleeding still had a significant (P < 0.001) impact on death in the whole cohort, when other independent prognostic factors such as age, ascites, encephalopathy, platelet count, serum albumin level and hepatocellular carcinoma were adjusted. Furthermore, in subgroup analyses, variceal bleeding was more strongly (P < 0.001) linked to death in patients with alcoholic cirrhosis than in those with non-alcoholic cirrhosis, and showed a significant association with survival only for the patients in Child grade B. CONCLUSIONS: Variceal bleeding has various prognostic impacts depending on the etiology of cirrhosis or on the degree of liver dysfunction, and this needs to be taken into account in the prophylaxis against first variceal bleeding.

Adult↗

PubMed2003

Screening test data analysis for liver disease prediction model using growth curve.

This study was done based on screening test data accumulated from 1994 to 2001 for studying of risk factor related with liver disease and prediction model of liver disease. In the existing study related with liver, the main current is studying on liver cancer, not on liver disease, previous step into liver cancer. As a result of estimating prediction model through the risk factors of liver disease and the growth curve on the basis of data, it is shown that most of the risk factors about liver disease are also those about known well as liver cancer. In addition, to investigate liver disease prevalence from the viewpoint of the future, this study presumed risk factor through the various growth curve analysis and examined logistic regression, decision tree and neural network from those estimators. In the case of neural network using growth curve estimator of Xi(5)=alphai+betaiT+epsiloniT, accuracy of liver disease was 72.55% and sensitivity was 78.62%. On the other hand, in the case of liver disease prediction model using recent screening test data estimator, accuracy was 72.09% and sensitivity was 71.72%. Those are lower than liver disease prediction model of growth curve analysis. In the various liver disease prediction models assumed by growth curve and many distinction models, when growth curve estimator was used, sensitivity value was improved.

Humans↗

PubMed2003

G2 checkpoint in uterine cervical cancer with HPV 16 E6 according to p53 polymorphism and its screening value.

INTRODUCTION: We aimed to verify not only whether homozygous Arg at codon 72 of the p53 apoptotic domain is a possible risk factor for cervical human papillomavirus (HPV)-related cancer, but whether degraded p53 may have an effect on a G2 checkpoint of the cell cycle. The implication of the codon 72 polymorphism of p53 in cervical tumor remains controversial. Furthermore, G2 checkpoint alteration and its relationship with p53, the codon 72 allotype, according to HPV infection in cervical tumors, has not been studied. MATERIALS AND METHODS: The purified genomic DNA from 252 archival cervical tissues [102 cervical intraepithelial neoplasias (CINs) and 46 squamous cell carcinomas of the uterine cervix (SCCs), and 104 normal] were amplified by nested polymerase chain reaction (PCR) for HPV-16/HPV-18. In addition, all of them were amplified by PCR for exon 4 of p53, where the codon 72 resides. The amplified PCR products were then sequenced using the forward primer. A polymorphism analysis was done by SnaPshot ddNTP primer extension and following direct sequencing. The reaction mixture was treated with 0.25 unit of shrimp alkaline phosphatase (Amersham) at 37 degrees C for 1 h, subsequently performed in an ABI Prism 310 Genetic Analyzer (Perkin-Elmer). The archival slides were incubated overnight at 4 degrees C using mouse anti-human recombinant cyclin B1 polyclonal antibody or mouse anti-Xenopus p34(cdc2) monoclonal antibody for immunohistochemistry (Santa Cruz Biotech, Santa Cruz, CA). RESULTS: The frequency of Arg allelic homozygosity was high in both cases (89.1%) and the control (80.8%) group (P = 0.4703). All groups except CIN were in Hardy-Weinberg equilibrium. There was no significant difference in the frequency of p53 polymorphism between the HPV-positive (Arg, 88.0%) and the negative (Arg, 88.8%) groups, or between CIN (Arg, 88.2%) and SCC (Arg, 89.1%). Both immunoreactivities to cyclin B and p34(cdc2) were strongly correlated with the HPV infection (P = 0.0001) and the histological types (P = 0.0001) between CIN and SCC, being strongly correlated with each other (alpha:0.62954, P = 0.0001). CONCLUSION: The particular type of the p53 polymorphism does not bear relation to the progression of cervical cancer, HPV infection, or to the p53 codon 72 polymorphism. However, the G2 checkpoint appears to be altered in the case of a HPV-positive SCC.

Base Sequence↗

PubMed2003

The prognosis of liver cirrhosis in recent years in Korea.

The survival of a recent series of 823 cirrhosis patients who were followed up for a mean of 48 months was analyzed. Cirrhosis was ascribed to alcohol (26%), hepatitis virus B (58%), hepatitis virus C (11%) or both (2%), or was cryptogenic (3%). Features of decompensation were observed in 51% of the patients at entry, and newly developed in 44% of compensated patients within 5 yr. The 5-yr survival after decompensation was 25%. The leading causes of death were liver failure (53%), hepatocellular carcinoma (HCC, 23%), and variceal bleeding (10%). Early detection of HCC significantly improved the survival of cirrhosis patients. Biannual ultrasonography increased the detection rate of small HCC. Mortality of variceal hemorrhage was much lower in patients with Child-Pugh scores from 5 to 8 than in those with scores above 8 (5% vs. 52%). Endoscopic prophylaxis significantly decreased the incidence of first variceal hemorrhage, but the effect was insufficient to improve the rate of survival. Mortality of first spontaneous bacterial peritonitis was 18%. These data suggest that the mortality of major complications of liver cirrhosis has considerably decreased during the last two decades, while there was no remarkable improvement in long-term survival. More efficient management of etiologic factors would be required.

Adult↗

PubMed2003

[An analysis of extravariceal collaterals of gastric varices using magnetic resonance angiography in portal hypertensive patients].

BACKGROUND/AIMS: This study was aimed to analyze the relationship between gastric varices and its collaterals using magnetic resonance angiography (MRA) and to assess the usefulness of MRA in studies of portosystemic circulation. METHODS: Eighty-one patients who had portal hypertension with gastric varices took MRA before the therapy for gastric varices. RESULTS: The types of collaterals observed by MRA were left gastric vein in 67 patients (83%), short gastric vein in 28 (35%), gastrorenal shunt in 25 (31%), and splenorenal shunt in 14 (17%). In most of patients with advanced gastric varices, the size of left gastric vein was larger than others. In most cases of large gastric varices, the short gastric vein ranged between 5 to 10 mm. Gastrorenal shunt was also correlated with the size of gastric varices. The types of more prominent esophageal varices showed a right type (left gastric vein predominance), but the types of more prominent gastric varices or only the gastric varices showed a left type (posterior or short gastric vein predominance) (p<0.05). CONCLUSIONS: Gadolinium enhanced 3D-MRA can contribute to the study of the hemodynamic relationships between gastric vein and the collateral circulations by presenting more clear images for patients with portal hypertension.

Adult↗

PubMed2002

Development of DNA chip for the simultaneous detection of various beta-lactam antibiotic-resistant genes.

A robust and fast DNA chip method was developed in order to detect the various beta-lactam antibiotic-resistance genes in one slide. These genes included PSE, OXA, FOX, MEN, CMY, TEM, SHV, OXY, and AmpC. beta-lactam antibiotic-resistance genes were labeled with a fluorescent nucleotide by a multiplex polymerase chain reaction using a mixture of specific primer sets for each gene. This labeled target was hybridized with a DNA chip that contained the spots of the specific probe DNAs for each beta-lactam antibiotic-resistance gene. This technique made it possible to detect the specific resistance gene, even in a single bacterium.

Bacteria↗

PubMed2002

Sonography of the shoulder after arthrography (arthrosonography): preliminary results.

PURPOSE: The purpose of this study was to verify whether arthrosonography improves diagnostic accuracy in diseases of the shoulder and provides additional information for therapeutic planning, compared with conventional sonography. METHODS: We prospectively studied 113 consecutive patients with chronic shoulder pain. Sonography was performed before and after arthrography, with the radiologist blinded to the results of arthrography. When a rotator cuff tear was detected sonographically, its type, location, and size were recorded; we also evaluated any changes in the subacromial-subdeltoid bursa and any abnormalities in the biceps tendon sheath. The diagnostic accuracy of conventional sonography and arthrosonography was compared with that of arthrography for rotator cuff tear. Changes in the subacromial-subdeltoid bursa and biceps tendon sheath seen on conventional sonography were also compared with those seen on arthrosonography. RESULTS: The sensitivity and specificity of conventional sonography in the diagnosis of rotator cuff tear were 86% (25/29) and 95% (80/84), respectively; for arthrosonography, the values were 97% (28/29) and 95% (80/84), respectively. The differences in sensitivity and specificity for the 2 sonographic techniques were not statistically significant (p > 0.05). The accuracy in localizing the tear was also not significantly different between the 2 sonographic techniques. Synovial proliferation was more easily detected with arthrosonography than it was with conventional sonography in the subacromial-subdeltoid bursa (p < 0.01) and in the biceps tendon sheath (p < 0.0001). CONCLUSIONS: Our preliminary results suggest that although arthrosonography was not superior to conventional sonography in the diagnosis of rotator cuff tears, it may provide a better assessment of the size of tears and additional information about synovial proliferation in the subacromial-subdeltoid bursa and the biceps tendon sheath.

Female↗