Showing papers by "Sungkyunkwan University published in 2003"

The Metabolic Syndrome: Prevalence and Associated Risk Factor Findings in the US Population From the Third National Health and Nutrition Examination Survey, 1988-1994

Abstract: Coronary heart disease (CHD) is the leading cause of death in the United States.1 Factors associated with an increased risk of developing CHD that tend to cluster in individuals include older age, high blood pressure, a low level of high-density lipoprotein (HDL) cholesterol, a high triglyceride level, a high plasma glucose concentration, and obesity.2 These associated risk factors have been called syndrome X,3 the insulin resistance syndrome,4 or the metabolic syndrome.5 The mechanisms underlying the metabolic syndrome are not fully known; however, resistance to insulin-stimulated glucose uptake seems to modify biochemical responses in a way that predisposes to metabolic risk factors.3,6,7 Insulin resistance is thought to be primarily due to obesity or an inherited genetic defect.8 As the prevalence of obesity increases in the United States, the prevalence of the metabolic syndrome may be expected to increase markedly. Estimates of the prevalence of the metabolic syndrome have varied substantially in part because of the variability of evaluated populations and of diagnostic criteria.9 The recent Third Report of the National Cholesterol Education Program Adult Treatment Panel (ATP III) included clinical diagnosis guidelines for the metabolic syndrome.10 Compared with findings from earlier studies3-5 and World Health Organization guidelines, the new ATP III defines criteria readily measured in clinical practice. These consensus-generated guidelines provide the opportunity to assess the overall prevalence of the metabolic syndrome in the US population according to an accepted standard definition. In an initial study, Ford et al11 reported un-adjusted and age-adjusted metabolic syndrome prevalences of 21.8% and 23.7%, respectively, for the US population. The objectives of this study are to examine the prevalence of the metabolic syndrome by ethnicity, age, body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters), socioeconomic status, and lifestyle factors.

Observation of a Narrow Charmoniumlike State in Exclusive B±→K±π+π-J/ψ Decays

Abstract: We report the observation of a narrow charmoniumlike state produced in the exclusive decay process B+/--->K+/-pi(+)pi(-)J/psi. This state, which decays into pi(+)pi(-)J/psi, has a mass of 3872.0+/-0.6(stat)+/-0.5(syst) MeV, a value that is very near the M(D0)+M(D(*0)) mass threshold. The results are based on an analysis of 152M B-Bmacr; events collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider. The signal has a statistical significance that is in excess of 10sigma.

Texture-based approach for text detection in images using support vector machines and continuously adaptive mean shift algorithm

Abstract: The current paper presents a novel texture-based method for detecting texts in images. A support vector machine (SVM) is used to analyze the textural properties of texts. No external texture feature extraction module is used, but rather the intensities of the raw pixels that make up the textural pattern are fed directly to the SVM, which works well even in high-dimensional spaces. Next, text regions are identified by applying a continuously adaptive mean shift algorithm (CAMSHIFT) to the results of the texture analysis. The combination of CAMSHIFT and SVMs produces both robust and efficient text detection, as time-consuming texture analyses for less relevant pixels are restricted, leaving only a small part of the input image to be texture-analyzed.

Epidemiology of inflammatory bowel disease in the Songpa-Kangdong district, Seoul, Korea, 1986-2005: a KASID study.

Abstract: Background: Crohn's disease (CD) and ulcerative colitis (UC) are considered rare diseases in developing countries. We have evaluated the incidence and prevalence of CD and UC over time in a district of Seoul, Korea. Methods: A population-based study was performed from 1986 to 2005 in the Songpa-Kangdong district of Seoul. To recruit patients as completely as possible, multiple information sources, including all medical facilities in the study area and 3 referral centers nearby but outside the study area, were used. Results: During the 20-year study period, 138 incident cases of CD (102 men, 36 women) and 341 incident cases of UC (170 men, 171 women) were identified. For the 20-year period, the adjusted mean annual incidence rates of CD and UC per 100,000 inhabitants were 0.53 (95% CI 0.44–0.62) and 1.51 (95% CI 1.34–1.67), respectively. When analyzed by 5-year intervals, the mean annual incidence rates of CD and UC increased significantly, from 0.05 and 0.34 per 100,000 inhabitants, respectively, in 1986–1990 to 1.34 and 3.08 per 100,000 inhabitants, respectively, in 2001–2005. The adjusted prevalence rates of CD and UC per 100,000 inhabitants on December 31, 2005, were 11.24 (95% CI 9.29–13.18) and 30.87 (95% CI 27.47–34.27), respectively. Conclusions: The incidence and prevalence of CD and UC in Seoul, Korea, are still low compared with those in Western countries, but are rapidly increasing. (Inflamm Bowel Dis 2007)

Observation of the DsJ(2317) and DsJ(2457) in B Decays

Abstract: We report the first observation of the B-->(D) over barD(sJ)(2317) and B-->(D) over barD(sJ)(2457) decays based on 123.8x10(6) B (B) over bar events collected with the Belle detector at KEKB. We observe the D-sJ(2317) decay to D(s)pi(0) and the D-sJ(2457) decay to the D(s)(*)pi(0) and D(s)gamma final states. We also set 90% C.L. upper limits for the decays D-sJ(2317)-->D-s*gamma, D-sJ(2457)-->D-s*gamma, D-sJ(2457)-->D(s)pi(0), and D-sJ(2457)-->D(s)pi(+)pi(-).

Major Complications after Radio-frequency Thermal Ablation of Hepatic Tumors: Spectrum of Imaging Findings

Abstract: Although radio-frequency (RF) ablation has been accepted as a promising and safe technique for treatment of unresectable hepatic tumors, investigation of its complications has been limited. According to the multicenter (1,139 patients in 11 institutions) survey data of the Korean Study Group of Radiofrequency Ablation, a spectrum of complications occurred after RF ablation of hepatic tumors. The prevalence of major complications was 2.43%. The most common complications were hepatic abscess (0.66%), peritoneal hemorrhage (0.46%), biloma (0.20%), ground pad burn (0.20%), pneumothorax (0.20%), and vasovagal reflex (0.13%). Other complications were biliary stricture, diaphragmatic injury, gastric ulcer, hemothorax, hepatic failure, hepatic infarction, renal infarction, sepsis, and transient ischemic attack. One procedure-related death (0.09%) occurred (due to peritoneal hemorrhage). Three important strategies for decreasing the rate of complications are prevention, early detection, and proper management. A ph...

Measurement of Branching Fractions for B→ηcK(*) Decays

Abstract: We report measurements of branching fractions for charged and neutral $B\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c}K$ decays where the ${\ensuremath{\eta}}_{c}$ meson is reconstructed in the ${K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}$, ${K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$, ${K}^{*0}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, and $p\overline{p}$ decay channels. The neutral ${B}^{0}$ channel is a $CP$ eigenstate and can be used to measure the $CP$ violation parameter $\mathrm{sin} 2{\ensuremath{\varphi}}_{1}$. We also report the first observation of the ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c}{K}^{*0}$ mode. The results are based on an analysis of $29.1\text{ }{\mathrm{f}\mathrm{b}}^{\ensuremath{-}1}$ of data collected by the Belle detector at KEKB.

Constitutive phosphorylation of Akt/PKB protein in acute myeloid leukemia: its significance as a prognostic variable.

Abstract: Constitutive phosphorylation of Akt/PKB protein in acute myeloid leukemia: its significance as a prognostic variable

Hydrocarbon production from secondarily treated piggery wastewater by the green alga Botryococcus braunii

Abstract: A laboratory study was conducted on the removal of nitrogen and phosphorus from piggery wastewater during growth of Botryococcus braunii UTEX 572, together with measurements of hydrocarbon formation by the alga. The influence was tested of the initial nitrogen and phosphorus concentration on the optimum concentration range for a culture in secondarily treated piggery wastewater. A high cell density (> 7 g L−1 d. wt) was obtained with 510 mg L−1 NO3-N. Growth increased with nitrogen concentration at the basal phosphorus concentration (14 mg P L−1). The growth rate was nearly independent (μ = 0.027 ∼ 0.030 h−1) of the initial phosphate concentration, except under conditions of phosphate deficiency (μ = 0.019 h−1). B. braunii grew well in piggery wastewater pretreated by a membrane bioreactor (MBR) with acidogenic fermentation. A dry cell weight of 8.5 mgL−1 and hydrocarbon level of 0.95 gL−1 were obtained, and nitrate was removed at a rate of 620 mg NL−1. These results indicate that pretreated piggery wastewater provides a good culture medium for the growth and hydrocarbon production by B. braunii.

Measuring Response in Solid Tumors: Comparison of RECIST and WHO Response Criteria

Abstract: Background Objective tumor response is a common endpoint in daily practice as well as in clinical trials to evaluate the efficacy of anti-cancer agents. Traditionally, the standard World Health Organization (WHO) criteria has been adopted in these contexts. However, the recent development of new classes of anti-cancer agents and progress in imaging technology have required new methodology to evaluate response to treatment. Recently, the Response Evaluation Criteria in Solid Tumors Group (RECIST) proposed new guidelines using unidimensional measurement. Theoretically, the simple sum of the maximum diameters of individual tumors is more linearly related to cell kill than is the sum of the bidimensional products. To validate these new guidelines, we have compared the standard WHO response criteria with the new RECIST guidelines in the same patient population. Methods Data from 79 patients enrolled in eight prospective phase II studies at Samsung Medical Center were retrospectively re-analyzed to determine the concordance between the two response criteria. The two response criteria were applied separately, and the results were compared using the kappa statistic to test concordance for overall response rate. Results The overall response rate according to the WHO criteria was 31.6%. Using the RECIST criteria, nine patients were reclassified and the overall response rate was 30.4%. There was excellent agreement between the unidimensional and bidimensional criteria in 23 of 25 responses (92%). The kappa statistic for concordance for overall response was 0.91. Conclusions We conclude that the new RECIST guidelines are comparable to the old response criteria in evaluating response in solid tumors. Moreover, the new guidelines are just as simple and reproducible in the measurement of response in daily practice as they are in clinical trials.

Metastasis to regional lymph nodes in patients with esophageal squamous cell carcinoma: CT versus FDG PET for presurgical detection prospective study.

Abstract: PURPOSE: To prospectively compare the accuracy of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) for detection of primary tumor and metastasis to individual lymph node groups and for nodal staging. MATERIALS AND METHODS: From February 2000 to July 2001, 81 patients with squamous cell carcinoma of the esophagus (78 men and three women; age range, 31–90 years; mean age, 63 years) underwent CT and FDG PET before esophagectomy and lymph node dissection. During surgery, all visible and palpable lymph nodes in the surgical fields were removed. The accuracies of CT and FDG PET for depiction of metastasis to lymph nodes were compared. RESULTS: For depiction of malignant nodal groups in each lymph node group, the sensitivity, specificity, and accuracy, respectively, of CT were 11% (11 of 96 nodal groups), 95% (553 of 581), and 83% (564 of 677), whereas those of FDG PET were 30% (29 of 96), 90% (525 of 581), and 82% (554 of 677) (P values: <.001, .009, and .382,...

Magnetism in all-carbon nanostructures with negative Gaussian curvature.

Abstract: We apply the ab initio spin density functional theory to study magnetism in all-carbon nanostructures. We find that particular systems, which are related to schwarzite and contain no undercoordinated carbon atoms, carry a net magnetic moment in the ground state. We postulate that, in this and other nonalternant aromatic systems with negative Gaussian curvature, unpaired spins can be introduced by sterically protected carbon radicals.

The improvement of mechanical properties of friction-stir-welded A356 Al alloy

Abstract: The joint characteristics of friction-stir-welded A356 alloys, especially concerning the improvement of mechanical properties at the weld zone, were observed with various FSW (friction stir welding) speeds. The microstructures of the weld zone are composed of SZ (stir zone), TMAZ (thermo-mechanical affected zone) and BM (base metal). The BM shows the hypoeutectic Al–Si dendrite structure. The microstructure of the SZ is very different from that of the BM. The eutectic Si particles are dispersed homogeneously in primary Al solid solution. TMAZ, where the original microstructure was greatly deformed, is characterized by dispersed eutectic Si particles aligned along the rotational direction of the welding tool. These regions are mainly formed at the advancing side and the upper region of the retreating side. The mechanical properties of the weld zone are greatly improved in comparison to that of the BM. The hardness of the weld zone shows more uniform distribution than that of the BM because some defects are remarkably reduced and the eutectic Si particles are dispersed over the SZ. The tensile strength of the SZ is also greatly elevated and shows over 178 MPa, i.e. almost 120% that of the BM. Therefore, the FSW is well applied to the joining of the cast Al alloys.

Thrombotic and nonthrombotic pulmonary arterial embolism: spectrum of imaging findings.

Abstract: Along with clinical examination and laboratory tests, imaging plays a key role in the diagnosis of pulmonary embolism Multi-detector row helical computed tomography (CT) is particularly helpful in the diagnosis of acute pulmonary thromboembolism (PTE) owing to its capacity to directly show emboli as intravascular filling defects Although parenchymal abnormalities at CT are nonspecific for acute PTE, they may contribute to a correct diagnosis of chronic PTE, the characteristic helical CT features of which are similar to its angiographic features and include webs or bands, intimal irregularities, abrupt narrowing or complete obstruction of the pulmonary arteries, and "pouching defect" Nonthrombotic pulmonary embolism is an uncommon condition but is sometimes associated with specific imaging findings, including discrete nodules with cavitation (septic embolism), widespread homogeneous and heterogeneous areas of increased opacity or attenuation that typically appear 12-24 hours after trauma (fat embolism), and fine miliary nodules that subsequently coalesce into large areas of increased opacity or attenuation (talcosis) Knowledge of appropriate imaging methods and familiarity with the specific imaging features of pulmonary embolism should facilitate prompt, effective diagnosis

Energy Efficient Routing Protocols for Mobile Ad Hoc Networks

Abstract: Summary Although establishing correct and efficient routes is an important design issue in mobile ad hoc networks (MANETs), a more challenging goal is to provide energy efficient routes because mobile nodes’ operation time is the most critical limiting factor. This article surveys and classifies the energy-aware routing protocols proposed for MANETs. They minimize either the active communication energy required to transmit or receive packets or the inactive energy consumed when a mobile node stays idle but listens to the wireless medium for any possible communication requests from other nodes. Transmission power control approach and load distribution approach belong to the former category, and sleep/power-down mode approach belongs to the latter category. While it is not clear whether any particular algorithm or a class of algorithms is the best for all scenarios, each protocol has definite advantages/disadvantages and is well suited for certain situations. The purpose of this paper is to facilitate the research efforts in combining the existing solutions to offer a more energy efficient routing mechanism. Copyright # 2003 John Wiley & Sons, Ltd.

Downregulation of FUSE-binding protein and c-myc by tRNA synthetase cofactor p38 is required for lung cell differentiation

Abstract: p38 is associated with a macromolecular tRNA synthetase complex1. It has an essential role as a scaffold for the complex, and genetic disruption of p38 in mice causes neonatal lethality2. Here we investigated the molecular mechanisms underlying lethality of p38-mutant mice. p38-deficient mice showed defects in lung differentiation and respiratory distress syndrome. p38 was found to interact with FUSE-binding protein (FBP), a transcriptional activator of c-myc3. Binding of p38 stimulated ubiquitination and degradation of FBP, leading to downregulation of c-myc, which is required for differentiation of functional alveolar type II cells. Transforming growth factor-β (TGF-β) induced p38 expression and promoted its translocation to nuclei for the regulation of FBP and c-myc. Thus, this work identified a new activity of p38 as a mediator of TGF-β signaling and its functional importance in the control of c-myc during lung differentiation.

Menin, a tumor suppressor, represses JunD-mediated transcriptional activity by association with an mSin3A-histone deacetylase complex.

Abstract: Menin, a gene product of multiple endocrine neoplasia type I (MEN1), is known to act as a tumor suppressor to repress JunD transcription factor. However, the mechanism by which Menin represses JunD transcriptional activity was still unclear. In this study, we found that Menin is a corepressor against JunD transcriptional activity via recruitment of histone deacetylases in an mSin3A-dependent manner. The amino acid search revealed that central domain of Menin includes a alpha-helical mSin3-interacting domain [SID (371-387)]. The SID mutation of Menin (L381P/A385P) abolished the interaction between mSin3A and paired amphipathic helix 2 domain of Menin and reduced its ability to repress JunD transcriptional activity, implicating that SID of Menin is important for recruiting an mSin3A-histone deacetylase complex to repress JunD transcriptional activity.

Microbulbifer salipaludis sp. nov., a moderate halophile isolated from a Korean salt marsh.

Abstract: A Gram-negative, non-motile, non-spore-forming, moderately halophilic rod (strain SM-1T) was isolated from salt marsh around the junction of the Youngsan River and the Yellow Sea in Korea and subjected to a polyphasic taxonomic study. This organism grew optimally at 37 degrees C and was able to grow at 10 and 45 degrees C. It grew optimally in the presence of 2-3% (w/v) NaCl. The major fatty acids in strain SM-1T were iso-C15:0 and C16:0. Strain SM-1T and Microbulbifer hydrolyticus DSM 11525T were characterized by having ubiquinone-8 as the predominant respiratory lipoquinone. The DNA G+C content of strain SM-1T was 59 mol%. Phylogenetic analysis based on 16S rDNA sequences showed that strain SM-1T formed a coherent cluster with M. hydrolyticus; this relationship was supported by a bootstrap resampling value of 100%. The level of 16S rDNA identity between strain SM-1T and the type strain of M. hydrolyticus was 98.6%. The mean level of DNA-DNA relatedness between strain SM-1T and the type strain of M. hydrolyticus was 20.6%. Therefore, on the basis of phenotypic properties, phylogeny and genomic data, strain SM-1T should be placed in the genus Microbulbifer as a member of a novel species, for which the name Microbulbifer salipaludis sp. nov. is proposed. The type strain of the novel species is strain SM-1T (=KCCM 41586T =JCM 11542T).

Prevalence of intestinal parasite infections on a national scale among primary schoolchildren in Laos

Abstract: In order to investigate the epidemiological situation of intestinal parasite infections in Laos, parasitological surveys were carried out on a national scale including 17 provinces and the Vientiane Municipality. A total of 29,846 stool specimens were collected from primary schoolchildren from May 2000 to June 2002 and examined once with the cellophane thick smear technique. The cumulative egg positive rate for intestinal helminths was 61.9%. By species, the rate for Ascaris lumbricoides was 34.9%, hookworm 19.1%, Trichuris trichiura 25.8%, Opisthorchis viverrini 10.9%, Taenia spp. 0.6% and Hymenolepis spp. 0.2%. The northern mountainous regions such as Phongsaly, Huaphan or Saysomboune Province showed a higher prevalence (over 70%) of soil- transmitted helminths. The regions along the Mekong River such as Khammuane, Saravane or Savannakhet Province showed a higher prevalence (over 20%) of fish-borne parasites. On the other hand, Schistosoma mansoni eggs were detected in 1.7% of schoolchildren only in Champassak Province, a previously endemic area. The highest prevalence was noted in Phongsaly Province (96.0%) and the lowest in Bolikhamxay Province (27.5%). An additional small-scale survey by cellophane anal swab detected Enterobius vermicularis eggs in 35.7% of 451 schoolchildren aged 6-8 years in Khammuane, Vientiane, Champassak Province and the Vientiane Municipality. Meanwhile, the mean blood haemoglobin level of hookworm-infected children was not lower than that of children not infected with hookworm, suggesting that nutritional factors are more important than parasite infection per se. Nevertheless, the above results indicate that a nationwide parasite control project is necessary to reduce possible morbidity due to parasitic diseases in the country.

Telomeres and telomerase in aging, regeneration and cancer.

Abstract: The finding that telomere shortening limits the replicative lifespan of primary human cells has fueled speculations that telomere shortening plays a role during aging and regeneration of tissues in vivo. Support for this hypothesis comes from studies showing telomere shortening in a variety of human tissues as a consequence of aging and chronic disease. Studies in telomerase-deficient mice have given first experimental support that telomere shortening limits the replicative potential of organs and tissues in vivo and have identified telomerase as a promising target to treat regenerative disorders induced by telomere shortening. A potential downside of such an approach could be the development of malignant tumors, which has been linked to reactivation of telomerase in human cancers. In telomerase-deficient mice, telomere shortening showed a dual role in tumorigenesis, enhancing the initiation of tumors by induction of chromosomal instability but inhibiting tumor progression by induction of DNA-damage responses. The success in using telomerase activation for the treatment of regenerative disorders could depend on which of the mechanisms of telomere shortening is dominantly effecting carcinogenesis.

Bacillus marisflavi sp. nov. and Bacillus aquimaris sp. nov., isolated from sea water of a tidal flat of the Yellow Sea in Korea.

Abstract: Two Gram-positive or Gram-variable, endospore-forming, moderately halophilic rods (strains TF-11(T) and TF-12(T)) were isolated from a tidal flat of the Yellow Sea in Korea and were subjected to a polyphasic taxonomic study. Strains TF-11(T) and TF-12(T) had cell-wall peptidoglycan based on meso-diaminopimelic acid. The predominant menaquinone found in the two strains was MK-7. The cellular fatty acid profiles of both strains contained large amounts of branched and saturated fatty acids. The major fatty acids were anteiso-C(15 : 0) and iso-C(15 : 0). The DNA G+C contents of strains TF-11(T) and TF-12(T) were respectively 49 and 38 mol%. Phylogenetic analysis based on 16S rDNA sequences showed that strains TF-11(T) and TF-12(T) fell within the radiation of the cluster comprising Bacillus species. The level of 16S rDNA sequence similarity between strains TF-11(T) and TF-12(T) was 98.3 %. Strains TF-11(T) and TF-12(T) exhibited levels of 16S rDNA sequence similarity of less than 96.0 and 96.3 %, respectively, to Bacillus species. The mean level of DNA-DNA relatedness between the two strains was approximately 7 %. On the basis of phenotypic and phylogenetic data and genomic distinctiveness, strains TF-11(T) and TF-12(T) should be placed in the genus Bacillus as two distinct novel species, for which the names Bacillus marisflavi sp. nov. (type strain TF-11(T)=KCCM 41588(T)=JCM 11544(T)) and Bacillus aquimaris sp. nov. (type strain TF-12(T)=KCCM 41589(T)=JCM 11545(T)) are proposed.