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The SE continental shelf of the Korean Peninsula was deformed by back-arc rifting associated with the separation of the SW Japan Arc in the Cenozoic. However, the deformation character of the inner continental shelf of the peninsula is not well known. High-resolution seismic profiles reveal a structure representative of a strike-slip duplex on the inner shelf that consists of bounding master faults joined by an array of splay faults. Structural interpretation of this duplex enables us to explain the deformation of the inner shelf with three tectonic stages: (1) generation of normal rift faults in the early stage of back-arc rifting in the late oligocene, (2) sinistral slip on the rift faults under northward compression induced by back-arc closing since the Middle Miocene, and (3) dextral slip on the rift faults induced by ENE–WSW compression since the early pliocene. In the first stage, back-arc rifting generated NNE–SSW oriented rift faults. In the second stage, the interior region between a pair of outer rift faults was subjected to NE–SW extension, creating a duplex with the generation of second-order splay faults oriented NW–SE. In the third stage, the interior region was deformed by ENE–WSW compression, causing convex upward stratigraphic reflectors in individual fault blocks. Our study suggests that the geologic deformation of the continental shelf of the SE Korean Peninsula, up to the inner part, is tied closely to the tectonic evolution in the back-arc region in the Pacific subduction zone. [ABSTRACT FROM AUTHOR]

This study investigated the impact of bronchiectasis on patients admitted to the intensive care unit (ICU) at a hospital in Korea. Patients with bronchiectasis were diagnosed using results of chest computed tomography performed before ICU admission. The severity of bronchiectasis was based on the number of affected lobes, and patients with ≥ 3 bronchiectatic lobes were classified into the severe bronchiectasis group. Overall, 823 patients were enrolled. The mean age was 66.0 ± 13.9 years, and 63.4% were men. Bronchiectasis and severe bronchiectasis were present in 148 (18.0%) and 108 (13.1%) patients, respectively. The increase in the number of bronchiectatic lobes was related to the rise in ICU mortality (P for trend = 0.012) and in-hospital mortality (P for trend = 0.004). Patients with severe bronchiectasis had higher odds for 28-day mortality [odds ratio (OR) 1.122, 95% confidence interval (CI) 1.024–1.230], ICU mortality (OR 1.119, 95% CI 1.023–1.223), and in-hospital mortality (OR 1.208, 95% CI 1.092–1.337). The severe bronchiectasis group showed lower overall survival (log-rank P < 0.001), and the adjusted hazard ratio was 1.535 (95% CI 1.178–2.001). Severe bronchiectasis had a negative impact on all-cause mortality during ICU and hospital stays, resulting in a lower survival rate. [ABSTRACT FROM AUTHOR]

Through a detailed analysis of seismic profile and vibra-/drilling-core sediments (up to 25.5 m long) with AMS 14 C ages from a tidal flat in the mid-western coast of Korea, we reconstruct development of coastal sedimentary sequences in response to sea-level changes for more than about 150 ka, and reveal effect of irregular, complex underlying topography in the Holocene coastal sedimentation. Unit I overlying rock basement and the lower part of Unit II consist of fluvial sediments deposited during sea-level lowstands prior to interglacial period of Eemian Stage (MIS 5e). During the sea-level highstand of MIS 5e, muddy tidal sediments between 7.40 and 10.76 m deep below the present tidal-flat surface were deposited in the upper to middle part of Unit II. The study area had been subaerially exposed for a long duration from MIS 5e to ca. 10 ka. During this period, the muddy tidal sediments in Unit II had been underwent oxidization and significant erosion by fluvial process, forming irregular and complex morphology of the upper boundary of Unit II with a large topographic relief (up to ca. 7 m) even over a short (ca. 560 m) distance. On the upper boundary of Unit II, topographic highs could act as barriers for weakening wave effects from ca. 8–9 ka to 3–4 ka (period of relatively rapid sea-level rise), depositing muddy tidal sediments (Unit III-B). As the muddy tidal sediments (Unit III-B) filled the irregular, complex underlying morphology, surface topography was nearly flat without barriers around about 3–4 ka. Since then, the nearly flat surface morphology without barriers, together with relatively slow sea-level rise and direct exposure of strong onshore winter waves/storms, could promote to deposit wave-/storm-driven sandy sediments (Unit III-A). This study suggests that change in surface morphology could affect stratigraphic evolution of the Holocene coastal sequence by variation in depositional regime. [ABSTRACT FROM AUTHOR]

Objectives. To further understand the expression regulation of MMP-1 and MMP-13 under physiological and pathological conditions, we investigated the combined effects of hypoxia and pro-inflammatory stimuli on the expression of MMP-1 and MMP-13 in rheumatoid synovial fibroblasts.Methods. Synovial fibroblasts were cultured under either hypoxic or normoxic conditions in the presence of IL-1β stimulation. The culture supernatant was analysed for secreted levels of VEGF, MMP-1 and MMP-13. Their gene expression was quantified with real-time and semi-quantitative PCR. Another group of cells was transfected with small-interfering RNA (siRNA) specific for hypoxia-inducible factor-1 α (HIF-1α). The protein levels of HIF-1α were detected by western blot analysis.Results. In response to 10 ng/ml of IL-1β under normoxia, the levels of MMP-1 and MMP-13 increased compared with the levels observed under hypoxia. IL-1β stimulation under hypoxia induced a 2-fold increase in the level of MMP-1 and a 2-fold decrease in the level of MMP-13 compared with cells cultured under normoxia. A similar pattern of differential expression for MMP-1 and MMP-13 was observed with 1 and 5 ng/ml IL-1β, but not at 0.1 ng/ml. The differential expression of MMPs under the combined effect of IL-1β and hypoxia was significantly attenuated by silencing HIF-1α with siRNA.Conclusions. Hypoxia in arthritic joints may differentially affect the IL-1β-stimulated expression of MMP-1 and MMP-13 in rheumatoid synovial fibroblasts. This effect is dependent on HIF-1α expression. This hypoxia-mediated differential effect should be taken into consideration when testing the efficiency of therapies that target HIF-1α. [ABSTRACT FROM PUBLISHER]

Litter decomposition involves multiple complex processes, including interactions between the physicochemical characteristics of litter species and various environmental factors. We selected four representative pine species in South Korea (Pinus densiflora Siebold & Zucc., Pinus thunbergii Parl., Pinus koraiensis Siebold & Zucc., and Pinus rigida Miller) to investigate the decay rate and effects of the physicochemical properties on decomposition. Needle litters were incubated in microcosms at 23 °C for 280 days and retrieved four times in about 70-day intervals. The mass loss showed significant differences among the species and was higher in the order of P. densiflora (30.5%), P. koraiensis (27.8%), P. rigida (26.5%), and P. thunbergii (23.6%). The needle litter decomposition showed a negative relationship with the initial surface area, volume, density, cellulose content, and lignin/nitrogen of the litter, and a positive relationship with the initial specific leaf area (SLA), surface-area-to-volume ratio (SA/V), and water- and ethanol-soluble substances. The decomposition rate was highly affected by the physical properties of litter when compared with the initial chemical litter quality, and it was strongly influenced by SLA and SA/V. Accordingly, the physical properties of pine needle litter, especially SLA and SA/V, may be the key factors, and they could be used as predictive indices for the decomposition rate of pine tree litters. [ABSTRACT FROM AUTHOR]

The NNE-trending dextral Yangsan fault is a > 190-km-long structure in the Korean Peninsula traced to the southeastern coast. The scarcity of Quaternary deposits onland precludes any detailed investigation of the Quaternary activity and structure of the Yangsan fault using seismic reflection profiling. We acquired offshore high-resolution seismic profiles to investigate the extension of the Yangsan fault and constrain its Quaternary activity using stratigraphic markers. The seismic profiles reveal a NNE-trending fault system consisting of a main fault and an array of subsidiary faults that displaced Quaternary sequences. Stratigraphic analysis of seismic profiles indicates that the offshore faults were activated repeatedly in the Quaternary. The up-to-the-east sense of throw on the main fault and plan-view pattern of the fault system are explained by dextral strike-slip faulting. The main fault, when projected toward the Korean Peninsula along its strike, aligns well with the Yangsan fault. We suggest that the offshore fault system is a continuation of the Yangsan fault and has spatial correlation with weak but ongoing seismicity. [ABSTRACT FROM AUTHOR]

• We image how the crustal stucture nature vary in the SE Yellow Sea. • The Gunsan Basin is underlain by relatively thin upper and much thick lower crustal layers. • A transition in crustal structure is recognized from the South China Block to the Korean Peninsula. • The crustal structure is inherited from the growth of Rodinia. Two major tectonic units in NE Asia are the Sino-Korean (or North China) and South China Blocks that collided in the Permo-Triassic periods. The South China Block is suggested to extend eastward to the Korean Peninsula across the southern Yellow Sea. The Gunsan Basin is a well-defined, fault-bounded sedimentary basin in the SE Yellow Sea and is regarded as a structural link of the South China Block to the Korean Peninsula. We collected deep seismic sounding data recorded on ocean bottom seismometers to investigate how the crustal structure and nature of the South China Block vary in the Gunsan Basin toward the middle part of the Korean Peninsula. The main part of the Gunsan Basin is underlain by relatively thin (∼10 km thick) upper and much thicker (∼20 km thick) lower crustal layers, indicating a close affinity to the South China Block; whereas it shows distinction from the Korean Peninsula underlain by upper and lower crustal layers with equal (∼15 km) thickness. A change in crustal structure is recognized under the eastern margin of the Gunsan Basin toward the Korean Peninsula, that features a transition to the Korean Peninsula. The thick lower crustal layer in the Gunsan Basin appears to be inherited from the evolution of the South China Block including crustal shortening associated with the assembly of Rodinia in the Neoproterozoic before the collision between the Sino-Korean and South China Blocks. [ABSTRACT FROM AUTHOR]

The distribution pattern of the phylum Acidobacteria, a previously uncultured bacterial group, was investigated by molecular ecological analyses of global soil samples collected from pristine ecosystems across five continents. Acidobacterial 16S rDNAs were observed in almost all soil samples, and members of acidobacterial primer group A were detected in all samples that harbored the phylum Acidobacteria. Other primer groups, Y, G, and O, showed limited distribution patterns. We further divided the primer groups into acidobacterial subdivisions (class-level). Subdivisional distribution patterns were determined by comparing the observed T-RFs with theoretical T-RFs predicted by in silico digestion of acidobacterial 16S rDNAs. Consistent with the PCR results obtained with subgroup-specific primers, T-RFLP analyses showed that acidobacterial subdivision 1 belonging to primer group A was present in the majority of the soil samples. This study revealed that the phylum Acidobacteria could be globally distributed. At the subdivisional level, acidobacterial subdivision 1 might be the most widely distributed group in this phylum, indicating that members of subdivision 1 might be adapted to various soil environments, and members belonging to other subdivisions might be restricted to certain geographic regions or habitats.

This study was performed to investigate the frequency of human leukocyte antigen (HLA)-B27 subtypes in the Korean population with spondyloarthropathy (SpA). We determined the HLA subtypes of 267 SpA patients who were positive for the B27 antigen (as determined by serology) by using a PEL-FREEZ kit (Dynal Biotech, Wisconsin, USA). Clinical features, including sex, peripheral joint involvement, and the presence of uveitis, were analyzed in a retrospective cohort study. Among 267 patients, 244 were B*2705-positive and 22 were B*2704-positive. One patient was positive for B*2704/2705. No other subtype was observed among the analyzed patients. We found that HLA-B*2705 was the predominant subtype in Koreans with SpA; this finding is remarkable because other Asians such as the Han or the Japanese exclusively have the B*2704 subtype. This result suggests that the clinical features and prevalence of SpA in Koreans may be similar to those observed in Europeans.

The aim of this study was to evaluate the relationship between age and dental maturity and to establish the standard database of dental maturity based on the Demirjian's stages, which can be used for the age estimation of Korean children. For this purpose, dental maturity was measured by the Demirjian's stages on a randomly selected sample of panoramic radiographs taken from 2706 patients between 1 and 20 years of age and analyzed by multiple linear regression analysis based on the method of least squares. The results showed that, except for the third molars, the development of permanent teeth in Korean children was more advanced in females. The Demirjian's stage G of the second molar appeared last in both male and female subjects by age 18, showing 95th percentile at age in the male and female subjects between 16.7-17.4 years and 17.1-17.3 years, respectively. Coefficients of determination (r(2)) of the Demirjian's stages relative to age in regression analysis were 0.9721 in male and 0.9740 in female subjects. The standard error was 0.63 years in male and 0.62 years in female subjects. The estimated age according to regression analysis was within +/-1.0 year of the actual age in 92.0% of male and 92.5% of female subjects. Collectively, the data of the present study can be used as a reference for dental maturity and a standard for age estimation of Korean children.

The impact of treatment delays to reperfusion on patient mortality after primary percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI) is controversial. We analyzed 5,069 patients included in the Korea Acute Myocardial Infarction Registry (KAMIR) between November 2005 and January 2007. We selected 1,416 patients who presented within 12 hr of symptom onset and who were treated with primary PCI. The overall mortality at one month was 4.4%. The medians of door-to-balloon time, symptom onset-to-balloon time, and symptom onset-to-door time were 90 (interquartile range, 65-136), 274 (185-442), and 163 min (90-285), respectively. One-month mortality was not increased significantly with any increasing delay in door-to-balloon time (4.3% for < or =90 min, 4.4% for >90 min; p=0.94), symptom onset-to-balloon time (3.9% for < or =240 min, 4.8% for >240 min; p=0.41), and symptom onset-to-door time (3.3% for < or =120 min, 5.0% for >120 min; p=0.13). These time variables had no impact on one-month mortality in any subgroup. Thus, this first nationwide registry data in Korea showed a good result of primary PCI, and the patient prognosis may not depend on the initial treatment delay using the current protocols.

Specific antagonists of tumor necrosis factor (TNFalpha) have rapidly gain popularity for the treatment of ankylosing spondylitis (AS). The dose of etanercept has not been determined in Asia, especially in Korea. This study was designed to investigate the maintaining effect of low-dose (25 mg/week) etanercept in Korean patients with AS and after discontinuation, the duration to be aggravated. Patients who had active AS [Bath AS Disease Activity Index (BASDAI) > or =4] were treated with 50 mg of etanercept per week for 3 months. After that, for 6 months, the patients were treated with 25 mg of etanercept per week. We evaluated the serum erythrocyte sediment rate (ESR), C-reactive protein (CRP), and BASDAI every 1 month for 3 months and every 2-3 months during the remaining 6 months. After all schedules of treatment were finished, we reevaluated ESR, CRP, and BASDAI every 4 months until recurrence. Twenty-seven AS patients received etanercept. Twenty-three patients completed treatment for 3 months with a dose of 50 mg/week. Among them, 18 completed for 6 months with a dose of 25 mg/week and discontinued. Mean age was 30.0 +/- 5.4 years and mean disease duration was 7.5 +/- 6.5 years. These 18 patients were evaluated for BASDAI, ESR, and CRP every 4 weeks. After discontinuation, mean duration to recur was 9.2 +/- 6.1 weeks. Twenty-five milligrams of etanercept per week is effective enough to maintain remission in AS. After discontinuation, this effect was maintained by using a dose of 50 mg of etanercept per week.

A proteomic approach has been adopted to investigate the low-abundant proteins in rice leaf in response to cold stress. Rice seedlings were exposed to different temperatures, such as 5 or 10 degrees C, and samples were collected after different time course. To eliminate the high-abundant proteins in leaf tissues such as ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), proteins were fractionated by polyethylene glycol (PEG). The elimination of Rubisco from the protein samples was confirmed by Western blot analysis. The PEG fractionated protein samples were separated by 2-DE and visualized by silver or CBB staining. A total 12 up-regulated protein spots were identified using the analysis of MALDI-TOF mass spectrometry or ESI MS/MS. We identified some novel proteins such as cysteine proteinase, thioredoxin peroxidase, a RING zinc finger protein-like, drought-inducible late embryogenesis abundant, and a fibrillin-like protein that had not yet been reported in the earlier reports on cold proteomic analysis. The identification of some novel low-abundant proteins in response to cold stress may provide a new homeostasis to develop enhanced cold tolerance transgenic plants. Thus, we propose that a PEG fractionation system can be used as an influential protein extraction method from the leaf samples, which can lead to knowledge of the expression pattern of low-abundant proteins in response to various biotic or abiotic stresses.

Objectives: We evaluated the efficacy and safety of long-acting risperidone for 48-week period in Korean patients., Methods: This was a non-randomized, open-label, single-centered, 48-week study. Each of the participants visited the hospital every 2 weeks, and injections were given at each visit. Complete evaluations were done on five occasions (baseline, 12, 24, 36, 48 weeks). We used Clinical Global Impression, Positive and Negative Syndrome Scale, Global Assessment of Functioning, Subjective Well-being under Neuroleptic treatment scale and Short-form-36 health survey. Drug attitude inventory and Drug Induced Extra-Pyramidal Symptoms Scale were also used., Results: Forty patients were enrolled, and twenty-five patients completed this study. The therapeutic response rate was 36.1% in LOCF and 48% in completer's analysis. Scores on CGI, PANSS subscales and total were significantly decreased over 48-week period. Scores on other assessments did not show any significant changes over the period. At weeks 48, there was no significant difference in the changes of scores from baseline on self-rated assessments between the clinical improvement and non-improvement groups., Conclusions: Our study showed significant improvement of investigator-rated psychiatric symptoms in long-term follow-up using long-acting risperidone. Further researches would be required to find out the effects of the psychiatric symptom improvements on overall changes in perceived functioning and well-being.

The PD-1 (programmed death 1) molecule is a negative regulator of T cells. PDCD1 (programmed cell death 1) has been reported to have a genetic association in systemic lupus erythematosus and rheumatoid arthritis in Caucasians. However, there are no reports on the association between this gene and ankylosing spondylitis (AS). The present study investigated the association of the PD-1 polymorphisms and the haplotypes with AS in a Korean population sample. In a case-control association study, two single-nucleotide polymorphisms, PD-1.5 C/T and PD-1.9 T/C, were genotyped in 95 AS patients and 130 healthy controls. The T allele of the PD-1.9 polymorphism was more frequent in the Korean male population with AS than in the Korean male controls (21.0% versus 6.9%, odds ratio 1.89, 95% confidence interval 1.483 to 2.408). The frequency of the CT haplotype (PD-1.5 C/T and PD-1.9 T/C) was higher in the AS patients (19%) than the controls (5.4%) (odds ratio 1.83, 95% confidence interval 1.559 to 2.521). The PD-1 polymorphism was demonstrated in Korean AS patients. The results suggest a genetic association between the PD-1 polymorphism and susceptibility to AS.

The purpose of this study was to investigate the operative results and the clinical outcomes for octogenarians who underwent cardiac surgery. Twenty consecutive octogenarians who had cardiac operations at Samsung Medical Center from October 1994 through December 2004 were included in the study. The medical records were retrospectively reviewed and the follow-up results were obtained by the interview. The patients were 15 men and 5 women, and their mean age was 83.1 yr (range: 80-89 yr). The surgical priority was urgent for 5 patients and it was elective for 15 patients. Coronary artery bypass grafting (CABG) was performed in 14 patients, valve surgery was performed in 4 patients and CABG plus valve surgery was performed in 2 patients. There was one hospital death on day one after urgent CABG in an 80-yr-old man who had left main coronary artery occlusion. There were three deaths during the follow-up. Sudden death occurred in one patient at 2 months after valve surgery, and there were two non-cardiac deaths at 12 and 14 months, respectively, after CABG. Non-fatal postoperative complications occurred in 2 of 5 urgent patients and in 3 of 15 electives. The survival rate for the 19 hospital survivors at 24 months after surgery was 80% and the mean follow-up period was 22.5 months (range: 1-58 months). In conclusion, cardiac surgery could be performed within acceptable limits of the risk and its long-term results could be expected to be favorable for the octogenarians.