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Search Results: 1 - 10 of 15086 matches for " Ki Young Na "
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Acute Cerebellar Infarction After Percutaneous Vertebroplasty
Ki Seong EOM,Kim Ji NA,Kim Tae YOUNG
Journal of Neurological Sciences , 2012,
Abstract: Percutaneous vertebroplasty (PV) is considered a very safe and effective procedure to treat painful compression fractures, and this procedure rarely results in complications. To our knowledge, there is only one case report of the complications associated with cerebral infarction after PV. Here, we report a rare case of postoperative acute cerebellar infarction that was caused by vertebral artery occlusion. We present a rare case of left acute cerebellar infarction that developed approximately 6 h after PV in an 82-year-old woman. Brain magnetic resonance (MR) angiography showed complete occlusion of the left vertebral artery. The patient was treated conservatively. To the best of our knowledge, acute cerebellar infarction after PV has yet not been reported. Although we cannot rule out the possibility of embolism because the patient was in the prone position with her head rotated during the operation, there are no specific links between acute arterial infarction and PV. Thus, this complication may be incidental rather than causal. Nevertheless, special attention should be paid to the postoperative variable changes in aged patients.
Glomerular Filtration Rate and Proteinuria: Association with Mortality and Renal Progression in a Prospective Cohort of a Community-Based Elderly Population
Se Won Oh, Sejoong Kim, Ki Young Na, Ki Woong Kim, Dong-Wan Chae, Ho Jun Chin
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0094120
Abstract: Limited prospective data are available on the importance of estimated glomerular filtration rate (GFR) and proteinuria in the prediction of all-cause mortality (ACM) in community-based elderly populations. We examined the relationship between GFR or proteinuria and ACM in 949 randomly selected community-dwelling elderly subjects (aged ≥65 years) over a 5-year period. A spot urine sample was used to measure proteinuria by the dipstick test, and GFR was estimated using the chronic kidney disease-epidemiology collaboration (CKD-EPI) equation. Information about mortality and causes of death was collected by direct enquiry with the subjects and from the national mortality data. Compared to subjects without proteinuria, those with proteinuria of grade ≥1+ had a 1.725-fold (1.134–2.625) higher risk of ACM. Compared to subjects with GFR ≥90 ml/min/1.73 m2, those with GFR<45 ml/min/1.73 m2 had a 2.357 -fold (1.170–4.750) higher risk for ACM. Among the 403 subjects included in the analysis of renal progression, the annual rate of GFR change during follow-up period was ?0.52±2.35 ml/min/1.73 m2/year. The renal progression rate was 7.315-fold (1.841–29.071) higher in subjects with GFR<60 ml/min/1.73 m2 than in those with GFR ≥60 ml/min/1.73 m2. Among a community-dwelling elderly Korean population, decreased GFR of <45 ml/min/1.73 m2 and proteinuria were independent risk factors for ACM.
Mechanisms by Which Licochalcone E Exhibits Potent Anti-Inflammatory Properties: Studies with Phorbol Ester-Treated Mouse Skin and Lipopolysaccharide-Stimulated Murine Macrophages
Han Na Lee,Han Jin Cho,Do Young Lim,Young-Hee Kang,Ki Won Lee,Jung Han Yoon Park
International Journal of Molecular Sciences , 2013, DOI: 10.3390/ijms140610926
Abstract: In this study we found that licochalcone E (LicE), a recently isolated retrochalcone from Glycyrrhiza inflata, exhibits potent anti-inflammatory effects in 12- O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema and lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophage models. Topical application of LicE (0.5–2 mg) effectively inhibited TPA-induced (1) ear edema formation; (2) phosphorylation of stress-activated protein kinase/c-Jun- N-terminal kinase (SAPK/JNK), c-Jun, and extracellular signal regulated kinase 1/2; and (3) expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 proteins in mouse skin. The treatment of RAW 264.7 cells with LicE (2.5–7.5 μmol/L) induced a profound reduction in LPS-induced (1) release of NO and prostaglandin E 2; (2) mRNA expression and secretion of interleukin (IL)-6, IL-1β and tumor necrosis factor-α; (3) promoter activity of iNOS and COX-2 and expression of their corresponding mRNAs and proteins; (4) activation of AKT, p38 mitogen activated protein kinase (MAPK), SAPK/JNK and c-Jun; (5) phosphorylation of inhibitor of κB (IκB) kinase-αβ and IκBα, degradation of IκBα, translocation of p65 (RelA) to the nucleus and transcriptional activity of nuclear factor (NF)-κB; and (6) transcriptional activity of activator protein (AP)-1. These results indicate that the LicE inhibition of NF-κB and AP-1 transcriptional activity through the inhibition of AKT and MAPK activation contributes to decreases in the expression of pro-inflammatory cytokines and the inducible enzymes iNOS and COX-2.
Relationship between Changes in Body Fat and a Decline of Renal Function in the Elderly
Se Won Oh, Shin Young Ahn, Xu Jianwei, Ki Woong Kim, Sejoong Kim, Ki Young Na, Dong Wan Chae, Suhnggwon Kim, Ho Jun Chin
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0084052
Abstract: Obesity is a risk factor for chronic kidney disease, and its prevalence among the elderly is increasing. We investigated the effects of changes in body fat percentage (BFP) on the longitudinal changes in the estimated glomerular filtration rate (eGFR) in the elderly. This prospective cohort study included 390 participants aged >65 years who underwent bioelectrical impedance analysis at baseline and follow-up as a part of the Korean Longitudinal Study on Health and Aging. After a median follow-up period of 5.3 years, BFP was significantly higher than that at the start point (P<0.05). Participants who had the largest increase in BFP had the highest BMI and waist circumference (WC) (P<0.001). The highest tertile had the highest white blood cell count and erythrocyte sedimentation rate, incidence of rapid progression, and decline in eGFR >25% (P≤0.017, P = 0.025, P = 0.005, respectively). The lowest tertile had the lowest triglyceride and highest high-density lipoprotein levels (P<0.05). The adjusted decline rate in eGFR was correlated with a change in BFP (P = 0.039), but not with that in BMI or WC. The highest tertile had a 4.875-fold increase in the risk for rapid progression to a decline in eGFR (95% CI: 1.366–17.397) and a 4.931-fold decrease in the risk to a decline in eGFR>25% (95% CI: 1.617–15.037), when compared with the lowest tertile. In subgroup analysis, the incidence of renal outcomes was significantly increased according to the increase in BFP in patients with lower eGFR (P≤0.010). A change in BFP may be associated with inflammation and dyslipidemia development, and longitudinal changes in body fat are related to a decrease in eGFR in the elderly.
Incident Chronic Kidney Disease and Newly Developed Complications Related to Renal Dysfunction in an Elderly Population during 5 Years: A Community-Based Elderly Population Cohort Study
Shin Young Ahn, Jiwon Ryu, Seon Ha Baek, Sejoong Kim, Ki Young Na, Ki Woong Kim, Dong-Wan Chae, Ho Jun Chin
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0084467
Abstract: Background Few studies have evaluated the association between incident chronic kidney disease (CKD) and related complications, especially in elderly population. We attempted to verify the association between GFR and concurrent CKD complications and elucidate the temporal relationship between incident CKD and new CKD complications in a community-based prospective elderly cohort. Method We analyzed the available data from 984 participants in the Korean Longitudinal Study on Health and Aging. Participants were categorized into 6 groups according to eGFR at baseline examination (≥90, 75–89, 60–74, 45–59, 30–44, and <30 ml/min/1.73 m2). Result The mean age of study population was 76 ± 9.1 years and mean eGFR was 72.3 ± 17.0 ml/min/1.73 m2. Compared to eGFR group 1, the odds ratio (OR) for hypertension was 2.363 (95% CI, 1.299-4.298) in group 4, 5.191 (2.074-12.995) in group 5, and 13.675 (1.611-115.806) in group 6; for anemia, 7.842 (2.265-27.153) in group 5 and 13.019 (2.920-58.047) in group 6; for acidosis, 69.580 (6.770-715.147) in group 6; and for hyperkalemia, 19.177 (1.798-204.474) in group 6. Over a 5-year observational period, CKD developed in 34 (9.6%) among 354 participants with GFR ≥ 60 ml/min/1.73 m2 at basal examination. The estimated mean number of new complications according to analysis of co-variance was 0.52 (95% CI, 0.35–0.68) in subjects with incident CKD and 0.24 (0.19–0.29) in subjects without CKD (p = 0.002). Subjects with incident CKD had a 2.792-fold higher risk of developing new CKD complications. A GFR level of 52.4 ml/min/1.73 m2 (p = 0.032) predicted the development of a new CKD complication with a 90% sensitivity. Conclusion In an elderly prospective cohort, CKD diagnosed by current criteria is related to an increase in the number of concurrent CKD complications and the development of new CKD complications.
Hypoxia-Inducible Factor Activation Protects the Kidney from Gentamicin-Induced Acute Injury
Jeong-myung Ahn, Sun Jin You, Yun-Mi Lee, Se-Won Oh, Shin-young Ahn, Sejoong Kim, Ho Jun Chin, Dong-Wan Chae, Ki Young Na
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0048952
Abstract: Gentamicin nephrotoxicity is one of the most common causes of acute kidney injury (AKI). Hypoxia-inducible factor (HIF) is effective in protecting the kidney from ischemic and toxic injury. Increased expression of HIF-1α mRNA has been reported in rats with gentamicin-induced renal injury. We hypothesizd that we could study the role of HIF in gentamicin-induced AKI by modulating HIF activity. In this study, we investigated whether HIF activation had protective effects on gentamicin-induced renal tubule cell injury. Gentamicin-induced AKI was established in male Sprague-Dawley rats. Cobalt was continuously infused into the rats to activate HIF. HK-2 cells were pre-treated with cobalt or dimethyloxalylglycine (DMOG) to activate HIF and were then exposed to gentamicin. Cobalt or DMOG significantly increased HIF-1α expression in rat kidneys and HK-2 cells. In HK-2 cells, HIF inhibited gentamicin-induced reactive oxygen species (ROS) formation. HIF also protected these cells from apoptosis by reducing caspase-3 activity and the amount of cleaved caspase-3, and -9 proteins. Increased expression of HIF-1α reduced the number of gentamicin-induced apoptotic cells in rat kidneys and HK-2 cells. HIF activation improved the creatinine clearance and proteinuria in gentamicin-induced AKI. HIF activation also ameliorated the extent of histologic injury and reduced macrophage infiltration into the tubulointerstitium. In gentamicin-induced AKI, the activation of HIF by cobalt or DMOG attenuated renal dysfunction, proteinuria, and structural damage through a reduction of oxidative stress, inflammation, and apoptosis in renal tubular epithelial cells.
The Occurrence of Warfarin-Related Nephropathy and Effects on Renal and Patient Outcomes in Korean Patients
Jung Nam An, Shin Young Ahn, Chang-Hwan Yoon, Tae-Jin Youn, Moon-Ku Han, Sejoong Kim, Ho Jun Chin, Ki Young Na, Dong-Wan Chae
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0057661
Abstract: Background Warfarin-related nephropathy (WRN) is a recently described disease entity, in which excessive warfarinization (international normalized ratio (INR) >3.0) causes acute kidney injury. Previous reports regarding WRN included few Asian patients who might have differed from the western WRN patients in terms of genetic and environmental factors. Methods During the period of March 2003 to December 2011, the data about a total of 1297 patients who had serum creatinine (sCr) level measured within 1 week after INR >3.0 and within 6 months before INR >3.0 was analyzed through the retrospective review of electronic medical records of a single tertiary hospital in Korea. Result WRN developed in 19.3% of patients having excessive warfarinization. The incidence was higher in the chronic kidney disease (CKD) group than the non-CKD group. The risk of WRN increased as the basal serum albumin level decreased and was strongly associated with highest quartile serum AST level at post INR elevation and the presence of congestive heart failure. But the presence of atrial fibrillation was protective against the development of WRN. Neither the presence of CKD nor basal estimated glomerular filtration rate (eGFR) was an independent risk factor for WRN. Despite no difference in the basal sCr level, the sCr level was higher in patients with WRN than those without WRN after follow-up. The mortality rates were also higher in patients with WRN. Conclusions WRN developed in 19.3% of patients having excessive warfarinization. A lower basal serum albumin, highest quartile serum AST level at post INR elevation, and congestive heart failure were associated with the occurrence of WRN. The development of WRN adversely affected renal and patient outcomes.
Increased Corticomuscular Coherence in Idiopathic REM Sleep Behavior Disorder
Ki-Young Jung
Frontiers in Neurology , 2012, DOI: 10.3389/fneur.2012.00060
Abstract: The authors hypothesized that if locomotor drive increases along with rapid eye movement (REM) sleep without atonia in idiopathic REM sleep behavior disorder (RBD), then RBD patients would have greater corticomuscular coherence (CMC) values during REM sleep than at other sleep stages and than in healthy control subjects during REM sleep. To explore this hypothesis, we analyzed beta frequency range CMC between sensorimotor cortex electroencephalography (EEG) and chin/limb muscle EMG in idiopathic RBD patients. Eleven drug naive idiopathic RBD patients and 11 age-matched healthy control subjects were included in the present study. All participants completed subjective sleep questionnaires and underwent polysomnography for one night. The CMC value between EEGs recorded at central electrodes and EMGs acquired at leg and chin muscles were computed and compared by repeated measures analysis of variance (ANOVA). Sleep stages and muscle (i.e., chin vs. leg) served as within-subject factors, and group served as the between-subject factor. Repeated measures ANOVA revealed no significant main effect of group (F1,20 = 0.571, p = 0.458) or muscle (F1,20 = 1.283, p = 0.271). However, sleep stage was found to have a significant main effect (F2.067,41.332 = 20.912, p < 0.001). The interaction between group and sleep stage was significant (F2.067,41.332 = 3.438, p = 0.040). RBD patients had a significantly higher CMC value than controls during REM sleep (0.047 ± 0.00 vs. 0.052 ± 0.00, respectively, p = 0.007). This study reveals increased CMC during REM sleep in patients with RBD, which indicates increased cortical locomotor drive. Furthermore, this study supports the hypothesis that sufficient locomotor drive plays a role in the pathophysiology of RBD in addition to REM sleep without atonia.
Guided Dispersion Characteristics of Subwavelength Nanoscale Plasmonic Coaxial Lines
Ki Young Kim
Physics , 2009,
Abstract: The guided dispersion characteristics of subwavelength nanoscale plasmonic coaxial lines are analyzed in detail over a wide optical frequency range below the plasma frequency with a varying gap between the inner and outer plasmonic conductors, providing important preliminary information for understanding the guided mode characteristics of subwavelength nanoscale coaxial lines with plasmonic metals. In particular, when the inner or outer radius is varied, guided modes with similar and dissimilar dispersive features are obtained and discussed. A brief comparison of the propagating modes for the present subwavelength plasmonic coaxial lines and those for a subwavelength plasmonic hole and wire is also made.
Fundamental guided electromagnetic dispersion characteristics in lossless dispersive metamaterial clad circular air hole waveguides
Ki Young Kim
Physics , 2009, DOI: 10.1088/1464-4258/9/11/016
Abstract: The fundamental guided electromagnetic dispersion characteristics in lossless dispersive metamaterial clad circular air hole waveguides are investigated. Two operating guided modes are found to exist: circular waveguide and surface plasmon polariton modes that support fast and slow waves, respectively. Hybrid mode classifications are also made in an empirical manner so that the guided modes can be sorted into either TM-like or TE-like modes in terms of their unique dispersion characteristics. Unusual dispersion characteristics, including multi-valued propagation constants at a single frequency, backward waves, and subwavelength guided propagations, are observed and discussed in relation to the air-hole radii and dielectric and magnetic constants of the metamaterial clad. A discussion comparing the extraordinary dispersion characteristics with those of other dielectric, plasmonic, and metamaterial waveguides is also included.
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