[show abstract][hide abstract] ABSTRACT: Purpose: Estimation of body fluid volume in hyponatremia is useful for diagnosis and therapeutic decision-making. Physical examination has been generally used to estimate body fluid volume, but it depends on the physician's abilities. Bioimpedance spectroscopy has been suggested to be a reliable method for the estimation of body fluid volume. Therefore, this study investigated whether bioimpedance spectroscopy could replace physical examination in hyponatremia. Materials and Methods: The study included 30 patients with hyponatremia. At the time of the initial visit, body fluid volume was estimated simultaneously by both physical examination and bioimpedance spectroscopy. Estimation of body fluid status by clinical diagnosis was performed as well, which determined body fluid status corresponds with the most likely cause of hyponatremia (clinical body fluid estimation). Results: The results of body fluid volume estimated by physical examination, bioimpedance spectroscopy, and clinical body fluid estimation showed that 9, 10, and 9 patients, respectively, were hypervolemic; 13, 15 and 16 patients, respectively, were euvolemic; and 8, 5, and 5 patients, respectively, were hypovolemic. Cohen's kappa analysis showed a significant agreement between physical examination and bioimpedance spectroscopy (kappa coefficient, 0.632, p<0.001). In addition, bioimpedance spectroscopy showed a higher level of agreement with clinical body fluid estimation than physical examination (kappa coefficient, 0.602 vs. 0.524). Conclusion: This study suggests that bioimpedance spectroscopy could replace physical examination for estimating body fluid status in hyponatremia. In addition, bioimpedance spectroscopy might correspond better with clinical diagnosis than physical examination in the estimation of body fluid status in hyponatremia.
Yonsei medical journal 03/2014; 55(2):482-6. · 0.77 Impact Factor
[show abstract][hide abstract] ABSTRACT: Epitaxial semiconductor/graphene double heterostructures are fabricated by vapor-phase van der Waals epitaxy of InAs on both sides of suspended graphene, as reported on page 6847. K. S. Kim, Y. J. Hong and co-workers demonstrate that the weak van der Waals attraction facilitates a preferential growth direction of InAs exclusively along the As-polar direction, which results in a polarity inversion of the double heterostructures. The first-principles and density functional calculations clarify why and how the conductive graphene layer yields the polarity inversion for sp(3) /sp(2) /sp(3) -type double heterostructures.
[show abstract][hide abstract] ABSTRACT: Autism spectrum disorder (ASD) is a neurodevelopmental syndrome associated with impairments of reciprocal communication and cognitive function. Associations between single-nucleotide polymorphisms (SNPs) and ASD were analysed by logistic regression. Polymorphisms in FNDC3A exhibited significant associations in genotype and diplotype analyses. We conclude that FNDC3A influences the prevalence of ASD.
[show abstract][hide abstract] ABSTRACT: Background: The cyclosporin A (CsA) nephrotoxicity limits its usefulness as an immunosuppression. We studied the administration of both nitroprusside and phosphodiesterase-5 inhibitor (udenafil) in order to determine whether these agents could ameliorate the renal injury in CsA nephrotoxicity. Methods: 30 8-week-old SD rats were divided into 5 groups: the control (1), SQ with 15 mg/kg CsA (Group 2), CsA along with 5 mg/kg IP nitroprusside (Group 3), CsA with 10 mg/kg PO udenafil (Group 4), and CsA with udenafil and nitroprusside (Group 5). Results: Group showed an increase in creatinine compared o the control group. Group 5 showed a decrease in creatinine compared to Group 2. In TUNEL, Group 2 increased apoptosis in proximal tubules compared to control. Group 5 showed a decrease in apoptosis compared to Groups 2, 3, and 4. In IHC, the eNOS in Group 2 was stronger than in the controls. Groups 3, 4, and 5 showed decreased staining intensity compared to Group 2. In IHC, the VEGF in Groups 2, 3, and 4 increased compared to the controls. The eNOS protein expression was increased in both Groups 3 and 5 compared to the controls. The VEGF protein expression was increased in Groups 3 and 5 compared to Group 2. The eNOS mRNA was decreased in Group 2 compared to the control group and tended to increase in Groups 3, 4, and 5 compared to Group 2. The VEGF mRNA was increased in Group 2 and tended to increase more in Groups 3 and 5. Conclusion: The udenafil and nitroprusside ameliorated renal injury in rat model of CsA nephrotoxicity. The mechanism appears to be associated with decreasing tubular apoptosis by decreasing eNOS and increasing VEGF.
[show abstract][hide abstract] ABSTRACT: BACKGROUND:: Genetic variations in interleukin 28B (IL28B) have been strongly associated with a sustained virological response (SVR) in European and African-American patients. Genetic variation of IL28B was investigated in healthy controls and chronic hepatitis C (CHC) patients, and the treatment response in the CHC patients was analyzed according to IL28B polymorphism in the Korean population. METHODS:: IL28B polymorphisms (rs12979860 and rs8099917) were studied in 200 healthy controls and in 167 CHC patients who were treated with peginterferon-α and ribavirin. RESULTS:: The prevalence of rs12979860 in healthy controls is as follows: the CC-genotype was 88.5%, the CT-genotype was 11.5%, and the TT-genotype was not found. The prevalence of rs8099917 in healthy controls is as follows: the TT-genotype was 89.5%, the TG-genotype was 10.5%, and the GG-genotype was not found. The CC-genotype of rs12979860 and the TT-genotype of rs8099917 were found to be closely related (linkage disequilibrium; D'=1.0, χ=0.9082). In 106 CHC patients treated with peginterferon and ribavirin, the SVR was 67.2% (n=58) for 1b, 91.6% (n=47) for 2a. In hepatitis C virus (HCV) genotype 1b with respect to rs12979860, the SVR in CC-genotype was 72.9% and that in CT-genotype was 40.0%. On investigating predictive factors for SVR, pretreatment low-HCV RNA levels, HCV genotype non-1, early virological response, and also the IL28B CC-genotype for rs12979860 were good indicators of an SVR. CONCLUSIONS:: In Korea, genetic variation of IL28B is different from that in western countries in view of high prevalence of rs12979860 CC-genotype. It seems likely that a high SVR in Korean patients with genotype 1 CHC patients is due to the genetic polymorphism in IL28B.
Journal of clinical gastroenterology 02/2013; · 2.21 Impact Factor
[show abstract][hide abstract] ABSTRACT: Here, we report a substrate-induced intercalation phenomenon of an organic solvent at the interface between monolayer graphene and a target substrate. A simple dipping of the transferred chemical vapor deposition (CVD)-grown graphene on the SiO(2) substrate into chloroform (CHCl(3), CF), a common organic solvent, induces a spontaneous formation of CF clusters beneath the basal plane of the graphene as well as inside the wrinkles. The microscopic and spectroscopic observations showed the doping behavior of monolayer graphene, which indicates the adsorption of CF to monolayer graphene. Interestingly, the intercalated organic solvent showed remarkable stability for over 40 days under ambient conditions. To reveal the underlying mechanism of the stable solvent intercalation, desorption energy of CF molecules at the graphene/substrate interface was measured using Arrhenius plots of the conductance change upon time and temperature. Two stages of solvent intercalations with high desorption energies (70 and 370 meV) were observed along with the consecutive shrinkage of the solvent clusters at the basal plane and the wrinkles, respectively. Moreover, the theoretical calculation based on density functional theory (DFT) also shows the strong intercalation energy of CF between monolayer graphene and the SiO(2) substrate, which results from the stabilization of the graphene-SiO(2) interactions. Furthermore, the thermal response of the conductance could be utilized to maintain a certain degree of p-doping of monolayer graphene, which provides the facile, sustainable, and controllable large-area doping method of graphene for future generation of printed flexible electronics.
[show abstract][hide abstract] ABSTRACT: Nurr1 is an orphan nuclear receptor best known for its essential role in the development and maintenance of midbrain dopaminergic (DA) neurons. During DA neurogenesis, Nurr1 directly targets human tyrosine hydroxylase (hTH). Here we investigated this targeting to identify the molecular mechanisms by which Nurr1 regulates DA neurogenesis. We previously cloned the hTH promoter and found three consensus elements for Nurr1 binding: NBRE-A, -B, and -C. In the present study, gel retardation and luciferase assays using hTH constructs showed that Nurr1 preferentially bound to NBRE-A, through which it mediated transcriptional activity. Furthermore, Nurr1 displayed dual-function transcriptional activities depending on the cell type. In DA-like SH-SY5Y cells, Nurr1 dose-dependently stimulated hTH-3174 promoter activity by 7- to 11-fold. However, in the human neural stem cell (hNSC) line HB1.F3, Nurr1 strongly repressed transcription from the same promoter. This repression was relieved by mutation of only the NBRE-A element and by nicotinamide [an inhibitor of class III histone deacetylases (HDACs), such as SIRT1], but not by trichostatin A (an inhibitor of class I and II HDACs). SIRT1 was strongly expressed in the nucleus of HB1.F3 cells, while it was localized in the cytoplasm in SH-SY5Y cells. ChIP assays of HB1.F3 cells showed that Nurr1 overexpression significantly increased the SIRT1 occupancy of the NBRE-A hTH promoter region, while low SIRT1 levels were observed in control cells. In contrast, no significant SIRT1 recruitment was observed in SH-SY5Y cells. These results indicate that differential SIRT1 localization may be involved in hTH gene regulation. Overall, our findings suggest that Nurr1 exists in dual transcriptional complexes, including co-repressor complexes that can be remodeled to become co-activators and can fine-tune hTH gene transcription during human DA neurogenesis.
PLoS ONE 01/2013; 8(8):e71469. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Hepatitis C virus (HCV) infection is a major cause of liver disease, including cirrhosis and hepatocellular carcinoma. Due to significant adverse effects and emergence of resistant strains of currently developed anti-HCV agents, plant extracts have been considered to be potential sources of new bioactive compounds against HCV. The aim of this study was to evaluate the functional effects of triterpenoid saponins contained in the root extract of Platycodon grandiflorum (PG) on viral enzyme activities and replication in both HCV replicon cells and cell culture grown HCV- (HCVcc-) infected cells. Inhibitory activities of triterpenoid saponins from PG were verified by NS5B RNA-dependent RNA polymerase assay and were further confirmed in the context of HCV replication. Six triterpenoid saponins (platycodin D, platycodin D2, platycodin D3, deapioplatycodin D, deapioplatycodin D2, and platyconic acid A), PG saponin mixture (PGSM), were identified as active components exerting anti-HCV activity. Importantly, PGSM exerted synergistic anti-HCV activity in combination with either interferon- α or NS5A inhibitors. We demonstrated that combinatorial treatment of PGSM and IFN- α efficiently suppressed colony formation with significant reduction in drug resistant variant of HCV. These data suggest that triterpenoid saponin may represent a novel anti-HCV therapeutic agent.
Evidence-based Complementary and Alternative Medicine 01/2013; 2013:560417. · 1.72 Impact Factor
[show abstract][hide abstract] ABSTRACT: Diastolic dysfunction occurs frequently in patients with chronic kidney disease (CKD) and is associated with heart failure (HF) or mortality. We investigated whether the ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity (E/e' ratio), estimated using tissue Doppler imaging, has prognostic value for cardiovascular morbidity and all-cause mortality in patients with CKD.
For 186 patients with CKD of stages III to V, we obtained echocardiograms with tissue Doppler imaging. A 5-year follow-up of 136 patients was performed based on hospital records and telephone interviews. The enrolled patients (79 males and 57 females) were categorized into the following CKD subgroups: stage III (n = 25); stage IV (n = 22); and stage V (n = 89).
The average follow-up period was 30.45 months and the mean age of the patients was 61.13 years. The mortality rate after 5 years was 60.0%. The causes of death were: sepsis, 21.9%; HF, 16.2%; and sudden death, 15.2%. Age (p = 0.000), increased C-reactive protein level (p = 0.018), and increased E/e' ratio (p = 0.048) were found to correlate with mortality. Age (p = 0.000), decreased ejection fraction (p = 0.003), and increased E/e' ratio (p = 0.045) correlated with cardiovascular event.
The E/e' ratio can predict mortality and cardiovascular events in patients with CKD who have diastolic dysfunction.
The Korean Journal of Internal Medicine 01/2013; 28(1):35-44.
[show abstract][hide abstract] ABSTRACT: Sustained virologic response (SVR) for the treatment of chronic hepatitis C (CHC) may differ with ethnicity due to differences in genetic traits. This study evaluated the efficacy of peginterferon and ribavirin, and the association between IL28B genotypes and the treatment efficacy in Korean CHC patients.
This was a retrospective cohort study using data from medical records. Eighty-five CHC patients were eligible for assessment of the efficacy of antiviral therapy, and 47 patients were available for an IL28B genetic study, which was performed using the Multiplex tetra-primer PCR method for rs12979860.
Overall, the early virologic response rate was 87.1%: 84.9% in HCV genotype 1 and 90.6% in genotype 2. The overall end-of-treatment virologic response rate was 81.2%: 75.5% in genotype 1 and 90.6% in genotype 2. The overall SVR rate was 81.2%: 75.5% in genotype 1 and 90.6% in genotype 2. For rs12979860, the frequencies of polymorphisms were 89% for the CC type, 11% for the CT type, and 0% for the TT type. Their overall SVR rate was 87% (39/47): 90.5% (38/42) for the CC type and 20% (1/5) for the CT type. For genotype 1, SVR rates were 88% (21/24) for the CC type and 0% (0/4) for the CT type. Multivariate analysis revealed that the IL28B-CC type was a good predictor for SVR.
The SVR of the combination therapy in Koreans was higher than that observed in Western countries. This finding might be attributable to the high prevalence of IL28B-CC type among Koreans, which may be a good predictor of SVR.
Clinical and molecular hepatology. 12/2012; 18(4):360-7.
[show abstract][hide abstract] ABSTRACT: Arsenic is a terribly poisonous material. There have been many reports of arsine poisoning in workers, and a few have discussed acute kidney injury by arsine. But literatures which investigated the pathologic findings are uncommon, and especially, the ones describing ultrastructural findings are rare. Here, we report an incident of acute arsine poisoning complicated by acute kidney injury and suggest the characteristics of the renal pathology in arsine-induced renal injury, especially the ultrastructural findings.
[show abstract][hide abstract] ABSTRACT: Pathogenesis of Parkinson's disease and related catecholaminergic neurological disorders is closely associated with changes in the levels of tyrosine hydroxylase (TH). Therefore, investigation of the regulation of the TH gene system should assist in understanding the pathomechanisms involved in these neurological disorders. To identify regulatory domains that direct human TH expression in the central nervous system (CNS), we generated two transgenic mouse lines in which enhanced yellow fluorescent protein (EYFP) is expressed under the control of either 3.2-kb (hTHP-EYFP construct) human TH promoter or 3.2-kb promoter with 2-kb 3'-flanking regions (hTHP-ex3-EYFP construct) of the TH gene. In the adult transgenic mouse brain, the hTHP-EYFP construct directs neuron-specific EYFP expression in various CNS areas, such as olfactory bulb, striatum, interpeduncular nucleus, cerebral cortex, hippocampus, and particularly dentate gyrus. Although these EYFP-positive cells were identified as mature neurons, few EYFP-positive cells were TH-positive neurons. On the other hand, we could detect the EYFP mRNA expression in a subset of neurons in the olfactory bulb, midbrain, and cerebellum, in which expression of endogenous TH is enriched, with hTHP-ex3-EYFP transgenic mice. These results indicate that the 3.2-kb sequence upstream of the TH gene is not sufficient for proper expression and that the 2-kb sequence from the translation start site to exon 3 is necessary for expression of EYFP in a subset of catecholaminergic neurons.
Journal of Neuroscience Research 06/2012; 90(10):1949-59. · 2.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: The measurement of glomerular filtration rate (GFR) applying serum creatinine (Cr) does not reflect the GFR of patients accurately, and thus recently, studies on the measurement of GFR applying serum cystatin-C (Cys-C) have been conducted. We investigated the relationship between Cys-C and proteinuria in patients with chronic kidney disease.
We compared the biochemical test, including serum Cys-C, the amount of proteinuria and the concentration of Cys-C measured by the 24-h urine test, and the difference of GFR on 105 patients who visited our hospital in 6 months (January to June 2007).
Among 105 patients, 58 patients were males, and the mean age was 56.74 ± 16.31 years. With regard to underlying diseases, the group with diabetes had 76 patients and the group showing nephrotic proteinuria [nephrotic syndrome (NS)] had 29 patients. The GFR-Cys-C in the NS group (44.17 ± 26.32 mL/min) was higher than in the non-NS group (33.68 ± 14.29 mL/min; p = 0.041). The fractional excretion (FE) of Cys-C increased according to FE of albumin ( p = 0.000) and GFR-modification of diet in renal disease (MDRD) equation (p = 0.000). Serum Cys-C increased according to corrected urine Cys-C (p = 0.010). The GFR calculated by serum Cys-C decreased according to FE of albumin (p = 0.003). The degree of difference between GFR-Cys-C and GFR-MDRD was negatively correlated according to the FE of albumin (p = 0.001).
We confirmed that urinary excretion of Cys-C could be altered by previously known mechanisms such as proteinuria. Difference between GFR-Cys-C and GFR-MDRD was negatively correlated according to FE of albumin.
[show abstract][hide abstract] ABSTRACT: Chemical doping can decrease sheet resistance of graphene while maintaining its high transparency. We report a new method to simultaneously transfer and dope chemical vapor deposition grown graphene onto a target substrate using a fluoropolymer as both the supporting and doping layer. Solvent was used to remove a significant fraction of the supporting fluoropolymer, but residual polymer remained that doped the graphene significantly. This contrasts with a more widely used supporting layer, polymethylmethacrylate, which does not induce significant doping during transfer. The fluoropolymer doping mechanism can be explained by the rearrangement of fluorine atoms on the graphene basal plane caused by either thermal annealing or soaking in solvent, which induces ordered dipole moments near the graphene surface. This simultaneous transfer and doping of the graphene with a fluoropolymer increases the carrier density significantly, and the resulting monolayer graphene film exhibits a sheet resistance of ∼320 Ω/sq. Finally, the method presented here was used to fabricate flexible and a transparent graphene electrode on a plastic substrate.
[show abstract][hide abstract] ABSTRACT: Patients with proteinuria frequently show changes in thyroid hormone levels. Serum T3 depression predicts a negative outcome in chronic kidney disease (CKD) patients and may be associated with cardiovascular complications or chronic inflammation. Few studies have explored the relationship between thyroid hormone dysregulation and clinical outcome in patients with proteinuria.
We reviewed thyroid function test results obtained from 211 patients with 24 h urinary protein excretion greater than 150 mg/day and found a correlation of thyroid hormone level with cardiovascular events and mortality.
T3 decreased with age (p = 0.001) and 24 h urine albumin (p = 0.028). Free T4 decreased in accordance with 24 h urine protein and serum creatinine (p = 0.034 and p = 0.033, respectively). In the Kaplan-Meier survival analysis, lower cumulative survival, higher cardiovascular events, and mortality were found in the low T3 group compared with the normal T3 group (p = 0.000, p = 0.013, and p = 0.001, respectively). In Cox regression analysis, we observed that, with low T3, decreased sodium, and old age, the incidence of cardiovascular complications (p = 0.000, p = 0.016, and p = 0.000, respectively), cardiovascular mortality (p = 0.000, p = 0.048, and p = 0.001, respectively), and all-cause mortality (p = 0.000, p = 0.017, and p = 0.000, respectively) increased.
In CKD patients with proteinuria, low T3 concentration predicted all-cause mortality and cardiovascular event independently of the severity of proteinuria.
[show abstract][hide abstract] ABSTRACT: Dual doping-driven perpendicular electric field with opposite directions remarkably increase the on/off current ratio of bilayer graphene field-effect transistors. This unambiguously proves that it is possible to open a bandgap with two molecular dopants (F4-TCNQ and NH(2) -functionalized self-assembled monolayers (SAMs)) even in a single-gate device structure.
[show abstract][hide abstract] ABSTRACT: Tyrosine hydroxylase (TH) is the first and rate-limiting enzyme in the biosynthesis of catecholamines, and its expression is regulated in a developmental stage- and cell type-specific manner. Our previous work suggested that the genetic elements responsible for cell type-specific expression of TH were in the repressor region of the TH promoter between -2187 and -1232 bp. To investigate the molecular mechanisms underlying the specificity of TH expression, the DNA methylation patterns of the CpG islands in the repressor region of the TH promoter were examined in human neural stem cells (NSCs) and dopaminergic neuron-like cells. Using a bisulfite sequencing method, we found that the cytosine residues of CpG islands within the NRSE-R site were specifically methylated in NSCs, but not in SH-SY5Y neuroblastoma cells. In NSCs, CpG methylation correlated with reduced TH gene expression, and inhibition of DNA methylation with 5-azacytidine restored TH expression. Furthermore, methyl-CpG binding domain proteins (MBDs) bound to the highly methylated X-1 and X-2 regions of the TH gene in NSCs. Taken together, these results suggest that region-specific methylation and MBDs play important roles in TH gene regulation in NSCs.
Biochemical and Biophysical Research Communications 11/2011; 414(4):712-8. · 2.41 Impact Factor