Jae Hoon Moon

The impact of anode microstructure on the power generating characteristics of SOFC

It is normally required that the anode materials should have high electrical conductivity and gas permeability to reduce the polarization loss of the cell. In this study, we made anode substrates of SOFC with two different methods, which resulted in different anode microstructures, especially different pore structures. We investigated the effect of microstructure of anode substrate on the unit cell performance in terms of its electrical conductivity, gas permeability and power-generating characteristics. According to the analysis, the anode substrate with higher inactive pore volume resulted in significantly reduced cell performance by decreasing the number of electrical conduction paths, the effective gas diffusion paths and the electrochemically active sites for the anodic reaction.

The role of ultrasound findings in the management of thyroid nodules with atypia or follicular lesions of undetermined significance

Atypia or follicular lesions of undetermined significance (AUS/FLUS) is a broad cytological category in the Bethesda system for classifying thyroid cytology. This study investigated the diagnostic accuracy of ultrasound (US) analysis of thyroid nodules with AUS/FLUS.

Tsc-22 enhances TGF-β signaling by associating with Smad4 and induces erythroid cell differentiation

Tsc-22 was isolated as a TGF-β-inducible gene by differential screening of the mouse osteoblastic cell cDNA library [J Biol Chem 267 (1992) 10219]. tsc-22 mRNA is expressed in almost all organs of mice and humans and its expression is induced in a variety of cell lines by many different factors including TGF-β, phorbol ester, serum, and progestin. tsc-22 encodes a 18-kd protein that contains a leucine zipper motif and a Tsc-box. The leucine zipper motif of the Tsc-22 protein does not have a basic DNA binding motif and when the protein was fused to a heterologous DNA binding domain, it showed various transcription-modulating activities ranging from activation to repression [J Biol Chem 274 (1999) 27439, Biochem Biophys Res Commun 278 (2000) 659]. Although these results suggest that the Tsc-22 protein functions as a transcriptional regulator recruiting various coactivators or repressors, its mechanism is not known. In this study, we examined whether Tsc-22 modulates the TGF-β-dependant signaling pathway and found that Tsc-22 binds to and modulate the transcriptional activity of Smad3 and Smad4. Its effect on cellular differentiation was also examined. (Mol Cell Biochem 271: 23–28, 2005)

Prognostic effects of TERT promoter mutations are enhanced by coexistence with BRAF or RAS mutations and strengthen the risk prediction by the ATA or TNM staging system in differentiated thyroid cancer patients.

Recent reports suggest that mutations in the promoter of the gene encoding telomerase reverse transcriptase (TERT) affect thyroid cancer outcomes.

Thyroglobulin in Washout Fluid From Lymph Node Fine-needle Aspiration Biopsy in Papillary Thyroid Cancer: Large-scale Validation of the Cutoff Value to Determine Malignancy and Evaluation of Discrepant Results

CONTEXT There are still some controversies regarding the cutoff value and the influential factors of thyroglobulin (Tg) concentration in washout fluid from fine-needle aspiration (FNA) biopsy (FNA-Tg) on cervical lymph nodes (LNs) in patients with papillary thyroid cancer (PTC). OBJECTIVE Our aims were to validate the cutoff value of FNA-Tg in diagnosing malignant LNs on a large scale and to investigate the influential factors that could result in the discrepancy between the final diagnosis and FNA-Tg. DESIGN, SETTING, AND PARTICIPANTS We conducted a retrospective cohort study based on hospital records with 528 cases of FNA-Tg measurement from 419 PTC patients. MAIN OUTCOME MEASURE The cutoff value of FNA-Tg was obtained from receiver operating characteristic analysis with final diagnosis. Binary logistic regression analysis was performed to investigate the influential factors. RESULTS In the final diagnosis, 190 LNs were malignant, and 338 LNs were benign. The median FNA-Tg was 521.2 (3676.8) ng/mL in malignant LNs, and 0.1 (0.2) ng/mL in benign LNs. The optimal cutoff value of FNA-Tg in distinguishing malignant LNs from benign LNs was 1.0 ng/mL (sensitivity, 93.2%; specificity, 95.9%) in all cases. Combining FNA-Tg and FNA cytology showed superior diagnostic power (sensitivity, 98.4%; specificity, 94.4%) when compared with diagnostic strategy using either FNA cytology or FNA-Tg alone. FNA-Tg, serum TSH, and serum Tg were higher in nonthyroidectomized patients than in thyroidectomized patients (P < .001, respectively). FNA-Tg was correlated with serum TSH and Tg levels (P < .001, respectively), and binary logistic regression analysis showed that serum TSH suppression and serum Tg presence independently affected the diagnosis made by FNA-Tg. CONCLUSIONS Our results validated 1.0 ng/mL of FNA-Tg as a cutoff value for diagnosing LN metastasis of PTC and suggested that serum TSH suppression and serum Tg presence should be considered in diagnosing LN malignancy with FNA-Tg in PTC patients.

Epicardial adipose tissue thickness is an indicator for coronary artery stenosis in asymptomatic type 2 diabetic patients: its assessment by cardiac magnetic resonance.

BackgroundWe used cardiovascular magnetic resonance (CMR) to investigate the association between epicardial adipose tissue (EAT) thickness and silent myocardial ischemia, as well as coronary artery stenosis, in asymptomatic type 2 diabetic patients.MethodsThe study included 100 type 2 diabetic subjects (51 male and 49 female; mean age: 56 ± 7 years). Silent myocardial ischemia, as determined by CMR, was defined as evidence of inducible ischemia or myocardial infarction. Signal reduction or stenosis of ≥ 50% in the vessel diameter was used as the criteria for significant coronary artery stenosis on coronary magnetic resonance (MR) angiography.ResultsEAT thickness was positively correlated with body mass index (BMI), waist-to-hip ratio, systolic blood pressure, postprandial glucose, fasting/postprandial triglyceride (TG), serum glycated hemoglobin (HbA1c) level, and homeostasis model assessment of insulin resistance (HOMA-IR) score. Significant coronary artery stenosis was found in 24 patients, while 14 patients had silent myocardial ischemia in CMR (1 with silent myocardial infarction, 11 with inducible ischemia, and 2 with both). EAT thickness was greater in patients who had coronary artery stenosis (13.0 ± 2.6 mm vs. 11.5 ± 2.1 mm, p = 0.01), but did not differ between the subjects with or without silent myocardial ischemia on CMR images (12.8 ± 2.1 vs. 11.7 ± 2.3 mm, p = 0.11). Multivariate logistic regression analysis indicated that EAT thickness was an independent indicator for significant coronary artery stenosis after adjusting for traditional risk factors (OR 1.403, p = 0.026).ConclusionsIncreased EAT thickness assessed by CMR is an independent risk factor for significant coronary artery stenosis in asymptomatic type 2 diabetes. However, EAT thickness was not associated with silent myocardial ischemia.

Thyroid “Atypia of undetermined significance” with nuclear atypia has high rates of malignancy and BRAF mutation

“Atypia of undetermined significance” (AUS) in the Bethesda System for Reporting Thyroid Cytopathology is a heterogeneous category for cases that cannot be easily classified into benign, suspicious, or malignant. This study evaluated whether cytomorphology‐based subcategorization could better predict the malignancy risk in cases designated as AUS, and how the subcategories correlated with BRAF mutation status in thyroid fine‐needle aspirates (FNA).

Up-regulation of hepatic low-density lipoprotein receptor-related protein 1: a possible novel mechanism of antiatherogenic activity of hydroxymethylglutaryl-coenzyme A reductase inhibitor Atorvastatin and hepatic LRP1 expression.

Low-density lipoprotein receptor-related protein 1 (LRP1) binds to apolipoprotein E and serves as a receptor for remnant lipoproteins in the liver, thus playing an important role in clearing these atherogenic particles. In this study, we investigated the effect of atorvastatin, a hydroxymethylglutaryl-coenzyme A reductase inhibitor, on hepatic LRP1 expression. We used HepG2 and Hep3B cells for in vitro study, and Otsuka Long-Evans Tokushima fatty and Sprague-Dawley rats for in vivo study. We used relatively high pharmacologic dose of atorvastatin in this study (in vitro, 0.5 μmol/L in culture media, for 48 hours; in vivo, 20 mg/[kg d], for 6 weeks). Atorvastatin increased LRP1 and low-density lipoprotein (LDL) receptor expression in HepG2 and Hep3B cells and induced hepatic LRP1 and LDL receptor expression in chow diet-fed Sprague-Dawley rats and high-fat diet-fed Otsuka Long-Evans Tokushima fatty rats. Atorvastatin decreased intracellular sterol level and increased the amount of the nuclear form of sterol response element-binding protein-2 (SREBP-2) in both HepG2 and Hep3B cells as well as in two animal models. Treatment of HepG2 cells with LDL increased intracellular sterol level and reduced LRP1, LDL receptor, and SREBP-2. When SREBP-2 in HepG2 cells was knocked down by small interfering RNA, the induction of LRP1 expression by atorvastatin did not take place. In conclusion, up-regulation of hepatic LRP1 might be a novel mechanism by which statin treatment decreases remnant lipoproteins. In addition, SREBP-2 acts as a mediator of atorvastatin-induced up-regulation of hepatic LRP1. Future studies using standard doses of atorvastatin in humans are needed to elucidate clinical relevance of these findings.

Interactions Between Dietary Calcium Intake and Bone Mineral Density or Bone Geometry in a Low Calcium Intake Population (KNHANES IV 2008–2010)

CONTEXT Little is known about the interactions between dietary calcium intake and bone strength parameters in populations or areas with low calcium intake. OBJECTIVE The objective of the study was to investigate the relationship between dietary calcium intake and bone mineral density (BMD) or bone geometry in an Asian population with low calcium intake. DESIGN AND SETTING This was a cross-sectional study of data from the Korea National Health and Nutrition Examination Survey, 2008-2010. PARTICIPANTS A total of 3448 men and 3812 women older than 50 years were stratified by daily dietary calcium intake: less than 400 mg/d, 400-799 mg/d, 800-1199 mg/d, and 1200 mg/d or greater. MAIN OUTCOME MEASURES BMD was measured by dual-energy X-ray absorptiometry and the geometric index was calculated. RESULTS Mean daily calcium intake was 470 mg/d in this population. BMD in the lumbar spine (both sexes) and femoral neck (women) was significantly lower only when calcium intake was less than 400 mg/d. In men, femoral neck and total hip BMD was positively related to calcium intake up to 1200 mg/d. Calcium intake less than 400 mg/d was negatively related to femoral cortical thickness and buckling ratio. These interactions disappeared when the 25-hydroxyvitamin D level was 30 ng/mL or greater in men and 20 ng/mL or greater in women. CONCLUSIONS Low calcium intake was significantly related with low BMD and increased risk of osteoporosis. However, the association between calcium and BMD was not consistently linear, and a sufficient vitamin D level appears to compensate for the negative influences of low calcium intake on bone.

The diagnosis and management of hyperthyroidism in Korea: consensus report of the korean thyroid association.

Hyperthyroidism is one of the causes of thyrotoxicosis and the most common cause of hyperthyroidism in Korea is Graves disease. The diagnosis and treatment of Graves disease are different according to geographical area. Recently, the American Thyroid Association and the American Association of Clinical Endocrinologists suggested new management guidelines for hyperthyroidism. However, these guidelines are different from clinical practice in Korea and are difficult to apply. Therefore, the Korean Thyroid Association (KTA) conducted a survey of KTA members regarding the diagnosis and treatment of hyperthyroidism, and reported the consensus on the management of hyperthyroidism. In this review, we summarized the KTA report on the contemporary practice patterns in the diagnosis and management of hyperthyroidism, and compared this report with guidelines from other countries.