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Dive into the research topics where Jong Ryeal Hahm is active.

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Featured researches published by Jong Ryeal Hahm.


Thyroid | 2001

Routine Measurement of Serum Calcitonin is Useful for Early Detection of Medullary Thyroid Carcinoma in Patients with Nodular Thyroid Diseases

Jong Ryeal Hahm; Myung-Shik Lee; Yong-Ki Min; Moon-Kyu Lee; Kwang-Won Kim; Seok Jin Nam; Jung-Hyun Yang; Jae Hoon Chung

BACKGROUND Medullary thyroid carcinoma (MTC) is characterized by a high concentration of serum calcitonin. Routine measurement of serum calcitonin concentration has been advocated for detection of MTC among patients with nodular thyroid diseases. However, a minimal to moderate increase of serum calcitonin concentration has been frequently observed in diseases other than MTC. Fine-needle aspiration cytology (FNAC) is not a reliable method for detection of MTC. Therefore, we evaluated the usefulness of routine measurement of serum calcitonin concentration in patients with nodular thyroid diseases, and studied the validity of pentagastrin stimulation test and FNAC in these patients. SUBJECTS AND METHODS We performed routine measurement of serum calcitonin concentrations in 1,448 patients (male, 285, female, 1,163) with nodular thyroid diseases. The average age was 46 years (range, 14-86 years). Initial examination included thyroid examination, thyroid scan or ultrasonography, measurements of serum free triiodothyronine) (T3), free thyroxine (T4), thyrotropin (TSH) levels, and antithyroid autoantibodies. FNAC was performed in all patients who had palpable or visible thyroid nodule by ultrasonography, and pentagastrin stimulation test was performed in 39 patients who consented. Serum calcitonin concentration was measured with a two-site immunoradiometric assay using commercial kits. We also measured the serum calcitonin concentration in 407 healthy subjects without thyroid or nonthyroid diseases. RESULTS Serum calcitonin concentration was 10 pg/mL or less in 403 normal subjects (99.0 percentile), and 11-13 pg/mL in the remaining 4 subjects. We found that 56 (3.87%) of 1,448 patients with nodular thyroid diseases had serum calcitonin level above 10 pg/mL. Ten patients (0.69%) with histologically confirmed MTC were detected by the routine measurement of serum calcitonin. The prevalence of MTC was 5.2% in 194 patients with thyroid carcinoma. Five of 10 patients with MTC had basal serum calcitonin level above 100 pg/mL. The remaining 5 patients had minimal or moderate elevation of basal serum calcitonin (range, 12-86 pg/mL). Serum calcitonin concentration increased to more than 100 pg/mL by pentagastrin in all patients with MTC (2.4- to 37.7-fold increase). FNAC suggested MTC in only 2 patients (22.2%), and failed to diagnose MTC in 7 patients. FNAC was not performed in 1 patient with MTC, because he had no visible mass by ultrasonography. CONCLUSION These results suggested that routine measurement of serum calcitonin is useful in the early detection of MTC among patients with nodular thyroid diseases. Pentagastrin stimulation test may also be a reliable way for evaluating thyroid nodular patients with mild or moderate elevation of serum calcitonin concentrations. However, FNAC was not sensitive in detecting MTC. We recommend routine measurement of serum calcitonin concentration in patients with nodular thyroid diseases.


Cancer Letters | 2012

Cathepsin D inhibits oxidative stress-induced cell death via activation of autophagy in cancer cells

Young-Sool Hah; Hae Sook Noh; Ji Hye Ha; Jin Sook Ahn; Jong Ryeal Hahm; Hee Young Cho; Deok Ryong Kim

Cathepsin D (CatD), a lysosomal aspartic protease, plays an essential role in tumor progression and apoptosis. However, the function of CatD in cell death is not yet fully understood. In this study, we identified CatD as one of up-regulated proteins in human malignant glioblastoma M059J cells that lack the catalytic subunit of DNA-PK compared with its isogenic M059K cells with normal DNA-PK activity. M059J cells were relatively more resistant to genotoxic stress than M059K cells. Overexpression of wild-type CatD but not catalytically inactive mutant CatD (D295N) inhibited H(2)O(2)-induced cell death in HeLa cells. Furthermore, knockdown of CatD expression abolished anti-apoptotic effect by CatD in the presence of H(2)O(2). Interestingly, high expression of CatD in HeLa cells significantly activated autophagy: increase of acidic autophagic vacuoles, LC3-II formation, and GFP-LC3 puncta. These results suggest that CatD can function as an anti-apoptotic mediator by inducing autophagy under cellular stress. In conclusion, inhibition of autophagy could be a novel strategy for the adjuvant chemotherapy of CatD-expressing cancers.


Liver International | 2012

α‐lipoic acid prevents non‐alcoholic fatty liver disease in OLETF rats

Tae Sik Jung; Soo Kyoung Kim; Hyun Joo Shin; Byeong Tak Jeon; Jong Ryeal Hahm; Gu Seob Roh

Insulin resistance, oxidative stress, inflammation and innate immune system activation contribute to the development of non‐alcoholic fatty liver disease (NAFLD) through steatosis and inflammation in the liver. The powerful antioxidant α‐lipoic acid (ALA) has been shown to improve insulin sensitivity and suppress inflammatory responses. This study explores how ALA administration protects against NAFLD.


Clinica Chimica Acta | 2002

Measurement of corticoids in the patients with clinical features indicative of mineralocorticoid excess

Man Ho Choi; Jong Ryeal Hahm; Byung Hwa Jung; Bong Chul Chung

BACKGROUND A method for the measurement of five important serum and urinary corticoids on the syndrome of mineralcorticoid excess is reported. The methodology was combined gas chromatography-mass spectrometry (GC-MS) with selected ion-monitoring mode. METHODS After extraction with a solid-phase cartridge using an Oasis HLB copolymer, the residues were derivatized with a mixture of N-methyl-N-trimethylsilyltrifluoroacetamide/ammonium iodide/dithioerythritol (1000:4:5, v/w/w), and analyzed. RESULTS The linearity as the regression coefficients were >0.979 over a range of 1-500 ng/ml, and limit of detection ranged from 1 to 3 ng/ml while their analytical recoveries varied in the range of 75.7-94.9%. The overall precision (% CV) of the method were 3.2-7.2% and 3.6-6.3% for serum and urine, respectively. The accuracy expresses as % bias ranged from -4.1 to 6.4%. This assay was used on two patients with hypokalemic hypertension, and may be useful in ruling out mineralcorticoid excess (AME) type 1 or 2. CONCLUSIONS The present GC-MS technique may be useful to differentiate between the syndrome of AME and other hypertensive diseases with clinical features suggestive of mineralcorticoid excess because of the assays reliablity and precision.


Diabetes, Obesity and Metabolism | 2005

Fermented mushroom milk‐supplemented dietary fibre prevents the onset of obesity and hypertriglyceridaemia in Otsuka Long‐Evans Tokushima fatty rats

B. S. Jeon; Jeong-Won Park; B. K. Kim; Ho-Su Kim; Tae Sik Jung; Jong Ryeal Hahm; Deok Ryong Kim; Young-Su Cho; J. Y. Cha

Aim:  Fermented milk product containing edible mushroom water extracts (mushroom yogurt; MY) has been reported to have glycaemic control and triglyceride‐lowering effects in streptozotocin (STZ)‐induced diabetic rats and Zucker diabetic fatty (ZDF) rats. Here, we investigated how MY‐supplemented dietary fibre (10 and 20%, v/w) influences the onset of obesity and hypertriglyceridaemia in Otsuka Long‐Evans Tokushima fatty (OLETF) rats.


Yonsei Medical Journal | 2008

Rituximab-CHOP Induced Interstitial Pneumonitis in Patients with Disseminated Extranodal Marginal Zone B Cell Lymphoma

Kwang Min Kim; Ho Cheol Kim; Kyung-Nyeo Jeon; Hoon-Gu Kim; Jung Hun Kang; Jong Ryeal Hahm; Gyeong-Won Lee

A 69-year-old male was diagnosed in February 2004 with stage IV extranodal marginal zone B cell lymphoma involving the mediastinal nodes, lung parenchyma and bone marrow with high LDH. Shortness of breath developed following the 5th course of Rituximab-CHOP chemotherapy (cyclophosphamide, Vincristine, Doxorubicin, Prednisolone). Bronchoscopy guided transbronchial lung biopsy revealed interstitial thickening and type II pneumocyte activation, compatible with interstitial pneumonitis. After treatment with prednisolone a complete resolution of the dyspnea was observed. The patient was well on routine follow-up at the outpatient clinic, with no progression of lymphoma or interstitial pneumonitis.


Cell Biology and Toxicology | 2012

Mitigation of H2O2-induced autophagic cell death by propofol in H9c2 cardiomyocytes

Ji Hye Ha; Hae Sook Noh; Il Woo Shin; Jong Ryeal Hahm; Deok Ryong Kim

Autophagy, a self-eating process, is responsible for degradation of long-lived proteins and damaged cellular proteins/organelles. Double-membrane autophagosomes, formed during the process, engulf proteins/organelles and fuse with lysosomes to degrade the contents. It is important to maintain cell homeostasis and many physiological processes including cellular responses to oxidative stress. Oxidative stress induced by myocardial infarction is a major factor of heart failures. In this study, we examined how propofol modulates hydrogen peroxide (H2O2)-induced autophagic cell death in H9c2 cardiomyocytes. H2O2 dramatically induced cell death, which was similarly reduced in the presence of either propofol or autophagy inhibitors (e.g., wortmannin), suggesting that propofol has a protective effect in H2O2-induced autophagic cell death. Acidic autophagic vacuoles were elevated in H2O2-treated H9c2 cells, but they were largely decreased in the presence of propofol. Furthermore, many autophagy-related proteins such as LC3-II, ATG proteins, p62, AMPK, and JNK were activated in H2O2-treated H9c2 cells and were significantly deactivated in the presence of propofol. These results show that propofol regulates oxidative stress-induced autophagic cell death in cardiomyocytes. We further suggest that propofol can act as a cardioprotectant in heart diseases.


Diabetes & Metabolism Journal | 2012

Clinical Significance of the Presence of Autonomic and Vestibular Dysfunction in Diabetic Patients with Peripheral Neuropathy

Soo Kyoung Kim; Kyeong Ju Lee; Jong Ryeal Hahm; Sang Min Lee; Tae Sik Jung; Jung Hwa Jung; Sungsu Kim; Deok Ryong Kim; Seong-Ki Ahn; Won-Hee Choi; Soon Il Chung

Background We investigated the prevalence of diabetic autonomic neuropathy (DAN) and vestibular dysfunction (VD) in diabetic patients with peripheral neuropathy. Methods Thirty-five diabetic patients with peripheral neuropathy were enrolled from August 2008 to July 2009. All subjects underwent autonomic function tests. Nineteen of the patients (54.3%) underwent videonystagmography. Results Diabetic autonomic neuropathy was observed in 28 patients (80%). A mild degree of autonomic failure was observed in 18 patients (64.3%), and a moderate degree of autonomic failure was observed in ten patients (35.7%). Factors related to DAN included diabetic nephropathy (P=0.032), degree of chronic kidney disease (P=0.003), and duration of diabetes (P=0.044). Vestibular dysfunction was observed in 11 of 19 patients (57.9%). There was no significant association between DAN and VD. Conclusion Diabetic autonomic neuropathy was observed in 28 diabetic patients (80%) with peripheral neuropathy. Vestibular dysfunction was observed in nearly 60% of diabetic patients with peripheral neuropathy who complained of dizziness but showed no significant association with DAN. Diabetic patients who complained of dizziness need to examine both autonomic function and vestibular function.


Lung Cancer | 2008

Combination chemotherapy with irinotecan and cisplatin in elderly patients (≥65 years) with extensive-disease small-cell lung cancer

Hoon-Gu Kim; Gyeong-Won Lee; Jung Hun Kang; Myung-Hee Kang; In-Gyu Hwang; Seok Hyun Kim; Jong Ryeal Hahm; Yi Yeong Jeong; Ho Cheol Kim; Jong Duk Lee; Jongseok Lee; Young Sil Hwang

INTRODUCTION Combination chemotherapy with irinotecan and cisplatin is one of the standard treatments for patients with small-cell lung cancer (SCLC). In elderly patients, however, its efficacy and toxicity has not been well documented. In this Phase II study, we assessed the efficacy and toxicity of combination chemotherapy with irinotecan and cisplatin and examined whether advanced age compromises it in elderly patients with previously untreated extensive-disease small-cell lung cancer (ED-SCLC). METHODS In this study, 46 previously untreated elderly patients (65 years or older) with ED-SCLC were given combination chemotherapy consisting of irinotecan 60 mg/m(2) on days 1, 8 and 15 and cisplatin 60 mg/m(2) on day 1. The treatment was repeated every 4 weeks until patients completed the maximum six cycles. RESULTS Patients consisted of 37 men and 9 women, whose median age was 70 years (range 65-81 years). A complete response and a partial response were observed in 19.6% (9/46) and 56.5% (26/46), respectively. The overall response rate was 76.1% (95% C.I; 63.8-88.4%). The overall median survival was 10.4 months (range 7.6-13.2 months). The median progression-free survival was 8.32 months (range 6.8-9.8 months). Major toxicities included neutropenia (grade 3-4, 58.7%), leukopenia (grade 3-4, 49.9%), infection (grade 3-4, 39.1%) and diarrhea (grade 3-4, 30.4%). Incidence of febrile neutropenia was significantly higher in patients with ECOG performance status 2-3 compared with ECOG performance status 0-1 (70.4% vs. 5.2%; p<0.001). There were two treatment related deaths in patients ECOG performance status 3. CONCLUSIONS Our results indicate that combination chemotherapy with irinotecan and cisplatin is an effective treatment for elderly patients with ED-SCLC who have good ECOG performance status and physicians should be aware of the mortality and morbidity due to myelosuppression following this treatment in elderly ED-SCLC patients with poor ECOG performance status.


Life Sciences | 2014

Alpha-lipoic acid attenuates adipocyte differentiation and lipid accumulation in 3T3-L1 cells via AMPK-dependent autophagy.

Jong Ryeal Hahm; Hae Sook Noh; Ji Hye Ha; Gu Seob Roh; Deok Ryong Kim

AIMS During the adipocyte differentiation, some intracellular organelles are degraded and instead lipid droplets are gradually accumulated in the cytoplasm for energy storage. Autophagy, a self-eating process, has been implicated in the removal of intracellular components in adipogenesis, but its mechanism is poorly understood. In this work we examined how α-lipoic acid modulates the autophagic process during the adipocyte differentiation. MAIN METHODS 3T3-L1 pre-adipocytes were differentiated in the medium containing insulin, dexamethasone, and 1-methyl-3-isobutylxanthine. Lipid contents in adipocytes were determined by Oil-Red O staining. Autophagy was evaluated by Western blotting, accumulation of acidic vacuoles in cells. KEY FINDINGS We observed that formation of LC3-II, an indicative marker for autophagy, was greatly down-regulated at the beginning stage of differentiation, but it was gradually increased with respect to earlier differentiation time. In addition, ATG5-12 conjugates were similarly produced, and acidic autophagic vacuoles were greatly elevated at the earlier stages of differentiation. Furthermore, α-lipoic acid deteriorated the intracellular accumulation of lipid droplets by blocking the production of acidic autophagic vacuoles, LC3-II, and other autophagy-related proteins during the adipocyte differentiation and influenced expression of adipocyte-stimulating factors. It also specifically suppressed activation of AMPK, an essential modulator for autophagy, at the earlier step of adipocyte differentiation. SIGNIFICANCE These data suggest that α-lipoic acid significantly attenuates adipocyte differentiation via the direct modulation of intracellular degradation process and consequently decrease intracellular fat deposit of adipocytes.

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Jung Hwa Jung

Gyeongsang National University

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Soo Kyoung Kim

Gyeongsang National University

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Tae Sik Jung

Gyeongsang National University

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Deok Ryong Kim

Gyeongsang National University

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Soon Il Chung

Gyeongsang National University

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Jaehoon Jung

Gyeongsang National University

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Sungsu Kim

Gyeongsang National University

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Sang Min Lee

Gyeongsang National University

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Bo Ra Kim

Gyeongsang National University

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Gyeong-Won Lee

Gyeongsang National University

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