Do-Hoon Kim

Samsung Medical Center, Seoul, Seoul, South Korea

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Publications (11)21.47 Total impact

  • Article: Endobronchial metastases from extrathoracic malignancy.
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    ABSTRACT: Purpose: Endobronchial metastasis is defined as documented extrathoracic malignancies metastatic to the endobronchus within a bronchoscopically visible range. Although the clinical and radiologic findings of endobronchial metastasis are similar to primary lung cancer, treatment and prognosis may be different. We hereby investigated the clinical, radiologic and bronchoscopic aspects of endobronchial metastases (EBM) in Korean patients. Materials and Methods: A total of 43 patients with EBM who underwent bronchoscopic biopsies from June 1991 to December 2009 at Severance Hospital, Yonsei University College of Medicine in Seoul, Korea, were analyzed retrospectively. We evaluated clinical, radiologic and bronchoscopic characteristics of EBM. Results: The patients consisted of 27 males and 16 females and their ages ranged from 18 to 77 years. The common primary cancers related to EBM were rectal (16.3%), colon (11.6%), breast (9.3%) and uterine (9.3%) cancers. The mean interval from diagnosis of primary cancer to EBM was 36 months, and the mean survival duration from diagnosis of EBM was 16.1 months in 33 deceased patients. Conclusion: EBM develop in various types of malignancies at various times with unremarkable manifestations. Therefore, physicians should consider the possibility of EBM, especially if a patient has a history of any malignancy, regardless of respiratory symptoms. Respiratory symptoms related with EBM can be treated by various safe procedures.
    Yonsei medical journal 03/2013; 54(2):403-9. · 0.77 Impact Factor
  • Article: 25-Hydroxyvitamin D insufficiency is associated with cardiometabolic risk in Korean adolescents: the 2008-2009 Korea National Health and Nutrition Examination Survey (KNHANES).
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    ABSTRACT: OBJECTIVE: Vitamin D insufficiency is known to be related to cardiometabolic disorders; however, the associations among serum 25-hydroxyvitamin D (25(OH)D) concentration and metabolic syndrome and cardiometabolic risk factors in children and adolescents have not yet been clearly delineated. For this reason, we investigated the relationship among serum 25(OH)D concentration and metabolic syndrome and cardiometabolic risk factors among Korean adolescents. DESIGN: We performed a cross-sectional analysis and used hierarchical multivariate logistic regression analysis models to adjust for confounding variables. SETTING: We used the data gathered during the 2008-2009 Korea National Health and Nutrition Examination Survey (KNHANES). SUBJECTS: Our subjects included 1504 Korean adolescents aged 12-18 years who participated in the KNHANES. RESULTS: Vitamin D insufficiency, defined as 25(OH)D concentration <50 nmol/l, was found in 75·3 % of Korean adolescents and was associated with an increased risk of the prevalence of metabolic syndrome. Waist circumference and BMI were the most closely correlated cardiometabolic components of metabolic syndrome according to serum 25(OH)D status, but no significant relationship was found between serum 25(OH)D concentration and insulin resistance or for the risks for high blood pressure, hyperglycaemia, reduced HDL-cholesterol or hypertriacylglycerolaemia, with or without adjustment for confounding variables. CONCLUSIONS: Low serum 25(OH)D concentration appears to be associated with several cardiometabolic risk factors and an increased risk of the prevalence of metabolic syndrome in Korean adolescents.
    Public Health Nutrition 11/2012; · 2.17 Impact Factor
  • Article: Estimate of a predictive cut-off value for serum 25-hydroxyvitamin D reflecting abdominal obesity in Korean adolescents.
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    ABSTRACT: Vitamin D deficiency is a serious global issue. Although the serum 25-hydroxyvitamin D [25(OH)D] test is generally the most accurate way to assess vitamin D levels, the optimal range of 25(OH)D has yet to be established. Moreover, the optimal level may vary according to race, region, and age. Suboptimal vitamin D status is associated with obesity and metabolic syndrome, which are the major risk factors for cardiovascular disorders; however, these relationships in children and adolescents have yet to be clearly determined. Therefore, we identified the best predictive cut-off value for reflecting abdominal obesity and, based on this value, we investigated the relationship between suboptimal 25(OH)D status and the risk for having abdominal obesity, being overweight or obese, and having metabolic syndrome in Korean adolescents. We performed a cross-sectional analysis of 713 Korean adolescents, between 12-19 years of age, and used data collected from the 2008 Korea National Health and Nutrition Examination Survey (KNHANES). Receiver operation characteristic curve analysis was used to identify the cut-off value that reflected abdominal obesity. The cut-off value of serum 25(OH)D that reflected abdominal obesity in Korean adolescents was 17.6 ng/mL. After making adjustments for gender, age, and regular physical exercise, the group that had lower levels of serum 25(OH)D compared to the cut-off value had a significantly higher risk for abdominal obesity, obesity, and metabolic syndrome than the group with 25(OH)D levels higher than the cut-off value. Suboptimal vitamin D status based on this value is associated with increased risk for abdominal obesity, obesity, and metabolic syndrome among Korean adolescents.
    Nutrition research (New York, N.Y.) 06/2012; 32(6):395-402. · 1.20 Impact Factor
  • Article: Inhibition of autoimmune diabetes by TLR2 tolerance.
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    ABSTRACT: We have reported that apoptotic β cells undergoing secondary necrosis, called "late apoptotic (LA) β cells," stimulated APCs and induced diabetogenic T cell priming through TLR2, which might be one of the initial events in autoimmune diabetes. Indeed, diabetogenic T cell priming and the development of autoimmune diabetes were significantly inhibited in TLR2-null NOD mice, suggesting the possibility that TLR2 blockade could be used to inhibit autoimmune diabetes. Because prolonged TLR stimulation can induce TLR tolerance, we investigated whether repeated TLR2 administration affects responses to LA β cells and inhibits autoimmune diabetes in NOD mice by inducing TLR2 tolerance. Treatment of primary peritoneal macrophages with a TLR2 agonist, Pam3CSK(4), suppressed cytokine release in response to LA insulinoma cells or further TLR2 stimulation. The expression of signal transducer IRAK-1 and -4 proteins was decreased by repeated TLR2 stimulation, whereas expression of IRAK-M, an inhibitory signal transducer, was enhanced. Chronic Pam3CSK(4) administration inhibited the development of diabetes in NOD mice. Diabetogenic T cell priming by dendritic cells and upregulation of costimulatory molecules on dendritic cells by in vitro stimulation were attenuated by Pam3CSK(4) administration in vivo. Pam3CSK(4) inhibited diabetes after adoptive transfer of diabetogenic T cells or recurrence of diabetes after islet transplantation by pre-existing sensitized T cells. These results showed that TLR2 tolerance can be achieved by prolonged treatment with TLR2 agonists, which could inhibit priming of naive T cells, as well as the activity of sensitized T cells. TLR2 modulation could be used as a novel therapeutic modality against autoimmune diabetes.
    The Journal of Immunology 11/2011; 187(10):5211-20. · 5.79 Impact Factor
  • Article: Role of TLR2 in the pathogenesis of autoimmune diabetes and its therapeutic implication.
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    ABSTRACT: Recently, a couple of articles suggested the possibility that apoptosis of pancreatic β-cells induces inflammatory/immune responses to β-cells. Such a theory is based on the assumption that apoptotic cells can, under certain circumstances, induce immune responses, inflammatory and autoimmune disorders, which is in contrast to the dogma that apoptotic cells result in immunosuppression and necrotic cells provoke inflammation/immunity. We observed that late apoptotic β-cells with secondary necrosis elicited inflammatory responses in macrophages through the toll-like receptor 2 (TLR2)/MyD88/nuclear factor-κB signalling pathway. Late apoptotic cells also induced TLR2-dependent maturation of dendritic cells and then activation of autoreactive T-cells. TLR2 knockout mice showed defective priming of diabetogenic T-cells by apoptotic β-cells in the pancreatic lymph nodes. Furthermore, TLR2 deficiency conferred a significant protection against type 1 diabetes (T1D) and insulitis in T1D animal models. These findings present evidence suggesting that apoptosis of pancreatic β-cells could be one of the initial events in T1D and provide a novel strategy for therapeutic or preventive intervention in T1D.
    Diabetes/Metabolism Research and Reviews 11/2011; 27(8):797-801. · 3.37 Impact Factor
  • Article: An increase in serum uric acid concentrations is associated with an increase in the Framingham risk score in Korean adults.
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    ABSTRACT: Uric acid is a novel cardiovascular disease (CVD) factor, but its use as an independent risk factor for CVD remains controversial. Here, we examined the correlation between Framingham risk score (FRS) and serum uric acid concentrations in asymptomatic Korean adults. This cross-sectional study was performed on 8035 Korean adults. Besides FRS, we measured body mass index, fasting blood glucose, homeostasis model assessment of insulin resistance, creatinine, γ-glutamyltransferase, the lipid profile, uric acid, high-sensitive C-reactive protein, and the white blood cell count. All subjects were placed into one of three risk groups according to their FRS. All CVD related factors were significantly different in the three FRS groups. The increments of uric acid increased significantly FRS from the 10-year risk 0%-9% group to the >10% group after adjusting for other CVD-related factors using ordinal logistic regression analysis. Analyses of the three age groups showed similar effects. An increased uric acid concentration is associated with an increase in coronary heart disease risk calculated from the FRS, and doctors need to pay attention to this CVD risk in apparently healthy adults with hyperuricemia.
    Clinical Chemistry and Laboratory Medicine 02/2011; 49(5):909-14. · 2.15 Impact Factor
  • Article: A novel dipeptidyl peptidase IV inhibitor DA-1229 ameliorates streptozotocin-induced diabetes by increasing β-cell replication and neogenesis.
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    ABSTRACT: We studied the effect of a novel dipeptidyl peptidase IV (DPP IV) inhibitor, DA-1229, on blood glucose profile and pancreatic β-cell mass in established diabetes after streptozotocin (STZ) treatment. Mice that developed diabetes after administration of STZ 100mg/kg were treated with DA-1229 for 13 weeks. DA-1229 significantly reduced plasma DPP IV activity, and enhanced glucagon-like peptide 1 (GLP-1) levels. In STZ-treated mice fed DA-1229 (STZ-DA), blood glucose levels were significantly lower than those in diabetic mice fed normal chow (STZ-NC). Basal and glucose-stimulated insulin secretion and glucose tolerance assessed by intraperitoneal glucose tolerance test were significantly improved by DA-1229 administration. Volume density of β-cell was significantly increased in STZ-DA mice compared to STZ-NC mice, suggesting that DA-1229-mediated amelioration of established diabetes was due to beneficial effect of DA-1229 on β-cell mass. The number of replicating β-cells and that of scattered small β-cell unit representing β-cell neogenesis were significantly increased in STZ-DA mice compared to STZ-NC mice, explaining increased β-cell mass by DA-1229. The expression of PDX-1, a downstream mediator of GLP-1 action, was increased in islets of STZ-DA mice compared to STZ-NC mice. These results suggest a therapeutic potential of DA-1229 in diabetes, particularly that associated with decreased β-cell mass.
    Diabetes research and clinical practice 01/2011; 91(1):72-9. · 2.16 Impact Factor
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    Article: Heart rate variability and length of survival in hospice cancer patients.
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    ABSTRACT: We examined the association between heart rate variability (HRV) and survival duration to evaluate the usefulness of HRV as a prognostic factor for hospice cancer patients. In terminally ill cancer patients who visited the Hospice clinic, we checked demographic data, Karnofsky performance scale (KPS), HRV, dyspnea, anorexia, as well as fasting blood glucose and total cholesterol. After following up their duration of survival, we examined meaningful prognostic factors for predicting life expectancy through the survival analysis. A total of 68 patients were included in final analysis. As KPS was lower, or when combined with dyspnea or anorexia, the survival duration was much shorter. HRV parameters except heart rate were all impaired in most patients. In particular, the group with mean heart rate of 100 or more beats per minute and the group with standard deviations of normal-to-normal R-R intervals (SDNN) of 21.3 ms (75 percentile) or less showed significantly shorter survival duration. The final multivariate analysis adjusting for age, gender, fasting blood glucose, and total cholesterol showed that KPS, dyspnea, anorexia, and SDNN were significant prognostic factors in survival duration. For the first time, we report that SDNN is a prognostic factor in terminal cancer patients.
    Journal of Korean medical science 08/2010; 25(8):1140-5. · 0.84 Impact Factor
  • Article: Regulation of adiponectin receptor 2 expression via PPAR-alpha in NIT-1 cells.
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    ABSTRACT: Adiponectin receptors mediate the antidiabetic effects of adiponectin. Although suggested to be mainly expressed in muscle, liver, and adipocyte cells, the expression of adiponectin receptors in beta cells is unclear. Given the primary involvement of this cell type in diabetes mellitus, we presently examined the expression level of adiponectin receptor 2 (AdiR2) in beta cells. Expression was significantly increased under acute hyperlipidemic conditions but impaired under chronic conditions. The impaired AdiR2 expression may play a role in worsened beta cell function. Clofibrate, an agonist of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) delayed the palmitate-induced impairment of AdiR2 expression and PPAR-alpha; this delay was abolished by PPAR-alpha targeted small interfering RNA. The results suggest that AdiR2 expression is regulated by palmitate via PPAR-alpha.
    Endocrine Journal 05/2009; 56(3):377-82. · 2.03 Impact Factor
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    Article: Primary pulmonary Ewing's sarcoma/primitive neuroectodermal tumor in a 67-year-old man.
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    ABSTRACT: Extraskeletal Ewing's sarcoma (EES) is a branch of neuroectodermal tumor (PNET), which is very rare soft tissue sarcoma. We report a case of EES/PNET arising is the lung of a 67-yr-old man. Computed tomography, bone scintigraphy, and positron emission tomography confirmed the mass to have a primary pulmonary origin. The mass showed positive reactivity in the Periodic Acid Schiff (PAS) stain and MIC-2 immunoreactivity in immunohistochemical stain. Fluorescence in situ hybridization (FISH) was performed, which revealed an EWSR1 (Ewing sarcoma breakpoint region 1) 22q12 rearrangement. The diagnosis was confirmed both pathologically and genetically. The mass lesion was resected, and the patient is currently undergoing chemotherapy.
    Journal of Korean Medical Science 10/2007; 22 Suppl:S159-63. · 0.99 Impact Factor
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    Article: Clinical features of bronchogenic large cell carcinoma confirmed by surgical resection.
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    ABSTRACT: To define the final outcome of large cell carcinomas (LCC) after surgical treatment, the histopathology, clinical features and follow-up results of 28 cases were reviewed. Twenty eight patients, with LCC that underwent a surgical resection between 1986 and 2001, at the Severance Hospital, were retrospectively reviewed. We analyzed clinical data, radiological findings, pathologic findings, treatment modalities, and survival. The prevalence of LCC was 2.9% (29 cases) among the surgically resected primary lung cancer cases (1003 cases) during the 15 year period of the study. The mean age of the patients was 59 years old, with 25 male cases. There were 23 smokers, smoking an average of 33 pack years. A cough was the most frequent symptom. There were 15 cases located in the peripheral part of the lung and 26 consisted of a lobulated mass. From a chest CT scan, 26 cases had necrotic portions, which appeared to be low density. The postoperative stages were IA, IB, IIB, IIIA and IV in 1 (3.6%), 11 (39.3%) 8 (28.5%), 7 (25%), 1 case (3.6%), respectively. The concordance rate of the pre- and postoperative stage was 43%. The median survival time and 5 year-survival rate were 54.5 months and 45%, respectively. Our results suggested that a LCC in the lung was predominant in males, and equally located at the center and periphery of the lung in the surgically resected cases. To define the treatment outcome and risk factors of a LCC of the lung, further multicenter studies are needed.
    The Korean Journal of Internal Medicine 01/2004; 18(4):212-9.