Yoonki Hong

Kangwon National University Hospital, Shunsen, Gangwon, South Korea

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Publications (15)20.72 Total impact

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    ABSTRACT: Although many patients with severe emphysema have benefited from bronchoscopic lung volume reduction (BLVR) worldwide, experience of BLVR in Asian emphysema patients is scarce. Between July 2012 and March 2013, seven patients with advanced heterogeneous emphysema underwent BLVR in the Asan Medical Center. They had severe dyspnea and poor lung function (Modified Medical Research Council dyspnea scale 3-4; median forced expiratory volume in 1 sec [FEV1], 0.59 L [19.0 % predicted]; median 6-min walk distance [6MWD], 195 m). Endobronchial valves were inserted into the target lobe which was most hyperinflated and least perfused, and had no collateral ventilation with other lobes. Six patients showed clinical improvement after 1 month. Of them, 2 patients improved to dyspnea scale 1 and 4 patients did to scale 2 (P = 0.026). The median FEV1 increased from 0.59 to 0.89 L (51%; P = 0.028) and the median 6MWD increased from 195 to 252 m (29.2%; P = 0.028). Two patients developed a pneumothorax (one requiring drainage) and one patient experienced slight hemoptysis; however, there were no other serious adverse events. BLVR is effective in Asian advanced emphysema patients, with noted clinical improvements in lung function and exercise capacity.
    Journal of Korean medical science. 10/2014; 29(10):1404-10.
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    ABSTRACT: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation and results from environmental factors and genetic factors. Although cigarette smoking is a major risk factor, other environmental exposures can influence COPD. The purpose of this study is to investigate the clinical characteristics of COPD according to the history of environmental exposure.
    Tuberculosis and Respiratory Diseases 05/2014; 76(5):226-32.
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    ABSTRACT: Spirometric measurements of pulmonary function are important in diagnosing and determining the severity of chronic obstructive pulmonary disease (COPD). We performed this study to determine whether candidate genes identified in genome-wide association studies of spirometric measurements were associated with COPD and if they interacted with smoking intensity. The current analysis included 1,000 COPD subjects and 1,000 controls recruited from 24 hospital-based pulmonary clinics. Thirteen SNPs, chosen based on genome-wide association studies of spirometric measurements in the Korean population cohorts, were genotyped. Genetic association tests were performed, adjusting for age, sex, and smoking intensity, using models including a SNP-by-smoking interaction term. PID1 and FAM13A were significantly associated with COPD susceptibility. There were also significant interactions between SNPs in ACN9 and FAM13A and smoking pack-years, and an association of ACN9 with COPD in the lowest smoking tertile. The risk allele of FAM13A was associated with increased expression of FAM13A in the lung. We have validated associations of FAM13A and PID1 with COPD. ACN9 showed significant interaction with smoking and is a potential candidate gene for COPD. Significant associations of genetic variants of FAM13A with gene expression levels suggest that the associated loci may act as genetic regulatory elements for FAM13A gene expression.
    Beiträge zur Klinik der Tuberkulose 04/2014; · 2.06 Impact Factor
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    ABSTRACT: Background We aimed to identify the 1-year relapse rate and risk factors for patients with pulmonary tuberculosis (TB) treated with a 6-month daily regimen. Methods A total of 317 patients with pan-susceptible pulmonary TB who completed a 6-month daily course of treatment [2HRZ(E)/4HR(E)] were retrospectively analyzed. Results The mean age was 50.0±16.8 years and men were predominant (61.2%). All of 137 adults tested for HIV were negative. Six (1.9%) cases relapsed within one year. Relapse rate was higher in patients with a positive culture after 2 months of treatment (10.0%, p = 0.049) and in patients with both a positive culture after 2 months of treatment and cavitation on initial chest radiograph (18.2%, p = 0.015), whereas relapse rate in patients with cavitation alone was comparable to that of the total population (2.7%). Among various risk factors known to increase risk of relapse, the combined variable of cavitation and positive culture at 2 months (OR=15.56, 95% CI 2.56-98.71, p = 0.003) was only associated with increased relapse rate in a multivariate analysis. Conclusions Even with a 6-month daily treatment regimen throughout the intensive and continuation phases, the relapse rate was unacceptably high in patients with both a positive culture at 2 months of treatment and cavitation on baseline chest radiography. Intensification of treatment, such as an extension of treatment duration, should be considered in this category of patients.
    Respiratory medicine 01/2014; · 2.33 Impact Factor
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    ABSTRACT: Introduction The development of reliable gene expression profiling technology increasingly impacts our understanding of lung cancer biology. Here, we used RNA sequencing (RNA-Seq) to compare the transcriptomes of non-small cell lung cancer (NSCLC) and normal lung tissues and to investigate expression in lung cancer tissues. Methods We enrolled 88 male patients (mean age, 61.2 years) with NSCLC. RNA-Seq was performed on 88 pairs of NSCLC tumor tissue and non-tumor tissue from 54 patients with adenocarcinoma and 34 patients with squamous cell carcinoma. Immunohistochemistry was performed to validate differential candidate gene expression in a different NSCLC group. Results RNA-Seq produced 25.41 × 106 (± 8.90 × 106) reads in NSCLC tissues and 24.70 × 106 (± 4.70 × 106) reads in normal lung tissues [mean (± standard deviation)]. Among the genes expressed in both tissues, 335 were upregulated and 728 were downregulated ≥ 2-fold (P < 0.001). Four upregulated genes–CBX3, GJB2, CRABP2, and DSP–not previously reported in lung cancer were studied further. Their altered expression was verified by immunohistochemistry in a different set of NSCLC tissues (n = 154). CBX3 was positive in 90.3% (139 cases) of the samples; GJB2, in 22.7% (35 cases); CRABP2, in 72.1% (111 cases); and DSP, in 17.5% (27 cases). The positive rate of CRABP2 was higher in adenocarcinoma than squamous cell carcinoma (p < 0.01). Conclusions CBX3 and CRABP2 expression was markedly increased in lung cancer tissues and especially CRABP2 may be promising candidate genes in lung adenocarcinoma.
    Lung cancer (Amsterdam, Netherlands) 01/2014; · 3.14 Impact Factor
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    ABSTRACT: We aimed to investigate the results of anti-tumor necrosis factor (TNF) therapy in patients with a previous history of tuberculosis (TB). A total of 101 patients with a previous history of TB receiving TNF antagonists between December 2004 and September 2012 at the Asan Medical Center in South Korea were retrospectively analyzed. The mean age of the 101 subjects was 40.4 ± 16.0 years and 51 patients (50.5%) were male. The underlying immune-mediated inflammatory diseases (IMIDs) were Crohn's disease in 55 (54.5%), rheumatoid arthritis in 27 (26.7%), and ankylosing spondylitis in 13 (12.9%) patients. Chest radiography findings were suggestive of previous TB lesions in 33 (32.7%) patients. The rates of positivity in the tuberculin skin test and interferon-gamma release assay were 21.8% (22/101) and 44.6% (45/101), respectively. Latent TB infection (LTBI) treatment was initiated in 11 subjects (10.9%) based on previous inappropriate anti-TB treatments (n = 10) or recent TB contact history (n = 1), irrespective of the LTBI test results. The median follow-up duration after the initiation of TNF antagonist therapy was 31.5 months. Active TB developed, six years after the initiation of TNF antagonist, in one patient (1.0%) who had not received LTBI treatment. The incidence rate of TB was calculated at 336 per 100,000 person-year (PY). Patients with IMIDs who have a previous history of TB can be treated with TNF antagonists with an acceptable incidence of TB, if LTBI treatment is performed based on clinical judgments including the adequacy of previous anti-TB treatment and recent contact history.
    Respiratory medicine 08/2013; · 2.33 Impact Factor
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    ABSTRACT: Extracorporeal membrane oxygenation (ECMO) is useful for providing hypoxic patients with ventilatory support, but its usefulness in the management of patients with central airway obstruction has rarely been reported. Nineteen cases in one center where venovenous (VV) ECMO was used to support patients with severe central airway obstruction while they underwent lifesaving interventions are reported here. In total, 113 cases of VV ECMO were performed in Asan Medical Center between January 2009 and June 2012. In 19 cases (18 patients), VV ECMO was used to support patients with severe airway obstruction. Of the 18 patients, 13 were male, and their median age was 62.5 (range, 16-82) years. The main reasons for using ECMO to provide airway security were malignant mass removal with a rigid bronchoscope (8 cases) and insertion of a tracheal stent (7 cases). The median ECMO time was 20.9 (range, 2.2-113.4) hours. In 1 case, a patient died of massive bleeding after a malignant mass was removed. Weaning off ECMO therapy occurred successfully in the remaining 18 cases. Venovenous ECMO may be useful in patients with central airway obstruction because it provides short-term airway security while lifesaving procedures are being performed.
    Journal of critical care 07/2013; · 2.13 Impact Factor
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    ABSTRACT: We investigated the prevalence of latent tuberculosis infection (LTBI) among the health care workers (HCWs) and analyzed its risk factors in South Korea. A standard questionnaire regarding the baseline demographics and risk factors for LTBI was given to each participant and tuberculin skin test (TST), QuantiFERON-TB GOLD In-Tube (QFT-GIT) assay, and chest radiography were performed. A total of 493 participants, 152 (30.8%) doctors and 341 (69.2%) nurses were enrolled in eight tertiary referral hospitals. The mean age of the subjects was 30.6 years old, and 383 (77.7%) were female. Of the 152 doctors, 63 (41.4%) and 36 (23.7%) were positive by TST and by QTF-GIT, respectively, and among the 341 nurses, 119 (34.9%) and 49 (14.4%) had positive TST and QFT-GIT results, respectively. Overall, the agreement between the two tests was 0.22 by the chance corrected proportional agreement rate (kappa coefficient) in 493 subjects. Experience of working in tuberculosis (TB)-related departments was significantly associated with positive LTBI test results by QFT-GIT assay, not by TST. In multivariate analysis, only age was independently associated with increased risk of a positive TST result, while age and experience of working in TB-related departments (odds ratio, 2.29; 95% confidence interval, 1.01-5.12) were independently associated with increased risk of a positive QFT-GIT result. A high prevalence of LTBI was found among South Korean HCWs. Considering the association between the experience of working in TB-related departments and high risk of LTBI, QFT-GIT may be a better diagnostic test for LTBI than TST in HCWs.
    Tuberculosis and Respiratory Diseases 07/2013; 75(1):18-24.
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    ABSTRACT: OBJECTIVE: We investigated the efficacy of rifabutin (RFB)-containing regimens for the treatment of RFB-susceptible, multidrug-resistant tuberculosis (MDR-TB). METHODS: From 146 patients diagnosed with MDR-TB between January 2006 and December 2009 at Asan Medical Center in South Korea, 31 patients (21.2%) were found to have RFB-susceptible MDR-TB. Of these 31 patients, 14 patients who had been treated with RFB for more than one month were included. Forty-two patients with RFB-resistant MDR-TB were selected as a control group, and the outcomes of both groups were retrospectively compared. RESULTS: Of 14 patients with RFB-susceptible MDR-TB, the mean age was 44.4 years and the proportion of extensively drug-resistant TB (XDR-TB) was 35.7% (5/14). Baseline characteristics and the drug resistance pattern (except RFB) did not differ between the two groups. Treatment success was achieved in 12 (85.7%) patients in the RFB group: cure in 10 (71.4%) and treatment completion in two (14.3%). The treatment success rate was 52.4% (22/42) in the control group (p = 0.032). Treatment failure was more common in patients of the control group (40.5% vs. 14.3%; p = 0.106). CONCLUSIONS: RFB is useful as an additional drug in the treatment of MDR-TB in patients with RFB-susceptible MDR-TB.
    Respiratory medicine 11/2012; · 2.33 Impact Factor
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    ABSTRACT: To date, clinico-physiologic indices have not been compared with quantitative CT imaging indices in determining the risk of chronic obstructive pulmonary disease (COPD) exacerbation. We therefore compared clinico-physiologic and CT imaging indices as risk factors for COPD exacerbation in patients with COPD. We retrospectively analyzed 260 COPD patients from pulmonary clinics at 11 hospitals in Korea from June 2005 to November 2009 and followed-up for at least one year. At the time of enrollment, none of these patients had COPD exacerbations for at least 2 months. All underwent clinico-physiologic and radiological evaluation for risk factors of COPD exacerbation. After 1 yr, 106 of the 260 patients had at least one exacerbation of COPD. Multiple logistic regression analysis showed that old age, high Charlson Index, and low FEV(1) were significant in a clinico-physiologic model, with C-statistics of 0.69, and that increased age and emphysema index were significant in a radiologic model, with C-statistics of 0.64. The difference between the two models was statistically significant (P = 0.04 by bootstrap analysis). Combinations of clinico-physiologic risk factors may be better than those of imaging risk factors in predicting COPD exacerbation.
    Journal of Korean medical science 12/2011; 26(12):1606-12. · 0.84 Impact Factor
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    ABSTRACT: The clinical significance of serum CA-125 measurements in patients with non-tuberculous mycobacterial (NTM) lung disease has not been investigated. This study showed that serum CA-125 levels were elevated in some patients with NTM pulmonary disease. Further studies are needed to investigate the usefulness of serum CA-125 measurements in patients with NTM pulmonary disease. Although cancer antigen 125 (CA-125) is a useful marker for the diagnosis of ovarian cancer, CA-125 levels are elevated in many benign conditions, including tuberculosis (TB). The clinical significance of serum CA-125 measurements in patients with non-tuberculous mycobacterial (NTM) lung disease was evaluated. Patients with NTM lung disease (n=53), in whom serum CA-125 levels had been measured, were retrospectively enrolled in the study. Twenty-eight patients with pulmonary TB were included as a comparison group. Clinical, radiological and bacteriological parameters were assessed according to serum CA-125 status. Among 53 patients with NTM lung disease, serum CA-125 levels were elevated in 28 (52.8%), and this proportion was not significantly different from that of the TB patients (44.8%). Cavitation and upper lobe cavitary type disease were more frequent in NTM patients with elevated serum CA-125 levels compared with those without increased CA-125 levels (P<0.05 for both). The clinical course of NTM lung disease was correlated with changes in serum CA-125 levels. Serum CA-125 levels were increased in significant proportions of NTM patients, as well as TB patients. Further studies are needed to investigate the usefulness of serum CA-125 measurements in patients with NTM pulmonary disease.
    Respirology 02/2010; 15(2):357-60. · 2.78 Impact Factor
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    ABSTRACT: A new interpretative strategy for pulmonary function tests (PFT) has been proposed by the American Thoracic Society/European Respiratory Society (ATS/ERS) Task Force. To assess the accuracy of this strategy, clinical diagnosis was compared with the PFT interpretation in patients showing concomitant decreases in FEV(1) and FVC. A retrospective study was conducted of 681 patients with normal FEV(1)/FVC and low FVC who underwent lung volume measurements and spirometry on the same date between July and November 2005 at Asan Medical Center, Seoul, Korea. Patients were clinically diagnosed by the consensus decision of two respiratory physicians, and the kappa coefficient was calculated to compare the clinical diagnosis with the PFT interpretation using the ATS/ERS strategy. The PFT interpretation showed an obstructive pattern in 205 patients and a restrictive pattern in 476. Of the 205 patients with an obstructive pattern on PFT, 44 were clinically diagnosed with obstructive, 97 with restrictive and 17 with mixed disease, whereas 47 patients had no disease. Of the 476 patients with a restrictive pattern on PFT, 11 were clinically diagnosed with obstructive, 369 with restrictive and 60 with mixed disease, whereas 36 patients had no disease. The kappa coefficient was 0.35 (95% confidence interval: 0.26-0.44; P < 0.0001). The weak agreement between the clinical diagnosis and the PFT interpretation in patients showing concomitant decreases in FEV(1) and FVC suggests that other clinical findings should be assessed in addition to PFT.
    Respirology 07/2008; 13(4):569-74. · 2.78 Impact Factor
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    ABSTRACT: Results: Agreement between clinical assessment and interpretation of DL CO was 22% for the use of Burrows' equation and 78% for the use of Park's equation. The sensitivity and specificity of the Burrows' equation for diagnosing ILD were 64.2% and 100%. The sensitivity and specificity of the Park's equation for diagnosing ILD were 90.1% and 100%. The sensitivity of the Park's equation for diagnosing ILD was significantly higher than that of Burrows' equation (p
    Tuberculosis and Respiratory Diseases 01/2008; 64(2).
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    Tuberculosis and Respiratory Diseases 01/2007; 63(5).
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    ABSTRACT: Chronic obstructive pulmonary disease (COPD) is a spectrum of various syndromes that share airflow limitation but differ in many respects. Although airflow limitation is a defining element of COPD, forced expiratory volume in 1 s (FEV1) alone is not sufficient to explain the heterogeneity of COPD. Phenotypic characterization of clinically relevant subgroups of COPD will increase our understanding of COPD. Furthermore, a greater understanding of the complex interrelationships between the phenotypes and their environmental, genetic, molecular, and cellular basis may be achieved with comprehensive and integrated method (systems biology and network medicine). Incorporation of information obtained from these analyses into our clinical practice would allow clinicians to treat individual patients with so-called Personalized, Predictive, Preventive, and Participatory (P4) medicine. By understanding COPD heterogeneity, it may be possible in the future to detect the disease earlier and to target treatment to reduce mortality and modify the course of the disease.
    Current Respiratory Care Reports. 1(3).

Publication Stats

13 Citations
20.72 Total Impact Points

Institutions

  • 2013–2014
    • Kangwon National University Hospital
      Shunsen, Gangwon, South Korea
    • Kangwon National University
      • Department of Internal Medicine
      Shunsen, Gangwon, South Korea
  • 2010–2013
    • Asan Medical Center
      • Department of Pulmonary and Critical Care Medicine
      Seoul, Seoul, South Korea
  • 2008–2013
    • Ulsan University Hospital
      Urusan, Ulsan, South Korea