Young Sik Park

Seoul National University, Sŏul, Seoul, South Korea

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Publications (41)60.36 Total impact

  • Ha Youn Lee, Joohae Kim, Yong Suk Jo, Young Sik Park
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    ABSTRACT: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a safe and effective diagnostic tool for mediastinal evaluation. The guidelines for mediastinal evaluation of lung cancer were recently revised for both endoscopic procedures and surgical medical staging, and EBUS-TBNA is expected to be used more often in lung cancer diagnosis and staging. The major complication rate reported in previous meta-analyses is very low at 0.07-.15%; however, the mortality rate has not been reported. We present 2 cases of acute bacterial pericarditis after EBUS-TBNA, with 1 case resulting in mortality, and we discuss the appropriate management. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 12/2014; · 2.40 Impact Factor
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    ABSTRACT: Multiple comorbidities related to chronic obstructive pulmonary disease (COPD) have been reported and make it a difficult disease to treat.•We analyzed the relationship between comorbidities and COPD.•Only hypertension and a history of pulmonary tuberculosis were independently associated with COPD after adjustment for confounders.•The results of our study suggest that majority of COPD patients might have similar risk factors with its comorbidities.
    Respiratory Medicine. 11/2014;
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    ABSTRACT: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease of unknown causes. Three proteins (mammalian target of rapamycin, mTOR; zinc finger E-box-binding homeobox 1, ZEB1; Rho-associated, coiled-coil containing protein kinase 1, ROCK1) may be related to pulmonary fibrosis. However, they have not been assessed in human pulmonary fibrosis. We assessed the clinical significance of mTOR, ZEB1, and ROCK1 expression in human pulmonary fibrosis of usual interstitial pneumonia (UIP) pattern.
    BMC Pulmonary Medicine 10/2014; 14(1):168. · 2.76 Impact Factor
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    ABSTRACT: Background:No study has determined whether the risk of mortality predicted by the gender, age, and physiological variables (GAP) model matches the observed mortality from idiopathic pulmonary fibrosis (IPF) in non-Western populations. We evaluated the clinical course of IPF and validated the GAP model in Korean IPF patients. Methods:We included 268 patients who had been diagnosed with IPF at Seoul National University Hospital between 2005 and 2009. For each patient, demographics and clinical data such as lung physiological parameters at the diagnosis of IPF were evaluated. And, we validated the GAP model using discrimination and calibration to predict the risk of death in Korean IPF patients. Results:The study population comprised 181 men and 87 women, with a mean age of 65.9 years. The mean baseline percent predicted functional vital capacity (FVC) was 77 and percent predicted carbon monoxide diffusing capacity (DLCO) was 65.9. 157 (58.6%) deaths occurred during the follow-up, and the median time to death was 4.64 years. The observed cumulative mortality rates at 1, 2, and 3 years were 10.4%, 20.9%, and 31.0%, respectively. The GAP model produced estimates of 1-year mortality risk consistent with the observed data (c-statistic: GAP calculator 0.74 and GAP index and staging system 0.72, P < 0.29). However, calibration of the GAP model at 3 years was not satisfactory. Conclusion:The GAP model showed similar discrimination power compared with the original cohort. But it did not predict the 3-year risk of death accurately. Further multinational validation study will be needed.
    Chest 09/2014; · 7.13 Impact Factor
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    Young Sik Park
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    ABSTRACT: The US National Lung Screening Trial (NLST) demonstrated a 20% reduction in lung cancer mortality and a 6.7% decrease in all-cause mortality. The NLST is the only trial showing positive results in a high-risk population, such as in patients with old age and heavy ever smokers. Lung cancer screening using a low-dose chest computed tomography might be beneficial for the high-risk group. However, there may also be potential adverse outcomes in terms of over diagnosis, bias and cost-effectiveness. Until now, lung cancer screening remains controversial. In this review, we wish to discuss the evolution of lung cancer screening and summarize existing evidences and recommendations.
    Tuberculosis and Respiratory Diseases 08/2014; 77(2):55-9.
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    ABSTRACT: Background and objectiveThere is limited data on size change during natural progression of pulmonary aspergilloma. We aimed at elucidating the clinical course and prognosis of aspergilloma according to its size change.MethodsA multicentre retrospective observational study was performed in 143 adult pulmonary aspergilloma patients with serial chest computed tomography images. The clinical course and risk of haemoptysis according to the size change of the cavity or mass of aspergillomas was evaluated.ResultsMedian follow-up duration was 5.1 years. The size of aspergillomas changed in 39.2% of study subjects. Decreased and increased volumes of aspergilloma were observed in 13.3% and 25.9%, respectively. Patients with decreased volume had significantly higher C-reactive protein, and more severe bronchiectasis and tuberculosis-destroyed lung. Clinically significant haemoptysis occurred in 50.3% of patients and was significantly associated with the cavity and mass volume of aspergilloma, but not the extent of volume change. A mean cavity diameter of more than 22 mm and a mass diameter of more than 18 mm increased the risk of clinically significant haemoptysis.ConclusionsA significant portion of pulmonary aspergilloma changed size in our population. The prevalence of clinically significant haemoptysis was associated with absolute size of cavity and mass of aspergilloma.
    Respirology 08/2014; · 2.78 Impact Factor
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    ABSTRACT: IntroductionThe solitary pulmonary nodule (SPN) is a common clinical problem usually detected incidentally during screening tests for lung cancer. Video-assisted thoracoscopic surgery (VATS) is performed for diagnosing SPNs when there are technical difficulties with transthoracic needle aspiration biopsy or bronchoscopic biopsy, inconclusive biopsy results, or when there is a high suspicion of malignancy.Objectives This study aimed to identify factors that can reduce unnecessary VATS for the diagnosis of SPNs.Methods We retrospectively analyzed patients with SPNs (n = 107) who had undergone diagnostic VATS at Seoul National University Hospital from January 2007 to December 2008. Clinical and radiological parameters were evaluated to compare benign and malignant SPNs.ResultsBenign SPNs were diagnosed in 31 patients (29.0%). The most common reason for patients to undergo a diagnostic VATS was a previous history of previous malignancy. The most common histological findings in patients with benign SPNs were nonspecific inflammatory lesions (29.0%) and tuberculosis (TB) (16.1%). The presence of respiratory symptoms was significantly associated with benign diseases (p = 0.004, odds ratio [OR] 0.189, 95% confidence interval [CI] 0.060-0.590), and part-solid nodules were significantly related to malignancy (p = 0.026, OR 6.34, 95% CI 1.248-32.169).Conclusion Approximately 30% of SPNs resected by VATS were benign. Although we did not identify a definite factor for predicting benign disease or malignancy, the presence of respiratory symptoms was related to benign disease and the presence of part-solid nodules was associated with malignancy.
    The Clinical Respiratory Journal 08/2014; · 1.66 Impact Factor
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    ABSTRACT: Objectives The incidence of Pneumocystis jirovecii pneumonia (PCP) in patients without HIV infection (non-HIV PCP) has been increasing along with the increased use of chemotherapeutic agents and immunosuppressants, but the prognostic factors of non-HIV PCP remain unclear. This study aimed to identify the prognostic factors of non-HIV PCP Methods Immunocompromised patients without HIV infection who were diagnosed and treated for PCP were included. The PCP diagnosis was based on positive direct fluorescent antibody (DFA) or polymerase chain reaction (PCR) results and compatible clinical symptoms and radiological findings. Results In total, 372 non-HIV patients with positive PCP DFA or PCR findings were screened and 173 were included. Univariate analysis indicated that age, smoking, chronic lung disease or hematologic malignancy, chemotherapeutic agents, high alveolar-arterial oxygen gradient (D[A-a]O2), C-reactive protein, albumin, blood urea nitrogen (BUN), CMV antigenemia, combined bacteremia, high percentage of neutrophils and rate of co-infection in BAL fluid, and mechanical ventilator care were related to the prognosis of non-HIV PCP. Multivariate analysis revealed that high D(A-a)O2, combined bacteremia, increased BUN and preexisting lung disease were indicators of a poor prognosis. Conclusions High D(A-a)O2, combined bacteremia, increased BUN and preexisting lung disease were independent factors of poor prognosis in non-HIV PCP patients.
    The Journal of infection 07/2014; · 4.13 Impact Factor
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    ABSTRACT: Binaural hearing aids consist of two hearing devices, one for each ear. A new concept of binaural hearing aids is proposed, in which only the master hearing aid contains a Bluetooth chip for receiving stereo audio signals from an external device, and the signal in one channel is sent to the slave hearing aid from the master by a 2.4-GHz Gaussian frequency-shift keying (GFSK) RF transmission method to create the binaural hearing effect. However, a problem arises in regard to the processing necessary for the signal transmission and reception in the two hearing aids, which creates a time delay that causes the precedence effect. Therefore, an audio delay processing algorithm has been designed in the master hearing aid to synchronize with the sound output of the slave hearing aid. Experimental results show that the time difference between the two hearing aids is about 8 µs, which is effective for avoiding the precedence effect. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
    IEEJ Transactions on Electrical and Electronic Engineering 06/2014; · 0.34 Impact Factor
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    ABSTRACT: The impact of chronic obstructive pulmonary disease (COPD) on the mortality of patients with lung cancer has not been studied extensively. The objective of this study is to compare the mortality and clinical characteristics of patients with non-small-cell lung cancer (NSCLC) according to the presence of COPD. The medical records of 221 smokers diagnosed with NSCLC were reviewed. Eligible patients were dichotomized into the COPD group (n = 111) and the non-COPD group (n = 110). The overall survival and clinical characteristics were compared, and predictors of worse survival were analyzed using Cox proportional hazards regression. COPD was present in 50.2% of all patients with NSCLC, and most of the patients (92.8%) with COPD were unaware of the disease before the diagnosis of lung cancer. Patients in the COPD group were older and had a lower body mass index, higher pack-years smoking history, higher frequency of dyspnea, and higher incidence of previous malignancy. The overall survival of enrolled patients and propensity score-matched subjects was comparable between the two groups (log-rank test, p = 0.2 and 0.396, respectively). Old age, low body mass index, advanced disease stage (stages III and IV), non-squamous histology, Eastern Cooperative Oncology Group performance status of greater than or equal to 2, weight loss, and coexistence of interstitial lung disease were independent risk factors for shorter survival. COPD frequently and subliminally coexists with NSCLC. Although differences in clinical characteristic did exist, there was no impact of COPD on the mortality of patients with NSCLC with a positive smoking history in this study.
    Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 05/2014; · 4.55 Impact Factor
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    ABSTRACT: Pulmonary artery tumor embolism (PATE) is a rare disease without an established diagnostic method. In an autopsy series, however, the incidence of PATE was relatively high, between 3% and 26% in patients with a solid tumor. Here we report a case of a patient with a massive PATE from hepatocellular carcinoma diagnosed safely and promptly by endobronchial ultrasound-guided transbronchial needle aspiration.
    Thoracic Cancer. 03/2014; 5(2).
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    ABSTRACT: Background: Patients with interstitial lung disease (ILD) have a high incidence of postoperative pulmonary complications (PPCs) after lung resection, but there is little data about these complications in ILD after other types of surgery. Objectives: The aim of this study was to examine the characteristics and predictors of PPCs after major surgery in patients with ILD. Methods: We included 336 patients with ILD who underwent major surgery between January 2005 and December 2010 at two tertiary hospitals in Korea. All types of surgery that had been performed under general anesthesia were included. Demographic characteristics, preoperative lung function, and operative conditions including anesthesia time and estimated blood loss were compared between patients with and without PPCs. Results: PPCs occurred in 37 patients (11%). Thirteen patients developed pneumonia, the most common PPC, and 11 had acute exacerbation of ILD. In multivariable analysis, BMI <23 (OR = 2.488, 95% CI: 1.084-5.710, p = 0.031), emergency surgery (OR = 23.992, 95% CI: 2.629-218.949, p = 0.005), lung surgery (OR = 5.090, 95% CI: 1.391-18.628, p = 0.014), and longer anesthesia time (OR = 1.595, 95% CI: 1.143-2.227, p = 0.006) were statistically significant risk factors. Conclusions: The incidence of PPCs detected over all surgeries was not as high as that reported for lung surgery alone in ILD patients. Lower BMI, emergency surgery, lung surgery, and longer anesthesia time were risk factors. Operative conditions as well as lung function should be considered in preoperative planning and management for ILD patients undergoing major surgery. © 2014 S. Karger AG, Basel.
    Respiration 02/2014; · 2.92 Impact Factor
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    ABSTRACT: Blood lactate levels and central venous oxygen saturation (ScvO2) are known to be useful indicators of global tissue hypoxia. However, it is unclear whether ScvO2 correlates with lactate levels when measured simultaneously and whether changes in ScvO2 or lactate levels in serial measurements have prognostic value. We investigated the correlation between ScvO2 and lactate levels measured simultaneously and their association with clinical outcomes. We performed a prospective observational study of patients with severe systemic inflammatory response syndrome (SIRS) and severe sepsis who were admitted to the medical intensive care unit. ScvO2 and lactate levels were measured simultaneously at the time of study enrollment, every 6 h for 24 h, and then every 24 h until the goal was reached. Twenty-five patients were enrolled in the study; 13 have died and 12 have survived. There was no correlation between lactate levels and ScvO2. Neither lactate levels nor ScvO2 at the time of admission differed between nonsurvivors and survivors. Normalization of lactate levels within 48 h was significantly associated with survival. In patients with severe SIRS and severe sepsis, simultaneously measured ScvO2 and lactate levels showed no correlation, and normalization of lactate levels within 48 h was a predictive factor for survival.
    Beiträge zur Klinik der Tuberkulose 02/2014; · 2.06 Impact Factor
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    ABSTRACT: Although combined pulmonary fibrosis and emphysema (CPFE) might be relevant to lung cancer, no comparison studies have been done. We evaluated the risk of lung cancer among CPFE patients compared to IPF and emphysema patients. We retrospectively reviewed the medical records of patients who were diagnosed as CPFE, IPF and emphysema using chest CT scans at Seoul National University Hospital from Jan 2000 to Dec 2011. Patients with CPFE were enrolled and matched (1:1:2) with IPF and emphysema patients based on the radiological criteria. The main outcome was time to diagnosis of lung cancer and evaluated with Cox-proportional hazard regression. Forty-eight CPFE, 48 IPF, and 96 emphysema patients were included in this study. Twenty-five cases of lung cancer occurred. The CPFE group had a higher risk of lung cancer (adjusted HR 4.62, 95% CI 1.58-13.55) than that of the emphysema group. Also, IPF group had a higher risk of lung cancer (adjusted HR 4.15, 95% CI 1.03-16.78) than that of emphysema group. However, there was no statistically significant difference in lung cancer risk between the CPFE and IPF group. Additionally, the CPFE group had a higher risk of lung cancer or death (adjusted HR 4.62, 95% CI 2.25-9.47) than that of the emphysema group. In conclusion, patients with CPFE and IPF had a higher risk of lung cancer than those with emphysema, although lung cancer risk was similar between CPFE and IPF.
    Respiratory medicine 01/2014; · 2.33 Impact Factor
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    ABSTRACT: There have been few studies of pulmonary actinomycosis, which is an uncommon anaerobic infection. Consequently, the optimal therapeutic regimen, appropriate duration of treatment, long-term prognosis, and factors predicting prognosis are not well established. We retrospectively reviewed the medical records of histopathologically confirmed cases of pulmonary actinomycosis seen between November 2003 and December 2012. The study included 68 patients with a mean age of 58.4 +/- 11.6 years. Of the 68, initial surgery was performed in 15 patients (22.1%), while the remaining 53 (77.9%) received antibiotic therapy initially. In the initial antibiotic group, 45/53 (84.9%) were cured without relapse (median antibiotic duration 5.3 months). 5/53 (9.4%) patients were refractory medically (median antibiotic duration 9.7 months), and 3/53 (5.7%) experienced a recurrence (median time to relapse 35.3 months). In the initial surgery group, 14/15 (93.3%) were cured and treatment failure occurred in one (6.7%). In the multivariate analysis, the absence of an antibiotic response at 1 month was the only independent factor associated with a poor treatment outcome, with an adjusted odds ratio of 49.2 (95% CI, 3.34-724.30). There was no significant difference in treatment outcome based on the size of the parenchymal lesion, comorbidities, whether intravenous antibiotics were used, antibiotic therapy duration, or whether the initial treatment was surgical. Antibiotic treatment with or without surgery was effective for treatment of pulmonary actinomycosis. Nevertheless, treatment failure or recurrence occurred in a considerable proportion of patients, especially those resistant to the initial antibiotic treatment.
    BMC Infectious Diseases 01/2014; 14(1):10. · 3.03 Impact Factor
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    ABSTRACT: The culture-negative conversion rate of sputum after 2 months of treatment in patients with pulmonary tuberculosis (TB) is used as a reliable surrogate marker for relapse after completion of treatment. We hypothesized that culture conversion of sputum at 2 months of anti-TB treatment and the time to culture conversion are different among pulmonary TB patients who are diagnosed using different methods.
    PLoS ONE 01/2014; 9(8):e103768. · 3.53 Impact Factor
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    ABSTRACT: Background Cigarette smoking is one of the major causes of lung cancer. However, the correlation between smoking status and the survival of patients with lung cancer is uncertain. The present study aimed to evaluate the impact of smoking status on the mortality of patients with non-small cell lung cancer (NSCLC). Methods The medical records of 313 patients newly diagnosed with NSCLC between January 2005 and January 2006 were reviewed. Eligible patients were divided into ever-smokers (221 patients) and never-smokers (92 patients), and the overall survival and clinical characteristics of the two groups were compared. Predictors of survival were analyzed using Cox's proportional hazards regression. ResultsIn ever-smokers, the mean age was higher, and male gender and squamous histology were predominant compared to never-smokers. The median survival time was longer in never-smokers (21.1 vs. 41.9 months, ever-smokers vs. never-smokers, respectively; P = 0.027). Overall survival estimates at 12, 24, and 60 months were 62.9 versus 82.6%, 43.4 versus 65.2%, and 31.2 versus 42.4%, in each group. Advanced age, advanced disease stage (stages III and IV), and coexistence of interstitial lung disease were analyzed as independent risk factors for shorter survival. Although ever-smoking was not an independent risk factor, current smoking was a risk factor for higher mortality. Conclusions The overall mortality of ever-smokers was higher than that of never-smokers in patients with newly diagnosed NSCLC, and current smoking was an independent risk factor for a poorer prognosis.
    Thoracic Cancer. 01/2014; 5(1).
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    ABSTRACT: A decrease of bone mass is a major risk factor for fracture. Several natural products have traditionally been used as herbal medicines to prevent and/or treat bone disorders including osteoporosis. Praeruptorin A is isolated from the dry root extract of Peucedanum praeruptorum Dunn and has several biological activities, but its anti-osteoporotic activity has not been studied yet. The effect of praeruptorin A on the differentiation of bone marrow-derived macrophages into osteoclasts was examined by phenotype assay and confirmed by real-time PCR and immunoblotting. The involvement of NFATc1 in the anti-osteoclastogenic action of praeruptorin A was evaluated by its lentiviral ectopic expression. Intracellular Ca(2+) levels were also measured. Praeruptorin A inhibited the RANKL-stimulated osteoclast differentiation accompanied by inhibition of p38 and Akt signaling, which could be the reason for praeruptorin A-downregulated expression levels of c-Fos and NFATc1, transcription factors that regulate osteoclast-specific genes, as well as osteoclast fusion-related molecules. The anti-osteoclastogenic effect of praeruptorin A was rescued by overexpression of NFATc1. Praeruptorin A strongly prevented the RANKL-induced Ca(2+) oscillation without any changes in the phosphorylation of PLCγ. Praeruptorin A could exhibit its anti-osteoclastogenic activity by inhibiting p38/Akt-c-Fos-NFATc1 signaling and PLCγ-independent Ca(2+) oscillation.
    PLoS ONE 01/2014; 9(2):e88974. · 3.53 Impact Factor
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    ABSTRACT: Endobronchial metastasis of leiomyosarcoma is rare, but it can cause life-threatening complications, such as massive hemoptysis, respiratory failure or even death. The development of new endoscopic modalities allows for effective endobronchial management. We report three patients with endobronchial metastases from advanced leiomyosarcomas which caused bronchial obstruction. The bronchoscopic examinations revealed masses obstructing the left main bronchus in all three patients. After removing the endobronchial tumor via interventional bronchoscopy, there was symptomatic and radiologic improvement. Moreover, the patients were able to undergo additional palliative chemotherapy. Therefore, endobronchial management of endobronchial tumors should be considered in the treatment of endobronchial metastasis, even in patients with advanced malignancies.
    Tuberculosis and Respiratory Diseases 12/2013; 75(6):250-5.
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    ABSTRACT: Dirofilariasis is a rare disease in humans. We report here a case of a 48-year-old male who was diagnosed with pulmonary dirofilariasis in Korea. On chest radiographs, a coin lesion of 1 cm in diameter was shown. Although it looked like a benign inflammatory nodule, malignancy could not be excluded. So, the nodule was resected by video-assisted thoracic surgery. Pathologically, chronic granulomatous inflammation composed of coagulation necrosis with rim of fibrous tissues and granulations was seen. In the center of the necrotic nodules, a degenerating parasitic organism was found. The parasite had prominent internal cuticular ridges and thick cuticle, a well-developed muscle layer, an intestinal tube, and uterine tubules. The parasite was diagnosed as an immature female worm of Dirofilaria immitis. This is the second reported case of human pulmonary dirofilariasis in Korea.
    The Korean Journal of Parasitology 10/2013; 51(5):569-72. · 0.88 Impact Factor

Publication Stats

19 Citations
60.36 Total Impact Points

Institutions

  • 2014
    • Seoul National University
      Sŏul, Seoul, South Korea
    • Kyungpook National University
      Daikyū, Daegu, South Korea
  • 2009–2014
    • Seoul National University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 2012
    • Dongguk University
      Sŏul, Seoul, South Korea