Sung Ho Hwang

Ajou University, Sŏul, Seoul, South Korea

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Publications (57)84.93 Total impact

  • Air Quality Atmosphere & Health 01/2015; DOI:10.1007/s11869-015-0316-9 · 1.46 Impact Factor
  • Tae Won Park, Sung Ho Hwang, Kyoung-Mu Lee
    10/2014; 40(5):385-396. DOI:10.5668/JEHS.2014.40.5.385
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    Sung Ho Hwang, Jae Kyoung Ahn, Jae Bum Park
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    ABSTRACT: Objectives: We measured the concentrations of culturable airborne fungi (CAF) in enclosed environments at 16 underground subway stations of the Seoul Metro in 2013, and investigated the effect of environmental factors, including temperature, relative humidity, the number of passengers, and distance from the platform. Methods: The cultured fungi were identified by the lactophenol cotton blue (LPCB) staining method and were classified by observing the form, shape, and color of colony. A nonparametric analysis was used to determine if the differences in the concentrations of CAF were statistically significant. Results: The concentrations of CAF at the stations were the highest in station p () with arange between 3 and . There was a significant correlation between CAF concentration and the distance from platform (r = 0.544, p < 0.01). Geotrichum spp. and Penicillium spp. were the predominant species. Conclusion: It is recommended that special attention be given during rush hour, which is in the morning (08:00-10:00) and in the early evening (18:00-19:00) to improve the indoor air quality of the subway stations.
    04/2014; 40(2). DOI:10.5668/JEHS.2014.40.2.81
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    Sung Ho Hwang, Chung Sik Yoon, Jae Bum Park
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    ABSTRACT: To evaluate the monthly variation in the airborne (1→3)-β-D-glucan level throughout one year and its relationship with climatic factors (temperature, relative humidity, wind speed, hours of daylight, cloud cover, and pollen counts). A total of 106 samples were collected using a two-stage cyclone sampler at five outdoor sampling locations (on top of 5 university buildings). The kinetic limulus amebocyte lysate assay was used to obtain (1→3)-β-D-glucan levels. Airborne (1→3)-β-D-glucan levels were significantly higher in the spring, particularly in April, and temperature was significantly related to (1→3)-β-D-glucan levels (r =0.339, p<0.05). (1→3)-β-D-glucan levels may be highest in the spring, and outdoor temperature may influence (1→3)-β-D-glucan levels.
    03/2014; 47(2):124-8. DOI:10.3961/jpmph.2014.47.2.124
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    Sung Ho Hwang, Hyun Hee Park, Chung Sik Yoon
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    ABSTRACT: Background The purpose of this study was to compare the concentration of total airborne bacteria (TAB) in biosafety cabinets (BSCs) at universities and hospital microbial laboratories to assess the performance of BSCs. Methods TAB was determined by using the single-stage Anderson sampler (BioStage Viable Cascade Impactor). The samples were obtained three times (with the BSC turned off and the shield open; with the BSC turned off and the shield closed; and with the BSC tuned on and operating) from the areas in front of 11 BSCs. Results TAB concentrations of accredited and nonaccredited BSCs were determined. No significant differences were observed in the TAB concentrations of the accredited BSCs and the nonaccredited BSCs for the areas outside the BSCs in the laboratories (p > 0.05). TAB concentrations for the BSCs sampled with the shield open and the instrument turned off showed differences based on the sampling site outside the BSC in each laboratory. Conclusion These results imply that TAB concentration is not altered by the performance of the BSCs or TAB itself and/or concentration of TAB outside the BSC is not a good index of BSC performance.
    03/2014; 5(1):23-6. DOI:10.1016/j.shaw.2014.01.001
  • Sung Ho Hwang, Jae Bum Park
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    ABSTRACT: In this study, we evaluated concentrations of culturable airborne bacteria (CAB) from 16 underground subway stations of Seoul Metro, Korea, between 2006 and 2013 to identify influential environmental factors, including the presence of platform screen doors (PSD), temperature, relative humidity, depth of the station, and year of construction. In total, 66 air samples were collected from all stations. Results indicated that CAB concentrations and the number of gram-negative bacteria (GNB) were significantly lower in stations with PSD and in which GNB were not detected than in stations lacking PSD and in which GNB were detected. Although there was no significant difference in CAB concentrations with variations in time, CAB concentrations of stations appeared to alter with time due to variation in the number of passengers in transit; indeed, there was a significant association between CAB concentration and the number of passengers passing through a station. The source of CAB seemed to be the poor air quality in the old subway stations. Therefore, ventilation management should be inspected more regularly, and indoor air quality should be controlled in underground subway stations.
    Atmospheric Environment 02/2014; 84:289–293. DOI:10.1016/j.atmosenv.2013.11.064 · 3.06 Impact Factor
  • Sung Ho Hwang, Jae Bum Park
    08/2013; 39(4):354-359. DOI:10.5668/JEHS.2013.39.4.354
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    ABSTRACT: We characterize the monthly variation in (1 → 3)-β-D-glucan concentration measured over the course of 1 year, and we evaluate the characteristics of size selection using a two-stage cyclone sampler. The (1 → 3)-β-D-glucan concentrations were measured in four bio-related laboratories. A total of 156 samples were collected using a new two-stage cyclone sampler. Analysis of (1 → 3)-β-D-glucan was performed using the kinetic Limulus amebocyte lysate assay. The study showed that airborne (1 → 3)-β-D-glucan concentrations were significantly higher in laboratory D (mean ± SD 1,105 ± 1,893 pg/m(3)) and in the spring (5,458 pg/m(3)). The highest concentration of (1 → 3)-β-D-glucan occurred in the spring, particularly in May.
    Environmental Monitoring and Assessment 05/2013; 185(11). DOI:10.1007/s10661-013-3212-5 · 1.68 Impact Factor
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    ABSTRACT: BACKGROUND & AIMS: Coffee consumption is inversely related to the risk of cirrhosis or hepatocellular carcinoma (HCC). However, the protective effect of coffee drinking against the risk of HCC was not established in HBV-prevalent region. To elucidate the relationship between lifetime coffee consumption and the risk of HCC development under the consideration of replication status of HBV. METHODS: A hospital-based case-control study was performed in 1364 subjects. A total of 258 HCC patients, 480 health-check examinees (control 1, HCE) and 626 patients with chronic liver disease other than HCC (control 2, CLD) were interviewed on smoking, alcohol and coffee drinking using a standardized questionnaire. HBV e-antigen (HBeAg) status and serum HBV DNA levels were measured in patients infected with HBV. RESULTS: After adjustment for age, gender, obesity, DM, presence of hepatitis virus (except for HCE) and lifetime alcohol drinking/smoking, a high lifetime coffee consumption (≥20 000 cups) was an independent protective factor against HCC, in each analyses using healthy and risky control groups respectively (HCE group, OR 0.56, 95% CI 0.33-0.95; CLD group, OR 0.55, 95% CI 0.36-0.85). However, the high coffee consumption did not affect the HCC risk in patients with HBV (OR 0.64, 95% CI 0.36-1.14) after adjustment for HBeAg status, serum HBV DNA level and antiviral therapy. CONCLUSIONS: A high lifetime coffee consumption was negatively associated with a HCC development. However, this difference of coffee exposure with the HCC group was reduced in chronic hepatitis B patients by the dominant role of viral replication.
    Liver international: official journal of the International Association for the Study of the Liver 04/2013; DOI:10.1111/liv.12186 · 4.41 Impact Factor
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    Sung Ho Hwang, Byoung Wook Choi
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    ABSTRACT: Magnetic resonance as an imaging modality provides an excellent soft tissue differentiation, which is an ideal choice for cardiac imaging. Cardiac magnetic resonance (CMR) allows myocardial tissue characterization, as well as comprehensive evaluation of the structures. Although late gadolinium enhancement after injection of the gadolinium extracellular contrast agent has further extended our ability to characterize the myocardial tissue, it also has limitations in the quantification of enhanced myocardial tissue pathology, and the detection of diffuse myocardial disease, which is not easily recognized by enhancement contrast. Recently, the remarkable advances in CMR technique, such as T1 mapping, which can quantitatively evaluate myocardial status, showed potentials to overcome limitations of existing CMR sequences and to expand the application of CMR. This article will review the technical and clinical points to be considered in the practical use of pre- and post-contrast T1 mapping.
    Korean Circulation Journal 01/2013; 43(1):1-6. DOI:10.4070/kcj.2013.43.1.1
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    ABSTRACT: Background Post-contrast T1 mapping by modified Look-Locker inversion recovery (MOLLI) sequence has been introduced as a promising means to assess an expansion of the extra-cellular space. However, T1 value in the myocardium can be affected by scanning time after bolus contrast injection. In this study, we investigated the changes of the T1 values according to multiple slicing over scanning time at 15 minutes after contrast injection and usefulness of blood T1 correction. Methods Eighteen reperfused acute myocardial infarction (AMI) patients, 13 cardiomyopathy patients and 8 healthy volunteers underwent cardiovascular magnetic resonance with 15 minute-post contrast MOLLI to generate T1 maps. In 10 cardiomyopathy cases, pre- and post-contrast MOLLI techniques were performed to generate extracellular volume fraction (Ve). Six slices of T1 maps according to the left ventricular (LV) short axis, from apex to base, were consecutively obtained. Each T1 value was measured in the whole myocardium, infarcted myocardium, non-infarcted myocardium and LV blood cavity. Results The mean T1 value of infarcted myocardium was significantly lower than that of non-infarcted myocardium (425.4±68.1 ms vs. 540.5±88.0 ms, respectively, p< 0.001). T1 values of non-infarcted myocardium increased significantly from apex to base (from 523.1±99.5 ms to 561.1±81.1 ms, p=0.001), and were accompanied by a similar increase in blood T1 value in LV cavity (from 442.1±120.7 ms to 456.8±97.5 ms, p<0.001) over time. This phenomenon was applied to both left anterior descending (LAD) territory (from 545.1±74.5 ms to 575.7±84.0 ms, p<0.001) and non-LAD territory AMI cases (from 501.2±124.5 ms to 549.5±81.3 ms, p<0.001). It was similarly applied to cardiomyopathy patients and healthy volunteers. After the myocardial T1 values, however, were adjusted by the blood T1 values, they were consistent throughout the slices from apex to base (from 1.17±0.18 to 1.25±0.13, p>0.05). The Ve did not show significant differences from apical to basal slices. Conclusion Post-contrast myocardial T1 corrected by blood T1 or Ve, provide more stable measurement of degree of fibrosis in non-infarcted myocardium in short- axis multiple slicing.
    Journal of Cardiovascular Magnetic Resonance 01/2013; 15(1):11. DOI:10.1186/1532-429X-15-11 · 5.11 Impact Factor
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    ABSTRACT: OBJECTIVES: To compare tumour enhancement patterns measured using dynamic contrast-enhanced (DCE)-CT with tumour metabolism measured using positron emission tomography (PET)-CT in patients with non-small cell lung cancer (NSCLC) and stable disease after chemotherapy or chemoradiotherapy. METHODS: After treatment, 75 NSCLC tumours in 65 patients who had stable disease on DCE-CT according to Response Evaluation Criteria in Solid Tumour (RECIST) were evaluated using PET-CT. On DCE-CT, relative enhancement ratios (RER) of tumour at 30, 60, 90, 120 s and 5 min after injection of contrast material were measured. Metabolic responses of tumours were classified into two groups according to the maximum standardized uptake value (SUVmax) by PET-CT: complete metabolic response (CR) with an SUVmax of less than 2.5, and noncomplete metabolic response (NR) with an SUVmax of at least 2.5. RESULTS: Using the optimal RER(60) cutoff value of 43.7 % to predict NR of tumour gave 95.7 % sensitivity, 64.2 % specificity, and 82.1 % positive and 95.0 % negative predictive values. After adjusting for tumour size, the odds ratio for NR in tumour with an RER(60) of at least 43.7 % was 70.85 (95 % CI = 7.95-630.91; P < 0.05). CONCLUSIONS: Even when disease was stable according to RECIST, DCE-CT predicted hypermetabolic status of residual tumour in patients with NSCLC after treatment. KEY POINTS : • Dynamic contrast-enhanced CT (DCE-CT) can provide useful metabolic information about non-small cell lung cancer. • NSCLC lesions, even grossly stable after treatment, show various metabolic states. • DCE-CT enhancement patterns correlate with tumour metabolic status as shown by PET. • DCE-CT helps to assess hypermetabolic NSCLC as stable disease after treatment.
    European Radiology 01/2013; 23(6). DOI:10.1007/s00330-012-2755-0 · 4.34 Impact Factor
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    ABSTRACT: The risk factors related to hepatitis C virus (HCV) infection showed geographic and temporal differences. We investigated HCV-related risk factors in Korea where intravenous drug use (IVDU) is uncommon. The HCV-related risk factors were investigated in a prospective, multicenter chronic HCV cohort (n = 711) using a standardized questionnaire in four university hospitals. The results were compared with those of 206 patients with chronic liver diseases not related to either of HCV or hepatitis B virus infection (comparison group). The IVDU was found in 3.9% and remote blood transfusion (≥ 20 yr ago) in 18.3% in HCV cohort group, while that in comparison group was in none and 5.3%, respectively. In a multivariate logistic analysis, transfusion in the remote past (odds ratio [OR], 2.99), needle stick injury (OR, 4.72), surgery (OR, 1.89), dental procedures (OR, 2.96), tattooing (OR, 2.07), and multiple sexual partners (2-3 persons; OR, 2.14, ≥ 4 persons; OR, 3.19), were independent risk factors for HCV infection. In conclusion, the major risk factors for HCV infection in Korea are mostly related to conventional or alterative healthcare procedures such as blood transfusion in the remote past, needle stick injury, surgery, dental procedure, and tattooing although multiple sex partners or IVDU plays a minor role.
    Journal of Korean medical science 11/2012; 27(11):1371-7. DOI:10.3346/jkms.2012.27.11.1371 · 1.25 Impact Factor
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    ABSTRACT: Background Liver function tests (LFTs) can be affected by many factors and the proposed effects of coffee on LFT require a comprehensive evaluation. The aim of this study was to elucidate whether drinking coffee, smoking, or drinking alcohol have independent effects on LFTs in Korean health-check examinees. Methods We used the responses of 500 health-check examinees, who had participated in a self-administered questionnaire survey about coffee, alcohol drinking, and smoking habits. Results Coffee consumption was closely related to male gender, high body mass index (BMI), alcohol drinking, and smoking. On univariable and multivariable analyses, drinking coffee lowered serum levels of total protein, albumin, and aspartate aminotransferases (AST). On multivariable analyses, smoking raised serum γ-glutamyl transferase (GGT) level and decreased serum protein and albumin levels, while alcohol drinking raised GGT level after adjustment for age, gender, regular medication, BMI, coffee and alcohol drinking amounts, and smoking. Conclusions Coffee consumption, smoking, and alcohol drinking affect the individual components of LFT in different ways, and the above 3 habits each have an impact on LFTs. Therefore, their effects on LFTs should be carefully interpreted, and further study on the mechanism of the effects is warranted.
    BMC Gastroenterology 10/2012; 12(1):145. DOI:10.1186/1471-230X-12-145 · 2.11 Impact Factor
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    ABSTRACT: We have previously shown that the cultured L6 myoblasts are susceptible to menadione-induced oxidative stress. Damaged cells were detached from the culture dishes. In the present study, we focused on focal adhesion kinase (FAK), which plays pivotal roles in maintaining focal adhesion function and cell survival. FAK, normally localized at the focal adhesion regions of the myoblasts, was not observed at the regions under oxidative stress induced by menadione and H(2) O(2) . Two cleavage products, 80-kDa N-terminal FAK and 35-kDa C-terminal FAK fragments, as well as full-length FAK (125 kDa) were detected in myoblasts cultured under normal conditions by western blotting with anti-N-terminal FAK or anti-C-terminal FAK sera. Of interest was the finding that the cleavage products of FAK (but not full-length FAK) disappeared under oxidative stress. The cleavage of full-length FAK to N-terminal FAK and C-terminal FAK was inhibited by calpeptin, a specific calpain inhibitor. In addition, pre-incubation of cells with calpeptin resulted in a sharp decrease in survival signals, such as Akt phosphorylation and the ratio of Bcl-2/Bax, under stress conditions. By contrast, not only relative viability, but also Akt phosphorylation and the ratio of Bcl-2/Bax was significantly improved when cells were transfected with a DNA construct of N-terminal FAK-Myc. These results suggest that the N-terminal FAK positively regulates survival signalling in early phases of oxidative stress in the cultured myoblasts.
    FEBS Journal 07/2012; 279(19):3573-83. DOI:10.1111/j.1742-4658.2012.08715.x · 3.99 Impact Factor
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    Sung Ho Hwang, Hee Jin Kim, Hye Sun Kim
    Hemophilia, 03/2012; , ISBN: 978-953-51-0429-2
  • Sung Ho Hwang, Dong Uk Park, Chung Sik Yoon
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    ABSTRACT: This study evaluated both biosafety levels (BLs) and airborne fungal concentrations in microbiological laboratories in Seoul, Korea. To evaluate biosafety facilities, we used a checklist containing 67 questions in nine categories. We also measured airborne fungal concentration according to the BLs. Airborne fungal concentrations were higher in BL-1 facilities (240 CFU/m) than in BL-2 facilities (25 CFU/m). The airborne fungal concentrations significantly differed among the laboratories that were graded as poor, fair, and good. Especially, a significant negative correlation was observed between the airborne fungal concentrations and the biosafety levels (p = 0.001). We recommend that the guidelines of biosafety be followed to improve laboratory environment.
    Human and Ecological Risk Assessment 01/2012; 19(1). DOI:10.1080/10807039.2012.701977 · 1.08 Impact Factor
  • Sung Ho Hwang, Ik Mo Lee, Chung Sik Yoon
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    ABSTRACT: We assessed in this study the total airborne bacteria (TAB), gram-negative bacteria (GNB), and endotoxin (ET) concentrations in three Korean university laboratories and two hospital diagnostic laboratories categorized as biosafety level 1 (BL 1) or biosafety level 2 (BL 2). We also investigated the concentrations of TAB, GNB, and ET relative to the performance results of biosafety cabinets (BSCs). TAB and GNB were incubated, and ET was analysed using the kinetic Limulus amebocyte lysate assay. A total of 246 (TAB = 95, GNB = 95, ET = 56) air samples were collected from nine laboratories. TAB, GNB, and ET concentrations were significantly higher in BL 1 laboratories and in laboratories that failed the BSC performance test compared to BL 2 laboratories and laboratories that passed the BSC performance test. Correlation coefficients were calculated to determine the relationships between TAB, GNB, and ET, and it was found that TAB significantly correlated with GNB (r = 0.35, p < 0.01) and ET (r = 0.29, p < 0.01). Careful attention needs to be paid to BL 1 laboratories, and BSCs should be managed on a regular basis to improve the air quality of university and hospital laboratories.
    Human and Ecological Risk Assessment 01/2012; 19(6). DOI:10.1080/10807039.2012.702601 · 1.08 Impact Factor
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    ABSTRACT: In this study, we assessed airborne endotoxin levels in university laboratories, hospital diagnostic laboratories, and a biowaste site. We also investigated indoor and outdoor sampling, sampling site, type of ventilation system, presence of open biowaste boxes, weather, and detection of Gram-negative bacteria (GNB). A total of 69 air samples were collected from 11 facilities in three institutions. Average total airborne endotoxin levels ranged from <0.01 to 10.02 EU m(-3), with an overall mean of 1.03 EU m(-3). Endotoxin levels were high in window-ventilated facilities, in facilities in which GNB were detected; levels were also high when it was rainy (all ps<0.05). Endotoxin levels were significantly correlated with humidity (r=0.70, p<0.01). The presence of HVAC; humidity; and the presence of open biowaste boxes affect endotoxin levels in laboratories.
    Chemosphere 07/2011; 85(1):135-9. DOI:10.1016/j.chemosphere.2011.06.024 · 3.50 Impact Factor
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    ABSTRACT: We wanted to validate the additional merit of the thinner coronal reformation images from multidetector CT (MDCT) for making the diagnosis of hepatic cysts. For the 90 benign hepatic cysts confirmed on MRI, the transverse (5-mm thickness) and additional coronal (2-mm thickness) reformation images from MDCT were compared with each other in terms of the Hounsfield units (HUs) and the size of each hepatic cyst. THE ATTENUATIONS (MEAN: 17.2 HUs, standard deviation: ± 14.4) on the thinner coronal images were significantly lower than those (mean: 40.7 HUs; standard deviation: ± 20.6) on the thicker transverse images for the small hepatic cysts (≤ 10 mm on the transverse image, p < 0.01). Twenty-three (79%) of the 29 cysts between 5 mm and 10 mm and 21 (51%) of 41 lesions up to 5 mm showed a mean HU value of 20 or less on the coronal reformation images. By reducing the partial volume effect, routine coronal reformation of MDCT with a thinner section thickness can provide another merit for making a confidential diagnosis of many small sub-centimeter hepatic cysts, and these small cysts are not easily characterized on the conventional transverse images.
    Korean journal of radiology: official journal of the Korean Radiological Society 05/2011; 12(3):341-50. DOI:10.3348/kjr.2011.12.3.341 · 1.81 Impact Factor

Publication Stats

265 Citations
84.93 Total Impact Points

Institutions

  • 2008–2014
    • Ajou University
      • • Department of Occupational and Environmental Medicine
      • • College of Natural Sciences
      Sŏul, Seoul, South Korea
    • Kangnam University
      Risen, Gyeonggi Province, South Korea
  • 2013
    • Yonsei University
      Sŏul, Seoul, South Korea
  • 2012–2013
    • Seoul National University Bundang Hospital
      Sŏul, Seoul, South Korea
  • 2007–2013
    • Yonsei University Hospital
      • • Department of Internal Medicine
      • • Surgery
      Sŏul, Seoul, South Korea
    • Kangbuk Samsung Hospital
      Sŏul, Seoul, South Korea
    • Konkuk University
      Sŏul, Seoul, South Korea
  • 2010–2012
    • Seoul National University
      • • Institute of Health and Environment
      • • Department of Public Health
      Sŏul, Seoul, South Korea
  • 2011
    • Chonbuk National University Hospital
      Sŏul, Seoul, South Korea
  • 2009
    • Chonbuk National University
      Tsiuentcheou, Jeollabuk-do, South Korea
  • 2008–2009
    • Sahmyook University
      Sŏul, Seoul, South Korea
  • 2005
    • Dongguk University
      Sŏul, Seoul, South Korea