배수조건에 따른 선형화된 유한변형 압밀해의 적용성 평가

최항석(CHoI Hangseok),옥영석(Oak Youngsuk),이철호(Lee Chulho),안용훈(An Yonghoon) 대한토목학회 2008 대한토목학회 학술대회 Vol.2008 No.10

F-147 : Free Paper Presentation ; An Empirical Study on Social Nicotine Dependence and Addictionsn of Alcohol, Internet, and Gambling among Medical Students

( Jeong Uk Yang ),( Chulho Oak ),( Mann Hong Jung ),( Tae Won Jang ),( Chiharu Yoshii ) 대한결핵 및 호흡기학회 2013 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.116 No.-

Medical students will be in critical position to change smokers` behavior and to educate non-smokers` knowledge about second hand smoke in the future. Many stresses from educational courses can place students at a high risk of dependence not only to smoking, but also to alcohol, gambling, or internet. The purpose of this study is to investigate addictions (alcohol, internet, gambling) and social nicotine dependence among medical students using a structured questionnaire (Kano Test for Social Nicotine Dependence; KTSND), and to examine the relationships between KTSND and demographic variables (gender, school year, religion, smoking status) and investigated variables (alcohol, internet, gambling). A cross-sectional survey was conducted on 271 medical students in a Korean medical school using a self-administered questionnaire. A significant difference was observed in KTSND scores according to gender, smoking status, and religion. The total KTSND scores were significantly different according to the degrees of alcohol addiction defined as normal, problem drinking, alcohol use disorder, and alcohol dependence (12.22±5.11, 15.24±3.68, 15.44±3.68, and 15.90±4.48, respectively, p≤0.001). The regression analysis with alcohol addiction as a dependent variable showed a significant influence by smoking status (ß=.237, t=4.154, p<.001) and social nicotine dependence (ß=.192, t=3.350, p<.01). This study demonstrated a significant correlation between the KTSND and alcohol addiction, which supports potential importance of the KTSND for concurrent treatments.Medical students will be in critical position to change smokers` behavior and to educate non-smokers` knowledge about second hand smoke in the future. Many stresses from educational courses can place students at a high risk of dependence not only to smoking, but also to alcohol, gambling, or internet. The purpose of this study is to investigate addictions (alcohol, internet, gambling) and social nicotine dependence among medical students using a structured questionnaire (Kano Test for Social Nicotine Dependence; KTSND), and to examine the relationships between KTSND and demographic variables (gender, school year, religion, smoking status) and investigated variables (alcohol, internet, gambling). A cross-sectional survey was conducted on 271 medical students in a Korean medical school using a self-administered questionnaire. A significant difference was observed in KTSND scores according to gender, smoking status, and religion. The total KTSND scores were significantly different according to the degrees of alcohol addiction defined as normal, problem drinking, alcohol use disorder, and alcohol dependence (12.22±5.11, 15.24±3.68, 15.44±3.68, and 15.90±4.48, respectively, p≤0.001). The regression analysis with alcohol addiction as a dependent variable showed a significant influence by smoking status (ß=.237, t=4.154, p<.001) and social nicotine dependence (ß=.192, t=3.350, p<.01). This study demonstrated a significant correlation between the KTSND and alcohol addiction, which supports potential importance of the KTSND for concurrent treatments.

TP-62 : Thematic Poster ; Development of Adipose Stem Cell Engraftment Model and Optical Imaging in Airway Stenosis

( Jin Young Lee ),( Chulho Oak ),( Taewon Jang ),( Mann Hong Jung ) 대한결핵 및 호흡기학회 2013 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.116 No.0

Background and Purpose: Acquired airway injury is frequently caused by endotracheal intubations, long-term tracheostomies, trauma. An effective and less invasive technique for both the early assessment and the early interventional treatment of acquired airway stenosis is therefore needed. The purpose of this study is to assess the engraftment of exogenous adipose stem cell in injured tracheal epithelium by fluorescent microscopy, to detect and monitor the degree of airway injury in the same tracheal epithelium by OCT. Method: six male New Zealand white rabbits were used for the experiment. Under intramuscular anesthesia, scrapping injury was induced by sheathed brush inserted into the trachea by way of the incised edge toward the mouth. after injury, charaterized adipose stem cells was injected into peritoneum. all rabbits were euthanized 10 days after scrapping injury. Result: Marked epithelial and mucosal layer thickening became apparent in those animals that received scrapping. Especially in the area of basement membrane, high scattering density with band like widening in comparison with normal basement membrane of uninjured tracheal epithelium. The level of thickening was significant according to epithelial thickening. Injected rASCs had been incorporated into the host trachea. significant amount of green fluorescence was observed in the rASCs-transplanted trachera, especially regenerative epithelium. Conclusion: OCT has the potential to be a high resolution imaging modality capable of detecting for airway injury in combination with stem cell imaging in same tracheal mucosa. Background and Purpose: Acquired airway injury is frequently caused by endotracheal intubations, long-term tracheostomies, trauma. An effective and less invasive technique for both the early assessment and the early interventional treatment of acquired airway stenosis is therefore needed. The purpose of this study is to assess the engraftment of exogenous adipose stem cell in injured tracheal epithelium by fluorescent microscopy, to detect and monitor the degree of airway injury in the same tracheal epithelium by OCT. Method: six male New Zealand white rabbits were used for the experiment. Under intramuscular anesthesia, scrapping injury was induced by sheathed brush inserted into the trachea by way of the incised edge toward the mouth. after injury, charaterized adipose stem cells was injected into peritoneum. all rabbits were euthanized 10 days after scrapping injury. Result: Marked epithelial and mucosal layer thickening became apparent in those animals that received scrapping. Especially in the area of basement membrane, high scattering density with band like widening in comparison with normal basement membrane of uninjured tracheal epithelium. The level of thickening was significant according to epithelial thickening. Injected rASCs had been incorporated into the host trachea. significant amount of green fluorescence was observed in the rASCs-transplanted trachera, especially regenerative epithelium. Conclusion: OCT has the potential to be a high resolution imaging modality capable of detecting for airway injury in combination with stem cell imaging in same tracheal mucosa.

Investigation of the Clinical Potential of Polarization-Sensitive Optical Coherence Tomography in a Laryngeal Tumor Model

Xin Zhou,Kim Sung Won,Oak Chulho,Kwon Daa Young,Choi Jin Hyuk,Ko Taek Yong,Kim Jun Hyeong,Tang Shuo,Ahn Yeh-Chan 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.1

BACKGROUND: The vocal cord tissue consists of three anatomical layers from the surface to deep inside: the epithelium that contains almost no collagen, the lamina propria that is composed of abundant collagen, and the vocalis muscle layer. It is clinically important to visualize the tissue microstructure using a non-invasive method, especially in the case of vocal cord nodules or cancer, since histological changes in each layer of the vocal cord cause changes in the voice. Polarization-sensitive optical coherence tomography (PS-OCT) enables phase retardation measurement to evaluate birefringence of tissue with varied organization of collagen fibers in different tissue layers. Therefore, PS-OCT can visualize structural changes between normal and abnormal vocal cord tissue. METHOD: A rabbit laryngeal tumor model with different stages of tumor progression was investigated ex-vivo by PS-OCT. A phase retardation slope-based analysis, which quantifies the birefringence in different layers, was conducted to distinguish the epithelium, lamina propria, and muscle layers. RESULTS: The PS-OCT images showed a gradual decrease in birefringence from normal tissue to advanced tumor tissue. The quantitative analysis provided a more detailed comparison among different stages of the rabbit laryngeal tumor model, which was validated by the corresponding histological findings. CONCLUSION: Differences in tissue birefringence was evaluated by PS-OCT phase retardation measurement. It is also possible to indirectly infer the dysplastic changes based on the mucosal and submucosal alterations. BACKGROUND: The vocal cord tissue consists of three anatomical layers from the surface to deep inside: the epithelium that contains almost no collagen, the lamina propria that is composed of abundant collagen, and the vocalis muscle layer. It is clinically important to visualize the tissue microstructure using a non-invasive method, especially in the case of vocal cord nodules or cancer, since histological changes in each layer of the vocal cord cause changes in the voice. Polarization-sensitive optical coherence tomography (PS-OCT) enables phase retardation measurement to evaluate birefringence of tissue with varied organization of collagen fibers in different tissue layers. Therefore, PS-OCT can visualize structural changes between normal and abnormal vocal cord tissue. METHOD: A rabbit laryngeal tumor model with different stages of tumor progression was investigated ex-vivo by PS-OCT. A phase retardation slope-based analysis, which quantifies the birefringence in different layers, was conducted to distinguish the epithelium, lamina propria, and muscle layers. RESULTS: The PS-OCT images showed a gradual decrease in birefringence from normal tissue to advanced tumor tissue. The quantitative analysis provided a more detailed comparison among different stages of the rabbit laryngeal tumor model, which was validated by the corresponding histological findings. CONCLUSION: Differences in tissue birefringence was evaluated by PS-OCT phase retardation measurement. It is also possible to indirectly infer the dysplastic changes based on the mucosal and submucosal alterations.

Awareness of Asbestos and Action Plans for Its Exposure can Help Lives Exposed to Asbestos

Lee, Hu-Jang,Park, Eun-Kee,Wilson, Donald,Tutkun, Engin,Oak, Chulho Occupational Safety and Health Research Institute 2013 Safety and health at work Vol.4 No.2

Despite the fact that asbestos is a known carcinogen to humans, it is still used in industrialized countries, especially Asian countries. The global incidence of asbestos-related diseases (ARDs) due to the past use of asbestos, continues to increase, although many countries have adopted a total ban on asbestos use. The implementation of effective strategies to eliminate ARDs is therefore an important challenge in Asia, where asbestos is still mined and consumed. Collaborative efforts and strategies at the local and international levels are vital, in the pursuit toward the elimination of ARDs in this region.

Intraoperative Real-Time Localization of Normal Parathyroid Glands With Autofluorescence Imaging

Kim, Sung Won,Song, Seo Hyun,Lee, Hyoung Shin,Noh, Woong Jae,Oak, Chulho,Ahn, Yeh-Chan,Lee, Kang Dae Issued for the Endocrine Society by the Williams & 2016 The Journal of clinical endocrinology & metabolism Vol.101 No.12

<P>Conclusions: This method showed the precise localization of the parathyroid glands and demonstrated their relation to background tissue. We believe that this simple, nonexogenous dye technique of anatomical guidance can aid surgeons to preserve parathyroid glands during thyroidectomy.</P>

광 결맞음 단층촬영법을 이용한 조직의 탄성도 측정을 위한 예비실험

권다영(Daa Young Kwon),안예찬(Yeh-Chan Ahn),옥철호(Chulho Oak),박은기(Eun-Kee Park) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

적외선 자가형광 이미징을 이용한 수술 중의 부갑상선 위치확인

안예찬(Yeh-Chan Ahn),송서현(Seo Hyun Song),김성원(Sung Won Kim),이형신(Hyoung Shin LEE),옥철호(Chulho Oak),이강대(Kang Dae Lee) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

Near-infrared Transillumination and Photodynamic Therapy Using Hypericin in Animal Laryngeal Tumors

Lee Haeyoung,김성원,권다영,Kang Hyun Wook,Jung Min-Jung,Kim Jun Hyeong,Ahn Yeh-Chan,Oak Chulho 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.6

Background: We aimed to validate a pilot study of photodiagnosis using near infrared (NIR) transillumination and assess the clinical efficacy of hypericin-mediated photodynamic therapy (HYP-PDT) in a rabbit laryngeal cancer model in order to develop a novel therapeutic modality with complete remission and preservation of the functional organ. Methods: (1) In vitro study: VX tumor cells were subcultured and subjected to HYP-PDT. (2) In vivo study: A laryngeal cancer model was developed in which 12 rabbits were inoculated with a VX tumor suspension in the submucosal area of the left vocal fold using a transoral approach. All rabbits underwent NIR transillumination using light with a wavelength of 780 nm. The survival periods of the three treatment groups (6 rabbits in Group A: HYP-PDT, 3 each in Groups B and C: laser irradiation or HYP administration only) were analyzed. Results: The higher the HYP concentration, the lower the VX cell viability in response to HYP-PDT using 590 nm LED. Following HYP-PDT, small tumors in Group A-1 rabbits healed completely and the animals demonstrated a long survival period, and larger tumors in Group A-2 healed partially with a survival period that extended over 3 weeks after inoculation. The survival of Groups B and C were not different over the first 3 weeks of the study, and were shorter than in Group A. Conclusion: We found HYP-PDT could be a curative therapy for early-stage cancers that may also preserve organ function, and may inhibit tumor progression and metastasis during advanced stages of laryngeal cancer. Background: We aimed to validate a pilot study of photodiagnosis using near infrared (NIR) transillumination and assess the clinical efficacy of hypericin-mediated photodynamic therapy (HYP-PDT) in a rabbit laryngeal cancer model in order to develop a novel therapeutic modality with complete remission and preservation of the functional organ. Methods: (1) In vitro study: VX tumor cells were subcultured and subjected to HYP-PDT. (2) In vivo study: A laryngeal cancer model was developed in which 12 rabbits were inoculated with a VX tumor suspension in the submucosal area of the left vocal fold using a transoral approach. All rabbits underwent NIR transillumination using light with a wavelength of 780 nm. The survival periods of the three treatment groups (6 rabbits in Group A: HYP-PDT, 3 each in Groups B and C: laser irradiation or HYP administration only) were analyzed. Results: The higher the HYP concentration, the lower the VX cell viability in response to HYP-PDT using 590 nm LED. Following HYP-PDT, small tumors in Group A-1 rabbits healed completely and the animals demonstrated a long survival period, and larger tumors in Group A-2 healed partially with a survival period that extended over 3 weeks after inoculation. The survival of Groups B and C were not different over the first 3 weeks of the study, and were shorter than in Group A. Conclusion: We found HYP-PDT could be a curative therapy for early-stage cancers that may also preserve organ function, and may inhibit tumor progression and metastasis during advanced stages of laryngeal cancer.

Application of Polarization Sensitive-Optical Coherence Tomography to the Assessment of Phase Retardation in Subpleural Cancer in Rabbits

Park Jung-Eun,Xin Zhou,Kwon Daa Young,Kim Sung Won,Lee Haeyoung,Jung Min-Jung,Tang Shuo,Ko Taek Yong,Choi Jin Hyuk,Kim Jun Hyeong,Ahn Yeh-Chan,Oak Chulho 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.1

Background: Polarization sensitive-optical coherence tomography (PS-OCT) provides the unique advantage of being able to measure the optical characteristics of tissues by using polarized light. Although the well-organized fibers of healthy muscle can change the polarization states of passing light, damaged tissue has different behaviors. There are studies on optical imaging methods applied to the respiratory organs; however, they are restricted to structural imaging. In particular, the intercostal muscle situated under the pleura is very challenging to visualize due to the difficulty of access. Method: In this study, PS-OCT was used to identify subpleural cancer in male New Zealand white rabbits (3.2–3.4 kg) and to assess the phase retardation changes in normal and cancerous chest walls. VX2 cell suspension was injected between the intercostal muscle and parietal pleura and a tented area was observed by thoracic scope. A group of rabbits (n = 3) were sacrificed at day 7 after injection and another group (n = 3) at day 14. Results: In the PS-OCT images, pleura thickness changes and muscle damage were criteria to understand the stages of the disease. The results of image and phase retardation analysis matched well with the pathologic examinations. Conclusion: We were able to visualize and analyze subpleural cancer by PS-OCT, which provided structural and functional information. The measured phase retardation could help to identify the margin of the tumor. For further studies, various approaches into other diseases using polarization light are expected to have positive results. Background: Polarization sensitive-optical coherence tomography (PS-OCT) provides the unique advantage of being able to measure the optical characteristics of tissues by using polarized light. Although the well-organized fibers of healthy muscle can change the polarization states of passing light, damaged tissue has different behaviors. There are studies on optical imaging methods applied to the respiratory organs; however, they are restricted to structural imaging. In particular, the intercostal muscle situated under the pleura is very challenging to visualize due to the difficulty of access. Method: In this study, PS-OCT was used to identify subpleural cancer in male New Zealand white rabbits (3.2–3.4 kg) and to assess the phase retardation changes in normal and cancerous chest walls. VX2 cell suspension was injected between the intercostal muscle and parietal pleura and a tented area was observed by thoracic scope. A group of rabbits (n = 3) were sacrificed at day 7 after injection and another group (n = 3) at day 14. Results: In the PS-OCT images, pleura thickness changes and muscle damage were criteria to understand the stages of the disease. The results of image and phase retardation analysis matched well with the pathologic examinations. Conclusion: We were able to visualize and analyze subpleural cancer by PS-OCT, which provided structural and functional information. The measured phase retardation could help to identify the margin of the tumor. For further studies, various approaches into other diseases using polarization light are expected to have positive results.