토끼 태자에 형성시킨 구순열상의 치유과정에서 수종 성장인자 분포에 관한 연구

백승학,양원식 대한치과교정학회 1997 대한치과교정학회지 Vol.27 No.5

성체의 상처 치유과정 중 반흔조직 형성에 수종의 성장인자가 관련이 있는 것으로 보고되고 있으나, 태자의 피부상처가 반흔형성없이 치유되는 기전에 관한 성장인자의 역할은 아직 알려져 있지 않다. 따라서 본 연구의 목적은 토끼 태자의 상처 치유과정에서 반흔조직의 형성과 관련이 있는 수종 성장인자의 분포를 조사하기 위한 것이다. 뉴질랜드산 흰 토끼를 임신 3기의 중반인 24일째에 자궁절개술을 시행하고 태자에 인위적으로 구순열상을 만든후, 봉합한 군(봉합군)과 봉합하지 않은 군(비봉합군), 정상대조군(sham operated control group)으로 나누고 이들을 각각 수술후 1, 2, 3, 5, 7일째에 희생시켜 상처치유에 대한 육안관찰 소견과 H&F염색소견 및 TGF-β1, TGF-β2, PDGF, bFGF의 면역조직화학적 염색 소견을 관찰하여 다음과 같은 결론을 얻었다. 1. 봉합군과 비봉합군에서 전기간동안 염증반응과 반흔조직의 형성 그리고 신생 혈관의 형성 증가는 없었다. 2. 비봉합군의 재상피화가 봉합군에 비해 다소 느렸다. 3. bFGF는 정상대조군, 봉합군과 비봉합군에서 차이가 없었다. 4. PDGF는 봉합군과 비봉합군에서 1, 2일군에서 증가하였다가 그후 감소하여 정상대조군과 차이가 없었다. 5. TGF-β는 봉합군과 비봉합군에서 1, 2일군에서 약간 증가하였다가 그후 감소하여 정상대조군과 차이가 없었다. TGF-β1에 비하여 TGF-β2의 검출양이 많았다. Recently several growth factors such as TGF-β1, TGF-β2, PDGF, bFGF are known to play an important role in scar formation following adult tissue injury. But there is little known about the role of growth factors in fetal tissue healing without scar formation. Therefore the purpose of this study is to investigate the distribution of growth factors which are involved with scar formation in the artificially created cleft lip wound healing of fetuses. The author had undergone hysterotomy and created cleft lip-like defects on fetuses of New Zealand White Rabbit in mid-third trimester(24 days). Fetuses were divided into 3 groups(the repaired group, the unrepaired group and the sham-operated control group). At 1, 2, 3, 5, 7days after procedure, the repaired, the unrepaired and the control groups were obtained by Caeserean section. After documenting the viability of fetuses, fetuses were photographed to compare size and facial morphology and sectioned for histological examination by H & E stain and spatial and temporal deposition of TGF-β1, TGF-β2, PDGF, bFGF by immunohistochemical method. The findings are summarized as follows 1. There were lack of inflammation and scar formation and neovascularity in the repaired and the unrepaired group during experimental periods. 2. The reepithelialization of the unrepaired group was slower than that of repaired group. 3. There were no differences of distribution of bFGF in the control, the repaired and the unrepaired group. 4. PDGF was increased at post-op. first and second day and decreased after post-op. third day. Eventually, there were no differences in the control, the repaired and the unrepaired group. 5. TGF-β1 and TGF-β2 were slightly increased at post-op. first and second day and decreased after post-op. third day. Eventually there were no differences in the control, the repaired and the unrepaired group. And TGF-β2 is more densely stained than TGF-β1.

뼈에 발생한 악성 림프종 환자의 치료 효과 판정에서 ^(18)F-FDG Positron Emission Tomography의 유용성

김남돈,박연희,기승석,박용진,김형준,류백렬,김흥태,김성은,천기정,최창운,임상무 대한핵의학회 2003 핵의학 분자영상 Vol.37 No.5

원발성골림프종은 매우 드문 질환이기는 하나, 복합항암요법이나 방사선 치료등에 높은 반응율을 보이며, 좋은 예후를 가지는 림프절의 비호지킨 림프종의 일종이다. 그러나, 치료 효과 판정에 있어 골병변의 특이성에 의한 모호한 방사선학적 특징으로 어려움이 있어 왔다. 본 증례는 위와 같은 원발성골림프종 환자에서 PET 스캔을 사용하여 민감하게 완전 반응을 평가할 수 있었던 예로, 앞으로 다른 고식적인 방법과 함께 이 질환의 진단과 치료 평가 있어 유용하게 사용 될 수 있을 것으로 전망할 수 있었다. Purpose: Accurate assessment of the lesion after treatment of patients with bone lymphoma is difficult. In this patient who demonstrated complete remission after chemotherapy, the regions of fluorine-18 fluorodeoxyglucose (^(18)FFDG)PET uptake diminished more rapidly following therapy, indicating a complete response at much earlier stage than did Magnetic Resonance Imaging (MRI) or CT based findings. With the conventional methods, such as MRI and CT. It was difficult to assess whether the residual tumor tissue was viable or not. Decision to complete response is very important in patients with ymphoma to plan the further treatment. We experienced a patient with primary lymphoma of bone who revealed complete response to chemotherapy on ^(18)FFDGPET while CT showed persistent destructive bone lesion. Thus, ^(18)FFDGPET study after therapy may be superior to CT in the evaluation of response to treatment in primary lymphoma of bone.

Reduced restenosis and enhanced re-endothelialization of functional biodegradable vascular scaffolds by everolimus and magnesium hydroxide

Baek Seung-Woon,Kim Da-Seul,Song Duck Hyun,Kim Han Byul,Lee Semi,김준혁,Lee Jun-Kyu,Hong Young Joon,Park Chun Gwon,Han Dong Keun 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Coronary artery disease is a cardiovascular disease with a high mortality and mortality rate in modern society. Vascular stent insertion to restore blood flow is essential to treat this disease. A fully biodegradable vascular scaffold (BVS) is a vascular poly (L-lactic acid) (PLLA) stent that is receiving growing interest as this is biodegradable in the body and does not require secondary removal surgery. However, acidic byproducts composed of PLLA produced during the biodegradation of the BVS can induce an inflammatory response. Magnesium hydroxide, a basic inorganic particle, neutralizes the acidic byproducts of PLLA. In this study, we investigated using a BVS coated with everolimus and surface-modified magnesium hydroxide that suppresses smooth muscle cell proliferation and protects endothelial cells, respectively. The various characteristics of the functional stent were evaluated using in vitro and in vivo analyses. The BVS was successfully prepared with evenly coated everolimus and surface-modified magnesium hydroxide. A neutral pH value was maintained by magnesium hydroxide during degradation, and everolimus was released for one month. The coated BVS effectively inhibited protein adsorption and platelet adhesion, demonstrating excellent blood compatibility. In vitro analysis showed that BVS protects endothelial cells with magnesium hydroxide and selectively inhibits smooth muscle cell proliferation via everolimus treatment. The functional BVS was inserted into porcine coronary arteries for 28 days, and the results demonstrated that the restenosis and inflammation greatly decreased and re-endothelialization was enhanced as compared to others.This study provides new insights into the design of drug-incorporated BVS stent for coronary artery disease.

Bulk Modification with Inorganic Particles and Immobilization of Extracellular Vesicles onto PDO Composite for Facial Rejuvenation

Baek Seung-Woon,Kim Dong Min,Lee Semi,Song Duck Hyun,Park Gi-Min,Park Chun Gwon,Han Dong Keun 한국조직공학과 재생의학회 2024 조직공학과 재생의학 Vol.21 No.2

BACKGROUND: The skin, a vital organ protecting against microorganisms and dehydration, undergoes structural decline with aging, leading to visible issues such as wrinkles and sagging. Reduced blood vessels exacerbate vulnerability, hindering optimal cellular function and compromising skin health. Polydioxanone (PDO) biomaterials address aging concerns but produce acidic byproducts, causing inflammation. Inorganic particles and nitric oxide (NO) play crucial roles in inhibiting inflammation and promoting skin regeneration. Stem cell-derived extracellular vesicles (EVs) contribute to intercellular communication, offering the potential to enhance cell functions. The study proposes a method to enhance PDO-based medical devices by incorporating inorganic particles and immobilizing EVs, focusing on facial rejuvenation, anti-inflammatory response, collagen formation, and angiogenesis. METHOD: PDO composites with inorganic particles such as magnesium hydroxide (MH) and zinc oxide (ZO) were prepared and followed by EV immobilization. Comprehensive characterization included biocompatibility, anti-inflammation, collagen formation ability, and angiogenesis ability. RESULTS: Bulk-modified PDO composites demonstrated even dispersion of inorganic particles, pH neutralization, and enhanced biocompatibility. EVs immobilized on the composite surface exhibited spherical morphology. Inflammation-related gene expressions decreased, emphasizing anti-inflammatory effects. Collagen-related gene and protein expressions increased, showcasing collagen formation ability. In addition, angiogenic capabilities were notably improved, indicating potential for skin rejuvenation. CONCLUSION: The study successfully developed and characterized PDO composites with inorganic particles and EVs, demonstrating promising attributes for medical applications. These composites exhibit biocompatibility, anti-inflammatory properties, collagen formation ability, and angiogenic potential, suggesting their utility in skin rejuvenation and tissue engineering. Further research and clinical validation are essential. BACKGROUND: The skin, a vital organ protecting against microorganisms and dehydration, undergoes structural decline with aging, leading to visible issues such as wrinkles and sagging. Reduced blood vessels exacerbate vulnerability, hindering optimal cellular function and compromising skin health. Polydioxanone (PDO) biomaterials address aging concerns but produce acidic byproducts, causing inflammation. Inorganic particles and nitric oxide (NO) play crucial roles in inhibiting inflammation and promoting skin regeneration. Stem cell-derived extracellular vesicles (EVs) contribute to intercellular communication, offering the potential to enhance cell functions. The study proposes a method to enhance PDO-based medical devices by incorporating inorganic particles and immobilizing EVs, focusing on facial rejuvenation, anti-inflammatory response, collagen formation, and angiogenesis. METHOD: PDO composites with inorganic particles such as magnesium hydroxide (MH) and zinc oxide (ZO) were prepared and followed by EV immobilization. Comprehensive characterization included biocompatibility, anti-inflammation, collagen formation ability, and angiogenesis ability. RESULTS: Bulk-modified PDO composites demonstrated even dispersion of inorganic particles, pH neutralization, and enhanced biocompatibility. EVs immobilized on the composite surface exhibited spherical morphology. Inflammation-related gene expressions decreased, emphasizing anti-inflammatory effects. Collagen-related gene and protein expressions increased, showcasing collagen formation ability. In addition, angiogenic capabilities were notably improved, indicating potential for skin rejuvenation. CONCLUSION: The study successfully developed and characterized PDO composites with inorganic particles and EVs, demonstrating promising attributes for medical applications. These composites exhibit biocompatibility, anti-inflammatory properties, collagen formation ability, and angiogenic potential, suggesting their utility in skin rejuvenation and tissue engineering. Further research and clinical validation are essential.

Shellac Films as a Natural Dielectric Layer for Enhanced Electron Transport in Polymer Field-Effect Transistors

Baek, Seung Woon,Ha, Jong-Woon,Yoon, Minho,Hwang, Do-Hoon,Lee, Jiyoul American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.22

<P>Shellac, a natural polymer resin obtained from the secretions of lac bugs, was evaluated as a dielectric layer in organic field-effect transistors (OFETs) on the basis of donor (D)-acceptor (A)-type conjugated semiconducting copolymers. The measured dielectric constant and breakdown field of the shellac layer were ∼3.4 and 3.0 MV/cm, respectively, comparable with those of a poly(4-vinylphenol) (PVP) film, a commonly used dielectric material. Bottom-gate/top-contact OFETs were fabricated with shellac or PVP as the dielectric layer and one of three different D-A-type semiconducting copolymers as the active layer: poly(cyclopentadithiophene-<I>alt</I>-benzothiadiazole) with p-type characteristics, poly(naphthalene-bis(dicarboximide)-<I>alt</I>-bithiophene) [P(NDI2OD-T2)] with n-type characteristics, and poly(dithienyl-diketopyrrolopyrrole-<I>alt</I>-thienothiophene) [P(DPP2T-TT)] with ambipolar characteristics. The electrical characteristics of the fabricated OFETs were then measured. For all active layers, OFETs with a shellac film as the dielectric layer exhibited a better mobility than those with PVP. For example, the mobility of the OFET with a shellac dielectric and n-type P(NDI2OD-T2) active layer was approximately 2 orders of magnitude greater than that of the corresponding OFET with a PVP insulating layer. When P(DPP2T-TT) served as the active layer, the OFET with shellac as the dielectric exhibited ambipolar characteristics, whereas the corresponding OFET with the PVP dielectric operated only in hole-accumulation mode. The total density of states was analyzed using technology computer-aided design simulations. The results revealed that compared with the OFETs with PVP as the dielectric, the OFETs with shellac as the dielectric had a lower trap-site density at the polymer semiconductor/dielectric interface and much fewer acceptor-like trap sites acting as electron traps. These results demonstrate that shellac is a suitable dielectric material for D-A-type semiconducting copolymer-based OFETs, and the use of shellac as a dielectric layer facilitates electron transport at the interface with D-A-type copolymer channels.</P> [FIG OMISSION]</BR>

이온 플레이팅의 TiN코팅층에 미치는 작업인자의 영향

백운승(Woon-Seung Baek),권식철(Sik-Chol Kwon),이상로(Sang-Ro Lee),이건환(Gun-Whan Lee) 한국표면공학회 1990 한국표면공학회지 Vol.23 No.2

배전계통 시뮬레이터와 운영시스템의 DNP 통신 연계 시 이벤트 처리에 대한 시간동기화 연구

백지운(Ji-Woon Baek),김형승(Hyung-Seung Kim),김태완(Tae-Wan Kim),최면송(Myeon-Song Choi),이승재(Seung-Jae Lee) 대한전기학회 2019 대한전기학회 학술대회 논문집 Vol.2019 No.7

Twelve-month clinical outcomes of acute non-ST versus ST-segment elevation myocardial infarction patients with reduced preprocedural thrombolysis in myocardial infarction flow undergoing percutaneous coronary intervention

Baek, Ju Yeol,Kang, Tae Soo,Rha, Seung-Woon,Choi, Byoung Geol,Park, Sang Ho,Jeong, Myung Ho Wolters Kluwer Health, Inc. All rights reserved. 2018 Coronary artery disease Vol.29 No.5

<P>BackgroundReduced preprocedural thrombolysis in myocardial infarction (TIMI) flow in patients with ST-segment elevation myocardial infarction (STEMI) is known to be associated with increased mortality. However, clinical implications of reduced preprocedural TIMI flow in patients with non-ST-segment elevation myocardial infarction (NSTEMI) have not been fully elucidated as yet. The aim of the present study was to compare the clinical influence of reduced preprocedural TIMI flows between patients with STEMI and NSTEMI undergoing percutaneous coronary intervention (PCI).MethodsFrom the Korea Acute Myocardial Infarction Registry, a total of 7336 AMI patients with angiographically confirmed reduced preprocedural TIMI flow (TIMI 0/1) during PCI were selected and divided into STEMI (n=4852) and NSTEMI (n=2484) groups. The 12-month composite of total death, nonfatal myocardial infarction, coronary artery bypass graft, and repeated PCI was compared between the two groups.ResultsAfter adjustment of baseline confounders by propensity score stratification, the NSTEMI group had lower incidences of major adverse cardiac events than the STEMI group (7.15 vs. 11.19%; hazard ratio: 0.63; 95% confidence interval: 0.47-0.84; P=0.001) at 12 months, which was largely attributable to the lower incidences of total deaths (2.43 vs. 3.99%; P=0.04) and repeated PCI (3.81 vs. 6.41%; P=0.01).ConclusionAmong AMI patients with TIMI 0/1, patients with NSTEMI had better outcomes compared with those of patients with STEMI on the basis of the incidences of 12-month outcomes. This could be attributable to lower total death and repeated revascularization in patients with NSTEMI.</P>

Localization of Hydrogen Peroxide in Pumpkin (Cucurbita ficifolia Bouche) Seedlings Exposed to High-Dose Gamma Ray

( Seung Gon Wi ),( Byung Yeoup Chung ),( Jae Sung Kim ),( Jin Hong Kim ),( Myung Hwa Baek ),( Ju Woon Lee ) 한국식물학회 2006 Journal of Plant Biology Vol.49 No.1

A case of diffuse alveolar hemorrhage presented with the gastrointestinal symptoms

Baek, Ki-hwan,Keum, Seung-woon,Oh, Yeon-kyun,Kim, Jong-duck,Yu, Seung-taek 원광대학교 의과학연구소 2009 圓光醫科學 Vol.24 No.1

Diffuse alveolar hemorrhage(DAH) is a potentially fatal condition. DAH may occur independently or in junction with other systemic disorders. Idiopathic pulmonary hemosiderosis(IPH) is referred to as an isolated DAH without any identifiable causation or associated systemic diseases. DAH may be associated with or without histopathologic evidence of pulmonary capillaritis(PC). PC is small-vessel vasculitis, which remains poorly understood. We have reported a case of the pulmonary hemorrhage. The infant did not have any respiratory symptoms and demonstrated only abdominal distension; however, during abdominal computed tomography(CT) examination with enhancement, she developed abrupt diffuse pulmonary hemorrhage and deterioration of her mental functions. After admission for 15 days, symptomatic improvement was shown and she was discharged. Therefore, we have reported a case of diffuse alveolar hemorrhage associated with gastrointestinal symptoms.