생체분해성 고분자의 특성 및 의학적 응용

이진호,최선웅,강길선,노승무,민병무,김용백,김학용 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

"Biomaterials" are nonviable materials used in medical devices, intended to interact with biological systems. They should have "biocompativility", which is defined as the ability of materials to perform with an appropriate host response in a specific application. It includes many materials that are often classified as biomaterials. Metals, ceramics, polymers, glasses, carbons, and composite materials are some examples. Among them, biodegradable polymers are discussed in this revies article. Since a biodegradable polymeric implant does not have to be removed surgically once it is no longer needed, biodegradable polymers are of value in short-term applications that require only the temporary presence of a polymeric implant. Main short-term medical applications of biodegradable polymers include the temporary tissue scaffold, the temporary adhesion barrier, the drug delivery device, and the multifunctional implant. In this article, the properties, processing methods, and medical applications of the biodegradable polymers are reviewed.

Before Coronary CTO PCI: Burden or Location?

Woong Gil Choi 대한심장학회 2022 Korean Circulation Journal Vol.52 No.2

The effect of antiplatelet drug on coronary endothelial and microvascular function: comparison with ticagrelor and clopidogrel

( Woong Gil Choi ),( Gi Chang Kim ),( Cheol Ho Lee ),( Hye Young Kim ),( Dong Woon Kim ) 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.2

Background/Aims: Coronary endothelial and microvascular function play important roles in cardiovascular disease. We aimed to evaluate the effect of ticagrelor on coronary artery function and tested the antiplatelet effect of low dose ticagrelor in East-Asian patients. Methods: Sixty-one consecutive patients with non-significant coronary disease were included in the study. Initially, patients were randomized in 1:1:1 ratio to receive drugs: ticagrelor 90 mg twice a day (bid; n = 22), ticagrelor 45 mg bid (n = 19) or clopidogrel 75 mg once a day (qd; n = 20) and then divided into two groups (ticagrelor vs clopidogrel) for evaluation of coronary artery function, and three groups for evaluation of antiplatelet function. Endothelial dysfunction was measured by coronary flow reserve (CFR), and changes in the levels of asymmetric dimethylarginine (ADMA), cluster of differentiation (CD) 40 ligand, and P-selectin. Microvascular function was evaluated as index of microvascular resistance (IMR). Platelet reactivity was assessed by VerifyNow P2Y12 assay. Results: The levels of CFR, ADMA, and CD 40 ligand were not different between the two groups. However, P-selectin was lower in the ticagrelor group compared with clopidogrel group. IMR was significantly lower in the ticagrelor group compared with clopidogrel group (median, 15.0 [interquartile range, 12.0 to 21.0] vs. 47.5 [23.0 to 67.5], p = 0.014). There was significant difference in platelet inhibition among the three groups (ticagrelor 90 mg bid vs. ticagrelor 45 mg bid vs. clopidogrel 75 mg qd; 85.57 ± 47.63 vs. 120.33 ± 51.09 vs. 256.42 ± 55.10, p < 0.001) Conclusions: It is hypothesized that ticagrelor might ameliorate the coronary microvascular function. When compared with clopidogrel, low dose ticagrelor exhibited satisfactory antiplatelet effect in the present study.

Impact of an endothelial progenitor cell capturing stent on coronary microvascular function: comparison with drug-eluting stents

( Woong Gil Choi ),( Soo Hyun Kim ),( Hyung Seok Yoon ),( Eun Joo Lee ),( Dong Woon Kim ) 대한내과학회 2015 The Korean Journal of Internal Medicine Vol.30 No.1

Background/Aims: Although drug-eluting stents (DESs) effectively reduce restenosis following percutaneous coronary intervention (PCI), they also delay re-endothelialization and impair microvascular function, resulting in adverse clinical outcomes. Endothelial progenitor cell (EPC) capturing stents, by providing a functional endothelial layer on the stent, have beneficial effects on microvascular function. However, data on coronary microvascular function in patients with EPC stents versus DESs are lacking. Methods: Seventy-four patients who previously underwent PCI were enrolled in this study. Microvascular function was evaluated 6 months after PCI based on the index of microvascular resistance (IMR) and the coronary flow reserve (CFR). IMR was calculated as the ratio of the mean distal coronary pressure at maximal hyperemia to the inverse of the hyperemic mean transit time (hTmn). The CFR was calculated by dividing the hTmn by the baseline mean transit time. Results: Twenty-one patients (age, 67.2 ± 9.6 years; male:female, 15:6) with an EPC stent and 53 patients (age, 61.5 ± 14.7 years; male:female, 40:13) with second-generation DESs were included in the study. There were no significant differences in the baseline clinical and angiographic characteristics of the two groups. Angiography performed 6 months postoperatively did not show significant differences in their CFR values. However, patients with the EPC stent had a significantly lower IMR than patients with second-generation DESs (median, 25.5 [interquartile range, 12.85 to 28.18] vs. 29.0 [interquartile range, 15.42 to 39.23]; p = 0.043). Conclusions: Microvascular dysfunction was signif icantly improved after 6 months in patients with EPC stents compared to those with DESs. The complete re-endothelialization achieved with the EPC stent may provide clinical benefits over DESs, especially in patients with microvascular dysfunction.

도축 한우의 복강내 지방괴사증 발생과 병리조직학적 연구

최길성 ( Gil Seong Choi ),임채웅 ( Chae Woong Lim ),채효석 ( Hyo Seok Chai ),최인열 ( In Yeol Choi ),이성효 ( Sung Hyo Lee ),김추철 ( Chu Cheul Kim ),서문정 ( Moon Jeong Suh ) 한국가축위생학회 1999 韓國家畜衛生學會誌 Vol.21 No.1

The bovine fat necrosis is often seen as an incidental lesion in the adipose tissues of the abdominal cavity. Most of affected animals, however, have been detected at the slaughter house or routine necropsy. The purpose of this study was to examine the occurrence and distribution of abdominal fat necrosis in Korean native cattle, and its pathologic features. Postmortem inspection at an Chonju abattoir during a three-month period in 1997 detected at necrosis lesions in 67(6.6%) of the 1,012 animals received for slaughter. The occurrence was mainly in alimentary tracts and perirenal. Both sexes were affected, but the lesions were predominantly occurred in female. Gross lesions were white or yellowish in color and formed hard lumps irregular in shape ranging from small nodules to large solid masses. On the cut surface, lesions were occasionally seen chalky calcified granules and some of the lesions contained oil-like fluid. The surface of irregular shaped masses constricted kidneys and intestinal loops. Microscopically, the masses were encapsulated by thickened fibrous tissue, which infiltrated deeply and divided them into many irregular lobules. Initial lesions presented mild inflammatory cell and fibrous proliferation. It became fibroplasia in progressive lesions and resembled chronic lesion, eventhough no grossly apparent inflammatory reaction. The hard consistency of masses, due to fibroplasia, can compress the intestines, urinary organs, and reproductive organs.

전신성 홍반성 루푸스 환자에서 면역 억제 요법 후 발생한 카포시 육종

최웅길 ( Woong Gil Choi ),김준미 ( Joon Mee Kim ),권성렬 ( Seong Ryul Kwon ),이문희 ( Moon Hei Lee ),이진수 ( Jin Soo Lee ),박원 ( Won Park ) 대한류마티스학회 2006 대한류마티스학회지 Vol.13 No.1

A 41-year-old woman was admitted because of dyspnea on exertion for one month. She was diagnosed to have systemic lupus erythematosus 4 years ago and has taken prednisolone and azathioprine. One month prior to admission she visited dental clinic for painful gingival swelling and gingival biopsy was performed. Physical examination showed multiple round elevated purpuric rashes in thoracic wall. Gingiva and skin biopsy showed Kaposi`s sarcoma. Computed tomography of abdomen and chest revealed ill-defined nodules in both lung fields and multiple small para-aortic lymphadenopathies. Chemotherapy with paclitaxel was given for Kaposi`s sarcoma. Prednisolone was tapered. After the 7th course of chemotherapy, the lesions show marked improvement in size and number.

급성 심근 경색 환자에서 재관류 방법에 따른 P파폭과 P파 분산의 변화

최웅길 ( Woong Gil Choi ),김대혁 ( Dae Hyeok Kim ),김기창 ( Gi Chang Kim ),안인선 ( In Sun Ahn ),김수현 ( Soo Hyun Kim ),유형권 ( Hyung Kwon Yu ),권준 ( Jun Kwan ),박금수 ( Keum Soo Park ),이우형 ( Woo Hyung Lee ) 대한내과학회 2007 대한내과학회지 Vol.73 No.5

목적: 급성 심근경색증 환자에서 심방세동은 10~20%의 빈도로 발생되는 흔한 부정맥이다. 최대 P파 폭과 P파 분산은 심방세동의 전기생리학적 특성과 연관된 동성 흥분파의 비균질 전도, 심방내 전도장애와 밀접히 연관된 것으로 알려져 있다. 이 연구의 목적은 급성 심근경색증 환자의 재관류 치료 방법이 최대 P파의 폭과 P파 분산에 대해 미치는 효과를 비교 분석하였다. 방법: 2005년 5월부터 2006년 5월까지 급성 심근경색으로 본원에 내원한 86명의 환자를 대상으로 응급실내원 당시의 모든 환자의 심전도와 일차적 관상동맥 중재술, 혈전용해요법을 시행 받은 환자 군은 치료 2일 후에 지연 관상동맥 중재술로 예정된 환자는 입원 2일 후의 심전도에서 최대 P파 폭과 P파 분산을 측정하여 각 군 간의 차이를 분석하였다. 결과: 일차적 관상동맥 중재술, 혈전용해요법, 지연관상동맥 중재술을 시행한 환자는 각각 28명, 27명 그리고 31명이었다. 일차적 관상동맥 중재술을 시행한 군이 다른 치료전략을 시행한 군에 비해 시술 후 최대 P파 폭과 P파 간격 분산이 다른 군에 비해 유의하게 감소하였으나, 혈전용해요법과 지연 관상동맥 중재술간의 치료후 유의한 차이는 없었다. 혈전용해요법과 지연 관상동맥 중재술을 시행한 경우 경색관련 관상동맥의 개존성이 있었던 군에서 개존성이 없었던 군에 비해 2일 후 P파 분산이 의미있게 감소하였다. 결론: 급성 심근경색증 환자에서 일차적 관상동맥중재술 군이 치료 후 최대 P파 폭과 P파 분산이 의미있게 감소하였다. Background: P wave dispersion (PWD) and P wave duration have been used to evaluate the discontinuous propagation of sinus impulse and the prolongation of atrial conduction time, respectively. This study was conducted to compare the change of the maximal P wave duration (Pmax) and PWD according to the treatment strategy used in patients with an acute myocardial infarction (AMI). Methods: We retrospectively evaluated 86 patients that experienced an AMI. Patients were classified into three groups according to the treatment strategy: primary percutaneous coronary intervention (PCI), thrombolytic therapy, and delayed PCI. ECGs that were obtained from all patients on admission and on the second day were analyzed. The Pmax and minimum P wave duration (Pmin) were measured from a 12-lead ECG. The PWD was calculated as the difference between the Pmax and Pmin. Result: There was no significant difference in the age, gender, medication, coronary risk factor, ejection fraction, left atrial diameter, basal Pmax and PWD among the groups. However, there were significant differences in P max and PWD between the primary PCI group and the other groups on the second day after hospital admission. In the thrombolytic therapy and delayed PCI groups, the PWD was significantly lower in the patients with a patent infarct-related artery (IRA) than in patients without a patent IRA on the second day after hospital admission. Conclusions: These findings suggest that a primary PCI decreased the Pmax and PWD more than thrombolytic therapy or a delayed PCI.(Korean J Med 73:489-495, 2007)

Impact of Cigarette Smoking: a 3-Year Clinical Outcome of Vasospastic Angina Patients

Byoung Geol Choi,Seung-Woon Rha,Taeshik Park,Se Yeon Choi,Jae Kyeong Byun,Min Suk Shim,Shaopeng Xu,Hu Li,Sang-Ho Park,Ji Young Park,Woong Gil Choi,Yun-Hyeong Cho,이선기,Jin Oh Na,Cheol Ung Choi,Hong Euy 대한심장학회 2016 Korean Circulation Journal Vol.46 No.5

However, it is largely unknown whether smoking adds to any long-term clinical risk in VSA patients. Subjects and Methods: A total of 2797 patients without significant CAD underwent acetylcholine (Ach) provocation test between November 2004 and October 2010. Patients were divided into three groups, based on the presence of coronary artery spasm (CAS) and smoking habits (non-CAS group: n=1188, non-smoking CAS group: n=1214, smoking CAS group: n=395). All CAS patients were prescribed with anti-anginal medications for at least 6 months. The incidence of major clinical outcomes and recurrent angina of these groups were compared up to 3 years. Results: There were considerable differences in the baseline clinical and angiographic characteristics among the three groups, but there was no difference in the endpoints among the three groups (including individual and composite hard endpoints) such as death, myocardial infarction, de novo percutaneous coronary intervention, cerebrovascular accident, and major adverse cardiac events. However, there was a higher incidence of recurrent angina in both the non-smoking CAS group and smoking CAS group, as compared to the nonCAS group. In multivariable adjusted Cox-proportional hazards regression analysis, smoking CAS group exhibited a higher incidence of recurrent angina compared with the non-CAS group (hazard ratio [HR]; 2.46, 95% confidence interval [CI]; 1.46-4.14, p=0.001) and nonsmoking CAS group (HR; 1.76, 95% CI; 1.08-2.87, p=0.021). Conclusion: Cigarette smoking CAS group exhibited higher incidence of recurrent angina during the 3-year clinical follow-up compared with both the non-CAS group and non-smoking CAS group. Quitting of smoking, paired with intensive medical therapy and close clinical follow-up, can help to prevent recurrent angina.

Hepatitis B Prophylaxis after Liver Transplantation in Korea: Analysis of the KOTRY Database

Gil-Chun Park,Shin Hwang,김명수,Dong-Hwan Jung,Gi Won Song,Kwang-Woong Lee,Jong Man Kim,Jae Geun Lee,류제호,Dong Lak Choi,Hee-Jung Wang,Bong Wan Kim,Dong-Sik Kim,Yang Won Nah,Young Kyoung You,Koo Jeong Kang 대한의학회 2020 Journal of Korean medical science Vol.35 No.6

Background: Prophylaxis for hepatitis B virus (HBV) recurrence is essential after liver transplantation (LT) in HBV-associated recipients. We conducted real-world analysis of HBV prophylaxis after LT in the Korean population. Methods: Korean Organ Transplantation Registry (KOTRY) database and additionally collected data (n = 326) were analyzed with special reference to types of HBV prophylaxis. Results: The study cohort comprised 267 cases of living-donor LT and 59 cases of deceased-donor LT. Hepatocellular carcinoma (HCC) was diagnosed in 232 (71.2%) of these subjects. Antiviral agents were used in 255 patients (78.2%) prior to LT. HBV DNA was undetectable in 69 cases (21.2%) and detectable over wide concentrations in the other 257 patients (78.8%) prior to LT. Polymerase chain reaction analysis of the store blood samples detected HBV DNA in all patients, with 159 patients (48.9%) showing concentrations > 100 IU/mL. Post-transplant HBV regimens during the first year included combination therapy in 196 (60.1%), hepatitis B immunoglobulin (HBIG) monotherapy in 121 (37.1%), and antiviral monotherapy in 9 (2.8%). In the second post-transplant year, these regimens had changed to combination therapy in 187 (57.4%), HBIG monotherapy in 112 (34.4%), and antiviral monotherapy in 27 (8.3%). Trough antibody to hepatitis B surface antigen titers > 500 IU/mL and >1,000 IU/mL were observed in 61.7% and 25.2%, respectively. The mean simulative half-life of HBIG was 21.6 ± 4.3 days with a median 17.7 days. Up to 2-year follow-up period, HCC recurrence and HBV recurrence developed in 18 (5.5%) and 6 (1.8%), respectively. HCC recurrence developed in 3 of 6 patients with HBV recurrence. Conclusion: Combination therapy is the mainstay of HBV prophylaxis protocols in a majority of Korean LT centers, but HBIG was often administered excessively. Individualized optimization of HBIG treatments using SHL is necessary to adjust the HBIG infusion interval.

Improved Astaxanthin Availability due to Drying and Rupturing of the Red Yeast, Xanthophyllomyces dendrorhous

Gil-Hwan An,Jae-Yeon Song,Woong-Kwon Kwak,Bong-Duk Lee,Kyung-Bin Song,Jae-Eul Choi 한국식품과학회 2006 Food Science and Biotechnology Vol.15 No.4