One step bulk modification of poly(L-lactic acid) composites with functional additives to improve mechanical and biological properties for cardiovascular implant applications

Kang, Eun Young,Choi, Bogyu,Park, Wooram,Kim, Ik Hwan,Han, Dong Keun Elsevier 2019 Colloids and Surfaces B Vol.179 No.-

<P><B>Abstract</B></P> <P>Poly(L-lactic acid) (PLLA) has been widely used as a promising biomaterial in biomedical applications due to its biodegradability and high mechanical strength. However, because of the inherent brittleness, low impact resistance, and weak thermal stability of PLLA, the modification process is usually required to utilize it for biomedical devices. Furthermore, acidic byproducts resulting from the hydrolysis of PLLA after implantation reduce the pH of the surrounding environment and cause inflammatory responses in the implanted area, leading to the failure of their clinical applications. To this end, here, we demonstrate a novel modification process for the PLLA composite with various functional additives, such as cis-aconitic anhydride (AA), triacetin (TA), isosorbide derivative (ISB), and/or Pluronic® F127 (F). The modified PLLA composite with TA and F (PLLA/TF) showed significantly improved elongation at break and Young’s modulus and retained tensile strength. Moreover, incorporating magnesium hydroxide (MH) nanoparticles (PLLA/TFMH) significantly reduced acid-induced inflammation responses caused by the acidic degradation products of PLLA. Reduced plasma protein adsorption was observed in the PLLA/TFMH. These results suggest that the one step bulk modification of biodegradable PLLA using TA, F, and MH will have great potential in cardiovascular implant applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Improved mechanical properties of PLLA via one step bulk modification with TA and F. </LI> <LI> Reduced acid-induced inflammation via one step bulk modification of PLLA/TF with MH. </LI> <LI> Increased homogeneity of MH distribution in one step bulk modified PLLA/TFMH. </LI> <LI> Enhanced hemocompatibility of PLLA/TFMH. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

관상동맥질환 환자에서 스텐트 시술 후 재협착에 관한 연구

강진환,권영주,박상호,한대희,이상철,김명구,변정득,최병조,심규혁,온영근,현민수,김성구 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.2

Background and aims : In the coronary artery disease, a rate of restenosis was much decreased by placement of coronary stent than when percutaneous transluminal coronary angioplasty has been applied, but there are still important clinical problems of restenosis. There has been many progressive studies about various factors contributed to this restenosis. So, we studied a relation between restenosis after placement of coronary stent in the coronary artery disease and many clinical factors, characteristics of stenotic lesion and procedural factors, and also assessed the restenosis rate of various coronary stents. Methods : Total 58 lesions(46 cases of patients ; man 30, woman 16) were evaluated, which has been performed a follow-up coronary angiography after 6 months (mean 188 days) since coronary stent had been placed. Various stents were implanted and assessed a relation between restenosis and many factors. Results : Of 58 lesions were target stenotic studies, there were 22 of restenotic lesions(37.9%), and the restenosis rate wes statistically significant difference in the relation with diabetes mellitus(p<0.05), group of acute myocardial infarction(p<0.05) among clinical diagnosis of ischemic heart disease(stable angina, unstable angina and acute myocardial infarction) in clinical factors and with high dilation pressure of stent(p<0.05) in procedural factors. When the rate of restenosis was evaluated among implanted stents, it was lowest in the Multilink^(®) stent and highest in the Nir Royal^(®) stent(60%). Conclusion : In this study of restenosis and various factors after placement of stents in the coronary artety disease, factors such as diabetes mellitus, group of acute myocardial infarction and a dilation pressure of stent were significant related with restenosis and the restenosis rate of Multilink^(®) stent was lowest and the highest restenosis rate was of Nir Royal^(®) stent.

Centerless Feeder 장치의 개발

강형모,권경우,김기길,정의식,허영환 한밭대학교 산업과학기술연구소 1994 논문집 Vol.2 No.-

This paper presents results of the development of centerless feeding system which are applicable to bearing metal processes. As a result, the feeding system can be applied to automatic surface finishing on the bearing metal process such as bush, and has greatly effects on the increase of the prodnctiving and the decrease of the man power an effect on increase the productivity and decrease the man power and effect on increase the productivity and decrease the man power of the bush machining process.

우리 나라에서 재해방지를 위한 개선안 생활변화단위 모형 개발 및 응용

강영식,함효준,양성환 대한설비관리학회 2003 대한설비관리학회지 Vol.8 No.2

The major cause of the industrial accidents is often induced by the human error. It brings about all kind of accidents. Moreover, the more the information and system complicates, the more the human error brings about. So the active accident prevention policy by human behavior, life style, culture, and psychology should develop at this time. Especially, the behavior models have provided the accident proneness concept through the life change unit factors. According to the existing studies on the life change unit models, the oriental behavior models differs from the western model in the life style and ideas. Therefore, the purpose of this paper is to develop the proposed life change unit model by the improved life change unit factors, and to evaluate its application in real fields. The proposed model can be simply applied in real fields in order to minimize the industrial accidents

영산호의 수질오염에 관한 조사연구

강영식,김병환 광주보건대학 1992 論文集 Vol.17 No.-

Water quality of Youngan Lake was Examined for 6months 6months from Jun 30, 1990 to Nov, 1990. For checking the water quality 9 sampling positions were selected. The results we obtained are as follow. 1. The average for Yongsan Lake was 6.6 ∼ 8.3 of pH, 22.0 ∼ 23 of water temp. 1.4 ∼ 8.2 ㎎/㎣ of chlorophy1-a, 44.0 ∼ 345.2 ㎎/1 of C1^(-). 2. The phytoplanton identification in this survey period showed cyanophyceae 11 genera 14 species, Bacillariophyceae 27 genera 72 species and chlorophyceae 16 genera 29 species ; Total 54 genera 115 species. 3. To appear dominat algea there were Anabeana sp. Anacystis aeruginosa, Lyngbya contorta, Actinastrum hantzschii dar, fluviatile, Dictyosphaerium pulchellum, Melosira granulta, M. granulata var. angustissima.

24주간 추적하는 임상 연구에서 한국인 남자 알코올 의존 환자의 비재발률

강철중,김성곤,남궁기,조동환,이병욱,최인근,최용성,박성봉,제영묘,김현경,김성연 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.1

Objetives : In order to provide useful data tbr the further clinical studies with Korean alcohol-dependent patients, enrollment and non-relapse rates were investigated while alcohol-dependent patients wcre followed up for 24 weeks. Methods : The subjects of this study were alcohol-dependent male patients who, for the first time, visited a hospital among 3 groups of hospitals, University Hospital, General Hospital or Mental Hospital, or those who needed to be followed up after discharge from those hospitals. After assigning 12 subjects to each hospital, we investigated enrollment and non-relapse rates while cognitive-behavioral therapy and pharmacotherapy were provided. Results : 1) Forty-eight patients were enrolled and the rate of enrollment was 36.4%. The enrollment rate in the University Hospital group was 52.1%, in the General Hospital group 50.0%. and in the Mental Hospital group 10.4%. 2) In 48 patients, non-relapse rate was 27.1% at 12 week and 18.8% at 24 weeks after starting follow-up. It was 24.4% and 20.0% at 12 and 24 weeks, repectively, in the University Hospital group while the General Hospital group showed 33.3% and 16.7%, respectively, and the Mental Hospital Group showed 20.0% at both 12 and 24 weeks. Conclusion : These results provide important data for further clinical studies of Korean alcohol-dependent patients.

Trioctylamine에 의한 유기산의 추출

강안수,이병철,이한섭,안형환,이영주,류운형 明知大學校 産業技術硏究所 1993 産業技術硏究所論文集 Vol.12 No.-

For elucidation of various parameter's effect on the reactive extraction of organic acidstrioctylamine(TOA)-diluents system, the association model, equilibrium constants and extraction factors(loading) were investigated . The organic acids rosed were propionic. succinic, masonic, and benzoic acid. Extractant was tertiary amine, TOA and diluents were butylaeohol, hexane, and benzene. It was concluded that the loading of monobasic acid of propionic acid were higher than that of dibasic acids of oxalic, and malonic acid with extranctant TOA. In the extraction of monobasic acid the extraction factor was not affected by the initial concentration of extractant amine, but in the extraction of dibasic acids the extraction factor was getting better with decreasing the initial concentration of amine. There was a strong effect of diluents upon the extractien factor, and the order of these factor was as shown below: xylene<Benzene<butylalcohol<choloroform<methylisobutylketone.

두경부 종양세포주에 대한 Mithramycin A의 세포자멸사 유도성 및Cisplatin 항암작용 증가효과

이강대,손성환,박종욱,김영록,이봉주,김주연 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.1

Background and Objectives : Cisplatin (CP) is a major chemotherapeutic agent for head and neck cancer. However, cancer cells can get drug resistance through recovering the DNA damage by CP. Mithramycin A (MA) can inhibit gene expression of multidrug resistance gene 1, c-myc or h-ras. The goal of this study is to evaluate the therapeutic effect of MA alone and combination of MA and CP on head and neck cancer cell lines. Materials and Methods : Two head and neck cancer cell lines (AMC-HN4, AMC-HN7) were treated with MA. The cellular proliferation, apoptosis and protein expression were measured with XTT assay, FACS analysis, and western blotting, respectively after MA treatment in cell lines. In order to know the combination effect of MA with CP, the cancer cell lines were treated with MA, CP, and MA/CP combination, and cellular proliferation, apoptosis and expression of apoptosis-associated proteins were measured. Results : MA inhibited the proliferation of head and neck cancer cells and induce dapoptosis. Increase of caspase activation, PLC-?1 fragmentation and percent apoptosis by MA treatment was blocked by z-VAD-fms, but not blocked by N-Acetyl Cystein. Combination of MA and CP significantly inhibited cancer cell growth and increased apoptosis compared to MA and CP alone, and it also suppressed the expression of anti-apoptotic proteins such as XIAP and Mcl-1. Conclusions : The present study suggests that MA alone andMA/CP combination chemotherapy could be a potential regiment for the control of the head and neck cancer.

특징 영역 기반의 칼라 얼굴 영상 인식

강영미,정성환 國立 昌原大學校 精報通信硏究所 1998 精報通信論文集 Vol.2 No.-

In this paper, a face recognition system is proposed, which extracts the feature region in a color face image an recognizes a face using neural net. First, we transform RGB color model into HSI and seek a facial region by hue component range. Next, using Wavelet transform, we remove unnecessary details and extract a feature region. Finally, we recognize the face of an extracted feature region using ART2 neural net. The proposed method does not require individual feature extraction because a feature region preserves its detailed information for each face. It can also process the information in Wavelet transform domain. Therefore, the proposed method can extract features efficiently in large image databases. In the experiment with 150 facial images, the proposed method shows about 93% recognition rate.