Study on the Elastic Characteristics of Living Cells using Atomic Force Microscope Indentation Technique

Kwon Eun-Young,Kim Young-Tae,Kim Dae-Eun Korean Tribology Society 2006 KSTLE International Journal Vol.7 No.1

In this work, imaging and study of elastic property of the living cell was performed. The motivation of this work was to seek the possibility of exploiting Young's modulus as a disease indicator using Atomic Force Microscope (AFM) and also to gain fundamental understanding of cell mechanics for applications in medical nanorobots of the future. L-929 fibroblast adherent cell was used as the sample. Imaging condition in cell culturing media environment was done in very low speed ($20{\mu}m/ s$) compared to that in the ambient environment. For measuring the Young's modulus of the living cell, AFM indentation method was used. From the force-distance curve obtained from the indentation experiment the Young's modulus could be derived using the Hertz model. The Young's modulus of living L-929 fibroblast cell was $1.29{\pm}0.2$ kPa.

Study on the Elastic Characteristics of Living Cells using Atomic Force Microscope Indentation Technique

Eun-Young Kwon,Young-Tae Kim,Dae-Eun Kim 한국트라이볼로지학회 2006 KSTLE International Journal Vol.7 No.1

In this work, imaging and study of elastic property of the living cell was performed. The motivation of this work was to seek the possibility of exploiting Young’s modulus as a disease indicator using Atomic Force Microscope (AFM) and also to gain fundamental understanding of cell mechanics for applications in medical nanorobots of the future. L-929 fibroblast adherent cell was used as the sample. Imaging condition in cell culturing media environment was done in very low speed (20 μm/s) compared to that in the ambient environment. For measuring the Young’s modulus of the living cell, AFM indentation method was used. From the force-distance curve obtained from the indentation experiment the Young’s modulus could be derived using the Hertz model. The Young’s modulus of living L-929 fibroblast cell was 1.29 ± 0.2 kPa.

AFM indentation 기법을 이용한 세포의 탄성특성에 관한 연구

권은영(Eun-Young Kwon),김영태(Young-Tae Kim),김대은(Dae-Eun Kim) 한국트라이볼로지학회 2006 한국트라이볼로지학회 학술대회 Vol.2006 No.6

In this work, imaging and investigation of elastic property of the living cell was performed. The motivation of this work was to seek the possibility of exploiting Young's modulus as a disease indicator using Atomic Force Microscope (AFM) and also to gain fundamental understanding of cell mechanics for applications in medical nanorobots of the future. L-929 fibroblast adherent cell was used as the sample. Imaging condition in cell culturing media environment was done in very low speed(20 ㎛/s) compare to that in ambient environment. For measuring the Young's modulus of the living cell, AFM indentation method was used. From the force-distance curve obtained from the indentation experiment the Young's modulus could be derived using the Hertz model. The Young's modulus of living L-929 fibroblast cell was 1.29 ± 0.2 kPa.

젊은 성인에서 흡연에 의한 상완동맥 내피기능의 부전에 관한 연구

이상철,권영주,방덕원,이선해,이보영,김지욱,김영훈,온영근,현민수,김성구 순천향의학연구소 2002 Journal of Soonchunhyang Medical Science Vol.8 No.1

Background and Objectives : Cigarette smoking is a major factor and the most modifiable risk factor for atherosclerosis. Endothelial dysfunction is an early event in atherosclerosis, before the structural change of the systemic arteries. We hypothesized that endothelial dysfunction might be present in the systemic arteries of young adult smokers and that this might be dose-dependent phenomenon. Therefore, we try to certify that smoking is associated with endothelial dysfunction in healthy young adults without other risk factor of atherosclerosis. Subjects and Methods : we studied noninvasively 29 subjects aged 3 to 4 decades without other risk factor of atherosclerosis, they were composed of the two groups, current smokers(n=15) and nonsmokers(n=14). Smoking history varied from 3 to 20 pack years. Using high-resolution ultrasound, vessel diameter and mean flow rate were measured at rest, during reactive hyperemia(with flow-mediated endothelium-dependent dilation), and after sublingual nitroglycerin(NG-induced endothelium-independent vasodilation). Result : Flow mediated endothelium dependent dilation was observed in the control subjects (9.4±3.44%) but was impaired in the smokers(5.8±2.51%)(p=0.004). NG-induced endothelium independent dilation is no difference in all subjects. Conclusion : Cigarette smoking is associated with endothelial dysfunction in healthy young adults.

Comparison of trophic factors changes in the hippocampal CA1 region between the young and adult gerbil induced by transient cerebral ischemia.

Yan, Bing Chun,Park, Joon Ha,Kim, Sung Koo,Choi, Jung Hoon,Lee, Choong Hyun,Yoo, Ki-Yeon,Kwon, Young-Geun,Kim, Young-Myeong,Kim, Jong-Dai,Won, Moo-Ho Kluwer Academic/Plenum Publishers 2012 Cellular and molecular neurobiology Vol.32 No.8

<P>In the present study, we investigated neuronal death/damage in the gerbil hippocampal CA1 region (CA1) and compared changes in some trophic factors, such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF), in the CA1 between the adult and young gerbils after 5 min of transient cerebral ischemia. Most of pyramidal neurons (89%) were damaged 4 days after ischemia-reperfusion (I-R) in the adult; however, in the young, about 59% of pyramidal neurons were damaged 7 days after I-R. The immunoreactivity and levels of BDNF and VEGF, not GDNF, in the CA1 of the normal young were lower than those in the normal adult. Four days after I-R in the adult group, the immunoreactivity and levels of BDNF and VEGF were distinctively decreased, and the immunoreactivity and level of GDNF were increased. However, in the young group, all of their immunoreactivities and levels were much higher than those in the normal young group. From 7 days after I-R, all the immunoreactivities and levels were apparently decreased compared to those of the normal adult and young. In brief, we confirmed our recent finding: more delayed and less neuronal death occurred in the young following I-R, and we newly found that the immunoreactivities of trophic factors, such as BDNF, GDNF, and VEGF, in the stratum pyramidale of the CA1 in the young gerbil were much higher than those in the adult gerbil 4 days after transient cerebral ischemia.</P>

Preparation and Characterization of Surface Energy of BPDA-BAPP Polyimide

Kim, Kyung-Hoe,Kim, Yong-Gwon,Kwon, Young-Hwan The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.6

The surface properties (water sorption and repellency, adhesion) are closely related to the surface tension of polymer solids. The critical surface tension (${\gamma}_c$) and surface tension (${\gamma}_s$) of a polymer solid were estimated by the contact angle method by our quantitative imaging system. BPDA (3,3',4,4'-biphenyl tetracarboxylic dianhydride)-BAPP (1,3-Bis(4-aminophenoxy) propane) polyimide was successfully synthesized. The ${\gamma}_c$ values were analyzed by a Zisman plot, a Young-$Dupr\acute{e}$-Good-Girifalco plot, and a log ($1+cos{\theta}$) vs log ${\gamma}_L$ plot. The ${\gamma}_s$ value of BPDA-BAPE polyimide was evaluated using the geometric mean equation and our multiple regression analysis. The calculated values of ${{\gamma}_s^d$ (a dispersion component), ${{\gamma}_s^p$ (a polar component), ${{\gamma}_s^h$ (a hydrogen bonding component), and ${\gamma}_s$ were 30.79, 9.32, 0.20, and 40.31 $mN{\cdot}m^{-1}$, respectively. The ${\gamma}_s$ of BPDA-BAPP polyimide containing both a methylene group and an ether group was larger than that of the polyimide containing only a methylene group.

정신분열병 환자의 가족부담 척도 개발에 대한 예비연구

김철권,조진석,서지민,김용관,김호찬,김현수,김상수,제영묘 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.3

연구목적 : 정신분열병 환자의 가족이 느끼는 부담을 측정하기 위한 가족부담 척도를 개발하기 위함이다. 방 법 : 200명의 정신분열병 환자 가족과의 비구조적 면담과 외국 부담척도 고찰을 통하여 94문항을 수집하였고 그 다음에 전문가들과 가족들이 문항 및 영역을 분류하고 통합하여 최종적으로 36문항을 선정하였다. 그리고 정신분열병 환자의 가족 135명, 불안장애 환자의 가족 22명, 기분부전장애 및 신체화 장애 환자의 가족 26명, 치매 환자의 가족 49명을 대상으로 신뢰도와 타당도를 검증하였다. 결 과 : 자료분석 결과 검사-재검사 신뢰도, 내적 일치도, 감별타당도 모두 높게 나타났으며, 요인분석을 통해 다섯 가지 구성요인이 추출되었다. 결 론 : 본 가족부담 척도는 정신분열병을 포함한 만성 정신질환을 앓고 있는 환자의 호전과 가족의 부담을 덜어주기 위한 다양한 프로그램의 효과를 검증하는데 유용하게 사용되어질 수 있을 것이다. Objectives : This preliminary study was carried out to develop the Family Burden Scale(FBS) of the schizophrenics. Methods : Ninety-four items were collected by interviewing in a free unstructured format with one relative of each 200 schizophrenic patients and reviewing foreign FBS's. Several professionals and relatives were asked to group and integrate them into several categories. Finally 36 burden items were chosen to constitute a FBS. The FBS was administered to the relatives of 135 schizophrenic, 22 anxiety disorder, 26 dysthymic disorder and somatization disorder, and 49 dementia patients for examining the reliability and validity. Results : The FBS showed high test-retest reliability, internal consistency, and discriminant validity. The results of the factor analysis revealed five-factor solution. Conclusion : The FBS can be used to evaluate the effectiveness of various programs intended not only to reduce decompensation among schizophrenics, but also to alleviate family burden.

전방 불안정성 견관절에서 이두박근의 근전도 활동성

김승호,하권익,김현숙,김선우,박종혁,김영민 대한견.주관절학회 2000 大韓肩.주關節學會誌 Vol.3 No.2

정신과 입원환자의 서비스 만족척도의 개발

김철권,이지연,송영선,김규호,김경률,김제원,이동기,최병무 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.3

목적 본 연구의 목적은 국내 정신의료기관(정신병원, 종합병원 정신과)에서 간편하게 사용할 수 있는 신뢰도와 타당도가 검증된 입원환자의 서비스 만족척도를 개발하기 위한 것이다. 방법 여러 단계를 거쳐 국내 실정에 맞는 문항을 개발하였고,정신병원, 종합병원, 대학병원 정신과 병동에서 퇴원하는 348명의 환자들을 대상으로 신뢰도와 타당도를 조사하였다. 요인분석 결과 5개의 요인이 추출되었으며 전체 변량의 63.04%를 설명하였다. 내적 일관성에 대한 신뢰도 계수 (Crohnbach's α)는 0.95로 상당히 높은 수준이었고, 수정된 개별문항-총점 상관계수는 0.50부터 0.72까지의 범위에 속하였다. 요인분석을 통해 추출된 서비스 만족척도의 각 하위척도 점수와 서비스 만족척도에 첨부된 각 영역에 대해 전반적인 만족도를 묻는 세 개의 문항 점수 간의 상관성 역시 유의하게 높았다. 결과 진단명에 따른 서비스 만족척도의 전체 점수에서는 불안/신체형/강박장애 환자군과 기분장애 환자군이 각각 정신분열병 및 기타 정신병 환자군과 알코올중독 장애 환자군에 비하여 유의하게 높은 점수를 보였으며, 입원형태에 있어서는 자발적 입원군이 강제 입원군에 비하여 전체 만족점수가 유의하게 높았다. 그러나 성별, 월수입, 학력, 직업, 종교, 결혼상태 등의 변수에서는 서비스 만족척도의 전체 점수에서 유의한 차이가 발견되지 않았으며, 마찬가지로 연령, 입원일수, 입원횟수, 첫 발병나이, 유병기간 등의 임상적 변수에서도 서비스 만족척도의 전체 점수와 유의한 관계를 보이지 않았다. 서비스 만족척도의 전체점수에서 대학병원 환자군이 정신병원 환자군과 종합병원 환자군에 비하여 각각 유의하게 높았다. 결론 결론적으로 국내 정신의료기관에 입원한 환자들의 서비스 만족을 평가하기 위한 목적으로 개발된 본 척도는 높은 수준의 신뢰도와 타당도를 보였으며, 또 국내 정신의료 환경에 맞는 요인구조를 보였다. 따라서 정신의료 서비스에 대한 정신과 환자의 만족도에 대한 연구가 거의 없는 실정에서 본 척도의 개발은 향후 국내 정신의료의 질과 치료결과를 높이는 도구로 활용될 수 있을 것으로 기대된다. Objectives : To develop and test the validity and reliability of a brief self-completed questionnaire (Service Satisfaction Scale : SSS) for routinely assessing the quality of service in psychiatric ward inpatients. Methods : A 30-item multidimensional questionnaire was developed by several steps of face validity and content validity. The questionnaire was administered to inpatients (n=348) discharged from psychiatric hospitals, general hospitals, and University hospitals. Construct validity was supported by performing principal component analysis. Reliability was estimated by calculating internal consistency of Cronbach's alpha. Results : Factor analysis yielded five factors comprising staff attitude, treatment quality, ward environment, access/cost, and ward rule, which account for 63.04% of the common variance. The internal consistency of the scale was high (Cronbach's alpha=0.95). The concurrent validity was supported by the significant correlation of each of five factors with item that measured overall satisfaction of SSS. Patients with neurosis (anxiety disorder, somatoform disorder, obsessive compulsive disorder) and mood disorders were significantly satisfied than those with psychosis and alcoholic disorders. Patients who admitted voluntarily were more significantly satisfied than those who admitted involuntarily. Sociodemographic variables such as age, gender, marital status, monthly income, education level, employment status and religion were not significantly different at the total scores of SSS. Similarly, clinical characteristics such as age of onset, duration of illness, lengths of hospital stay and number of previous hospitalization did not associate significantly with the total scores of SSS. Patients discharged from university hospitals were significantly more satisfied than those of the general and psychiatric hospitals. Conclusion : SSS performed well in the validity and reliability, indicating that it can be a useful tool for measuring Satisfaction of psychiatric inpatients in Korea.

Identification of a sensitive urinary biomarker, selenium-binding protein 1, for early detection of acute kidney injury

Kim, Kyeong Seok,Yang, Hun Yong,Song, Hosup,Kang, Ye Rim,Kwon, JiHoon,An, JiHye,Son, Ji Yeon,Kwack, Seung Jun,Kim, Young-Mi,Bae, Ok-Nam,Ahn, Mee-Young,Lee, Jaewon,Yoon, Sungpil,Lee, Byung μ,Kim, Hyung TAYLOR & FRANCIS 2017 Journal of Toxicology and Environmental Health Vol.80 No.9

<P>Acute kidney injury (AKI) is associated with increased mortality rate in patients but clinically available biomarkers for disease detection are currently not available. Recently, a new biomarker, selenium-binding protein 1 (SBP1), was identified for detection of nephrotoxicity using proteomic analysis. The aim of this study was to assess the sensitivity of urinary SBP1 levels as an early detection of AKI using animal models such as cisplatin or ischemia/reperfusion (I/R). Sprague-Dawley rats were injected with cisplatin (6 mg/kg, once i.p.) and sacrificed at 1, 3, or 5 days after treatment. Ischemia was achieved by bilaterally occluding both kidneys with a microvascular clamp for 45 min and verified visually by a change in tissue color. After post-reperfusion, urine samples were collected at 9, 24, and 48 hr intervals. Urinary excretion of protein-based biomarkers was measured by Western blot analysis. In cisplatin-treated rats, mild histopathologic alterations were noted at day 1 which became severe at day 3. Blood urea nitrogen (BUN) and serum creatinine (SCr) levels were significantly increased at day 3. Levels of urinary excretion of SBP1, neutrophil gelatinase-associated lipocalin (NGAL), and a tissue inhibitor of metalloproteinase-1 (TIMP-1) were markedly elevated at day 3 and 5 following drug treatment. In the vehicle-treated I/R group, serum levels of BUN and SCr and AST activity were significantly increased compared to sham. Urinary excretion of SBP1 and NGAL rose markedly following I/R. The urinary levels of SBP1, NGAL, TIMP-1, and KIM-1 proteins excreted by AKI patients and normal subjects were compared. Among these proteins, a marked rise in SBP1 was observed in urine of patients with AKI compared to normal subjects. Based upon receiver-operator curves (ROC), SBP1 displayed a higher area under the curve (AUC) scores than levels of SCr, BUN, total protein, and glucose. In particular, SBP1 protein was readily detected in small amounts of urine without purification. Data thus indicate that urinary excretion of SBP1 may be useful as a reliable biomarker for early diagnosis of AKI in patients.</P>