• 제목/요약/키워드: Screening system

검색결과 1,401건 처리시간 0.028초

Screening Methods for Anti-senescence Activity in Dermal Fibroblasts under Pyruvate-deprivation Conditions

  • Kil, In Sup;Shim, Jinsup;Cho, Gayoung;Choi, Sowoong;Son, Eui Dong;Kim, Hyoung-June
    • Korea Journal of Cosmetic Science
    • /
    • 제1권1호
    • /
    • pp.1-9
    • /
    • 2019
  • The identification of compounds with anti-senescence activity in cell culture system is a first step in aging research. Given that pyruvate can be used energy source by conversion to acetyl-CoA in mitochondria, and protects cultured cell from various stress-induced cell damage and cell death, synthetic media (e.g., DMEM) often includes 1 mM pyruvate, which is very higher than the pyruvate concentration in human blood (approximately 30 ��M). However, the use of medium containing high concentration of pyruvate is not suitable for screening anti-senescence compounds, because pyruvate also protects against the cellular senescence of primary human dermal fibroblasts (NHDFs) through NAD+ generated during conversion to lactate. In this study, four extracts, i.e., Sprouted seed and fruit complex, Poncirus trifoliata fruit extract, Jaum balancing complex, and Prunus mume extract were used for evaluation of different anti-senescence effect in the absence or presence of 0.1 mM pyruvate, similar to the physiological pyruvate concentration. The senescence in NHDFs cultured with DMEM in the presence of 0.1 mM pyruvate (approximately the physiological concentration in human blood) is accelerated, as observed in pyruvate deprivation conditions. The cytotoxicity of the Poncirus trifoliata fruit extract was protected by pyruvate, and Jaum balancing complex and Prunus mume extract had anti-senescence activity in the presence of 0.1 mM pyruvate, but not in the absence of pyruvate. Given that pyruvate is a powerful protector against both cytotoxicity and cellular senescence, the screening of candidate agents for anti-senescence in high pyruvate conditions using an in vitro cell culture system is not valid. Therefore, we recommend the use of a low concentration of pyruvate to evaluate the anti-senescence effects of candidates, which is more similar to in vivo aging conditions than excessive stress-induced senescence models, to exclude the effect of excessive pyruvate in vitro.

Influence of Device Parameters Spread on Current Distribution of Paralleled Silicon Carbide MOSFETs

  • Ke, Junji;Zhao, Zhibin;Sun, Peng;Huang, Huazhen;Abuogo, James;Cui, Xiang
    • Journal of Power Electronics
    • /
    • 제19권4호
    • /
    • pp.1054-1067
    • /
    • 2019
  • This paper systematically investigates the influence of device parameters spread on the current distribution of paralleled silicon carbide (SiC) MOSFETs. First, a variation coefficient is introduced and used as the evaluating norm for the parameters spread. Then a sample of 30 SiC MOSFET devices from the same batch of a well-known company is selected and tested under the same conditions as those on datasheet. It is found that there is big difference among parameters spread. Furthermore, comprehensive theoretical and simulation analyses are carried out to study the sensitivity of the current imbalance to variations of the device parameters. Based on the concept of the control variable method, the influence of each device parameter on the steady-state and transient current distributions of paralleled SiC MOSFETs are verified separately by experiments. Finally, some screening suggestions of devices or chips before parallel-connection are provided in terms of different applications and different driver configurations.

부인암을 가진 여성에서 유방암의 선별검사로서의 디지털 유방단층 촬영술 (Digital Breast Tomosynthesis as a Breast Cancer Screening Tool for Women with Gynecologic Cancer)

  • 김다훈;정진;차은숙;이지은;김정현
    • 대한영상의학회지
    • /
    • 제81권4호
    • /
    • pp.886-898
    • /
    • 2020
  • 목적 본 연구는 부인암을 가진 여성에서 유방암의 선별검사로서의 디지털 유방단층 촬영술을 평가하였다. 대상과 방법 부인암을 가진 환자들 중 검진 목적으로 디지털 유방단층 촬영술을 촬영한 환자들을 대상으로 후향적 연구를 시행하였으며 유방암 발견율, 소환율, 민감도, 특이도, 양성예측도를 계산하였다. 양성예측도 1은 모든 양성 선별검사 중 1년 이내에 조직 검사에서 유방암을 진단받은 환자의 백분율로 정의되었다. 양성예측도 2는 진단 검사에서 조직검사의 필요 판정을 받은 후(그리고 선별 검사에서 Breast Imaging Reporting and Data System 카테고리 4, 5를 받은 후) 1년 이내에 조직검사에서 유방암을 진단받은 환자의 백분율로 정의되었다. 양성예측도 3은 실제로 조직검사를 시행 받은 환자 중 1년 이내에 조직검사에서 유방암을 진단받은 환자의 백분율로 정의되었다. 검진으로 발견된 암의 각 경우에 대해 환자의 나이, 부인암의 종류, 유방 밀도, 영상의 특징, 최종 Breast Imaging Reporting and Data System 평가, 조직학적 유형, T 및 N 병기, 분자아형 및 Ki-67 지수를 분석했다. 결과 전체 508명 중 7개의 유방암이 발견되었으며 유방암 발견율은 1000건 당 암 13.8이었다. 민감도는 100%, 특이도는 83.2%였으며 위음성률은 1000건 당 0이었다. 양성예측도 1, 양성예측도 2, 양성예측도 3은 각각 7.7, 31.8, 31.8이었으며 소환율은 17.9%였다. 결론 본 연구에서 디지털 유방단층 촬영술은 높은 유방암 발견율, 높은 민감도, 높은 양성예측도를 보이며 T, N 병기가 낮은 초기 암에 대해 높은 발견율을 보였다. 따라서 부인암 환자와 같은 고위험군에서 유방암의 선별검사로서 디지털 유방단층 촬영술이 유용할 수 있다.

영세사업장 보건관리 지원사업 실시 전후의 산업보건수준 비교 분석 (A Comparative Analysis of the Level of Occupational Health : Before and After the Subsidiary Program on Health Care Management of Small Scale Industries)

  • 정혜선
    • 한국직업건강간호학회지
    • /
    • 제4권호
    • /
    • pp.58-83
    • /
    • 1995
  • The small scale industries which have less than 30 employees occupy 86.5% of total number of industries in Korea. And though they have higher accident rate and lower environmental condition than big industries, it has been not mandatory to appointing health care manager at factory. So, from 1993, government subsidizes to the health care management of small industries. The purpose of this study is to identify the real feature of health care status in small industries, and to evaluate the level of health care management, before and after the subsidiary program. 65 small plating industries which have been managed by the same health care management support institution in 1993 were selected for study. Of the 65 industries, 3 which have not taken both environmental evaluation and health screening in 1994, and 9 which have closed were excluded from study sample. And the remaining 53 were analyzed by using the results of environmental evaluation and health screening, reported to the Ministry of Labor, before and after the subsidiary program, the analysis was done by the comparison of the two year paired data of the same industry. Over-permissible-limit rate, health screening implementation rate, above grade C rate were calculated and compared. The status of health care management ; 1. Of the sample industries, 96.9% provide protective equipment and 80.0% set up ventilating system. Protective gloves (89.2%) and protective clothing (80.0%) are widely provided, but ear plugs (4.6%) are rarely provided. 21.5% of the protective equipment are well put on, and 40.4% of the ventilating systems function well. 2. In 1993, 35 industries, 53.8% of the sample, checked working environment twice. Over-permissible-limit rates of heavy metal (12.2%), suspended particle (11.1%), noise (5.5%) were high. To put on protective equipment and to set up local ventilating system were pointed out by the examiners. 3. General health screening was done at 63.1% of the sample industries and 35.3% of total workers were examined. Specific health screening was done at 93.8% of the sample industries and 75.4% of workers were examined. 15.5% of workers was provided to be above grade C and to have digestive system disease (43.3%), circulatory disease (18.9%), and hematopoietic disease (14.2%), etc. 4. In 1993, the subsidiary program of health care management was provided in forms of health education, health counseling, and rounding check of working field. And 61.5%, 83.0%, 55.4% of sample industries respectively received it. The average visit per industry was 1.8. Comparisons of the level of occupational health before and after the subsidiary program ; 1. Over-permissible-limit rates of hazardous factors of 1993 and that of 1994 were compared. The rates of suspended particle, noise, organic solvent of 1994 (37.5%, 13.4%, 24.2% respectively) were higher than that of 1993 (25.0%, 6.0%, 6.3% respectively). In the case of acid, there was no difference between the rate of 1993 and that of 1994. Only the rate of heavy metal decreased from 12.9% in 1993 to 3.0% in 1994. 2. General health screening was done at 38.7% of the sample industries in 1993 and at 44.6% in 1994. But the implementation rate of specific health screening decreased from 72.4% in 1993 to 64.6% in 1994. 3. The implementation rate of specific health screening was analyzed by some health factors. The rate of suspended particle increased from 61.8% in 1993 to 91.2% in 1994. But the rates of the others-noise, organic solvent, heavy metal, specific chemical substances-decreased. 4. Above grade C rate in health screening increased from 27.8% in 1993 to 35.5% in 1994. But that of endocrine disorders and pulmonary disease decreased.

  • PDF

당뇨병 환자의 당뇨성 안질환 및 신장질환 합병증 검사 수검 여부에 영향을 주는 요인 (Factors affecting Diabetic Eye disease and Kidney disease Screening in Diabetic Patients)

  • 강정희
    • 한국산학기술학회논문지
    • /
    • 제21권4호
    • /
    • pp.226-235
    • /
    • 2020
  • 연구목적은 당뇨성 안질환 및 신장질환 합병증 검사 수검여부에 영향을 주는 요인을 알아보기 위함이다. 본 연구는 2017년 지역사회 건강조사 전국 자료를 이용하였으며, 연구대상은 의사에게 당뇨병을 진단받은 적이 있다고 응답한 사람 25,829명이다. 당뇨병 환자의 당뇨성 안질환 및 신장질환 합병증 검사 수검여부에 영향을 주는 요인을 알아보기 위해 로지스틱 회귀분석을 실시하였다. 연구결과는 당뇨병 환자 중 당뇨성 안질환 합병증 검사 수검율은 35.6%, 당뇨성 신장질환 합병증 검사 수검률은 39.8%이었다. 걷기실천을 할수록(OR=1.03, OR=1.02), 당화혈색소(OR=2.33, OR=2.33) 및 혈당수치(OR=1.61, OR=1.71)를 인지하는 사람과 현재 당뇨병 치료(OR=2.67, OR=3.05) 및 당뇨병 관리교육(OR=1.45, OR=1.47)을 받는 사람의 당뇨성 안질환 및 신장질환 합병증 검사를 받을 가능성이 많았다. 결론적으로 당뇨성 합병증 검사 수검율을 높이기 위해서는 당뇨병 환자를 대상으로 당뇨성 합병증 검사의 종류와 검사 시기가 포함된 당뇨병 관리 교육체계와 당화혈색소 및 혈당수치를 인지시킬 수 있는 다양한 홍보 방법 등이 개발되어야 할 것으로 생각된다. 그리고 당뇨병 관리를 위한 가이드라인 개발하고, 국가차원에서 국가검진제도에 당뇨성 합병증 검사 선별검사항목을 포함하는 등 시스템이 필요할 것으로 보인다.

Modern diagnostic capabilities of neonatal screening for primary immunodeficiencies in newborns

  • Khalturina, Evgenia Olegovna;Degtyareva, Natalia Dmitrievna;Bairashevskaia, Anastasiia Vasi'evna;Mulenkova, Alena Valerievna;Degtyareva, Anna Vladimirovna
    • Clinical and Experimental Pediatrics
    • /
    • 제64권10호
    • /
    • pp.504-510
    • /
    • 2021
  • Population screening of newborns is an extremely important and informative diagnostic approach that allows early identification of babies who are predisposed to the development of a number of serious diseases. Some of these diseases are known and have effective treatment methods. Neonatal screening enables the early diagnosis and subsequent timely initiation of therapy. This helps to prevent serious complications and reduce the percentage of disability and deaths among newborns and young children. Primary immunodeficiency diseases and primary immunodeficiency syndrome (PIDS) are a heterogeneous group of diseases and conditions based on impaired immune system function associated with developmental defects and characterized by various combinations of recurrent infections, development of autoimmune and lymphoproliferative syndromes (genetic defects in apoptosis, gene mutation Fas receptor or ligand), granulomatous process, and malignant neoplasms. Most of these diseases manifest in infancy and lead to serious illness, disability, and high mortality rates. Until recently, it was impossible to identify children with PIDS before the onset of the first clinical symptoms, which are usually accompanied by complications in the form of severe coinfections of a viral-bacterial-fungal etiology. Modern advances in medical laboratory technology have allowed the identification of children with severe PIDS, manifested by T- and/or B-cell lymphopenia and other disorders of the immune system. This review discusses the main existing strategies and directions used in PIDS screening programs for newborns, including approaches to screening based on excision of T-cell receptors and kappa-recombination excision circles, as well as the potential role and place of next-generation sequencing technology to increase the diagnostic accuracy of these diseases.

Establishment of a Binding Assay System for Screening of the Inhibitors of $p56^{lck}$ SH2 Domain

  • Kim, Jyn-Ho;Hur, Eun-Mi;Yun, Yung-Dae
    • BMB Reports
    • /
    • 제31권4호
    • /
    • pp.370-376
    • /
    • 1998
  • Src-Homology 2 (SH2) domains have a capacity to bind phosphotyrosine-containing sequence context and play essential roles in various cellular signaling pathways. Due to the specific nature of the binding between SH2 domains and their counterpart proteins, inhibitors of SID domain binding have drawn extensive attention as a potential candidate for therapeutic agents. Here, we describe the binding assay system to screen for the ligands or blockers of the SH2 domains with an emphasis on the $p56^{lck}$ SH2 domain. In our assay system, SID domains expressed and purified as fusion proteins to Glutathione-S-transferase (GST) were covalently attached to 96-well microtitre plates through amide bond formation, which were subsequently allowed to bind the biotinylated phosphotyrosine (pY)containing synthetic pep tides. The binding of biotinylated pY peptides was detected by the horseradish peroxidase (HRP)-conjugated streptavidin. Using the various combinations of SH2 domain-pY peptides, we observed that: (1) The binding of pY-peptides to its counterpart SH2 domain is concentration-dependent and saturable; (2) The binding is highly specific for a particular combination of SH2 domain-pY peptide pair; and (3) The binding of Lck SH2-cognate pY-peptides is specifically competed by the nonbiotinylated peptides with expected relative affinity. These results indicate that the established assay system detects the SH2-pY peptide interaction with reproducible sensitivity and specificity and is suitable for screening the specific inhibitors of $p56^{lck}$ SH2 function.

  • PDF

An Assay Method for Screening Inhibitors of Prolyl 4-hydroxylase in Immortalized Rat Hepatic Stellate HSC-T6 Cells

  • Choi, Hwa-Jung;Soh, Yun-Jo
    • Biomolecules & Therapeutics
    • /
    • 제15권4호
    • /
    • pp.261-265
    • /
    • 2007
  • Hydroxyproline (HYP) is a post-translational product of proline hydroxylation catalyzed by an enzyme prolyl 4-hydroxylase (P4H) which plays a crucial role in the synthesis of all collagens. Considering the role of collagen and its significance in many clinically important diseases such as liver fibrosis, a great deal of attention has been directed toward the development of an assay at cell-based system. The reason is that cell-based assay system is more efficient than enzyme-based in vitro system and takes much less time than in vivo system. Several assay procedures developed for P4H are laborious, time-consuming and not feasible for the massive-screening. Here, we report the cell-based assay method of prolyl 4-hydroxylase in immortalized rat hepatic stellate HSC-T6 cells. To optimize the cell culture condition to assay for HYP content, various concentrations of reagents were treated for different times in HSC-T6 cells. Our data showed that the treatment with ascorbate in a hypoxic condition for 24 h resulted in the maximal increase of HYP by 1.8 fold. Alternatively, cobalt chloride ($5\;{\mu}M$) and ascorbate ($50\;{\mu}M$) in normoxic states exhibited similar effect on the production of HYP as in a hypoxic condition. Therefore, cobalt chloride can be substituted for a hypoxic condition when an anaerobic chamber is not available. Rosiglitazone and HOE077, known as inhibitors of collagen, synthesis decreased P4H enzyme activity by 32.3% and 15%, respectively, which coincided with previous reports from liver tissues. The level of the smooth muscle ${\alpha}$-actin, a marker of activated stellate cells, was significantly increased under hypoxia, suggesting that our experimental condition could work for screening the anti-fibrotic compounds. The assay procedure took only 3 days after treatment with agents, while assays from the primary stellate cells or liver tissues have taken several weeks. Considering the time and expenses, this assay method could be useful to screen the compounds for the inhibitor of prolyl 4-hydroxylase.

Development of Luciferase Reporter Gene-based Cell Bioassay for the Aromatic Hydrocarbon Receptor Agonists

  • Kim, Sun-Young;Choi, Eun-Jung;Yang, Jae-Ho
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제10권6호
    • /
    • pp.349-354
    • /
    • 2006
  • The aromatic hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates many of the biological and toxicological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related chemicals. The application of recombinant reporter plasmid such as the firefly luciferase gene has proven to be a very effective method to detect these chemicals. The bioassay system, CALUX, is sensitive in directly detecting AhR-agonists from a variety of environmental and biologic materials. However, responses of the AhR-dependent bioassays are dependent on the cell types used. Thus, we developed a sensitive bioassay using the recombinant mouse hepatoma cell (Hepa1c1c7) for the determination of dioxins. The recombinant cell line was stably transfected with firefly luciferase reporter gene (pGudLuc1.1). The transfected cells showed the highest induction of luciferase activity at 4.5 hr and a decrease beyond this time point. The system showed the highest sensitivity of detection ever reported. Upon TCDD exposure cells showed 2 fold increase at 10 pM and 7 fold increase at 100 pM, respectively. The passage number after the transfection played an important role in the sensitivity. The increase of passage number tended to increase the sensitivity of the cells up to 15. The media without phenol red showed a higher induction rate than with phenol red, suggesting the preferable use of phenol red-free media for the bioassay. Since each of the assays has unique characteristics that make them suitable for some screening applications and not others, development of sensitive bioanalytical methods based on a variety of cellular systems in a key to the successful determination of dioxins. The bioassay system developed in this study will contribute to further development of successful screening the AhR agonists among the environmental mixture. In addition, the rapid and sensitive nature of this cellular system can be applied as a valuable tool to screen the dioxin-like moieties among the prodrugs at the initial stage, thereby expediting the new drug discovery.

자체방제계획서 검토기준 마련 연구 (A Study on the Self-Prevention Plan System)

  • 김성범;노혜란;이진선;김정민;안승영;석광설
    • 한국재난정보학회 논문집
    • /
    • 제9권1호
    • /
    • pp.50-55
    • /
    • 2013
  • 자체방제계획서 검토기준과 검토서는 공정안전보고서, 안전성향상계획서 등 안전관리제도의 심사내용과 기준, 심사양식에 관한 고시 및 지침을 분석하였다. 심사 담당인력과의 인터뷰를 통해 심사과정에서 예상되는 문제점을 사전 파악하여 연구에 반영될 수 있도록 하였다. 또한 자체방제계획서 작성항목에 따라 서류검토 및 현장이행실태 등의 검토방법으로 나누어 제안하였다. 자체방제계획서 검토는 유해화학물질관리법에 규정되어 있으나, 실질적인 승인절차가 없어 성과가 미흡했던 "자체방제계획서 검토제도"를 활성화 시키고, 검토반 구성을 통한 업무의 전문성과 효율성을 제고하고자 본 연구를 수행하였다.