Efficient VEGF gene expression using hypoxia-inducible neuron-specific vector system

의과대학/석사Since neurons play a critical role in the central nervous system, neuron-target gene expression system is important for gene therapy. Ischemic neurons following injury affect disruption of neurovascular unit which is mediated by astrocyte. Also reactive astrocyte contributes to astrogliosis that aggravate traumatic environment. Therefore, controllable gene expression system that expressed in neurons selectively more than glial cells and other cell types is necessary. We used neuron-specific enloase (NSE) promoter to target neurons. NSE is one of glycolytic isoenzymes and abundant in adult brain neurons due to their characteristics of expression in matured neurons. Because NSE is expressed high in various neuronal cell types, we can design neuron-target gene expression system using NSE promoter. Also, to improve gene expression under hypoxic ischemic environment like spinal cord injury (SCI), the combination of erythropoietin (Epo) enhancer and NSE promoter was used. Vascular endothelial growth factor (VEGF) is an angiogenic peptide and has neuroprotective effects as well as angiogenesis. VEGF is considered good therapeutic gene because it protects injured neurons and promotes sprouting of blood vessels to support cell survival. In this study, the use of NSE promoter increases the expression of luciferase reporter gene and VEGF gene. The luciferase and VEGF gene expression is the highest with the plasmid vector including Epo enhancer under hypoxic conditions and also showed proliferation effect. With this hypoxia-inducible neuron-specific gene expression system, applied gene or cell therapy is promising to regenerate SCI.ope

관상동맥질환군에서 Nitric Oxide 농도와 Nitric Oxide Synthase 유전자 다형성과의 관련성

학위논문(석사)--서울대학교 대학원 :의학과 임상병리학전공,2000.Maste

ALS 환자 유래 세포 모델에서 크리스퍼 유전자 가위를 이용한 변이 유전자 ATP7A의 교정

prohibition박

Study on the association between genetic polymorphism and expression of CD36 in Korean patients with coronary heart disease

학위논문(박사)--서울대학교 대학원 :의학과 임상병리과학전공,2004.Docto

Application of the Analytical Performance Specification for Quality Management of Clinical Chemistry Tests

임상 검사실에서 품질관리 시스템의 구현은 환자 진료를 위한 다양한 검사결과의 품질관리에 필수적이다. 분석수행사양(analytical performance speci cation)은 임상적 요구사항이 충족되었는지를 평가하는 중요한 기준이 되며, 품질관리 결과를 효과적으로 평가하기 위해서 적절한 근거에 기반한 판정기준을 설정하는 것이 중요하다. 본 종설에서는 각 평가 지침에 대한 일련의 판정기준으로 분석수행사양의 목표를 제공하여 검사실에서 이를 보다 쉽게 활용할 수 있도록 하고자 하였다. 이를 위해 정밀도, 직선성 검정, 측정 방법 또는 검체 간의 비교, 시약 로트 간 비교, 변화치검색, 검사방법의 바이어스 평가를 포함하여 임상 검사실의 품질관리에 사용되는 CLSI (임상 및 검사실 표준 연구소) 평가 지침을 조사하였다. ‘대한임상학회 검사표준화및질향상위원회’의 토의를 거쳐 각 지침에서 제시하는 평가기준의 정의와 각 지침과 관련된 비정밀도, 바이어스, 총허용오차 등 분석수행사양의 종류를 제안하였다. 또한, 각 임상화학검사에 대하여 다양한 근거를 기반으로 한 복수의 분석수행사양 목표를 제시함으로써 임상 검사실이 목표로 설정해야 할 검사 성능 수준에 대한 일반적인 범위를 제공하고자 하였다. 본 종설에서 제안된 자료를 통하여 다양한 임상화학검사에 대한 효과적인 품질관리를 촉진하고 각 검사실의 고유한 상황에 맞는 분석수행사양 목표 선택 및 적용 과정을 용이하게 할 것으로 기대된다. In the realm of clinical laboratories, the implementation of a quality management system is vital for the quality management of various test results for patient treatment. Analytical performance specifications (APS) serve as the critical criteria for assessing whether clinical requirements have been fulfilled, and ensuring that these standards are based on appropriate evidence is crucial to effectively estimate the processes and outcomes of the quality management system. Our aim was to define practical APS goals as acceptability criteria for evaluating test quality. This would make it straightforward for laboratories to apply these guidelines. To this end, we examined relevant Clinical and Laboratory Standards Institute guidelines employed in the quality management of clinical laboratories, such as encompassing precision, linearity, comparison between measurement procedures or samples, comparison between reagent lots, delta check of patients’ results, bias evaluation of test methods, among others. Furthermore, after discussion with the Committee on Standardization and Quality Improvement of Korean Society of Clinical Chemistry, we proposed definitions on the evaluation criteria provided in each guideline and the types of APS such as imprecision, bias, and the total allowable error corresponding to them. Setting multiple evidence-based APS goals for each clinical chemistry test would assist in establishing a range of performance levels that clinical laboratories should aim for. We expect the data suggested in this review to facilitate effective quality management for various clinical chemistry tests and simplify the selection and application of APS for the unique circumstances of each laboratory

Recent Trends in Creatinine Assays in Korea: Long-Term Accuracy-Based Proficiency Testing Survey Data by the Korean Association of External Quality Assessment Service (2011-2019)

Background: Accurate serum creatinine (Cr) concentration measurement is essential for evaluating kidney function. In 2011, the Korean Association of External Quality Assessment Service (KEQAS) launched an accuracy-based Cr proficiency testing (ABCr PT) survey. We analyzed long-term data of the KEQAS ABCr PT survey collected between 2011 and 2019 to assess recent trends in Cr assays in Korea. Methods: The ABCr PT survey including three commutable fresh-frozen serum samples was performed twice a year. The target Cr concentration was assigned using isotope-dilution mass spectrometry. We analyzed data obtained from the participating laboratories, calculated the yearly bias, and evaluated bias trends for the major reagents and instruments. Outliers were excluded from all analysis. Results: The mean percentage bias based on the total data of all participating laboratories was 10.8% in the 2011-A survey and 0.2% in 2019-B survey. Bias for the major reagents and instruments differed depending on the manufacturer. Enzymatic assays generally showed desirable bias ranging from -3.9% to 3.2% at all Cr concentrations and lower interlaboratory variability than non-enzymatic assays (enzymatic vs. non-enzymatic, 3.3%-7.2% vs. 6.3%-9.1%). Conclusions: Although the mean percentage bias of Cr assays tends to decrease over time, it is necessary to continuously strive to improve Cr assay accuracy, especially at low concentrations

Immunosuppressive Drug Measurement by Liquid Chromatography Coupled to Tandem Mass Spectrometry: Interlaboratory Comparison in the Korean Clinical Laboratories

Background: Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is increasingly used for immunosuppressive drug tests. However, most LC-MS/MS tests are laboratory-developed and their agreement is unknown in different Korean laboratories. This interlaboratory comparison study evaluated test reproducibility and identified potential error sources. Methods: Test samples containing three concentrations of tacrolimus, sirolimus, everolimus, cyclosporine, and mycophenolic acid were prepared by pooling surplus samples from patients undergoing routine therapeutic drug monitoring and tested in duplicate in the participating 10 clinical laboratories. Reconstitution and storage experiments were conducted for the commonly used commercial calibrator set. The robust estimators of reproducibility parameters were calculated. Spearman's rank correlation coefficient (rho, rho) was used to evaluate the correlation between drugs. Multiple linear regression was used to determine whether the experimental conditions alter the calibration curves. Results: The reproducibility coefficient of variation exceeded 10% only for sirolimus concentrations 1 and 2 (10.8% and 12.5%, respectively) and everolimus concentrations 1 and 2 (12.3% and 11.4%, respectively). The percent difference values showed weak correlations between sirolimus and everolimus (rho=0.334, P=0.175). The everolimus calibration curve slope was significantly altered after reconstitution following prolonged 5 degrees C storage (P=0.015 for 14 days; P=0.025 for 28 days); the expected differences at 6 ng/mL were 0.598% for 14 days and 0.384% for 28 days. Conclusions: LC-MS/MS test reproducibility for immunosuppressive drugs seems to be good in the Korean clinical laboratories. Continuous efforts are required to achieve test standardization and harmonization, especially for sirolimus and everolimus