IL2 is required for functional maturation of regulatory T cells

전필현,오권익 한국통합생물학회 2017 Animal cells and systems Vol.21 No.1

Regulatory T cells (Tregs), specified by the expression of transcription factor Foxp3, operate Foxp3- dependent programs to maintain self-tolerance. In addition to Foxp3, other tissue-specific transcription factors are also required by Tregs to control the corresponding immune responses like follicular Tregs which express both Foxp3 and Bcl6 controlling germinal center reactions. Here, we show that Interleukin 2 (IL2) is required for the optimal expression of T helper type 1 (Th1) transcription factor T-box 21 (Tbx21, T-bet) in Tregs. The expression levels of CXCR3 and Tbet were reduced in IL2 deficient Tregs. Furthermore, IL2 deficient Treg cells failed to control the proliferation of CD4+ T cells in vitro and could not prevent the progression of colitis characterized by Th1 immune responses. Taken together, our data suggest that IL2 is essential for the functional maturation of Tregs including the optimal suppressive activity and the expression of tissue-specific transcription factors like T-bet.

體液을 利用한 惡性腫瘍診斷法

全弼鉉,朴吉秀,康柄鎬 醫藥係社 1958 綜合 醫學 Vol.3 No.3

전산화단층촬영조영술에서 화질 최적화를 위한 딥러닝 기반 및 하이브리드 반복 재구성의 특성분석

전필현,이창래 한국방사선학회 2023 한국방사선학회 논문지 Vol.17 No.1

전산화단층촬영조영술(computer tomography angiography, CTA)의 최적 화질을 위한 서로 다른 요오드 농도와 스캔 매개변수를 적용하여 필터 보정 역투영 (filtered back projection, FBP), 혼합형 반복재구성 (hybrid-iterative reconstruction, hybrid-IR) 및 딥러닝 재구성 (deep learning reconstruction, DLR)의 화질적 특성을 정량적으로 평가하였다. 320행 검출기 CT 스캐너에서 지름 19 cm의 원통형 물 팬텀 가장자리에 있는 다양한 요오드 농도 (1.2, 2.9, 4.9, 6.9, 10.4, 14.3, 18.4 및 25.9 mg/mL)의 팬텀을 스캔하였다. 각각의 재구성 기술을 사용하여 획득한 데이터는 노이즈 (noise), 변동 계수 (coefficient of variation, COV) 및 평균 제곱근 오차 (root mean square error, RMSE)을 통해 영상을 분석하였다. 요오드의 농도가 증가할수록 CT number 값은 증가하였지만 노이즈 변화는 특별한 특성을 보이지 않았다. 다양한 관전류 및 관전압에서 FBP, adaptive iterative dose reduction (AIDR) 3D 및 advanced intelligent clear-IQ engine (AiCE)에 대해 요오드 농도를 증가할수록 COV는 감소하였고 요오드 농도가 낮을 때는 재구성 기술 간의 COV 차이가 다소 발생하였지만, 요오드 농도가 높아짐에 따라 그 차이는 미약한 결과를 보였다. 또한, AiCE에서는 요오드 농도가 높아질수록 RMSE는 감소하지만 특정한 농도 (4.9 mg/mL) 이후에는 RMSE가 오히려 증가 되는 특성을 보여주었다. 따라서 최적의 CTA 영상 획득을 위해 재구성 기술에 따른 요오드 농도의 변화 및 다양한 관전류 및 관전압의 스캔 매개변수의 특성을 고려하여 환자 스캔을 해야 할 것이다.

去勢白鼠 및 睾丸移植白鼠血淸이 肝細胞核分裂에 미치는 影響에 關한 實驗的 硏究

全弼鉉 醫藥係社 1963 綜合 醫學 Vol.8 No.5

Whole-body CT in Polytrauma Patients: The Effect of Arm Position on Abdominal Image Quality When Using a Human Phantom

전필현,김희중,이창래,김대홍,이원형,전성수 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.11

For a considerable number of emergency computed tomography (CT) scans, patients are unable to position their arms above their head due to traumatic injuries. The arms-down position has been shown to reduce image quality with beam-hardening artifacts in the dorsal regions of the liver, spleen, and kidneys, rendering these images non-diagnostic. The purpose of this study was to evaluate the effect of arm position on the image quality in patients undergoing whole-body CT. We acquired CT scans with various acquisition parameters at voltages of 80, 120, and 140 kVp and an increasing tube current from 200 to 400 mAs in 50 mAs increments. The image noise and the contrast assessment were considered for quantitative analyses of the CT images. The image noise (IN), the contrast-to-noise ratio (CNR), the signal-to-noise ratio (SNR), and the coefficient of variation (COV) were evaluated. Quantitative analyses of the experiments were performed with CT scans representative of five different arm positions. Results of the CT scans acquired at 120 kVp and 250 mAs showed high image quality in patients with both arms raised above the head (SNR: 12.4, CNR: 10.9, and COV: 8.1) and both arms flexed at the elbows on the chest (SNR: 11.5, CNR: 10.2, and COV: 8.8) while the image quality significantly decreased with both arms in the down position (SNR: 9.1, CNR: 7.6, and COV: 11). Both arms raised, one arm raised, and both arms flexed improved the image quality compared to arms in the down position by reducing beam-hardening and streak artifacts caused by the arms being at the side of body. This study provides optimal methods for achieving higher image quality and lower noise in abdominal CT for trauma patients.

Brain Computed Tomographic Angiography에서 Locator변화에 따른 조영증강에 대한 연구

전필현(Pil Hyun Jeon),이원형(Won Hyung Lee),전성수(Seang Su Jeon) 대한전산화단층기술학회 2010 대한CT영상기술학회지 Vol.12 No.2

Purpose In contrast enhanced imaging, a contrast agent is introduced into the anatomy of a patient, typicaⅡy by way of an intravenous or intra-arterial injection. FoⅡowing a delay which aⅡows the contrast agent to reach a region of interest(ROI) of the patient’s anatomy, a scan of the region is initiated. A bolus tracking scan is coordinated to coincide with the presence of the contrast agent at the ROI, as scanning either too early or too late can result in less dian optimal enhancement, and possibly require that the patient be rescanned. To achieve standard contrast enhancement appropriately throughout the location of the target vessels, this study was undertaken the locator placed in the descending aorta for the brain computed tomographic angiography(CTA). Materials and methods The study was conducted using brain CTA for patients who presented at our hospital from November 2009 to February 2010. Optimization of bolus timing was used at a place of the locator in the descending aorta via a 64-detector row CT brain angiography. Results When compared place descending aorta in the locator with internal carotid artery and random locator around avoiding the neck vessels, descending aorta in the locator more contrast enhancement. So the cases reduce probability protect missing the enhancement time and the target regions and increasing three-dimensional processing time. Conclusion This study is reduced that more insufficient arterial contrast or excessⅣe venous enhancement, which can be placed of a locator in the descending artery. And that is good arterial contrast with little venous contamination. Our investigation provides to the optimal enhance time product by merging the three-dimensional representations of circle of wiⅡis portion and common carotid artery bifurcation more than valuable diagnostic images for helpful diagnosis and therapy using optimal enhancement according to change of locator in brain CTA.

급성 뇌경색 환자의 혈전용해제(tPA) 투여를 위한 BEST Protocol의 유용성

전필현(Pil Hyun Jeon),전성수(Seong Su Jeon) 대한CT영상기술학회 2009 대한CT영상기술학회지 Vol.11 No.1

Purpose Stroke is the third leading cause of death in the industrialized world and the primary contributor of disability claims. Because 70% of all stroke victims are over 65, Medicare spends more on post-acute care for these patients than for acute in-patient hospital care. As the elderly population continues to grow, the situation will only worsen. This research could change BEST(brain salvage through emergent stroke therapy) protocol on how stroke patients are triaged and potentially extend treatment opportunity for those who are receiving intravenous recombinant tissue plasminogen activator- tPA(trombolytic drug) within three-to-six hour window of stroke onset. CT Perfusion imaging may dramatically improve the speed and accuracy of stroke diagnosis, enabling physicians to avoid potentially threatening complications from tPA use. In cases where our hospital used CT brain perfusion the average time between the emergency room neurological exam and CT scan time was 30minutes. At our hospital we were able to save valuable time by performing BEST protocol simultaneously with CT brain perfusion. Materials and methods For the study at Wonju Christian hospital, we conducted a retrospective analysis of 154 patients suspected of acute ischemic stroke who underwent CT brain perfusion as part of BEST protocol. 56 of these patients received tPA injections. This study was conducted with patients who presented at WCH from March, 2008 to February 2009. We used BEST protocol, performed with Philips 64 channel Brilliance CT equipment. Results We compared the time taken before and after the use of BEST protocol. The time advantage by performing BEST protocol between the emergency room neurological exam and CT scan was 24 minutes. Conclusion The study finding may have significant effect on visiting acute ischemic stroke patients. Through BEST protocol using pop up window, CT scan time was reduced by 50%. This process will dramatically improve hospital diagnostic time, most of all by reducing CT scan time, thereby helping the emergency room save precious time in stroke diagnosis, target treatment, and reduce the risks of inappropriate tPA use.

관상동맥 CT와 심근관류 CT 검사를 이용한 고농도 조영제와 저농도 조영제 간 비교 평가

차성진,고동희,전필현,고성민 대한CT영상기술학회 2024 대한CT영상기술학회지 Vol.26 No.1

최근 CT 기술의 발전으로 저관전압 사용할 수 있으면서 저농도 조영제의 임상적 유용성이 점차 입증되고 있다. 본 연구에서는환자의 혈역학적 분포와 심근의 평가를 동시에 수행할 수 있는 관상동맥 CT(Coronary Computed Tomography Angiography; CCTA) 검사와 역동적 심근관류 CT(Computed Tomography–Myocardial Perfusion Imaging; CT-MPI) 검사를 통하여 고농도와저농도 조영제 간의 차이를 비교하였다. 연구 결과 CCTA의 조직과 혈관에 대한 정량적 분석에서 고농도 조영제가 5~10% HU가 높았지만, 유의확률이 0.05 이상으로 나타났다. CCTA와 CT-MPI를 통한 심근 평가 결과 두 조영제 간 차이가 5% 이내였으며 유의확률이 0.05 이상으로 나타났다. 정성적 분석은 다섯 가지 범주로 명목적인 측정을 하였고 저농도 조영제와 고농도 조영제 간의 유의확률 0.05 이상으로 유의미한 차이점을 밝혀내지 못했다. 본 연구는 고농도와 저농도 조영제를 CCTA와 CT-MPI 검사에 적용하여 기존의 연구들과 차별성을 가졌다. CCTA와 CT-MPI를 통한 분석에서는 고농도 조영제를 사용한 영상보다저농도의 영상이 열등하지 않다는 결과를 보여준다. 연구 대상자의 표본이 더 모이고 본 연구에서 제시한 한계점을 극복한다면 CCTA와 CT-MPI에서 고농도 조영제를 사용하는 기존의 검사법에서 벗어나 저농도 조영제를 사용함으로써 환자의 조영제 부작용에 대한 부담을 크게 줄일 수 있을 것이다. With the advancement of CT technology, the use of low tube voltages, and the clinical efficacy of low-concentration contrast media are gradually being demonstrated. In this study, we compared the differences between high- and low-concentration contrast media using Coronary Computed Tomography Angiography (CCTA) and Computed Tomography–Myocardial Perfusion Imaging (CT-MPI). These imaging techniques can simultaneously evaluate the patient's hemodynamic distribution and myocardium. The study results indicated that the quantitative analysis of tissues and blood vessels in CCTA showed that high-concentration contrast media led to a 5 to 10% increase in Hounsfield Units (HU), but the probability of significance was greater than 0.05. As a result of myocardial evaluation using CCTA and CT-MPI, the difference between the two contrast agents was within 5%, and the probability of significance was greater than 0.05. Qualitative analysis utilized nominal measurements in five categories and did not reveal significant differences between low- and high-concentration contrast media with a significance probability greater than 0.05. This study differed from existing studies by utilizing high- and low-concentration contrast media for CCTA and CT-MPI examinations. Analysis using CCTA and CT-MPI shows that low-concentration images are not inferior to images obtained using high-concentration contrast media.

외상성 두부 손상 환자의 추적관찰 CT검사 시 딥러닝 재구성 기법을 활용한 초저선량 두부 CT의 유효성 평가

전상현,고동희,전필현,Chuluunbaatar Otgonbaata,김진우 대한CT영상기술학회 2024 대한CT영상기술학회 학술대회자료집 Vol.2024 No.1

急性出血性 膵炎에 對한 外科的 考察

金子勳,金禮欽,全弼鉉,金亨奎 醫藥係社 1963 綜合 醫學 Vol.8 No.5