• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 동계학술발표회 논문집
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• pp.44-45
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• 2007

• KSBB Journal
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• 제27권5호
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• pp.295-300
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• 2012

Matured dendritic cells (DCs) begin migration with their release from the bone marrow (BM) into the blood and subsequent traffic into peripheral lymphoid and non-lymphoid tissues. Throughout this long movement, migrating DCs must apply specialized skills to reach their target destination. Non-invasive in vivo cell-tracking techniques are necessary to advance immune cell-based therapies. In this study, we used a DiD cell-tracking solution for in vivo dendritic cell tracking in naive mice. We tracked DiD (non-invasive fluorescence dye)-labeled mature dendritic cells using the Near Infrared (NIR) imaging system in normal mice. We examined the immunophenotype of DiD-labeled cells compared with non-labelled mature DCs, and obtained time-serial images of NIR-DC trafficking after mouse footpad injection. In conclusion, we confirmed that DiD-labeled DCs migrated into the popliteal lymph node 24 h after the footpad injection. Here, these data suggested that the cell tracking system with the stable fluorescence dye DiD was useful as a cell tracking tool to advance dendritic cell-based immunotherapy.

• 한국방사선학회논문지
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• 제15권4호
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• pp.555-564
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• 2021

시상은 신경 기능 조절에 중요한 역할을 하는 것으로 알려져 있다. 뇌의 중앙에 위치한 시상은 수면, 각성, 감정 조절에 관여하며, 다발성 경화증, 본태성 떨림, 파킨슨병과 같은 신경퇴행성 질환과 관련이 있는 것으로 보고되고 있다. 또한, 시상의 철 침전물이 나이가 들면서 우울 증상을 유발할 수 있다는 보고가 있다. 연구 간에 차이가 있지만, 시상과 감정 조절, 처리 등의 신경 기능이 밀접한 관계가 있어 시상 영역이 신경 장애에 분명한 영향을 미친다고 추론할 수 있다. Tractography 분석을 통해 각 피질하 영역의 세부 영역 간의 연결성을 매트릭스 형태로 조사하여 강한 연결성과 약한 반구간 연결성을 보였다. 60세 이상 그룹에서 시상의 WM 연결성이 두 그룹보다 약한 것으로 나타났다. 두 그룹을 비교한 결과 젊은 그룹(10-39세 및 40-59세)가 60세 이상 그룹보다 연결 강도가 높았고 각 반구에서 3개의 연결 경로에서 통계적으로 유의한 차이가 발견되었다. 노화로 인한 시상 관련 연결 강도의 감소는 불안 및 우울증과 같은 정서적 및 신경학적 장애에 영향을 미칠 수 있으며 네트워크 측정은 임상 조건 전반에 걸쳐 인지 장애를 평가하는 데 도움이 될 수 있음을 보여주었다.

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.86-90
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• 2013

Various methods have been proposed for enhancing the contrast of laser speckle contrast image (LSCI) in subcutaneous blood flow measurements. However, the LSCI still suffers from low image contrast due to tissue turbidity. Herein, a physicochemical tissue optical clearing (PCTOC) method was employed to enhance the contrast of LSCI. Ex vivo and in vivo experiments were performed with porcine skin samples and male ICR mice, respectively. The ex vivo LSCIs were obtained before and 90 min after the application of the PCTOC and in vivo LSCIs were obtained for 60 min after the application of the PCTOC. In order to obtain the skin recovery images, saline was applied for 30 min after the application of the PCTOC was completed. The visible appearance of the tubing under ex vivo samples and the in vivo vasculature gradually enhanced over time. The LSCI increased as a function of time after the application of the PCTOC in both ex vivo and in vivo experiments, and properly recovered to initial conditions after the application of saline in the in vivo experiment. The LSCI combined with the PCTOC was greatly enhanced even in deep vasculature. It is expected that similar results will be obtained in in vivo human studies.

• 대한핵의학회지
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• 제38권2호
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• pp.198-204
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• 2004

Tumor cell proliferation is considered to be a useful prognostic indicator of tumor aggressiveness and tumor response to therapy but in vitro measurement of individual proliferation is complex and tedious work. PET imaging provides a noninvasive approach to measure tumor growth rate in situ. Early approaches have used $^{18}F$-FDG or methionine to monitor proliferation status. These 2 tracers detect changes in glucose and amino acid metabolism, respectively, and therefore provide only an indirect measure of proliferation status. More recent studies have focused on DNA synthesis itself as a marker of cell proliferation. Cell lines and tissues with a high proliferation rate require high rates of DNA synthesis. $[^{11}C]Thymidine$ was the first radiotracer for noninvasive imaging of tumor proliferation. The short half-life of $^{11}C$ and rapid metabolism of $[^{11}C]Thymidine$ in vivo make the radiotracer less suitable for routing use. Halogenated thymidine analogs such as 5-iodo-2-deoxyuridine (IUdR) can be successfully used as cell proliferation markers for in vitro studies because these compounds are rapidly incorporated into newly synthesized DNA. IUdR has been evaluated as a potential in vivo tracer in nuclear medicing but the image qualify and the calculation of proliferation rates are impaired by its rapid in vivo degradation. Hence, the thymidine analog $3'-deoxy-3'-^{18}F-fluorothymidine$ (FLT) was recently introduced as a stable proliferation marker with a suitable nuclide half-life and stable in vivo. $[^{18}F]FLT$ is phosphorylated to 3-fluorothymidine monophosphate by thymidine kinase 1 and reflects thymidine kinase 1 activity in proliferating cell. $[^{18}F]FLT$ PET is feasible in clincal use and well correlates with cellular proliferation. Choline is a precursor for the biosynthesis of phospholipids (in particular, phosphatidylcholine), which is the essential component of all eukaryotic cell membranes and $[^{11}C]choline$, which is a new marker for cellular proliferation.

• 대한방사성의약품학회지
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• 제7권2호
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• pp.99-103
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• 2021

In this study, the initial in vivo pharmacokinetic changes according to the routes of drug administration were investigated using bioimaging techniques. The purpose of this study was to quantify the degree of distribution of each major organ in normal mice over time by acquiring Positron Emission Tomography/Computed Tomography images while administering routes F-18 fluorodeoxyglucose such as intravenous, intraperitoneal and per oral, a representative diagnostic radiopharmaceutical. Dynamic Positron Emission Tomography images were acquired for 90 minutes after drug administration. Radioactivity uptake was calculated for major organs using the PMOD program. In the case of intravenous administration, it was confirmed that it spread quickly and evenly to major organs. Compared to intravenous administration, intraperitoneal administration was about three times more absorbed and distributed in the liver and intestine, and it was showed that the amount excreted through the bladder was more than twice. In the case of oral administration, most stayed in the stomach, and it was showed that it spread slowly throughout the body. In comparison with intravenous administration, it was presented that the distribution of kidneys was more than 9 times and the distribution of bladder was 66% lower. Since there is a difference in the initial in vivo distribution and excretion of each administration method, we confirmed that the determination of the administration route is important for in vivo imaging evaluation of new drug candidates.

• Journal of Veterinary Science
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• 제22권1호
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• pp.7.1-7.13
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• 2021

Background: Niemann-Pick disease type C (NPC) is caused by the mutation of NPC genes, which leads to the abnormal accumulation of unesterified cholesterol and glycolipids in lysosomes. This autosomal recessive disease is characterized by liver dysfunction, hepatosplenomegaly, and progressive neurodegeneration. Recently, the application of induced neural stem cells (iNSCs), converted from fibroblasts using specific transcription factors, to repair degenerated lesions has been considered a novel therapy. Objectives: The therapeutic effects on NPC by human iNSCs generated by our research group have not yet been studied in vivo; in this study, we investigate those effects. Methods: We used an NPC mouse model to efficiently evaluate the therapeutic effect of iNSCs, because neurodegeneration progress is rapid in NPC. In addition, application of human iNSCs from NPC patient-derived fibroblasts in an NPC model in vivo can give insight into the clinical usefulness of iNSC treatment. The iNSCs, generated from NPC patientderived fibroblasts using the SOX2 and HMGA2 reprogramming factors, were transplanted by intracerebral injection into NPC mice. Results: Transplantation of iNSCs showed positive results in survival and body weight change in vivo. Additionally, iNSC-treated mice showed improved learning and memory in behavior test results. Furthermore, through magnetic resonance imaging and histopathological assessments, we observed delayed neurodegeneration in NPC mouse brains. Conclusions: iNSCs converted from patient-derived fibroblasts can become another choice of treatment for neurodegenerative diseases such as NPC.

• Nuclear Medicine and Molecular Imaging
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• 제43권3호
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• pp.229-239
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• 2009

Molecular imaging strives to visualize processes in living subjects at the molecular level. Monitoring biochemical processes at this level will allow us to directly track biological processes and signaling events that lead to pathophysiological abnormalities, and help make personalized medicine a reality by allowing evaluation of therapeutic efficacies on an individual basis. Although most molecular imaging techniques emerged from the field of oncology, they have now gradually gained acceptance by the cardiovascular community. Hence, the availability of dedicated high-resolution small animal imaging systems and specific targeting imaging probes is now enhancing our understanding of cardiovascular diseases and expediting the development of newer therapies. Examples include imaging approaches to evaluate and track the progress of recent genetic and cellular therapies for treatment of myocardial ischemia. Other areas include in vivo monitoring of such key molecular processes as angiogenesis and apoptosis, Cardiovascular molecular imaging is already an important research tool in preclinical experiments. The challenge that lies ahead is to implement these techniques into the clinics so that they may help fulfill the promise of molecular therapies and personalized medicine, as well as to resolve disappointments and controversies surrounding the field.

• 한국광학회지
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• 제25권2호
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• pp.67-71
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• 2014

혈관 내 OCT (optical coherence tomography) 는 혈관 벽 내부의 3차원적 미세구조를 영상화할 수 있어서 임상에서 각광을 받고 있다. 하지만 아직도 충분하지 못한 이미징 속도, 특히 내시경 프로브의 이미징 광 스캐닝 속도의 부족으로 혈관 길이 방향의 이미징 간격이 실제 시스템의 광학적 해상도보다 5배 이상 커서 혈관 종방향으로의 고해상도 이미징이 얻어지지 못하고 있는 상황이다. 본 논문에서는 초당 350장의 혈관 벽 단층 영상을 제공하는 고속 혈관 내 OCT 시스템을 기술한다. 본 시스템과 내시경 장치를 이용하여 47 mm 길이의 살아있는 토끼 대동맥을 3.7초만에 34 micron의 혈관 종방향 간격으로 얻는데 성공하였다. 34 micron의 종방향 간격은 실제 내시경의 그 방향 광학적 해상도와 비슷한 정도로서 3차원 모든 방향으로의 고해상도 이미징을 구현하였음을 보여준다. 얻어진 이미징 데이터의 3차원 영상 구현을 통해 혈관의 미세구조 및 이미징 전 삽입된 스텐트의 자세한 구조를 보였다.

• 대한방사성의약품학회지
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• 제7권2호
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• pp.133-140
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• 2021

Various iron oxide nanoparticle-based radiomaterials(IO-NRM) can be used for multimodal imaging of magnetic resonance imaging and molecular imaging, can be easily sized, can be easily functionalized, and have biocompatibility, making them a very good platform for molecular imaging. Based on the previously revealed molecular imaging technology of iron oxide nanoparticles, this paper introduces the in vivo distribution and use in various diseases through iron oxide nanoparticles-based radiolabeled compounds for diagnosis and treatment of iron oxide nanoparticles-based molecular imaging platforms. We would like to look forward to its potential as a radiopharmaceutical.