• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.52-52
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• 2003

악성종양을 치료하는 방법중 방사선과 온열요법은 가장 강력한 치료방법으로 연구되어왔으며 이를 병용함으로 서 상승효과를 얻을 수 있다. 인체조직에 41$^{\circ}C$ 이상의 열을 가하면 세포질의 단백질변성으로 세포에 손상을 주어 세포가 사멸하게 되며 세포의 생존율은 가열시간 즉 열량에 따라 지수적으로 감소한다. 온열은 세포주기중 방사선 저항성이 매우 큰 DNA 합성시기와 산도가 높을 때 감수성이 매우 크기 때문에 방사선과 병용요법은 상호 상승효과를 가져온다. 이와 같이 온열을 이용한 악성종양의 치료가능성은 생물학적 기초연구와 임상시험에서 경이적인 효과를 얻을 수 있었으나 아직 까지 가열방법과 온도분포측정이 큰 과제로 남아있으며 주위건강조직의 가열을 피하면서 인체 깊은 곳에 존재하는 종양에만 집중 가열하는 방법인 삽입형 온열치료방법에 대한 연구가 집중되었다. 한편 방사선 치료방법은 주위 건강조직의 피폭을 최소로 줄이고 종양에만 집중 조사가 요구되며 자궁암, 유방암, 뇌암등 부피가 작고 집중적 치료를 요하는 종양은 방사성동위원소를 이용한 근접 삽입치료 (Brachyradiotherapy)가 큰 효과를 나타내고 있다 방사선과 온열의 병행 치료를 위하여 방사선 삽입 치료에 사용한 선원 삽입관을 그대로 두고 삽입관 속에 방사성 동위원소 대신 온열 전극을 넣어 열을 가하는 방사선 온열 병용치료방법을 고안하였으며 방사선과 온열병용에 사용할 최적 삽입관의 제작과 이에 따른 온도분포의 측정과 최적삽입방법을 결정하였다. 방사선 삽입치료용 폴리에찌렌 삽입관의 외부에 금박을 입혀 라디오파 첨극을 삽입할 때 서로 연결되도록 고안 제작함으로서 방사선 삽입치료와 자입식 온열치료를 동시에 만족하게 수행할 수 있는 병용삽입관 (Flexible thermoradiotherapy probes)을 제작하였다. 전도율이 큰 금박부위가 직접 조직에 접촉됨으로 라디오파의 전달이 용이하며 금박의 길이를 2 cm 에서 5 cm 로 구분제작 함으로서 종양의 크기와 모양에 따라 선택할 수 있도록 하였다. 라디오파를 이용한 온열분포의 측정은 인체조직과 전기적 특성이 비슷한 물질인 한천 팬텀 제작하여 사용하였으며 온도분포 측정은 열전대와 서머그람으로 시행하였다. 생체조직 내에서의 온도분포와 온열효과를 관찰하기 위하여 직접 개의 뇌를 이용하여 시행하였으며 4 개의 전극을 이용하여 43$^{\circ}C$로 50분간 가열하고 일주일후 개를 회생시켜 개 뇌에 대한 조직학적 검사를 시행하였다. 한편 팬텀 표면에서 중앙부로 안테나 길이가 2 cm 인 4 개의 전극을 1 cm 간격으로 정사각형이 되도록 삽입하여 가열하였을 때 90% 등온곡선이 반경 1.25의 원형으로 균일하게 분포되었고 종단면상 삽입관의 길이에 따라 균일한 온도분포가 이루어졌다. 전극을 2 cm 간격으로 삽일 하였을 때 90% 등온곡선이 1.75 반경으로 거의 4 각형의 균일한 분포를 얻었으나 전극의 간격이 증가하면 전도율이 떨어져서 전극 중심부에 불균일한 온도분포를 형성하였다. 동물실험에서 정상 개의 뇌 실질에 자입하여 직접 정방형의 중심을 43$^{\circ}C$로 유지하며 50분간 온열 요법을 시행한 후 관찰한 조직병리학적 소견은 liquefactive necrosis, pyknosis of neuronal element 및 polymorphonuclear leukocytes들의 회백질에서 급성기에 관찰되었고 liquefactive necrosis 주위에 lipid-laden macrophage들이 관찰됨이 공통적인 특정이었으며 후기변화로 괴사조직 주위로 신경교세포의 증식이 관찰되었다.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.445-454
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• 2019

Layered double hydroxides (LDHs) nanoparticles have emerged as novel nanomaterials for bio-imaging applications due to its unique layered structure, physicochemical properties, and good biocompatibility. Bio-imaging is one of the most important fields for medical applications in clinical diagnostics and therapeutics of various diseases. Enhanced diagnostic techniques are needed to realize new paradigm for next-generation personalized medicine through nanoscale materials. When nanotechnology is introduced into bio-imaging system, nanoparticle probes can endow imaging techniques with enhanced ability to obtain information about biological system at the molecular level. In this review, we summarize structural features of LDH nanoparticles with current issues of bio-imaging system. LDH nanoparticle probes are also discussed through in vitro as well as in vivo studies in various bio-imaging techniques including fluorescence imaging, magnetic resonance imaging (MRI), positron emission tomography (PET), and computed X-ray tomography (CT), which will have the potential in the development of the advanced nanoparticles with high sensitivity and selectivity.

• Korean Journal of Biological Psychiatry
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• v.2 no.2
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• pp.205-217
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• 1995

In comparison with tricyclic antidepressants(TCAs), one of the most interesting characteristics of selective serotonin reuptake inhibitors(SSRIs) is its structural differences, reveals different pharmacological properties. The applications at the moment are most effective in clinical applications to depression. The limited result of the research to date on the various applications of SSRIs has not revealed the total potential and applicability of SSRIs. Therefore, attending physicians utilizing SSRIs do not know the full capabilities of the drug on patients and what the patients may reap in terms of benefit from its curing elements. Physicians must first try to understand the full potential of SSRIs and its potential applications for it to be effective on patients. recently, it has been determined that SSRIs and other drugs when administered together may be more effective in the healing process because SSRIs complements and aids in the enhancement and effect of the other drugs. This article is written to give attention to the reader of the pharmacological properties and the clinical use of SSRIs. It is the authors's hope that continuous research on the particular aspects of SSRIs can aid the clinicians in the use of this SSRIs.

• The Korean Journal of Nuclear Medicine
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• v.36 no.4
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• pp.244-254
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• 2002

Purpose: This study investigated the differences between technetium-99m ethyl cysteinate dimer (Tc-99m ECD) and technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) uptake in the normal brain by means of statistical parametric mapping (SPM) analysis. Materials and Methods: We retrospectively analyzed age and sex matched 53 cases of normal brain SPECT. Thirty-two cases were obtained with Tc-99m ECD and 21 cases with Tc-99m HMPAO. There were no abnormal findings on brain MRIs. All of the SPECT images were spatially transformed to standard space, smoothed and globally normalized. The differences between the Tc-99m ECD and Tc-99m HMPAO SPECT images were statistically analyzed using statistical parametric mapping (SPM'99) software. The differences bgetween the two groups were considered significant ant a threshold of corrected P values less than 0.05. Results: SPM analysis revealed significantly different uptakes of Tc-99m ECD and Tc-99m HMPAO in the normal brains. On the Tc-99m ECD SPECT images, relatively higher uptake was observed in the frontal, parietal and occipital lobes, in the basal ganglia and thalamus, and in the superior region of the cerebellum. On the Tc-99m HMPAO SPECT images, relatively higher uptakes was observed in subcortical areas of the frontal region, temporal lobe, and posterior portion of inferior cerebellum. Conclusion: Uptake of Tc-99m ECD and Tc-99m HMPO in the normallooking brain was significantly different on SPM analysis. The selective use of Tc-99m ECD of Tc-99m HMPAO in brain SPECT imaging appears especially valuable for the interpretation of cerebral perfusion. Further investigation is necessary to determine which tracer is more accurate for diagnosing different clinical conditions.

• The Korean Journal of Nuclear Medicine
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• v.35 no.3
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• pp.131-141
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• 2001

Purpose: We evaluated the sensitivity of the F-18 FDG PET by visual assessment and statistical parametric mapping (SPM) analysis for the localization of the epileptogenic zones in frontal lobe epilepsy. Materials and Methods: Twenty-four patients with frontal lobe epilepsy were examined. All patients exhibited improvements after surgical resection (Engel class I or II). Upon pathological examination, 18 patients revealed cortical dysplasia, 4 patients revealed tumor, and 2 patients revealed cortical scar. The hypometabolic lesions were found in F-18 FDG PET by visual assessment and SPM analysis. On SPM analysis, cutoff threshold was changed. Results: MRI showed structural lesions in 12 patients and normal results in the remaining 12. F-18 FDG PET correctly localized epileptogenic zones in 13 patients (54%) by visual assessment. Sensitivity of F-18 FDG PET in MR-negative patients (50%) was similar to that in MR-positive patients (67%). On SPM analysis, sensitivity decreased according to the decrease of p value. Using uncorrected p value of 0.05 as threshold, sensitivity of SPM analysis was 53%, which was not statistically different from that of visual assessment. Conclusion: F-18 FDG PET was sensitive in finding epileptogenic zones by revealing hypometabolic areas even in MR-negative patients with frontal lobe epilepsy as well as in MR-positive patients. SPM analysis showed comparable sensitivity to visual assessment and could be used as an aid in the diagnosis of epileptogenic zones in frontal lobe epilepsy.

• The Korean Journal of Nuclear Medicine
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• v.35 no.5
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• pp.334-341
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• 2001

Purpose: Ascorbic acid us known to act as an antioxidant. Therefore, it can be used in increasing the efficiency of radiochemical labeling of Technetium-99m setamibi by inhibition of oxidation of $Sn^{2+}$ at low concentration. We intended to estimate the efficiency of radiochemical labeling and the stability of the newly formed formulation when ascorbic acid was added to a commercial kit. Materials and Methods: Synthesis of sestamibi was performed according to Dong-A's patent procedure (No.10-2001-0012877). First, we undertook a study to evaluate the efficiency of radiochemical labeling of sestamibi containing ascorbic acid. The stability of the vials was assessed using either $7.5{\mu}g\;or\;75{\mu}g$ of ascorbic acid, added to commercial vials under the accelerated condition(Temp : $40^{\circ}C{\pm}2^{\circ}C$, Relative humidity : $75{\pm}5%$). Results: Sestamibi was synthesized in overall 35-40% yield over 5 steps from a commercially available methallyl chloride as a starling material. When ascorbic acid was added, the efficiency of radiochemical labeling was maintained compared to the vial with no ascorbic acid. The accelerated test showed that the addition of ascorbic acid inhibited the oxidation of $Sn^{2+}$ ion by antioxidation mechanism. Also, the efficiency of radiochemical labeling of this vial after 9 months was nearly the same as the starting point. Therefore, the storage period of the kit is likely to be extended. Taken together, it suggests that the addition of ascorbic acid as a stabilizer is desirable. Conclusion: To increase the stability of a sestamibi cold kit, it is desirable to add ascorbic acid as a stabilizer to the commercial formulation.

• Korean Journal of Biological Psychiatry
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• v.9 no.1
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• pp.25-33
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• 2002

Serotonin transporter(5-HTT) is one of the major action site of antidepressants in neuronal cells. According to the recent studies, it is known that the functional polymorphism in the promoter region of the 5-HTT gene(5-HTT linked polymorphism repetitive element in promoter region, 5-HTTLPR) is associated with antidepressant responsiveness, and the distributions of 5-HTTLPR is various among the different populations. Our preliminary study suggested that it is possible to measure the endophenotype of 5-HTTLPR genotype by examining the pharmacodynamic research of the 5-HTT in platelet membranes. However, there are limitations to predicting the antidepressant responsiveness only from the endophenotypic characteristics of 5-HTT gene promoter polymorphism, and therefore we propose to use the pharmacogenomic methods for overcoming these limitations. We found that the significant correlations existed among the genetic polymorphisms of biogenic amine transporters whose structure and characteristics are similar to the 5-HTT, and the predictable odds ratio of antidepressant responsiveness are increased significantly by combining the effect with other associated polymorphisms, compared to the effect of 5-HTT promoter polymorphism only. These results support the hypothesis that antidepressant treatment has to be individualized according to the genetic and ethnic background of depressed patients. It would be possible to develope the evaluation tools to predict the antidepressant responsiveness and its side effect profile, if scientists reveal the genes related to the action mechanism as well as the metabolism of antidepressants so as to discover the interaction of those genes and contribution of endogenotypes toward antidepressant responsiveness.

• The Korean Journal of Nuclear Medicine
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• v.4 no.1
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• pp.1-9
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• 1970

철대사(鐵代謝)에 관(關)한 연구(硏究)는 과거(過去) 30년(年)동안 새로운 검사방법(檢査方法)의 도입(導入)으로 눈부신 발전(發展)을이룩하였다. 1937년(年) Heilmeyer 등(等)에 의(依)하여 Ortho-phenanthrolin방법(方法)의 개발(開發)로 저색소성빈혈(低色素性貧血)의 원인(原因)이 구명(究明)되고 또한 이에 대(對)한 치료(治療)의 원칙(原則)이 세워졌다. 그 후 심(甚)한 감염(感染)이나 악성종양(惡性腫瘍)을 가진 환자(患者)者에서 관찰(觀察)되는 빈혈(貧血)에 대(對)해서 하나의 가설(假說)을 세워 이를 설명(說明)하려 하였는데 이는 곧 혈장(血漿)으로부터 철분(鐵分)이 신속(迅速)히 소실(消失)되어 망내계(網內系)나 병변(病變)이 있는 국소부위(局所部位)에 주(主)로 모여 들어 특수(特殊)한 방어기능(防禦機能)을 발휘(發揮)한다는것으로 연자(演者)는 방사성동위원소(放射性同位元素)를 이용(利用)하여 이 가설(假說)을 증명(證明)하였으며 이 연구(硏究)에는 또한 이문호교수(李文鎬敎授)가 Freiburg대학(大學) 유학중(留學中) 참여(參與)한 바 있다. 철대사(鐵代謝)를 파악(把握)하기 위(爲)해서 $^{59}Fe$가 흔히 사용(使用)되는데 이러한 방사성동위원소(放射性同位元素)를 이용(利用)함으로서 다음 사항(事項)들을 관찰(觀察)할 수 있었다. 즉(卽) 1. 소화장기(消化臟器)로 부터의 철흡수(鐵吸收) 2. 혈장(血漿)에서의 철(鐵)의 소실속도(消失速度) 3. 혈장내(血漿內)에서의 철교체율(鐵交替率) 4. 적혈구(赤血球)의 철이용(鐵利用) 5. 생체내(生體內)의 철분포(鐵分布) 6. 철배설(鐵排泄)의 정량적(定量的) 분석(分析) 또한 근년(近年)에는 특수(特殊)한 기능(機能)을 발휘(發揮)할 수 있는 동위원소(同位元素)를 이용(利用)하여 철흡수(鐵吸收) 및 대사이외(代謝以外)에도 적혈구(赤血球)의 수명(壽命)과 혈액량등(血液量等)을 측정(測定)하게 되었다. 경구적(經口的)으로 투여(投與)된 철(鐵)은 대부분(大部分) 십이지장(十二指腸)의 상부(上部)에서 흡수(吸收)되고 무기철(無機鐵)이 보다 쉽게 흡수(吸收)되어 가(價)의 상태(狀態)로 된다. 혈장(血漿)에서는 transferrin에 의(依)해서 철(鐵)이 운반(運搬)된다. 혈장철(血漿鐵)의 대부분(大部分)은 혈색소분해(血色素分解)에서 유래(由來)되며 이는 다시 혈색소(血色素)의 재생(再生)에 이용(利用)되는데 혈장내(血漿內) 철교체율(鐵交替率)은 방사성철(放射性鐵)을 이용(利用)하여 측정(測定)할수 있다 이와같이 방사성철(放射性鐵)을 이용(利用)하여 철대사과정(鐵代謝過程)을 숙지(熟知)함으르서 임상(臨床)에 응용(應用)하기에 이르렀으며 다음과 같은 질환(疾患)의 진단(診斷)에 특(特)히 큰 도움을 준다. A. 진성철결핍증(眞性鐵缺乏症) : 혁색소철(血色素鐵) 및 저장철(貯藏鐵)을 포함(包含)한 생체내(生體內) 전철분(全鐵分)의 부족(不足)된 상태(狀態)로서 실혈(朱血)에 의(依)한 것이 대부분(大部分)이다. 이 경우 철흡수(鐵吸收)는 증가(增加), 혈장철치(血漿鐵値)는 저하(低下), 철소실속도(鐵消失速度)는 증가(增加)되며 혈장철(血漿鐵) 교체율(交替率)은 항진(亢進) 혹(或)은 정상(正常)이다. B. 심(甚)한 염증성(炎症性) 질환(疾患) : 이 경우에도 혈장철치(血漿鐵値)의 저하(低下), 소실속도(消失速度)의 증가(增加), 교체율(交替率)은 정상(正常)보다 4배(倍)까지 증가(增加)할 수 있다. 골수(骨髓)에서 보다는 간(肝), 비(脾)와 같은 망내계(網內系)에 방사성철(放射性鐵)이 집결(集結)되는 것으로 보아 혈색소철(血色素鐵)보다는 저장철(貯藏鐵)이 관여(關與)되는 것이다. C. 원발성(原發性) 혈색소증(血色素症)(Idiopathic hemochromatosis) : 혈장철(血漿鐵)의 증가(增加)가 현저(顯著)하며 transferrin 농도(濃度)는 정상(正常)보다 낮으나 거의 대부분(大部分)의 철분(鐵分)으로 포화(飽和)된다. 철흡수(鐵吸收)는 증가(增加)되고 철소실속도(鐵消失速度)는 감소(減少) 되어 있으나 교체율(交替率)은 항진(亢進)되어 있다. 혈장철(血漿鐵)은 간(肝), 비(脾) 등(等)의 기관(器管)으로 저장집결(貯藏集結)되어 철저류(鐵貯溜)가 증대(增大)되므로 철이용증((鐵利用症)은 저하(低下)된다. D. 선천성(先天性) 무(無)$\ulcorner$트란스헤 린$\lrcorner$증(症)(Congenital atransferrinemia) : 방사성철(放射性鐵)을 이용(利用)한 진단방법(診斷方法)으로 Freiburg에서 7세(歲)의 소녀(少女)에서 발견(發見)한 증례(症例)인데 간(肝), 비(脾), 심(心)의 비대(肥大)가 임상적(臨床的)으로 인지(認知)되었고 중증(重症)의 철결핍상(鐵缺乏狀)을 검출(檢出)할 수 있었다. 철흡수율(鐵吸收率)의 상승(上昇), 혈장철치(血裝鐵値)의 감소(減少), 혈장철소실속도(血漿鐵消失速度)의 증가(增加), 혈장철교체율(血漿鐵交替率)의 상승(上昇) 및 적혈구(赤血球)에서의 철분이용율(鐵分利用率)의 저하(低下)를 ferrokinetic study에서 알 수 있었고 간(肝)에서 고도(高度)의 방사능(放射能)이 검출(檢出)되는 반면(反面), 비(脾)에서는 극소(極小), 골수(骨髓)에는 전(全)혀 방사능(放射能)이 들어가 있지 않았다. 이 증례(症例)와 같이 transferrin이 없으면 철분(鐵分)은 쉽게 조직(組織)으로 들어가 hemosiderin으로 저장(貯藏)되고 골수(骨髓)는 고도(高度)의 철결핍증(鐵缺乏症)을 나타내어 기관철침착증(器管鐵沈着症)과 철결핍성빈혈(鐵缺乏性貧血)이 동시(同時)에 나타나게 된다. 철대사장애면(鐵代謝障碍面)으로 보아 많은 미해결점(未解決點)이 남아 있으며 앞으로 자라나는 젊은 학도(學徒)들이 구명(究明)할 문제(間題)라고 믿는다.

• The Korean Journal of Nuclear Medicine
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• v.38 no.4
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• pp.288-293
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• 2004

Purpose: increased uptake of wrist and hand joints in three phase bone scintigraphy (TPBS) have been used in the detection of reflex sympathetic dystrophy syndrome (RSDS). TPBS frequently shows increased shoulder uptake in the hemiplegic RSDS patients. We investigated the significance of the shoulder uptake in the detection of these patients. Materials and Methods: Twenty three patients who had hemiplegia due to brain stroke and diagnosed as RSD were enrolled in this study (M:F=16:7, R:L=11:12). The mean age was $63{\pm}10$ yrs. Ter normal volunteer (mean age: $60{\pm}5$, M:F=1:9) data was used as control group. TPBS was performed $59{\pm}32$ days after stoke (acute stage). We obtained the count ratios of bilateral hands by drawing a region of interest (ROI) in three phase images and compared to the count ratios of shoulders in the delayed image. Hand ROI included an ipsilateral wrist. Sensitivity of detecting the affected limb was defined using the right/left count ratio of normal control. Results: Sensitivities using count ratios of hand blood flow, blood pool and delayed image were 45%, 76% and 78%, respectively. Sensitivity of shoulder count ratio was 74%. Log of right/left counts of hand delayed image and that of shoulder delayed image were correlated well with statistical significance (Spearman's R=0.824, p<0.001). Conclusion: Shoulder uptake showed good correlation with hand uptake in the delayed image of TPBS. Shoulder uptake maybe helpful in the diagnosis of reflex sympathetic dystrophy syndrome in patients with hemiplegia.

• Progress in Medical Physics
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• v.14 no.4
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• pp.259-267
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• 2003

In vivo $^1$H magnetic resonance spectroscopy (MRS) at 4.7 T was applied to investigate the cerebral metabolite changes of mice brain before and after experimental brain trauma. In vivo $^1$H MR spectra were acquired from a voxel covering right parietal cortex in normal brain, used as control subjects. After experimental brain trauma using the fluid percussion injury (FPI) method, $^1$H MR spectra were acquired from the same lesion three days after trauma. Metabolite ratios of the injured lesion were compared to those of controls. After trauma, N-acetylaspartate (NAA)/creatine (Cr) ratio, as a neuronal marker was decreased significantly versus controls, indicating neuronal loss. The ratio of NAA/Cr in traumatic brain contusion was 0.90$\pm$0.11, while that in normal control subjects was 1.13$\pm$0.12 (P=0.001). Choline (Cho)/Cr ratio had a tendency to rise in experimental brain contusion (P=0.02). Cho/Cr ratio after trauma was 0.91$\pm$0.17 while that before traumas was 0.76$\pm$0.15. Cho/Cr ratio was increased and this might indicate a inflammatory activity. However, no significant difference of [(glutamate＋glutamine) (Glx)]/Cr was established between experimental traumatic brain injury models and normal controls. Lactate (Lac)/Cr ratio was appeared as a sign of shifted posttraumatic energy metabolism and increased versus controls. These findings strongly suggest that in vivo $^1$H MRS may be a useful modality for clinical evaluation of traumatic contusion and could aid in better understanding the neuropathologic process of traumatic contusion induced by FPI. In the present study, in vivo $^1$H MRS was proved to be a useful non-invasive method for in vivo diagnosis and monitoring of posttraumatic metabolism in models of brain contusion.