• Radiation Oncology Journal
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• v.16 no.3
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• pp.351-355
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• 1998

Cutaneous angiosarcomas are uncommon malignancies which account about 1$\%$ of sarcomas. They are found most commonly in the head and neck regions, frequently on the scalp. Although preferred treatment has been combined surgery and postoperative radiation therapy, the extensiveness and multiplicity of the lesions set limits to such an approach and the patient is often referred for radiotherapy without surgery. As the entire scalp usually needs to be treated, radiation therapy is a challenging problem to radiation oncology staffs. We report a case of angiosarcoma of the scalp, which was treated successfully by radiation therapy with a simple and repeatable method using mixed Photon and electron beam technique. Using a bolus to increase the surface dose of the scalp and to minimize dose to the normal tissues of the brain desirable but difficult technically to be well conformed to the three dimensional curved surface such as vertex of the head. A helmet made of thermoplastics filled with paraffin was elaborated and used for the treatment, resulting of the relatively uniform surface doses along the several points measured on the scalp, the difference among the points not exceeding 7$\%$ of the prescribed dose by TLD readings.

• Journal of radiological science and technology
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• v.42 no.5
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• pp.351-356
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• 2019

This study aimed to determine whether there was a difference in measurements between North American Symptomatic Carotid Endarterectomy Trial(NASCET) and Warfarin-Aspirin Symptomatic Intracranial Disease(WASID) methods that measure the middle cerebral artery stenosis in Digital Subtraction Angiography (DSA) and Magnetic Resonance Angiography (MRA). It involved 24 patients who had completed both DSA and MRA among patients with Middle Cerebral Artery (MCA) stenosis. The Middle Cerebral Artery (MCA) stenosis was measured using the NASCET and WASID methods through a retrospective analysis. For the NASCET and WASID methods, they performed measurements on normal blood vessels located far from and close to the stenosis, respectively. The mean value and standard deviation of the Digital Subtraction Angiography (DSA) measured by the NASCET method were 59.23% and 13.27%. On the other hand, those of the Digital Subtraction Angiography (DSA) measured by the WASID method were 66.64% and 12.47%. And, the mean value and standard deviation of the Magnetic Resonance Angiography (MRA) measured by the NASCET method were 49.82% and 12.06%. By contrast, those of the Magnetic Resonance Angiography (MRA) measured by the WASID method were 56.63% and 10.67%. All the p-values obtained by the Pearson and Spearman correlation tests in the Digital Subtraction Angiography (DSA) and the Magnetic Resonance Angiography (MRA) were <0.01. In conclusion, this study suggests that both the NASCET and WASID methods to measure the middle cerebral artery stenosis in the Digital Subtraction Angiography (DSA) and the Magnetic Resonance Angiography (MRA) can be used if they are not used interchangeably.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.2
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• pp.51-56
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• 2021

The brachial systolic blood pressure and pulse pressure are the predictors of cardiovascular disease in individuals over 50 years of age. As the stiffness increases, the reflex amplitude and pressure in the late systole increase, resulting in an increase in left ventricular load and myocardial oxygen demand. Therefore, it is necessary to study how stiffness affects blood pressure. In this study, the blood pressure pulse waves were measured before and after taking the drug, and the blood pressure pulse wave was measured before and after myocardial heart transplantation in patients with heart failure. The correlation between R, L, and C components of the Windkessel model was estimated by increasing blood pressure. As a result of modeling the parameters of the Windkessel model using the curve fitting method, the increase in blood pressure and decrease in systolic rise time were due to the increase in the L component in the RLC Windkessel model. Among the various mechanical characteristics of blood vessels, the most important parameter affecting high BP waveform is the inertance.

• The Korean Journal of Nuclear Medicine
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• v.33 no.6
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• pp.475-483
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• 1999

Purpose: Complete fibrovascular ingrowth within the hydroxyapatite ocular implant is necessary for peg drilling which is performed to Prevent infection and to provide motility to the ocular prosthesis. We compared planar bone scintigraphy and SPECT for the evaluation of the vascularization within hydroxyapatite ocular implants. Materials and Methods: Seventeen patients (M:F: 12:5, mean age; $50.4{\pm}17.5$ years) who had received a coralline hydroxyapatite ocular implant after enucleation surgery were enrolled. Patients underwent Tc-99m MDP planar bone and SPECT imaging by dual head gamma camera after their implant surgery (interval: $197{\pm}81$ days). Uptake on planar and SPECT images was graded visually as less than (grade 1), equal to (grade 2), and greater than (grade 3) nasal bridge activity. Quantitative ratio of implanted to non-implanted intraorbital activity was also measured. Vascularization within hydroxyapatite implants was confirmed by slit lamp examination and ocular movement. Results: All but three patients were considered to be vascularized within hydroxyapatite implants. In visual analysis of planar image and SPECT, grade 1 was noted in 9/18 (50%) and 6/18 (33%), respectively. Grade 2 pattern was 7/18 (39%) and 4/18 (22%), and grade 3 pattern was 2/18 (11%) and 8/18 (44%) respectively. When grade 2 or 3 was considered to be positive for vascularization, the sensitivity of planar and SPECT imaging were 60% (9/15) and 80% (12/15), respectively. In 3 patients with incomplete vascularization, both planar and SPECT showed grade 1 uptake The orbital activity ratios on planar imaging were not significantly different between complete and incomplete vascularization ($1.96{\pm}0.87$ vs $1.17{\pm}0.08$, p>0.05), however, it was significantly higher on SPECT in patients with complete vascularization ($8.44{\pm}5.45$ vs $2.20{\pm}0.87$, p<0.05). Conclusion: In the assessment of fibrovascular ingrowth within ocular implants by Tc-99m MDP bone scintigraphy, SPECT image appears to be more effective than planar scintigraphy.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1401-1402
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• 2015

급작스레 발병하는 혈관 질환으로 인해 실시간 혈압 추정 연구가 많이 진행되어지고 있다. 본 논문에서는 자기장을 이용하여 혈압을 추정할 수 있는 자계용적맥파 시스템을 개발하였다. 자기장을 이용한 방법은 온도에 강하며 혈류와 상관성이 있기에 사용하였다. 혈압 추정의 과정은 총 3부분 나눌 수 있다. MPG측정, ECG측정 그리고 신호처리 부분이며 신호처리는 PC에서 디지털 필터링 및 PTT 계산을 실시하게 된다. 비교 기준 혈압으로 Omron 혈압계를 사용하여 동시 측정하였으며 결과로 각 PTT간 기준 수축기 및 이완기 혈압을 비교 할 수 있었다.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.599-604
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• 2004

Implantable flexible sensor using polymer/metal multilayer processing technique for telemetrical real-time blood pressure monitoring is presented. The realized sensor is mechanically flexible, which can be less invasively implanted and attached on the outside of blood vessel to monitor the variation of blood pressure. Therefore, unlike conventional detecting methods which install sensor on the inside of vessel, the suggested monitoring method can monitor the relative blood pressure without injuring blood vessel. The major factor of sudden death of adults is a disease of artery like angina pectoris and myocardial infarction. A disease of circulatory system resulted from vessel occlusion by plaque can be preventable and treatable early through continuous blood pressure monitoring. The procedure of suggested new method for monitoring variation of blood pressure is as follows. First, integrated sensor is attached to the outer wall of blood vessel. Second, it detects mechanical contraction and expansion of blood vessel. And then, reader antenna recognizes it using telemetrical method as the relative variation of blood pressure. There are not any active devices in the sensor system; therefore, the transmission of energy and signal depends on the principle of mutual inductance between internal antenna of LC resonator and external antenna of reader. To confirm the feasibility of the sensing mechanism, in vitro experiment using silicone rubber tubing and blood is practiced. First of all, pressure is applied to the silicone tubing which is filled by blood. Then the shift of resonant frequency with the change of applied pressure is measured. The frequency of 2.4 MHz is varied while the applied pressure is changed from 0 to 213.3 kPa. Therefore, the sensitivity of implantable blood pressure is 11.25 kHz/kPa.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.4
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• pp.21-26
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• 2011

Feature ranking is useful to gain knowledge of data and identify relevant features. In this study, we proposed a use of feature ranking for classification of neuro-degeneration and vascular dementia in micro-Raman spectra of platelet. The entire region of the spectrum is divided into local region including several peaks, followed by Gaussian curve fitting method in the region to be modeled. Local minima select from the subregion and then remove the background based on the position by using interpolation method. After preprocessing steps, significant features were selected by feature ranking method to improve the classification accuracy and the computational complexity of classification system. PCA (principal component analysis) transform the selected features and the overall features that is used classification with the number of principal components. These were classified as MAP (maximum a posteriori) and it compared with classification result using overall features. In all experiments, the computational complexity of the classification system was remarkably reduced and the classification accuracy was partially increased. Particularly, the proposed method increased the classification accuracy in the experiment classifying the Parkinson's disease and normal with the average 1.7 %. From the result, it confirmed that proposed method could be efficiently used in the classification system of the neuro-degenerative disease and vascular dementia of platelet.

• Applied Microscopy
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• v.35 no.4
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• pp.55-63
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• 2005

The characteristics of primary cultured rat brain microvessel endothelial cells (RBMECs) were studied using microscopy, immunohistochemistry and measuring of transendothelial electrical resistance (TER). The RBMECs formed a monolayer by $5{\sim}6$ days after plating and showed characteristics of whirling appearance. The TER increased until day 5 and decreased then. There was few immunoreaction with anti-GFAP, anti-GalC, anti-neurofilament 160/200 kD antibodies. So the contamination of astrocyte, oligodendrocyte, and neuron. could be ruled out.. Immunoreaction to vWF antigen was widespread througout the cytoplasm as Weibel-Palade granule. Immunoreaction to tight junction proteins, i.e. occludin, ZO-1, and ZO-2 was seen at cell contact. In summary, RBMECs isolated and cultured showed morphological, immunohistochemical and electrical characteristics of blood-brain barrier (BBB). The in vitro BBB model can be used in studying characteristics of in vivo BBB.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.323-331
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• 1995

Monocyte/macrophage infiltration is the well known initial features associated with the development of glomerular disease including non-immune mediated nephropathy. Tumor necrosis factor ${\alpha}(TNF{\alpha})$, a cytokine produced primarily by monocyte/macrophage, exhibits similar effects as observed at the initial stages and during the progression of glomerular injury. Because the mesangial cells are target cells for glomerular injury, the present study examined the effect of $TNF{\alpha}$ on glomerular mesangial cell membrane lipid peroxidation as an index of cytotoxicity attributing to $TNF{\alpha}$. Primary culture of rat mesangial cell was established by incubation of glomeruli isolated from male Sprague-Dawley rat kidneys utilizing a standard sieving method. The levels of lipid peroxides in the mesangial cells were quantitated by malondialdehyde- thiobarbituric acid adduct formation. During an 8 hour incubation at $37^{\circ}C$, $TNF{\alpha}$ at 10 to 10,000 units/ml increased the levels of lipid peroxides dose dependently. Western blot analysis demonstrated that a short thermal stress induced heat shock response and the synthesis of heat shock protein 70(hsp70) in this mesangial cells. Further, this induction of hsp 70 prevented increase of lipid peroxides in the mesangial cells exposed to $TNF{\alpha}$. These data suggest that $TNF{\alpha}-induced$ lipid peroxidation in the mesangial cells may have pathophysiological relevance to glomerular injury and prior induction of heat shock response may play a role in the cellular resistance against $TNF{\alpha}-induced$ glomerular injury.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.199-208
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• 2017

Both cardiovascular diseases caused by decreased body composition and arterial compliance and falling induced by loss of muscle mass are frequent occurrences in the elderly. Therefore, elderly people are advised to perform elastic band resistance exercises to improve their body composition and arterial compliance. Thus, the purpose of this study was to examine the effects of 12 weeks of elastic band resistance training on the body composition, arterial compliance and falling index in elderly females (> 65 years). The elastic band resistance exercise program was administered 3 times per week for 60 minutes each time for 12 weeks. In addition, the exercise intensity was set to 11-14 on the Borg scale (6-20). Before and after the training period, the body composition (body weight (BW), muscle mass, % body fat, body mass index (BMI)), arterial compliance (ankle brachial index (ABI) and pulse wave velocity (PWV)) and risk of falling index were determined. (After the program?), the BW (p=.003), BMI (p=.002), PWV (p=.017) and risk of falling (p=.037) in the exercise group were significantly reduced, whereas the BW (p=.009) and BMI (p=.009) in the control group were significantly increased. In conclusion, the body weight, BMI and arterial compliance of elderly females were positively changed by the elastic band resistance training. Thus, the elastic band resistance exercise may be useful for elderly people to prevent metabolic syndrome and cardiovascular diseases and to reduce their risk of falling.