• Title/Summary/Keyword: Medical radiation

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Biphasic Mechanical Responses of Rat Thoracic Aorta to Irradiation with $250{\sim}500\;nm$ Light (돼지 관상동맥 및 흰쥐 흉부대동맥에서 자외선 및 가시광선 조사시 파장에 따른 기계적 반응과 Cyclic GMP의 농도변화)

  • Kook, Hyun
    • The Korean Journal of Pharmacology
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    • v.31 no.3
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    • pp.285-290
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    • 1995
  • This study was undertaken to define the varying responses of vascular smooth muscle to different wavelengths of ultraviolet radiation and to relate them to the changes in cyclic GMP contents. The ring preparations of rat thoracic aorta with intact or removed endothelium were irradiated with the ultraviolet or visible light (UVR) of wavelengths in step of 10 nm between 250 and 500 nm from xenon lamp of a spectrofluorometer, and the changes in vascular tension were recorded. For cyclic GMP assay, the preparations, pretreated with phenylephrine as in the tension experinents, were frozen after irradiation and homogenated in trichloroacetic acid. The supernatant was extracted with ether and the cyclic GMP contents were measured with radioimmunoassay. In the endothelium-intact preparations, biphasic responses, vasoconstriction (UVR-contraction) followed by vasodilatation (UVR-dilatation), were observed. The maximal UVR-contraction was observed at 320 nm, while the maximal vasodilatation was elicited at 420 nm. In the endothelium-removed rings, however, only vasodilatation was observed, with the maximal vasodilatation taking place at 370 nm. The cyclic GMP contents were not affected by the Irradiation with 320 nm for 30 sec or 1 min in the endothelium-intact preparations, while it was significantly increased by 380 and 420 nm. In the endothelium-removed preparations, UVR of 370 nm markedly increased the cyclic GMP contents. The present study indicates that the increase in cyclic GMP is closely related to vasodilatation induced by UVR of 420 nm in the endothelium-intact or 370 nm in the denuded preparations, whereas it is not involved in the vasoconstriction induced by UVR of 320 nm in the intact rings, and the mechanism leading to UVR-contraction remains to be clarified. These observations suggest that nitric oxide-cyclic GMP system is closely related to the UVR-dilatation in rat aortic preparation, while it is not involved in the UVR contraction.

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Mast Cells are Responsible for Expression of α-Smooth Muscle Actin in Stromal Cells of the Uterine Cervix during Epithelial Neoplastic Changes (자궁경부상피의 악성변화에서 비만세포가 간질세포의 α-Smooth Muscle Actin 발현에 미치는 영향)

  • Jekal, Seung-Joo;Choi, Young-Ja;Lee, Kwang-Joo;Roh, Jong-Sup
    • Korean Journal of Clinical Laboratory Science
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    • v.39 no.3
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    • pp.210-216
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    • 2007
  • There is increasing evidence that stromal reaction in cancer has an important diagnostic and prognostic significance. The aim of our study is to analyze the relation between the increase in mast cell number and the expression CD34 and alpha-smooth muscle actin (${\alpha}$-SMA) in the stroma of cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC). We investigated a total of 29 CIN (1,2,3) and 21 SCC (microinvasive and invasive) specimens and compared the distribution of $CD34^+$ stromal cells, ${\alpha}-SMA^+$ cells, transforming growth factor-${\beta}1$ $(TGF-{\beta}1)^+$ cells, and the density of mast cells using immunohistochemistry with antibodies against CD34, ${\alpha}$-SMA, TGF-${\beta}1$, and c-Kit (CD117) respectively. Computerized image analysis was to evaluate the positive area (%) and density of the respective immunoreactive cells. In CIN $CD34^+$ cells were abundant in the stroma but no ${\alpha}-SMA^+$ cells were identified except the wall of blood vessels. $CD34^+$ cells were progressively decreased along the continuum from CIN 2 to microinvasive SCC and not observed in the stroma of invasive SCC. Whereas ${\alpha}-SMA^+$ cells were only observed in the stroma of microinvasive and invasive SCC. We found more intense TGF-${\beta}1$ expression in the increased mast cells in the stroma of invasive SCCs than that in the stroma of CIN. These results indicate that disappearance of $CD34^+$ stromal cells and appearance of ${\alpha}-SMA^+$ cells are associated with the stromal change of CIN to SCC and the transformation of $CD34^+$ stromal cells into ${\alpha}-SMA^+$ cells is mediated by TGF-${\beta}1$ secretions in the stromal mast cell of SCC.

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Involvement of ROS in Curcumin-induced Autophagic Cell Death

  • Lee, Youn-Ju;Kim, Nam-Yi;Suh, Young-Ah;Lee, Chu-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.1
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    • pp.1-7
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    • 2011
  • Many anticancer agents as well as ionizing radiation have been shown to induce autophagy which is originally described as a protein recycling process and recently reported to play a crucial role in various disorders. In HCT116 human colon cancer cells, we found that curcumin, a polyphenolic phytochemical extracted from the plant Curcuma longa, markedly induced the conversion of microtubule-associated protein 1 light chain 3 (LC3)-I to LC3-II and degradation of sequestome-1 (SQSTM1) which is a marker of autophagosome degradation. Moreover, we found that curcumin caused GFP-LC3 formation puncta, a marker of autophagosome, and decrease of GFP-LC3 and SQSTM1 protein level in GFP-LC3 expressing HCT116 cells. It was further confirmed that treatment of cells with hydrogen peroxide induced increase of LC3 conversion and decrease of GFP-LC3 and SQSTM1 levels, but these changes by curcumin were almost completely blocked in the presence of antioxidant, N-acetylcystein (NAC), indicating that curcumin leads to reactive oxygen species (ROS) production, which results in autophagosome development and autolysosomal degradation. In parallel with NAC, SQSTM1 degradation was also diminished by bafilomycin A, a potent inhibitor of autophagosome-lysosome fusion, and cell viability assay was further confirmed that cucurmin-induced cell death was partially blocked by bafilomycin A as well as NAC. We also observed that NAC abolished curcumin-induced activation of extracelluar signal-regulated kinases (ERK) 112 and p38 mitogen-activated protein kinases (MAPK), but not Jun N-terminal kinase (JNK). However, the activation of ERK1/2 and p38 MAPK seemed to have no effect on the curcumin-induced autophagy, since both the conversion of LC3 protein and SQSTM1 degradation by curcumin was not changed in the presence of NAC. Taken together, our data suggest that curcumin induced ROS production, which resulted in autophagic activation and concomitant cell death in HCT116 human colon cancer cell. However, ROS-dependent activation of ERK1/2 and p38 MAPK, but not JNK, might not be involved in the curcumin-induced autophagy.

Assessment of Discoidal Polymeric Nanoconstructs as a Drug Carrier (약물 운반체로서의 폴리머 디스크 나노 입자에 대한 평가)

  • BAE, J.Y.;OH, E.S.;AHN, H.J.;KEY, Jaehong
    • Journal of Biomedical Engineering Research
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    • v.38 no.1
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    • pp.43-48
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    • 2017
  • Chemotherapy, radiation therapy, and surgery are major methods to treat cancer. However, current cancer treatments report severe side effects and high recurrences. Recent studies about engineering nanoparticles as a drug carrier suggest possibilities in terms of specific targeting and spatiotemporal release of drugs. While many nanoparticles demonstrate lower toxicity and better targeting results than free drugs, they still need to improve their performance dramatically in terms of targeting accuracy, immune responses, and non-specific accumulation at organs. One possible way to overcome the challenges is to make precisely controlled nanoparticles with respect to size, shape, surface properties, and mechanical stiffness. Here, we demonstrate $500{\times}200nm$ discoidal polymeric nanoconstructs (DPNs) as a drug delivery carrier. DPNs were prepared by using a top-down fabrication method that we previously reported to control shape as well as size. Moreover, DPNs have multiple payloads, poly lactic-co-glycolic acid (PLGA), polyethylene glycol (PEG), lipid-Rhodamine B dye (RhB) and Salinomycin. In this study, we demonstrated a potential of DPNs as a drug carrier to treat cancer.

Treatment Outcome and Prognostic Factors of Cushing's Disease in Adults (성인 쿠싱병의 치료성적과 예후인자)

  • Park, Chul-Kee;Hwang, Sung Kyun;Gwak, Ho-Shin;Yoo, Heon;Chung, Young Seob;Paek, Sun Ha;Kim, Dong Gyu;Jung, Hee-Won;Kim, Seong Yeon;Hong, Seung Kuan
    • Journal of Korean Neurosurgical Society
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    • v.29 no.10
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    • pp.1316-1321
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    • 2000
  • Objectives : The authors analyzed the surgical series of Cushing's disease to evaluate the proper treatment policy and to verify the possible prognostic factors. Material and Methods : Of 50 patients diagnosed as Cushing's disease and operated at Department of Neurosurgery of our institute between 1988 and 1999, 48 patients with available medical records were analyzed retrospectively. Mean follow-up period was 48 months(3 to 109 months). Preoperative diagnosis was made after evaluating the patients with multiple-stage endocrinological studies and 31 selective patients were evaluated with inferior petrosal sinus sampling(IPSS). Magnetic resonance imaging(MRI) and/or high resolution computerized tomography(CT) was done in all patients. A total of 51 transsphenoidal adenomectomy(TSA) were performed including 3 revision for initial surgical failure cases. Remission was decided on the basis of both endocrinological criteria and clinical status. Radiation and/or ketoconazole therapy were applied to failed cases. For the verification of prognostic factors, the authors evaluated the statistical significance of multiple variables over remission rate by chi-square test. Result : Sensitivity of IPSS for central localization was 93.5% which was better than that of MRI(87.5%). But for lateralization, it was 72.4% for IPSS versus MRI 90.5%. Success rate of TSA was 82%(42/51) and recurrence rate was 9%(4/48). When including adjuvant treatments for surgically failed cases, overall success rate was 89.6% and all of 3 reoperated cases(TSA) due to recurrence were successful. Significant complication occurred in 7.8%(4/51) after TSA including hypopituitarism, diabetes insipidus, and visual loss. Non-existence of tumor in MRI and prolonged symptom duration(>3 years) were significant prognostic factors. Conclusion : TSA can be considered as initial treatment for Cushing's disease. In surgically failed cases, multiple treatment modality may improve the overall outcome and repeated TSA for recurrent cases seem to provide similar success.

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Evaluation and Experimental Production of Single-Phase Full-wave Rectification Type for X-ray Equipment of High Precision (고정밀도의 단상전파정류형 X선 장치의 제작 및 평가)

  • Han, Dong-Kyoon;Jung, Jae-Eun;Choi, Jun-Gu;Seoun, Youl-Hun;Ko, Shin-Gwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.1
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    • pp.413-419
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    • 2011
  • Diagnosis X-ray equipment localized at 1950's but it is developed suddenly at 1960's with demand together. Manufacture of Diagnostic X-ray equipment is controled by the KS regulation and the Ministry of Health and Welfare because of hazardous element etc. exposure by radiation. Most of diagnostic X-ray equipment ware single phase and three phase full-wave rectification but from 1980's it transforms it was exchanged in inverter type X-ray equipment. Inverter type X-ray equipment produces approximately 50~80% more average photon intensity then single phase full-wave rectification and the accuracy is high. But from a clinic it dose not use because expensive therefor the efficiency improvement of single phase full-wave rectification is necessary. We produced single phase full-wave rectification X-ray equipment control unit, high tension transformer, filament heating transformer, rectification circuit, high tension cable and others and evaluated efficiency, in result which is excellent compare with Rule of Safety Management and KS regulation.

Image Quality Evaluation of Medical Image Enhancement Parameters in the Digital Radiography System (디지털 방사선시스템에서 영상증강 파라미터의 영상특성 평가)

  • Kim, Chang-Soo;Kang, Se-Sik;Ko, Seong-Jin
    • The Journal of the Korea Contents Association
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    • v.10 no.6
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    • pp.329-335
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    • 2010
  • Digital imaging detectors can use a variety of detection materials to convert X-ray radiation either to light or directly to electron charge. Many detectors such as amorphous silicon flat panels, CCDs, and CMOS photodiode arrays incorporate a scintillator screen to convert x-ray to light. The digital radiography systems based on semiconductor detectors, commonly referred to as flat panel detectors, are gaining popularity in the clinical & hospital. The X-ray detectors are described between a-Silicon based indirect type and a-Selenium based direct type. The DRS of detectors is used to convert the x-ray to electron hole pairs. Image processing is described by specific image features: Latitude compression, Contrast enhancement, Edge enhancement, Look up table, Noise suppression. The image features are tuned independently. The final enhancement result is a combination of all image features. The parameters are altered by using specific image features in the different several hospitals. The image in a radiological report consists of two image evaluation processes: Clinical image parameters and MTF is a descriptor of the spatial resolution of a digital imaging system. We used the edge test phantom and exposure procedure described in the IEC 61267 to obtain an edge spread function from which the MTF is calculated. We can compare image in the processing parameters to change between original and processed image data. The angle of the edge with respect to the axes of detector was varied in order to determine the MTF as a function of direction. Each MTF is integrated within the spatial resolution interval of 1.35-11.70 cycles/mm at the 50% MTF point. Each image enhancement parameters consists of edge, frequency, contrast, LUT, noise, sensitometry curve, threshold level, windows. The digital device is also shown to have good uniformity of MTF and image parameters across its modality. The measurements reported here represent a comprehensive evaluation of digital radiography system designed for use in the DRS. The results indicate that the parameter enables very good image quality in the digital radiography. Of course, the quality of image from a parameter is determined by other digital devices in addition to the proper clinical image.

Analysis on characteristics of person with disability using ratio of the lengths of the second to fourth digits (손가락 비율을 이용한 장애인 특성)

  • Kim, Sung-Jin;Shin, Hyun-Uk;Lee, Byong-Sun;Choi, Ji-Won;Choi, Kyounh-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.6
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    • pp.1145-1154
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    • 2012
  • Recent research has been mostly focused on the differences of prenatal sex hormone could affect the ratio of the lengths of the second to fourth digits (2D:4D) as well as the rate of several physiological characteristics. It has been suggested that digit ratios are thought to be associated with either higher prenatal testosterone levels or greater sensitivity to androgens, or both. However, a study of person with disabilities are rare in Korea. The purpose of this study was to compare patterns of the ratio (2D:4D) of the lengths of the second and fourth digits in persons with disabilities and students without disabilities. Also, we empirically analyze the characteristics of persons with disabilities. We found that finger length ratio (2D:4D) of men with disabilities and student without disabilities were lower than women with disabilities and student without disabilities. Therefore, it could be confirmed that finger length ratio (2D:4D) is sexually dimorphic trait. There were no correlations between finger length ratio (2D:4D) and age group in persons with disabilities. Therefore, as with person without disabilities, the 2D:4D ratio was negatively associated with a growth process of persons with disabilities. Finally, There was no difference correlations between finger length ratio (2D:4D) and level of disability in persons with intellectual disabilities. From this, one possible explanation for this is that if finger length ratio (2D:4D) is related to person with disability then current classification of the level of disability deserves further investigation.

A Convergence Study on the Contamination and Disinfection of General X-ray generator Practical Equipment (일반촬영 실습 장비의 오염 및 소독에 관한 융합적 연구)

  • Park, Gyu-Tae;Kim, Dong-Heun;Park, Sang-Hee;Jung, Won-Hee;Kim, So-Yeon;Hong, Hee-Jin;Son, Na-Ra;Nam, Seoul-Hee;Han, Man-Seok
    • Journal of the Korea Convergence Society
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    • v.11 no.1
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    • pp.51-56
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    • 2020
  • It is going to select one X-ray generating device for diagnosis in a radiography laboratory at K university in Gangwon-do to detect bacteria on the surface contamination of tables, IP cassettes, and lead gowns for medical radiation shielding and to inform students of the need for proper disinfection control and hand hygiene. Then disinfection was carried out with tissue, tissue cleaner and 70% alchol and immediately collected with sterile cotton swabs to assess the contamination distribution status and disinfection effects of the surface. The results of measuring the degree of contamination on the surface showed that the largest number of bacteria were detected in Apron, and the evaluation of the disinfection effects according to surface contamination showed a noticeable effect at 70% Alcohol in IP Cassette, and the disinfection effect was the same for Apron. Therefore, in order to prevent bacterial infections among students, basic hand washing and regular disinfection should be performed before the practice to prevent infection.

Assessment of the Correlation for Geometry Transition using Bone Mineral Density in Proximal Femur (골밀도를 이용한 대퇴근위부 형태 변화의 상관관계 평가)

  • Kim, Da-Hye;Ko, Seong-Jin;Kang, Se-Sik;Kim, Jung-Hoon;Kim, Dong-Hyun;Ye, Soo-Young;Kim, Changsoo
    • The Journal of the Korea Contents Association
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    • v.12 no.12
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    • pp.335-344
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    • 2012
  • Osteoporosis is increasing in Korea as it becomes an aging society with the rapid economic growth and the development of medical technology. Osteoporosis also develops due to chemo and radiation therapy of cancer which also increases owing to Westernized diet. Osteoporosis is caused by reduced bone density, has close relationship with the change of geometry of proximal femur, which is a factor of hip fracture risk. The purpose of this study was the analysis of the correlations of osteoporosis and the change of geometry of proximal femur, which was observed according to T-score variance. The 350 male and female patients are chosen from D hospital in Busan, who were classified by age, sex and T-score values (normal, osteopenia, and osteo porosis). The results show that the age and gender have significant difference in the incidence of osteoporosis; the disease classification according to T-score value has significant difference in the geometry of the proximal femur such as Cortical ratio calcar, Cortical ratio shaft, Hip/shaft Angle, Strength index, Section modulus, CSMI, and CSA, and is highly correlated with the incidence of osteoporosis. Therefore, the findings of this research is that the change of the geometry of the proximal femur could be used as an indicator in the diagnosis of osteoporosis, could enhance the accuracy of the diagnosis in the future, and could be used as a clinical predictive factors through the analysis of the correlations of T-score variance and the geometry changes of the proximal femur.