• Title/Summary/Keyword: sensitivity study

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Feasibility Study of the Real-Time IMRT Dosimetry Using a Scintillation Screen (고감도 형광판을 이용한 실시간 선량측정 가능성 연구)

  • Lim Sang Wook;Yi Byong Yong;Ko Young Eun;Ji Young Hoon;Kim Jong Hoon;Ahn Seung Do;Lee Sang Wook;Shin Seong Soo;Kwon Soo-Il;Choi Eun Kyoung
    • Radiation Oncology Journal
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    • v.22 no.1
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    • pp.64-68
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    • 2004
  • Purpose : To study the feasibility of verifying real-time 2-D dose distribution measurement system with the scintillation screen for the quality assurance. Materials and Methods : The water phantom consisted of a scintillation screen (LANEX fast screen, Kodak, USA) that was axially located in the middle of an acrylic cylinder with a diameter of 25 cm. The charge-coupled device (CCD) camera was attached to the phantom In order to capture the visible light from the scintillation screen. To observe the dose distribution In real time, the intensity of the light from the scintillator was converted to a dosage. The isodose contours of the calculations from RTP and those of the measurements using the scintillation screen were compared for the arc therapy and the Intensity modulated radiation therapy (IMRT). Results : The kernel, expressed as a multiplication of two error functions, was obtained in order to correct the sensitivity of the CCD of the camera and the scintillation screen. When comparing the calculated isodose and measured isodose, a discrepancy of less than 8 mm in the high dose region was observed. Conclusion : Using the 2-D dosimetry system, the relationship between the light and the dosage could be found, and real-time verification of the dose distribution was feasible.

Acupuncture for Prehypertension and Stage 1 Hypertension in Postmenopausal Women: Protocol for a Randomized Controlled Pilot Trial (폐경 후 여성의 전단계 및 1기 고혈압에 대한 침 치료: 다기관 무작위 대조 예비연구)

  • Kim, Jung-Eun;Choi, Jin-Bong;Kim, Hyeong-Jun;Kang, Kyung-Won;Liu, Yan;Jung, Hee-Jung;Lee, Min-Hee;Shin, Mi-Suk;Kim, Jae-Hong;Choi, Sun-Mi
    • Korean Journal of Acupuncture
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    • v.31 no.1
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    • pp.5-13
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    • 2014
  • Objectives : This study aims to evaluate the effectiveness and safety of acupuncture and explore the appropriate number of treatment for postmenopausal women diagnosed with prehypertension and stage 1 hypertension. Methods : A 4-arm randomized open label pilot trial will be performed at 2 centers. Sixty participants will be divided into 2 treatment groups and 2 control groups. Treatment groups will receive acupuncture at 8 points(bilateral GB20, LI11, ST36, SP6) for 4 weeks(treatment group A, 10 total sessions) or 8 weeks(treatment group B, 20 total sessions), while maintaining usual care. Control groups will not receive acupuncture but will be under usual care for 16 weeks(control group C) or 20 weeks(control group D). Each patient's living habits will be corrected and drugs that may affect blood pressure(BP) will be prohibited. Treatment group A and control group C will be evaluated at 4, 8, 12, and 16 weeks after randomization, while treatment group B and control group D will be evaluated at 4, 8, 12, 16, and 20 weeks after randomization. The major outcome variable is the magnitude of change in diastolic BP levels at 4 weeks after randomization; auxiliary outcome variables are (1) diastolic BP change at 8, 16, and 20 weeks, (2) systolic BP change, (3) BP control rate, (4) lipid profiles, and (5) high-sensitivity C-reactive protein. Patient safety will be assessed at every visit. Results and Conclusions : The study findings may help develop evidence for the effectiveness and safety of acupuncture for BP control.

Evaluation of an ELISA kit for the Serodiagnosis of Pulmonary Tuberculosis by Using Mixed Antigens of Mycobacterium Tuberculosis (폐결핵진단에서 결핵균 혼합항원을 이용한 혈청학적 검사의 유용성에 관한연구)

  • Park, Seung-Kyu;Kim, Phil-Ho;Kim, Seung-Chul;Choi, In-Hwan;Cho, Sang-Nae;Song, Sun-Dae
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.5
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    • pp.558-567
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    • 2000
  • Background : Recently, serologic techniques for tuberculosis have been developed and some of them, which are focusing on detection of serum antibodies mainly directed against specific 38-kDa Mycobacterium tuberculosis, have already been introduced into the markel. In this study, diagnostic significance of a new serologic test(ELISA kit) for pulmonary tuberculosis was evaluated. Method : Serologic test with newly developed ELISA kit was performed upon 474 individuals, who include 333 active pulmonary tuberculosis patients, 80 healthy cases, and 61 tuberculosis contact cases. This serologic test was based on the ELISA technique and designed to detect antibodies to mixed complex antigens including 38-kDa, which were developed by Erume Biotech Co., Seoul. Active pulmonary tuberculosis was diagnosed by sputum AFB smear and culture methods. Results : The seropositivities using this ELISA kit were 82.1% and 73.6% in smear-positive and negative groups among active pulmonary tuberculosis, respectively. And, it also showed that seronegativities were 97.5% and 85.2% in healthy and contact groups, respectively. As a whole, the results of our study using the ELISA kit as a diagnostic method for pulmonary tuberculosis showed 80.0% sensitivity for active pulmonary tuberculosis, 97.5% specificity, 96.1% positive predictive value, and 65.0% negative predictive value when the prevalence of tuberuclosis in the samples was 60.1%. Conclusion : Our results reveal that the detection of antibody its reaction with 38-kDa antigen of M. tuberculosis is not sufficient to be accepted as single diagnostic method for pulmonary tuberculosis. However, they suggest that ELISA kit may be considered as an adjunctive test to standard diagnostic techniques of pulmonary tuberculosis.

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Clinical Significance of PCR-Based Rapid Detection of Mycobacterium tuberculosis DNA in Peripheral Blood (결핵 환자에서 말초혈액 결핵균 중합효소 연쇄반응 양성의 임상적 의의)

  • Kim, Gyu-Won;Lee, Jae-Myung;Kang, Min-Jong;Son, Jee-Woong;Lee, Seung-Joon;Kim, Dong-Gyu;Lee, Myung-Goo;Hyun, In-Gyu;Jung, Ki-Suck;Lee, Young-Kyung;Lee, Kyung-Wha
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.5
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    • pp.599-606
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    • 2001
  • Background : Since the advent of AIDS, tuberculosis has become a major public health problem in the western society. Therefore, it is essential that pulmonary tuberculosis be rapidly diagnosed. Light microscopic detection of acid-fast organisms in sputum has traditionally been used for rapidly diagnosing tuberculosis. However positive smears are only observed in about one-half to three-quarters of cases. Studies using PCR for diagnosing pulmonary tuberculosis disclosed several shortcomings suggesting an inability to distinguish between active and treated or inactive tuberculosis. In this study, the clinical significance of a PCR-based rapid technique for detecting Mycobacterium tuberculosis DNA in peripheral blood was investigated. Materials and Methods : From July 1, 1998 through to August 30, 1999, 59 patients with presumed tuberculosis, who had no previous history of anti-tuberculosis medication use within one year prior to this study were recruited and followed up for more than 3 months. AFB stain and culture in the sputum and/or pleural fluids and biopsies when needed were performed. Blood samples from each of the 59 patients were obtained in order to identify Mycobacterium Tuberculosis DNA by a PCR test. Results : 1) Forty five out of 59 patients had a final diagnosis of tuberculosis ; Twenty eight were confirmed as having active pulmonary tuberculosis by culture or biopsy. Four were clinically diagnosed with pulmonary tuberculosis. The other 13 patients were diagnosed as having tuberculous pleurisy (9) and extrapulmonary tuberculosis (4). 2) Fourteen patients showed a positive blood PCR test. The PCR assay correctly identified active tuberculosis in 13 out of 14 patients. The overall sensitivity and specificity of this blood peR assay for diagnosing tuberculosis were 29% and 93%, respectively. The positive predictive value was 93%, the negative predictive value was 29% and the diagnostic accuracy was 44%.3) Six out of 14(43%) patients with blood PCR positive tuberculosis were immunologically compromised hosts. 4) A simple chest radiograph in blood PCR positive tuberculosis patients showed variable and inconsistent findings. Conclusion : A peripheral blood PCR assay for Mycobacterium tuberculosis is not recommended as a screening method for diagnosing active tuberculosis. However, it was suggested that the blood PCR assay could contribute to an early diagnostic rate due to its high positive predictive value.

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The Role of MnSOD in the Mechanisms of Acquired Resistance to TNF (TNF에 대한 내성획득에서 MnSOD의 역할에 관한 연구)

  • Lee, Hyuk-Pyo;Yoo, Chul-Gyu;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.6
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    • pp.1353-1365
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    • 1997
  • Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. However, since the efficiency of current techniques of gene transfer is not satisfactory, the majority of current protocols is aiming the in vitro gene transfer to cancer cells and re-introducing genetically modified cancer cells to host. In the previous study, it was shown that TNF-sensitive cancer cells transfected with TNF-$\alpha$ cDNA would become highly resistant to TNF, and the probability was shown that the acquired resistance to TNF might be associated with synthesis of some protective protein. Understanding the mechanisms of TNF -resistance in TNF-$\alpha$ cDNA transfected cancer cells would be. an important step for improving the efficacy of cancer gene therapy as well as for better understandings of tumor biology. This study was designed to evaluate the role of MnSOD, an antioxidant enzyme, in the acquired resistance to TNF of TNF-$\alpha$ cDN A transfected cancer cells. Method : We transfected TNF-$\alpha$ c-DNA to WEHI164(murine fibrosarcoma cell line), NCI-H2058(human mesothelioma cell line), A549(human non-small cell lung cancer cell line), ME180(human cervix cancer cell line) cells using retroviral vector(pLT12SN(TNF)) and confirm the expression of TNF with PCR, ELISA, MIT assay. Then we determined the TNF resistance of TNF-$\alpha$ cDNA transfected cells(WEHI164-TNF, NCIH2058-TNF, A549-TNF, ME180-TNF) and the changes of MnSOD mRNA expressions with Northern blot analysis. Results : The MnSOD mRNA expressions of parental cells and genetically modified cells of WEHI164 and ME180 cells(both are naturally TNF sensitive) were not significantly different The MnSOD mRNA expressions of genetically modified cells of NCI-H2058 and A549(both are naturally TNF resistant) were higher than those of the parental cells, while those of parental cells with exogenous TNF were also elevated. Conclusion : The acquired resistance to TNF after TNF-$\alpha$ cDNA transfection may not be associated with the change in the MnSOD expression, but the difference in natural TNF sensitivity of each cell may be associated with the level of the MnSOD expression.

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Analysis of Causes for Primary Treatment Failure of Pulmonary Tuberculosis (폐결핵환자에서 초치료실패에 대한 요인 분석)

  • Park, Seung-Kyu;Choi, In-Hwan;Kim, Cheon-Tae;Song, Sun-Dae
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.6
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    • pp.1234-1244
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    • 1997
  • Background : Nowadays drug resistant tuberculosis is making problems in the treatment of pulmonary tuberculosis and its number is increasing. Several reasons for this are considered including irregular medication, poor drug compliance and wrong regimens. But there are treatment failure cases in spite of regular medication with short-term standard regimens. We reviewed clinical data of 50 patients to find out possible causes of this. Method : Subject of this study was 50 patients who failed in the primary treatment of pulmonary tuberculosis in spite of regular medication with short-term standard regimens. All of them were under treatment with secondary regimens in National Masan Tuberculosis Hospital on Oct 1996. The patient's records were analyzed retrospectively and direct interviews with patients were done. Results : There were relatively more patients in the age of 20th. Male overwhelmed in number. There were smoking in 22 patients and drinking in 24 patients during medication. 17(34%) patients had family history of tuberculosis. Public health center was the most common site for the initial diagnosis among medical institutes. 42 patients had subjective symptoms for pulmonary tuberculosis. 38 patients got sufficient explanation from medical institute about tuberculosis and medication courses. 24 patients had bilateral lesions on chest X-ray film and 43 patients had cavitary lesions. 29 patients had past history for pulmonary tuberculosis with regular medication. The results of drug sensitivity test showed resistance in 41 patients of whom we could get the results. Conclusion : Main cause of treatment failure of pulmonary tuberculosis in spite of regular medication with short-term standard regimens was drug resistance. Several factors were considered to be related to high prevalence of drug resistance, including age of 20th, male, family history for tuberculosis, bilateral lesions or remaining cavitary lesion on chest X-ray film.

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A Study on the DC Resistivity Method to Image the Underground Structure Beneath River or Lake Bottom (하저 지반특성 규명을 위한 수상 전기비저항 탐사에 관한 연구)

  • Kim Jung-Ho;Yi Myeong-Jong;Song Yoonho;Choi Seong-Jun;Lee Seoung Kon;Son Jeong-Sul;Chung Seung-Hwan
    • Geophysics and Geophysical Exploration
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    • v.5 no.4
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    • pp.223-235
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    • 2002
  • Since weak Bones or geological lineaments are likely to be eroded, there may develop weak Bones beneath rivers, and a careful evaluation of ground condition is important to construct structures passing through a river. DC resistivity method, however, has seldomly applied to the investigation of water-covered area, possibly because of difficulties in data aquisition and interpretation. The data aquisition having high quality may be the most important factor, and is more difficult than that in land survey, due to the water layer overlying the underground structure to be imaged. Through the numerical modeling and the analysis of a case history, we studied the method of resistivity survey at the water-covered area, starting from the characteristics of measured data, via data acquisition method, to the interpretation method. We unfolded our discussion according to the installed locations of electrodes, ie., floating them on the water surface, and installing them at the water bottom, because the methods of data acquisition and interpretation vary depending on the electrode location. Through this study, we could confirm that the DC resistivity method can provide fairly reasonable subsurface images. It was also shown that installing electrodes at the water bottom can give the subsurface image with much higher resolution than floating them on the water surface. Since the data acquired at the water-covered area have much lower sensitivity to the underground structure than those at the land, and can be contaminated by the higher noise, such as streaming potential, it would be very important to select the acquisition method and electrode array being able to provide the higher signal-to-noise ratio (S/N ratio) data as well as the high resolving power. Some of the modified electrode arrays can provide the data having reasonably high S/N ratio and need not to install remote electrode(s), and thus, they may be suitable to the resistivity survey at the water-covered area.

Antibiotic Susceptibility of Bacteria Isolated from Infected Root Canals (감염근관에서 분리 배양한 세균의 수종 항생제에 대한 감수성 조사)

  • Lim, Sang-Soo;Kim, Mi-Kwang;Min, Jeong-Beom;Kim, Min-Jung;Park, Soon-Nang;Hwang, Ho-Keel;Kook, Joong-Ki
    • Korean Journal of Microbiology
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    • v.42 no.3
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    • pp.185-194
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    • 2006
  • The aim of this study was to identify the bacteria isolated from endodontic lesions by cell culture and to determine the antimicrobial susceptibility of them against 8 antibiotics. The necrotic pulpal tissues were collected from 27 infected root canals, which were diagnosed as endodontic infection. Samples were collected aseptically from the infected pulpal tissue of the infected root canals using a barbed broach and a paper point. The cut barbed broaches and paper points were transferred to an eppendorf tube containing $500{\mu}l\;of\;1{\times}PBS$. The sample solution was briefly mixed and plated onto a BHI-agar plate containing 5% sheep blood. The agar plates were incubated in a $37^{\circ}C$ anaerobic chamber for 2 to 5 days. The bacteria grown on the agar plates were identified by comparison of 16S rRNA gene (rDNA) sequencing method at the species level. To test the sensitivity of the bacteria isolated from the infected root canals against 8 antibiotics, minimum inhibitory concentrations (MIC) were determined using broth dilution assay. The data showed that 101 bacterial strains were isolated and were identified. Streptococcus spp. (29.7%) and Actinomyces spp. (21.8%) were predominantly isolated. The 9 strains were excluded in antimicrobial susceptibility test because they were lost during the experiment or were not grown in broth culture. The percentage of bacteria susceptible for each antibiotic in this study was clindamycin, 87.0% (80 of 92); tetracycline, 75.0% (69 of 92); cefuroxime axetil, 75.0% (69 of 92); amoxicillin + clavulanic acid (5:1), 71.7% (66 of 92); penicillin G, 66.3% (61 of 92); erythromycin, 66.3% (61 of 92); amoxicillin, 44.6% (41 of 92); and ciprofloxacin, 31.5% (29 of 92). The susceptibility pattern of 8 antibiotics was dependent on the host of the bacteria strains rather than the kinds of bacterial species. These results indicate that antibiotic susceptibility test should be performed when antibiotics are needed for the treatment of infected root canals.

The Diagnostic Utility of PET-CT for the Preoperative Evaluation of Lymph Node Metastasis in Gastric Cancer Patients (위암 환자의 수술 전 림프절 전이 평가를 위한 PET-CT의 진단적 유용성)

  • Park, Sung-Hyuk;Cho, Min-Su;Ryu, Hoon;Bae, Keum-Seok;Kim, Ik-Yong;Kim, Dae-Sung
    • Journal of Gastric Cancer
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    • v.8 no.4
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    • pp.250-255
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    • 2008
  • Purpose: The purpose of this study was to assess the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for detecting the lymph node (LN) metastasis of gastric cancer. Materials and Methods: 119 patients (M : F=89 : 30; mean age: 64) with gastric cancer were referred for preoperative FDG-PET/CT scanning and spiral enhanced abdominal pelvic CT from June 2006 to July 2008, and these were the subjects of our study. All the patients underwent curative radical gastrectomy and lymph node dissection. A final diagnosis was made for all the patients by the histology of the surgical specimens. Results: Both PET/CT and enhanced CT showed similar sensitivity for detecting regional lymph node metastasis (32.6% vs 39.5%, respectively). PET/CT was more accurate than enhanced CT for detecting regional lymph node metastasis (67.2% vs 63.0%, respectively), and PET/CT showed better specificity (86.8% vs 76.3, respectively) and a better positive predictive value (PPV) (58.3% vs 48.6%, respectively). PET/CT showed better specificity (98.0% vs 88.2%, respectively) and accuracy (79.4% vs 73.9%, respectively) than enhanced CT for detecting early gastric cancer. PET/CT showed better specificity (64.0% vs 52.0%, respectively), a better PPV (60.9% vs 57.1%), a better negative predictive value (NPV) (48.5% vs 46.4%, respectively) and better accuracy (53.6% vs 51.8%, respectively) than enhanced CT for detecting advanced gastric cancer. Conclusion: FDG-PET/CT is more usefulness than enhanced CT for making the preoperative diagnosis of regional LN metastases from gastric cancers.

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A Study on the Experience Design and Practical Use of Experience by On- and Off-Line Environment (온 오프라인 환경에 따른 경험의 활용과 경험디자인에 관한 연구)

  • Yoon, Se-Kyun;Kim, Tae-Kyun;Kim, Min-Su
    • Archives of design research
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    • v.18 no.3 s.61
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    • pp.5-14
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    • 2005
  • In the past, consumers sought utilitarian and defensive consumption in an attempt to move to a balanced state. However, today's consumers go beyond this to consume more for hedonic and creative reasons if not for sheer pleasure. There is an obvious shift from the type of consumption that satisfies basic desires through the characteristics, convenience and quality of goods and services to an era of 'experiential consumption,' in which consumers pursue distinctive value systems and way of life along with a total 'experience' provided by such goods and services. Such a sign of the times has given birth to the experience design that aims at maximizing the strategic use of experiences in design. Research on this subject is gradually increasing. The research and application peformed even without the proper understanding about the concepts and purposes of experience design, however, is likely to deviate from the true nature in its process or method. Also, they are likely to cause rather than solve problems. Accordingly, this study examined the meaning of experience from a spatial aspect, focusing on areas that recognize the experience as economically valuable, making the most of it substantively. The main concept of experience practical used on-line is enhancement of the usability of a medium by reflecting the experience of users accustomed to both off-line and on-line environments and materializing the environment doser to and more familiar with the users, thus allowing them to comfortably use the medium. This is to allow the users to feel more comfortable. The experience practical used pertaining to off-line is a tool to fulfill the sensitivity of users, with efforts to create new, future-oriented consumer values. This, based on the understanding of consumer behavior, seeks to maximize the consumption experience of consumers by providing a combination of sensual and sensitive experiences as well as to enhance the existing experiences by permitting users to create new, extended experiences from the fixed characteristics of products. Furthermore, it aims to provide consumers with the hedonic experience of play through the joy, fun and uniqueness of alternate experiences.

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