• 제목/요약/키워드: False-negative results

검색결과 302건 처리시간 0.024초

Polymerase Chain Reaction (PCR)을 이용한 결핵의 진단에 관한 연구 (Application of Polymerase Chain Reaction (PCR) to the Diagnosis of Tuberculosis)

  • 김호중;김영환;한성구;심영수;김건열;한용철
    • Tuberculosis and Respiratory Diseases
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    • 제39권6호
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    • pp.517-525
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    • 1992
  • 연구배경 : 1985년 Saiki등에 의해, 특정한 DNA를 연속적으로 복제할 수 있는 방법인 polymerase chain reaction (PCR)이 개발된 이래, PCR은 검체내에 극미량으로 존재하고 있는 병원체의 진단에 큰 도움을 줄 것으로 기대되었다. 결핵균의 진단방법중, 도말염색 방법은 감수성이 낮아서 문제가 되고 있으며, 배양은 감수성은 높으나 기간이 오래 걸려서 임상적으로 도움을 주지 못하는 경우가 많다. 이에 저자들은 Mycobacterium tuberculosis의 특이 단백질인 65 kD mycobacterial antigen을 encoding하는 2520 base pair DNA중, 383 base pair DNA를 이용한 PCR과 IS6110 fragment의 일부인 123 base pair DNA를 이용한 PCR을 시행하여, 이의 감수성과 특이도를 알아보고 폐결핵 환자의 객담을 검체로한 결핵의 조기진단 방법을 개발하고자 하였다. 방법 : M. tuberculosis (H37Rv, H37Ra), M. avium, M. intracellulare, M. scrofulaceum 균주와 환자의 객담에서 DNA를 추출하여, 383 base pair DNA 양끝의 20 base pair DNA primer (TB-1, -2)와 IS6110 fragment 일부의 DNA 양끝의 20 base pair DNA primer (Sal I-1, -2) 로 PCR을 시행하였으며, 전기 영동후 자외선 발광으로 확인하였다. 결과 : 1) Ethidium bromide 염색후 발광경하에서, Mycobacterium tuberculosis (H37Rv, H37Ra)와 Mycobacterium bovis는 TB-1, -2 primer와 Sal I-1, -2 primer를 이용한 PCR에서 모두 양성을 보였고 Mycobacter intracellulare와 Mycobacterium scrofulaceum은 TB-1, -2 primer를 이용한 PCR에서만 양성을 보였다. 2) Southern Blot 분석에는 두쌍의 primer 모두에서 Mycobacterium tuberculosis (H37Rv, H37Ra)와 Mycobactgerium bovis만이 양성을 나타내었으며 Mycobacterium intracellulare 와 Mycobacterium scrofulaceum은 음성을 나타내었다. 3) Mycobacterium tuberculosis (H37Rv)를 순차적으로 희석하여 시행한 PCR에서 두쌍의 primer 모두에서 Mycobacterium 균 1개체에 해 당되는 1 fg DNA까지 양성을 나타내었다. 4) 임상적으로 진단받은 결핵환자의 시행한, Sal I-1, -2 primer를 이용한 PCR에서 도말 검경 양성군의 객담 29예중 28예인 96.6%에서 양성을 나타내었으며, 도말 정경 음성-배양 양성군에서는 5예중 4예(80.0%), 그리고 도말 검경 음성-배양 음성군에서는 26예중 6예(23.1%)가 양성을 나타내었고 음성 대조군 검체 16예에서 2예(12.5%)에서 양성을 나타내였다. 결론 : 이상의 결과로, PCR은 객담에서의 결핵균의 진단에 있어, 배양과 견줄 수 있는 특이도와 예민도를 보이고 있어, 특정한 경우 진단에 도움을 줄 수 있을 것으로 기대되며, 추후 방법의 개선을 위한 연구가 계속 필요할 것으로 사료된다.

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Lymphoscintigraphy에 이용되는 방사성의약품의 사용제한으로 인한 대체 방사성의약품의 성능평가 (Performance Evaluation of Substitution Radiopharmaceutical according to Restriction of the Radiocolloids in Lymphoscintigraphy)

  • 서영덕;정재훈;문종운;윤상혁;김영석;강세훈;원우재;김석기
    • 핵의학기술
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    • 제13권1호
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    • pp.25-29
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    • 2009
  • Purpose: Several radioactive agents were used for lymphoscintigraphy in breast cancer. But recently, due to the change of local radiopharmaceutical licensing policy and discontinuation of supplies from manufacturer, we could not use many radiocolloids such as $^{99m}Tc$-Antimony Trisulfide Colloid, $^{99m}Tc$-Tin Colloid, $^{99m}Tc$-Human Serum Albumin. So it is necessary to use the substitution radiopharmaceutical. Therefore, this study aims to evaluate the performance of substitution radiopharmaceutical ($^{99m}Tc$-Phytate) including the existing radiocolloids and to set up of the appropriate protocol in lymphoscintigraphy. Materials and Methods: For each radiocolloids ($^{99m}Tc$-Antimony Trisulfide Colloid (ASC), $^{99m}Tc$-Tin Colloid (TC), $^{99m}Tc$-Human Serum Albumin (HSA), $^{99m}Tc$-Phytate) were performed the particle size by Zeta Sizer (Nano-ZS) and we compared the radiolabeling time, procedure and acquisition time for each of the radiocolloids (total 200 patients). For the last time, we made an analysis of image for each of the radiocolloids with our previous report (SJ Jang et al, Korean Nucl Med Mol imaging Vol.41, No.6, Dec 2007). Results: The particle size of each radiocolloids showed A.S.C (50 nm), T.C (310 nm), H.S.A (10.8 nm), $^{99m}Tc$-Phytate (499 nm). The labeling and acquisition time for each of the radiocolloids showed no substantial difference. But there is difference of the labeling time for the A.S.C. because the ASC procedure need to boiling process. There were no significant differences among those radiocolloids (p>0.005) in the identification rate (IR), false negative rate (FNR), and negative predictive value (NPV). Conclusions: $^{99m}Tc$-labeled radiocolloids showed equivalent results in lymphoscintigraphy. Therefore, in this exam of each radiocolloids could be applied appropriate protocol in lymphoscintigraphy.

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구강 편평세포암종의 경부 림프절전이에 대한 임상통계학적 연구 (A CLINICO-STATISTICAL STUDY ON CERVICAL LYMPH NODE METASTASIS OF ORAL SQUAMOUS CELL CARCINOMA)

  • 이재욱;김진욱;김진수
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제34권6호
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    • pp.594-601
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    • 2008
  • Cervical lymph node metastasis is one of the most important predicting factors that influence the prognosis of oral squamous cell carcinoma. Correct diagnosis on cervical lymph node metastasis is essential in determining the extent of operation and treatment modality. So we investigated a clinico-statistical evaluation on cervical lymph node metastasis in 183 patients who were diagnosed with oral squamous cell carcinoma at the Department of Oral and Maxillofacial Surgery in Kyungpook National University Hospital, from January 1st, 1999 to December 31st, 2007. The following results were obtained : 1. Among 183 patients who were diagnosed with oral squamous cell carcinoma, 149 were male and 49 were female. The average age of the patients was 61.8 years old. 2. Patients with advanced T classification showed higher incidence of cervical lymph node metastasis than those with lower T classification. 3. Patients with less differentiated tumors had higher tendency of manifesting cervical lymph node metastasis than those with more differentiated tumors. 4. Sensitivity and specificity on PET/CT was 87.5% and 58.3% respectively. PET/CT showed higher sensitivity and lower false-negative values than those of CT or USG. 5. The 5 - year survival rate of all the oral squamous cell carcinoma patients appeared to be 63.2% By N classification, patients in N0 stage showed a higher survival rate than patients in N1 or N2. 5 - year survival rates according to the modality of neck dissection were as follows in increasing order: no neck dissection group, MRND group, SND group, and RND group.

Detection Rate of Intravascular Injections during Cervical Medial Branch Blocks: A Comparison of Digital Subtraction Angiography and Static Images from Conventional Fluoroscopy

  • Jeon, Young Hoon;Kim, Sae Young
    • The Korean Journal of Pain
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    • 제28권2호
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    • pp.105-108
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    • 2015
  • Background: The most definitive diagnosis of neck pain caused by facet joints can be obtained through cervical medial branch blocks (CMBBs). However, intravascular injections need to be carefully monitored, as they can increase the risk of false-negative blocks when diagnosing cervical facet joint syndrome. In addition, intravascular injections can cause neurologic deficits such as spinal infarction or cerebral infarction. Digital subtraction angiography (DSA) is a radiological technique that can be used to clearly visualize the blood vessels from surrounding bones or dense soft tissues. The purpose of this study was to compare the rate of detection of intravascular injections during CMBBs using DSA and static images obtained through conventional fluoroscopy. Methods: Seventy-two patients were included, and a total of 178 CMBBs were performed. The respective incidences of intravascular injections during CMBBs using DSA and static images from conventional fluoroscopy were measured. Results: A total of 178 CMBBs were performed on 72 patients. All cases of intravascular injections evidenced by the static images were detected by the DSAs. The detection rate of intravascular injections was higher from DSA images than from static images (10.7% vs. 1.7%, P < 0.001). Conclusions: According to these findings, the use of DSA can improve the detection rate of intravascular injections during CMBBs. The use of DSA may therefore lead to an increase in the diagnostic and therapeutic value of CMBBs. In addition, it can decrease the incidence of potential side effects during CMBBs.

고관전압 흉부촬영의 가상결절을 이용한 ROC평가 (Evaluation of ROC Curve in High Kilovoltage Technique Using Simulated Nodules on Chest)

  • 안진신;장명미;정경모;정환;임정기;김종효
    • 대한방사선기술학회지:방사선기술과학
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    • 제15권2호
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    • pp.25-30
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    • 1992
  • With transmitted dose through chest which has the problem of wide variations in absorption, simple film/screen combination method makes it diffucult to image lung field, mediastinum and retrocardiac areas. In order to overcome this, it is very common to use the high kilovoltage technique in diminishing the differences between high and low contrast. We have been adopting this method at department of diagnostic radiology, Seoul National University Hospital. To compare the image of it with that of low kilovoltage technique, we did radiographic tests using beans on the skin. We marked off into three anatomical categories such as lungs, mediastinum and near diaphragm, then attached a bean on a marked area at random. In order to compare with high and low, we took a radiography of high($120{\sim}140\;kVp$) and low($70{\sim}90\;kVp$) kilovoltage tehchniques, respectively at the same time. We have done experiments 320 cases. We evaluated the results of test in response to sensitivity(true positive) and specificity(true negative). In evaluating, we gave them points from 1 to 5 according to true or false. With given points by a radiologist having much experiences, we could acquire the percentage of sensitivity and specificity. The percentage made us to get the schematic table of ROC curve of those two methods. Consequently, high kilovoltage technique appeared 18% better than low kilovoltage technique for detecting beans with our apparatus.

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내부 네트워크에서 알려지지 않은 피싱사이트 탐지방안 (A Unknown Phishing Site Detection Method in the Interior Network Environment)

  • 박정욱;조기환
    • 정보보호학회논문지
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    • 제25권2호
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    • pp.313-320
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    • 2015
  • 피싱 공격이 지속적이고 다양하게 증가하고 있지만 대응방안은 아직도 공격을 식별한 이후에 방어하는 형태에 머무르고 있다. 공격 이전에 HTTP의 Referer 헤더필드를 이용한 피싱사이트 탐지방안이 제안 되었으나, 피싱의 표적이 될 사이트 마다 개별적인 트래픽 수집 시스템을 설치해야하는 한계점이 존재한다. 본 논문은 내부 네트워크에서 기존에 알려져 있지 않은 피싱사이트에 접속하는 것을 탐지하는 방안을 제안한다. 사용자가 피싱사이트에 접속할 때 발생하는 트래픽을 HTTP 프로토콜의 특성과 피싱사이트 특성을 바탕으로 전처리를 수행한다. 피싱으로 의심되는 사이트는 컨텐츠를 분석하는 피싱사이트 판단단계를 통해 탐지된다. 제안된 탐지방안은 100개의 피싱 URL과 100개의 정상 URL을 대상으로 두 가지 형태의 실험으로 검증하였다. 실험결과 피싱 URL의 탐지율은 66%, 정상 URL에 대한 오탐율 0%로 나타났으며, 이는 기존에 제안된 탐지방안에 비해 알려지지 않은 피싱사이트를 탐지하는데 높은 탐지율을 보인다.

Anti-HBc 단독 양성자에서 B형 간염 백신 접종의 면역 반응과 B형 간염 DNA의 조사 (A Study of Immune Response to Hepatitis B Vaccine & HBV DNA in Isolated Anti-HBc Positive Subjects)

  • 김순덕;최지호;김성열;이진수;고희정
    • Journal of Preventive Medicine and Public Health
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    • 제38권2호
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    • pp.170-174
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    • 2005
  • Objectives: The aim of this study was to evaluate the response to a hepatitis B vaccination, and investigate the HBV DNA in subjects with isolated anti-HBc. Methods: 34 subjects with persistent isolated anti-HBc were included in the study. 32 subjects negative for HBsAg, anti-HBs and anti-HBc were included as a control group. They were all vaccinated with Hepaccine at 0, 1 and 2 months, and anti-HBs titers were measured 1 month after the 1st and 3rd vaccinations (1 and 3 months). The HBV-DNA was tested by polymerase chain reaction in subjects with isolated anti-HBc. Results: After the 1st & 3rd vaccinations, the anti-HBs titers$\geq$10mIU/ml were 70.6 & 70.6% in isolated anti-HBc group, and 34.4 & 81.2% in the control group, respectively. There were statistically significant differences after the 1st vaccination, but none after the 3rd, between the two groups. In the isolated anti-HBc and control groups, the primary, amnestic and no responses were 0 vs. 46.9%, 55.9 vs. 6.3% and 29.4 vs. 18.8%, respectively. The HBV DNA was not detected in all subjects with isolated anti-HBc. Conclusion: None of the subjects with isolated anti-HBc had a false positive result (primary response); therefore, they should be excluded from vaccination programs in Korea. To differentiate between immunity and occult infections, a single dose of vaccine, with a follow-up anti-HBs test, is preferable for subjects with isolated anti-HBc. An amnestic response indicates late immunity, and no response a suspect occult infection.

Knowledge, Behavior and Beliefs Related to Cervical Cancer and Screening Among Turkish Women

  • Reis, Nesrin;Bebis, Hatice;Kose, Sevinc;Sis, Asli;Engin, Raziye;Yavan, Tulay
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권4호
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    • pp.1463-1470
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    • 2012
  • Objective: The aims of this study were to explore Turkish women's knowledge, behavior and beliefs related to cervical cancer and screening. Methods: The study was performed in two cities in the East of Turkey between September 2009 and April 2010, with a sampling group of 387 women. Data were collected by means of an interview form with the Health Belief Model Scale for Cervical Cancer and Pap Smear Test - Turkish Version. Results: Women in the research group were found to have poor knowledge, inadequate health behavior and low/medium level false beliefs regarding cervical cancer screening. There was relation between health beliefs and characteristics of women and particularly education (F = 10.80, p = 0.01). Similarly, it was found that Pap smear barriers were influenced by demographic characteristics and that women with low-level education (p = 0.001), divorced women (p = 0.05), women with low-income(p = 0.05), women who gave their first birth when they were 18 or younger (p = 0.05) and women not applying any contraceptive method at all (p = 0.01) were determined to have negative Pap smear barriers. Conclusions: Primarily the knowledge, attitudes and beliefs of women in the target group should be evaluated to increase their participation in cervical cancer screening and to prepare effective education strategies.

색 항등성과 기하학적 분석 기반 얼굴 검출 기법 (Face Detection Method Based on Color Constancy and Geometrical Analysis)

  • 이우람;황동국;전병민
    • 대한전자공학회논문지SP
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    • 제48권4호
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    • pp.59-66
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    • 2011
  • 본 논문은 영상에서 장면 일루미넌트와 카메라의 위치에 따라 다양한 색과 형태로 나타나는 얼굴을 찾기 위해 색 항등성과 기하학적 분석 기반 검출 기법을 제안한다. 색 항등성 기법을 적용하여 영상에서 장면 일루미넌트의 영향을 제거하고, 기하학적 분석을 통해 다양한 형태로 나타나는 얼굴의 검출한다. 제안한 기법은 색 항등성 기법이 적용된 영상에서 얼굴과 헤어 후보영역을 추출하고, 다양한 기준을 이용하여 후보 영역을 분류한다. 그리고 각 얼굴 후보 영역을 대상으로 헤어 후보 영역과의 교차 영역을 계산하여 얼굴로 판단한다. Caltech Face DB내의 영상들을 이용하여 타 기법과의 성능을 비교하였고, 유색 조명 효과가 부가된 영상들을 대상으로 장면 일루미넌트에 대한 성능을 평가하였다. 실험 결과 제안한 기법은 다양한 입력 영상에서 얼굴 검출이 가능하였고 TP와 낮은 FN 수치로 나타났다.

외과적 갑상선 결절에 대한 임상적 고찰 (A Clinical Study on Surgical Thyroid Nodules)

  • 박현정;문상은
    • 대한두경부종양학회지
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    • 제9권2호
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    • pp.234-243
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    • 1993
  • The thyroid nodules are the most common endocrine disease requiring surgical management. Up to date, various diagnostic techniques and surgical management have been developed. Authors analysed 2285 cases of thyroid nodules who were treated at Department of Surgery, Pusan National University for the duration of 10 years from January 1980 to December 1989 and the results obtained were summerized as follows: 1) Patients were composed of 1727 cases(75.8%) of benign nodule and 558 cases(24.5%) of malignant nodule. Benign nodule was prevalent in forth and fifth decade comparing with malignant nodule was sixth and fifth decade. The sexual distribution revealed female preponderance with 1:10.8 in benign nodule and 1:9.3 in malignant nodule. 2) The histopathologic classfication of benign nodule in decreasing order of frequency were follicular adenoma 1009 cases(54.8%), adenomatous goiter 573 cases(33.3%), simple cyst 65 cases(3.8%), and Hashimoto's thyroiditis 52 cases(3.0%). The malignant disease were papillary adenocarcinoma 460 cases(82.4%), follicular adenocarcinoma 69 cases(12.4%), undifferentiated carcinoma 13 cases (2.0%), and medullary carcinoma 7 cases(1.0%). 3) Fine needle aspiration cytology was performed in 1758 cases and it showed 80.5% of sensitivity, 96.5% of specificity, 19.5% of false negative and 80% of accuracy. 4) The location of nodule was 87.7%, in unilateral, 12.2% in bilateral. 5) On the radioiodine scanning, the incidence of benign nodule with cold nodule was 83.9% and the incidence of benign nodule with hot nodule was 7.5%. The incidence of thyroid carcinoma with cold nodule was 88.3% and the incidence of thyroid carcinoma with hot nodule was 4.6%. 6) Most cases of benign nodules were treated with lobectomy 82.6%, subtotal thyroidectomy 10.1% and subtotal lobectomy 3.0%. Malignant nodules were treated with lobectomy and/or isthmusectomy 37.6%, total thyroidectomy 17.7%, subtotal thyroidectomy 15.4%, and any thyroidectomy and neck dissection 13.5%. 7) Postoperative complications were developed in 3.8% of benign nodules and 13.8% of malignant nodules.

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