• Title/Summary/Keyword: false negative

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Diagnostic testing for Duchenne/Becker Muscular dystrophy using Dual Priming Oligonucleotide (DPO) system (Dual Priming Oligonucleotide (DPO) system을 이용한 듀시엔/베커형 근이영양증 진단법)

  • Kim, Joo-Hyun;Kim, Gu-Hwan;Lee, Jin-Joo;Lee, Dae-Hoon;Kim, Jong-Kee;Yoo, Han-Wook
    • Journal of Genetic Medicine
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    • v.5 no.1
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    • pp.15-20
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    • 2008
  • Purpose : Large exon deletions in the DMD gene are found in about 60% of DMD/BMD patients. Multiplex PCR has been employed to detect the deletion mutation, which frequently generates noise PCR products due to the presence of multiple primers in a single reaction as well as the stringency of PCR conditions. This often leads to a false-negative or false-positive result. To address this problematic issue, we introduced the dual primer oligonucleotide (DPO) system. DPO contains two separate priming regions joined by a polydeoxyinosine linker that results in high PCR specificity even under suboptimal PCR conditions. Methods : We tested 50 healthy male controls, 50 patients with deletion mutation as deletion-positive patient controls, and 20 patients with no deletions as deletion-negative patient controls using DPO-multiplex PCR. Both the presence and extent of deletion were verified by simplex PCR spanning the promoter region (PM) and 18 exons including exons 3, 4, 6, 8, 12, 13, 17, 19, 43-48, 50-52, and 60 in all 120 controls. Results : DPO-multiplex PCR showed 100% sensitivity and specificity for the detection a deletion. However, it showed 97.1% sensitivity and 100% specificity for determining the extent of deletions. Conclusion : The DPO-multiplex PCR method is a useful molecular test to detect large deletions of DMD for the diagnosis of patients with DMD/BMD because it is easy to perform, fast, and cost-effective and has excellent sensitivity and specificity.

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Diagnostic and Therapeutic Utility of Ultrasonography-guided Facet Joint Block in Chronic Cervical Spinal Pain (만성 경추 동통 환자에서 초음파를 이용한 후관절 차단술의 진단 및 치료적 유용성)

  • Kim, Tae Kyun;Shim, Dae Moo;Oh, Sung Kyun;Choi, Byong San;Han, Sang Su
    • The Journal of Korean Orthopaedic Ultrasound Society
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    • v.3 no.2
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    • pp.54-58
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    • 2010
  • Purpose: In patients with chronic cervical pain, the facet joint is the source of the majority. Due to the difficulty of identifying the exact location of the joint that causes these symptoms, the possibility of complications and the placebo effect brings clinical application into question. In this study, we assessed the prevalence of patients with chronic cervical pain and report the diagnostic and therapeutic usefulness of ultrasonography - guided facet joint block therapy. Materials and Methods: Patients with nonspecific chronic cervical pain for more than 6 months were selected. Patients with disc herniation, sciatica-related pain were excluded from the study and 160 patients who failed in conservative treatment (physical therapy, chiropractic therapy, medication) were included in the study. Diagnostic Ultrasonography-guided facet joint block was performed with 1% lidocaine, and after two weeks, Bupivacaine 0.25% was used in patients who tested positive for lidocaine. Patients with more than 75% pain reduction during movement after facet joint block were considered positive. Results: Among the 160 patients with chronic cervical pain, 96 patients(60%) had a positive reaction after facet block using lidocaine. Among the 64 patients with a negative reaction to lidocaine, 48 patients(75%) had a positive reaction to bupivacaine. There were 48 false positive patients(50%) who showed a positive reaction to lidocaine but a negative reaction to bupivacaine. The mean VAS of the total 160 patients before blocks was 8.5, after 2 weeks follow up it decreased to 2.7 (p = 0.001) and after 4weeks 3.6 (p = 0.001). The 8 patients as an initial improvement of symptoms are not satisfied with the procedure and the 3 patients had been worsened during observation, were showed pain relief after additional ultrasonography-guided facet joint block at 4th week. Conclusion: A single ultrasonography-guided block to chronic cervical pain patients has relatively low diagnostic value since high false positive rate. The twice facet joint blocks is thought to be a useful method for interventional pain management of patients with chronic cervical pain.

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Combination of FDG PET/CT and Contrast-Enhanced MSCT in Detecting Lymph Node Metastasis of Esophageal Cancer

  • Tan, Ru;Yao, Shu-Zhan;Huang, Zhao-Qin;Li, Jun;Li, Xin;Tan, Hai-Hua;Liu, Qing-Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7719-7724
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    • 2014
  • Background: Lymph node metastasis is believed to be a dependent negative prognostic factor of esophageal cancer. To explore detection methods with high sensitivity and accuracy for metastases to regional and distant lymph nodes in the clinic is of great significance. This study focused on clinical application of FDG PET/CT and contrast-enhanced multiple-slice helical computed tomography (MSCT) in lymph node staging of esophageal cancer. Materials and Methods: One hundred and fifteen cases were examined with enhanced 64-slice-MSCT scan, and FDG PET/CT imaging was conducted for neck, chest and upper abdomen within one week. The primary lesion, location and numbers of metastatic lymph nodes were observed. Surgery was performed within one week after FDG PET/CT detection. All resected lesions were confirmed histopathologically as the gold standard. Comparative analysis of the sensitivity, specificity, and accuracy based on FDG PET/CT and MSCT was conducted. Results: There were 946 lymph node groups resected during surgery from 115 patients, and 221 were confirmed to have metastasis pathologically. The sensitivity, specificity, accuracy of FDG PET/CT in detecting lymph node metastasis were 74.7%, 97.2% and 92.0%, while with MSCT they were 64.7%, 96.4%, and 89.0%, respectively. A significance difference was observed in sensitivity (p=0.030), but not the others (p>0.05). The accuracy of FDG PET/CT in detecting regional lymph node with or without metastasis were 91.9%, as compared to 89.4% for MSCT, while FDG PET/CT and MSCT values for detecting distant lymph node with or without metastasis were 94.4% and 94.7%. No significant difference was observed for either regional or distant lymph node metastasis. Additionally, for detecting para-esophageal lymph nodes metastasis, the sensitivity of FDG PET/CT was 72%, compared with 54.7% for MSCT (p=0.029). Conclusions: FDG PET/CT is more sensitive than MSCT in detecting lymph node metastasis, especially for para-esophageal lymph nodes in esophageal cancer cases, although no significant difference was observed between FDG PET/CT and MSCT in detecting both regional and distant lymph node metastasis. However, enhanced MSCT was found to be of great value in distinguishing false negative metastatic lymph nodes from FDG PET/CT. The combination of FDG PET/CT with MSCT should improve the accuracy in lymph node metastasis staging of esophageal cancer.

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

  • Seo, Young-Deok;Jeong, Jae-Hun;Moon, Jong-Woon;Yun, Sang-Hyeok;Kim, Yeong-Seok;Kang, Se-Hun;Won, Woo-Jae;Kim, Seok-Ki
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.1
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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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The Safety and Efficacy of Mediastinoscopy in Non-small Cell Lung Cancer (비소세포폐암에서 종격동경검사의 안전성과 유용성)

  • Park In-Kyu;Cho Sang-Ho;Kim Dae-Joon;Chung Kyung-Young
    • Journal of Chest Surgery
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    • v.39 no.6 s.263
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    • pp.470-474
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    • 2006
  • Background: Mediastinal lymph node metastasis is an important factor for staging and prognosis of non-small cell lung cancer (NSCLC), so accurate diagnosis is essential for treatment. Mediastinoscopy provides histopathological diagnosis of mediastinal lymphnode metastasis in NSCLC. The efficacy of mediastinoscopy was investigated. Material and Method: From Jun, 1999 to Aug, 2005, mediastinoscopic lymph node biopsy was performed to 348 patients with NSCLC. Patients characteristics, radiologic findings, mediastinoscopic results and pathologic stages were evaluated for investigation of safety and efficacy of modiastinoscopy in NSCLC. Result: There was 263 male and 85 female patients and the mean age was $62.1{\pm}8.5$ years. By radiologic study for mediastinal lymph node metastasis, 203 patients were negative and 145 patients were positive. Mean procedure time was $55.5{\pm}16.5$ minutes and biopsy was peformed at $2.2{\pm}1.0$ lymph node stations. There were only transient complications (1.7%) during the procedure, without other complication and mortality. There was 7.8% of false negative result in mediastinoscopy. Sensitivity (77.5% vs 71.9%, p=0.012), specificity (100% vs 74.4%, p=0.00), and accuracy (92.2% vs 73.6%, p=0.00) of mediastinoscopy were more superior than that of radiologic study for the diagnosis of mediastinal lymph node metastasis in NSCLC. Conclusion: Mediastinoscopy is a safe and effective modality for diagnosis of mediastinal lymph node metastasis in NSCLC.

Comparison of the Real-Time Nucleic Acid Sequence-Based Amplification (NASBA) Assay, Reverse Transcription-PCR (RT-PCR) and Virus Isolation for the Detection of Enterovirus RNA. (엔테로바이러스 검출을 위한 real-time nucleic acid sequence-based amplification (NASBA), reverse transcription-PCR (RT-PCR) 및 바이러스 배양법의 비교)

  • Na, Young-Ran;Joe, Hyeon-Cheol;Lee, Young-Suk;Bin, Jae-Hun;Cheigh, Hong-Sik;Min, Sang-Kee
    • Journal of Life Science
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    • v.18 no.3
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    • pp.374-380
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    • 2008
  • Rapid detection of enterovirus (EVs) is important in the management of aseptic meningitis. We examined the relative efficiency and specificity of the real-time nucleic acid sequence-based amplification (NASBA) comparing with the established reverse transcription polymerase chain reaction (RT-PCR) and viral culture method which were used for the detection of enterovirus RNA in clinical specimens. Of the total 292 samples, 145 were found to be positive to enterovirus RNA by real-time NASBA, 101 were positive by viral culture, and 86 were positive by RT-PCR. 147 samples and 46 samples were determined to be negative and positive by all methods respectively, but 4 samples were positive only by real-time NASBA. To compare the specificity of each method, various clinical samples which were diagnosed for herpes simplex virus (HSV)-1, HSV-2, adenovirus, mumps, and rhinovirus were applied. Except one rhinovirus sample which was false positive to enterovirus RNA by RT-PCR, the other different samples were negative to all three methods. The real-time NASBA procedure can be completed within 5 hours in contrast with 9 hours for the RT-PCR and 3-14 days for the viral culture. From this study, it was suggested that the real-time NASBA assay could be a standardized, rapid, specific, and sensitive procedure for the detection of enterovirus RNA.

Research on factors influencing consumer trust in livestreaming e-commerce (라이브 스트리밍 전자 상거래에서 소비자 신뢰에 영향을 미치는 요인에 관한 연구)

  • Xiao yong Lyu;Jae-Yeon Sim
    • Industry Promotion Research
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    • v.8 no.3
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    • pp.181-199
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    • 2023
  • E-commerce is gradually upgrading from traditional text and image formats to short video and livestreaming formats. Livestreaming e-commerce enriches the content and forms of information dissemination and product display, enhances the consumer's shopping experience, and gradually becomes the mainstream new consumer scene. However, there are many negative phenomena in the development of livestreaming e-commerce, such as false propaganda, counterfeit goods, and various negative events, which seriously affect the level of consumer trust in livestreaming e-commerce. Trust is the core competitive factor of livestreaming e-commerce. Based on previous research on trust theory and combined with the characteristic elements of "people, goods, and scenes" of livestreaming e-commerce, this article constructs a trust model for livestreaming e-commerce, proposes hypotheses, and proves through empirical research that factors such as store characteristics, livestream host characteristics, brand image, product information, platform reputation, livestreaming situation, and trust tendency have a significant positive impact on consumer trust. Based on the research conclusions, this article provides insights and management suggestions, such as emphasizing the construction of store characteristic indicators, creating desirable livestream host characteristics, focusing on product brand building and selection, maintaining the display of product information, selecting suitable livestreaming platforms, and creating rich content for livestreaming situations.

Appendiceal Visualization on 2-mSv CT vs. Conventional-Dose CT in Adolescents and Young Adults with Suspected Appendicitis: An Analysis of Large Pragmatic Randomized Trial Data

  • Jungheum Cho;Youngjune Kim;Seungjae Lee;Hooney Daniel Min;Yousun Ko;Choong Guen Chee;Hae Young Kim;Ji Hoon Park;Kyoung Ho Lee;LOCAT Group
    • Korean Journal of Radiology
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    • v.23 no.4
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    • pp.413-425
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    • 2022
  • Objective: We compared appendiceal visualization on 2-mSv CT vs. conventional-dose CT (median 7 mSv) in adolescents and young adults and analyzed the undesirable clinical and diagnostic outcomes that followed appendiceal nonvisualization. Materials and Methods: A total of 3074 patients aged 15-44 years (mean ± standard deviation, 28 ± 9 years; 1672 female) from 20 hospitals were randomized to the 2-mSv CT or conventional-dose CT group (1535 vs. 1539) from December 2013 through August 2016. A total of 161 radiologists from 20 institutions prospectively rated appendiceal visualization (grade 0, not identified; grade 1, unsure or partly visualized; and grade 2, clearly and entirely visualized) and the presence of appendicitis in these patients. The final diagnosis was based on CT imaging and surgical, pathologic, and clinical findings. We analyzed undesirable clinical or diagnostic outcomes, such as negative appendectomy, perforated appendicitis, more extensive than simple appendectomy, delay in patient management, or incorrect CT diagnosis, which followed appendiceal nonvisualization (defined as grade 0 or 1) and compared the outcomes between the two groups. Results: In the 2-mSv CT and conventional-dose CT groups, appendiceal visualization was rated as grade 0 in 41 (2.7%) and 18 (1.2%) patients, respectively; grade 1 in 181 (11.8%) and 81 (5.3%) patients, respectively; and grade 2 in 1304 (85.0%) and 1421 (92.3%) patients, respectively (p < 0.001). Overall, undesirable outcomes were rare in both groups. Compared to the conventional-dose CT group, the 2-mSv CT group had slightly higher rates of perforated appendicitis (1.1% [17] vs. 0.5% [7], p = 0.06) and false-negative diagnoses (0.4% [6] vs. 0.0% [0], p = 0.01) following appendiceal nonvisualization. Otherwise, these two groups were comparable. Conclusion: The use of 2-mSv CT instead of conventional-dose CT impairs appendiceal visualization in more patients. However, appendiceal nonvisualization on 2-mSv CT rarely leads to undesirable clinical or diagnostic outcomes.

Evaluation of a Serodiagnostic Method for Tuberculosis by Using Secreted Protein Antigens of Mycobacterium Tuberculosis (결핵균 분비항원을 이용한 결핵의 혈청학적 진단 방법에 대한 평가)

  • Bai, Gill-Han;Park, Eun-Mi;Kim, Sang-Jae
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.3
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    • pp.315-323
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    • 2000
  • Background : An immunochromatographic assay (ICT Diagnostics) which facilitates the diagnosis of tuberculosis(TB) by detecting serum antibodies mainly directed against specific 38KDa of Mycobacterium tuberculosis has come into the market. The test consists of a cardboard folding device containing nitrocellulose strip and absorbent pads. The whole procedure is completed within 15 min and does not require any additional equipment. The test has been reported to be sensitive and specific in diagnosing active TB. Thus the test had been evaluated with sera from TB patients and TB-free subjects. Method : Sera from patients with active pulmonary tuberculosis(40 sputum positives for Mycobacterium tuberculosis, 79 sputum negatives, and 3 extrapulmonary tuberculosis) were obtained from the Double-Cross Chest Clinic of the Korean National Tuberculosis Association (KNTA) in Seoul. The control group consisted of TB-free 68 subjects(21 children under 7 years old and 47 healthy staff members of KNTA). Results : Nine out of 68(13.2%) TB-free controls had positive antibody response. Total 106 of 122(86.9%) radiologically active patients had positive antibodies while 16 (13.1%) showed negative reaction. Antibody was detected in 38 of 40(95.0%) sputum positive patients and 68 of 82(82.9%) sputum negative patients who were under the antituberculosis chemotherapy. The sensitivity and specificity were all 87% and the positive predictive value was 92.2% while the negative predictive value was 78.7%, when the prevalence of TB in the sample was 64.2%. Our results clearly show that the detection of antibodies which mainly react with the 38KDa antigen of M. tuberculosis is not suitable as the first-line method of diagnosis but considered only as an adjunctive test to standard techniques of tuberculosis diagnosis. when considering its high false positivity.

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Usefulness of $^{18}F-FDG$ PET/CT in the Diagnosis of Cervical Lymph Node Metastases of Head and Neck Cancer (두경부암 경부 림프절 전이의 진단에서 $^{18}F-FDG-PET/CT$의 유용성)

  • Kim, Chung-Ho;Kim, Sung-Hoon;O, Joo-Hyun;Yoo, Ie-Ryung;Chung, Yong-An;Park, Young-Ha;Sohn, Hyung-Sun;Lee, Sung-Young;Chung, Soo-Kyo
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.5
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    • pp.269-277
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    • 2005
  • Purpose: This study evaluated the diagnostic value of $^{18}F-FDG$ PET/CT in detecting cervical lymph node metastases in head and neck cancer patients. Materials & Methods: The patients were divided into two groups, 46 patients underwent PET/CT scan for initial staging before surgery, and 20 patients for restaging of recurrence after primary treatment. Increased FDG uptakes in cervical lymph nodes were evaluated retrospectively and correlated with the histopathologic results. Results: In the initial staging group, 21 lymph nodes were detected by PET/CT in 15 patients. 20 lymph nodes were confirmed as metastases with a mean peak SUV of 5.84, and the remaining one lymph node was an inflammatory lesion, with a peak SUV of 2.75. Seven metastatic lymph nodes were reported only by histopatholoay. The sensitivity, specificity, positive predictive value and negative predictive value were 74.0%, 99.6%, 95.2% and 97.3%, respectively. In the recurrence group, 11 lymph nodes were detected in 9 patients, and 8 nodes were true positive, with a mean peak SUV of 5.65. The other three were inflammatous lymph nodes, and the peak SUVs were 2.16, 2.94 and 3.53. One false negative lymph node was reported. The sensitivity, specificity, positive predictive value and negative predictive value were 88.8%, 97.7%, 72.7% and 92.9%, respectively. Conclusions: FDG-PET/CT shows higher positive predictive value in the initial staging group, and better sensitivity in the recurrence group. Therefore PET/CT could be useful for both initial staging and restaging of recurrent cervical lymph node metastases.