• Title/Summary/Keyword: False Negative

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Performance Improvement of Automatic Basal Cell Carcinoma Detection Using Half Hanning Window (Half Hanning 윈도우 전처리를 통한 기저 세포암 자동 검출 성능 개선)

  • Park, Aa-Ron;Baek, Seong-Joong;Min, So-Hee;You, Hong-Yoen;Kim, Jin-Young;Hong, Sung-Hoon
    • The Journal of the Korea Contents Association
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    • v.6 no.12
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    • pp.105-112
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    • 2006
  • In this study, we propose a simple preprocessing method for classification of basal cell carcinoma (BCC), which is one of the most common skin cancer. The preprocessing step consists of data clipping with a half Hanning window and dimension reduction with principal components analysis (PCA). The application of the half Hanning window deemphasizes the peak near $1650cm^{-1}$ and improves classification performance by lowering the false negative ratio. Classification results with various classifiers are presented to show the effectiveness of the proposed method. The classifiers include maximum a posteriori probability (MAP), k-nearest neighbor (KNN), probabilistic neural network (PNN), multilayer perceptron(MLP), support vector machine (SVM) and minimum squared error (MSE) classification. Classification results with KNN involving 216 spectra preprocessed with the proposed method gave 97.3% sensitivity, which is very promising results for automatic BCC detection.

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Detection of Hepatitis C Virus by RIA, Recombinant Immunoblot Assay and Nested RT-PCR (RIA, Recombinant Immunoblot Assay 및 Nested RT-PCR에 의한 C형 간염바이러스 검출)

  • Kim, Jae-Soo;Kim, Jong-Wan;Lee, Yun-Tai
    • The Journal of Korean Society of Virology
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    • v.30 no.2
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    • pp.151-159
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    • 2000
  • Hepatitis C virus (HCV) is one of the important human pathogen that can cause acute and chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Recently, the third generation radiation immuno assay (RIA) method has been developed as a very sensitive test to detect anti-HCV antibody. However, false positive is the problem with RIA test. To solve this the RIA results were compared to those of 5-antigen recombinant immunoblot assay (5-RIBA) and reverse transcription-polymerase chain reaction (RT-PCR). Among 12,767 serum samples tested from clinic visitors, total 275 (2.2%) samples were antibody positive by RIA. RIBA was performed with 148 RIA positives cases but among them was shown eighty five was antibody positive and sixty three (42.6%) was negative result. However, nested RT-PCR test was shown also carried out with 43 positive, 6 intermediates and 25 negatives of RIBA. As a result of the nested RT-PCR results, HCV antigen were detected in RIBA positive, 33.3% (2/6) RIBA intermediate and 12% (3/25). Clinical syndrome of all 148 patients as a with chronic active hepatitis (46.0%), cirrhosis (18.9%), hepatocellular carcinoma (8.1%) and others (27.0%) and they were positive in reaction by RIA test. But RIBA positive patients with 34.9% of chronic active hepatitis, 18.6% of cirrhosis, 4.6% of hepatocellular carcinoma and 41.9% of others were detected to be positive case by nested RT-PCR.

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Application of monoclonal antibody to develop diagnostic techniques for infectious bovine rhinotracheitis virus. II. Diagnosis of infectious bovine rhinotracheitis by using monoclonal antibody (소 전염성비기관염(傳染性鼻氣管炎) 바이러스에 대한 monoclonal antibody 생산(生産)과 진단법(診斷法) 개발 II. Monoclonal antibody를 이용한 소 전염성비기관염(傳染性鼻氣管炎)의 진단(診斷))

  • Jun, Moo-hyung;Kim, Duck-hwan;An, Soo-hwan;Lee, Jung-bok;Min, Won-gi
    • Korean Journal of Veterinary Research
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    • v.29 no.1
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    • pp.27-35
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    • 1989
  • To develop more specific and sensitive diagnostic methods for infectious bovine rhinotracheitis, 7-C-2 monoclonal antibody specific to polypeptides of infectious bovine rhinotracheitis virus (IBRV) was applied in indirect immunofluorescence antibody assay (IFA), indirect immunoperoxidase assay(IPA) and radial immunodiffusion enzyme assay (RIDEA). It was found that IBRV infected in MDBK cells could be detected as early as 8 hours post infection by IFA, and that IFA was more rapid and specific to identify IBRV antigen than IPA. The diagnostic efficacy of RIDEA and SN test was studied with 88 bovine sera. It was evident that RIDEA could eliminate the false positive reaction encountered in serum neutralization(SN) test, being more rapid and sensitive than the latter. Highly significant correlation coefficiency (r=0.76, p<0.01) was evaluated between the titers of sera and the diameters of RIDEA. Tracheal membranes and sera collected from 96 slaughtered cattle with lesions in respiratory organs were examined to detect IBRV antigen and antibody by IFA, RIDEA and SN test. It was presented that positive rates were 32.3% in IFA, 20.8% in RIDEA and 21.9% in SN test, and that coincidence rate between RIDEA and SN test were 100% in positive sera and 98.7% in negative sera. In conclusion, it was assumed that application of monoclonal antibody could improve the diagnostic efficacy of IBR by enhancing sensitivity and specificity of IPA, IFA and RIDEA.

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A comparative study of the gamma-interferon assay and the single intradermal tuberculin test for the diagnosis of bovine tuberculosis under field conditions (소 결핵병 검사에 사용되는 감마인터페론법과 단일피내접종법의 상관관계 비교분석)

  • Ha, Min-Jong;Oh, Gyeong-Min;Kim, Sang-Yun;Do, Jae-Cheul;Lee, Young-Ju
    • Korean Journal of Veterinary Service
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    • v.41 no.2
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    • pp.71-78
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    • 2018
  • Bovine tuberculosis (bTB) is a wide-spread zoonotic disease in cattle, which is casued by Mycobacterium bovis that is a part of Mycobacterium tuberculosis complex (MTC). This study describes a field trial conducted in 42 herds with the history of prevalence bovine tuberculosis. Two cell-mediated immunity tests, the gamma-interferon (${\gamma}-IFN$) assay and the single intradermal tuberculin test (SIT) were applied for the diagnosis of bovine tuberculosis in 5,289 animals. The ${\gamma}-IFN$ assay presented 144 (2.7%) head of cattle with the positive result, and 112 (2.1%) head of cattle were shown to be bTB-positive by the SIT. The positive concordance was 45.5%, and the negative concordance was 98.2%. The ${\gamma}-IFN$ assay showed more positive results in younger cattle, especially between 12 and 23 months of age. It is shown that the strategic combination of both cell-mediated immunity test methods is more efficient for the detection of bTB to reduce the number of false positive individuals which are being slaughtered.

Evaluation of Therapeutic Effect with Serum Thyroglobulin and Whole Body Scan after 200mCi $^{131}I$ Treatment in Patients with Well-Differentiated Thyroid Carcinoma (전이성 분화 갑상선암에서 200mCi 방사성 옥소 치료효과 평가를 위한 혈청 Thyroglobulin 추적검사와 전신스캔의 의의)

  • Lee, Chang-Hee;Yoon, Jong-Kil;Jeong, Sang-Hoon;Kwu, Gyo-Seon;Choi, Chang-Woon;Lim, Sang-Moo;Hong, Sung-Woon
    • The Korean Journal of Nuclear Medicine
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    • v.29 no.4
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    • pp.451-459
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    • 1995
  • Thirty-eight patients with metastatic well-differentiated thyroid carcinoma treated with 200mCi $^{131}I$ were studied. There were false negative serum thyroglobulin values during TSH suppression or at anti-thyroglobulin antibody(+) and discrepancies between findings of whole body scan and serum thyroglobulin level. After one to five cycles of 200mCi $^{131}I$ therapy, complete remission and partial remission were achieved at 5.3% and 57.9%, respectively. We concluded that all of serum thyroglobulin, TSH, anti-thyroglobulin antibody, $^{131}I$ or $^{123}I$ whole body scan were necessary in follow up of metastatic well-differentiated thyroid carcinoma. Also, if there was no response after repetitive 200mCi $^{131}I$ therapy, higher doses of $^{131}I$ therapy should be considered.

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Invasine Ductal Carcinoma with Osteoclast-Like Giant Cell in a Young Woman (유방의 침윤성 파골양 거대세포 관암종의 세포소견 - 1예 보고 -)

  • Kang, Hyun-Jeong;Choi, Kyung-Un;Kwak, Hee-Suk;Sol, Mee-Young;Kim, Jee-Yeon
    • The Korean Journal of Cytopathology
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    • v.18 no.1
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    • pp.69-73
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    • 2007
  • Mammary carcinoma with osteoclast-like giant cells is an unusual neoplasm characterized by giant cells, mononuclear stromal cells, and hemorrhage accompanying a low grade carcinoma. We present the cytological findings in a case of invasive ductal carcinoma with osteoclast-like giant cells that was initially confused with a fibroadenoma, due to its well-demarcated and soft mass and the young age of the patient. A 28-year-old female presented with a 4.5 cm, well demarcated, soft and nontender mass in the right breast. Fine needle aspiration cytology (FNAC) showed a combination of low grade malignant epithelial cell clusters and osteoclast-like giant cells. The atypical epithelial cells were present in cohesive sheets and clusters. Osteoclast-like giant cells and bland-looking mononuclear cells were scattered. An histological examination revealed the presence of an invasive ductal carcinoma with osteoclast-like giant cells. We report here the cytological findings of this rare carcinoma in a very young woman. The minimal atypia of the epithelial cells and its soft consistency may lead to a false negative diagnosis in a young woman. The recognition that osteoclastlike giant cells are rarely present in a low grade carcinoma, but not in benign lesion, can assist the physician in making a correct diagnosis.

The Efficiency of Cell Block in the Diagnosis of Non-gynecologic Cytology (비 산부인과 세포 검사 진단에 있어서세포 군집절편(Cell-Block)법의 유용성)

  • Han, Seung Hee;Youn, Mi Ja;Park, Byung Kyu;Lim, Byung Soo;Ahn, Mi Jung;Yang, Chul Kyu;Jeon, Geum Hee;Sung, Ha Ok
    • Korean Journal of Clinical Laboratory Science
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    • v.36 no.1
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    • pp.38-42
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    • 2004
  • Because of the lack of resources on the importance of cell block, the diagnosis of cytologic specimen has been overlooked. Out of 1,243 cases of non-gynecologic cytology specimen, about 87.1% has been proven to be diagnostically useful. About 0.9% of those were rendered diagnostic by cell block alone. If cell block was not made it could have resulted in misdiagnosis. The effect on making cell block might not be directly linked to the patient but to the pathologist, it can be a helpful secondary tool in lowering the chance of giving false negative results hence. Giving the patient the opportunity of an adequate treatment. This study has proven that cell block has diagnostic value in non-gynecologic cytology. We are doing our best to increase the production rate of cell block and to improve the quality of cytology smears and cell block, so that we can increase the accuracy of diagnosis.

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Discriminatory ability of cervical vertebral maturation stages in predicting attainment of the legal age threshold of 14 years: A pilot study using lateral cephalograms

  • Banda, Thirupathi Reddy;Komuravelli, Anil Kumar;Balla, Sudheer B.;Korrai, Bala Raju;Alluri, Kavya;Kondapaneni, Jayasurya;Abhyankar, Sourab
    • Imaging Science in Dentistry
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    • v.50 no.3
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    • pp.209-216
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    • 2020
  • Purpose: In India, the age of 14 years is the legal age threshold for child labour. Therefore, in suspected instances of child labour, age assessment plays a crucial role in determining whether a violation of the law on the employment of children has occurred. The aim of this retrospective cross-sectional study was to assess the discriminatory ability of stages of cervical vertebral maturation (CVM) in predicting the legal age threshold of 14 years. Materials and Methods: Routinely taken lateral cephalograms from 408 subjects aged 10 to 18 years were evaluated retrospectively using the CVM stages described by Baccetti et al. Descriptive statistics, accuracy, sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated for stages 2, 3, and 4 of CVM. Results: Real age increased as the CVM stage gradually increased. The results of 2×2 contingency tables showed that CVM stage 4 produced an accuracy of 71% and 73%, a false positive rate of 7% and 18%, and a post-test probability of 59% and 68% for boys and girls, respectively. Conclusion: Based on these findings, it can be concluded that the stages of CVM are of limited use for predicting the attainment of the legal age threshold of 14 years. Future studies should investigate whether combinations of skeletal and dental methods could achieve better accuracy and post-test probability.

A Perception of Dietitians for Using Imported Foods and Pro-environment Farm Products for Elementary School Foodservice Operations in Busan (수입 식재료 및 친환경 농산물 사용에 대한 부산지역 초등학교 영양사의 인식 조사)

  • Ryu, Mi-Jin;Seo, Jae-Su;Ryu, Eun-Sun
    • Journal of the Korean Dietetic Association
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    • v.10 no.4
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    • pp.452-466
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    • 2004
  • The purpose of this study was to assess the use of food materials at elementary school in Busan area and provide school meal management with basic data to improvement of guideline. A survey was done by e-mail with a set of questionnaires, which was responeded by 122 dietitians in elementary school foodservice. The results were as follows; Sixty percent of the dietitians though to the general imported food materials had to use. Regarding mean score of using the imported food materials; safety was 2.12/5.00, freshness 2.48/5.00, sanitation 2.68/5.00, nutrition 2.73/5.00, preference 2.93/5.00, external form 3.09/5.00, package 3.12/5.00, and price 3.63/5.00. Thirty seven percent of the dietitians had purchase the pro-environment farm products(PEFPs) and 32.0% of them purchased those products for the students' health. But 52.4% could not purchase to the PEFPs because of expensive price. They had negative opinions about deficient supplying of PEFPs 4.51/5.00, too expensive price 4.34/5.00, and the truth or false in source of PEFPs 3.96/5.00. Most of them perceived that using the PEFPs had to apply the step by step. Among of them, 33.9% had the knowledge of PEFPs, but 16.4 of them did not know to the PEPPs. 57.4% of them hoped to purchase the food materials through a center of supporting school meal servcie(it called non-profit-making organizations).

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FDG-PET/CT Complements Bone Scan with Respect to the Detection of Skip Metastasis of Osteosarcoma: A Case Report (골육종의 도약전이 진단에서 골스캔의 보완검사로서의 FDG-PET/CT: 증례 보고)

  • Cheon, Gi-Jeong;Choe, Jae-Gol;Chae, In-Jung;Lee, Dae-Hee;Song, Sang-Heon;Kim, Myo-Jong;Park, Jong-Hoon
    • The Journal of the Korean bone and joint tumor society
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    • v.18 no.1
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    • pp.45-49
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    • 2012
  • Skip lesion is not uncommon feature in osteosarcoma and considered to be importantly associated with poor prognosis factor, and thus, should be excised with the main mass. The accurate pre-operative evaluation of the intramedullary extent of osteosarcoma is essential, because it determines the level of bone resection. Among the reliable detection methods, bone scan has a drawback of high rate of false negative results and regional MRI has a difficulty to cover the whole involved lesions without clinical suspicion. The authors report a case of osteosarcoma of the distal femur with a proximal skip lesion that was not detected by either regional MR imaging or by bone scan, but which was visualized by FDG-PET/CT.