• Title/Summary/Keyword: False-negative reactions

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False positive and false negative reactions of acidic hydrogen peroxide for enhancing blood (Acidic hydrogen peroxide로 혈액을 증강할 때의 위양성 및 위음성 반응)

  • Lee, Wonyoung;Hong, Sungwook
    • Analytical Science and Technology
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    • v.35 no.3
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    • pp.124-128
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    • 2022
  • Blood-sensitive reagents may exhibit false positives or negatives under the influence of substances other than blood. Since these reactions lead to the misinterpretation of blood evidence, it is essential to investigate the possibility of false-positive and -negative reactions of blood-sensitive reagents. Acidic hydrogen peroxide (AHP) is a recently discovered blood-sensitive reagent, and it is not yet known whether it causes false-positive or -negative reactions. To confirm this, 20 µL of blood was placed on metal surfaces, plastic surfaces, paper surfaces, paint surfaces, foods, vegetable oils, detergents, and petroleum hydrocarbons, and then AHP was applied. The blood was observed through an orange filter under a 505-nm light source, and no false-positive or false-negative reactions were observed with any of the substances/materials. However, it was confirmed that polyethylene terephthalate surfaces, polyvinylchloride surfaces, some paint surfaces, and foods exhibit their own photoluminescence under the conditions of blood observation, which interferes with blood observation.

The Relationship between Chinese Parents' Reaction to Children's Negative Emotions and Children's Understanding of Emotions

  • Jin, Rihua;Lee, Young
    • Child Studies in Asia-Pacific Contexts
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    • v.4 no.2
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    • pp.109-126
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    • 2014
  • The purpose of this study was to investigate Chinese parents' reaction to their children's negative emotions and how these reactions relate to their children's understanding of emotions. Forty-two Chinese children (aged 4) and their parents participated in this study. Coping with Children's Negative Emotion Scale was given to parents to assess their reaction to their children's negative emotions. Children's emotional understanding was assessed using the modified emotional false-belief task and mixed emotion task. The results showed that Chinese parents gave supportive reactions more than non-supportive reactions to their children, and no difference in sex was found. The percentages of correct answers to false-belief task and mixed emotion task were low with no gender difference in both tasks. When age and sex of children were controlled, only fathers' supportive reactions to children's negative emotions significantly explained the variances in the level of children's understanding of emotions in both tasks. That is, children whose fathers showed greater supportive reactions to their negative emotions performed better at both tasks. It was concluded that fathers' supportive reactions to their children's negative emotions are very influential for emotional understanding among 4-year-old children in China.

Comparison of Enzyme-linked Immunosorbent Assay with Reverse Transcription-polymerase Chain Reaction for Identification of Rotavirus in Neonates (신생아 로타바이러스 감염 진단에서 효소면역법과 중합효소연쇄반응과의 비교)

  • Kim, Sung Eun;Kim, Mi Ok;Park, Sun Young;Jung, Won Jo;Ma, Sang Hyeok;Kim, Yun Jung;Kim, Sun Ju
    • Pediatric Infection and Vaccine
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    • v.7 no.1
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    • pp.113-119
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    • 2000
  • Purpose : Rotavirus is a most common etiologic agent of pediatric gastroenteritis. The standard method to diagnose rotavirus infection was the detection of viral particles in specimens through electron microscopy. But it was complex. Enzyme immunoassay and latex agglutinin are preferred because they are relatively handy, inexpensive and take a short time, in comparison with electron microscopy. However, several reports have shown that the use of ELISA to diagnose rotavirus infection in neonates can result in false positive reactions. The main purpose of this study is to compare ELISA and RT-PCR in the diagnosis of neonatal rotavirus infection. Methods : Data presented in this study were obtained form 123 newborn babies in the nursery of the Fatima Hospital, Masan, Korea, form Jury to December, 1997. We obtained two samples of stool from each of the newborn babies and then performed the Rotazyme test and the RT-PCR. In the Rotazyme test, the results were interpreted according to visual findings. The samples were used for the RT-PCR test after at stock $-30^{\circ}C$ to identify rotavirus group A. The result of the two tests were compared. Results : The informations are divided into 73 males and females. Out of the total informations 15 were transferred from other hospitals. Their average gestational age was $38.5{\pm}1.6$ weeks. The average birth weight was $3134.8{\pm}539gm$. In the Rotazyme test, 75 samples turned out to be positive. Out of them, 55 samples(75.3%) were positive and 18 samples(24.7%) were negative in the RT-PCR. On the other hand, in the Rotazyme test, 50 samples turned out be negative. Out of them, 27 samples(54%) were positive and 23 samples(46%) were negative in the RT-PCR. Conclusion : Rotavirus infection in uncommon in neonates. The diagnosis based on visual findings using Rotazyme test has a disadvantage in the sense that it can result in false positive reactions and false negative reactions in the diagnosis of neonatal rotavirus infection.

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Comaprison of Six Serological Methods for the Diagnesis of Bovine Brucellosis (브루셀라병(病) 검색(檢索)에 사용(使用)되는 여러가지 혈청진단법(血淸診斷法)의 비교연구(比較硏究))

  • Kim, Keum-Hwa;An, Soo-Hwan;Park, Yong-Ho;Kim, Dong-Sung
    • Korean Journal of Veterinary Research
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    • v.22 no.2
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    • pp.149-153
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    • 1982
  • Results obtained from six secological tests for diagnosing bovine brucellosis-standard plate agglutination test (SPT), standard tube agglutination test(STT), complement fixation test(CFT), Rivanol test (RT), agar gel precipitation test (AGP) and counterimmunoelectrophoresis(CIEP) were compared using 38 sera from brucella reactors and 222 sera from dairy and beef cattle in field. The SPT gave 1.6% apparent false negative reactions and 15.4% apparent false positive reactions when compared with STT which is an official test for bovine brucellosis in this country. The distribution of antibody titers determined by STT showed that 37.5% of 38 reactors had antibody titers ranging from 100 to 200, and the remaining 62.5% had antibody titers of 400 or higher. when 38 reactor judged by STT were tested by CFT and RT, 32 cattle(82.4%) were positive by CFT and 33 cattle (86.8%) were positive by RT, respectively. This results suggest that RT is comparable to CFT in the diagnosis of bovine brucellosis. The results also indicated that both AGP and CIEP were insensitive to detect brucella infection in cattle.

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Efficacy of intraoperative neuromonitoring (IONM) and intraoperative indocyanine green videoangiography (ICG-VA) during unruptured anterior choroidal artery aneurysm clipping surgery

  • Chanbo Eun;Seung Joo Lee;Jung Cheol Park;Jae Sung Ahn;Byung Duk Kwun;Wonhyoung Park
    • Journal of Cerebrovascular and Endovascular Neurosurgery
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    • v.25 no.2
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    • pp.150-159
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    • 2023
  • Objective: The aim of this study was to investigate the efficacy of intraoperative indocyanine green videoangiography (ICG-VA) and intraoperative neuromonitoring (IONM) to prevent postoperative ischemic complications during microsurgical clipping of unruptured anterior choroidal artery (AChA) aneurysms. Methods: We retrospectively reviewed the clinical and radiological records of all patients who had undergone microsurgical clipping for unruptured AChA aneurysms at our institution between April 2001 and December 2019. We compared the postoperative complication rate of the group for which intraoperative ICG-VA and IONM were utilized (group B; n=324) with that of the group for which intraoperative ICG-VA and IONM were not utilized (group A; n=72). Results: There were no statistically significant differences in demographic data between the two groups. Statistically significant differences were observed in the rate of overall complications (p=0.014) and postoperative ischemic complications related to AChA territory (p=0.039). All the cases (n=4) in group B who had postoperative infarctions related to AChA territory showed false-negative results of intraoperative ICG-VA and IONM. Conclusions: Preserving the patency of the AChA is essential to minimize postoperative complications. Intraoperative monitoring tools including ICG-VA and IONM can greatly contribute to lowering complication rates. However, their pitfalls and false-negative results should always be considered.

A Case of False Negativity With COVID-19 Diagnostic Test in Total Laryngectomee (코로나바이러스 감염증-19 진단검사에 위음성을 보인 후두전절제 환자 1예)

  • Beag, Moon Seung;Kwon, Hyeok Ro;Kim, Seung Woo
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.33 no.1
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    • pp.54-57
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    • 2022
  • The coronavirus disease (COVID-19) by severe acute syndrome coronavirus-2 (SARS-CoV-2) occurs the unprecedented pandemic during recent two years and the WHO declared a global pandemic of COVID-19 in March 2020. The most common sampling sites in COVID-19 test are the oropharynx and nasopharynx. We recently encountered a total laryngectomee who had a positivity COVID-19 diagnostic test from the tracheostoma, on the other hand, false negativity from the nasal cavity. The meaning of this case is that accurate screening test could be achieved by performing a test through the tracheostoma as well as nasal cavity or oropharynx. We also would like to discuss the accurate testing methods of patients whose airflow has distorted due to surgery, the management method of these patients, and the need of further research in the COVID-19 pandemic period with relevant literature reviews.

Urinalysis: The Usefulness and Limitations of Urine Dipstick Testing (요검사: 요시험지봉 검사의 유용성과 한계)

  • Han, Tae Hee
    • Childhood Kidney Diseases
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    • v.17 no.2
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    • pp.42-48
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    • 2013
  • The urinalysis is an essential part of the diagnostic work-up for kidney disease and other renal system disorders. The dipstick test allows rapid and simultaneous chemical analyses of urine, including factors such as pH, specific gravity, protein, glucose, ketones, occult blood, bilirubin, urobilinogen, nitrite, and leukocyte-esterase. The chemical reactions on dipstick are complicated and can be affected by oxidizing, reducing, and discoloring substances in the urine. Therefore, false positive and false negative results are common in dipstick testing. To obtain reliable results with the dipstick, it is necessary to collect urine cleanly and examine the urine carefully. It is mandatory to clearly understand the principles of dipstick testing to evaluate abnormal findings. If the urine dipstick results suggest hematuria, proteinuria, or urinary tract infection, microscopy of the urine should be performed to confirm the findings.

Association between False Positive, False Negative, High-Background Cases and Humidity in One Lambda LABTypeTM HLA-DR Typing (One Lambda LABTypeTM을 이용한 HLA- DR Typing시 나타나는 위양성과 위음성, High-Background 사례와 검사실 습도의 관계분석)

  • Hyang Son AN;Minsung SOHN
    • Korean Journal of Clinical Laboratory Science
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    • v.55 no.3
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    • pp.132-142
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    • 2023
  • Human leukocyte antigen (HLA) typing was performed in the diagnostic immunology laboratory of the Seoul National University Hospital. Among 611 HLA-DR tests, specific bead reactions suspected of being false positive and false negative in Lot 20 reagents were found. Therefore, we aimed to identify the factors causing cut-off corrections by examining cases where cut-off corrections were not made for 533 test results and cases where cut-off corrections were made for 78 cases after the cut-off corrections of specific beads. Frequency analysis was conducted to verify the demographic characteristics, and descriptive statistics were used to assess the humidity in the laboratory as a variable. Cross-tabulation was done to examine the association between cut-off corrections and demographic characteristics. Independent samples t-tests were conducted to verify the difference in humidity based on cut-off corrections. Finally, logistic regression analysis was conducted to examine the relationship between humidity levels and the rate of cut-off corrections, and results showed as the humidity level in the laboratory highs, the number of cut-off corrections decreased by a factor of 0.986. This suggests cut-off corrections rate increases when the humidity lowers. Therefore, it indicates that humidity in the laboratory is also a factor that affects HLA typing results.

Retrospective Analysis Study of False-Positive Amphetamine Immunoassay Cases and Negative Cases after Withdrawal while Taking Herbal Medicine-Containing Ephedra Sinica Confirmed in a Korean Medicine Obesity Clinic (한의 비만 클리닉에서 확인된 마황 함유 한약 복용 중 암페타민 면역측정법의 위양성 사례 및 휴약 후 음성 사례의 후향적 분석연구)

  • Byungsoo Kang;Suyong Shin; Jungsang Kim; Minwhee Kang; Donghoon Lee;Seonghyeon Jeon;Minwoo Bang
    • Journal of Korean Medicine for Obesity Research
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    • v.24 no.1
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    • pp.94-101
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    • 2024
  • Herbal medicine (HM)-containing Ephedra Sinica (ES) has been associated with false-positive amphetamine immunoassay (FP IA) results. This study retrospectively evaluated the effects of dose, duration, and withdrawal instructions on FP IA and the safety of HM-containing ES at a clinic in Seoul from 2022 to 2023. The study included 6 patients in the FP IA group and 5 patients in the withdrawal instruction negative (Neg) group. The pre-test ephedrine alkaloids dose in the FP IA group was 95.17±31.90 mg, compared with 88.6±20.43 mg in the Neg group. The FP IA group had taken HM for 226.67±152.87 days before testing, and testing was performed while taking HM. In contrast, the Neg group had taken HM for 147.6±23.49 days and had 5.4±1.50 days of withdrawal period before the test following instructions of Korean medicine doctors. All adverse events (AEs) were moderate in severity, and the number of occurrences was similar: 5 in the FP IA group and 7 in the Neg group. AEs included constipation, insomnia (3 cases each), and palpitations (2 cases). The results of this study show that ES-induced FP IA can be resolved with withdrawal instructions and ES can be safely prescribed and administered by Korean medicine doctors. Further studies are needed to determine how to prevent FP IA after taking ES.

Study on Characteristics and User Reactions of Videos Related to COVID-19 Vaccine (코로나19 백신 관련 영상의 특성 및 이용자 반응에 대한 연구)

  • Lee, Mina;Hong, Juhyun
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.3
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    • pp.163-171
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    • 2021
  • This study aimed to investigate the main characteristics of the COVID-19 vaccine-related videos spread on YouTube and differences in user responses in the infodemic situation caused by COVID-19. As a result of content analysis of 579 videos related to the COVID-19 vaccine, it was found that all of the false information was written by individual channels. Institutions, organizations, media companies, and government channels reported spread of false information as well as fact-oriented reporting. The progressive channel had a high percentage of positive sentiment in favor of vaccination, and the conservative channel had a high percentage of negative emotion against vaccination. After the vaccination started, the number of videos on government channels increased, and it was found that the number of videos with positive emotions increased. Results of regression analysis of video characteristics that affect the number of likes indicated that personal expert videos and videos from progressive channels received more likes. Combining the research results, we propose a plan to promote government policies regarding the COVID-19 vaccine using social media.