• 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.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.122-122
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• 2009

금속기판과 액체금속의 젖음성은 일반적으로 액적법 (sessile drop)에 의해 고체와 액체간의 접촉각 측정을 통해서 알 수 있다. 이러한 방법에 의한 젖음성 실험결과는 고체와 액체계면에서의 반응이 무시될 수 있는 경우에 적용가는 하지만 연속용용도금공정과 같이 용융된 금속내부로 강판이 인입되는 과정에서 계면반응이 동적으로 진행되는 과정에서의 젖음성을 모사하기에는 이러한 방법의 신뢰성이 떨어지는 문제점이 있다. 따라서 본 연구에서는 실제 용융도금공정과 유사하게 소둔열처리된 저탄소강판이 환원성분위기내에서 Zn 및 Zn-Al 용융도금욕 내부로 연속적으로 인입되는 과정에서의 젖음력 및 접촉각 등의 측정을 통해 실제 도금공정상의 도금성과 젖음성의 연관성을 규명하고자하였다. 연구결과 일반적인 Zn 도금욕의 경우 젖음성이 양호하지만 Al함량이 높은 경우에는 젖음성이 좋지 못한 것으로 나타났다.

• 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.

• 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.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.311-320
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• 1999

Background: In recent years, tuberculosis has re-emerged as a major health problem in both industrialized & developing countries. Recent advances in identifying & purifying antigens secreted in active tuberculosis infection have lead to the development of serological assays based on a number of immunodominant antigens. To date, the most sensitive and specific of these antigens has been the 38-kDa antigen. Method: Two rapid membrane-based serologic assays using antigen(38-kDa) from mycobacterium tuberculosis for the diagnosis of tuberculosis were evaluated in 22 patients with smear-positive pulmonary tuberculosis, 14 patients with inactive pulmonary tuberculosis, and 9 patients with non-tuberculous lung disease. Result: The evaluation of validity(sensitivity, specificity, positive predictive value, negative predictive value, false positivity and false negativity) of STAT-PAK ULTRA FAST$^{(R)}$ were 77.3%, 28.6%, 63.0%, 44.4%, 71.4 %, and 22.7% for differential diagnosis of active pulmonary tuberculosis and inactive pulmonary tuberculosis, respectively. The evaluation of validity of STAT-PAK ULTRA FAST$^{(R)}$ were 77.3%, 33.3%, 73.9%, 37.5%, 66.7%, and 22.7% for differential diagnosis of active pulmonary tuberculosis and non-tuberculosis. The evaluation of validity of ICT Tuberculosis$^{(R)}$ were 54.5%, 57%, 66.7%, 44.4%, 42.9%, and 45.5% for differential diagnosis of active pulmonary tuberculosis and inactive pulmonary tuberculosis. The evaluation of validity of ICT Tuberculosis$^{(R)}$ were 54.5%, 100%, 100%, 47.4%, 0%, and 45.4% for differential diagnosis of active pulmonary tuberculosis and non-tuberculosis. Conclusion: We concluded no effectiveness of STAT-PAK ULTRA FAST$^{(R)}$ & ICT tuberculosis$^{(R)}$on serologic diagnosis of pulmonary tuberculosis. In the future, further large-scale study should be needed for serologic diagnosis of pulmonary tuberculosis.

• Proceedings of the KSLP Conference
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• 1997.11a
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• pp.263-263
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• 1997

성대결절, 폴립, 부종 등은 성대의 남용이나 과용등의 성대손상이 그 공통된 주된 원인으로 거론되고 있다. 하지만 음성치료를 비롯한 보존적 치료에 대한 반응이 서로 상이하며, H＆E 염색을 이용한 병리조직학적인 감별이 곤란하여 진단에 혼돈이 있으며, 치료의 방침을 결정하거나 예후를 예측함에 있어서도 어려움이 있다. 양성성대질환은 기저막부 위와 세포외 간질에 주된 변화가 발생함이 알려져 있고, collagen type IV의 발현양상이 성대결절과 폴립에서 서로 다름에 대하여는 보고된 바 있으나 기타 점막하층의 골격유지를 주기능으로 하는 대표적 세포외간질인 collagen subtype에 대하여는 아직 보고된 바가 없는 실정이다. Collagen 발현의 차이를 연구하는 것은 상기질환의 병인을 이해하고 질환분류의 guideline을 제시하며 나아가 적절한 치료방범을 제시하는 데에 큰 의미가 있을 것으로 기대된다. Paraffin에 고정되어 있는 5례 이상씩의 성대결절과 성대폴립, 육아 종 및 라인케씨 부종 조직을 collagen type I부터 VII에 대하여 peroxidase kit를 사용하여 염색한 후 각 군간에 collagen 분포양상과 발현정도에 차이가 있는가 비교하였다.

• 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.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.408-413
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• 2010

Purpose : We aimed to prove the relative limitation of $^{99m}Tc-DMSA$ scintigraphy (DMSA) compared to computed tomography (CT) in diagnosing acute pyelonephritis (APN) in children. Methods : Since September 2006, after a 64-channel CT was imported, 10 DMSA false-negative patients have been identified: these patients underwent a CT scan for acute abdomen or acute febrile symptoms and were diagnosed as having APN; however, their DMSA scans were clear. We focused on these 10 DMSA false-negative patients and analyzed their clinical findings and CT results. We used Philips Brilliance Power 64-channel CT scanner for the CT scan and Siemens Orbitor Nuclear Camera 60 Hz for the DMSA scan. Results : The 10 DMSA false-negative patients were mostly males (80%) and infants (80%). They had fever for a mean of 1.1-day duration before admission and showed increase in acute reactants: leukocyte, erythrocyte sedimentation rate, and C-reactive protein. The CT findings of renal lesions were focal in 6 (60%) cases and diffuse in 4 (40%) cases, and most of the lesions were unilateral in 80% of patients. CT proved that 22 renal lesions were neglected by DMSA. Differential renal function test by DMSA was also of no use in the evaluation of renal lesions. Conclusion : In this study, DMSA scan showed limitation in finding renal cortical lesions of CT-proven APN patients. DMSA false-negative results seem to occur at early-phase disease of infantile age, but more prospective studies are needed to determine the reasons and their prevalence.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.562-568
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• 1998

Various diagnostic methods, such as electric pulp test, cold test, test cavity etc., have been used to determine the pulp vitality. At least two or more methods should be used with supplemental information to diagnose each case because using one method doesn't provide sufficient accuracy. These conventional methods have depended on nervous responses, but Laser Doppler Flowmeter determines the pulp vitality by measuring pulpal blood flow. In this case, we tested the vitality of the traumatized teeth with incomplete root apices and autotransplanted teeth with conventional methods and Laser Doppler Flowmeter. Conventional methods, such as electric pulp test and cold test can produce various responses according to the development state of the pulpal nerve and the sensory threshold of the patient. But, Laser Doppler Flowmeter has a lower false response rate than any other pulp vitality test methods and it can determine the vitality somewhat earlier than the other method.

• Clinical and Experimental Pediatrics
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• v.51 no.5
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• pp.492-499
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• 2008

Purpose : Helicobacter pylori infection is one of the most common gastrointestinal infections worldwide; it almost invariably causes chronic gastritis. Pediatric studies may provide important insights into the mucosal immune response of H. pylori-infection, as children are not submitted to environmental factors such as alcohol, tobacco and anti-inflammatory medication. The aim of the present study was to investigate the mucosal immune response against H. pylori in clinically well-defined groups: H. pylori-positive (divided into peptic ulcer disease and gastritis) and H. pylori-negative control. Methods : Antral biopsies were obtained from 45 children undergoing an upper GI endoscopy for dyspeptic symptoms. T cells (CD3+, CD4+, CD8+) and B cells (CD20+) were analyzed by quantitative immunohistochemistry. The correlation of lymphocyte subsets of gastric mucosa with histology was evaluated. Results : T cells (CD3+, CD4+, CD8+) and B cells (CD20+) were significantly increased in the lamina propria of H. pylori-positive group (P<0.01). CD8+ T cells were significantly increased in the lamina propria of the H. pylori-positive peptic ulcer disease (P<0.01). Within the epithelium, only CD4+ T cells were significantly increased in the H. pylori-positive group (P<0.01). Gastric histological parameters had a closer correlation with lymphocytes in the lamina propria than intraepithelial lymphocytes. Conclusion : This study suggests that both T cells and B cells in the lamina propria play important roles in the local immune response of H. pylori-infected children. Furthermore, it remains to be elucidated whether CD8+ T cells in the lamina propria may contribute to peptic ulcer formation in H. pylori-infected children.