• Title/Summary/Keyword: test specificity

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Diagnostic Value of Dipstick Urinalysis (Leukocyte Esterase and Nitrite) as a Screening Test for Urinary Tract Infection in Acute Febrile Children (급성 발열 환아에서 요로감염 선별검사로서 Dipstick 요분석(Leukocyte esterase와 Nitrite)의 진단적 가치)

  • Hwang Soo-Ja;Park So-Young;Kim Hye-Soon;Park Eun-Ae;Kim Ho-Sung;Seo Jung-Wan;Lee Seung-Joo
    • Childhood Kidney Diseases
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    • v.2 no.1
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    • pp.1-8
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    • 1998
  • Purpose : To evaluate the diagnostic value of dipstick urinalysis($Multistix^{(R)}$) as a screening test for urinary tract infection(UTI) in acute febrile children. Methods : We compared dipstick uinalysis (leukocyte estease(LE) and nitrite) with microscopic urinalysis (WBC and bacteria) and urine culture in 80 children with UTI and 605 children without UTI, who were admitted due to acute fever at EWHA Womans University Hospital between Oct. 1994 and Feb. 1996. Results : 1) In dipstick urinalysis, LE and nitrite were positive in 38.7%, and 13.8% of 80 children with UTI and in 2.1%. and 1.2% of 605 children without UTI. 2) In microscopic urinalysis, WBC and bacteria were positive in 31.2%, and 17.5% of 80 children with UTI and in 4.1%, and 0.6% of 605 children without UTI. 3) Positive rate of LE on dipstick urinalysis was 38.7%, which was significantly higher than 31.5% of WBC on microscopic urinalysis (P<0.05). Positive rate of nitrite was not significantly different to that of bacteria. 4) Sensitivity, specificity, positive predictive value, negative predictive value of dipstick urinalysis were 43.7%, 98.3%, 63.6%, 92.9% which were not significant different to 40.0%, 99.0%, 54.0%, 92.3% of microscopic urinalysis. The sensitivity of combined dipstick and microscopic urinalysis were still low(50%). 5) Additional positive rate of microscopic urinalysis to negative dipstick urinalysis was 6.3%(5/80) in 80 children with UTI. Conclusion : The sensitivity of dipstick urinalysis was low and additional value of microscopic urinalysis was minimal in febrile UTI. So urine culture is mandatory in acute febrile children even though dipstick and microscopic urinalysis are negative.

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Evaluation of Cerebral Aneurysm with High Resolution MR Angiography using Slice Interpolation Technique: Correlation wity Digital Subtraction Angiography(DSA) and MR Angiography(MRA) (Slice Interpolation기법의 고해상도 자기공명혈관조영술을 이용한 뇌동맥류의 진단 : 디지탈 감산 혈관조영술과 자기공명 혈관조영술의 비교)

  • ;;;Daisy Chien;Gerhard Laub
    • Investigative Magnetic Resonance Imaging
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    • v.1 no.1
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    • pp.94-102
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    • 1997
  • Purpose: There have been some efforts to diagnose intracranial aneurysm through a non-invasive method using MRA, although the process may be difficult when the lesion is less than 3mm. The present study prospectively compares the results of high resolution, fast speed slice interpolation MRA and DSA thereby examing the potentiality of primary non-invasive screening test. Materials and Methods: A total of 26 cerebral aneurysm lesions from 14 patients with subarachnoid hemorrhage from ruptured aneurysm (RA) and 5 patients with unruptured aneurysm(UA). In all subjects, MRA was taken to confirm the vessel of origin, definition of aneurysm neck and the relationship of the aneurysm to nearby small vessels, and the results were compared with the results of DSA. The images were obtained with 1.5T superconductive machine (Vision, Siemens, Erlangen, Germany) on 4 slabs of MRA using slice interpolation. The settings include TR/TE/FA=30/6.4/25, matrix $160{\times}512$, FOV $150{\times}200$, 7minutes 42 seconds of scan time, effective thickness of 0.7 mm and an entire thickness of 102. 2mm. The images included structures from foramen magnum to A3 portion of anterior cerebral artery. MIP was used for the image analysis, and multiplanar reconstruction (MPR) technique was used in cases of intracranial aneurysm. Results: A total of 26 intracranial aneurysm lesions from 19 patients with 2 patients having 3 lesion, 3 patients having 2 lesions and the rest of 14 patients having 1 lesion each were examined. Among those, 14 were RA and 12 were UA. Eight lesions were less than 2mm in size, 9 lesions were 3-5mm, 7 were 6-9mm and 2 were larger than IOmm. On initial exams, 25 out of 26 aneurysm lesions were detected in either MRA or DSA showing 96% sensitivity. Specificity cannot be estimated since there was no true negative of false positive findings. When MRA and MPR were used concurrently for the confirmation of size and shape, the results were equivalent to those of DSA, while in the confirmation of aneurysm neck and parent vessels, the concurrent use of MRA and MPR was far superior to the sole use of either MRA or DSA. Conclusion: High resolution MRA using slice interpolation technique showed equal results as those of DSA for the detection of intracranial aneurysm, and may be used as a primary non-invasive screening test in the future.

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Analysis of Diflubenzuron in Agricultural Commodities by Multiresidue Method (동시 다성분 분석법에 의한 농산물 중 Diflubenzuron 분석)

  • Park, Sun-Hee;Han, Chang-Ho;Kim, Ae-Kyung;Shin, Jae-Min;Lee, Jae-Kyoo;Park, Young-Hae;Kim, Ji-Min;Hwang, Lae-Hong;Chang, Min-Su;Song, Mi-Ok;Park, Ju-Sung;Yun, Eun-Sun;Kim, Mu-Sang;Jung, Kweon
    • The Korean Journal of Pesticide Science
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    • v.18 no.4
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    • pp.269-277
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    • 2014
  • The multiclass pesticide multiresidue method for the simultaneous determination of diflubenzuron in agricultural products was conducted by using HPLC-UVD. The method was validated through the guidelines of linearity, specificity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision with pesticide-free spinach, Korean cabbage, eggplant, squash, sweet pepper, cucumber, Korean melon. The calibration curve of diflubenzuron was linear over the concentration range of 0.05-5 mg/kg with correlation coefficient of above 0.99999. The limit of detection and quantification was 0.008 and 0.02 mg/kg. Mean recoveries of diflubenzuron for each sample were 77.5-105.6%. Relative standard deviation (RSD) in recoveries were all less than 20%. The intra-day and inter-day precision (RSD) were 0.4-1.9% and 0.7-1.9%, respectively. The result of validation indicated that this method was accurate and rapid assay.

Development of Immunochromatography for Detection of Escherichia coli O157:H7 Contaminated in Meats and Sprouts (육류 및 새싹채소에 오염된 Escherichia coli O157:H7의 신속검출을 위한 면역크로마토그래피법의 개발)

  • Lee, Won-Gyeong;Ryu, Hee-Jeong;Song, Jeong-Un;Kim, Kyeong-Yeol;Chung, Do-Yeong;Kim, Jeong-Sook;Shim, Won-Bo;Chung, Duck-Hwa
    • Korean Journal of Food Science and Technology
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    • v.43 no.5
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    • pp.618-623
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    • 2011
  • Escherichia coli O157:H7 has been considered as a significant food-borne pathogen since its role in causing hemorrhagic colitis and hemolytic uremic syndrome in humans was recognized. In this study, we developed an immunochromatography (ICG) assay for the detection of E. coli O157:H7. E. coli O157:H7 monoclonal antibody (EC MAb) and colloidal gold were conjugated and its specificity was determined by the ICG treated with EC MAb and antimouse IgG at test and control lines, respectively. The detection limit of the ICG was $1{\times}10^5$ CFU/mL, and no crossreactivity was observed to other E. coli strains and major food-borne pathogens. To determine the minimum enrichment time for the ICG, meats and sprouts were inoculated with $1{\times}10$ CFU/100 ${\mu}L$ of E. coli O157:H7. After enrichment time of 10 and 2 h for meats and sprouts, respectively, up to $1{\times}10$ CFU/100 ${\mu}L$ of E. coli O157:H7 could be detected by ICG.

Development of an Eating Habit Checklist for Screening Elementary School Children at High Risk of Energy Overintake (초등학생의 에너지 과잉섭취 위험 진단을 위한 식습관평가표 개발)

  • Yon, Mi-Yong;Hyun, Tai-Sun
    • Journal of Nutrition and Health
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    • v.41 no.5
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    • pp.414-427
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    • 2008
  • The purpose of the study was to develop an eating habit checklist for screening elementary school children at high risk of energy overintake. Dietary habits, food intake, anthropometric data were collected from 142 children (80 boys and 62 girls) in the 4th to 6th grades of elementary schools. Energy intake, fat intake, and percentage of Estimated Energy Requirement (%EER) were used as indices to detect the risk of energy overintake of the children. Pearson correlation coefficients were calculated between dietary habit scores and energy overintake indices in order to select questions included in the checklist. TV watching during the meal, meal speed, meal amount, overintake frequency, eatingout frequency, snack frequency, frequency of eating Ramyun or fast foods showed significant correlations with energy overintake indices. Stepwise regression analysis was performed to give each item a different weight by prediction strength. To determine the cut-off point of the test score, sensitivity, specificity, and positive predictive values were calculated. The 7-item checklist with test results from 0 to 13 points was developed, and those with equal or higher than 5 points were diagnosed as a risk group of energy overintake. Among our subjects 13.4% was diagnosed as the risk group. Mean energy intake of the subjects in the risk group and the normal group were 2,650 kcal and 1,640 kcal, respectively. However, there were no significant differences of Index of Nutritional Quality (INQ) of the other nutrients except eating fiber between the risk group and the normal group. This checklist will provide a useful screening tool to identify children at high risk of energy overintake.

Development of an Eating Habit Checklist for Screening Elementary School Children at Risk of Inadequate Micronutrient Intake (초등학생의 미량영양소 섭취부족 위험 진단을 위한 간이 식습관평가표 개발)

  • Yon, Mi-Yong;Hyun, Tai-Sun
    • Journal of Nutrition and Health
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    • v.42 no.1
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    • pp.38-47
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    • 2009
  • The purpose of the study was to develop an eating habit checklist for screening elementary school children at risk of inadequate micronutrient intake. Eating habits, food intake, and anthropometric data were collected from 142 children (80 boys and 62 girls) in the $4^{th}$ to $6^{th}$ grades of elementary schools. Percentage of Recommended Intakes (RI) and Mean Adequacy Ratio (MAR) of six micronutrients; vitamin A, riboflavin, vitamin C, calcium, iron, zinc, and the number of nutrients the children consumed below EAR among the six nutrients were used as indices to detect the risk of inadequate micronutrient intake. Pearson correlation coefficients were calculated between eating habit scores and inadequate micronutrient intake indices in order to select questions included in the checklist. Meal frequency, enough time for breakfast, regularity of dinner, appetite, eating frequencies of Kimchi, milk, fruits and beans showed significant correlations with indices of inadequate micronutrient intake. Stepwise regression analysis was performed to give each item a different weight by prediction strength. To determine the cut-off point of the test score, sensitivity, specificity, and positive predictive values were calculated. The 8-item checklist with test results from 0 to 12 points was developed, and those with equal or higher than 6 points were diagnosed as high-risk group of inadequate micronutrient intake, and those with 4 or 5 points were diagnosed as moderate-risk group. Among our subjects 14.1% was diagnosed as high-risk group, and 30.3% as moderate-risk group. The proportions of the subjects who consumed below EAR of all micronutrients but vitamin C were highest in the high-risk group, and there were significant differences in the proportions of the subjects with intake below EAR of all micronutrients except vitamin B6 among the three groups. This checklist will provide a useful screening tool to identify children at risk of inadequate micronutrient intake.

Vitamin C Quantification of Korean Momordica charantia by Cultivar, Harvest Time, and Maturity (국내산 여주의 지역별, 수확시기별, 숙기별 Vitamin C 함량)

  • Jeong, Yun Sook;Lee, Sang Hoon;Song, Jin;Hwang, Kyung-A;Noh, Geon Min;Hwang, In Guk
    • The Korean Journal of Food And Nutrition
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    • v.29 no.4
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    • pp.474-479
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    • 2016
  • This study aimed to investigate the concentration of vitamin C in Momordica charantia (MC) by cultivar, harvest time, and maturity. The methods for determining vitamin C levels were validated by measuring their linearity, specificity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy using HPLC. Results showed high linearity in the calibration curve, with a coefficient of correlation ($R^2$) of 0.9994. The LOD and LOQ values for vitamin C were 0.05 and $0.16{\mu}g/mL$, respectively. The relative standard deviations (RSDs) for intra- and inter-day precision of vitamin C measurements were 2.34 and 1.34%, respectively. Depending on cultivar, the concentration of vitamin C in MC varied from 20.75~107.31 mg/100 g, fresh weight, with an average level $68.85{\pm}25.57mg/100g$, FW. When MC was analyzed by harvest time, the 20150612 MC showed the highest amount of vitamin C ($113.20{\pm}1.89mg/100g$, FW). On the other hand, the highest vitamin C content by maturity was $48.59{\pm}0.87mg/100g$, FW (15 day old MC). This information on the comparative vitamin C levels of MC might be useful to food scientists and should be explored for functional food development.

Residue Studies of Difenoconazole and Thiamethoxam during Cultivation of Sweet Persimmon for Export (수출용 단감에 대한 Difenoconazole과 Thiamethoxam의 잔류특성 연구)

  • Chang, Hee-Ra;Kang, Hae-Rim;Do, Jung-A;Oh, Jae-Ho;Hwang, In-Kyun;Kwon, Ki-Sung;Im, Moo-Hyeog;Kim, Kyun
    • Korean Journal of Environmental Agriculture
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    • v.31 no.3
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    • pp.248-254
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    • 2012
  • BACKGROUND: In order to elucidate residual characteristics of difenoconazole and thiamethoxam by treatment to sweet persimmons for one year and to generate the data for the maximum residue limit (MRL) establishment for those pesticides in or on sweet persimmon. METHODS AND RESULTS: Systemic fungicide difenoconazole WP (10% a.i.) and systemic insecticide thiamethoxam WG (10% a.i.) were sprayed onto 12~25-years-old sweet persimmons according to its preharvest interval (PHI), respectively, and then fresh sweet persimmons were harvested at 0, 1, 3, 7, 14, 21 days after treatment from pesticide-sprayed plots at each 3 sites. The analytical methods were evaluated to limit of quantification, linearity, specificity, reproducibility and recoveries. The crop samples were extracted with acetone and performed dichloromethane partition process. The extracted samples of difenoconazole were analyzed by GC-ECD and the thiamethoxam extracted samples were analyzed by HPLC with good sensitivity and selectivity of the method. The average recoveries of difenoconazole ranged from 87.5 to 99.5% with the percentage of coefficient variation in the range 4.1~7.6% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg). And the average recoveries of thiamethoxam and clothianidin ranged from 88.8 to 98.9% and 83.2 to 96.6% with the percentage of coefficient variation in the range 3.6~5.0% and 3.8~9.4% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg), respectively. The residue amounts ranges of difenoconazole were 0.2~0.56 mg/kg and the residue amount was decreased below the MRL level, 1.0 mg/kg, after 1 day harvest. The residue amounts ranges of thiamethoxam were 0.08~0.28 mg/kg and the residue amount was decreased below the MRL level, 0.5 mg/kg, after 1 day harvest. And the residue amount of clothianidin was below then 0.03 mg/kg for only one test site of 14 and 28 day samples. CONCLUSION: As a result, the residual amounts of difenoconazole and thiamethoxam were not exceeded the MRL of established criteria for sweet persimmon. The biological half-lives of difenoconazole and thiamethoxam were 13.6, 19.4, 16.3 and 10.0, 15.3, 14.0 days at each three test sites, respectively.

Study of Serious Bacterial Infections in Febrile Infants Younger than Three Months of Age (열이 있는 3개월 이하의 영아에서 세균성 감염의 예측에 대한 연구)

  • Jeon, Myeoung Won;Lee, Ji Young;Jang, Young Taek
    • Pediatric Infection and Vaccine
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    • v.10 no.2
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    • pp.215-222
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    • 2003
  • Purpose : This study was to analyze serious bacterial infections in infants younger than three months of age and to review the direction of treatments for these patients. Methods : 378 febrile infants with a rectal temperature ${\geq}38.0^{\circ}C$ visited from Jan. 2001 through Dec. 2002 were retrospectively studied. Infants with the following criteria belonged to the low risk group. WBC $5,000{\sim}15,000/mm^3$, WBC negative in urine stick test and negative for nitirite test, CSF WBC < $10/mm^3$ and negative in CSF gram stain, negative chest X-ray, stool WBC <5/HFP(high power field), and focal infection. If any of the above criteria were not met, they belonged to the high risk group. SBI was defined as a positive culture of urine, blood or CSF. SI was defined as aseptic meningitis or pneumonia including above laboratory tests of SBI. SBI patients were separately compared with two groups, high risk and low risk. Results : Of the 378 infants that were tested 216(57.1%) were in the high risk group and 162(42.9%) in the low risk group. Among 105 SBI(27.8%) and 172 SI(45.5%), there were 98 urinary tract infection(25.2%), 10 bacteremia(2.6%), 2 bacterial meningitis(0.6%), and 77 aseptic meningitis(22.8%). There were 76 SBI(35.2%) from the high risk group and 29 SBI(17.9%) from the low risk group identified. The results of the sensitivity(72.4%), the specificity(48.7%), the negative predictive value(82.1%) and the positive predictive value (35.2%) were calculated. Conclusion : Even though the probability of SBI in the low risk group is insignificant, it should still be considered in febrile infants younger than 3 months of age. I believe the CSF study is necessary because of the moderate high incidence of abnormal finding in our study.

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Soluble Interleukin-2 Receptor(sIL-2R) Levels in Patients Tuberculous Pleurisy VS Nontuberculous Pleurisy (결핵성 늑막삼출과 비결핵성 늑막삼출에서의 가용성 Interleukin-2 수용체의 농도)

  • Lim, Hyun-Oak;Ham, Jong-Yeol;Shim, Dae-Seok;Hwang, Young-Sil
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.2
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    • pp.135-143
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    • 1994
  • Background: The cell mediated immunity has an important role in the pathogenesis of tuberculosis. sIL-2R has been known as a sensitive marker of T lymphocyte activation Elevated serum levels of sIL-2R have been found in patients with lymphoproliferative disorders, organ transplantation, autoimmune diseases, and various granulomatous diseases. Elevated levels of sIL-2R have been also found in the serum and pleural fluid of the patients with tuberculosis. To evaluate the diagnostic value of sIL-2R in the differentiation of tuberculous pleurisy and nontuberculous pleurisy. We measured the level of sIL-2R in the sera and pleural fluids of 12 patients with tuberculous pleurisy and 32 patients with nontuberculous pleurisy. Method: Samples of pleural fluid and serum were centrifuged at 2500 rpm for 10 min to remove cell pellets. Soluble IL-2R was measured with a sandwitch enzyme immunoassay using the Cellfree(r) Interleukin-2 Receptor Test kit(T-cell science,Inc. Cambridge, MA). Results: The results obtained were as follows: 1) The sIL-2R level in pleural fluid of the patients with tuberculous pleurisy was higher than that of patients with nontuberculous pleurisy(P<0.005). 2) When the sIL-2R level above 5,000 u/ml in pleural fluid was used as the cut-off value to diagnose tuberculous pleurisy, it had a sensitivity of 84.6% and a specificity of 90.9%. 3) The sIL-2R level in the sera of the patients with tuberculous pleurisy was higher than that of patients with bacterial pleural effusions and normal control group(P<0.05) and there was no difference of levels compared with malignant pleural effusions and transudative pleural effusions(P>0.05). 4) In patients with tuberculous pleurisy, the mean concentration of sIL-2R in pleural fluid was higher than that in serum(P<0.005). Conclusion: These findings suggest that the measurement of elevated levels of pleural fluid sIL-2R in tuberculous pleurisy may be useful in the differential diagnosis between patients with tuberculous pleurisy and nontuberculous pleurisy.

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