• Journal of Preventive Medicine and Public Health
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• v.40 no.4
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• pp.297-304
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• 2007

Objectives : We investigated the validity of the dipstick method (Mossman Associates Inc. USA) and the expired CO method to distinguish between smokers and non-smokers. We also elucidated the related factors of the two methods. Methods : This study included 244 smokers and 50 ex-smokers, recruited from smoking cessation clinics at 4 local public health centers, who had quit for over 4 weeks. We calculated the sensitivity, specificity and Kappa coefficient of each method for validity. We obtained ROC curve, predictive value and agreement to determine the cutoff of expired air CO method. Finally, we elucidated the related factors and compared their effect powers using the standardized regression coefficient. Results : The dipstick method showed a sensitivity of 92.6%, specificity of 96.0% and Kappa coefficient of 0.79. The best cutoff value to distinguish smokers was 5-6ppm. At 5 ppm, the expired CO method showed a sensitivity of 94.3%, specificity of 82.0% and Kappa coefficient of 0.73. And at 6 ppm, sensitivity, specificity and Kappa coefficient were 88.5%, 86.0% and 0.64, respectively. Therefore, the dipstick method had higher sensitivity and specificity than the expired CO method. The dipstick and expired CO methods were significantly increased with increasing smoking amount. With longer time since the last smoking, expired CO showed a rapid decrease after 4 hours, whereas the dipstick method showed relatively stable levels for more than 4 hours. Conclusions : The dipstick and expired CO methods were both good indicators for assessing smoking status. However, the former showed higher sensitivity and specificity and stable levels over longer hours after smoking, compared to the expired CO method.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.990-992
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• 2006

In a previous study, we obtained polyclonal antibodies against the organophosphorus insecticide fenitrothion and developed an enzyme-linked immunosorbent assay (ELISA) for this pesticide. Using these antibodies and an enzyme tracer, a direct competitive ELISA method specific for fenitrothion using a dipstick format was developed. Dipstick ELISA using antibodies to fenitrothion immobilized on an Immunodyne membrane allowed the quick visual detection of fenitrothion at concentrations above $10\;{\mu}g/L$. The $IC_{50}$ value of dipstick ELISA using reflectance detection was $27\;{\mu}g/L$ with a detection limit of $2\;{\mu}g/L$. The recovery of fenitrothion from spiked lettuce and rice samples using the dipstick ELISA ranged from 87-107%.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.27-31
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• 2003

Infectious flacherie of silkworm Bombyx mori is caused by B. mori infectious flacherie virus (BmIFV) and causes severe crop loss to sericulturists. In the present study, a colloidal textile dye-based dipstick immunoassay is developed for the detection of infectious flacherie in silkworms. Colloidal textile dye (blue D2R) with Aλ$_{max}$ at 620 nm was sensitised with 500 $\mu\textrm{g}$/ml of purified anti-BmIFV IgG. The dye-antibody reagent detects purified antigen up to 10 ng/ml and BmIFV infection in diseased larval extracts $(up to a dilution of {10^-5})$ and faecal matter extracts $(up to a dilution of {10^-2})$ by forming clear blue dot within 30 min. It was observed to be stable for three months period at $4^{\circ}C$. The efficacy of textile dye-based dipstick immunoassay was on pay with HRP-based dipstick immunoassay and fluorescent antibody test, and better than latex agglutination and ouchterlony tests in the detection of BmIFV The dye-based dipstick immunoassay method provides a simple, sensitive and less expensive test for the detection of BmIFV infection in silkworms.s.

• Journal of Biosystems Engineering
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• v.33 no.5
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• pp.340-347
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• 2008

Dipstick urinalysis is used as a routine test for a screening test of UTI (urinary tract infection) in primary practice because urine dipstick test is simple. The result of dipstick urinalysis brings medical professionals to make a microscopic examination and urine culture for exact UTI diagnosis, therefore it is emphasized on a role of screening test. The objective of this study was to the classification between UTI patients and normal subjects using hybrid neural network classifier with enhanced clustering performance in urine dipstick screening test. In order to propose a classifier, we made a hybrid neural network which combines with RBF layer, summation & normalization layer and L VQ artificial neural network layer. For the demonstration of proposed hybrid neural network, we compared proposed classifier with various artificial neural networks such as back-propagation, RBFNN and PNN method. As a result, classification performance of proposed classifier was able to classify 95.81% of the normal subjects and 83.87% of the UTI patients, total average 90.72% according to validation dataset. The proposed classifier confirms better performance than other classifiers. Therefore the application of such a proposed classifier expect to utilize telemedicine to classify between UTI patients and normal subjects in the future.

• Journal of Preventive Medicine and Public Health
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• v.39 no.5
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• pp.427-432
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• 2006

Objectives: This study was to investigate if the dipstick proteinuria can predict cardiovascular mortality in a population of Korean men. Methods: We measured urine protein and other cardiovascular risk factors in 100059 Korean men, aged between 35-59 years in 1990 and 1992. Levels of proteinuria measured by dipstick method were trace or less, 1+, 2+, and 3+ or greater. The primary outcomes were deaths from all causes, cardiovascular disease, cancer, and others in a 12 year follow-up from 1993 to 2004. Results: The multivariate-adjusted relative risks (95% CI) for cardiovascular death according to the level of proteinuria (1+, 2+, 3+ and more) in 1990 examination were 2.18 (1.36-3.48), 2.55 (1.37-4.78), and 4.57 (2.16-9.66) respectively. The corresponding relative risks according to the level of proteinuria in 1992 examination were 2.49 (1.71-3.64), 2.64 (1.53-4.58), and 2.78 (1.15-6.73). The relative risks for cardiovascular death of men with proteinuria (1+ or greater) once and twice among the examinations were 2.18 (1.63-2.92) and 3.75 (2.27-6.18), compared with men without proteinuria in 1990 and 1992 examinations. Conclusions: Our results showed that dipstick proteinuria is associated with cardiovascular mortality in Korean men. Dipstick proteinuria could be a predictor for cardiovascular mortality.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.117-122
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• 1999

Purpose : We studied the correlation between urinalysis and radiologic findings in infants and children with urinary tract infection. Method : Urine Dipstick test and unstained urine microscopic examination were carried out in 56 infants and children who were hospitallized with the diagnosis of urinary infection by pocitive urine culture at Seoul Adventist from September 1996 through August 1998. Urine was collected by midsream, catheter, urine bag after cleansing or bladder puncture. Renal sonography and $^{99m}Tc-DMSA$ renal scan or voiding cystoureterography were studied. Results : 1)In dipstick analysis, leukocyte esterase(LE) were positive in 30 cases of 56 patients(54%) and Nitrite were positive in 20 cases of 56 patients(36%) and LE or Nitrite were positive in 38 cases of 56 children with UTI(68%). 2)In microscopic analysis, WBC were positive in 38 cases of patients(68%) and bacteria were positive in 23 cases of 56 patients(41%) and WBC or bacteria were positive in 41 cases of 56 children with UTI(71%). 3)Ten cases of 56 UTI patients(18%) showed negative finding in Dipstick and microscopic analysis. 4)There was no significant difference in positive rate of dipstick(71% vs 66%) and microscopia analysis(83% vs 66%) between two group with or without renal scar on $^{99m}Tc-DMSA$ scan (P=0.117). 5)There was no significnt difference in positive rate of dipstick(100% vs 91%) and microscopic analysis(100% vs 100%) between two groups with or without vesicoureteral reflux on VCUG. Conclusion : There was no specific relationships between the abnormal urinalysis and the abnormal findings on $^{99m}Tc-DMSA$ scan or VCUG.

• Childhood Kidney Diseases
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• v.26 no.2
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• pp.69-73
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• 2022

Proteinuria is an early hallmark of kidney disease and a major risk factor for systemic cardiovascular diseases. There are several methods to measure proteinuria, such as the urine dipstick test, 24-hour urinary protein excretion method, and spot urine for the protein-to-creatinine ratio. The urine dipstick test is simple but inaccurate. The 24-hour urinary protein excretion method is the gold standard; however, it is cumbersome, especially in children. Spot urine for the protein-to-creatinine ratio is simple and accurate, but has limitations. Specific urinary protein such as albumin can be measured instead of the total protein content. Tests should be avoided in situations that cause transient proteinuria or false-positive results. It should be performed correctly, and its limitations should be recognized and interpreted accurately.

• Journal of Sensor Science and Technology
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• v.19 no.3
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• pp.169-175
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• 2010

Urinalysis is an important clinical test to diagnose urinary diseases, and dipstick method with visual inspection is widely applied in practice. Automated optical devices recently developed have disadvantages of long measurement time, big size and heavy weight, accuracy degradation with time, etc. The present study proposed a new computer scanning technique, in which the test strip and the standard chart were simultaneously scanned to remove any environmental artifacts, followed by automated differentiation with the minimum distance algorithm, leading to significant enhancement of accuracy. Experiments demonstrated an accuracy of 100 % in that all test results were identical with the human visual inspection. The present technique only uses a personal computer with scanner and shortens the test time to a great degree. The results are also stored and accumulated for later use which can be transmitted to remote locations through a network, thus could be easily integrated to any ubiquitous health care systems.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.454-464
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• 2019

Salmonellosis is a highly contagious bacterial disease that threatens both human and poultry health. Tests that can detect Salmonella in the field are urgently required to facilitate disease control and for epidemiological investigations. Here, we combined loop-mediated isothermal amplification (LAMP) with a chromatographic lateral flow dipstick (LFD) to rapidly and accurately detect Salmonella. LAMP primers were designed to target the Salmonella invA gene. LAMP conditions were optimized by adjusting the ratio of inner to outer primers, $MgSO_4$ concentration, dNTP mix concentration, amplification temperature, and amplification time. We evaluated the specificity of our novel LAMP-LFD method using six Salmonella species and six related non-Salmonella strains. All six of the Salmonella strains, but none of the non-Salmonella strains, were amplified. LAMP-LFD was sensitive enough to detect concentrations of Salmonella enterica subsp. enterica serovar Pullorum genomic DNA as low as $89fg/{\mu}l$, which is 1,000 times more sensitive than conventional PCR. When artificially contaminated feed samples were analyzed, LAMP-LFD was also more sensitive than PCR. Finally, LAMP-LFD gave no false positives across 350 chicken anal swabs. Therefore, our novel LAMP-LFD assay was highly sensitive, specific, convenient, and fast, making it a valuable tool for the early diagnosis and monitoring of Salmonella infection in chickens.

• Journal of Microbiology and Biotechnology
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• v.31 no.12
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• pp.1672-1683
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• 2021

Vibrio parahaemolyticus is recognized as one of the most important foodborne pathogens responsible for gastroenteritis in humans. The bla_CARB-17 gene is an intrinsic β-lactamase gene and a novel species-specific genetic marker of V. parahaemolyticus. In this study, a loop-mediated isothermal amplification (LAMP) assay combined with a lateral flow dipstick (LFD) was developed targeting this bla_CARB-17 gene. The specificity of LAMP-LFD was ascertained by detecting V. parahaemolyticus ATCC 17802 and seven other non-V. parahaemolyticus strains. Finally, the practicability of LAMP-LFD was confirmed by detection with V. parahaemolyticus-contaminated samples and natural food samples. The results showed that the optimized reaction parameters of LAMP are as follows: 2.4 mmol/l Mg²⁺, 0.96 mmol/l dNTPs, 4.8 U Bst DNA polymerase, and an 8:1 ratio of inner primer to outer primer, at 63℃ for 40 min. The optimized reaction time of the LFD assay is 60 min. Cross-reactivity analysis with the seven non-V. parahaemolyticus strains showed that LAMP-LFD was exclusively specific for V. parahaemolyticus. The detection limit of LAMP-LFD for V. parahaemolyticus genomic DNA was 2.1 × 10^-4 ng/μl, corresponding to 630 fg/reaction and displaying a sensitivity that is 100-fold higher than that of conventional PCR. LAMP-LFD in a spiking study revealed a detection limit of approximately 6 CFU/ml, which was similar with conventional PCR. The developed LAMP-LFD specifically identified the 10 V. parahaemolyticus isolates from 30 seafood samples, suggesting that this LAMP-LFD may be a suitable diagnostic method for detecting V. parahaemolyticus in aquatic foods.