• Analytical Science and Technology
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• v.27 no.6
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• pp.333-338
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• 2014

A simple and sensitive analytical method for fluoride in urine by ion selective electrode (ISE) method was presented. Traditional buffer for fluoride determination using ISE is acetate-based one. Researchers have pointed out some drawbacks of the buffer for fluoride ISE analysis, and some other buffers including citrate-ammonium buffer and MES buffer have been studied for accurate determination of fluoride in urine here. These buffers provided promising results in environmental field, and this author focused on overcoming the interference of co-existing aluminium. The results show that MES-CyDTA buffer gave the best recovery with accuracy of 95-97.5% and precision of 1.9-7.9% for reference sample of 1.8-7.8 mg/L fluoride in urine, with smaller amount of samples and shorter analysis time compared with the traditional method which used acetate buffer. The method was applied to field samples, and which showed urinary of $0.98{\pm}0.38mg/g$ creatinine for workers in electric cable manufacturing factory (n=15) and $0.59{\pm}0.30mg/g$ creatinine for non-exposed workers (n=12).

• Korean Journal of Community Nutrition
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• v.25 no.4
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• pp.317-328
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• 2020

Objectives: The objective of this study was to verify the validity of a mobile phone application (app) that applies a 24-hour dietary recall with meal photos, as a means of being a more accurate method of estimating dietary sodium intake. Methods: Of the 203 subjects enrolled, 172 subjects (84 males and 88 females) were selected for the final analysis, excluding those with an intake less than 500 kcal and urine output less than 500 ml. Dietary sodium assessment methods used for comparing with the 24-hour urinary sodium excretion are as follows: 1) face-to-face 24-hour dietary recall, 2) 24-hour dietary recall using the mobile app, 3) face-to-face 24-hour dietary recall considering liquid intakes from soup, stew, water kimchi and noodle, etc (liquid-based dishes), 4) 24-hour dietary recall using the mobile app considering liquid intakes from liquid-based dishes, and 5) food frequency questionnaire. Repeated ANOVA with Bonferroni method was used for comparing the average sodium intake, and Pearson's correlation was applied to correlate the methods used. Results: In women, no significant difference was observed in the average sodium intake between all methods. Moreover, analysis in men and total adults revealed no significant difference between the 24-hour urinary sodium secretion, and 24-hour dietary recall using the app and 24-hour dietary recall using the app considering liquid intakes. Sodium intake by food frequency questionnaire was significantly different when compared with the intake determined from 24-hour urinary sodium excretion. Sodium intake from all methods (except food frequency questionnaire) significantly correlated with values obtained from 24-hour urine sodium excretion. Conclusions: Results of this study validated a mobile phone app using a 24-hour dietary recall with meal photos to better estimate dietary sodium intakes. It is believed that further studies in the future will enable the application as a tool to more accurately determine sodium intake.

• Toxicological Research
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• v.35 no.2
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• pp.155-160
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• 2019

Zinc pyrithione (ZnPT) is a coordination complex of zinc and has been used widely as an anti-dandruff agent in shampoos. Many shampoos contain both ZnPT and EDTA, a chelating agent speculated to increase ZnPT absorption, thereby raising concerns about neurotoxicity. Here, we investigated the effect of EDTA on ZnPT absorption by direct comparison of ZnPT and pyrithione (PT) concentrations in shampoo formulations, and by pharmacokinetic analysis of ZnPT, PT, and 2-methanesulfonylpyridine (MSP), the main ZnPT metabolite, in rat plasma or urine following exposure to shampoo containing ZnPT alone or a combination of ZnPT and EDTA. Approximately 17.3% of ZnPT was converted to PT by the addition of EDTA in the shampoo formulation. Plasma ZnPT and PT concentrations were not measured up to 24 hr after treatment with shampoo containing 1% ZnPT or 1% ZnPT + 2% EDTA in all rats. However, PT amount in 24-hr urine sample, MSP concentration in plasma, and MSP amount in 24-hr urine sample were approximately 4-, 2.6-, and 2.7-fold higher, respectively, in the 1% ZnPT + 2% EDTA shampoo group than in the 1% ZnPT shampoo group. As confirmed by the formulation analysis and in vivo pharmacokinetic analysis, the exposure of ZnPT could be increased by the absorption of PT due to partial dissociation of ZnPT into PT.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.90-97
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• 2017

Androgenic anabolic steroids (AASs) are synthetic derivatives of testosterone with a common structure containing cyclopentanoperhydrophenanthrene nucleus. Their use enhances the muscle building capacity and is beneficial during performance. The AASs are one of the most abused group of substances in horse doping. Liquid chromatography tandem mass spectrometry ($LC/MS^n$) has been successfully applied to the detection of anabolic steroids in biological samples. However, the saturated hydroxysteroids viz: nandrolone, $5{\alpha}-estrane-3{\beta}$, $17{\alpha}-diol$ exhibit lower detection responses in electrospray ionisation (ESI) because of their poor ionisation efficiency. To overcome this limitation pre-column chemical derivatization has been introduced to enhance their detection responses in $LC-ESI-MS^n$ analysis. The aim of present study was to develop a sensitive method for identification and confirmation of nandrolone and its metabolite in horse urine incorporating pre-column derivatization using picolinic acid. The method consists of extraction of targeted steroid conjugates by solid phase extraction (SPE). The eluted steroid conjugates were hydrolysed by methanolysis and free steroids were recovered with liquid-liquid extraction. The resulting steroids were derivatized to form picolinoyl esters and identification was done using LC-ESI-MS/MS in positive ionization mode. The picolinated steroid adduct enhanced the detection levels in comparison to underivatized steroids.

• The Journal of Internal Korean Medicine
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• v.33 no.1
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• pp.69-82
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• 2012

Objectives : To establish objective and scientific evidence of Korean medicine (KM), the papers on Oryeong-san (Wuling-san) frequently used in medical institutions of Korean Medicine were analyzed. Methods : The papers were classified by the registration of domestic or international journals, the year of publication, experimental fields and the kinds of studies on biological activities. The therapeutic mechanism was investigated in accordance with therapeutic effect of Oryeong-san (Wuling-san). Results : Out of 57 articles selected, 16 were published in domestic journals, 17 were in Chinese journals and 24 were in Japanese journals. Most papers reported as biological activities were on improvement of renal function. Oryeong-san (Wuling-san) increased urine factor such as urine excretion and electrolyte balance while decreasing proteinuria, serum factors including creatinine, cholesterol and triglyceride. In addition, injured renal tissue was recovered normally and gene expression controlling urine excretion was down-regulated. Conclusions : Improvement of renal function could be interpreted as objective and scientific evidence for Oryeong-san (Wuling-san).

• Environmental Analysis Health and Toxicology
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• v.16 no.4
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• pp.181-188
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• 2001

A gas chromatographic method was established for the simultaneous determination of urinary nicotine and cotinine. The analytes in basified urine containing a sufficient amount of Na$_2$S0$_4$were extracted into dichloromethane by vigorous shaking. Into the transferred organic phase was added a small amount of acidified methanol (0.5 N HCI in methanol), followed by concentrating the mixture to dryness using a mild stream of nitrogen gas. The concentrate was reconstituted with methanol and the final solution analyzed using the gas chromatograph equipped with the nitrogen-phosphorus detector. The reproducibility tests showed coefficients of variation less than 11％ for both compounds. The percent recovery for both analytes ranged from 88 to 103％. The estimated method detection limits for nicotine and cotinine were 0.60 and 5.1 ng/mL, respectively. Extraction efficiencies for both nicotine and cotinine apparently declined without the addition of Na$_2$S0$_4$into the urine. Moreover, the absence of methanolic HCI in the extract resulted in almost complete evaporation of nicotine and partial loss of cotinine during the concentration process, indicating that the formation of nicotine-HCI and cotinine-HCI species is prerequisite to the suppression of the loss of both compounds.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.3
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• pp.137-141
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• 2006

The systolic and diastolic pressures in anesthetized Sprague-Dawley male rats were greatly decreased after single-dose of Cd treatment without significant changes in heart rate. There was a fluid-shift into the third space and/or -loss through the kidney, since plasma $Na^+$ concentration and hematocrit ratio were significantly increased by acute Cd exposure. The present study showed that the sustained hypotensive effect of single-dose Cd on the cardiovascular system might have resulted from the systemic hypovolemia. Furthermore, renal excretion of electrolytes, including $Na^+$ and $K^+$, and urine flow rate were increased by Cd intoxication. Interestingly, the ratio of $Na^+/K^+$ excretion was increased and reached the maximum level 3 hours after Cd injection and returned to the normal level after 7 hours. Nevertheless, there was no difference in the regression analysis of $Na^+$ excretion and urine flow rate in both groups. Therefore, the increase in the urine volume seemed to enhance the excretion of $Na^+$. This study strongly suggest that the hypotensive effect of Cd is mediated by systemic $Na^+$ loss through the kidney and/or hypovolemia via fluid-shift.

• Journal of Veterinary Clinics
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• v.21 no.3
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• pp.264-269
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• 2004

A retrospective analysis was performed with 270 cases of canine urolithiasis examined at Laboratory of Clinical Pathology, College of Veterinary Medicine, Seoul Nat'l University in the period between January 2001 and December 2003. The Shih-Tzu (64 cases), Yorkshire terrier (60 cases), miniature schnauzer (41 cases) and maltese terrier (36 cases) had higher incidences than other breeds. Canine urolithiasis occurred from 4 months to 15 years of age, but the most prevalent age was 3 years. Mean age was $5.68\pm3.14$ years. The major mineral component. of calculi was struvite (54.1%) and calcium oxalate (30.4%). There was no sex prevalences: male 131 cases, female 132 cases. The most prevalent anatomic locations of calculi were urinary bladder (53 of 131 cases), urethra (24 of 131 cases) and bladder/urethra (45 of 131 cases) in males and urinary bladder (103 of 132 Cases) in females. The major mineral component of calculi in urinary bladder was struvite (102 of 160 cases), and that in urethra (13 of 25 cases) and multiple locations (29 of 62 cases) was calcium oxalate: The major components of calculi were not always consistent with the components which could be expected from urine pH and crystals. So it is suggested that the components of the calculi must be analyzed after surgical removal to prevent the recurrence when the calculi could not be dissolved by diets or urine pH modifiers.

• Journal of Korean Physical Therapy Science
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• v.11 no.1
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• pp.28-35
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• 2004

The purpose of the present study was to investigate the effectiveness of silver spike point (SSP) low frequency electrical stimulation on glomerular filtration rate (GFR), specifically, such as diuretic action in 24 hour urine and in plasma analysis from normal volunteer. The current of 1 Hz continue type (CT) of SSP low frequency electrical stimulation significantly decreased in plasma creatine from normal volunteer. However, the urine creatinine clearance (Ccr) was significantly increased by SSP low frequency electrical stimulation in normal volunteer. These results suggest that the SSP low frequency electrical stimulation, especially current of 1 Hz continue type, significantly regulates urine creatinine clearance and glomerular filtration rate from normal volunteer. Therefore, the SSP low frequency electrical stimulation is a good regulator through a diuretic action of hypertension.

• Analytical Science and Technology
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• v.15 no.3
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• pp.185-189
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• 2002

International Olympic Committee (IOC) prohibits the use of cyclofenil for male. To prove whether cyclofenil product was taken or not, the analytical method in urine using GC/MS was established. The extraction recoveries of cyclofenil and its metabolites were higher in the range of pH 5-9. Because the parent drug (cyclofenil) was not excreted in urine, metabolites were detected and theses were used as a criteria of cyclofenil dose. Therefore the metabolites were hydrolyzed, extracted at pH 9.6, derivatized with MSTFA and analyzed by GC/MS.