• YAKHAK HOEJI
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• v.42 no.5
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• pp.473-479
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• 1998

Lovastatin (LOVA), a fungal metabolite isolated from cultures of Aspergillus terreus, is a competitive HMG-CoA reductase inhibitor used for the treatment of primary hyper cholesterolemia, and has also been shown to suppress growth in a variety of non-glioma tumor cell lines. A sensitive reversed-phase high-perfonnance liquid chromatographic method with ultraviolet (UV) absorbance detection has been developed to quantitate LOVA in human plasma and urine samples using liquid-liquid extraction procedure. Baseline separation of LOVA and internal standard, simvastatin was achieved on a Novapak $C_{18}$ analytical column with a mobile phase containing 0.025M $NaH_2PO_4$: CAN (35:65, v/v%), adjusted pH to 4.5. The flow rate was set at 1.5ml/min, and the column effluent was monitored by a UV detection at 238nm. The limit of quantification was determined to be 0.5${\mu}$g/ml while extraction efficiency of LOVA ranged from 73.4-82.9% at LOVA concentrations of 0.5 to 10${\mu}$g/ml. Good linearity with correlation coefficients greater than 0.999 was obtained in the range of LOVA concentrations from 0.5 to 10${\mu}$g/ml. The accuracy and the precision were proven excellent with relative standard deviation (RSD, %) and relative error (RE, %) of less than 4.2 and 4.0, respectively. Intraday precision, evaluated at five LOVA concentrations (0.5, 1, 2, 5, 10${\mu}$g/ml) and expressed as RSD ranged from 0-1.82% while the interday precision at the same concentrations ranged from 0.7-10.5%. The analytical method described was then successfully employed for the determination of LOVA concentrations in plasma samples obtained during a phase II clinical trial using high doses of LOVA (30-40mg/kg/day). This method could be further utilized for the ongoing pharmacolkinetic studies and therapeutic drug monitoring of the high-dose LOVA therapy in adenocarcinoma patients.

• Analytical Science and Technology
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• v.15 no.6
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• pp.529-533
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• 2002

The separation and determination method of racemic isomers of flurbiprofen in urine samples have been investigated using column switching- HPLC, which include the sample treatment and concentration column. The optical rotation of two isomers separated were measured to identify d-form and l-form. The calibration curves are liear in the ranges of $0.11-5.4{\mu}g/mL$ for both d-form and l-form. The detection limits were $0.031{\mu}g/mL$ for l-isomes and $0.027{\mu}g/mL$ for d-isomer. The coefficients of variation of intra-day and inter-day precision of this method were about 1.8%. The present method was apllied to determine the concentration of racemic isomers in urine sample from human eating the drug.

• Safety and Health at Work
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• v.9 no.4
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• pp.416-420
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• 2018

Background: Urinary 1-hydroxypyrene (1-OHP) has been widely used as a biomarker of polycyclic aromatic hydrocarbons (PAHs) in occupationally exposed workers. The objective of this study is to investigate the concentration of urinary 1-OHP among charcoal workers as subjects and non-charcoal workers as controls. Methods: Early morning urine samples were collected from 68 persons (25 charcoal workers in Igbo-Ora, 20 charcoal workers in Alabata, and 23 non-charcoal workers) who volunteered to participate in this study. 1-OHP determination in urine samples was carried out using high performance liquid chromatography after hydrolysis. Descriptive and inferential statistics were used for data analysis at p < 0.05. Results: The mean urinary 1-OHP concentration (${\mu}mol/mol$ creatinine) among charcoal workers at Igbo-Ora and Alabata and non-charcoal workers were $2.22{\pm}1.27$, $1.32{\pm}0.65$, and $0.32{\pm}0.26$ (p < 0.01). There existed a relationship between respondent type and 1-OHP concentration. Charcoal workers were 3.14 times more at risk of having 1-OHP concentrations that exceed the American Conference of Governmental Industrial Hygienists guideline of $0.49{\mu}mol/mol$ creatinine than non-charcoal workers (relative risk = 3.14, 95% confidence interval: 1.7-5.8, p < 0.01). Conclusion: Charcoal workers are exposed to PAHs during charcoal production and are at risk of experiencing deleterious effects of PAH exposure. Routine air quality assessment should be carried out in communities where charcoal production takes place. Assessment of urinary 1-OHP concentration and use of personal protective equipment should also be encouraged among charcoal workers.

• Nutrition Research and Practice
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• v.16 no.3
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• pp.366-378
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• 2022

BACKGROUND/OBJECTIVES: The purpose of this study was to develop a sodium index, which is a tool for estimating and assessing sodium intake easily and quickly, to assist in the prevention of various diseases induced by excess sodium intake in Korean adults. SUBJECTS/METHODS: The 24-h urine collection and dietary behavior surveys were performed on 640 healthy people in 4 regions of South Korea, and an equation for the estimation of 24-h sodium intake was developed. The validity and reliability of the equation were verified with 200 adults. The sodium index was developed by converting the estimated sodium intake using the equation. Finally, the sodium intake status of 1,600 adults was assessed using the sodium index. RESULTS: The equation included sex, age, body mass index, eating habit and dietary behaviors related to sodium intake. In validity test of the equation, the mean bias between sodium intake using 24-h urine analysis and using the equation from the Bland-Altman plots was -1.5 mg/day. The sensitivity and specificity of the equation for estimation of sodium intake were 80.5% and 64.4%, respectively. In the reliability test of the equation, there was no significant difference between the first and second sodium intakes calculated using the equations, and Spearman's correlation coefficient between the 2 sodium intakes was 0.98. Sodium intake can be assessed as 'very moderate' for 75-100 on the sodium index, 'moderate' for 100-150, 'careful' for less than 75 or 150-200, and 'severe' for 250 or more. When sodium intake was assessed using the sodium index in 1,600 subjects, 54.3% and 24.3% of the subjects were assessed to be in the 'careful' and 'severe' categories, respectively. CONCLUSIONS: Using a simple questionnaire, the sodium index can be used to monitor and assess sodium intake status, assisting in nutrition education and counseling in a large population.

• Journal of Korean Academy of Nursing
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• v.53 no.4
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• pp.371-384
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• 2023

Purpose: With an increase in the aging population, the number of patients with degenerative spinal diseases undergoing surgery has risen, as has the incidence of postoperative delirium. This study aimed to investigate the risk factors affecting postoperative delirium in older adults who had undergone spine surgery and to identify the associated biomarkers. Methods: This study is a prospective study. Data of 100 patients aged ≥ 70 years who underwent spinal surgery were analyzed. Demographic data, medical history, clinical characteristics, cognitive function, depression symptoms, functional status, frailty, and nutritional status were investigated to identify the risk factors for delirium. The Confusion Assessment Method, Delirium Rating Scale-R-98, and Nursing Delirium Scale were also used for diagnosing delirium. To discover the biomarkers, urine extracellular vesicles (EVs) were analyzed for tau, ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), neurofilament light, and glial fibrillary acidic protein using digital immunoassay technology. Results: Nine patients were excluded, and data obtained from the remaining 91 were analyzed. Among them, 18 (19.8%) developed delirium. Differences were observed between participants with and without delirium in the contexts of a history of mental disorder and use of benzodiazepines (p = .005 and p = .026, respectively). Tau and UCH-L1-concentrations of urine EVs-were comparatively higher in participants with severe delirium than that in participants without delirium (p = .002 and p = .001, respectively). Conclusion: These findings can assist clinicians in accurately identifying the risk factors before surgery, classifying high-risk patients, and predicting and detecting delirium in older patients. Moreover, urine EV analysis revealed that postoperative delirium following spinal surgery is most likely associated with brain damage.

• Korean Journal of Community Nutrition
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• v.12 no.5
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• pp.545-558
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• 2007

This study was performed to assess the sodium intakes of Korean adults using a 24-hr urine analysis and dish frequency questionnaire (DFQ) according to each dish group and the regional area. The subjects of this study were comprised of 522 adults (male : 267, female : 285), aged 20-59yr residing in the metropolitan area (N=200), Chungcheng-Do (N=117), Jeolla-Do(N=117), and Gueongsang-Do provinces (N=118). The subjects were recruited from the residents who once participated or are participating in the various health programs offered by the public health center. The number of subjects who completed the 24-hr urine collection was 205 (male : 110, female : 95). The mean age and BMI of the subjects were $39.0{\pm}$11.7y and $23.1{\pm}2.9 kg/m^2$, respectively. The mean systolic and diastolic blood pressure was $119.5{\pm}15.4 mmHg$, and $77.1{\pm}11.1 mmHg$, respectively. Eighteen percent of the subjects responded that they are currently smoking, 36% drinking and 50.4% exercising. Twenty point six percent of the subjects were assessed as having hypertension according to their systolic or diastolic blood pressure($SBP{\ge}140mmHg$ or $DBP{\ge}90mmHg$) measurements in the present study. Salt intake of the subjects estimated with 24-hr sodium excretion was 12.7g/d (male : 13.4g/d, female : 12.1g/d) based on the sodium excretion rate as 82%. Salt intake estimated with DFQ was 14.7g/d (male : 16.2g/d, female : 13.4g/d), 2 g more than the salt intake estimated with 24-hr urine analysis. The four dish groups that contributed most to the sodium intake in order were kimchi (11571.4mg), soup and stew (1260.5mg), fish and shellfish(706.3mg) and noodle and ramyeon(644.3mg). Salt intake estimated with DFQ was the highest in the subjects of Gueongsang-Do(17.0g/d), second highest Chungcheong-Do (16.4g/d) and the lowest in the metropolitan area (13.0g/d). Subjects of Gueongsang-Do showed the highest sodium intakes in most of the dish group, whereas subjects of the metropolitan area showed the lowest. Residents of Chungcheong-Do revealed the highest sodium intake with kimchi and of Jeolla-Do the higher sodium intake with main dish (meat, fish and beans). The highest salt percentage of kimchi ($3.0{\pm}0.8%$) and soybean paste ($14.5{\pm}5.1%$) were observed in Gueongsang-Do, whereas individuals of the metropolitan area were observed as having kimchi ($1.6{\pm}0.5%$) and soybean paste ($7.4{\pm}1.6%$) with the lowest salt percenage. Men were observed as having more salty kimchi ($2.4{\pm}0.1%$) than women ($2.1{\pm}0.1%$).

• Clinical and Experimental Pediatrics
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• v.46 no.2
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• pp.173-177
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• 2003

Purpose : Recently, different results about factors affecting accurate quantitation of 24-hr urinary protein(24UP) amount using spot urine protein/creatinine ratio(PCR) have been reported. The current study was designed to evaluate correlation between 24UP amounts and PCR in children, and the effect of 24UP amounts, age, sex, and glomerular filtration rate(GFR) on this correlation. Methods : Among 94 patients who visited the department of pediatrics in Busan Paik Hospital from March 2002 to August 2002, 68 patients whose urinary creatinine excretion was ${\geq}15mg/kg/day$ were included in this study. All the patients were divided into I, II/A, B group(I : 24UP<500 mg/day, II : $24UP{\geq}500mg/day$, A : <10 years of age, B : ${\geq}10years$ of age). Pearson correlation analysis was performed between 24UP and PCR to evaluate the relationship. We defined fractional difference between 24UP and PCR, and then performed multiple regression analysis with 24UP amount, age, GFR and fractional difference. Results : There was a strong positive linear correlation between 24UP and PCR(R=0.936, P<0.0001) in all patients, and the correlation was also good in each group. Using PCR cutoff values of 0.5, the PCR provided high sensitivity, specificity, positive and negative predictive value in predicting 24UP amount ${\geq}500mg$. The factors affecting accurate quantitation of proteinuria using spot urine PCR was age, not 24UP amount, GFR or sex. Conclusion : Spot urine PCR is a useful test but has limitations in predicting 24UP amount. Therefore, it should be used only as screening method. Age-adjusted PCR cutoff values may be necessary to predict 24UP amount in children with proteinuria.

• Analytical Science and Technology
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• v.9 no.4
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• pp.336-344
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• 1996

The extraction of trace cobalt, copper, nickel, cadmium, lead and zinc in urine samples of organic and alkali metal matrix into chloroform by the complex with a dithizone was studied for graphite furnace AAS determination. Various experimental conditions such as the pretreatment of urine, the pH of sample solution, and dithizone concentration in a solvent were optimized for the effective extraction, and some essential conditions were also studied for the back-extraction and digestion as well. All organic materials in 100 mL urine were destructed by the digestion with conc. $HNO_3$ 30 mL and 30% $H_2O_2$ 50 mL. Here, $H_2O_2$ was added dropwise with each 5.0 mL, serially. Analytes were extracted into 15.0 mL chloroform of 0.1% dithizone from the digested urine at pH 8.0 by shaking for 90 minutes. The pH was adjusted with a commercial buffer solution. Among analytes, cadmium, lead and zinc were back-extracted to 10.00 mL of 0.2 M $HNO_3$ from the solvent for the determination, and after the organic solvent was evaporated, others were dissolved with $HNO_3-H_2O_2$ and diluted to 10.00 mL with a deionized water. Synthetic digested urines were used to obtain optimum conditions and to plot calibration-eurves. Average recoveries of 77 to 109% for each element were obtained in sample solutions in which given amounts of analytes were added, and detection limits were Cd 0.09, Pb 0.59, Zn 0.18, Co 0.24, Cu 1.3 and Ni 1.7 ng/mL, respectively. It was concluded that this method could be applied for the determination of heavy elements in urine samples without any interferences of organic materials and major alkaline elements.

• Journal of environmental and Sanitary engineering
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• v.6 no.2
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• pp.109-121
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• 1991

For the analysis of mercury in blood and urine, many literatures have been reffered and many kinds of reducing agents for mercury reduction and many acids for pretreatmr are known to be varied. $So HNO_{3}$ and $H_{2}SO_{4}$ among acids and $SnCl_{2}$ and $NaBH_{4}$ as a reducing agent being chosen for the establishment of more efficient and less erroneous analysis, and comparing the absorbance by using vapor generator, the results are followings. 1. The difference of absorbance from concentration of $HNO_{3}$ and $H_{2} SO_{4}$ was not nearly found when mercury reduced by $NaBH_{4}$ after pretreatment. But for more precise analysis, conc acid treatment need to be used. 2. Higher absorbance was shown by using conto acid treatment (P<0.005) when mercury reduced by $NaBH_{4}$ after treating acid primer. And sample which has 99.5% reliability in T-test, treated by conc $H_{2}SO_{4}$(P<0.005) was shown higher absorbance than treat by CORC $HNO_{3}$. 3. The difference of absorbance was not in the slightest in higher 0.1 w/v% $NaBH_{4}$ proved by uruskal-wallis H-Test 4. Some difference of absorbance in $SnCl_{2}$(P<0.005) having 99.5% reliability was found but there was no difference in these 20 w/v% , 25 w/v% and 30 w/v% SnCl$_{2}$ by the experiment of T-test. 5. According to these test results, organic materials were much affect the absorballce when reducing mercury by using $SnCl_{2}$ rather than by $NaBH_{4}$. For bio sample which is contained various organic substances, reduclng agent $NaBH_{4}$ is a lot more efficient to reduce the error then $SnCl_{2}$. 6. analytic method for this study is as following. 7. As the recovery test was done by this, the rate of recovery was shown form 94% to 100.7% .

• YAKHAK HOEJI
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• v.52 no.6
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• pp.452-465
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• 2008

Hair analysis for drugs of abuse offers the crucial potential advantage when compared to urine, such as the longer time window of drug intake, which makes retrospective investigation of chronic and/or past consumption. This paper reviews the physiological basis of hair growth, mechanism of drug incorporation, analytical methods, result interpretation and practical application of hair analysis. Moreover, to facilitate the court's decision regarding specific circumstances surrounding the crime, this review demonstrated that the results of hair analysis not only should be admitted as scientific evidence of drug use but also could legally improve reliability of the evidence.