• Korean Journal of Clinical Laboratory Science
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• v.39 no.1
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• pp.7-18
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• 2007

A total of 1,780 isolates of Enterococcus spp. were isolated from 63,133 clinical specimens from Dec 1, 2005 to Nov 1, 2006 in "C" hospital. Isolation frequencies of Enterococcus spp. were 50.9% for E. faecalis, 41.7% for E. faecium, and 7.4% for other Enterococcus spp. containing E. avium, E. gallinarum, E. casseliflavus, E. durans, E. hirae, and E. raffinosus. There were no significant difference between gender, but according to the age group analysis, Enterococcus spp. were more frequently isolated in patients over 50 years old (20.0~24.6%) than those isolated from the patients under the age of 0~49 (1.3~9.4%). In monthly analysis, Enterococcus spp. were the most frequently isolated in April (11.9%), but presented at lowest frequency in February (5.2%). Seasonal analysis did not show a significant difference. Over half of enterococci were isolated from random urine (44.9%) and catherterized urine (15.7%). Frequencies of vancomycin resistant E. faecalis and E. faecium were 0.1% and 31.0%, respectively. Teicoplanin resistant Enterococcus was 13.3% in E. faecalis, 17.6 % in E. faecium. The Enterococcus species showing over 80% susceptibility against antimicrobial agents were E. faecalis, E. durans and E. hirae in vancomycin; E. faecalis, E. gallinarum, E. casseliflavus, E. durans and E. hirae in ampicillin. The antimicrobial agent showing susceptibility against whole group of Enterococcus species was only linezolid (95.9%), and a selection of antimicrobial agent is necessary to do essential performance identification and susceptibility tests.

• Mass Spectrometry Letters
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• v.7 no.3
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• pp.55-63
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• 2016

Growth hormone (GH)-releasing peptides (GHRPs) and GH secretagogues (GHSs) are listed in the World Anti-Doping Agency (WADA) Prohibited List. In the present study, we developed and validated a method for the simultaneous analysis of seven GHRPs (alexamorelin, GHRP-1, -2, -4, -5, -6, and hexarelin) and three GHSs (anamorelin, ibutamoren, and ipamorelin) in human urine. Method validation was performed at minimum required performance levels specified by WADA technical documents (2 ng/mL) for all substances, and the method was validated with regard to selectivity (no interference), linearity (R2 > 0.9986), matrix effects (50.0%-141.2%), recovery (10.4%-100.8%), and intra- (2.8%-16.5%) and inter-day (7.0%-22.6%) precisions. The limits of detection for screening and confirmation were 0.05-0.5 ng/mL and 0.05-1 ng/mL, respectively.

• Journal of Environmental Health Sciences
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• v.45 no.6
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• pp.594-604
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• 2019

Objectives: This study developed and validated an analysis method of urinary metals and metalloids that can be applied inductively with coupled plasma mass spectrometry (ICP-MS). Methods: 0.3 mL of urine was used to analyze 25 metal and metalloid compounds using ICP-MS. The validation of the analytical method included linearity, accuracy, precision, and the calculation of detection limits. In addition, a comparison test was performed with the graphite furnace atomic absorption spectrometry (GF-AAS) method, which is the current standard method, with urine samples of 66 healthy subjects. Results: The linearities (R²) of calibration curves of all 25 compounds were ≥ 0.999. Of the 25 compounds, the intra-day and inter-day accuracy% of 17 and 20 met ≤15%, respectively. In addition, fifteen compounds showed ≤15% recovery% for certificated reference materials. Intraclass correlation coefficients of the comparison between the current methods and new methods in this study were 0.952 (p-value<0.001) and 0.911 (p-value<0.001) for urinary cadmium and mercury, respectively. Conclusion: This study proposes an efficient simultaneous methodology that can analyze multi elements in smaller sample amounts. More reproduction experiments are needed in the future.

• Animal Bioscience
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• v.36 no.6
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• pp.879-890
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• 2023

Objective: This study was conducted to evaluate the use of Megasphaera elsdenii (M. elsdenii) as a probiotic on rumen fermentation, production performance, carcass traits and health of ruminants by integrating data from various related studies using meta-analysis. Methods: A total of 32 studies (consisted of 136 data points) were obtained and integrated into a database. The parameters integrated were fermentation products, rumen microbes, production performance, carcass quality, animal health, blood and urine metabolites. Statistical analysis of the compiled database used a mixed model methodology. Different studies were considered random effects, while M. elsdenii supplementation doses were considered fixed effects. p-values and the Akaike information criterion were employed as model statistics. The model was deemed significant at p<0.05 or had a tendency to be significant when p-value between 0.05<p<0.10. Results: Supplementation with M. elsdenii increased (p<0.05) some proportion of fermented rumen products such as propionate, butyrate, isobutyrate, and valerate, and significantly reduced (p<0.05) lactic acid concentration, acetate proportion, total bacterial population and methane emission. Furthermore, the probiotic supplementation enhanced (p<0.05) livestock production performance, especially in the average daily gain and body condition score. Regarding the carcass quality, hot carcass weight and carcass gain were elevated (p< 0.05) due to the M. elsdenii supplementation. Animal health also showed improvement as indicated by the lower (p<0.05) diarrhoea and bloat incidences as well as the liver abscess. However, M. elsdenii supplementation had negligible effects on blood and urine metabolites of ruminants. Conclusion: Supplementation of M. elsdenii is capable of decreasing ruminal lactic acid concentration, enhancing rumen health, elevating some favourable rumen fermentation products, and in turn, increasing production performance of ruminants.

• Mass Spectrometry Letters
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• v.15 no.2
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• pp.79 -94
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• 2024

Over the past few decades, new psychoactive substances (NPS) have become prevailing. With the widespread emergence of NPS, phenethylamines (PEAs) have become one of the groups abused most which PEAs, along with other stimulants, make up the majority of stimulants. When determining the NPS, the methods for screening and confirmation are crucial which assesses the reliability of testimony. In this study, a set of GC/MS methods employing two derivatizing agents for determining 76 target PEAs in urine was established and further applied for authentic sample analysis. Five PEAs (N,N-DMA, PMMA, 4-CA, amphetamine, and methamphetamine) with contents over their LLOQs were detected in thirteen of the twenty tested samples. In order to compare the result from the GC/MS methods with the previously established LC-MS/MS method, Cohen's kappa coefficient and McNemar's test were applied for statistical analysis. Perfect agreement between GC/MS and LC-MS/MS techniques for determining target PEAs is demonstrated by the Kappa coefficient for each of the five detected targets.

• 대한예방의학회:학술대회논문집
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• 2003.04a
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• pp.30-37
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• 2003

o Cohort study became the major approach to study of chronic diseases such as CVD and cancer o Cohort can be population-based or volunteer-based o Types of be population-be categorized by source population and selection mechanism o More and more cohort studies involve biological specimens, such as blood, urine, toenail, cheek cells, etc. o Multi-center and multi-national collaboration is an effective way to increase sample size. o Current statistical method typically use time-to-event analysis by Cox proportional hazard model.

• Analytical Science and Technology
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• v.31 no.4
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• pp.161-170
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• 2018

The epidemic of disorders associated with synthetic stimulants, such as methamphetamine (MA) and amphetamine (AP), is a health, social, legal, and financial problem. Owing to the high potential of their abuse and addiction, reliable analytical methods are required to detect and identify MA, AP, and their metabolites in biological samples. Thus, a dilute-and-shoot liquid chromatography-tandem mass spectrophotometry (LC-MS/MS) was developed for simultaneous determination of MA, 4-hydroxymethamphetamine (4HMA), AP, and 4-hydroxyamphetamine (4HA) in urine. Urine sample ($100{\mu}L$) was mixed with $50{\mu}L$ of mobile phase consisting of 0.4 % formic acid and methanol and $50{\mu}L$ of working internal-standard solution. Aliquots of $8{\mu}L$ diluted urine was injected into the LC-MS/MS system. For all analytes, chromatographic separation was performed using a C18 reversed-phase column with gradient elution and a total run time of 5 min. The identification and quantification were performed by multiple reaction monitoring (MRM). Linear least-squares regression was conducted to generate a calibration curve, with $1/x^2$ as the weighting factor. The linear ranges were 2.0-200, 1.0-800, and 10-2500 ng/mL for 4HA and 4HMA, AP, and MA, respectively. The inter- and intraday precisions were within 6.6 %, whereas the inter- and intraday accuracies ranged from -14.9 to 11.3 %. The low limits of quantification were 2.0 ng/mL (4HA and 4HMA), 1.0 ng/mL (AP), and 10 ng/mL (MA). The proposed method exhibited satisfactory selectivity, dilution integrity, matrix effect, and stability, which are required for validation. Moreover, the purification efficiency of high-speed centrifugation was clearly higher than 6-15 % for QC samples (n=5), which was higher than that of the membrane-filtration method. The applicability of the proposed method was tested by forensic analysis of urine samples from drug abusers.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.123-131
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• 2009

Purpose: We tested a sample of nuclear medicine workers at Korean healthcare institutions for internal contamination with radioactive isotopes, measuring concentrations and evaluating doses of individual exposure. Materials and Methods: The detection and measurement was performed on urine samples collected from 25 nuclear medicine workers at three large hospitals located in Seoul. Urine samples were collected once a week, 100~200 mL samples were gathered up to 6~10 times weekly. A high-purity germanium detector was used to measure gamma radiations in urine samples for the presence of radioactive isotopes. Based on the detection results, we estimated the amounts of intake and committed effective doses using IMBA software. In cases where committed effective doses could not be adequately evaluated with IMBA software, we estimated individual committed effective doses for radionuclides with a very short half life such as $^{99m}Tc$ and $^{123}I$, using the methods recommended by International Atomic Energy Agency. Results: Radionuclides detected through the analysis of urine samples included $^{99m}Tc$, $^{123}I$, $^{131}I$ and $^{201}Tl$, as well as $^{18}F$, a nuclide used in Positron Emission Tomography examinations. The committed effective doses, calculated based on the radionuclide concentrations in urine samples, ranged from 0 to 5 mSv, but were, in the majority of cases, less than 1 mSv. The committed effective dose exceeded 1 mSv in three of the samples, and all three were workers directly handling radioactive sources. No nurses were found to have a committed effective dose in excess of 1 mSv. Conclusions: To improve the accuracy of results, it may be necessary to conduct a long-term study, performed over a time span wide enough to allow the clear determination of the influence of seasonal factors. A larger sample should also help increase the reliability of results. However, as most Korean nuclear medicine workers are currently not necessary to monitored routinely for internal contamination with radionuclides. Notwithstanding, a continuous effort is recommended to reduce any unnecessary exposure to radioactive substances, even if in inconsequential amounts, by regularly surveying workplace environments and frequently monitoring atmospheric concentrations of radionuclides.

• Journal of Preventive Medicine and Public Health
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• v.36 no.3
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• pp.209-212
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• 2003

Because of advances of technologies in the field of genmic epidemiology in the recent years, specimen collection, storage and analysis became an essential part of research methodologies. DNA is now being used in epidemiologic studies to evaluate genetic risk factors and specimens other than the fresh whole blood can De used for PCR. Therefore, All nucleated cells, such as buccal swabs and urine specimens, are suitable for DNA analysis. For an unlimited source of genomic DNA, EBV transformation of lymphocytes can be used for immortalization. However, the type of specimen collected in genomic epidemiologic studies will depend on the study where the epidemiologist play a leading role for the design. We also briefly described various finds of analysis for SNP that is an essential part of the genomic epidemiology.

• Journal of Korean Physical Therapy Science
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• v.13 no.2
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• pp.67-83
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• 2006

The present study examined that in Vivo/Vitro test is investigated in normotensive sham-operated rats (NSR) and aldosterone-analogue deoxycorticosterone acetate (DOCA)-salt hypertensive rats (ADHR) and that the antihypertensive effect was induced by silver spike point (SSP) electrical stimulation at meridian points(CV-3, -4, Ki-12, SP-6, LR-3, BL-25, -28, -32, -52), specifically, such as aldosterone in 24 hour urine analysis from healthy volunteer. The gross examination and morphometric-histological changes, such as hypertrophy, production of necrotic tissues, and the changes of cell arrangement on the kidney, and adrenal gland were markedly observed in aldosterone-analogue DOCA-salt hypertensive rats compared with those from normotensive sham-operated rats. The systolic blood pressure, weight of kidney and adrenal gland were significantly increased in ADHR than that in NSR. The required time of PSS-induced resting tone was significantly increased in ADHR than that in NSR. However, the voltage-dependent K+ (Kv) currents were significantly decreased in ADHR than that in NSR. The urine analysis showed that the concentration of aldosterone was significantly decreased in resting state from the elderly people compared with those from the adolescent healthy volunteer. The current of 1 Hz continue type of SSP electrical stimulation significantly decreased in the concentration of aldosterone of 24 hour urine from the elderly people. These results suggest that the development of aldosterone analogue-induced hypertension is associated with changed the weight of kidney and adrenal gland, blood pressure, resting tone and Kv currents, which directly affects blood pressure. Therefore, the hypertension is a risk factor on cerebrovascular disease. Moreover, these results suggest that the diminished responsiveness to SSP electrical stimulation, especially current of 1Hz continue type, in elderly people may be, in part, related by the increased of antihypertensive effects.