• 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.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.147-151
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• 2006

Although various automated CBC analyzers with different WBC analytical principles were consequently introduced to clinical laboratory, the specific information concerning the suitability or unsuitability of aging samples is scarce. For this reason, we studied the effect of storage duration and temperature on CBC parameter in SE-9000 (SYSMEX Medical Electronics Co., Ltd., Kobe, Japan), automated CBC analyzer. We tested 32 K3-EDTA specimens with SE-9000 during 72 hours. Specimens were kept at room temperature (RT) and refrigerated and were analyzed at 0 hr, 4 hr, 8 hr, 24 hr, 48 hr and 72 hr after the collection of the specimens. The percentage changes from initial value for each parameters were calculated. Among the CBC parameters, hemoglobin, red blood cell count, mean corpuscular hemoglobin and platelets were stable for the study period at both temperatures. The mean corpuscular volume (MCV), hematocrit (Hct) and red cell distribution (RDW) increased and the mean corpuscular hemoglobin concentration (MCHC) decreased over time at room temperature. These parameters were stable when refrigerated. The leukocyte count was stable during 72hr at RT and when refrigerated. At room temperature, the relative percentages of neutrophils tend to increase, whereas those of lymphocyte and monocytes tend to decrease after 48 hours. When refrigerated, those of neutrophils and monocytes tend to increase, whereas those of lymphocytes tend to decreased over time. CBC parameters of refrigerated specimen were reliable for 72 hr for the exception of differential count from 24 hr but many CBC parameters, such as MCV, Hct, MCHC, RDW and differential count of leukocyte of blood stored at room temperature for 24 hr were unreliable.

• Journal of the Korean Applied Science and Technology
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• v.39 no.1
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• pp.52-62
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• 2022

The purpose of this study was to find a way to improve the stability and quality of urinalysis by checking the changes in the measurement values of representative clinical chemistry test items according to the repeated freezing and thawing before the urine test and the thawing process. All subjects were 10 healthy males, and the freeze and thaw stability test was performed using their urine samples. In the case of micro-albumin and amylase, there was no statistical significance at 37℃ with time, but at 42℃ and 60℃, there was a statistically significant change in the results with time. There were statistically significant changes in BUN, creatinine, uric acid, and glucose. As a result of long-term stability, after 7 days, glucose mutation increased and amylase decreased at 60℃. In the case of glucose and amylase, there was a statistically significant change in the results over time. To obtain accurate test results, accurate standardization of urinalysis including appropriate collection, storage, and storage methods of urine samples is required and systematic study of conditions for securing stability for each biomaterial is required.

• Advances in environmental research
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• v.2 no.1
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• pp.9-17
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• 2013

Urine is a widely used matrix in biomonitoring studies on the assessment of human exposure to environmental chemicals such as phthalate esters and bisphenol A (BPA). In addition to the need to apply valid analytical techniques, assurance of specimen integrity during collection and storage is an important prerequisite for the presentation of accurate and precise analytical data. One of the common issues encountered in the analysis of non-persistent contaminants is whether shipping and storage temperature and time since collection have an effect on sample integrity. In this study, we investigated the stability of phthalate metabolites and BPA in spiked and unspiked urine samples stored at room temperature ($20^{\circ}C$) or at $-80^{\circ}C$ for up to 8 weeks. Concentrations of phthalate metabolites declined, on average, by 3% to 15%, depending on the compounds, and BPA declined by ~30% after 4 weeks of storage of spiked urine samples at $20^{\circ}C$. In a test of 30 unspiked urine samples stored at $20^{\circ}C$ and at $-80^{\circ}C$ for 8 weeks, the concentrations of phthalate metabolites and BPA decreased by up to 15% to 44%, depending on the compound and on the samples. It was found that the small reduction in phthalate concentrations observed in urine, varied depending on the samples. In a few urine samples, concentrations of phthalate metabolites and BPA did not decline even after storage at $20^{\circ}C$ for 8 weeks. We found a significant relationship between concentrations of target analytes in urine stored at $20^{\circ}C$ and at $-80^{\circ}C$ for 8 weeks. We estimated the half-lives of phthalate metabolites and BPA in urine stored at $20^{\circ}C$. The estimated half-life of monoethyl phthalate (mEP) and mono (2-ethyl-5-carboxyphentyl) phthalate (mECPP) in urine stored at $20^{\circ}C$ was over two years, of mono (2-ethyl-5-oxohexyl) phthalate (mEOHP) and monobenzyl phthalate (mBzP) was approximately one year, and of other phthalate metabolites was approximately 6 months. The estimated half-life of BPA in urine stored at $20^{\circ}C$ was approximately 3 months, which is much longer than that reported for aquatic ecosystems.

• YAKHAK HOEJI
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• v.54 no.4
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• pp.226-231
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• 2010

Oral fluid has become increasingly popular as an alternative specimen in the field of driving under the influence of drugs (DUID) and work place drug testing. In this study, an analytical method for the detection and quantification of ${\Delta}^9$-tetrahydrocannabinol (THC) and its metabolite, 11-nor-9-carboxy-${\Delta}^9$-tetrahydrocannabinol (THC-COOH) in oral fluid by SPE and GC-MS was established and fully validated. The stability of THC and THC-COOH in oral fluid during storage was also determined by examining the THC and THC-COOH concentration changes depending on time and container materials. Oral fluid samples were kept over 21 days at room temperature, $-4^{\circ}C$ and $-20^{\circ}C$ in two different specimen collection tubes; glass and polypropylene tubes. Three replicates for each condition with different temperature and types of a container were analyzed at five different time points over 21 days. When oral fluid samples were stored in glass tubes, the loss of both THC and THC-COOH was less than 10% at all room temperature, $-4^{\circ}C$ and $-20^{\circ}C$. However, in polypropylene tubes, the loss of both THC and THC-COOH increased significantly over the study period. In particular, the concentration of THC decreased more rapidly than that of THC-COOH at room temperature and the maximal percentage of THC lost was 90.3% after 21 days. The result indicates that it would be necessary to collect oral fluid samples in glass containers and cool the samples until analysis in order to prevent the degradation of analytes.

• Journal of Pharmaceutical Investigation
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• v.34 no.3
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• pp.161-168
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• 2004

5-Fluorouracil (5-FU) is an antimetabolite anticancer agent active against many types of solid tumors. Tegafur (TF), a prodrug of 5-FU, is frequently used in combination with uracil as dihydropyrimidine dehydrogenase (DPD) inhibitory fluoropyrimidine. We studied the stability of 5-FU and TF in biological fluids of rats and determined their bioavailability (BA) and excretion into bile, and urine. The drug concentrations were analyzed by an HPLC method. At room temperature, there was a 14-30% decrease in the concentration of 5-FU and TF in bile, urine, and plasma specimen at 10 and $100\;{\mu}g/ml$ over 240 min. No significant difference was noted among the sample types or between two different concentrations of 10 and $100{\mu}g/ml$. The decrease in drug concentration was significantly less in samples kept on ice (6-12%) for both drugs. These data indicate that biological fluid samples containing 5-FU or TF in plasma, urine, or bile should be placed on ice during the sample collection. Following these storage guidelines, samples were collected after administration 50 mg/kg of each drug via i.v. or oral route. BA was 1.5 folds greater for TF (60%) than that of 5-FU (42%). Approximately 0.52 and 3.3% of the i.v. doses of 5-FU and TF was excreted into bile, respectively. Renal clearance of 5-FU was about 16% of its total body clearance. These results suggest that instability of 5-FU and TF in biological fluids should be considered in pharmacokinetic or pharmacogenomic studies.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.1
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• pp.1-12
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• 2023

Function of salivary gland and saliva composition can be an indicator of individual's health status. Recently, saliva has been thought to have a high potential for usage in the biomedical field to diagnose, evaluate, and prevent systemic health due to the technological advances in analyzing and detecting small elements such as immunological and metabolic products, viruses, microorganisms, hormones in saliva. As a diagnostic specimen, saliva has some useful advantages compared to serum. Because of simple non-invasive method, saliva sampling is quite comfort for the patient, and it doesn't require specialists to collect samples. The possibility of infection during the collection process is also low. For this reason, proteins, genetic materials, and various biomarkers in saliva are actively being utilized on studying stress, microbiomics, genetics, and epigenetics. For the research on collecting big data related to systemic health, the needs on biobank has been focused. Regeneration of salivary gland based on tissue engineering has been also on advancement. However, there are still many issues to be solved, such as the standardization of sample collection, storage, and usage. This review focuses on the recent trends in the field of saliva research and highlight the future perspectives in biomedical and other applications.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.117-120
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• 2011

Purpose: There are 3 warnings for Glucagon tests. First, EDTA tubes that already contain Aprotinin must be used for plasma collection. Second, for freezer storage of centrifuged plasma, glass tubes must be used. Last, glass tubes must be used for testing procedure. So we compared the glucagon results of next 3 situation to those of control group. First, We compared to results by tubes without Aprotinin and with aprotinin. Second, we compared to results by tubes(plastic vs glass) for plasma storage. Third, we compared to results by tubes(plastic vs glass) for testing. We tried to evaluate the results of the 3 different condition. Materials and Methods: 40 healthy adults were studied with normal results on the general medical check up and laboratory tests. We compared the results of 3 different condition belows: Blood were collected in EDTA tube containing aprotinin and plasma was stored in the glass tube for 3 days in a freezer and results were obtained by tests in the glass tubes. Results from EDTA plasma without aprotinin, results from platic tubes for freezer stroage, results from plastic tube when testing. Simple linear regression analysis and paired t-test using SPSS were done for statistical analysis. Commercial glucagon kit(RIA-method)which made by Siemens company were used. Results: Correlation coefficient between results of EDTA tubes with Aprotinin vs without Aprotinin was r=0.783 (p=0.064). Result of specimen in plastic tubes stored 3 days in a freezer showed lower value compared to those in glass tube(r=0.979, p=0.005). Also, results of testing in plastic tubes showed lower values than those testing in glass tubes. (r=0.754, p<0.001). Conclusion: It is recommended for glucagon determination to use EDTA tube with Aprotinin which is a inhibitor of protein breakdown enzyme. Results of plastic tube when storage and testing showed lower value than those of glass tubes, so it is recommended to store and test in glass tubes.