• Annals of Laboratory Medicine
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• v.38 no.6
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• pp.503-511
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• 2018

Background: Sampling a healthy reference population to generate reference intervals (RIs) for complete blood count (CBC) parameters is not common for pediatric and geriatric ages. We established age- and sex-specific RIs for CBC parameters across pediatric, adult, and geriatric ages using secondary data, evaluating patterns of changes in CBC parameters. Methods: The reference population comprised 804,623 health examinees (66,611 aged 3-17 years; 564,280 aged 18-59 years; 173,732 aged 60-99 years), and, we excluded 22,766 examinees after outlier testing. The CBC parameters (red blood cell [RBC], white blood cell [WBC], and platelet parameters) from 781,857 examinees were studied. We determined statistically significant partitions of age and sex, and calculated RIs according to the CLSI C28-A3 guidelines. Results: RBC parameters increased with age until adulthood and decreased with age in males, but increased before puberty and then decreased with age in females. WBC and platelet counts were the highest in early childhood and decreased with age. Sex differences in each age group were noted: WBC count was higher in males than in females during adulthood, but platelet count was higher in females than in males from puberty onwards (P <0.001). Neutrophil count was the lowest in early childhood and increased with age. Lymphocyte count decreased with age after peaking in early childhood. Eosinophil count was the highest in childhood and higher in males than in females. Monocyte count was higher in males than in females (P <0.001). Conclusions: We provide comprehensive age- and sex-specific RIs for CBC parameters, which show dynamic changes with both age and sex.

• Annals of Clinical Neurophysiology
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• v.21 no.2
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• pp.87-93
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• 2019

Background: The standardized autonomic function test has become widely available. However, there are no reference data for this test for the Korean population. This study explored reference data for sudomotor and cardiovagal function tests for the Korean population. Methods: The sweat volume by quantitative sudomotor axon reflex test, heart-rate response to deep breathing (HRdb), expiration:inspiration (E:I) ratio, and Valsalva ratio (VR) were measured in 297 healthy Korean volunteers aged from 20 to 69 years. Multivariate regression analysis was performed to evaluate the effects of age, sex, and body mass index on these variables. The 2.5th, 5th, 10th, 90th, 95th, and 97.5th percentile values were obtained for each investigation. Results: The sweat volume was higher in males than in females. The HRdb and E:I ratio were negatively correlated with age, and were higher in males than in females. The VR was negatively correlated with age, but it was not correlated with sex. Conclusions: This study has provided data on the reference ranges for sudomotor and cardiovagal function tests in healthy Korean adults.

• Endocrinology and Metabolism
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• v.33 no.4
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• pp.466-472
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• 2018

Background: Thyroid dysfunction is associated with negative neonatal and obstetric outcomes. Large differences in thyroid function reference intervals exist across different populations. These differences can be explained by population-specific factors, such as iodine status. Many countries in Latin America report iodine sufficiency, but relatively few countries have published up-to-date data on iodine levels and thyroid function in the overall population, and especially in pregnant women. We evaluated the iodine status of pregnant women in Chile and determined thyroid hormone reference ranges in this population. Methods: This was a prospective observational study of healthy Chilean women at their first prenatal visit before week 14. Thyroid-stimulating hormone (TSH), total thyroxine ($T_4$), free $T_4$, antithyroid peroxidase antibody (TPOAb), and iodine levels from spot urine samples were measured. Iodine status and the reference ranges for TSH were calculated. Results: A total of 1,022 pregnant women in the first trimester were selected. Urinary iodine levels were measured in 302 randomly-selected women. The median urinary iodine concentration was $173.45{\mu}g/L$ (interquartile range, 108.11 to 249.35).The reference ranges of TSH were calculated in 670 patients selected according to the National Academy of Clinical Biochemistry guidelines. The median TSH level was $1.88{\mu}IU/mL$ (2.5th percentile: 0.13 to 97.5th percentile: 5.37). Using the reference range in the 1,022 women, the prevalence of clinical hypothyroidism was 1.76%, and that of subclinical hypothyroidism was 3.92%. TPOAb positivity was more common in women with TSH levels above $3.5{\mu}IU/mL$. Conclusion: We found adequate iodine intake and a right-shifted distribution of serum TSH levels in pregnant women in Chile. The prevalence of hypothyroidism in our sample of pregnant women was higher than has been described in the literature.

• Journal of Radiation Protection and Research
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• v.46 no.4
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• pp.170-177
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• 2021

Background: The International Commission on Radiological Protection is preparing to provide reference dose coefficients for environmental radioiodine intake based on newly developed age-specific biokinetic models. However, the biokinetics of iodine has been reported to be strongly dependent on the dietary intake of stable iodine; for example, the thyroidal uptake of iodine may be substantially lower in iodine-rich regions than in iodine-deficient regions. Therefore, this study attempted to establish a system of age-specific thyroid dose estimation for South Koreans, whose daily iodine intakes are significantly higher than that of the world population. Materials and Methods: Korean age-specific biokinetic parameters and thyroid masses were derived based on the previously developed Korean adult model and the Korean anatomical reference data for adults, respectively. This study complied with the principles used in the development of age-specific biokinetic models for world population and used the ratios of baseline values for each age group relative to the value for adults to derive age-specific values. Results and Discussion: Biokinetic model predictions based on the Korean age-specific parameters showed significant differences in iodine behaviors in the body compared to those predicted using the model for the world population. In particular, the Korean age-specific thyroid dose coefficients for ¹²⁹I and ¹³¹I were considerably lower than those calculated for the world population (25%-76% of the values for the world population). Conclusion: These differences stress the need for Korean-specific internal dose assessments for infants and children, which can be achieved by using the data calculated in this study.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.4
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• pp.268-274
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• 2023

Background: Recently, the single-step genomic best linear unbiased prediction (ssGBLUP) method, which incorporates not only genomic information but also phenotypic information of pedigree, is under study. In this study, we performed a ssGBLUP analysis on a commercial Hanwoo population using phenotypic, genotypic, and pedigree data. Methods: The test population comprised Hanwoo 1,740 heads raised in four regions of Korea, while the reference population used Hanwoo 18,499 heads raised across the country and two-generation pedigree data. Analysis was performed using genotype data generated by the Hanwoo 50 K SNP beadchip. Results: The mean Genome estimated breeding values (GEBVs) estimated using the ssGBLUP methods for carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS) were 7.348, 1.515, -0.355, and 0.040, respectively, while the accuracy of each trait was 0.749, 0.733, 0.769, and 0.768, respectively. When the correlation analysis between the GEBVs as a result of this study and the actual slaughter performance was confirmed, CWT, EMA, BFT, and MS were reported to be 0.519, 0.435, 0.444, and 0.543, respectively. Conclusions: Our results suggest that the ssGBLUP method enables a more accurate evaluation because it conducts a genetic evaluation of an individual using not only genotype information but also phenotypic information of the pedigree. Individual evaluation using the ssGBLUP method is considered effective for enhancing the genetic ability of farms and enabling accurate and rapid improvements. It is considered that if more pedigree information of reference population is collected for analysis, genetic ability can be evaluated more accurately.

• IMMUNE NETWORK
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• v.14 no.6
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• pp.289-295
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• 2014

Flow cytometric immunophenotyping of peripheral blood lymphocyte subsets is a powerful tool for evaluating cellular immunity and monitoring immune-mediated diseases. The numbers and proportions of blood lymphocyte subsets are influenced by factors such as gender, age, ethnicity, and lifestyle. This study aimed to establish reference ranges for peripheral blood lymphocyte subsets in a healthy Korean population. Blood samples from 294 healthy adults were collected. Lymphocyte subsets were analyzed using a single-platform method with a flow cytometer; white blood cells and lymphocytes were analyzed using an automated hematology analyzer. The mean value of the white blood cell count was $5,665cells/{\mu}l$, and the mean values of the subtype counts (percentages) were as follows: lymphocytes, $1,928cells/{\mu}l$ (35.08%); $CD3^+$ cells, $1,305cells/{\mu}l$ (67.53%); $CD3^+CD4^+$ cells, $787cells/{\mu}l$ (40.55%); $CD3^+CD8^+$ cells, $479cells/{\mu}l$ (25.23%); $CD3^-CD19^+$ cells, $203cells/{\mu}l$ (10.43%); and $CD3^-CD56^+$ cells, $300cells/{\mu}l$ (15.63%). Additionally, the $CD4^+/CD8^+$ ratio was 1.81. In this study, gender and age significantly influenced blood lymphocyte subsets. Our results demonstrate that, as with other populations, a healthy Korean population has its own, region-specific, lymphocyte subset reference ranges.

• The Journal of the Korean life insurance medical association
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• v.30 no.2
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• pp.20-27
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• 2011

Lung diseases are common in general population and they are also important in insurance medicine. According to current textbook of insurance medicine, there are references of western research which performed at 1980s and early 2000. It's necessary to update the reference. In this article, several respiratory disorders such as Kartagener's syndrome, bronchial asthma, drug-resistant tuberculosis, etc are reviewed in terms of insurance medicine. Reference articles were used in Korean study, if possible. I hope this article being a role of helping many insurance doctors and underwriters in Korea.

• Journal of the Korean Data and Information Science Society
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• v.16 no.3
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• pp.539-547
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• 2005

We propose the Bayesian testing for the equality of two independent Inverse Gaussian population means using the fractional Bayesian factors suggested by O' Hagan(1995). As prior distribution for the parameters, we assumed the noninformative priors. In order to investigate the usefulness of the proposed Bayesian testing procedures, the behaviors of the proposed results are examined via real data analysis.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2605-2610
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• 2016

The International Myeloma Working Group considers the serum free light chain (SFLC) assay to be an adjunct to traditional tests. Apart from the FLC ratio, the absolute values of individual free light chains also are gaining importance as they appear to be more relevant in certain clinical settings. Automated assays are available for their determination. As laboratories put new test systems into use catering to different disease populations, they are required by accreditation and certification bodies to verify or establish performance specifications, including reference intervals (RIs) representative of their population. Our aim was to establish local RIs for SFLC in a multicentre representative healthy population using a robust method. There was no significant relationship between SFLC levels and age, gender and creatinine levels. The 95% RI for ${\kappa}SFLC$ was 4.81 to 33.86mg/L, for ${\lambda}$ SFLC was 5.19 to 23.67mg/L and for ${\kappa}/{\lambda}SFLC$ was 0.36 to 2.33, significantly higher than the values given by the manufacturer. The ${\kappa}/{\lambda}$ SFLC ratio at 2.23, covering 100% of the data, showed 72% sensitivity (95% CI=39.0 - 94.0), 100% specificity (95% CI=71.5 - 100.0), 100% PPV (95% CI=21.5 - 100.0), 95% NPV (95% CI=75.4 - 99.9), and 79% accuracy (95% CI=56.0 - 93.0). In the patient group, kit RI for ${\kappa}/{\lambda}$ SFLC ratio classified 45.5% (n=5) as positive vs 9.1% (n=1) positive by the study RI, while the kit RI for kappa FLC classified 90.9% (n=10) as positive vs 54.5% (n=6), indicating increased probability of false positive test results with the kit RI when applied to our patient population. Appropriate and specific reference intervals and criteria values result in fewer false-positive and false-negative results which means fewer wrong or missed diagnoses.

• Journal of Nutrition and Health
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• v.42 no.2
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• pp.183-188
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• 2009

There has been a need to update the current Codex nutrient reference values (NRVs) which had been established following the Helsinki Consultation in 1988. The main purposes of NRVs are to help consumers compare the nutrient content of different food products and estimate the usefulness of a food product in terms of its percentage contribution to the overall healthful diets. The establishment of Codex NRVs for labelling purposes is intended to facilitate the goals of protecting consumers' health and ensuring fair practices in food trade. When revising the Codex NRVs several issues are needed to discussed, which are: 1) Consideration of population groups whether to have one set of NRVs for general population or to have several sets of NRVs for each population groups, 2) Determination of scope of nutrients such as what nutrients to include and what reference values to choose and 3) Development of principles for establishing NRVs such as the selection of suitable reference values among many including recommended intake/recommended dietary allowances, estimated average requirement and upper levels to extract NRVs. This paper will discuss the above issues and the inputs and efforts that the Korean Nutrition Society had put into to carry out the project, "International Collaboration on the Revision and Addition of the Codex Nutrient Reference Values for Food Labelling Purposes," and to ascertain relevant scientific principles and evidences that are utilized for establishment and revision of the Codex NRVs.