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At least 19 recordsLinked to original sources
PubMed2024

Genomic prediction and genome-wide association studies of morphological traits and distraction index in Korean Sapsaree dogs.

The Korean Sapsaree dog is a native breed known for its distinctive appearance and historical significance in Korean culture. The accurate estimation of breeding values is essential for the genetic improvement and conservation of such indigenous breeds. This study aimed to evaluate the accuracy of breeding values for body height, body length, chest width, hair length, and distraction index (DI) traits in Korean Sapsaree dogs. Additionally, a genome-wide association study (GWAS) was conducted to identify the genomic regions and nearby candidate genes influencing these traits. Phenotypic data were collected from 378 Korean Sapsaree dogs, and of these, 234 individuals were genotyped using the 170k Illumina CanineHD BeadChip. The accuracy of genomic predictions was evaluated using the traditional BLUP method with phenotypes only on genotyped animals (PBLUP-G), another traditional BLUP method using a pedigree-based relationship matrix (PBLUP) for all individuals, a GBLUP method based on a genomic relationship matrix, and a single-step GBLUP (ssGBLUP) method. Heritability estimates for body height, body length, chest width, hair length, and DI were 0.45, 0.39, 0.32, 0.55, and 0.50, respectively. Accuracy values varied across methods, with ranges of 0.22 to 0.31 for PBLUP-G, 0.30 to 0.57 for PBLUP, 0.31 to 0.54 for GBLUP, and 0.39 to 0.67 for ssGBLUP. Through GWAS, 194 genome-wide significant SNPs associated with studied Sapsaree traits were identified. The selection of the most promising candidate genes was based on gene ontology (GO) terms and functions previously identified to influence traits. Notable genes included CCKAR and DCAF16 for body height, PDZRN3 and CNTN1 for body length, TRIM63, KDELR2, and SUPT3H for chest width, RSPO2, EIF3E, PKHD1L1, TRPS1, and EXT1 for hair length, and DDHD1, BMP4, SEMA3C, and FOXP1 for the DI. These findings suggest that significant QTL, combined with functional candidate genes, can be leveraged to improve the genetic quality of the Sapsaree population. This study provides a foundation for more effective breeding strategies aimed at preserving and enhancing the unique traits of this Korean dog breed.

Animals↗
PubMed2025

Development and evaluation of a machine learning model for osteoporosis risk prediction in Korean women.

BACKGROUND: The aim of this study was to develop a machine learning (ML) model for classifying osteoporosis in Korean women based on a large-scale population cohort study. This study also aimed to assess ML model performance compared with traditional osteoporosis screening tools. Furthermore, this study aimed to examine the factors influencing the risk of osteoporosis through variable importance. METHODS: Data was collected from 4199 women aged 40-69 years in the baseline survey of the Ansan and Ansung cohort of the Korean Genome and Epidemiology Study. Osteoporosis was set as the dependent variable to develop ML classification models. Independent variables included 122 factors related to osteoporosis risk, such as socio-demographic characteristics, anthropometric parameters, lifestyle factors, reproductive factors, nutrient intakes, diet quality indices, medical history, medication history, family history, biochemical parameters, and genetic factors. The six classification models were developed using ML techniques, including decision tree, random forest, multilayer perceptron, support vector machine, light gradient boosting machine, and extreme gradient boosting (XGBoost). The six ML classification models were compared with two traditional osteoporosis screening tools, including the osteoporosis risk assessment instrument (ORAI) and the osteoporosis self-assessment tool (OST). The ML model performances were evaluated and compared using the confusion matrix and area under the curve (AUC) metrics. Variable importance was assessed using the XGBoost technique to investigate osteoporosis risk factors. RESULTS: The XGBoost model showed the highest performance out of the six ML classification models, with an accuracy of 0.705, precision of 0.664, recall of 0.830, and F1 score of 0.738. Moreover, the XGBoost model showed a higher performance on AUC than ORAI and OST. Variable importance scores were identified for 69 out of the 122 variables associated with osteoporosis risk factors. Age at menopause ranked first in variable importance. Variables of arthritis, physical activities, hypertension, education level, income level; alcohol intake, potassium intake, homeostatic model assessment for insulin resistance; energy intake, vitamin C intake, gout; and dietary inflammatory index ranked in the top 20 out of the 69 variables, using the XGBoost technique. CONCLUSIONS: This study found that an XGBoost model can be utilized to classify osteoporosis in Korean women. Age at menopause is a significant factor in osteoporosis risk, followed by arthritis, physical activities, hypertension, and education level.

Humans↗
PubMed2026

ONT-only genome assembly of a Korean male individual using a semen sample.

BACKGROUND: Long-read sequencing has enabled the generation of high-quality human genome assemblies, but many previous assemblies were based on blood-derived DNA and often relied on limited data types from a single sequencing strategy. OBJECTIVE: This study aimed to generate high-quality phased genome assemblies of a Korean individual using multiple independent long-read datasets produced from a single sequencing platform and to evaluate their utility for chromosome-scale assembly and variant detection. METHODS: Genomic DNA was extracted from a semen sample of a Korean male. Long-read, ultra-long-read, and chromatin conformation capture sequencing data were generated using Oxford Nanopore Technologies. These datasets were integrated to construct phased genome assemblies, followed by correction of noticeable phasing errors and assessment of assembly continuity, chromosomal representation, telomeric repeat recovery, and variant detection performance. RESULTS: The final phased assemblies spanned approximately 2.9 Gb and represented 23 pairs of chromosomes with an NG50 of 150 Mb. Telomeric repeats were detected at 36 and 37 of the 48 chromosomal ends in the two assemblies, indicating high end-to-end completeness. In addition, we successfully identified structural variants, including small variants. These results demonstrate that combining multiple Oxford Nanopore data types can produce highly continuous and informative phased human genome assemblies. CONCLUSIONS: We generated high-quality phased genome assemblies of a Korean individual using Oxford Nanopore long-read sequencing data derived from semen DNA. This publicly available genome resource will support broader applications of long-read sequencing in human genomics and variant analysis.

Humans↗
PubMed1975

Follow-up studies of World War II and Korean war prisoners. II. Morbidity, disability, and maladjustments.

US Army veterans taken prisoner (POW's) in World War II and in the Korean War are compared with controls as to hospital admissions from 1946 to 1965 (1954-1965 for Korean War POW's), and as to symptoms, disability, and maladjustments in 1966-1967. Sequelae of the POW experience are both somatic and psychiatric, and are of greatest extent and severity among Pacific World War II POW's. Among European World War II POW's only psychiatric sequelae are apparent. Somatic sequelae were most prevalent in the early years after liberation, but for Pacific World War II POW's they persist in the form of higher hospital admission rates for many specific causes in the most recent period. Nevertheless, persistent psychiatric sequelae (especially psychoneurosis but also schizophrenia) are the more notable and pervasive for both Pacific World War II POW's and Korean War POW's as seen not only in elevated hospital admission rates but also in VA disability awards and in symptoms reported on the cornell Medical Index Health Questionnaire. The excess morbidity appears to correlate well with retrospective accounts of weight-loss and nutritional deficiency diseases and symptoms during the POW period.

Aged↗
PubMed2026

Development and external validation of an explainable machine learning model for predicting chronic kidney disease progression in the Korean population.

BACKGROUND: Current risk stratification models, such as the Kidney Failure Risk Equation (KFRE), exhibit variable performance across ethnic groups and fail to capture dynamic clinical trajectories. This study aimed to develop and validate a Korean-specific machine learning (ML) model for predicting chronic kidney disease (CKD) progression using an ensemble approach. METHODS: We used electronic health records from Seoul National University Hospital for model development (n = 28,209) and the Korean Genome and Epidemiology Study (KoGES) CKD cohort for external validation (n = 3,960). The primary outcome was a composite of ≥40% decline in estimated glomerular filtration rate (eGFR) or progression to end-stage renal disease within 2 years. A soft-voting ensemble of four ML algorithms (XGBoost, LightGBM, CatBoost, and Random Forest) was developed. RESULTS: The ensemble model demonstrated robust discrimination in internal validation (area under the receiver operating characteristic curve [AUROC], 0.939; 95% confidence interval [CI], 0.934-0.944), significantly exceeding the KFRE (AUROC, 0.879-0.884). External validation in the KoGES cohort showed comparable discrimination (AUROC, 0.859; 95% CI, 0.798-0.914) versus KFRE (four-variable AUROC, 0.882; 95% CI, 0.818-0.935). Shapley Additive exPlanations (SHAP) analysis identified baseline eGFR, serum creatinine, eGFR slope, albumin, and hemoglobin as key prognostic features, supporting a complementary framework using KFRE for community screening and the ML model for hospital-based risk stratification. CONCLUSION: The ensemble ML model accurately predicts short-term CKD progression in Korean patients. By incorporating longitudinal features and ensemble learning, it provides a precise alternative to Western-derived equations, particularly in tertiary care settings.

Chronic kidney failure↗
PubMed2026

Dietary Laver Intake and Risk of Incident Abdominal Obesity Among Korean Adults: An 18-Year Prospective Cohort Study.

Background/Objectives: Abdominal obesity is a major risk factor for metabolic disorders, including type 2 diabetes and cardiovascular disease. Laver (Porphyra spp.), a seaweed commonly consumed in Korea, contains dietary fiber and bioactive compounds that may help reduce abdominal fat accumulation. This study aimed to investigate the association between laver intake and the incidence of abdominal obesity in Korean adults. Methods: Data from 5457 adults aged 40-69 years who participated in the Korean Genome and Epidemiology Study were analyzed. Laver intake was assessed at baseline using a validated 103-item food frequency questionnaire. Abdominal obesity was defined as waist circumference of ≥90 cm in men and ≥85 cm in women. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: During 18 years of follow-up, 1202 men (39.4%) and 1117 women (46.4%) developed abdominal obesity. A higher laver intake was significantly associated with a lower risk of abdominal obesity in both sexes. Compared with participants in the lowest category of laver intake, those in the highest category had a 28% lower risk among men (HR: 0.72; 95% CI: 0.58-0.89; p for trend = 0.0099) and a 33% lower risk among women (HR: 0.67; 95% CI: 0.54-0.84; p for trend = 0.0005). These associations remained significant after additional adjustment for overall diet quality. Conclusions: Higher habitual laver intake was associated with a lower risk of incident abdominal obesity in Korean adults. Further prospective and intervention studies are needed to confirm these findings.

Humans↗
PubMed1978

Isolation of the etiologic agent of Korean Hemorrhagic fever.

Lung tissues from 73 rodents (Apodemus agrarius coreae) gave specific immunofluorescent reactions when they reacted with sera from patients convalescing from Korean hemorrhagic fever. Similar staaining was observed in the lungs of A. agrarius inoculated with acute-phase sera obtained from two patients with this disease. The unidentified agent was successfully propagated in adult A. agrarius through eight passages representing a cumulative dilution of greater than 10(-17). Experimentally inoculated rodents developed specific fluorescent antigen in the lung, kidney, liver, parotid glands, and bladder. Organs, especially lungs, were positive beginning 10 days and continuing through 69 days after inoculation. The agent could not be cultivated in several types of cell cultures nor in laboratory animals. No fluorescence was observed when infected A. agrarius lung tissues were reacted with antisera to Marburg virus, Ebola virus, and serval arenaviruses. Diagnostic increases in immunofluorescent antibodies occurred in 113 of 116 severe and 11 of 34 milder cases of clinically suspected Korean hemorrhagic fever. Antibodies were present during the first week of symptoms, reached a peak at the end of the second week, and persisted for up to 14 years. Convalescent-phase sera from four persons suffering a similar disease in the Soviet Union were also positive for antibodies.

Animals↗
PubMed2026

Age- and sex-adjusted genomic differences between Korean and Beat AML cohorts.

Genomic profiling plays a central role in risk stratification and therapeutic decision-making in acute myeloid leukemia (AML), yet the clinical implications of population-specific genomic architectures remain incompletely defined. We conducted a prospective, multicenter study of 603 adults with newly diagnosed AML in Korea, integrating targeted sequencing of 83 recurrently mutated genes with comprehensive clinical annotation across treatment intensities, including allogeneic hematopoietic stem cell transplantation (allo-HSCT). For contextual comparison, genomic profiles were evaluated against the Beat AML cohort. The overall genomic landscape was broadly conserved, supporting shared core disease biology across populations. However, RUNX1::RUNX1T1, CEBPA, GATA2, KIT, and DDX41 mutations were more frequent in the Korean cohort, whereas FLT3 and NPM1 mutations were less common. These differences translated into a distinct distribution of European LeukemiaNet (ELN) 2022 risk categories, with implications for therapeutic stratification. Notably, most DDX41 alterations were germline (3.2%), highlighting the need for systematic germline evaluation with implications for genetic counseling and donor selection. Although unadjusted overall survival appeared longer in the Korean cohort, this difference was not significant after adjustment for key clinical variables. These findings indicate that population-specific genomic distributions reshape the clinical application of risk stratification and support population-aware precision medicine strategies in AML.

Journal Article↗
PubMed2026

Lifestyle Combination Patterns as Key Modifiable Factors for Type 2 Diabetes Mellitus Risk among Middle-Aged Korean Men.

BACKGRUOUND: The increasing prevalence of type 2 diabetes mellitus (T2DM) worldwide highlights the need to understand risk factors and effective prevention strategies. Although individual lifestyle factors associated with diabetes risk have been identified, research on their collective interactions is limited. This study aimed to identify lifestyle combination patterns in middle-aged Korean men and evaluate their impact on T2DM risk. METHODS: A total of 2,332 middle-aged men without T2DM at baseline (2001-2002) from the Korean Genome and Epidemiology Study (KoGES) cohort were included. T2DM incidence was tracked through the 8th follow-up survey (2017-2018). Lifestyle combination patterns were identified using factor analysis based on sociodemographic, lifestyle, and dietary data. Cox regression was used to assess T2DM incidence across patterns. RESULTS: Four lifestyle combination patterns were identified: 'Healthy Lifestyle,' 'Low Carb & High Protein,' 'High SES & Irregular Lifestyle,' and 'Bad Eating Habits.' The risk of developing T2DM varied across patterns. The 'Healthy Lifestyle' and 'Low Carb & High Protein' patterns showed a slight decrease in risk in T3, but the differences were not significant. The 'High SES & Irregular Lifestyle' pattern was associated with a higher T2DM risk in T3 than in T1 (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.05 to 1.55), but the association was attenuated after adjustment for family history. The 'Bad Eating Habits' pattern showed a 1.21-fold higher risk in T3 (HR, 1.21; 95% CI, 1.01 to 1.47). CONCLUSION: This study underscores the existence of distinct lifestyle combination patterns and their differential implications for T2DM risk. These findings support the need for tailored preventive strategies based on lifestyle patterns.

Humans↗
PubMed1976

Failure to prove arenavirus infection among the small mammals from an endemic area of Korean hemorrhagic nephrosonephritis.

In the light of recent knowledge on a complex of diseases caused by a new group of viruses, arenaviruses, virological studies largely directed toward small field mammals were undertaken during 1973-1974 aiming at etiological clarification of Korean hemorrhagic nephrosonephritis (KHNN). Specimens were collected in an endemic area of KHNN located north to northeast of Seoul. Virus isolation tests with 299 urine specimens and 131 mite pools recovered from small mammals and 14 acute stage sera from typical cases yielded negative results. Complement-fixation (CF) tests failed to detect antibodies against the antigens of Congo, lymphocytic choriomeningitis (LCM), Tacaribe, and Pichinde viruses among 366 small mammal sera. In addition, CF tests of 59 of the above sera against Apoi and Lassa virus antigens were negative. The results do not support the likelihood of an arenavirus being transmitted among Korean small field mammals, the overwhelming majority of which were Apodemus agrarius. A hypothesis that KHNN is caused by a virus of small field mammal origin was not proved within the technical limit of relatively unsophisticated methods employed herein.

Adolescent↗
PubMed1979

Etiological relation between Korean hemorrhagic fever and epidemic hemorrhagic fever in Japan.

The first case of epidemic hemorrhagic fever in Japan was seen in Osaka in 1960. The etiologic agent of this disease has not yet been isolated, but a close etiologic relation between Korean hemorrhagic fever and epidemic hemorrhagic fever in Japan has been suspected because of similarities in the clinical and pathological pictures of the two diseases. This relation has now been confirmed serologically by demonstrating specific immunofluorescent antibodies to Korean hemorrhagic fever virus in 19 of 20 sera obtained from subjects 7 to 17 years after an acute attack of epidemic hemorrhagic fever.

Adolescent↗
PubMed1979

Aetiological relation between Korean haemorrhagic fever and nephropathia epidemica.

A close aetiological relation between Korean haemorrhagic fever and nephropathia epidemica of Scandinavia has often been suggested because of similarities in their clinical picture and epidemiology. This relation has now been confirmed serologically; raised titres of antibody to Korean haemorrhagic fever agent and seroconversions have been found by the indirect fluorescent-antibody technique in 20 patients with nephropathia epidemica.

Acute Disease↗
PubMed2026

Genetic (Genomic) and Morphological Evidence Suggest That the Korean Endemic Fat Minnow (Rhynchocypris kumgangensis) and the Deogyu Population Represent Distinct Species.

Geographically disconnected populations of freshwater fishes often show ecological and genetic divergence in response to opposing selection differentials in different habitat environments, sometimes leading to the formation of ecotypes and even speciation. Nevertheless, evidence for the speciation through allopatric processes in freshwater fish systems remains scarce. Kumkang fat minnow (Rhynchocypris kumgangensis), a Korean endemic coldwater fish, has recently been suggested to diverge into a separate species (Rhynchocypris deogyuensis). However, the level of their genetic and ecological divergence remains largely unknown. We analyzed population genetic structure of R. kumgangensis together with R. deogyuensis using mitochondrial DNA (mtDNA) and eight newly developed microsatellite markers. Genetic divergence at mitogenome level was further assessed between the presumed two species. Moreover, we examined morphology between two groups by analyzing morphometric traits and also conducted geometric morphometrics on body shape. We found distinct population structure between R. kumgangensis and R. deogyuensis at both mtDNA and microsatellites. One remnant population of R. deogyuensis harbored only a single haplotype and showed a very high level of inbreeding. Comparative analysis of the mitogenomes showed approximately 2.9% divergence between R. kumgangensis and R. deogyuensis, supporting the species-level divergence. The analyses of both morphometric traits and geometric morphometrics indicated significant morphological divergence between the two species. The observed low values of length-weight relationship and condition factor for R. deogyuensis are likely to be attributed to effects of the elevated level of inbreeding and depleted genetic diversity. Overall, our combined genetic/genomic and morphological analyses suggest the considerable divergence between R. kumgangensis and R. deogyuensis, supporting the hypothesis that they are distinct species. The mechanisms underpinning how they speciate still need to be studied further in detail.

Deogyu fat minnow↗
PubMed2025

Climatic data sources and limitations of ecological niche models impact the estimations of historical ranges and niche overlaps in distantly related Korean salamanders.

BACKGROUND: Ecological niche models (ENMs) and analyses of niche overlap/divergence have become popular methods in ecology and evolutionary biology. These analyses rely on environmental data available from several databases. However, the influence of data sources on these analyses is rarely tested. Here, we test the impact of climatic data choice on the prediction of current and Plio-Pleistocene suitable habitats for two distantly related, but broadly sympatric, salamanders endemic to the Korean Peninsula. We ran MaxEnt separately on WorldClim and CHELSA climate data. We then hindcasted ENMs to five time periods of the Plio-Pleistocene, bracketing the estimated intraspecific divergence times for these species. We then quantified the differences in predictions between WorldClim- and CHELSA-based models. Also, given the sympatry and similar habitat requirements of the two species, we tested for niche overlaps using niche identity and background tests and tested the sensitivity of the results to climatic data choice. RESULTS: The ENMs successfully predicted contemporary suitable habitats for the two species. However, the predictions were highly sensitive to climatic data choice as well as variable combinations. The hindcasted ENMs produced contrasting predictions depending on the choice of climatic dataset and failed to predict suitable habitats for some Pleistocene time periods regardless of the climatic data choice. The niche analyses were also sensitive to climatic data choice, with results suggesting either niche overlaps or divergence depending on the climatic dataset used for the analyses. CONCLUSIONS: Our study highlights the influence of climatic data choice on the outcomes of ENMs and niche analyses. Our results also underscore the limitations of macroclimate-based ENMs, especially when the species is likely buffered from macroclimatic changes by microhabitat. We argue for the need for additional ecological, ecophysiological, and population genomic studies to better understand the range formation of these enigmatic species.

Animals↗
PubMed2026

Mortality and causes of death in the Korean Genome and Epidemiology Study (KoGES), 2001-2023.

The Korean Genome and Epidemiology Study (KoGES) is a large prospective cohort study established to investigate determinants of chronic disease. To evaluate overall and cause-specific mortality, KoGES records were linked to the official Causes of Death Statistics compiled by Statistics Korea. Of 211,562 participants the KoGES population-based cohorts, 211,428 were successfully linked to official mortality data through December 31, 2023, using resident registration numbers. Over a mean follow-up of 14.9 years, the linked cohort had an overall mortality rate of 5.8 deaths per 1,000 person-years; the rate was higher among men than among women (9.6 vs. 3.9 deaths per 1,000 person-years). Malignant neoplasms, heart disease, and cerebrovascular disease were the leading causes of death. As the cohort aged, deaths from causes such as pneumonia increased substantially, a pattern consistent with national mortality statistics. This linked dataset provides a basis for longitudinal analyses of chronic disease progression, survival outcomes, and cause-specific mortality using repeated epidemiologic measurements collected over more than 2 decades of follow-up.

Causes of death↗
PubMed2026

Genetic and Environmental Influences on Caffeine Intake in Korean Twins.

Caffeine intake may be influenced by both genetic and environmental factors. This study aimed to examine the genetic contribution to variation in coffee and tea drinking, as well as total caffeine intake. A total of 1,106 Korean twins, comprising 456 monozygotic and 97 dizygotic twin pairs aged 30 years or older, from the Healthy Twin Study were included. Structural equation models were used to assess heritability estimates and their 95% confidence intervals (CIs). Heritability (95% CI) was estimated at 0.29 (0.21, 0.37) for coffee drinking, 0.11 (0.02, 0.20) for tea drinking, and 0.27 (0.16, 0.38) for total caffeine intake, with the remaining variance in each trait attributed to unique environmental factors. The unique environmental factors contributed more substantially to coffee drinking than genetic factors during early adulthood, while the genetic contribution to tea drinking remained consistently low across all ages. In conclusion, coffee drinking, tea drinking, and total caffeine intake were partly heritable, with unique environmental factors playing a predominant role.

Humans↗
PubMed1979

Korean haemorrhagic fever in staff in an animal laboratory.

In March, 1975, and January, 1978, there were outbreaks of Korean haemorrhagic fever (K.H.F.) among staff in the animal laboratory of the clinical research building of Tohoku University hospital. 13 doctors and 1 veterinarian had K.H.F., and all except 1 had a mild but typical clinical course. K.H.F. antibody titres were significantly raised in all 14 patients. 12 other doctors working in the same room had no symptoms and no K.H.F. antibody. K.H.F. antibody was also detected in 3 animal technicians who had not been ill, but who had worked in the same room. Antibody was not detected in any of the 4 technicians who worked in different animal rooms in another building. Epidemiological studies suggest that laboratory rats were the source of the infection. High titres of K.H.F. antibody were most common in rats reared in the animal laboratory associated with the outbreak.

Adult↗
PubMed1979

Ultrastructural studies on the effects of Korean Panax ginseng on the theca interna of rat ovary.

An investigation was conducted to delineate the fine structure of steroid-producing ovarian theca interna cells following administration of Korean Panax ginseng to rats for 60 days. The cytoplasmic changes were observed in the ginseng-treated theca interna cells, increased number, size and density of the mitochondria, and increased size of the smooth surfaced endoplasmic reticulum, the rough surfaced endoplasmic reticulum and the Golgi apparatus. The nucleus and nucleolus were slightly enlarged and increased numbers of dense bodies were seen whereas lipid droplets were decreased in number. The changes may result from hyperfunction of the steroid-producing cells. Morphologic changes seen may represent stimulating effects on the steroid-producing cells of the theca interna in ginseng-treated animals.

Adipose Tissue↗