Concentrations of blood and urinary arsenic species and their characteristics in general Korean population.

Arsenic (As) exposure has been extensively studied by investigating As species (e.g., inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA)) in urine, yet recent research suggests that blood could be a possible biomarker of As exposure. These investigations, however, were conducted on iAs-contaminated areas, and evidence on populations exposed to low levels of iAs is limited. This study aimed to describe the levels and distributions of As species in urine and blood, as well as to estimate methylation efficiency and related factors in the Korean population. Biological samples were obtained by the Korean Ministry of Food and Drug Safety. A total of 2025 urine samples and 598 blood samples were utilized in this study. Six As species were measured using ultra-high-performance liquid chromatography with inductively coupled plasma mass spectrometry (UPLC-ICP-MS): As(V), As(III), MMA, DMA, arsenobetaine (AsB), and arsenocholine (AsC). Multiple linear regression models were used to examine the relationship between As species (concentrations and proportions) and covariates. AsB was the most prevalent species in urine and blood. The relative composition of iAs, MMA, DMA, and AsC in urine and blood differed significantly. Consumption of blue-backed fish was linked to higher levels of AsB in urine and blood. Type of drinking water and multigrain rice consumption were associated with increased iAs concentration in urine. Except for iAs, every species had correlations in urine and blood in both univariate and multivariate analyses. Adolescents and smokers presented a lower methylation efficiency (higher %MMA and lower %DMA in urine) and females presented a higher methylation efficiency (lower %iAs, %MMA, and higher %DMA in urine). In conclusion, blood iAs concentration cannot represent urinary iAs; nonetheless, different compositions of urine and blood might reflect distinct information about iAs exposure. Further investigations on exposure factors and health are needed using low-exposure groups.

Joint segmentation and classification of hepatic lesions in ultrasound images using deep learning.

OBJECTIVES: To develop a convolutional neural network system to jointly segment and classify a hepatic lesion selected by user clicks in ultrasound images. METHODS: In total, 4309 anonymized ultrasound images of 3873 patients with hepatic cyst (n = 1214), hemangioma (n = 1220), metastasis (n = 1001), or hepatocellular carcinoma (HCC) (n = 874) were collected and annotated. The images were divided into 3909 training and 400 test images. Our network is composed of one shared encoder and two inference branches used for segmentation and classification and takes the concatenation of an input image and two Euclidean distance maps of foreground and background clicks provided by a user as input. The performance of hepatic lesion segmentation was evaluated based on the Jaccard index (JI), and the performance of classification was based on accuracy, sensitivity, specificity, and the area under the receiver operating characteristic curve (AUROC). RESULTS: We achieved performance improvements by jointly conducting segmentation and classification. In the segmentation only system, the mean JI was 68.5%. In the classification only system, the accuracy of classifying four types of hepatic lesions was 79.8%. The mean JI and classification accuracy were 68.5% and 82.2%, respectively, for the proposed joint system. The optimal sensitivity and specificity and the AUROC of classifying benign and malignant hepatic lesions of the joint system were 95.0%, 86.0%, and 0.970, respectively. The respective sensitivity, specificity, and the AUROC for classifying four hepatic lesions of the joint system were 86.7%, 89.7%, and 0.947. CONCLUSIONS: The proposed joint system exhibited fair performance compared to segmentation only and classification only systems. KEY POINTS: • The joint segmentation and classification system using deep learning accurately segmented and classified hepatic lesions selected by user clicks in US examination. • The joint segmentation and classification system for hepatic lesions in US images exhibited higher performance than segmentation only and classification only systems. • The joint segmentation and classification system could assist radiologists with minimal experience in US imaging by characterizing hepatic lesions.

Alterations in immune and renal biomarkers among workers occupationally exposed to low levels of trichloroethylene below current regulatory standards.

OBJECTIVES: The occupational exposure limit for trichloroethylene (TCE) in different countries varies from 1 to 100 ppm as an 8-hour time-weighted average (TWA). Many countries currently use 10 ppm as the regulatory standard for occupational exposures, but the biological effects in humans at this level of exposure remain unclear. The objective of our study was to evaluate alterations in immune and renal biomarkers among workers occupationally exposed to low levels of TCE below current regulatory standards. METHODS: We conducted a cross-sectional molecular epidemiology study of 80 healthy workers exposed to a wide range of TCE (ie, 0.4-229 ppm) and 96 comparable unexposed controls in China, and previously reported that TCE exposure was associated with multiple candidate biological markers related to immune function and kidney toxicity. Here, we conducted further analyses of all of the 31 biomarkers that we have measured to determine the magnitude and statistical significance of changes in the subgroup of workers (n=35) exposed to <10 ppm TCE compared with controls. RESULTS: Six immune biomarkers (ie, CD4+ effector memory T cells, sCD27, sCD30, interleukin-10, IgG and IgM) were significantly decreased (% difference ranged from -16.0% to -72.1%) and one kidney toxicity marker (kidney injury molecule-1, KIM-1) was significantly increased (% difference: +52.5%) among workers exposed to <10 ppm compared with the control group. These associations remained noteworthy after taking into account multiple comparisons using the false discovery rate (ie, <0.20). CONCLUSION: Our results suggest that occupational exposure to TCE below 10 ppm as an 8-hour TWA may alter levels of key markers of immune function and kidney toxicity.

Trends and Correlates of High-Risk Alcohol Consumption and Types of Alcoholic Beverages in Middle-Aged Korean Adults: Results From the HEXA-G Study.

BACKGROUND: We aimed to report the prevalence and correlates of high-risk alcohol consumption and types of alcoholic beverages. METHODS: The baseline data of the Health Examinees-Gem (HEXA-G) study participants, including 43,927 men and 85,897 women enrolled from 2005 through 2013, were used for analysis. Joinpoint regression was performed to estimate trends in the age-standardized prevalence of alcohol consumption. Associations of demographic and behavioral factors, perceived health-related effects, social relationships, and the diagnostic history of diseases with alcohol consumption were assessed using multinomial logistic regression. RESULTS: The prevalence of alcohol consumption remained higher in men during the study period and increased in women. The amount of alcohol consumed has increased in women, especially that from beer and makgeolli, a traditional Korean fermented rice wine. Older participants were less likely to be high-risk drinkers (men and women who drink more than 40 or 20 g/day of alcohol, respectively) and drink Soju, a distilled liquor, and beer, and more likely to drink makgeolli. Educational level was negatively associated with high-risk drinking. However, it was positively associated with the consumption of strong spirits and wine. Smoking was associated with high-risk drinking and the consumption of soju and strong spirits. Engaging in regular exercise and having stress were associated with drinking all types of beverages except for soju. CONCLUSIONS: Sex-specific trends in alcohol consumption were influenced by demographic, behavioral, and perceived health-related factors. The findings will help improve the understanding of alcohol-related problems and provide evidence for establishing country-specific policies and campaigns in Korea.

Association between occupational exposure to trichloroethylene and serum levels of microRNAs: a cross-sectional molecular epidemiology study in China.

OBJECTIVES: The objective of our study was to evaluate the association between occupational exposure to trichloroethylene (TCE), a suspected lymphomagen, and serum levels of miRNAs in a cross-sectional molecular epidemiology study of TCE-exposed workers and comparable unexposed controls in China. METHODS: Serum levels of 40 miRNAs were compared in 74 workers exposed to TCE (median: 12 ppm) and 90 unexposed control workers. Linear regression models were used to test for differences in serum miRNA levels between exposed and unexposed workers and to evaluate exposure-response relationships across TCE exposure categories using a three-level ordinal variable [i.e., unexposed, < 12 ppm, the median value among workers exposed to TCE) and ≥ 12 ppm)]. Models were adjusted for sex, age, current smoking, current alcohol use, and recent infection. RESULTS: Seven miRNAs showed significant differences between exposed and unexposed workers at FDR (false discovery rate) < 0.20. miR-150-5p and let-7b-5p also showed significant inverse exposure-response associations with TCE exposure (Ptrend= 0.002 and 0.03, respectively). The % differences in serum levels of miR-150-5p relative to unexposed controls were - 13% and - 20% among workers exposed to < 12 ppm and ≥ 12 ppm TCE, respectively. CONCLUSIONS: miR-150-5p is involved in B cell receptor pathways and let-7b-5p plays a role in the innate immune response processes that are potentially important in the etiology of non-Hodgkin lymphoma (NHL). Further studies are needed to replicate these findings and to directly test the association between serum levels of these miRNAs and risk of NHL in prospective studies.

Mortality among diagnostic medical radiation workers in South Korea, 1996-2015.

OBJECTIVES: To evaluate the risk for all-cause and cause-specific mortality in diagnostic medical radiation workers in South Korea. METHODS: The study population included all diagnostic medical radiation workers enrolled in the National Dosimetry Registry (NDR) between 1996 and 2011. NDR data were linked with mortality data obtained from national registries through 2015. Standardised mortality ratios (SMRs) and relative standardised mortality ratios (rSMRs) were calculated for external comparison and for adjustment of the cohort's overall healthiness. RESULTS: A total of 1099 deaths (974 in men and 125 in women) were reported from among 80 837 medical radiation workers. The SMRs for all causes of death were significantly lower than expected in both men (SMR 0.45, 95% CI 0.42 to 0.48) and women (SMR 0.49, 95% CI 0.41 to 0.58). No excesses were observed for any specific cause of death. The findings were similar by job title, calendar year of entry and year of birth. However, relative to all causes of death, mortality from all cancers (rSMR 1.60, 95% CI 1.41 to 1.82), leukaemia, colon cancer, stomach cancer and diseases of the circulatory system increased significantly among male workers. The results for female workers were limited due to small number of deaths; however, the rSMR for all cancers was significantly elevated (rSMR 1.70, 95% CI 1.17 to 2.46). CONCLUSIONS: This cohort showed lower mortality among diagnostic medical radiation workers than in the general population. However, occupational factors may have been involved in the increased relative mortality for several causes of death.

The radiologic technologists' health study in South Korea: study design and baseline results.

PURPOSE: To describe the study design, methods, and baseline results of a prospective cohort of radiologic technologists which we have initiated in South Korea. METHODS: The cohort participants were enrolled through a self-administered questionnaire survey administered from April 2012 to May 2013. Survey data were linked with radiation dosimetry, a cancer registry, and health insurance data by personal identification numbers. A nationwide representative survey was also conducted using a stratified random sampling design with face-to-face interviews. RESULTS: A total of 12,387 radiologic technologists were enrolled, which accounted for approximately 63% of all diagnostic radiologic technologists working in South Korea. For nationwide survey, 585 workers were interviewed using the detailed questionnaire, and buccal cells were also collected by scraping the inside of the cheek. The majority of study subjects were under 50-year-old and male workers. The average annual effective dose of radiation declined both men (from 2.75 to 1.43 mSv) and women (from 1.34 to 0.95 mSv) over the period of 1996-2011. A total of 99 cancers (66 cancers in men and 33 in women) were reported from 1992 to 2010. The standardized incidence ratio of all cancer combined was significantly lower in men (SIR = 0.75, 95% CI 0.58-0.96) than general population, but the ratios for thyroid cancer were significantly higher than expected among both men and women. CONCLUSIONS: This cohort provides comprehensive information on work activities and health status of diagnostic radiologic technologists. In addition, the nationwide representative sample provides unique opportunities compared with previous radiologic technologist studies.

Trend of blood lead, mercury, and cadmium levels in Korean population: data analysis of the Korea National Health and Nutrition Examination Survey.

This study was performed to assess the recent trends in lead, mercury, and cadmium levels in the blood among Korean adult population. The geometric means and 95 % confidence intervals (CIs) of blood lead, mercury, and cadmium concentrations were calculated using the data of the subjects from the third (2005, n = 1997), fourth (2008, n = 2005; 2009, n = 1991), and fifth (2010, n = 1989; 2011, n = 2014) Korea National Health and Nutrition Examination Survey. Blood lead levels in 2005, 2008, 2009, 2010, and 2011 declined to 2.61 µg/dL (2.51-2.71), 2.32 µg/dL (2.27-2.37), 2.29 µg/dL (2.23-2.35), 2.09 µg/dL (2.04-2.13), and 1.99 µg/dL (1.94-2.05), respectively. Blood mercury levels were 4.19 µg/L (3.99-4.39), 4.73 µg/L (4.57-4.89), 4.25 µg/L (4.09-4.41), 3.64 µg/L (3.49-3.80), and 3.08 µg/L (2.95-3.22), respectively, which indicated an increase in 2008 compared with those in 2005, and a clear downward trend from 2008 to 2011. Blood cadmium levels were 1.52 µg/L (1.47-1.57), 0.93 µg/L (0.89-0.97), 0.94 µg/L (0.90-0.98), 0.89 µg/L (0.87-0.92), 0.86 µg/L (0.83-0.89), respectively, which indicated very high levels in 2005, but a downward trend since 2008. Although the lead, mercury, and cadmium levels in the blood of the Korean adult population are on the decline, they are still relatively high compared with those for the population of the USA, Canada, and Germany. Thus, continuous biological monitoring and measures to reduce these levels are needed in Korea.

Learning Controllable ISP for Image Enhancement.

We present a plug-and-play Image Signal Processor (ISP) for image enhancement to better produce diverse image styles than the previous works. Our proposed method, ContRollable Image Signal Processor (CRISP), explicitly controls the parameters of the ISP that determine output image styles. ISP parameters for high-quality (HQ) image styles are encoded into low-dimensional latent codes, allowing fast and easy style adjustments. We empirically show that CRISP covers a wide range of image styles with high efficiency. On the MIT-Adobe FiveK dataset, CRISP can very closely estimate the reference styles produced by human experts and achieves better MOS with diverse image styles. Compared with the state-of-the-art method, our ISP comprises only 19 parameters, allowing CRISP to have 2× smaller parameters and 100× reduced FLOPs for an image output. CRISP outperforms previous works in PSNR and FLOPs with several scenarios for style adjustments.

Learning to Learn Task-Adaptive Hyperparameters for Few-Shot Learning.

The objective of few-shot learning is to design a system that can adapt to a given task with only few examples while achieving generalization. Model-agnostic meta-learning (MAML), which has recently gained the popularity for its simplicity and flexibility, learns a good initialization for fast adaptation to a task under few-data regime. However, its performance has been relatively limited especially when novel tasks are different from tasks previously seen during training. In this work, instead of searching for a better initialization, we focus on designing a better fast adaptation process. Consequently, we propose a new task-adaptive weight update rule that greatly enhances the fast adaptation process. Specifically, we introduce a small meta-network that can generate per-step hyperparameters for each given task: learning rate and weight decay coefficients. The experimental results validate that learning a good weight update rule for fast adaptation is the equally important component that has drawn relatively less attention in the recent few-shot learning approaches. Surprisingly, fast adaptation from random initialization with ALFA can already outperform MAML. Furthermore, the proposed weight-update rule is shown to consistently improve the task-adaptation capability of MAML across diverse problem domains: few-shot classification, cross-domain few-shot classification, regression, visual tracking, and video frame interpolation.