Act on the Registration and Evaluation of Chemicals (K-REACH) and replacement, reduction or refinement best practices

Objectives - Korea’s Act on the Registration and Evaluation of Chemicals (K-REACH) was enacted for the protection of human health and the environment in 2015. Considering that about 2000 new substances are introduced annually across the globe, the extent of animal testing requirement could be overwhelming unless regulators and companies work proactively to institute and enforce global best practices to replace, reduce or refine animal use. In this review, the way to reduce the animal use for K-REACH is discussed. Methods - Background of the enforcement of the K-REACH and its details was reviewed along with the papers and regulatory documents regarding the limitation of animal experiments and its alternatives in order to discuss the regulatory adoption of alternative tests. Results - Depending on the tonnage of the chemical used, the data required ranges from acute and other short-term studies for a single exposure route to testing via multiple exposure routes and costly, longer-term studies such as a full two-generation reproducibility toxicity. The European Registration, Evaluation, Authorization and Restriction of Chemicals regulation provides for mandatory sharing of vertebrate test data to avoid unnecessary duplication of animal use and test costs, and obligation to revise data requirements and test guidelines “as soon as possible” after relevant, validated replacement, reduction or refinement (3R) methods become available. Furthermore, the Organization for Economic Cooperation and Development actively accepts alternative animal tests and 3R to chemical toxicity tests. Conclusions - Alternative tests which are more ethical and efficient than animal experiments should be widely used to assess the toxicity of chemicals for K-REACH registration. The relevant regulatory agencies will have to make efforts to actively adopt and uptake new alternative tests and 3R to K-REACH

Delayed presentation of cerebellar and spinal cord infarction as a complication of computed tomography-guided transthoracic lung biopsy: a case report

INTRODUCTION: Computed tomography-guided transthoracic needle biopsy is a common diagnostic procedure that is associated with various complications including pneumothorax, parenchymal hemorrhage, and hemoptysis. A systemic air embolism is a very rare (0.06 to 0.21%) but potentially fatal complication. CASE PRESENTATION: A 70-year-old Korean male was admitted to our hospital for evaluation of a solitary pulmonary nodule located adjacent to the right inferior pulmonary vein in the medial basal segment of the right lower lobe. A computed tomography-guided needle biopsy was performed by a radiologist using a coaxial needle. A computed tomography image obtained immediately after the biopsy showed intraluminal free air in the proximal ascending aorta. He complained of a mild electrical current sensation in both lower extremities. After three hours he complained of neurological deficit in both lower extremities as well as voiding difficulty. The brain and spine magnetic resonance images showed a right cerebellar and spinal cord infarction at the T8-10 levels. CONCLUSIONS: We report a case of air embolism to the cerebellum and spinal cord causing infarction presenting with an initial symptom of mild electrical current sensation in both lower extremities during the transthoracic needle biopsy. For this potentially fatal complication, early recognition, followed by prompt therapy is critical to reducing morbidity and mortality

Staphylococcal enterotoxin sensitization in a community-based population : a potential role in adult-onset asthma

Background: Recent studies suggest that Staphylococcus aureus enterotoxin sensitization is a risk factor for asthma. However, there is a paucity of epidemiologic evidence on adult-onset asthma in community-based populations. Objective: We sought to evaluate the epidemiology and the clinical significance of staphylococcal enterotoxin sensitization in community-based adult populations. Methods: The present analyses were performed using the baseline data set of Korean adult population surveys, consisting of 1080 adults (mean age=60.2years) recruited from an urban and a rural community. Questionnaires, methacholine challenge tests, and allergen skin tests were performed for defining clinical phenotypes. Sera were analysed for total IgE and enterotoxin-specific IgE using ImmunoCAP. Results: Staphylococcal enterotoxin sensitization (0.35kU/L) had a prevalence of 27.0%. Risk factors were identified as male sex, current smoking, advanced age (61years), and inhalant allergen sensitization. Current asthma was mostly adult onset (18years old) and showed independent associations with high enterotoxin-specific IgE levels in multivariate logistic regression tests. In multivariate linear regressions, staphylococcal enterotoxin-specific IgE level was identified as the major determinant factor for total IgE level. Conclusions and Clinical Relevance: Staphylococcal enterotoxin sensitization was independently associated with adult-onset asthma in adult community populations. Strong correlations between the enterotoxin-specific IgE and total IgE levels support the clinical significance. The present findings warrant further studies for the precise roles of staphylococcal enterotoxin sensitization in the asthma pathogenesis

The role of social support and social networks in smoking behavior among middle and older aged people in rural areas of South Korea: A cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Although the number of studies on anti-smoking interventions has increased, studies focused on identifying social contextual factors in rural areas are scarce. The purpose of this study was to explore the role of social support and social networks in smoking behavior among middle and older aged people living in rural areas of South Korea.</p> <p>Methods</p> <p>The study employed a cross-sectional design. Participants included 1,057 adults, with a mean age of 60.7 years, residing in rural areas. Information on participants' tobacco use, stress, social support, and social networks was collected using structured questionnaires. The chi-square test, the t-test, ANOVA, and logistic regression were used for data analysis.</p> <p>Results</p> <p>The overall smoking prevalence in the study was 17.4% (men, 38.8%; women, 5.1%). Overall, stress was high among women, and social support was high among men. Smokers had high levels of social support (t = -2.90, p = .0038) and social networks (t = -2.22, p = .0271), as compared to non- and former smokers. Those in the high social support group were likely to be smokers (AOR = 2.21, 95% CI 1.15-4.26). Women with moderate social ties were less likely to smoke (AOR = 0.18, 95% CI 0.05-0.61).</p> <p>Conclusion</p> <p>There was a protective role of a moderate social network level among women, and a high level of social support was associated with smoking behaviors in rural areas. Findings suggest the need for a comprehensive understanding of the functions and characteristics of social contextual factors including social support and social networks in order to conduct more effective anti-smoking interventions in rural areas.</p

Effects of epicatechin, a crosslinking agent, on human dental pulp cells cultured in collagen scaffolds

Objective The purpose of this study was to investigate the biological effects of epicatechin (ECN), a crosslinking agent, on human dental pulp cells (hDPCs) cultured in collagen scaffolds. Material and Method To evaluate the effects of ECN on the proliferation of hDPCs, cell counting was performed using optical and fluorescent microscopy. Measurements of alkaline phosphatase (ALP) activity, alizarin red staining, and real-time polymerase chain reactions were performed to assess odontogenic differentiation. The compressive strength and setting time of collagen scaffolds containing ECN were measured. Differential scanning calorimetry was performed to analyze the thermal behavior of collagen in the presence of ECN. Results Epicatechin increased ALP activity, mineralized nodule formation, and the mRNA expression of dentin sialophosphoprotein (DSPP), a specific odontogenic-related marker. Furthermore, ECN upregulated the expression of DSPP in hDPCs cultured in collagen scaffolds. Epicatechin activated the extracellular signal-regulated kinase (ERK) and the treatment with an ERK inhibitor (U0126) blocked the expression of DSPP. The compressive strength was increased and the setting time was shortened in a dose-dependent manner. The number of cells cultured in the ECN-treated collagen scaffolds was significantly increased compared to the cells in the untreated control group. Conclusions Our results revealed that ECN promoted the proliferation and differentiation of hDPCs. Furthermore, the differentiation was regulated by the ERK signaling pathway. Changes in mechanical properties are related to cell fate, including proliferation and differentiation. Therefore, our study suggests the ECN treatment might be desirable for dentin-pulp complex regeneration

Effects of epicatechin, a crosslinking agent, on human dental pulp cells cultured in collagen scaffolds

Objective The purpose of this study was to investigate the biological effects of epicatechin (ECN), a crosslinking agent, on human dental pulp cells (hDPCs) cultured in collagen scaffolds. Material and Method To evaluate the effects of ECN on the proliferation of hDPCs, cell counting was performed using optical and fluorescent microscopy. Measurements of alkaline phosphatase (ALP) activity, alizarin red staining, and real-time polymerase chain reactions were performed to assess odontogenic differentiation. The compressive strength and setting time of collagen scaffolds containing ECN were measured. Differential scanning calorimetry was performed to analyze the thermal behavior of collagen in the presence of ECN. Results Epicatechin increased ALP activity, mineralized nodule formation, and the mRNA expression of dentin sialophosphoprotein (DSPP), a specific odontogenic-related marker. Furthermore, ECN upregulated the expression of DSPP in hDPCs cultured in collagen scaffolds. Epicatechin activated the extracellular signal-regulated kinase (ERK) and the treatment with an ERK inhibitor (U0126) blocked the expression of DSPP. The compressive strength was increased and the setting time was shortened in a dose-dependent manner. The number of cells cultured in the ECN-treated collagen scaffolds was significantly increased compared to the cells in the untreated control group. Conclusions Our results revealed that ECN promoted the proliferation and differentiation of hDPCs. Furthermore, the differentiation was regulated by the ERK signaling pathway. Changes in mechanical properties are related to cell fate, including proliferation and differentiation. Therefore, our study suggests the ECN treatment might be desirable for dentin-pulp complex regeneration

Arctic-North Pacific Coupled Impacts on the Late Autumn Cold in North America

The Pacific Decadal Oscillation (PDO) is known to bring an anomalously cold (warm) period to southeastern (northwestern) North America during the cold season of its positive phase through a Rossby wave linkage. This study provides evidence that the remote connection between the North Pacific and the downstream temperature over central North America is strengthened by the warm arctic conditions over the Chukchi and East Siberian Sea, especially in the late autumn season. The modulation effect of the Arctic manifests itself as an altered Rossby wave response to a transient vorticity forcing that results from an equatorward storm track shift, which is induced collaboratively by the PDO and the warm Arctic. This observational finding is supported by two independent modeling experiments: 1) an idealized coupled GCM experiment being nudged toward the warm arctic surface condition and 2) a simple stationary wave model (SWM) experiment forced by transient eddy forcing