Background: To investigate the effect of parental social class on cancer mortality in children under 5 in Korea, two birth cohorts were constructed by linking national birth data to under-5 death data from the Statistics Korea for 1995–1999 (3,323,613 births) and 2010–2014 (2,297,876 births). Methods: The Cox proportional hazards model adjusted for covariates was used in this study. Results: Social inequalities of under-5 cancer mortality risk in paternal education and paternal employment status were greater in 2010–2014 than in 1995–1999. The gap of hazard ratio (HR) of under-5 cancer mortality between lower (high school or below) and higher (university or higher) paternal education increased from 1.23 (95% confidence interval, 1.041.46) in 1995–1999 to 1.45 (1.11–1.97) in 2010–2014; the gap of HR between parents engaged in manual work and non-manual work increased from 1.32 (1.12–1.56) in 1995–1999 to 1.45 (1.12–1.89) in 2010–2014 for fathers, and from 1.18 (0.7–1.98) to 1.69 (1.03–2.79) for mothers. When the parental social class was lower, the risk of under-5 cancer mortality was higher in not only adverse but normal births. Conclusion Social inequalities must be addressed to reduce the disparity in cancer mortality of children under 5 years old.

Background: Conventional modality requires several days observation by Holter monitor to differentiate atrial fibril‑ lation (AF) between Paroxysmal atrial fibrillation (PAF) and Non-paroxysmal atrial fibrillation (Non-PAF). Rapid and practical differentiating approach is needed. Objective: To develop a machine learning model that observes 10-s of standard 12-lead electrocardiograph (ECG) for real-time classification of AF between PAF versus Non-PAF. Methods: In this multicenter, retrospective cohort study, the model training and cross-validation was performed on a dataset consisting of 741 patients enrolled from Severance Hospital, South Korea. For cross-institutional validation, the trained model was applied to an independent data set of 600 patients enrolled from Ewha University Hospital, South Korea. Lasso regression was applied to develop the model. Results: In the primary analysis, the Area Under the Receiver Operating Characteristic Curve (AUC) on the test set for the model that predicted AF subtype only using ECG was 0.72 (95% CI 0.65–0.80). In the secondary analysis, AUC only using baseline characteristics was 0.53 (95% CI 0.45–0.61), while the model that employed both baseline characteris‑ tics and ECG parameters was 0.72 (95% CI 0.65–0.80). Moreover, the model that incorporated baseline characteristics, ECG, and Echocardiographic parameters achieved an AUC of 0.76 (95% CI 0.678–0.855) on the test set. Conclusions Our machine learning model using ECG has potential for automatic differentiation of AF between PAF versus Non-PAF achieving high accuracy. The inclusion of  Echocardiographic parameters further increases model per‑ formance. Further studies are needed to clarify the next steps towards clinical translation of the proposed algorithm.

Purpose: We explored the role of parental social class in preterm birth (PTB) and low birth weight (LBW) in association with child mortality in Korea. Materials and Methods: A total of 7,302,732 births in Korea between 1995 and 2007 were used for designing the national retrospective cohort study. Kaplan-Meier survival curves and Cox proportional hazard models were used to determine the risk of child death after adjusting for covariates. Results: Parental social class was associated with adverse birth outcomes and child mortality in Korea. Parental social class increased the strength of the relationship of adverse birth outcomes with child mortality. Child mortality was higher among PTB and LBW infants from parents with a lower social class than normal births from parents with a higher social class. In particular, the disparity in child mortality according to parental social class was greater for LBW and PTB than intrauterine growth retardation births.When one of the parents had a middle-school education or lower, the disparity in child mortality due to adverse birth outcomes was large regardless of the other spouse’s educational status. Inactive economic status for the father, as well as an occupation in manual labor by the mother, increased the risk of child mortality. Conclusion Strong relationships for social inequalities and adverse birth outcomes with inequalities in child mortality in South Korea were found in this study. Tackling social inequalities, as well as reducing adverse birth outcomes, are needed to reduce the disparities in child mortality in South Korea.

Objective: This study identified the distribution of lymphocele, as well as the factors associated with lymphocele formation, in patients undergoing pelvic and/or para-aortic lymph node dissection (PLND and/or PALND) for gynecologic malignancies. Methods: This study was retrospective, and data were collected from patients who underwent surgical procedures including lymphadenectomy due to gynecologic malignancies from March 2013 to May 2016. Lymphocele was defined by postoperative computer tomography within 2 weeks after surgery. Results: A total of 116 patients underwent lymphadenectomy, of whom, 47 (42.0%) developed lymphocele and 14 (12.1%) had symptomatic lymphocele formation. The affecting factors of lymphocele formation were PLND concomitant with PALND and a large amount of blood loss ≥600 mL (P=0.030 and P=0.006, respectively). All clinical factors were not significantly different between patients with symptomatic and asymptomatic lymphocele. Lymphocele developed more frequently in the left side (67.1%) of the body compared to the right side (48.7%), and in the pelvic area (75.9%) compared to the para-aortic area (24.1%, P<0.001, both). Conclusion Lymphocele formation is more prevalent in the left and pelvic area of the body compared to the right and paraaortic side. PLND concurrent with PALND and large amounts of blood loss were significant risk factors for lymphocele formation.

Objective: This study identified the distribution of lymphocele, as well as the factors associated with lymphocele formation, in patients undergoing pelvic and/or para-aortic lymph node dissection (PLND and/or PALND) for gynecologic malignancies. Methods: This study was retrospective, and data were collected from patients who underwent surgical procedures including lymphadenectomy due to gynecologic malignancies from March 2013 to May 2016. Lymphocele was defined by postoperative computer tomography within 2 weeks after surgery. Results: A total of 116 patients underwent lymphadenectomy, of whom, 47 (42.0%) developed lymphocele and 14 (12.1%) had symptomatic lymphocele formation. The affecting factors of lymphocele formation were PLND concomitant with PALND and a large amount of blood loss ≥600 mL (P=0.030 and P=0.006, respectively). All clinical factors were not significantly different between patients with symptomatic and asymptomatic lymphocele. Lymphocele developed more frequently in the left side (67.1%) of the body compared to the right side (48.7%), and in the pelvic area (75.9%) compared to the para-aortic area (24.1%, P<0.001, both). Conclusion Lymphocele formation is more prevalent in the left and pelvic area of the body compared to the right and paraaortic side. PLND concurrent with PALND and large amounts of blood loss were significant risk factors for lymphocele formation.

Purpose: Thrombotic stroke is a type of ischemic stroke characterized by motor dysfunction and memory impairments. In the present study, the effect of treadmill exercise on motor function and short-term memory was evaluated in relation with synaptic plasticity in the mice with photothrombotic stroke. Methods: Photothrombotic stroke was induced by cortical photothrombotic vascular occlusion. The mice in the treadmill exercise groups performed running on a motorized treadmill for 28 days. Motor function was determined using rota-rod test and foot fault test. Step-through avoidance task was conducted to evaluate short-term memory. Immunohistochemistry for 5-bromo-2′-deoxyuridine and doublecortin was conducted to detect new cell generation. Postsynaptic density protein 95, synaptophysin, brain-derived neurotrophic factor (BDNF), and tyrosine kinase B receptor (TrkB) were determined using western blot. The number of dendritic spines was determined using Golgi stain. Results: Treadmill exercise improved motor function and short-term memory in mice with the photothrombotic stroke. The infarct size was reduced and the number of dendritic spines and expression of postsynaptic density protein 95 and synaptophysin in the peri-infarct cortex and hippocampus were increased by treadmill exercise in photothrombotic stroke mice. Treadmill exercise enhanced neurogenesis through increasing the expression of the hippocampal BDNF and TrkB in photothrombotic stroke mice. Conclusions Treadmill exercise improved motor function and short-term memory through increasing synaptic plasticity and neurogenesis in photothrombotic stroke mice. Treadmill exercise can be used as an effective treatment strategy to improve brain function related to stroke.

PURPOSE: Hyperlipidemia, which promotes the development of atherosclerosis, ischemic stroke, and other forms of brain injury, can be induced by poloxamer-407. Berberine is a primary pharmacological active component of Coptidis Rhizoma that has a number of therapeutic activities. This study investigated the effects of berberine on poloxamer-407-induced brain inflammation by evaluating its effects on short-term memory, cell proliferation, inflammation, and apoptosis in the hippocampus. METHODS: To induce hyperlipidemia in a rat model, 500 mg/kg of poloxamer-407 was injected intraperitoneally. Berberine was orally administered to the rats in the berberine-treated groups once a day for 4 weeks. The step-down task avoidance task was performed to measure short-term memory. An analysis of serum lipids, immunohistochemistry for 5-bromo-2′-deoxyuridine, glial fibrillary acidic protein (GFAP), and ionized calcium-binding adapter molecule 1 (Iba1) in the dentate gyrus, and western blot analysis for Bax, Bcl-2, and cytochrome c in the hippocampus were performed. RESULTS: In hyperlipidemic rats, berberine reduced the levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol and increased the level of high-density lipoprotein cholesterol in hyperlipidemic rats. Berberine also increased cell proliferation and short-term memory, as well as decreasing the expression of GFAP, Iba1, Bax, and cytochrome c and increasing Bcl-2 expression. CONCLUSIONS Berberine treatment improved short-term memory in hyperlipidemia by increasing neuronal proliferation and inhibiting neuronal apoptosis. Berberine treatment also improved lipid metabolism.

PURPOSE: Goserelin is a drug used for chemical castration. In a rat model, we investigated whether surgical and chemical castration affected memory ability through the protein kinase A (PKA)/cyclic adenosine monophosphate response element-binding protein (CREB)/brain-derived neurotrophic factor (BDNF) and c-Raf/mitogen-activated protein kinases-extracellular signal–regulated kinases (MEK)/extracellular signal–regulated kinases (ERK) pathways in the hippocampus. METHODS: Orchiectomy was performed for surgical castration and goserelin acetate was subcutaneously transplanted into the anterior abdominal wall for chemical castration. Immunohistochemistry was done to quantify neurogenesis. To assess the involvement of the PKA/CREB/BDNF and c-Raf/MEK/ERK pathways in the memory process, western blots were used. RESULTS: The orchiectomy group and the goserelin group showed less neurogenesis and impaired short-term and spatial memory. Phosphorylation of PKA/CREB/BDNF and phosphorylation of c-Raf/MEK/ERK decreased in the orchiectomy and goserelin groups. CONCLUSIONS: Short-term memory and spatial memory were affected by surgical and chemical castration via the PKA/CREB/BDNF and c-Raf/MEK/ERK signaling pathways.
Abdominal Wall ; Adenosine Monophosphate ; Blotting, Western ; Castration ; Cyclic AMP-Dependent Protein Kinases ; Down-Regulation ; Goserelin ; Hippocampus ; Immunohistochemistry ; Memory ; Memory, Short-Term ; Models, Animal ; Neurogenesis ; Orchiectomy ; Phosphorylation ; Phosphotransferases ; Spatial Memory

BACKGROUND: This study investigates the relationship of socioeconomic status with adverse birth outcomes (low birth weight and preterm birth) and the relationship of socioeconomic status with infant mortality, using the birth cohort in Korea, 1995-2010. METHODS: In Korea, 8,648,035 births from 1995 to 2010 were studied with respect to social variation in adverse birth outcomes and infant mortality. The effect of social inequality was examined against adverse birth outcomes and infant mortality using multivariate logistic regression after controlling for other covariates. RESULTS: Social inequality were observed in adverse birth outcomes: low birth weight (LBW, 1,500-2,499 g), very LBW (1,000-1,499 g), and extremely LBW (500-999 g) as well as moderately preterm birth (PTB, 33-36 weeks), very PTB (28-32 weeks), extremely PTB (22-27 weeks), and infant mortality. The effect of social inequality was higher among moderately LBW (1,500-2,499 g) and PTB (33-36 weeks) than very or extremely LBW and PTB. CONCLUSION: The social inequality in adverse birth outcomes (low birthweight and preterm) and infant mortality existed and increased in Korea from 1995 to 2010. The effect of maternal education on adverse birth outcomes as well as infant mortality was apparent in the study results. Especially, social inequality in infant mortality was greater among the sub-normal births (low birth weight [1,500-2,499 g] or preterm birth [33-36 weeks]), which suggests, social interventions should aim at more among the subnormal births. This study suggest that tackling inequality in births as well as infant mortality should be focused on the social inequality itself.
Birth Weight ; Cohort Studies ; Education ; Female ; Humans ; Infant ; Infant Mortality* ; Infant* ; Infant, Extremely Low Birth Weight ; Infant, Low Birth Weight* ; Infant, Newborn ; Infant, Very Low Birth Weight* ; Korea ; Logistic Models ; Parturition ; Pregnancy ; Pregnancy Outcome* ; Pregnancy* ; Premature Birth ; Social Class ; Socioeconomic Factors

An 18-year-old man collapsed at his workplace while putting desiccant into a cylindrical mixer, 2 m x 1 m in dimension, which contained rubber powder. His coworker found him collapsed, and he was transported to a hospital by a 119 rescue team, where he died. Prior to the incident, liquid nitrogen had been placed into the mixer to lower the temperature of the rubber powder. There were no injuries or disease that could have caused death. Analysis of the gas in the mixer revealed that the O2 concentration had dropped to 3.7% in 2 minutes following addition of the liquid nitrogen. Therefore, it was concluded that the cause of death was asphyxia due to oxygen deficiency caused by liquid nitrogen evaporation.
Adolescent ; Anoxia* ; Asphyxia* ; Autopsy ; Cause of Death ; Humans ; Nitrogen* ; Oxygen* ; Rubber