Effects of chemical composition of ambient PM measured in Seoul on potential health risks and generation of reactive oxygen species.

This study assesses the health effects associated with the chemical species of ambient particulate matter (PM) with an aerodynamic diameter ≤2.5 μm (PM) in Seoul, focusing on identifying key chemical constituents and their sources. We employed two approaches to estimate health risks: (1) evaluating carcinogenic and noncarcinogenic risks using IRIS (Integrated Risk Information System) data from the US EPA (Environmental Protection Agency), and (2) quantifying the generation of hydroxyl radicals (·OH) following exposure to PM in surrogate lung fluid (SLF).

The impact of size-segregated particle properties on daily mortality in Seoul, Korea.

To investigate the causative component for certain health outcomes, the associations between the properties of ambient particles and cause-specific mortality (all-cause, cardiovascular, and respiratory-related mortality) measured in Seoul, Korea, from January 1, 2013, to December 31, 2016, were evaluated with a quasi-Poisson generalized additive model (GAM). The total mass of PM and PM moderately affected respiratory-related mortality but had almost no impact on all-cause and cardiovascular-related mortality. Among PM mass compositions, ammonium sulfate, which is in generally 300-500 nm as a secondary species, showed the most statistically significant effect on respiratory-related mortality at lag 4 (p < 0.

Seasonal characteristics of atmospheric water-soluble organic nitrogen in PM in Seoul, Korea: Source and atmospheric processes of free amino acids and aliphatic amines.

The seasonal characteristics of atmospheric water-soluble organic nitrogen (WSON) in particulate matter with a diameter of 2.5 μm or smaller (PM) were analyzed focusing on sources and atmospheric processing. Daily collected samples over 23 h (10:00-9:00) from 7 August 2018 to 31 December 2019 on quartz filters with a high-volume sampler at the Korea Institute of Science and Technology (KIST) in Seoul were considered.

Respiratory function declines in children with asthma associated with chemical species of fine particulate matter (PM) in Nagasaki, Japan.

Background: The differential effects of PM fractions on children's lung function remain inconclusive. This study aimed to examine whether lung function in asthmatic children was associated with increased PM fractions in urban areas in Nagasaki prefecture, Japan, where the air pollution level is relatively low but influenced by transboundary air pollution.

Methods: We conducted a multiyear panel study of 73 asthmatic children (boys, 60.

The major chemical constituents of PM and airborne bacterial community phyla in Beijing, Seoul, and Nagasaki.

Ambient particle (PM) samples were collected in three East Asian cities (Beijing, China; Seoul, South Korea; Nagasaki, Japan) from December 2014 to November 2015 to quantitatively investigate airborne bacteria at the phylum level. Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Cyanobacteria represented the top five airborne bacterial phyla in all three cities. The most dominant airborne phylum, Proteobacteria, was more prevalent during the winter (at rates of 67.

Long term trends of chemical constituents and source contributions of PM in Seoul.

PM was measured and analyzed between 2014 and 2015 in Seoul, and its sources were identified with a positive matrix factorization (PMF) to characterize chemical constituents and sources of the measured PM. To verify policy interventions in reducing PM levels in Korea, the results were compared with previously published results from 2003 to 2007 at the same study site. A total of 215 PM samples were collected and analyzed for 24 species, i.

Comparisons of doxycycline solution with talc slurry for chemical pleurodesis and risk factors for recurrence in South Korean patients with spontaneous pneumothorax.

Purpose: Talc slurry (TS) has been commonly used with high success rates in managing spontaneous pneumothroax (SP), but there were concerns of post-procedural complications. Alternatively, doxycycline solution (DS) was used successfully. This retrospective study aims to compare the effectiveness and safety between talc and doxycycline as a sclerosing agent and to investigate risk factors for recurrence in patients with SP.

Reactive oxygen species (ROS) activity of ambient fine particles (PM) measured in Seoul, Korea.

Substantial increase in level of particulate matter has raised concerns in South Korea recently. Ambient particulate matter is classified as Group I carcinogen (IARC, 2013) and multiple epidemiological studies has demonstrated adverse health effects due to exposure of particulate matter. Fine particulate matter (PM) which has a diameter <2.

Airborne Bacterial Communities in Three East Asian Cities of China, South Korea, and Japan.

The global diversity of airborne bacteria has not yet been studied, despite its importance in human health and climate change. Here, we focused on the diversity of airborne bacteria and their correlations with meteorological/environmental conditions in China, South Korea, and Japan. Beijing (China) had more diverse airborne bacteria, followed by Seoul (South Korea) and Nagasaki (Japan), and seasonal variations were observed.

Vascular and cardiac autonomic function and PM constituents among the elderly: A longitudinal study.

Background: Although epidemiologic studies have shown an association between the total mass of particulate matter <2.5μm in aerodynamic diameter (PM) and cardiovascular disease, few studies have examined PM constituents associated with vascular and cardiac autonomic dysfunction.

Methods: In this longitudinal study, we investigated the relationship between PM constituents and blood pressure (BP), and markers of the autonomic nervous system.

Age-specific prevalence of serrated lesions and their subtypes by screening colonoscopy: a retrospective study.

Background: Serrated lesions of the colorectum as categorized by pathology include hyperplastic polyps, sessile serrated adenomas without dysplasia, and traditional serrated adenomas with dysplasia. The aim of this study was to investigate the prevalence of various subtypes of serrated lesions by age.

Methods: In this study, 28,544 consecutive asymptomatic patients (aged 22-88 years) were evaluated during health check-ups involving colonoscopies performed by gastroenterologists at a single institution from 2005 to 2012.

Seroprevalence of Helicobacter pylori Infection in Korean Health Personnel.

Background/aims: The aims of this study were to evaluate whether doctors and nurses in a single hospital were at an increased risk of acquiring Helicobacter pylori infection in 2011 and to identify risk factors for H. pylori seroprevalence.

Methods: Nurses (n=362), doctors (n=110), health personnel without patient contact (medical control, n=179), and nonhospital controls (n=359) responded to a questionnaire during a health check-up, which included questions on socioeconomic status, education level, working years, and occupation in 2011.

Prevalence and risk factors of functional dyspepsia: a nationwide multicenter prospective study in Korea.

Goals: To evaluate the prevalence of functional dyspepsia (FD) and its risk factors.

Background: FD is a common disorder, but its negative influences greatly affect the quality of life. The predictive factors of FD are still ambiguous.

Nonalcoholic fatty liver disease is associated with coronary artery calcification.

Unlabelled: Nonalcoholic fatty liver disease (NAFLD) is related to risk factors of coronary artery disease, such as dyslipidemia, diabetes, and metabolic syndrome, which are closely linked with visceral adiposity. The aim of this study was to investigate whether NAFLD was associated with coronary artery calcification (CAC), which is used as a surrogate marker for coronary atherosclerosis independent of computed tomography (CT)-measured visceral adiposity. Out of 5,648 subjects who visited one of our health screening centers between 2003 and 2008, we enrolled 4,023 subjects (mean age, 56.

Effects of different dilutions of botulinum toxin type A treatment for children with cerebral palsy with spastic ankle plantarflexor: a randomized controlled trial.

Objective: The aim of this study was to investigate the influence of different volumes of saline vehicle on the effects of botulinum toxin type A in reducing ankle plantarflexor spasticity and improving gait pattern in children with cerebral palsy.

Design: Children with cerebral palsy having ankle plantarflexor spasticity were recruited. They were divided randomly into 2 groups.

Clinical outcome of rumination syndrome in adults without psychiatric illness: a prospective study.

Background And Aim: This prospective study was conducted to characterize the clinical features of adult rumination syndrome, in the absence of psychiatric illness, by applying newly modified clinical criteria, and to elucidate factors influencing outcomes after treatment.

Methods: Twenty-one adult patients diagnosed with rumination syndrome at a tertiary referral center over a 2-year period were enrolled in the study. All patients received supportive psychotherapy and medical treatment.

Clinical usefulness of subgrouping of patients with non-cardiac chest pain according to characteristic symptoms in Korea.

Background: Non-cardiac chest pain (NCCP) is a heterogeneous disorder. There is controversy about the associations between symptoms and causes in NCCP patients. The purpose of the present study was to evaluate the clinical usefulness of subgrouping according to characteristic symptoms in NCCP patients.

Autologous allogeneic amniotic membrane grafting in Stevens-Johnson syndrome.

We describe the use of autologous allogeneic amniotic membrane in ocular surface reconstruction. A 28-year-old woman with cicatricial entropion from Stevens-Johnson syndrome had recurrent keratinization of the tarsal conjunctiva. Amniotic membrane from the patient's own conceptus was stored and successfully used in ocular surface reconstruction with improvement of ocular symptoms.

Twenty-four-hour pattern of intraocular pressure in young adults with moderate to severe myopia.

Purpose: To characterize the 24-hour change of intraocular pressure (IOP) in young adults with moderate to severe myopia.

Methods: Nineteen young adults, ages 18 to 25 years, with moderate to severe myopia (myopia group) and 17 age-matched volunteers with emmetropia or mild myopia (control group) were housed for 1 day in a sleep laboratory. An 8-hour accustomed sleep period was assigned to each volunteer.