Search

Airborne particulate matter (PM) is a major health hazard worldwide and is a key factor in lung cancer, which remains the most common type of malignancy and the leading cause of cancer-related deaths. DNA methylation is a critical mechanism underlying the detrimental effects of PM, however, the molecular link between PM exposure and lung cancer remains to be elucidated. N-α-acetyltransferase 10 (NAA10) is involved in the cell cycle, migration, apoptosis, differentiation, and proliferation. In order to investigate the role of NAA10 in PM-induced pathogenesis processes leading to lung cancer, we determined the expression and methylation of NAA10 in normal human bronchial epithelial (NHBE) cells treated with PM10, PM10-polycyclic aromatic hydrocarbons (PAH), and PM2.5 and evaluated the prognostic value of the NAA10 methylation status in lung cancer patients. Exposure to all PM types significantly increased the expression of NAA10 mRNA and decreased the methylation of the NAA10 promoter in NHBE cells compared with the mock-treated control. NAA10 hypomethylation was observed in 9.3% (13/140) of lung cancer tissue samples and correlated with NAA10 transcriptional upregulation. Univariate and multivariate analyses revealed that NAA10 hypomethylation was associated with decreased survival of patients with lung cancer. Therefore, these results suggest that PM-induced hypomethylation of the NAA10 may play an important role in the pathogenesis of lung cancer and may be used as a potential prognostic biomarker for lung cancer progression. Further studies with large numbers of patients are warranted to confirm our findings. [ABSTRACT FROM AUTHOR]

The role of Class-F fly ash in the removal of phosphate from aqueous solutions and the removal mechanism were quantitatively investigated. The relative contributions of precipitation and adsorption with various pH conditions showed that precipitation was predominant under alkaline conditions, whereas adsorption was effective under acidic conditions. The precipitation accounted for 79% of the total phosphate removal without adjusting the pH of the solution. This result suggests that the phosphate was predominantly removed by precipitation with fly ash, and that adsorption on hydroxylated oxides may have contributed to the removal of phosphate. The precipitate was revealed to be calcium hydrogen phosphate (CaHPO4) from X-ray absorption fine structure analysis. The adsorption process was expressed well by the Freundlich isotherm and phosphate adsorption by fly ash is favorable (n = 1.308). [ABSTRACT FROM AUTHOR]

Background: Persistent organic pollutants (POPs), despite their considerably low levels in humans, are an increasing concern for the general populations given their various adverse health problems, including metabolic and carcinogenic effects. DNA methylation deregulation is thought to be a key mechanism in the development of human chronic diseases including cancer. Methods: In an attempt to identify biomarkers monitoring low-dose exposure and hazard, we explored whether organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) may influence the methylation of tumour suppressor gene E-cadherin (CDH1) using peripheral blood cells from 364 healthy Korean subjects. Results: CDH1 methylation was observed in 78.3% of study subjects. Serum concentrations of OCPs or PCBs compounds were higher in CDH1 methylation-positive subjects than in methylation-negative ones. After adjusting for various covariates, the odds ratio of CDH1 methylation of the summary measure of PCBs were 1.0, 2.5 (95% confidence interval: 1.2-5.3), 3.6 (1.6-8.1), 3.6 (1.4-8.6), and 2.5 (1.1-5.7) across quintiles of PCBs (Ptrend = 0.01). The values of OCPs were 1.0, 0.9, 1.2, 2.4 (1.0-5.9), and 1.7 (Ptrend = 0.05). Conclusions: In this exploratory study with a small sample, CDH1 methylation might be served as the epigenetic biomarker associated with POPs exposure and adverse health effect. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the magnetic resonance imaging (MRI) findings of labyrinthine hemorrhage as a cause of sudden sensorineural hearing loss (SSNHL). Methods: MRI scans of 59 patients with SSNHL were retrospectively analyzed and compared to clinical features and audiometry data. MR images included pre-enhanced T1-weighted, 3D FLAIR volume isometric turbo spin-echo acquisition (VISTA), post-enhanced T1-weighted and 4-h-delayed enhanced FLAIR VISTA, and 3D thin-section proton density-weighted images. Results: High labyrinth signals were seen on pre-enhanced T1-weighted and 3D FLAIR VISTA images with no enhancement for 6 of 59 (10.2%) patients with SSNHL. In these six patients with presumed inner-ear hemorrhage, high signal intensity was seen in the endolymphatic and perilymphatic portions of the labyrinth on T1-weighted and 3D FLAIR VISTA images. In patients with SSNHL with nonhemorrhagic causes such as vestibular schwannoma or labyrinthitis, high signal or labyrinthine enhancement was seen only in the perilymphatic portion of the labyrinth on pre- or post-enhanced 3D FLAIR VISTA images. Conclusions: MRI using pre-enhanced T1-weighted, 3D FLAIR VISTA, and post-enhanced T1-weighted, 4-h delayed enhanced FLAIR VISTA images is able to identify labyrinthine hemorrhage as the cause of SSNHL. High signals in both the endolymphatic and perilymphatic portions of the labyrinth on pre- or post-enhanced 3D FLAIR VISTA images without enhancement indicate labyrinthine hemorrhage. [ABSTRACT FROM AUTHOR]

Alcohol use disorders (AUD) are defined as alcohol abuse and alcohol dependence, which create a substantial public health problem worldwide. To date, no therapeutic can effectively solve these problems. They are complex diseases characterized by both genetic and environmental factors. DNA methylation can act as a downstream effector of environmental signals and account for multi-factorial nature of the disease. Global DNA methylation of peripheral blood cells has recently been proposed as a potential biomarker for disease risk.Aluelements host one-quarter of CpG dinucelotides in the genome to function as proxies for global DNA methylation. In this study, we evaluated theAlumethylation in the peripheral blood DNA of healthy volunteers and AUD patients using the pyrosequencing technology. TheAlumethylation level is significantly higher in AUD compared to healthy controls (23.4 ± 1.6 versus 22.1 ± 1.0,t = 7.83,p < 0.0001). Moreover, significant correlation was found betweenAlumethylation and alcohol use disorders identification test score (r = 0.250,p < 0.0001), alcohol problem (r = 0.294,p < 0.0001), and life position (r = –0.205,p = 0.0005). Overall, these novel findings indicate that alcohol-related increase inAlumethylation might play a complex role in the etiology and pathogenesis of AUD. Further studies are required to elucidate the mechanisms underlying this relationship. [ABSTRACT FROM PUBLISHER]

Promoter hypermethylation of the O6-methylguanine-DNA methyltransferase (MGMT) DNA repair gene is important during carcinogenesis. We explored whether organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), were associated with hypermethylation of the MGMT gene promoter in peripheral leukocytes among 368 Koreans without cancer. Hypermethylation decreased as OCPs increased (Ptrend = 0.02), while PCB concentrations showed an inverted U-shaped association (Pquadratic < 0.01). The prevalence of MGMT promoter hypermethylation was highest within the 2nd quintile of the PCB summary score (28.4%), while it was only 2.7% in the upper 10% score. Chronic exposure to these chemicals may affect methylation of the MGMT promoter, with possibly non-monotonic dose response relationships. [ABSTRACT FROM AUTHOR]

In order to examine the changes in a biological community in the South Sea of Korea that is caused by the installation of an artificial upwelling structure during the summer season when the forming of the stratification is the strongest, the researchers evaluate the water's temperature and nutrients, the standing crops and species diversity of phytoplankton and zooplankton, and the benthic organisms. The forming depth of Maximum Thermocline of Water Column (MTWC) is elevated after installing an artificial upwelling structure. Also, instead of showing a clear stratification where the concentration of nutrients increases as the depth of the sea increases, the distribution of nutrients after installing an artificial upwelling structure has changed, showing a lower degree of stratification by causing the mixing of the water mass. Compared to 2005, when the artificial upwelling structure was first introduced, the standing crop of phytoplankton and zooplankton has increased by 58.2 and 30.0 times in 2008, thus showing a tendency to increase as the size of the artificial upwelling structure becomes bigger. Also, the species diversity index of phytoplankton and zooplankton has increased and the size of the artificial upwelling structure has become greater. When the environment underwater around the artificial upwelling structure was examined in 2008, the underwater environment, arthropods such asBalanus albicostatus, mollusks such asPatinopecten yessoensisandBatillus cornutus, echinoderms such asAsterina pectiniferaandComanthus japonica, chordates such asHalocynthia roretzi, and fishes such asSebastes inermisandOplegnathus fasciatuswere found, thus forming a benthic environment. [ABSTRACT FROM PUBLISHER]

Ampicillin was coupled to dextran of average molecular weight 9,000 or 81,200 via the cyanogen bromide method. The degree of drug substituted per glucose unit (DSG) was varied from O.104 to 0.028 (by weight bases: 22. 1-5.9%) depending on the ratio of the reactants. Water solubility of dextran-linked ampicillin increased compared with free ampicillin, and the solubility decreased as the amount of ampicillin substituted increased. Plasma concentration of ampicillin, which appeared after intravenous administration of dextran-linked ampicillin in rats, was higher than when free ampicillin was administered, and the more so, the higher the molecular weight of dextran. Plasma half-life of dextran-linked ampicillin was two times longer than that of free ampicillin in rats. Antibacterial activities of dextran-linked ampicillin were evaluated against Staphylococcus aureus, Bacillus substillis, and Escherichia coli at two concentration levels according lo the cup-plate method by measuring the diameter of inhibition zone, which was comparable to that of free ampicillin. [ABSTRACT FROM AUTHOR]