1,167 research outputs found
Environmental tobacco smoke and children's health
Passive exposure to tobacco smoke significantly contributes to morbidity and mortality in children. Children, in particular, seem to be the most susceptible population to the harmful effects of environmental tobacco smoke (ETS). Paternal smoking inside the home leads to significant maternal and fetal exposure to ETS and may subsequently affect fetal health. ETS has been associated with adverse effects on pediatric health, including preterm birth, intrauterine growth retardation, perinatal mortality, respiratory illness, neurobehavioral problems, and decreased performance in school. A valid estimation of the risks associated with tobacco exposure depends on accurate measurement. Nicotine and its major metabolite, cotinine, are commonly used as smoking biomarkers, and their levels can be determined in various biological specimens such as blood, saliva, and urine. Recently, hair analysis was found to be a convenient, noninvasive technique for detecting the presence of nicotine exposure. Because nicotine/cotinine accumulates in hair during hair growth, it is a unique measure of long-term, cumulative exposure to tobacco smoke. Although smoking ban policies result in considerable reductions in ETS exposure, children are still exposed significantly to tobacco smoke not only in their homes but also in schools, restaurants, child-care settings, cars, buses, and other public places. Therefore, more effective strategies and public policies to protect preschool children from ETS should be consolidated
Determinants of the subscription to bundled services and their effect on customer retention in the Korean communications sector
Since bundlesprovide price discountsto customers and have lock-in effects forbusinessesin the communicationssector, the number of bundlesubscribersisrapidly growing in many countries,including Korea.The consumerwelfareand marketing effects of bundleshavebeen welldocumented. Existing literature, however,has paid little attention to identifyingthe facets of benefitsand risks that influence subscriptions, the differences in switching costs between subscribers and non-subscribers, and the relationships among bundle satisfaction, customerretention, and switching costs. To address these gaps, we performed an empirical analysis using survey data from 550 individuals.Our findingsshow that concernabout lock-inand performanceas well as economicbenefits influencesubscriptionsto the bundles, switching costs arehigher for thesubscribersthan for stand-alone service users, and monetary switching costsof bundlesdirectly affect customer retention. These results show the lock-in effectsofswitching costsof bundlesin subscribersā decision-making, retention, and churn. The implications for regulatory policyand customer strategyare discussed
Mesenchymal Stem Cells Improve Wound Healing In Vivo via Early Activation of Matrix Metalloproteinase-9 and Vascular Endothelial Growth Factor
We investigated the effects of mesenchymal stem cells (MSCs) on wound healing using a three-dimensional (3D) collagen gel scaffold. Three circular full-thickness skin defects were created on the back of Sprague-Dawley rats. One site was covered with a 3D collagen gel containing 2 Ć 106 MSCs (MSCs+/3D collagen+). Another site was replaced with a 3D collagen gel without MSCs and the third site was left empty. The wound size was significantly reduced in the MSCs+/3D collagen+ sites. MSCs+/3D collagen+ sites exhibited the most neovascularization. FISH showed that Y-chromosome possessing cells were found within the dermis of MSCs+/3D collagen+ sites. Gelatin zymography revealed that the most intense expression of MMP-9 was detected early in the MSCs+/3D collagen+ sites. Our results indicate that MSCs upregulate the early expression of MMP-9 which induces the early mobilization of VEGF. Thus, MSCs appear to accelerate significantly wound healing via early activation of MMP-9 and VEGF
In vitro selection of salt-tolerant Ailanthus altissimaSwingle
Salt-tolerant cell lines of Ailanthus altissima were selected from callus derived protoplasts. MurashigeāSkoog (MS) liquid medium incorporated with various concentrations of NaCl was employed to enrich salt-tolerant A. altissima cell lines. Salt-resistant A. altissima cells were transferred on MS solid medium supplemented with 2.5 Ī¼M 2,4-dichlorophenoxy acetic acid (2,4-D), 0.5 Ī¼M benzyl adenine (BA) and various NaCl concentrations. The callus was cultured on MS medium containing NaCl for 5 months, to determine the survival rate as an index of salt tolerance. The measurement of growth parameters for salt-tolerant cells showed that the selected plant cell lines grew better than the unselected ones at all levels of NaCl tested. The salt-tolerant callus accumulated proline in correlation to the concentration of salts. Media supplemented with BA induced shoot differentiation of salt-resistant A. altissima cells
In Vitro Chemosensitivity Using the Histoculture Drug Response Assay in Human Epithelial Ovarian Cancer
The choice of chemotherapeutic drugs to treat patients with epithelial ovarian cancer has not depended on individual patient characteristics. We have investigated the correlation between in vitro chemosensitivity, as determined by the histoculture drug response assay (HDRA), and clinical responses in epithelial ovarian cancer. Fresh tissue samples were obtained from 79 patients with epithelial
ovarian cancer. The sensitivity of these samples to 11 chemotherapeutic agents was tested using the HDRA method according to established methods, and we analyzed the results retrospectively. HDRA showed that they were more chemosensitive to carboplatin, topotecan and belotecan, with inhibition rates of 49.2%, 44.7%, and 39.7%, respectively, than to cisplatin, the traditional drug of choice in epithelial ovarian cancer. Among the 37 patients with FIGO stage ā
¢/ā
£ serous adenocarcinoma
who were receiving carboplatin combined with paclitaxel, those with carboplatin-sensitive samples on HDRA had a significantly longer median disease-free interval than patients with carboplatin-
resistant samples (23.2 vs. 13.8 months, pļ¼0.05), but median overall survival did not differ significantly
(60.4 vs. 37.3 months, pļ¼0.621). In conclusion, this study indicates that HDRA could provide useful information for designing individual treatment strategies in patients with epithelial ovarian cancer
Negative regulation of ERĪ± by a novel protein CAC1 through association with histone demethylase LSD1
AbstractERĪ±, a critical transcriptional factor for breast cancer proliferation, is regulated by a complex binding repertoire that includes coactivators and corepressors. Here, we identified a novel class of ERĪ± coregulator called CAC1. The CoRNR box of CAC1 was required for the binding to and inactivation of ERĪ±. CAC1 also associated with histone demethylase LSD1 and suppressed LSD1-enhanced ERĪ± activity. CAC1 impaired recruitment of ERĪ± and LSD1 to the ERĪ±-responsive promoter, leading to greater H3K9me3 accumulation. This effect was reversed by CAC1 depletion. Finally, CAC1 increased paclitaxel-induced cell death in ERĪ±-positive MCF7 cells, which are paclitaxel-resistant. Overall, our study provides the first evidence that CAC1, associated with LSD1, functions as an ERĪ± corepressor, implicating a potential antitumor target in ERĪ±-positive breast cancer.Structured summary of protein interactionsER-alpha physically interacts with CAC1 by anti tag coimmunoprecipitation (View Interaction: 1, 2, 3)LSD1 physically interacts with CAC1 by anti tag coimmunoprecipitation (View interaction)CAC1 binds to ER-alpha by pull down (View interaction)CAC1 and ER-alpha colocalizebyfluorescence microscopy (View interaction
Comparison of Operational Definition of Type 2 Diabetes Mellitus Based on Data from Korean National Health Insurance Service and Korea National Health and Nutrition Examination Survey
Background We evaluated the validity and reliability of the operational definition of type 2 diabetes mellitus (T2DM) based on the Korean National Health Insurance Service (NHIS) database. Methods Adult subjects (ā„40 years old) included in the Korea National Health and Nutrition Examination Survey (KNHANES) from 2008 to 2017 were merged with those from the NHIS health check-up database, producing a cross-sectional dataset. We evaluated the sensitivity, specificity, accuracy, and agreement of the NHIS criteria for defining T2DM by comparing them with the KNHANES criteria as a standard reference. Results In the study population (n=13,006), two algorithms were devised to determine from the NHIS dataset whether the diagnostic claim codes for T2DM were accompanied by prescription codes for anti-diabetic drugs (algorithm 1) or not (algorithm 2). Using these algorithms, the prevalence of T2DM was 14.9% (n=1,942; algorithm 1) and 20.8% (n=2,707; algorithm 2). Good reliability in defining T2DM was observed for both algorithms (Kappa index, 0.73 [algorithm 1], 0.63 [algorithm 2]). However, the accuracy (0.93 vs. 0.89) and specificity (0.96 vs. 0.90) tended to be higher for algorithm 1 than for algorithm 2. The validity (accuracy, ranging from 0.91 to 0.95) and reliability (Kappa index, ranging from 0.68 to 0.78) of defining T2DM by NHIS criteria were independent of age, sex, socioeconomic status, and accompanied hypertension or dyslipidemia. Conclusion The operational definition of T2DM based on population-based NHIS claims data, including diagnostic codes and prescription codes, could be a valid tool to identify individuals with T2DM in the Korean population
- ā¦