A three-year autoregressive cross-lagged panel analysis on nicotine dependence and average smoking.

OBJECTIVES: Previous studies have been limited to the use of cross sectional data to identify the relationships between nicotine dependence and smoking. Therefore, it is difficult to determine a causal direction between the two variables. The purposes of this study were to 1) test whether nicotine dependence or average smoking was a more influential factor in smoking cessation; and 2) propose effective ways to quit smoking as determined by the causal relations identified. METHODS: This study used a panel dataset from the central computerized management systems of community-based smoking cessation programs in Korea. Data were stored from July 16, 2005 to July 15, 2008. 711,862 smokers were registered and re-registered for the programs during the period. 860 of those who were retained in the programs for three years were finally included in the dataset. To measure nicotine dependence, this study used a revised Fagerström Test for Nicotine Dependence. To examine the relationship between nicotine dependence and average smoking, an autoregressive cross-lagged model was explored in the study. RESULTS: The results indicate that 1) nicotine dependence and average smoking were stable over time; 2) the impact of nicotine dependence on average smoking was significant and vice versa; and 3) the impact of average smoking on nicotine dependence is greater than the impact of nicotine dependence on average smoking. CONCLUSIONS: These results support the existing data obtained from previous research. Collectively, reducing the amount of smoking in order to decrease nicotine dependence is important for evidence-based policy making for smoking cessation.

FGF-2 inhibits TNF-α mediated apoptosis through upregulation of Bcl2-A1 and Bcl-xL in ATDC5 cells.

FGF-2 is involved in cell survival, proliferation, apoptosis, and angiogenesis in a wide variety of cells. FRGRs, PI3K and MAP kinases are well known mediators of FGF signaling. Despite its known roles during many developmental processes, including osteogenesis, there are few known targets of FGF-2. In the present study, we identified Bcl2-A1 and Bcl-xL as two prominent targets involved in promoting cell survival. Pretreatment of ATDC5 cells with FGF-2 increased cell survival, while siRNAs specific for Bcl2-A1 and Bcl-xL compromised the anti- apoptotic effect of FGF-2, sensitized the cells to apoptosis triggered by TNF-α. Chemical inhibition of FGFR, NFkB, and PI3K activity by PD173074, pyrrolidine dithiocarbamate, and LY294002 respectively abrogated the FGF-2-mediated induction of Bcl2-A1 and Bcl-xL expression. Taken together, our data demonstrate that a subset of Bcl2 family proteins are the targets of FGF-2 signaling that promotes the survival of ATDC5 cells.

Application of social network analysis to health care sectors.

OBJECTIVES: This study aimed to examine the feasibility of social network analysis as a valuable research tool for indicating a change in research topics in health care and medicine. METHODS: Papers used in the analysis were collected from the PubMed database at the National Library of Medicine. After limiting the search to papers affiliated with the National Institutes of Health, 27,125 papers were selected for the analysis. From these papers, the top 100 non-duplicate and most studied Medical Subject Heading terms were extracted. NetMiner V.3 was used for analysis. Weighted degree centrality was applied to the analysis to compare the trends in the change of research topics. Changes in the core keywords were observed for the entire group and in three-year intervals. RESULTS: The core keyword with the highest centrality value was "Risk Factor," followed by "Molecular Sequence Data," "Neoplasms," "Signal Transduction," "Brain," and "Amino Acid Sequence." Core keywords varied between time intervals, changing from "Molecular Sequence Data" to "Risk Factors" over time. "Risk Factors" was added as a new keyword and its social network was expanded. The slope of the keywords also varied over time: "Molecular Sequence Data," with a high centrality value, had a decreasing slope at certain intervals, whereas "SNP," with a low centrality value, had an increasing slope at certain intervals. CONCLUSIONS: The social network analysis method is useful for tracking changes in research topics over time. Further research should be conducted to confirm the usefulness of this method in health care and medicine.

Prevalence and genetic characterization of respiratory syncytial virus (RSV) in hospitalized children in Korea.

Human respiratory syncytial virus (HRSV) is the most common respiratory pathogen among infants and young children. To investigate the prevalence and genetic characteristics of HRSVs circulating in South Korea, we analyzed medical records of patients and performed molecular analysis of the G-protein gene of viruses detected from nasopharyngeal aspirates (NPA) of admitted patients at the Pediatrics Department of Chungbuk National University Hospital from April 2008 to April 2010. Epidemiological data revealed that the prevalence of HRSV infection was high during both winter seasons (October 2008 to February 2009 and November 2009 to February 2010). Of the 297 positive NPA specimens from infants or children tested, 67% were identified as HRSV-A while 33% were HRSV-B. The HRSV subgroup B was the most dominant in December 2008, but its dominance was dramatically replaced by HRSV subgroup A strains by February 2009. Phylogenetic analysis of the G protein sequences of HRSVs revealed novel genotypes within the HRSV-A (genotype CB-A) and B (genotypes BA11 and CB-B) subgroups in South Korea in addition to other strains identified in other countries. Molecular analysis also revealed genetic variability at the C-terminal end of the G proteins of the two HRSV subgroups, suggesting selection pressure in this region, which may potentially impact immune recognition. This is the first report of these HRSV variants in South Korea, indicating active genetic evolution of HRSV strains. Therefore, this study provides information on the molecular epidemiology of current HRSVs in the country and presents data for comparative analysis with other HRSV strains circulating worldwide.

Rapid evolution of low-pathogenic H9N2 avian influenza viruses following poultry vaccination programmes.

To investigate whether currently circulating H9N2 avian influenza viruses (AIVs) in domestic poultry have evolved in Korean poultry since 2007, genetic and serological comparisons were conducted of H9N2 isolates from poultry slaughterhouses from January 2008 to December 2009. The isolation rate was relatively low in 2008 but increased gradually from January 2009 onwards. Genetic and phylogenetic analyses revealed that reassortant viruses had emerged, generating at least five novel genotypes, mostly containing segments of a previously prevalent domestic H9N2 virus lineage (Ck/Korea/04116/04-like). It was noteworthy that the N2 genes of some H9N2 isolates (genotypes D, E and F) were derived from those of H3N2-like viruses commonly isolated among domestic ducks in live-poultry markets. Animal challenge studies demonstrated that the pathogenicity of Ck/Korea/SH0906/09 (genotype B) and Ck/Korea/SH0912/09 (genotype F) in domestic avian species was altered due to reassortment. Furthermore, serological analysis revealed that the isolates were antigenically distinct from previous Korean H9N2 viruses including Ck/Korea/01310/01. Such antigenic diversity was illustrated further in experiments using H9N2-immunized chickens, which could not inhibit the replication and transmission of challenge viruses from each genotype. These results suggest that H9N2 viruses from domestic poultry have undergone substantial evolution since 2007 by immune selection as a result of vaccinal and natural immunity, coupled with reassortment. Taken together, this study demonstrates that periodical updating of vaccine strains, based on continuous surveillance data, is an important issue in order to provide sufficient protectivity against AIV infections.