In vitro analysis of the interactions of the N-terminal domain of the southern cowpea mosaic virus coat protein with RNA and membrane

Southern cowpea mosaic virus (SCPMV) is a spherical RNA virus with T=3 icosahedral symmetry. The particle is composed of 180 subunits of the CP and one copy of the viral RNA. The CP has two domains, the random (R) domain formed by the N-terminal 64 amino acids (aa) of the CP and the shell (8) domain (aa 65-260). The R domain is highly basic in charge and is localized to the interior of the particle where it is proposed to interact with the viral RNA. The R domain may also interact with membranes since it has been previously shown that the SCPMV CP binds liposomes in the presence but not in the absence of the R domain. The RNA binding site of the R domain was identified by northwestern blot and by electrophoretic mobility shift assay (EMSA) using recombinant wild-type R domain protein (rWTR) that included aa 1-57 of the SCPMV CP and a C-terminal non-viral extension that contained two histidine tags and an S peptide tag (His-S tag domain). Deletions within the R domain revealed that the N-terminal 30 aa function in RNA binding. The R domain-RNA interaction was nonspecific with regard to RNA sequence and was sensitive to high salt concentrations suggesting that the interaction is predominantly electrostatic. The RNA binding site includes eleven basic residues, eight of which are located in the arginine-rich region between aa 22- 30. It was demonstrated using alanine substitution mutants that the basic residues of the arginine-rich region but not those present at positions 3, 4, and 7 are necessary for RNA binding. None of the basic residues within the arginine-rich region are specifically required for RNA binding, but the overall charge of the N-terminal 30 aa is important. Proline substitution mutations within the N-terminal 30 aa, and alanine substitutions for prolines at positions 18, 20, and 21 did not affect the RNA binding activity of the R domain. However, it was demonstrated by circular dichroism (CD) that the conformation of the N-terminal 30 aa of the R domain changes from a random coil to an a-helix in the presence of 50% trifluoroethanol (TFE). The ability of rWTR to interact with artificial membrane was also analyzed in vitro using a dye release assay. The results demonstrated that the R domain interacts with negatively charged but not neutral liposomes. Deletion of the N-terminal 16 aa of the R domain nearly abolished the membrane interaction activity. In addition, aa 17-30 were also shown to be important for the activity. The interaction was dependent upon the presence of phosphatidic acid (PA) or phosphatidylethanolamine (PE). The interaction was sensitive to high salt and acidic pH indicating that electrostatic interactions are involved in the liposome-R domain interaction. CD analysis and dye release assays of mutants with proline to alanine or alanine to proline substitutions within the N-terminal 30 residues of the R domain demonstrated a positive correlation between the extent of a-helical content in this region and the ability to lyse liposomes. A synthetic peptide (CP peptidei.30) corresponding to the N-terminal 30 aa of the SCPMV CP was also able to induce lysis of liposomes. The peptide underwent a conformational change from a random coil to an a-helix in the presence of negatively charged liposomes suggesting a possible role of protein secondary structure in the membrane interaction. These experiments demonstrated that the R domain of the SCPMV CP can bind RNA and interact with membranes. The roles of these activities in the SCPMV life cycle are discussed

The relationship between children's computer game usage and creativity in Korea

This study investigated the relationships among children?s creativity, computer games, natural play, TV, and their structured activities daily after school by the analysis of their time spent on computer games, and the other components with the Torrance Test of Creative Thinking (TTCT), using the statistical methods of MANOVA and SEM. Activity 5 of Verbal Form B and Activity 2 of Figural Forms B of the TTCT were used to measure students? verbal and figural creativity scores. Two hundreds and thirty eight 3rd and 6th grade students from one rural and one urban school in the Republic of Korea were studied. The study also examined whether any variables (i.e., gender, grade, location, achievement, genres of computer games and parental Social Economic Status) affected children?s creativity scores and computer game usage. Children using computer games heavily showed significantly higher scores on the scale of Figural Originality than those with moderate usage. Highly structured activity students had significantly higher scores on all Figural TTCT scales than did the moderately structured activity group. There was a significant location difference on Figural Originality and Figural Elaboration, parental SES, and time spent on TV. Time spent on free play did not show any differences on any TTCT scales. Time spent on TV was differently correlated with the Figural TTCT by parental SES. Third graders obtained significantly higher scores than 6th graders on all the Verbal TTCT and Figural Elaboration scales. In this study, the subjects showed a significant preference for Role Playing Game (RPG) and Casual games. Gender differences on preferences of game genres, time spent on computer games and starting period of computer use were found. The MANOVA among genres of computer games on the TTCT scores was significant. The path models showed that the parent factor had strong correlation with children?s figural creativity and the play factor was correlated more with verbal creativity

Graduate Student Recital: Kyung Jin Lee, Cello; Tong Sook Han, Piano; May 25, 1973

Centennial East Recital HallFriday EveningMay 25, 19738:15 p.m

Quality of Life Differences between Younger and Older Breast Cancer Patients

Purpose: This study was designed to investigate quality of life (QOL) differences between younger (<50 years) and older (≥50 years) breast cancer survivors and to determine the unique effect of age on QOL after adjusting age-correlated variables. Methods: One thousand two hundred fifty patients were enrolled. Clinicopatholgical and social parameters were reviewed and Functional Assessment of Cancer Therapy-Breast cancer instrument (FACT-B) and the Ladder of Life scale were used to measure the QOL. Among 1,250 eligible patients, 1,094 patients completed the questionnaire and were used for analysis. Chi-square test, t-test and a series of multiple regression analyses were conducted to verify age-related differences in QOL between two groups and to evaluate the unique contribution of age variable on QOL of breast cancer patients. Results: Significant socio-demographic and clinical differences existed based on age categories, includin

The Choreography of HIV-1 Proteolytic Processing and Virion Assembly

HIV-1 has been the target of intensive research at the molecular and biochemical levels for >25 years. Collectively, this work has led to a detailed understanding of viral replication and the development of 24 approved drugs that have five different targets on various viral proteins and one cellular target (CCR5). Although most drugs target viral enzymatic activities, our detailed knowledge of so much of the viral life cycle is leading us into other types of inhibitors that can block or disrupt protein-protein interactions. Viruses have compact genomes and employ a strategy of using a small number of proteins that can form repeating structures to enclose space (i.e. condensing the viral genome inside of a protein shell), thus minimizing the need for a large protein coding capacity. This creates a relatively small number of critical protein-protein interactions that are essential for viral replication. For HIV-1, the Gag protein has the role of a polyprotein precursor that contains all of the structural proteins of the virion: matrix, capsid, spacer peptide 1, nucleocapsid, spacer peptide 2, and p6 (which contains protein-binding domains that interact with host proteins during budding). Similarly, the Gag-Pro-Pol precursor encodes most of the Gag protein but now includes the viral enzymes: protease, reverse transcriptase (with its associated RNase H activity), and integrase. Gag and Gag-Pro-Pol are the substrates of the viral protease, which is responsible for cleaving these precursors into their mature and fully active forms (see Fig. 1A)

Graduate String Quartet: Kathryn Gray, Violin; Joung-Sook Noh, Violin; Ruth C. Boedecker, Viola; Kyung Jin Lee, Cello; November 28, 1972

Hayden AuditoriumTuesday EveningNovember 28, 19728:15 p.m

A study on Korean nursing students' educational outcomes

The purpose of this study was to describe outcome indicators of nursing education including critical thinking, professionalism, leadership, and communication and to evaluate differences among nursing programs and academic years. A descriptive research design was employed. A total of 454 students from four year baccalaureate (BS) nursing programs and two three-year associate degree (AD) programs consented to complete self-administered questionnaires. The variables were critical thinking, professionalism, leadership and communication. Descriptive statistics, χ2-test, t-tests, ANOVA, and the Tukey test were utilized for the data analysis. All the mean scores of the variables were above average for the test instruments utilized. Among the BS students, those in the upper classes tended to attain higher scores, but this tendency was not identified in AD students. There were significant differences between BS students and AD students for the mean scores of leadership and communication. These findings suggested the need for further research to define properties of nursing educational outcomes, and to develop standardized instruments for research replication and verification

Estimation of hospital-based HIV seroprevalence as a nationwide scale by novel method; 2002-2008 in Korea

<p>Abstract</p> <p>Background</p> <p>In Korea, approximately 70% of HIV-positive individuals are currently diagnosed in hospitals, while most HIV-positive patients were diagnosed at public health centers in 1980 s and 1990 s. However, there are no reporting systems to identify how many HIV tests are performed in the Korean hospitals different from public health centers and Blood centers. We estimated how many HIV tests were performed in hospitals and analyzed the nationwide hospital-based HIV seroprevalence in the present study.</p> <p>Methods</p> <p>Between 2002 and 2008, data included HIV tests on insurance claims in hospitals and the proportion of computerized insurance claims from the Health Insurance Review and Assessment Services. The number of HIV tests from the survey in the External Quality Assurance Scheme for hospital laboratories was collected to calculate the insurance claim proportion. HIV seroprevalence was estimated using data of tested individuals, including infected individuals. Statistical analysis was confirmed with the 95% confidence interval. Statistical significance was defined at p-values < 0.05.</p> <p>Results</p> <p>The number of HIV tests in hospitals increased from 2.7 million in 2002 to 5.0 million in 2008. The trend of HIV seroprevalence was decrease (1.5-1.3 per 10,000 individuals, P < 0.0028), except in 2002. The number of women tested was greater than men, and the proportion increased in older individuals and in small towns. Men had a higher annual HIV seroprevalence than women (P < 0.0001). The annual seroprevalence decreased in men (P = 0.0037), but was stable in women. The seroprevalence in the 30-39 year age group demonstrated higher than other age groups except 2008.</p> <p>Conclusions</p> <p>The nationwide hospital-based number of HIV tests and seroprevalence were estimated using a new method and seroprevalence trends were identified. This information will facilitate improvement in national HIV prevention strategies.</p