Induction of B-cell lymphoma by UVB Radiation in p53 Haploinsufficient Mice

<p>Abstract</p> <p>Background</p> <p>The incidence of non-Hodgkin's lymphoma has increased over recent years. The exact etiology of lymphoma remains unknown. Ultraviolet light exposure has been associated with the development of internal lymphoid malignancies and some reports suggest that it may play a role in the development of lymphoma in humans. Here we describe the characterization and progression of lymphoma in p53 heterozygous mice exposed to UVB irradiation.</p> <p>Methods</p> <p>UVB-irradiated p53^+/-mice developed enlargement of the spleen. Isolated spleen cells were transplanted into Rag deficient hosts. The UV-induced tumor cells were analyzed by flow cytometry. The tumor cells were tagged with GFP to study their metastatic potential. SKY and karyotypic analysis were carried out for the detection of chromosomal abnormalities. Functional assays included in vitro class switch recombination assay, immunoglobulin rearrangement assay, as well as cytokine profiling.</p> <p>Results</p> <p>UVB-exposed mice showed enlargement of the spleen and lymph nodes. Cells transplanted into Rag deficient mice developed aggressive tumors that infiltrated the lymph nodes, the spleen and the bone marrow. The tumor cells did not grow in immune competent syngeneic C57Bl/6 mice yet showed a modest growth in UV-irradiated B6 mice. Phenotypic analysis of these tumor cells revealed these cells are positive for B cell markers CD19⁺, CD5⁺, B220⁺, IgM⁺and negative for T cell, NK or dendritic cell markers. The UV-induced tumor cells underwent robust in vitro immunoglobulin class switch recombination in response to lipopolysaccharide. Cytogenetic analysis revealed a t(14;19) translocation and trisomy of chromosome 6. These tumor cells secret IL-10, which can promote tumor growth and cause systemic immunosuppression.</p> <p>Conclusion</p> <p>UV-irradiated p53^+/-mice developed lymphoid tumors that corresponded to a mature B cell lymphoma. Our results suggest that an indirect mechanism is involved in the development of internal tumors after chronic exposure to UV light. The induction of B cell lymphoma in UV-irradiated p53 heterozygous mice may provide a useful model for lymphoma development in humans.</p

Examining the validity of the Athlete Engagement Questionnaire (AEQ) within a Portuguese sport setting

Sport psychology literature suggests that understanding engagement levels is pivotal to promote positive sporting experiences among athletes. The purpose of this study was to examine the psychometric properties of the Athlete Engagement Questionnaire among Portuguese sport athletes. Two distinct samples of Portuguese athletes from different competitive levels were collected, and the results of a confirmatory factor analysis demonstrated a good fit of the model to the data. A review of the psychometric properties indicated that all factors showed good composite reliability, convergent validity, and discriminant validity. In addition, a multi-groups analysis showed the invariance of the model in two independent samples providing evidence of cross validity. Implications of these results for scholars and coaches are discussed and guidelines for future studies are suggested

Athlete brand construction: A perspective based on fans’ perceptions

Abstract The purpose of this study was to develop a framework for understanding the antecedents and components of athlete brand. Based on a set of 21 interviews conducted in three different countries, a detailed framework is proposed including five antecedents and two components of athlete brand. The antecedents are media (social media, mass media, video games and major sport events), oral communications (word of mouth, and rumors and narratives), impression management, social agents (parents, family members, friends and community), and teams and sport (sport interest, team interest and team geographical location). In turn, the components of athlete brand are related with on-field attributes (behavior, team, achievements, style of play and skills) and off-field attributes (physical attraction, lifestyle, personal appeal, ethnicity and entertainment). Complementarily, these components of athlete brand are proposed to have an impact on fans' loyalty towards the athlete. Implications of these findings for building and managing athlete brand are discussed, and directions for future studies are provided

WHAT SHOULD BE SAID? INVESTIATING THE CONTENT OF VERBAL ENCOURAGEMENT CUES ON EXERCISE PERFORMANCE

J. R. Clavenna, S. Olsen, A.A.B. Cruz, S. Ullrich-French, C. P. Connolly. Washington State University, Pullman, WA Verbal encouragement (VE) is related to exercise performance, though it remains unclear what specific phrases lead to optimal performance results. Based on Achievement Goal Theory, VE can focus either on personal improvement (mastery climate) or established outcome standards (performance climate). Moreover, goal orientation (GO) may influence how an individual responds to different motivational climates created through VE. PURPOSE: We aimed to identify the impact of mastery VE (MVE) and performance VE (PVE) on exercise performance in 1RM bench press (1RM), PACER (PC), plank (PL), and push-up (PU) tasks. We examined differences in exercise performance by self-reported mastery GO (MGO) and performance GO (PGO). METHODS: Undergraduate students (N=30) were randomly assigned to three groups, MVE (N=10), PVE (N=9), and control (N=11). Baseline and experimental assessments were conducted for each performance task. A repeated measures ANOVA with a within subjects’ factor of visit and between subjects’ factor of VE group examined exercise performance differences. A secondary one-way ANOVA with a Tukey post hoc test examined differences among VE groups and performance improvements. RESULTS: Most participants (20 ± 1.2 years old) reported being physically active (~90%). Significantly higher PL improvements were identified with PVE compared to control (p=.001) and MVE (p=.033). PVE PL performance increased an average of 54 sec, MVE increased by 22 sec and control decreased by 2 sec. Significantly higher PU improvements were observed in PVE compared to control (p=.042), with no other significant PU improvements among other VE groups. No other significant differences in exercise improvements were noted when comparing MVE, PVE, and control. Analysis of variance showed a main effect of MGO on PC (F = 8.282, p = .009, ηp 2 = .274) and 1RM (F = 5.775, p = .025, ηp 2 = .208). No significant main effect was observed for PGO on exercise performance. CONCLUSION: Initial analyses suggest that PVE had a greater impact on improving PL and PU performance compared to MVE and control. MGO appears to have a greater influence on exercise performance in comparison to PGO. Increased sample size and diversity will likely provide a better understanding of impacts of VE and GO. Supported by ACSM Northwest Student Research Grant