310 research outputs found
Expression of three forms of melanoma growth stimulating activity (MGSA)/gro in human retinal pigment epithelial cells
PURPOSE: To characterize mRNA expression and protein production of the cytokine MGSA/gro in human retinal pigment epithelial (RPE) cells and to determine whether expression of MGSA/gro is modulated by serum and the cytokines interleukin 1 beta (IL-1 beta), tumor necrosis factor alpha (TNF alpha), or transforming growth factor beta (TGF beta) mediators implicated in proliferative vitreoretinopathy (PVR). METHODS: Reverse-transcription polymerase chain reaction was used to determine the steady-state mRNA expression of three forms of MGSA/gro, alpha, beta, and gamma, by cultured human RPE cells in the presence or absence of recombinant IL-1 beta, TNF alpha, or TGF beta, or when serum-starved cells were re-fed with medium containing serum. Immunocytochemistry was used to characterize RPE cell-associated MGSA/gro protein, and immunoprecipitation of MGSA/gro from cell-conditioned medium was used to demonstrate MGSA/gro secretion. RESULTS: MGSA/gro mRNA was expressed minimally under basal conditions. Expression for all three forms of MGSA/gro mRNA was induced in a dose- and time-dependent manner after exposure to IL-1 beta, to a lesser extent after exposure to TNF alpha, but not after exposure to TGF beta. Serum induced MGSA/gro alpha and gamma transcripts, but not beta transcripts. Cell-associated MGSA/gro was identified on RPE cells grown in the absence of cytokines, but MGSA/gro was not secreted under these conditions. Exposure to IL-1 beta did not consistently cause increased cell-associated MGSA/gro; however, IL-1 beta induced secretion of MGSA/gro in a time-dependent manner. CONCLUSION: MGSA/gro is produced by human RPE in response to mediators implicated in PVR. Because MGSA/gro is a pleiotropic modulator of cell proliferation and inflammation, it may contribute to the intraocular wound healing response that characterizes PVR
A Review of the Effect of Management Practices on Campylobacter Prevalence in Poultry Farms.
Poultry is frequently associated with campylobacteriosis in humans, with Campylobacter jejuni being the most usual Campylobacter associated with disease in humans. Far-reaching research on Campylobacter was undertaken over the past two decades. This has resulted in interventions being put in place on farms and in processing plants. Despite these interventions, coupled with increased media coverage to educate the consumer on Campylobacter prevalence and campylobacteriosis, human health incidents are still high. Recent research is now shifting toward further understanding of the microorganisms to challenge interventions in place and to look at further and more relevant interventions for the reduction in human incidents. Farm practices play a key role in the control of colonization within poultry houses and among flocks. Prevalence at the farm level can be up to 100% and time of colonization may vary widely between flocks. Considerable research has been performed to understand how farm management and animal health practices can affect colonization on farms. This review will focus on farm practices to date as a baseline for future interventions as the microorganism becomes better understood. Further research is required to understand the chicken microbiome and factors influencing vertical transmission. The persistence of Campylobacter in animal and environmental reservoirs within and around farms requires further investigation to tailor farm practices toward preventing such reservoirs. IMPLICATIONSÂ This review gives an overview of farm practices and their effect on Campylobacter prevalence in poultry. Various elements of farm practices have been captured in this review
Youth\u27s Strategies for Staying Safe and Coping With the Stress of Living in Violent Communities.
Youth living in urban environments of pervasive violence are exposed to a variety of violence-related stressors. This qualitative descriptive study sought to ascertain how community-dwelling youth perceived exposure to violence and how these youth identified and used available resources. The intent of this community-based participatory research study was to help inform the design of a youth violence prevention center intervention. Semi-structured interviews were conducted with a purposive sample of 18 youth ages 10-16. Youth reported high levels of exposure to neighborhood violence. A theme of identifying and navigating safe and unsafe places emerged. Other stressors were more proximal and included interpersonal issues and conflicts. Youth used neighborhood and individual resources to cope with stressors. Youth maintained a high level of vigilance and developed clear strategies to safely navigate violent neighborhoods. Implications for youth due to the constant vigilance and exquisite sensitivity to stressors of chronic neighborhood violence are discussed
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Effect of the Planet Health Intervention on Eating Disorder Symptoms in Massachusetts Middle Schools, 2005–2008
Introduction: The Planet Health obesity prevention curriculum has prevented purging and abuse of diet pills (disordered weight control behavior [DWCB]) in middle-school girls in randomized trials, but the effects of Planet Health on DWCB when implemented by schools under dissemination conditions are not known. Methods: Massachusetts Department of Public Health and Blue Cross Blue Shield of Massachusetts disseminated Planet Health as part of the 3-year, Healthy Choices obesity prevention program in middle schools. We conducted an evaluation in 45 schools from fall 2005 to spring 2008. We gathered data from school staff to quantify intervention activities, and we gathered anonymous cross-sectional survey data from students on DWCB at baseline and Year 3 follow-up (n = 16,369). Multivariate logistic analyses with generalized estimating equations examined the effect of intervention activities on odds of students reporting DWCB at follow-up. Results: Students in schools reaching a high number of youth with Planet Health lessons on reducing television viewing had lower odds of DWCB at follow-up (odds ratio [OR], 0.80 per 100 lesson-exposures; 95% confidence interval [CI], 0.74–0.85). In addition, reduced odds of DWCB at follow-up were found in schools with active staff teamwork (OR, 0.76; 95% CI, 0.66–0.86) and the presence of programs addressing television viewing goals with staff (OR, 0.38; 95% CI, 0.28–0.53). Conclusion: Combined evidence from efficacy and effectiveness trials and now from dissemination research indicates that appropriately designed obesity prevention programs can achieve DWCB prevention on a large scale
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