University of Nebraska Omaha

About: University of Nebraska Omaha is a education organization based out in Omaha, Nebraska, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 4526 authors who have published 8905 publications receiving 213914 citations. The organization is also known as: UNO & University of Omaha.

Estrogen Mediation of Breast Tumor Formation Involves Estrogen Receptor-Dependent, as Well as Independent, Genotoxic Effects

Abstract: Long-term exposure to estrogens influences the development of breast cancer in women, but the precise mechanisms involved are not clearly defined. Our working hypothesis is that estrogen modulates this process by two separate processes. One involves the binding of estradiol to estrogen receptor (ER) alpha with stimulation of cell proliferation. Errors in DNA occurring during replication result in fixed mutations when not repaired. The other process results from the formation of genotoxic metabolites of estradiol, which can bind to DNA, cause depurination, and result in mutations. Our collaborative group, funded by a Department of Defense Center of Excellence grant, has examined this hypothesis using a variety of experimental methods. Estradiol and its catechol-estrogen metabolite 4-OH-estradiol causes mutations in cell culture systems and can transform benign MCF-10F cells, allowing them to cause tumors in SCID mice. We have demonstrated loss of heterozygosity and gains and losses of DNA segments by comparative genomic hybridization methodology. The depurinated estradiol-guanine and -adenine adducts are measurable in MCF-7 breast cancer cells in culture and in mouse mammary tissue. The double transgenic, alpha estrogen receptor knockout/Wnt-1 knockin mouse model allows us to dissect out the separate effects of ER-mediated and ER-independent actions of estradiol. Knock out of the ER alpha delays the onset of breast tumors in this model, demonstrating a role of receptor-mediated actions. Oophorectomy delays the onset of tumors and reduces overall incidence, providing evidence for an ER-independent effect. Taken together, these data suggest that both ER-dependent and genotoxic ER-independent effects of estradiol mediate breast cancer development.

Changes in Psychosocial Factors and Physical Activity Frequency among Third- to Eighth-Grade Girls Who Participated in a Developmentally Focused Youth Sport Program: A Preliminary Study.

Abstract: BACKGROUND: Despite the numerous physiological, psychological, and academic benefits of physical activity (PA), declines in PA levels among girls have been observed over the last decade. The purpose of this preliminary study was to assess the short-term changes pertaining to Girls on the Run and Girls on Track developmentally focused youth sport programs (DYS) on global self-esteem, body image, commitment to PA, and PA frequency. METHODS: This preliminary study employed a nonexperimental, one-group, pre- and postintervention study design using a 29-item paper-and-pencil assessment tool (n = 1034). RESULTS: Paired sample t-tests from pre- to postintervention revealed statistically significant differences in self-esteem (p < .001), body size satisfaction (p < .001), and vigorous PA frequency (p < .001). Stratification by the number of times participating in the intervention revealed the greatest changes at first participation followed with continued improvements in self-esteem (p = .013) and body size satisfaction (p < .001) for those participating in a second time. Age differences were also observed between participants ≤10 years old and 11–15 years; in that significant improvements in commitment to PA (p = .003) were observed for the older girls. CONCLUSIONS: Findings suggest DYS programs Girls on the Run and Girls on Track may produce beneficial changes in self-esteem, body size satisfaction, PA commitment, and PA frequency. Although the findings from the current report are preliminary, they suggest that DYS programs designed exclusively for girls may provide the necessary framework to promote PA to achieve the numerous associated benefits.

Structure of the 5′ Nontranslated Region of the Coxsackievirus B3 Genome: Chemical Modification and Comparative Sequence Analysis

Abstract: Coxsackievirus B3 (CVB3) is a picornavirus which causes myocarditis and pancreatitis and may play a role in type I diabetes. The viral genome is a single 7,400-nucleotide polyadenylated RNA encoding 11 proteins in a single open reading frame. The 5' end of the viral genome contains a highly structured nontranslated region (5'NTR) which folds to form an internal ribosome entry site (IRES) as well as structures responsible for genome replication, both of which are critical for virulence. A structural model of the CVB3 5'NTR, generated primarily by comparative sequence analysis and energy minimization, shows seven domains (I to VII). While this model provides a preliminary basis for structural analysis, the model lacks comprehensive experimental validation. Here we provide experimental evidence from chemical modification analysis to determine the structure of the CVB3 5'NTR. Chemical probing results show that the theoretical model for the CVB3 5'NTR is largely, but not completely, supported experimentally. In combination with our chemical probing data, we have used the RNASTRUCTURE algorithm and sequence comparison of 105 enterovirus sequences to provide evidence for novel secondary and tertiary interactions. A comprehensive examination of secondary structure is discussed, along with new evidence for tertiary interactions. These include a loop E motif in domain III and a long-range pairing interaction that links domain II to domain V. The results of our work provide mechanistic insight into key functional elements in the cloverleaf and IRES, thereby establishing a base of structural information from which to interpret experiments with CVB3 and other picornaviruses.

An Integrated Conceptual Model of Quality of Life for Older Adults Based on a Synthesis of the Literature

Abstract: Quality of life is fast becoming a standard of measure of long-term care and gerontological service outcomes. Although the issue of quality of life has been of increasing interest in the field of aging, there has been little agreement as to the clarity and definition of the concept and how to measure it, especially as it relates to older adults. Presented here is a comprehensive, integrated model of quality of life that was developed by synthesizing existing constructs within the literature into six major life domains—(1) social well-being, (2) physical well-being, (3) psychological well-being, (4) cognitive well-being, (5) spiritual well-being, and (6) environmental well-being. Consistent with a general systems framework, this holistic model expands the predominant Health-Related Quality of Life constructs to incorporate non-physical aspects of well-being. Each of these domains was broken down into several dimensions in an effort to operationalize the concept of quality of life so that it can have some common standard of useful measurement. These major life domains and indicators are important factors in determining the perceptions of quality of life of older adults. Understanding what constitutes quality of life and how to measure it comprehensively has significant implications for social policy and practice in the field of aging.