10 resultados para Multiplicity of voices

em DigitalCommons@The Texas Medical Center


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Cancer is the second leading cause of death in the United States. With the advent of new technologies, changes in health care delivery, and multiplicity of provider types that patients must see, cancer care management has become increasingly complex. The availability of cancer health information has been shown to help cancer patients cope with the management and effects of their cancers. As a result, more cancer patients are using the internet to find resources that can aid in decision-making and recovery. ^ The Health Information National Trends Survey (HINTS) is a nationally representative survey designed to collect information about the experiences of cancer and non-cancer adults with health information sources. The HINTS survey focused on both conventional sources as well as newer technologies, particularly the internet. This study is a descriptive analysis of the HINTS 2003 and HINTS 2005 survey data. The purpose of the research is to explore the general trends in health information seeking and use by US adults, and especially by cancer patients. ^ From 2003 to 2005, internet use for various health-related activities appears to have increased among adults with and without cancer. Differences were found between the groups in the general trust in information media, particularly the internet. Non-cancer respondents tended to have greater trust in information media than cancer respondents. ^ The latter portion of this work examined characteristics of HINTS respondents that were thought to be relevant to how much trust individuals placed in the internet as a source of health information. Trust in health information from the internet was significantly greater among younger adults, higher-earning households, internet users, online seekers of health or cancer information, and those who found online cancer information useful. ^

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Environmental exposures during sensitive windows of development can reprogram normal physiological responses and alter disease susceptibility later in life in a process known as developmental reprogramming. We have shown that neonatal exposure to the xenoestrogen diethylstilbestrol (DES) can developmentally reprogram the reproductive tract in genetically susceptible Eker rats giving rise to complete penetrance of uterine leiomyoma. Based on this, we hypothesized that xenoestrogens, including genistein (GEN) and bisphenol A (BPA), reprogram estrogen-responsive gene expression in the myometrium and promote the development of uterine leiomyoma. We proposed the mechanism that is responsible for the developmental reprogramming of gene expression was through estrogen (E2)/ xenoestrogen inducedrapid ER signaling, which modifies the histone methyltransferase Enhancer of Zeste homolog 2 (EZH2) via activation of the PI3K/AKT pathway. We further hypothesized that there is a xenostrogen-specific effect on this pathway altering patterns of histone modification, DNA methylation and gene expression. In addition to our novel finding that E2/DES-induced phosphorylation of EZH2 by AKT reduces the levels of H3K27me3 in vitro and in vivo, this work demonstrates in vivo that a brief neonatal exposure to GEN, in contrast to BPA, activates the PI3K/AKT pathway to regulate EZH2 and decreases H3K27me3 levels in the neonatal uterus. Given that H3K27me3 is a repressive mark that has been shown to result in DNA methylation and gene silencing we investigated the methylation of developmentally reprogrammed genes. In support of this evidence, we show that neonatal DES exposure in comparison to VEH, leads to hypomethylation of the promoter of a developmentally reprogrammed gene, Gria2, that become hyper-responsive to estrogen in the adult myometrium indicating vi that DES exposure alter gene expression via chromatin remodeling and loss of DNA methylation. In the adult uterus, GEN and BPA exposure developmentally reprogrammed expression of estrogen-responsive genes in a manner opposite of one another, correlating with our previous data. Furthermore, the ability of GEN and BPA to developmental reprogram gene expression correlated with tumor incidence and multiplicity. These data show that xenoestrogens have unique effects on the activation of non-genomic signaling in the developing uterus that promotes epigenetic and genetic alterations, which are predictive of developmental reprogramming and correlate with their ability to modulate hormone-dependent tumor development.

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Withdrawal reflexes of the mollusk Aplysia exhibit sensitization, a simple form of long-term memory (LTM). Sensitization is due, in part, to long-term facilitation (LTF) of sensorimotor neuron synapses. LTF is induced by the modulatory actions of serotonin (5-HT). Pettigrew et al. developed a computational model of the nonlinear intracellular signaling and gene network that underlies the induction of 5-HT-induced LTF. The model simulated empirical observations that repeated applications of 5-HT induce persistent activation of protein kinase A (PKA) and that this persistent activation requires a suprathreshold exposure of 5-HT. This study extends the analysis of the Pettigrew model by applying bifurcation analysis, singularity theory, and numerical simulation. Using singularity theory, classification diagrams of parameter space were constructed, identifying regions with qualitatively different steady-state behaviors. The graphical representation of these regions illustrates the robustness of these regions to changes in model parameters. Because persistent protein kinase A (PKA) activity correlates with Aplysia LTM, the analysis focuses on a positive feedback loop in the model that tends to maintain PKA activity. In this loop, PKA phosphorylates a transcription factor (TF-1), thereby increasing the expression of an ubiquitin hydrolase (Ap-Uch). Ap-Uch then acts to increase PKA activity, closing the loop. This positive feedback loop manifests multiple, coexisting steady states, or multiplicity, which provides a mechanism for a bistable switch in PKA activity. After the removal of 5-HT, the PKA activity either returns to its basal level (reversible switch) or remains at a high level (irreversible switch). Such an irreversible switch might be a mechanism that contributes to the persistence of LTM. The classification diagrams also identify parameters and processes that might be manipulated, perhaps pharmacologically, to enhance the induction of memory. Rational drug design, to affect complex processes such as memory formation, can benefit from this type of analysis.

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E2F1 is a multi-faceted protein that has roles in a number of important cellular processes including cell cycle regulation, apoptosis, proliferation, and the DNA damage response (DDR). Moreover, E2F1 has opposing roles in tumor development, acting as either a tumor suppressor or an oncogene depending on the context. In human cancer, E2F1 is often deregulated through aberrations in the Rb-p16INK4a-cyclin D1 pathway. In these studies we examined three mechanisms by which E2F1 might mediate its tumor suppressive properties: p21-induced senescence, miRNAs, and the DNA damage response. We found that E2F1 acts as a tumor suppressor in response to ras activation through a non-apoptotic mechanism requiring ARF and p53, but not p21. However, p21-loss inhibited two-stage chemical carcinogenesis in FVB mice. In response to E2F1 overexpression, we found that 22 miRNAs are differentially regulated in mouse epidermis, including let-7a, let-7c, and miR-301. Additionally, regulation of miR-301 involves binding of E2F1 to its promoter. Finally, our data indicate a role for E2F1 at sites of DNA damage requiring E2F1’s phosphorylation at serine 31 which may involve DNA repair. Further, this role in the DDR may affect tumor aggressiveness and multiplicity. In all, we have explored three mechanisms for E2F1-induced tumor suppression and identified E2F1’s role in the DNA damage response as a likely contributor to this phenomenon.

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Mammalian genomes encode at least 15 distinct DNA polymerases, functioning as specialists in DNA replication, DNA repair, recombination, or bypass of DNA damage. Although the DNA polymerase zeta (polzeta) catalytic subunit REV3L is important in defense against genotoxins, little is known of its biological function. This is because REV3L is essential during embryogenesis, unlike other translesion DNA polymerases. Outstanding questions include whether any adult cells are viable in the absence of polzeta and whether polzeta status influences tumorigenesis. REV3L-deficient cells have properties that could influence the development of neoplasia in opposing ways: markedly reduced damage-induced point mutagenesis and extensive chromosome instability. To answer these questions, Rev3L was conditionally deleted from tissues of adult mice using MMTV-Cre. Loss of REV3L was tolerated in epithelial tissues but not in the hematopoietic lineage. Thymic lymphomas in Tp53(-/-) Rev3L conditional mice occurred with decreased latency and higher incidence. The lymphomas were populated predominantly by Rev3L-null T cells, showing that loss of Rev3L can promote tumorigenesis. Remarkably, the tumors were frequently oligoclonal, consistent with accelerated genetic changes in the absence of Rev3L. Mammary tumors could also arise from Rev3L-deleted cells in both Tp53(+/+) and Tp53(+/-) backgrounds. Mammary tumors in Tp53(+/-) mice deleting Rev3L formed months earlier than mammary tumors in Tp53(+/-) control mice. Prominent preneoplastic changes in glandular tissue adjacent to these tumors occurred only in mice deleting Rev3L and were associated with increased tumor multiplicity. Polzeta is the only specialized DNA polymerase yet identified that inhibits spontaneous tumor development.

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This qualitative study conducted semi-structured, multi-session focus groups and interviews with twenty-seven participants to explore in-depth, participant constructs of child discipline and punishment methods and reasons for the continuing support for corporal punishment of U.S. children. The research assumed that parents want to parent well and utilized the strengths perspective as the instrument to listen to participants' voices. Narratives revealed that participants were thoughtful about discipline and parenting strategies and viewed their parent role as a serious commitment. Non-violent discipline strategies, particularly communication, were often used. However, parents generally framed use of physical punishment as “when children need spanking” versus articulating the view that corporal punishment is a choice. Parents were unfamiliar with risks associated with physical punishment and only three parents, as a result of their foster parent training, had ever heard, “Do not spank.” Participants enumerated services and recommendations that would support and inform their own parenting, as well as, benefit children and the eighty percent of women and men in the United States who become mothers and fathers. Recommendations included: creation of a national campaign to build on parent strengths and the intentionality of effective parenting; child development education and increased public awareness of positive discipline methods; parenting supports, including respite and venues for dialogue and discourse about parenting. Recommendations are intended to inform child welfare practice and policy, particularly child abuse prevention. Creating, funding, and implementing a national campaign as described would challenge the dominant child welfare paradigm from one currently perceived as punitive and focused on parents' deficits to a strengths-based paradigm that provides supports and assistance to parents and children.

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There is a growing consensus among professionals working with parents and children, and advocates for child rights, that a ban on the use of corporal punishment (CP) in raising children is justified in accordance with the United Nations Convention on the Rights of the Child (CRC, 1989). However, this is an issue which seems to polarize people and opponents of banning CP have attacked the scientific literature and made dire predictions of adverse consequences if parents are not allowed to use CP. The problem is that so much attention has been focused on the “to spank or not to spank” issue, the developmental benefits for children and parents stemming from positive parenting have been largely ignored. There is increasing evidence that public health approaches to increasing parenting support reduces coercive parenting practices. Breshears' study represents an effort to gain a clearer understanding of the reasons many parents continue to support CP and draws on innovative qualitative methods to argue that parents’ views about CP are important and must be taken into account in planning intervention programs.

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Epidemiological studies have led to the hypothesis that major risk factors for developing diseases such as hypertension, cardiovascular disease and adult-onset diabetes are established during development. This developmental programming hypothesis proposes that exposure to an adverse stimulus or insult at critical, sensitive periods of development can induce permanent alterations in normal physiological processes that lead to increased disease risk later in life. For cancer, inheritance of a tumor suppressor gene defect confers a high relative risk for disease development. However, these defects are rarely 100% penetrant. Traditionally, gene-environment interactions are thought to contribute to the penetrance of tumor suppressor gene defects by facilitating or inhibiting the acquisition of additional somatic mutations required for tumorigenesis. The studies presented herein identify developmental programming as a distinctive type of gene-environment interaction that can enhance the penetrance of a tumor suppressor gene defect in adult life. Using rats predisposed to uterine leiomyoma due to a germ-line defect in one allele of the tuberous sclerosis complex 2 (Tsc-2) tumor suppressor gene, these studies show that early-life exposure to the xenoestrogen, diethylstilbestrol (DES), during development of the uterus increased tumor incidence, multiplicity and size in genetically predisposed animals, but failed to induce tumors in wild-type rats. Uterine leiomyomas are ovarian-hormone dependent tumors that develop from the uterine myometrium. DES exposure was shown to developmentally program the myometrium, causing increased expression of estrogen-responsive genes prior to the onset of tumors. Loss of function of the normal Tsc-2 allele remained the rate-limiting event for tumorigenesis; however, tumors that developed in exposed animals displayed an enhanced proliferative response to ovarian steroid hormones relative to tumors that developed in unexposed animals. Furthermore, the studies presented herein identify developmental periods during which target tissues are maximally susceptible to developmental programming. These data suggest that exposure to environmental factors during critical periods of development can permanently alter normal physiological tissue responses and thus lead to increased disease risk in genetically susceptible individuals. ^

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IκB kinase α (IKKα) is one kinase subunit of the IKK complex that is responsible for NF-κB activation. Previous studies have shown that IKKα determines mouse keratinocyte terminal differentiation independent of the NF-κB pathway. Accumulating evidence suggests that IKKα functions as a tumor suppressor in skin carcinogenesis; however, the downstream pathways mediating this function are largely unknown. By using primary cultured keratinocytes, we found that Ikkα-/- cells developed aneuploidy and underwent spontaneous immortalization and transformation while wild type cells underwent terminal differentiation in the same culture condition. Using proteomic analysis we identified nucleophosmin (NPM), a centrosome duplication regulator, as an IKKα substrate. We further demonstrated that IKKα interacted with NPM and colocalized with NPM on the centrosome, suggesting that NPM is a physiological substrate of IKKα. Loss of IKKα reduced centrosome-bound NPM and promoted abnormal centrosome amplification, which contributed to aneuploidy development. Detailed analysis revealed that ablation of IKKα target site serine-125 of NPM induced destabilization of NPM hexamers, disrupted NPM association with centrosomes, and resulted in abnormal centrosome amplification. Re-introduction of IKKα rescued the defect in Ikkα-/- keratinocytes. Thus, IKKα is required for maintaining proper centrosome duplication by phosphorylating NPM. ^ UV is the major etiological agent for human skin cancer and UV-induced mouse skin carcinogenesis is one of the most relevant experimental models for human skin carcinogenesis. Thus, we further evaluated IKKα function in UV-induced skin carcinogenesis in Ikkα+/- mice. We demonstrated that IKKα is also critical in UV skin carcinogenesis, as evidenced by increased tumor multiplicity and reduced tumor latency in Ikkα+/- mice after chronic UVB treatment. Reduced expression of IKKα decreased UV-induced apoptosis and promoted accumulation of P53 mutations in the epidermis. This indicates that IKKα is critical for UV-induced apoptosis in vivo and thus prevents mutation accumulation that is important for tumor development. ^ Together, these findings uncover previously unknown in vivo functions of IKKα in centrosome duplication and apoptosis, thus providing a possible mechanism of how loss of IKKα may contribute to skin carcinogenesis. ^

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Background: Receipt of early prenatal care, care during the first three months of pregnancy, is the standard in the United States. Sixty percent of non-Hispanic Black women who had a live birth in the Sunnyside community of Houston did not obtain early prenatal care in 2009. ^ This study's aims were to: 1) Describe the barriers to obtaining early prenatal care in non-Hispanic Black women who live in the Sunnyside community of Houston; and, 2) Describe the actions that could encourage non-Hispanic Black women who live in the Sunnyside Community to obtain early prenatal care. The goal was to provide information to organizations that promote early prenatal care use in non-Hispanic Black women in Harris County that may aid in developing interventions. ^ Methods: The Participatory Learning for Action rapid assessment qualitative method was used in a group setting to answer the research questions on behalf of women in the community. Women who participated in the group sessions also participated in an in-depth interview. Key informants who work in the community with pregnant women, or promote the use of prenatal care services, were also interviewed. An inductive analysis of the data was conducted to identify common themes that address the study's aims. ^ Results: Aim 1: Group participants identified fear of the reaction from family and/or the baby's daddy and shame, not having insurance or money, and lack of knowledge of the pregnancy and resources as the top three barriers to early prenatal care for women in the community. Aim 2: Group participants stated that to help women to overcome these barriers, communication, awareness and support; help, resources and services; and information and early education are needed. Participant in-depth interviewees echoed the themes of fear of the reaction from family and/or the baby's daddy and not knowing of the pregnancy. Key informants mentioned these themes as well, though not at the same priority level. Participants and key informants also mentioned similar themes for helping women to overcome barriers to early prenatal care. ^ Conclusion: A comprehensive approach is needed to improve early prenatal care use in the Sunnyside community. Education efforts must include all members of the community, young and old, to promote support for pregnant women. Community members must be a part of the process for developing education campaigns. Engaging the community builds a relationship with organizations that serve the community, which may promote use of the organizations' services, and build trust with the community. All efforts must be ongoing so that women and men of all ages in the community understand the importance of prenatal care and support women obtaining care early in the pregnancy.^