18 research outputs found

    The Mbd1-Atf7ip-Setdb1 pathway contributes to the maintenance of X chromosome inactivation.

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    BackgroundX chromosome inactivation (XCI) is a developmental program of heterochromatin formation that initiates during early female mammalian embryonic development and is maintained through a lifetime of cell divisions in somatic cells. Despite identification of the crucial long non-coding RNA Xist and involvement of specific chromatin modifiers in the establishment and maintenance of the heterochromatin of the inactive X chromosome (Xi), interference with known pathways only partially reactivates the Xi once silencing has been established. Here, we studied ATF7IP (MCAF1), a protein previously characterized to coordinate DNA methylation and histone H3K9 methylation through interactions with the methyl-DNA binding protein MBD1 and the histone H3K9 methyltransferase SETDB1, as a candidate maintenance factor of the Xi.ResultsWe found that siRNA-mediated knockdown of Atf7ip in mouse embryonic fibroblasts (MEFs) induces the activation of silenced reporter genes on the Xi in a low number of cells. Additional inhibition of two pathways known to contribute to Xi maintenance, DNA methylation and Xist RNA coating of the X chromosome, strongly increased the number of cells expressing Xi-linked genes upon Atf7ip knockdown. Despite its functional importance in Xi maintenance, ATF7IP does not accumulate on the Xi in MEFs or differentiating mouse embryonic stem cells. However, we found that depletion of two known repressive biochemical interactors of ATF7IP, MBD1 and SETDB1, but not of other unrelated H3K9 methyltransferases, also induces the activation of an Xi-linked reporter in MEFs.ConclusionsTogether, these data indicate that Atf7ip acts in a synergistic fashion with DNA methylation and Xist RNA to maintain the silent state of the Xi in somatic cells, and that Mbd1 and Setdb1, similar to Atf7ip, play a functional role in Xi silencing. We therefore propose that ATF7IP links DNA methylation on the Xi to SETDB1-mediated H3K9 trimethylation via its interaction with MBD1, and that this function is a crucial feature of the stable silencing of the Xi in female mammalian cells

    A Retrospective Descriptive Study of Stat TPN Orders in the Neonatal Intensive Care Unit

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    BACKGROUND: Total parenteral nutrition (TPN) is used in the Neonatal Intensive Care Unit (NICU) to meet metabolic demand and provide growth. To prevent harm from critical laboratory abnormalities, stat TPNs can be ordered urgently to change the content of infusing TPN. Each stat order breaks the daily cycle and often leads to additional stat orders. Limited supplies of ingredients brought focus on our liberal stat TPN policy and how to reduce the number of stat TPNs safely. The purpose of this project was to evaluate biochemical abnormalities associated with stat TPNs and identify leverage points to reduce stat TPNs in NICU patients. METHODS: Data from 1/1/10 to 6/30/10 were abstracted from Meditech, NeoData, and patient charts for NICU stat TPN orders. Demographics, laboratory results (sodium, potassium, calcium, and glucose), and key variables were gathered and critical laboratory values were identified. RESULTS: A total of 112 patients had evaluable orders for 255 stat TPNs. Mean gestation was 31 weeks (SD = 5) and birth weight was 1.744 kg (SD = 0.993). Seven (3%) were never infused. Twenty (12.6%) of first stat TPNs were from patients taking nothing by mouth. Eighty-eight of first stat TPNs had no critical labs (55% of initial stat TPNs). Of follow-up stat orders, 43% (38/89) followed unnecessary initial stat TPNs. Of the 55 abnormalities that generated the initial stat TPNs, 44 (80%) corrected. CONCLUSIONS: Fifty-two percent of stat TPNs could not be justified. For situations that were justified, 20% of laboratory abnormalities from initial stat TPNs were not corrected. These data provide an opportunity to reduce unnecessary costs and save limited resources

    The Role of Spirituality in Conceptualizations of Health Maintenance and Healthy Aging Among Latin American Immigrants.

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    ObjectivesWe aimed to investigate ways in which spirituality was conceptualized in relationship to maintaining brain health and healthy aging in a cohort of older adults who immigrated to the United States from diverse regions of Latin America, in order to ultimately develop culturally-tailored brain health promotion approaches.DesignWe conducted a qualitative study using semi-structured interviews.SettingParticipants were recruited from community centers and by a memory care center at a large academic medical center.ParticipantsWe interviewed 30 Spanish-speaking immigrants over age 60. Questions addressed perspectives about the brain, aging, and dementia. Interviews were coded for themes.MeasurementsThematic analysis was used to analyze participants' responses.ResultsWe identified 5 themes: (1) expressing gratitude to God for mental and physical health, (2) putting the onus of life and death in God's hands, (3) using church as a place to socialize and build community as an approach to leading a healthy lifestyle, (4) using prayer as nourishment for the soul and the brain, and (5) gaining inner-peace and calm, and thus maintaining a healthy life, due to a connection with God.ConclusionThe incorporation of customized spiritual interventions may be a mechanism by which to increase the effectiveness of brain health promotion efforts
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