434 research outputs found
Factors That Promote H3 Chromatin Integrity during Transcription Prevent Promiscuous Deposition of CENP-A(Cnp1) in Fission Yeast
Specialized chromatin containing CENP-A nucleosomes instead of H3 nucleosomes is found at all centromeres. However, the mechanisms that specify the locations at which CENP-A chromatin is assembled remain elusive in organisms with regional, epigenetically regulated centromeres. It is known that normal centromeric DNA is transcribed in several systems including the fission yeast, Schizosaccharomyces pombe. Here, we show that factors which preserve stable histone H3 chromatin during transcription also play a role in preventing promiscuous CENP-A(Cnp1) deposition in fission yeast. Mutations in the histone chaperone FACT impair the maintenance of H3 chromatin on transcribed regions and promote widespread CENP-A(Cnp1) incorporation at non-centromeric sites. FACT has little or no effect on CENP-A(Cnp1) assembly at endogenous centromeres where CENP-A(Cnp1) is normally assembled. In contrast, Clr6 complex II (Clr6-CII; equivalent to Rpd3S) histone deacetylase function has a more subtle impact on the stability of transcribed H3 chromatin and acts to prevent the ectopic accumulation of CENP-A(Cnp1) at specific loci, including subtelomeric regions, where CENP-A(Cnp1) is preferentially assembled. Moreover, defective Clr6-CII function allows the de novo assembly of CENP-A(Cnp1) chromatin on centromeric DNA, bypassing the normal requirement for heterochromatin. Thus, our analyses show that alterations in the process of chromatin assembly during transcription can destabilize H3 nucleosomes and thereby allow CENP-A(Cnp1) to assemble in its place. We propose that normal centromeres provide a specific chromatin context that limits reassembly of H3 chromatin during transcription and thereby promotes the establishment of CENP-A(Cnp1) chromatin and associated kinetochores. These findings have important implications for genetic and epigenetic processes involved in centromere specification
“You Probably Won’t Notice Any Symptoms”: Blood Pressure in Pregnancy—Discourses of Contested Expertise in an Era of Self-Care and Responsibilization
Pregnancy is not a disease or illness, but requires clinical surveillance as life-threatening complications can develop. Preeclampsia, one such potentially serious complication, puts both mother and baby at risk. Self-monitoring blood pressure in the general population is well established, and its potential in pregnancy is currently being explored. In the context of self-monitoring, the information and guidance given to women regarding hypertension, and the literature they themselves seek out during pregnancy, are vital to perceptions of disease risk and subsequent responses to, and management of, any symptoms. Drawing on online, offline, official, and unofficial sources of information, discourses are examined to provide analysis of how self-responsibilization is reflected in contemporary information, advice, and guidance drawn from multiple sources. A paradox emerges between the paternalistic and lay discourses that seek to challenge and regain control. Findings are discussed in the context of Foucault’s governmentality and medical power
Pregnancy outcomes in female childhood and adolescent cancer survivors: a linked cancer-birth registry analysis
Objective: To compare birth outcomes among childhood and adolescent female cancer survivors who subsequently bear children, relative to those of women without cancer history.
Design: Retrospective cohort study.
Setting: 4 U.S. regions.
Participants: Cancer registries identified girls <20 years, diagnosed with cancer 1973-2000. Linked birth records identified first live births after diagnosis (n=1898). Comparison subjects were selected from birth records (n=14278). Cervical/genital tract cancer cases were analyzed separately.
Main Exposure: Cancer diagnosis <20 years.
Outcome Measures: Infant low birth weight, preterm delivery, sex ratio, malformations, mortality, delivery method; maternal diabetes, anemia, preeclampsia.
Results: Childhood cancer survivors’ infants were more likely to be preterm (relative risk [RR] 1.54, 95% CI 1.30-1.83) and weigh <2500 g (RR 1.31, 95% CI 1.10-1.57). For cervical/genital cancer patients’ offspring, estimates were 1.33 (95% CI 1.13, 1.56), and 1.29 (95% CI 1.10-1.53), respectively. There were no increased risks of malformations, infant death, or altered sex ratio, suggesting no increased germ cell mutagenicity. In exploratory analysis, bone cancer survivors had an increased risk of diabetes (RR 4.92, 95% CI 1.60-15.13), and anemia was more common among brain tumor survivors (RR 3.05, 95% CI 1.16-7.98) and childhood cancer survivors with initial treatment of chemotherapy only (RR 2.45, 95% CI 1.16-5.17).
Conclusions: Infants of female childhood and adolescent cancer patients were not at increased risk of malformations or death. Increased occurrence of preterm delivery and low birth weight suggest close monitoring is warranted. Increased diabetes and anemia among sub-groups have not been reported, suggesting areas for study
Reproductive outcomes in male childhood cancer survivors: a linked cancer-birth registry analysis
OBJECTIVE: Compare the risk of reproductive and infant outcomes between male childhood cancer survivors and a population-based comparison group.
DESIGN: Retrospective cohort study.
SETTING: 4 U.S. regions.
PARTICIPANTS: Cancer registries identified males <20 years old diagnosed with cancer 1973-2000. Linked birth certificates identified first subsequent live offspring (n=470). Comparison subjects were identified from remaining birth certificates, frequency-matched on year and age at fatherhood, and race/ethnicity (n=4150).
MAIN EXPOSURE: Cancer diagnosis prior to age 20.
OUTCOME MEASURES: Pregnancy and infant outcomes identified from birth certificates.
RESULTS: Compared with infants born to unaffected males, offspring of cancer survivors had a borderline risk of birth weight <2500 g (RR 1.43, 95% CI 0.99-2.05), with risk associated most strongly with younger age of cancer diagnosis and exposure to any chemotherapy (RR 1.96, 95% CI 1.22-3.17) or radiotherapy (RR 1.95, 95% CI 1.14-3.35). However, they were not at risk of being born prematurely, small for gestational age, having malformations or an altered male:female sex ratio. Overall, female partners of male survivors were not more likely to have maternal complications recorded on birth records versus the comparison group. However, preeclampsia was associated with some cancers, especially central nervous system tumors (RR 3.36, 95% CI 1.63-6.90). CONCLUSIONS: Most pregnancies resulting in live births among partners of male childhood cancer survivors were not at significantly greater risk of complications versus comparison subjects. The possibility of a paternal component affected by prior cancer history influencing predisposition towards some adverse perinatal outcomes merits further investigation
The Lantern Vol. 52, No. 1, Fall 1985
• Nudes • Orion • Fragments of an Epic • Sunrise • The Planting Season • Nursing Home • Hope Chest • Childhood Swing • Relationships • Elroy, Leopold, and Max • Urban Dragon • The Farmer\u27s Wife • A Ballad of Two Lovers • Betrayal • Choices • Letting Go • Emergence of a Butterfly • Poem for Every Man • Friction • Genesis • All\u27s Well • The Willow Tree • White Wasteland • Moe\u27s Happy Christmas • Rare Bird • Carnivalhttps://digitalcommons.ursinus.edu/lantern/1127/thumbnail.jp
“What if There's Something Wrong with Her?”‐How Biomedical Technologies Contribute to Epistemic Injustice in Healthcare
While there is a steadily growing literature on epistemic injustice in healthcare, there are few discussions of the role that biomedical technologies play in harming patients in their capacity as knowers. Through an analysis of newborn and pediatric genetic and genomic sequencing technologies (GSTs), I argue that biomedical technologies can lead to epistemic injustice through two primary pathways: epistemic capture and value partitioning. I close by discussing the larger ethical and political context of critical analyses of GSTs and their broader implications for just and equitable healthcare delivery
Visuospatial Processing Deficits Linked to Posterior Brain Regions in Premanifest and Early Stage Huntington's Disease.
OBJECTIVES: Visuospatial processing deficits have been reported in Huntington's disease (HD). To date, no study has examined associations between visuospatial cognition and posterior brain findings in HD. METHODS: We compared 119 premanifest (55> and 64<10.8 years to expected disease onset) and 104 early symptomatic (59 stage-1 and 45 stage-2) gene carriers, with 110 controls on visual search and mental rotation performance at baseline and 12 months. In the disease groups, we also examined associations between task performance and disease severity, functional capacity and structural brain measures. RESULTS: Cross-sectionally, there were strong differences between all disease groups and controls on visual search, and between diagnosed groups and controls on mental rotation accuracy. Only the premanifest participants close to onset took longer than controls to respond correctly to mental rotation. Visual search negatively correlated with disease burden and motor symptoms in diagnosed individuals, and positively correlated with functional capacity. Mental rotation ("same") was negatively correlated with motor symptoms in stage-2 individuals, and positively correlated with functional capacity. Visual search and mental rotation were associated with parieto-occipital (pre-/cuneus, calcarine, lingual) and temporal (posterior fusiform) volume and cortical thickness. Longitudinally, visual search deteriorated over 12 months in stage-2 individuals, with no evidence of declines in mental rotation. CONCLUSIONS: Our findings provide evidence linking early visuospatial deficits to functioning and posterior cortical dysfunction in HD. The findings are important since large research efforts have focused on fronto-striatal mediated cognitive changes, with little attention given to aspects of cognition outside of these areas. (JINS, 2016, 22, 595-608)
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