229 research outputs found

    Single-Molecule Analysis of the Human Telomerase RNA·Dyskerin Interaction and the Effect of Dyskeratosis Congenita Mutations†

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    It has been proposed that human telomerase RNA (hTR) interacts with dyskerin, prior to assembly of the telomerase holoenzyme. The direct interaction of dyskerin and hTR has not been demonstrated and is an experimentally challenging research problem because of difficulties in expressing and purifying dyskerin in quantities that are useful for biophysical analysis. By orthogonally labeling dyskerin and hTR, we have been able to employ single-molecule two-color coincidence detection (TCCD) to observe directly the formation of a dyskerin·hTR complex. By systematic deletion of hTR subdomains, we have gained insights into the RNA sites required for interaction with dyskerin. We then investigated mutated forms of hTR and dyskerin that are associated with dyskeratosis congenita (DC), on the basis of clinical genetics studies, for their effects on the dyskerin·hTR interaction. Dyskerin mutations associated with X-linked DC resulted in significant impairment of the dyskerin·hTR interaction, whereas mutations in hTR associated with autosomal dominant (AD) DC did not affect the interaction. We propose that disruption of the dyskerin·hTR interaction may contribute to X-linked DC

    Germline heterozygous DDX41 variants in a subset of familial myelodysplasia and acute myeloid leukemia

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    The Brazilian National Council for Scientific and Technological Development), Bloodwise, Children with Cancer and MRC (Medical Research Council, UK)

    Telomere and telomerase in stem cells

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    Telomeres, guanine-rich tandem DNA repeats of the chromosomal end, provide chromosomal stability, and cellular replication causes their loss. In somatic cells, the activity of telomerase, a reverse transcriptase that can elongate telomeric repeats, is usually diminished after birth so that the telomere length is gradually shortened with cell divisions, and triggers cellular senescence. In embryonic stem cells, telomerase is activated and maintains telomere length and cellular immortality; however, the level of telomerase activity is low or absent in the majority of stem cells regardless of their proliferative capacity. Thus, even in stem cells, except for embryonal stem cells and cancer stem cells, telomere shortening occurs during replicative ageing, possibly at a slower rate than that in normal somatic cells. Recently, the importance of telomere maintenance in human stem cells has been highlighted by studies on dyskeratosis congenital, which is a genetic disorder in the human telomerase component. The regulation of telomere length and telomerase activity is a complex and dynamic process that is tightly linked to cell cycle regulation in human stem cells. Here we review the role of telomeres and telomerase in the function and capacity of the human stem cells

    Viscoelastic haemostatic assay augmented protocols for major trauma haemorrhage (ITACTIC): a randomized, controlled trial

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    Purpose: Contemporary trauma resuscitation prioritizes control of bleeding and uses major haemorrhage protocols (MHPs) to prevent and treat coagulopathy. We aimed to determine whether augmenting MHPs with Viscoelastic Haemostatic Assays (VHA) would improve outcomes compared to Conventional Coagulation Tests (CCTs). Methods: This was a multi-centre, randomized controlled trial comparing outcomes in trauma patients who received empiric MHPs, augmented by either VHA or CCT-guided interventions. Primary outcome was the proportion of subjects who, at 24 h after injury, were alive and free of massive transfusion (10 or more red cell transfusions). Secondary outcomes included 28-day mortality. Pre-specified subgroups included patients with severe traumatic brain injury (TBI). Results: Of 396 patients in the intention to treat analysis, 201 were allocated to VHA and 195 to CCT-guided therapy. At 24 h, there was no difference in the proportion of patients who were alive and free of massive transfusion (VHA: 67%, CCT: 64%, OR 1.15, 95% CI 0.76–1.73). 28-day mortality was not different overall (VHA: 25%, CCT: 28%, OR 0.84, 95% CI 0.54–1.31), nor were there differences in other secondary outcomes or serious adverse events. In pre-specified subgroups, there were no differences in primary outcomes. In the pre-specified subgroup of 74 patients with TBI, 64% were alive and free of massive transfusion at 24 h compared to 46% in the CCT arm (OR 2.12, 95% CI 0.84–5.34). Conclusion: There was no difference in overall outcomes between VHA- and CCT-augmented-major haemorrhage protocols

    Familial aggregation of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia with solid tumors and myeloid malignancies.

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links field.Lymphoplasmacytic lymphoma (LPL)/Waldenström macroglobulinemia (WM) is a B-cell disorder resulting from the accumulation, predominantly in the bone marrow, of clonally related lymphoplasmacytic cells. LPL/WM is a very rare disease, with an incidence rate of 3-4 cases per million people per year.Currently, the causes of LPL/WM are poorly understood; however, there are emerging data to support a role for immune-related factors in the pathogenesis of LPL/WM. In addition, data show that genetic factors are of importance in the etiology of LPL/WM. In this paper, we will review the current knowledge about familiality of LPL/WM and provide novel data on solid tumors and myeloid malignancies in first-degree relatives of LPL/WM patients.Swedish Cancer Society Stockholm County Council Karolinska Institutet Foundations National Institutes of Health, National Cancer Institute Roch

    Popular music and school music education: Chinese students' preferences and dilemmas in Shanghai, China

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    This empirical study investigates Chinese students’ popular music preferences in daily life and to what extent and in what ways they prefer learning popular music in school in Shanghai, China. Data were drawn from questionnaires completed by 1,730 secondary students (aged 12–17) and interviews with 60 students from 10 secondary schools, between September and October, 2011. Findings from these efforts were supplemented by and triangulated with data from interviews with 18 music teachers and school leaders. Findings revealed the cultural diversification and rational consumption of popular music by Chinese students in and out of school, as well as the cultural dilemmas those students confront due to their preferences for popular (Chinese and non-Chinese) and classical music in the school music curriculum. These findings can be interpreted as indicating that music and music education in formal or informal settings are complex cultural constructs that can be reinvented through the intertwined interplay of different actors concerned with the selection of music elements in a multileveled, multicultural world.postprin
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