1,534 research outputs found
An RNA interference screen for identifying downstream effectors of the p53 and pRB tumour suppressor pathways involved in senescence
Background: Cellular senescence is an irreversible cell cycle arrest that normal cells undergo in response to progressive shortening of telomeres, changes in telomeric structure, oncogene activation or oxidative stress and acts as an important tumour suppressor mechanism.Results: To identify the downstream effectors of the p53-p21 and p16-pRB tumour suppressor pathways crucial for mediating entry into senescence, we have carried out a loss-of-function RNA interference screen in conditionally immortalised human fibroblasts that can be induced to rapidly undergo senescence, whereas in primary cultures senescence is stochastic and occurs asynchronously. These cells are immortal but undergo a rapid irreversible arrest upon activation of the p53-p21 and p16-pRB pathways that can be readily bypassed upon their inactivation. The primary screen identified 112 known genes including p53 and another 29 shRNAmirs targetting as yet unidentified loci. Comparison of these known targets with genes known to be up-regulated upon senescence in these cells, by micro-array expression profiling, identified 4 common genes TMEM9B, ATXN10, LAYN and LTBP2/3. Direct silencing of these common genes, using lentiviral shRNAmirs, bypassed senescence in the conditionally immortalised cells.Conclusion: The senescence bypass screen identified TMEM9B, ATXN10, LAYN and LTBP2/3 as novel downstream effectors of the p53-p21 and p16-pRB tumour suppressor pathways. Although none of them has previously been linked to cellular senescence, TMEM9B has been suggested to be an upstream activator of NF-kappa B signalling which has been found to have a causal role in promoting senescence. Future studies will focus on determining on how many of the other primary hits also have a casual role in senescence and what is the mechanism of action
Hybrid silicon nanostructures with conductive ligands and their microscopic conductivities
Silicon nanoparticles (SiNPs) functionalized with conjugated molecules promise a potential pathway to generate a new category of thermoelectric materials. While the thermoelectric performance of materials based on phenyl-acetylene capped SiNPs has been proven, their low conductivity is still a problem for their general application. A muon study of phenyl-acetylene capped SiNPs has been recently carried out using the HiFi spectrometer at the Rutherford Appleton Laboratory, measuring the ALC spectra as a function of temperature. The results show a reduction in the measured line width of the resonance above room temperature, suggesting an activated behaviour for this system. This study shows that the muon study could be a powerful method to investigate microscopic conductivity of hybrid thermoelectric materials
Characteristics of outdoor falls among older people: A qualitative study
Background Falls are a major threat to older people’s health and wellbeing. Approximately half of falls occur in outdoor environments but little is known about the circumstances in which they occur. We conducted a qualitative study to explore older people’s experiences of outdoor falls to develop understanding of how they may be prevented. Methods We conducted nine focus groups across the UK (England, Wales, and Scotland). Our sample was from urban and rural settings and different environmental landscapes. Participants were aged 65+ and had at least one outdoor fall in the past year. We analysed the data using framework and content analyses. Results Forty-four adults aged 65 – 92 took part and reported their experience of 88 outdoor falls. Outdoor falls occurred in a variety of contexts, though reports suggested the following scenarios may have been more frequent: when crossing a road, in a familiar area, when bystanders were around, and with an unreported or unknown attribution. Most frequently, falls resulted in either minor or moderate injury, feeling embarrassed at the time of the fall, and anxiety about falling again. Ten falls resulted in fracture, but no strong pattern emerged in regard to the contexts of these falls. Anxiety about falling again appeared more prevalent among those that fell in urban settings and who made more visits into their neighbourhood in a typical week. Conclusions This exploratory study has highlighted several aspects of the outdoor environment that may represent risk factors for outdoor falls and associated fear of falling. Health professionals are recommended to consider outdoor environments as well as the home setting when working to prevent falls and increase mobility among older people
Combinatorial CRISPR-Cas9 screens for de novo mapping of genetic interactions.
We developed a systematic approach to map human genetic networks by combinatorial CRISPR-Cas9 perturbations coupled to robust analysis of growth kinetics. We targeted all pairs of 73 cancer genes with dual guide RNAs in three cell lines, comprising 141,912 tests of interaction. Numerous therapeutically relevant interactions were identified, and these patterns replicated with combinatorial drugs at 75% precision. From these results, we anticipate that cellular context will be critical to synthetic-lethal therapies
Translational genomics of ovarian clear cell carcinoma.
Ovarian clear cell carcinomas (OCCC) are rare aggressive, chemo-resistant tumours comprising approximately 13% of all epithelial ovarian cancers, which have distinct clinical and molecular features, when compared to other gynaecological malignancies. At present, there are no specific licensed targeted therapies for OCCC, although a number of candidate targets have been identified. This review focuses on recent knowledge underpinning our understanding of the pathogenesis of OCCC including direct and synthetic-lethal therapeutic strategies in particular focussing on ARID1A deficiency. We also discuss current targeted clinical trials and immunotherapeutic approaches
A route to new cancer therapies:the FA pathway is essential in BRCA1- or BRCA2-deficient cells
Mutations in the BRCA1 and BRCA2 genes strongly predispose carriers to breast and ovarian cancers. Two new studies reveal that FANCD2, a key component of the Fanconi anemia pathway, is essential for the survival of cells with BRCA1 or BRCA2 mutations. These findings pave the way for new 'synthetic lethal' strategies to kill BRCA-mutated cancers.<br/
Comparison of embedded and added motor imagery training in patients after stroke: Study protocol of a randomised controlled pilot trial using a mixed methods approach
Copyright @ 2009 Schuster et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Two different approaches have been adopted when applying motor imagery (MI) to stroke patients. MI can be conducted either added to conventional physiotherapy or integrated within therapy sessions. The proposed study aims to compare the efficacy of embedded MI to an added MI intervention. Evidence from pilot studies reported in the literature suggests that both approaches can improve performance of a complex motor skill involving whole body movements, however, it remains to be demonstrated, which is the more effective one.Methods/Design: A single blinded, randomised controlled trial (RCT) with a pre-post intervention design will be carried out. The study design includes two experimental groups and a control group (CG). Both experimental groups (EG1, EG2) will receive physical practice of a clinical relevant motor task ('Going down, laying on the floor, and getting up again') over a two week intervention period: EG1 with embedded MI training, EG2 with MI training added after physiotherapy. The CG will receive standard physiotherapy intervention and an additional control intervention not related to MI.The primary study outcome is the time difference to perform the task from pre to post-intervention. Secondary outcomes include level of help needed, stages of motor task completion, degree of motor impairment, balance ability, fear of falling measure, motivation score, and motor imagery ability score. Four data collection points are proposed: twice during baseline phase, once following the intervention period, and once after a two week follow up. A nested qualitative part should add an important insight into patients' experience and attitudes towards MI. Semi-structured interviews of six to ten patients, who participate in the RCT, will be conducted to investigate patients' previous experience with MI and their expectations towards the MI intervention in the study. Patients will be interviewed prior and after the intervention period.Discussion: Results will determine whether embedded MI is superior to added MI. Findings of the semi-structured interviews will help to integrate patient's expectations of MI interventions in the design of research studies to improve practical applicability using MI as an adjunct therapy technique
Extragalactic Results from the Infrared Space Observatory
More than a decade ago the IRAS satellite opened the realm of external
galaxies for studies in the 10 to 100 micron band and discovered emission from
tens of thousands of normal and active galaxies. With the 1995-1998 mission of
the Infrared Space Observatory the next major steps in extragalactic infrared
astronomy became possible: detailed imaging, spectroscopy and
spectro-photometry of many galaxies detected by IRAS, as well as deep surveys
in the mid- and far- IR. The spectroscopic data reveal a wealth of detail about
the nature of the energy source(s) and about the physical conditions in
galaxies. ISO's surveys for the first time explore the infrared emission of
distant, high-redshift galaxies. ISO's main theme in extragalactic astronomy is
the role of star formation in the activity and evolution of galaxies.Comment: 106 pages, including 17 figures. Ann.Rev.Astron.Astrophys. (in
press), a gzip'd pdf file (667kB) is also available at
http://www.mpe.mpg.de/www_ir/preprint/annrev2000.pdf.g
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