7,136 research outputs found
RAS mutation status predicts survival and patterns of recurrence in patients undergoing hepatectomy for colorectal liver metastases.
ObjectiveTo determine the impact of RAS mutation status on survival and patterns of recurrence in patients undergoing curative resection of colorectal liver metastases (CLM) after preoperative modern chemotherapy.BackgroundRAS mutation has been reported to be associated with aggressive tumor biology. However, the effect of RAS mutation on survival and patterns of recurrence after resection of CLM remains unclear.MethodsSomatic mutations were analyzed using mass spectroscopy in 193 patients who underwent single-regimen modern chemotherapy before resection of CLM. The relationship between RAS mutation status and survival outcomes was investigated.ResultsDetected somatic mutations included RAS (KRAS/NRAS) in 34 (18%), PIK3CA in 13 (7%), and BRAF in 2 (1%) patients. At a median follow-up of 33 months, 3-year overall survival (OS) rates were 81% in patients with wild-type versus 52.2% in patients with mutant RAS (P = 0.002); 3-year recurrence-free survival (RFS) rates were 33.5% with wild-type versus 13.5% with mutant RAS (P = 0.001). Liver and lung recurrences were observed in 89 and 83 patients, respectively. Patients with RAS mutation had a lower 3-year lung RFS rate (34.6% vs 59.3%, P < 0.001) but not a lower 3-year liver RFS rate (43.8% vs 50.2%, P = 0.181). In multivariate analyses, RAS mutation predicted worse OS [hazard ratio (HR) = 2.3, P = 0.002), overall RFS (HR = 1.9, P = 0.005), and lung RFS (HR = 2.0, P = 0.01), but not liver RFS (P = 0.181).ConclusionsRAS mutation predicts early lung recurrence and worse survival after curative resection of CLM. This information may be used to individualize systemic and local tumor-directed therapies and follow-up strategies
A map of the day-night contrast of the extrasolar planet HD 189733b
"Hot Jupiter" extrasolar planets are expected to be tidally locked because
they are close (<0.05 astronomical units, where 1 AU is the average Sun-Earth
distance) to their parent stars, resulting in permanent daysides and
nightsides. By observing systems where the planet and star periodically eclipse
each other, several groups have been able to estimate the temperatures of the
daysides of these planets. A key question is whether the atmosphere is able to
transport the energy incident upon the dayside to the nightside, which will
determine the temperature at different points on the planet's surface. Here we
report observations of HD 189733, the closest of these eclipsing planetary
systems, over half an orbital period, from which we can construct a 'map' of
the distribution of temperatures. We detected the increase in brightness as the
dayside of the planet rotated into view. We estimate a minimum brightness
temperature of 973 +/- 33 K and a maximum brightness temperature of 1212 +/- 11
K at a wavelength of 8 microns, indicating that energy from the irradiated
dayside is efficiently redistributed throughout the atmosphere, in contrast to
a recent claim for another hot Jupiter. Our data indicate that the peak
hemisphere-integrated brightness occurs 166 degrees before opposition,
corresponding to a hot spot shifted east of the substellar point. The secondary
eclipse (when the planet moves behind the star) occurs 120 +/- 24 s later than
predicted, which may indicate a slightly eccentric orbit.Comment: To appear in the May 10 2007 issue of Nature, 10 pages, 2 black and
white figures, 1 colo
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Adaptation of the DEMQOL-Proxy for routine use in care homes: a cross sectional study of the reliability and validity of DEMQOL-CH
Objective: To investigate the routine use of a measure of quality of life (QoL) in care homes and assess its psychometric properties when used by care staff
Design: A cross-sectional two-phase study. Setting and participants: Data were collected from care staff in seven care homes in East Sussex, England.
Method: Phase 1: The ability of care staff from two care homes to use the DEMQOL-Proxy without interviewer-administration was assessed using agreement analysis between a selfand interviewer-administered version of the instrument. Based on these findings, DEMQOLProxy was adapted into a new version, DEMQOL-CH, for use as a self-administered instrument in care homes. We assessed agreement between the new DEMQOL-CH and DEMQOL-Proxy to ensure DEMQOL-CH was used correctly. Phase 2: A preliminary assessment of the psychometric properties of DEMQOL-CH when used routinely was completed in a further five care homes.
Results: Phase 1: Nineteen care staff from two care homes completed QoL measurements for residents. Systematic error was identified when staff self-completed the DEMQOL-Proxy without an interviewer. We modified the DEMQOL-Proxy to create DEMQOL-CH; this reduced the error, producing a version that could be used more accurately by care staff. Phase 2: Eleven care staff from five care homes rated resident QoL routinely. DEMQOL-CH showed acceptable psychometric properties with satisfactory reliability and validity and a clear factor structure.
Conclusions: The research presents positive preliminary data on the acceptability, feasibility and performance of routine QoL measurement in care homes using an adapted version of DEMQOL-Proxy, the DEMQOL-CH. Results provide evidence to support the concept that routine measurement of QoL may be possible in care homes. Research is needed to refine and test the methodology and instrument further, and to explore the potential for benefits to residents, staff, and care homes in larger and more representative populations
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Psychometric properties and feasibility of use of dementia specific quality of life instruments for use in care settings: a systematic review
Background: Over 400,000 people live in care home settings in the UK. One way of understanding and improving the quality of care provided is by measuring and understanding the quality of life (QoL) of those living in care homes. This review aimed to identify and examine the psychometric properties including feasibility of use of dementia-speciļ¬c QoL measures developed or validated for use in care settings. Design: Systematic review.
Methods: Instruments were identiļ¬ed using four electronic databases (PubMed, PsycINFO, Web of Science, and CINAHL) and lateral search techniques. Searches were conducted in January 2017. Studies which reported on the development and/or validation of dementia speciļ¬c QoL instruments for use in care settings written in English were eligible for inclusion. The methodological quality of the studies was assessed using the COSMIN checklist. Feasibility was assessed using a checklist developed speciļ¬cally for the review.
Results: Six hundred and sixteen articles were identiļ¬ed in the initial search. After de-duplication, screening and further lateral searches were performed, 25 studies reporting on 9 dementia-speciļ¬c QoL instruments for use in care home settings were included in the review. Limited evidence was available on the psychometric properties of many instruments identiļ¬ed. Higher-quality instruments were not easily accessible or had low feasibility of use.
Conclusions: Few high-quality instruments of QoL validated for use in care home settings are readily or freely available. This review highlights the need to develop a well-validated measure of QoL for use within care homes that is also feasible and accessible
HOPS 383: An Outbursting Class 0 Protostar in Orion
We report the dramatic mid-infrared brightening between 2004 and 2006 of HOPS
383, a deeply embedded protostar adjacent to NGC 1977 in Orion. By 2008, the
source became a factor of 35 brighter at 24 microns with a brightness increase
also apparent at 4.5 microns. The outburst is also detected in the
submillimeter by comparing APEX/SABOCA to SCUBA data, and a scattered-light
nebula appeared in NEWFIRM K_s imaging. The post-outburst spectral energy
distribution indicates a Class 0 source with a dense envelope and a luminosity
between 6 and 14 L_sun. Post-outburst time-series mid- and far-infrared
photometry shows no long-term fading and variability at the 18% level between
2009 and 2012. HOPS 383 is the first outbursting Class 0 object discovered,
pointing to the importance of episodic accretion at early stages in the star
formation process. Its dramatic rise and lack of fading over a six-year period
hint that it may be similar to FU Ori outbursts, although the luminosity
appears to be significantly smaller than the canonical luminosities of such
objects.Comment: Accepted by ApJ Letters, 6 pages, 4 figures; v2 has an updated email
address for the lead autho
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