290 research outputs found
A complex regional intervention to implement advance care planning in one town's nursing homes: Protocol of a controlled inter-regional study
<p>Abstract</p> <p>Background</p> <p>Advance Care Planning (ACP) is an emerging strategy to ensure that well-reflected, meaningful and clearly documented treatment preferences are available and respected when critical decisions about life-sustaining treatment need to be made for patients unable to consent. In Germany, recent legislation confirms that advance directives (AD) have to be followed if they apply to the medical situation, but implementation of ACP has not yet been described.</p> <p>Methods/Design</p> <p>In a longitudinal controlled study, we compare 1 intervention region (4 nursing homes [n/hs], altogether 421 residents) with 2 control regions (10 n/hs, altogether 985 residents). Inclusion went from 01.02.09 to 30.06.09, observation lasted until 30.06.10. Primary endpoint is the prevalence of ADs at follow-up, 17 (12) months after the first (last) possible inclusion. Secondary endpoints compare relevance and validity of ADs, process quality, the rate of life-sustaining interventions and, in deceased residents, location of death and intensity of treatment before death. The regional multifaceted intervention on the basis of the US program Respecting Choices<sup>® </sup>comprises training of n/h staff as facilitators, training of General Practitioners, education of hospital and ambulance staff, and development of eligible tools, including Physician Orders for Life-Sustaining Treatment in case of Emergency (POLST-E).</p> <p><it>Participation data: </it>Of 1406 residents reported to live in the 14 n/hs plus an estimated turnover of 176 residents until the last possible inclusion date, 645 (41%) were willing to participate. Response rates were 38% in the intervention region and 42% in the control region. Non-responder analysis shows an equal distribution of sex and age but a bias towards dependency on nursing care in the responder group. <it>Outcome analysis </it>of this study will become available in the course of 2011.</p> <p>Discussion</p> <p>Implementing an ACP program for the n/hs and related health care providers of a region requires a complex community intervention with the effect of nothing less than a cultural shift in this health care sector. This study is to our knowledge the first to develop a strategy for regional implementation of ACP, and to evaluate its feasibility in a controlled design.</p> <p>Trial Registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN99887420">ISRCTN99887420</a></p
Bias and temperature dependence of the 0.7 conductance anomaly in Quantum Point Contacts
The 0.7 (2e^2/h) conductance anomaly is studied in strongly confined, etched
GaAs/GaAlAs quantum point contacts, by measuring the differential conductance
as a function of source-drain and gate bias as well as a function of
temperature. We investigate in detail how, for a given gate voltage, the
differential conductance depends on the finite bias voltage and find a
so-called self-gating effect, which we correct for. The 0.7 anomaly at zero
bias is found to evolve smoothly into a conductance plateau at 0.85 (2e^2/h) at
finite bias. Varying the gate voltage the transition between the 1.0 and the
0.85 (2e^2/h) plateaus occurs for definite bias voltages, which defines a gate
voltage dependent energy difference . This energy difference is
compared with the activation temperature T_a extracted from the experimentally
observed activated behavior of the 0.7 anomaly at low bias. We find \Delta =
k_B T_a which lends support to the idea that the conductance anomaly is due to
transmission through two conduction channels, of which the one with its subband
edge \Delta below the chemical potential becomes thermally depopulated as the
temperature is increased.Comment: 9 pages (RevTex) with 9 figures (some in low resolution
Effect of Vitamin D Supplementation on Markers of Vascular Function: A Systematic Review and Individual Participant Meta- Analysis
Background-—Low 25-hydroxyvitamin D levels are associated with an increased risk of cardiovascular events, but the effect of
vitamin D supplementation on markers of vascular function associated with major adverse cardiovascular events is unclear.
Methods and Results-—We conducted a systematic review and individual participant meta-analysis to examine the effect of vitamin D
supplementation on flow-mediated dilatation of the brachial artery, pulse wave velocity, augmentation index, central blood pressure,
microvascular function, and reactive hyperemia index. MEDLINE, CINAHL, EMBASE, Cochrane Central Register of Controlled Trials, and
http://www.ClinicalTrials.gov were searched until the end of 2016 without language restrictions. Placebo-controlled randomized trials
of at least4 weeks duration were included. Individual participant data were sought from investigators on included trials. Trial-level metaanalysis
was performed using random-effects models; individual participant meta-analyses used a 2-stage analytic strategy, examining
effects in prespecified subgroups. 31trials (2751 participants) were included; 29 trials (2641participants) contributed data to trial-level
meta-analysis, and24trials (2051 participants) contributed to individual-participant analyses. VitaminD3daily dose equivalents ranged
from 900 to 5000 IU; duration was 4 weeks to12 months. Trial-level meta-analysis showed no significant effect of supplementation on
macrovascularmeasures(flow-mediateddilatation,0.37%[95%confidenceinterval, 0.23to0.97]; carotid-femoralpulsewavevelocity,
0.00 m/s [95% confidence interval, 0.36 to 0.37]); similar results were obtained from individual participant data. Microvascular
function showed a modest improvement in trial-level data only. No consistent benefit was observed in subgroup analyses or between
different vitamin D analogues.
Conclusions-—Vitamin D supplementation had no significant effect on most markers of vascular function in this analysis
Imaging in the time of NFD/NSF: do we have to change our routines concerning renal insufficiency?
To date there are potential chronology-based but not conclusive reasons to believe that at least some of the gadolinium complexes play a causative role in the pathophysiology of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). Still, the exact pathogenesis and the risk for patients is unclear beside the obvious connection to moderate to severe renal insufficiency. So far, MR imaging with Gd-enhancement was regarded as the safest imaging modality in these patients—the recent development creates tremendous uncertainty in the MR-community. Nevertheless, one should remember that, despite the over 200 cases of NSF and about 100 with proven involvement of Gd3+, the vast majority of over 200 million patients exposed to gadolinium since the 1980s have tolerated these agents well. Importantly, NSF is a rare disease and does not appear to occur in patients without renal impairment. Many patients and researchers have undergone MR investigations with Gd exposure in the past. For those, it is essential to know about the safety of the agents at normal renal function. We can hope that pharmacoepidemiological and preclinical studies will allow us to better understand the pathophysiology and role of the various MR contrast agents in the near future
Elevated Peripheral Neutrophils and Matrix Metalloproteinase 9 as Biomarkers of Functional Outcome Following Subarachnoid Hemorrhage
There is growing evidence supporting the role of inflammation in early brain injury and cerebral vasospasm following subarachnoid hemorrhage (SAH). Matrix metalloproteinases (MMPs) are released by inflammatory cells and can mediate early brain injury via disruption of the extracellular matrix and mediate vasospasm by cleaving endothelin-1 into vasoactive fragments. We hypothesize that inflammation marked by neutrophil elevation and MMP-9 release in human SAH is associated with vasospasm and with poor clinical outcome. We enrolled consecutive SAH subjects (N = 55), banked serial blood and cerebrospinal fluid (CSF) samples, and evaluated their 3-month modified Rankin scores (mRS). Vasospasm was defined as >50% vessel caliber reduction on angiography 6–8 days post-SAH. A poor outcome was defined as mRS > 2. We compared blood leukocyte and neutrophil counts during post-SAH days 0–14 with respect to vasospasm and 3-month outcome. In a subset of SAH subjects (N = 35), we compared blood and CSF MMP-9 by enzyme-linked immunosorbent assay (ELISA) on post-SAH days 0–1, 2–3, 4–5, 6–8, and 10–14 with respect to vasospasm and to 3-month outcome. Persistent elevation of blood leukocyte (p = 0.0003) and neutrophil (p = 0.0002) counts during post-SAH days 0–14 are independently associated with vasospasm after adjustment for major confounders. In the same time period, blood neutrophil count (post-SAH days 2–3, p = 0.018), blood MMP-9 (post-SAH days 4–5, p = 0.045), and CSF MMP-9 (post-SAH days 2–3, p = 0.05) are associated with poor 3-month SAH clinical outcome. Neutrophil count correlates with blood MMP-9 (post-SAH days 6–8, R = 0.39; p = 0.055; post-SAH days 10–14, R = 0.79; p < 0.0001), and blood MMP-9 correlates with CSF MMP-9 (post-SAH days 4–5, R = 0.72; p = 0.0002). Elevation of CSF MMP-9 during post-SAH days 0–14 is associated with poor 3-month outcome (p = 0.0078). Neither CSF nor blood MMP-9 correlates with vasospasm. Early rise in blood neutrophil count and blood and CSF MMP-9 are associated with poor 3-month SAH clinical outcome. In blood, neutrophil count correlates with MMP-9 levels, suggesting that neutrophils may be an important source of blood MMP-9 early in SAH. Similarly, CSF and blood MMP-9 correlate positively early in the course of SAH, suggesting that blood may be an important source of CSF MMP-9. Blood and CSF MMP-9 are associated with clinical outcome but not with vasospasm, suggesting that MMP-9 may mediate brain injury independent of vasospasm in SAH. Future in vitro studies are needed to investigate the role of MMP-9 in SAH-related brain injury. Larger clinical studies are needed to validate blood and CSF MMP-9 as potential biomarkers for SAH outcome
Metabolic Effects of Krill Oil are Essentially Similar to Those of Fish Oil but at Lower Dose of EPA and DHA, in Healthy Volunteers
The purpose of the present study is to investigate the effects of krill oil and fish oil on serum lipids and markers of oxidative stress and inflammation and to evaluate if different molecular forms, triacylglycerol and phospholipids, of omega-3 polyunsaturated fatty acids (PUFAs) influence the plasma level of EPA and DHA differently. One hundred thirteen subjects with normal or slightly elevated total blood cholesterol and/or triglyceride levels were randomized into three groups and given either six capsules of krill oil (N = 36; 3.0 g/day, EPA + DHA = 543 mg) or three capsules of fish oil (N = 40; 1.8 g/day, EPA + DHA = 864 mg) daily for 7 weeks. A third group did not receive any supplementation and served as controls (N = 37). A significant increase in plasma EPA, DHA, and DPA was observed in the subjects supplemented with n-3 PUFAs as compared with the controls, but there were no significant differences in the changes in any of the n-3 PUFAs between the fish oil and the krill oil groups. No statistically significant differences in changes in any of the serum lipids or the markers of oxidative stress and inflammation between the study groups were observed. Krill oil and fish oil thus represent comparable dietary sources of n-3 PUFAs, even if the EPA + DHA dose in the krill oil was 62.8% of that in the fish oil
Image quality and diagnostic accuracy of unenhanced SSFP MR angiography compared with conventional contrast-enhanced MR angiography for the assessment of thoracic aortic diseases
The purpose of this study was to determine the image quality and diagnostic accuracy of three-dimensional (3D) unenhanced steady state free precession (SSFP) magnetic resonance angiography (MRA) for the evaluation of thoracic aortic diseases.
Fifty consecutive patients with known or suspected thoracic aortic disease underwent free-breathing ECG-gated unenhanced SSFP MRA with non-selective radiofrequency excitation and contrast-enhanced (CE) MRA of the thorax at 1.5 T. Two readers independently evaluated the two datasets for image quality in the aortic root, ascending aorta, aortic arch, descending aorta, and origins of supra-aortic arteries, and for abnormal findings. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined for both datasets. Sensitivity, specificity, and diagnostic accuracy of unenhanced SSFP MRA for the diagnosis of aortic abnormalities were determined.
Abnormal aortic findings, including aneurysm (n = 47), coarctation (n = 14), dissection (n = 12), aortic graft (n = 6), intramural hematoma (n = 11), mural thrombus in the aortic arch (n = 1), and penetrating aortic ulcer (n = 9), were confidently detected on both datasets. Sensitivity, specificity, and diagnostic accuracy of SSFP MRA for the detection of aortic disease were 100% with CE-MRA serving as a reference standard. Image quality of the aortic root was significantly higher on SSFP MRA (P < 0.001) with no significant difference for other aortic segments (P > 0.05). SNR and CNR values were higher for all segments on SSFP MRA (P < 0.01).
Our results suggest that free-breathing navigator-gated 3D SSFP MRA with non-selective radiofrequency excitation is a promising technique that provides high image quality and diagnostic accuracy for the assessment of thoracic aortic disease without the need for intravenous contrast material
Research cardiac magnetic resonance imaging in end stage renal disease - incidence, significance and implications of unexpected incidental findings
Objectives:
Left ventricular mass (LVM) at cardiac magnetic resonance imaging (CMR) is a frequent end point in clinical trials in nephrology. Trial participants with end stage renal disease (ESRD) may have a greater frequency of incidental findings (IF). We retrospectively investigated prevalence of IF in previous research CMR and reviewed their subsequent impact on participants.
Methods:
Between 2002 and 2006, 161 ESRD patients underwent CMR in a transplant assessment study. Images were used to assess LV mass and function. In the current study a radiologist reviewed the scans for IF. Review of patient records determined the subsequent clinical significance of IF.
Results:
There were 150 IF in 95 study participants. Eighty-four (56 %) were new diagnoses. One hundred and two were non-cardiac. Fifteen were suspicious of malignancy. There was a clinically significant IF for 14.9 % of the participants. In six cases earlier identification of an IF may have improved quality of life or survival.
Conclusions:
Without radiology support clinically important IF may be missed on CMR. Patients undergoing CMR in trials should be counselled about the frequency and implications of IF. Patients with ESRD have a higher prevalence of IF than reported in other populations. Nephrology studies require mechanisms for radiologist reporting and strategies for dealing with IF
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