990 resultados para Powe, Alex


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Background: Beta-blockers have potential antiangiogenic and antimigratory activity. Studies have demonstrated a survival benefit in patients with malignant melanoma treated with beta-blockers.

Objectives: To investigate the association between postdiagnostic beta-blocker usage and risk of melanoma-specific mortality in a population-based cohort of patients with malignant melanoma.

Methods: Patients with incident malignant melanoma diagnosed between 1998 and 2010 were identified within the U.K. Clinical Practice Research Datalink and confirmed using cancer registry data. Patients with malignant melanoma with a melanoma-specific death (cases) recorded by the Office of National Statistics were matched on year of diagnosis, age and sex to four malignant melanoma controls (who lived at least as long after diagnosis as their matched case). A nested case–control approach was used to investigate the association between postdiagnostic beta-blocker usage and melanoma-specific death and all-cause mortality. Conditional logistic regression was applied to generate odds ratios (ORs) and 95% confidence intervals (CIs) for beta-blocker use determined from general practitioner prescribing.

Results: Beta-blocker medications were prescribed after malignant melanoma diagnosis to 20·2% of 242 patients who died from malignant melanoma (cases) and 20·3% of 886 matched controls. Consequently, there was no association between beta-blocker use postdiagnosis and cancer-specific death (OR 0·99, 95% CI 0·68–1·42), which did not markedly alter after adjustment for confounders including stage (OR 0·87, 95% CI 0·56–1·34). No significant associations were detected for individual beta-blocker types, by defined daily doses of use or for all-cause mortality.

Conclusions: Contrary to some previous studies, beta-blocker use after malignant melanoma diagnosis was not associated with reduced risk of death from melanoma in this U.K. population-based study.

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Background: To investigate the association between post-diagnostic beta-blocker usage and risk of cancer-specific mortality in a large population-based cohort of female breast cancer patients.

Methods: A nested case-control study was conducted within a cohort of breast cancer patients identified from cancer registries in England(using the National Cancer Data repository) and diagnosed between 1998 and 2007. Patients who had a breast cancer-specific death(ascertained from Office of National Statistics death registration data) were each matched to four alive controls by year and age at diagnosis. Prescription data for these patients were available through the Clinical Practice Research Datalink. Conditional logistic regression models were used to investigate the association between breast cancer-specific death and beta-blocker usage.

Results: Post-diagnostic use of beta-blockers was identified in 18.9% of 1435 breast cancer-specific deaths and 19.4% of their 5697 matched controls,indicating little evidence of association between beta-blocker use and breast cancer-specific mortality [odds ratio (OR) = 0.97,95% confidence interval (CI) 0.83, 1.13]. There was also little evidence of an association when analyses were restricted to cardio non-selective beta-blockers (OR = 0.90, 95% CI 0.69, 1.17). Similar results were observed in analyses of drug dosage frequency and duration, and beta-blocker type.

Conclusions: In this large UK population-based cohort of breast cancer patients,there was little evidence of an association between post-diagnostic beta-blocker usage and breast cancer progression. Further studies which include information on tumour receptor status are warranted to determine whether response to beta-blockers varies by tumour subtypes.

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Purpose: Aspirin use is associated with reduced risk of, and death from, prostate cancer. Our aim was to determine whether low-dose aspirin use after a prostate cancer diagnosis was associated with reduced prostate cancer-specific mortality.

Methods: A cohort of newly diagnosed prostate cancer patients (1998–2006) was identified in the UK Clinical Practice Research Datalink (confirmed by cancer registry linkage). A nested case–control analysis was conducted using conditional logistic regression to compare aspirin usage in cases (prostate cancer deaths) with up to three controls (matched by age and year of diagnosis).

Results: Post-diagnostic low-dose aspirin use was identified in 52 % of 1,184 prostate cancer-specific deaths and 39 % of 3,531 matched controls (unadjusted OR 1.51, 95 % CI 1.19, 1.90; p < 0.001). After adjustment for confounders including treatment and comorbidities, this association was attenuated (adjusted OR 1.02 95 % CI 0.78, 1.34; p = 0.86). Adjustment for estrogen therapy accounted for the majority of this attenuation. There was also no evidence of dose–response association after adjustments. Compared with no use, patients with 1–11 prescriptions and 12 or more prescriptions had adjusted ORs of 1.07 (95 % CI 0.78, 1.47; p = 0.66) and 0.97 (95 % CI 0.69, 1.37; p = 0.88), respectively. There was no evidence of a protective association between low-dose aspirin use in the year prior to diagnosis and prostate cancer-specific mortality (adjusted OR 1.04 95 % CI 0.89, 1.22; p = 0.60).

Conclusion: We found no evidence of an association between low-dose aspirin use before or after diagnosis and risk of prostate cancer-specific mortality, after potential confounders were accounted for, in UK prostate cancer patients.

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The most active binary PtSn catalyst for direct ethanol fuel cell applications has been studied at 20 oC and 60 oC, using variable temperature electrochemical in-situ FTIR. In comparison with Pt, binary PtSn inhibits ethanol dissociation to CO(a), but promotes partial oxidation to acetaldehyde and acetic acid. Increasing the temperature from 20 oC to 60 oC facilitates both ethanol dissociation to CO(a) and their further oxidation to CO2, leading to an increased selectivity towards CO2; however, acetaldehyde and acetic acid are still the main products. Potential-dependent phase diagrams for surface oxidants of OH(a) formation on Pt(111), Pt(211) and Sn modified Pt(111) and Pt(211) surfaces have been determined using density functional theory (DFT) calculations. It is shown that Sn promotes the formation of OH(a) with a lower onset potential on the Pt(111) surface, whereas an increase in the onset potential is found on modification of the (211) surface. In addition, Sn inhibits the Pt(211) step edge with respect to ethanol C-C bond breaking compared with that found on the pure Pt, which reduces the formation of CO(a). Sn was also found to facilitate ethanol dehydrogenation and partial oxidation to acetaldehyde and acetic acid which, combined with the more facile OH(a) formation on the Pt(111) surface, gives us a clear understanding of the experimentally determined results. This combined electrochemical in-situ FTIR and DFT study, provides, for the first time, an insight into the long-term puzzling features of the high activity but low CO2 production found on binary PtSn ethanol fuel cell catalysts.

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Rationale: Increasing epithelial repair and regeneration may hasten resolution of lung injury in patients with the Acute Respiratory Distress Syndrome (ARDS). In animal models of ARDS, Keratinocyte Growth Factor (KGF) reduces injury and increases epithelial proliferation and repair. The effect of KGF in the human alveolus is unknown.

Objectives: To test whether KGF can attenuate alveolar injury in a human model of ARDS.

Methods: Volunteers were randomized to intravenous KGF (60 μg/kg) or placebo for 3 days, before inhaling 50μg lipopolysaccharide. Six hours later, subjects underwent bronchoalveolar lavage (BAL) to quantify markers of alveolar inflammation and cell-specific injury.

Measurements and Main Results: KGF did not alter leukocyte infiltration or markers of permeability in response to LPS. KGF increased BAL concentrations of Surfactant Protein D (SP-D), MMP-9, IL-1Ra, GM-CSF and CRP. In vitro, BAL fluid from KGF-treated subjects (KGF BAL) inhibited pulmonary fibroblast proliferation, but increased alveolar epithelial proliferation. Active MMP-9 increased alveolar epithelial wound repair. Finally, BAL from the KGF pre-treated group enhanced macrophage phagocytic uptake of apoptotic epithelial cells and bacteria compared with BAL from the placebo-treated group. This effect was blocked by inhibiting activation of the GM-CSF receptor.

Conclusions: KGF treatment increases BAL SP-D, a marker of type II alveolar epithelial cell proliferation in a human model of ALI. Additionally KGF increases alveolar concentrations of the anti-inflammatory cytokine IL-1Ra, and mediators that drive epithelial repair (MMP-9) and enhance macrophage clearance of dead cells and bacteria (GM-CSF).

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Background: Recent laboratory and epidemiological evidence suggests that beta-blockers could inhibit prostate cancer progression. Methods: We investigated the effect of beta-blockers on prostate cancer-specific mortality in a cohort of prostate cancer patients. Prostate cancer patients diagnosed between 1998 and 2006 were identified from the UK Clinical Practice Research Database and confirmed by cancer registries. Patients were followed up to 2011 with deaths identified by the Office of National Statistics. A nested case-control analysis compared patients dying from prostate cancer (cases) with up to three controls alive at the time of their death, matched by age and year of diagnosis. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using conditional logistic regression. Results: Post-diagnostic beta-blocker use was identified in 25% of 1184 prostate cancer-specific deaths and 26% of 3531 matched controls. There was little evidence (P=0.40) of a reduction in the risk of cancer-specific death in beta-blocker users compared with non-users (OR=0.94 95% CI 0.81, 1.09). Similar results were observed after adjustments for confounders, in analyses by beta-blocker frequency, duration, type and for all-cause mortality. Conclusions: Beta-blocker usage after diagnosis was not associated with cancer-specific or all-cause mortality in prostate cancer patients in this large UK study.

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Coronary artery disease (CAD) is the commonest cause of death. Here, we report an association analysis in 63,746 CAD cases and 130,681 controls identifying 15 loci reaching genome-wide significance, taking the number of susceptibility loci for CAD to 46, and a further 104 independent variants (r(2)

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INTRODUCTION: Recent observational studies indicate that post-diagnostic use of aspirin in breast cancer patients may protect against cancer progression perhaps by inhibiting cyclooxygenase-2 dependent mechanisms. Evidence also supports a crucial role for interactions between tumour cells and circulating platelets in cancer growth and dissemination, therefore, use of low-dose aspirin may reduce the risk of death from cancer in breast cancer patients.

METHODS: A cohort of newly diagnosed breast cancer patients (1998 to 2006) were identified in the UK Clinical Practice Research Datalink (and confirmed by cancer registry linkage). Cancer-specific deaths were identified up to 2011 from Office for National Statistics mortality data. A nested case-control analysis was conducted using conditional logistic regression to compare post-diagnostic aspirin exposure using General Practice prescription data in 1,435 cases (breast cancer deaths) with 5,697 controls (matched by age and year of diagnosis).

RESULTS: After breast cancer diagnosis, 18.3% of cancer-specific deaths and 18.5% of matched controls received at least one prescription for low-dose aspirin, corresponding to an odds ratio (OR) of 0.98 (95% CI 0.83, 1.15). Adjustment for potential confounders (including stage and grade) had little impact on this estimate. No dose response relationship was observed when the number of tablets was investigated and no associations were seen when analyses were stratified by receipt of prescriptions for aspirin in the pre-diagnostic period, by stage at diagnosis or by receipt of prescriptions for hormone therapy.

CONCLUSIONS: Overall, in this large population-based cohort of breast cancer patients, there was little evidence of an association between receipt of post-diagnostic prescriptions for low-dose aspirin and breast cancer-specific death. However, information was not available on medication compliance or over-the-counter use of aspirin, which may have contributed to the null findings.

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Accurate models of cement and interface fatigue are essential if computationally assessing risk of aseptic loosening of cemented joint replacements is to become clinically relevant. A series of approaches will be presented that attempt to model several aspects of bone cement fatigue relevant to predicting cemented joint replacement failure. Failure models for homogeneous (bulk) bone cement and its interface with implant and host tissue are reviewed. Variability introduced by porosity and interaction between fatigue and creep are also considered. Finally, some current and potential future developments are discussed.