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15
result(s) for
"Wallington, David"
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Intermediate clinical endpoints for surrogacy in localised prostate cancer: an aggregate meta-analysis
by
McFarlane, Matthew R
,
Jaworski, Elizabeth M
,
Reichert, Zachery R
in
Aged
,
Biomarkers - analysis
,
Cancer therapies
2021
The international Intermediate Clinical Endpoints in Cancer of the Prostate working group has established metastasis-free survival as a surrogate for overall survival in localised prostate cancer based on the findings of 19 predominantly radiotherapy-based trials. We sought to comprehensively assess aggregate trial-level performance of commonly reported intermediate clinical endpoints across all randomised trials in localised prostate cancer.
For this meta-analysis, we searched PubMed for all trials in localised or biochemically recurrent prostate cancer published between Jan 1, 1970, and Jan 15, 2020. Eligible trials had to be randomised, therapeutic, reporting overall survival and at least one intermediate clinical endpoint, and with a sample size of at least 70 participants. Trials of metastatic disease were excluded. Intermediate clinical endpoints included biochemical failure, local failure, distant metastases, biochemical failure-free survival, progression-free survival, and metastasis-free survival. Candidacy for surrogacy was assessed using the second condition of the meta-analytical approach (ie, correlation of the treatment effect of the intermediate clinical endpoint and overall survival), using R2 weighted by the inverse variance of the log intermediate clinical endpoint hazard ratio. The intermediate clinical endpoint was deemed to be a surrogate for overall survival if R2 was 0·7 or greater.
75 trials (53 631 patients) were included in our analysis. Median follow-up was 9·1 years (IQR 5·7–10·6). Biochemical failure (R2 0·38 [95% CI 0·11–0·64]), biochemical failure-free survival (R2 0·12 [0·0030–0·33]), biochemical failure and clinical failure (R2 0·28 [0·0045–0·65]), and local failure (R2 0·085 [0·00–0·37]) correlated poorly with overall survival. Progression-free survival (R2 0·46 [95% CI 0·22–0·67]) showed moderate correlation with overall survival, and metastasis-free survival (R2 0·78 [0·59–0·89]) correlated strongly.
Intermediate clinical endpoints based on biochemical and local failure did not meet the second condition of the meta-analytical approach and are not surrogate endpoints for overall survival in localised prostate cancer. Our findings validate metastasis-free survival as the only identified surrogate endpoint for overall survival to date.
Prostate Cancer Foundation and National Institutes of Health.
Journal Article
Nanocrystalline Ceramics Close to Stoichiometric MgAl2O4—Overview and Comparison of Traditional Manufacturing Processes with Crystallization Processes at High Pressure
by
Holzheid, Astrid
,
Kulik, Eleonora
,
Durschang, Bernhard
in
Barium oxides
,
Boron oxides
,
Ceramics
2025
Three processes for the production of ceramics close to stoichiometric MgAl2O4 are benchmarked against each other. The traditional ceramic route is based on mostly crystalline starting powder, which is converted into ceramic via shaping and heat treatment (IKTS). The other two processes are based on glasses. Partial or complete crystallization without pressure (ISC) or complete crystallization with pressure (CAU) leads to (glass) ceramics. Spinel powder is mixed with various dopants (BaO, TiO2, CaO and SrO), with the aim to reduce the grain size (IKTS). The doping results in a second, partly interfering phase, and the transmission decreases strongly due to absorption with increasing content of the added oxide. For the glass route without pressure (ISC), it is shown that a network-forming oxide (B2O3, TiO2) is needed to produce the glasses. Compared to the starting glasses, the resultant glass ceramics suffer loss of transparency due to crystallization. Using the levitation furnace, it is possible to produce amorphous glass beads from MgAl2O4 enriched with 25 wt% SiO2 without a container. The nanocrystalline ceramics synthesized from these glasses and the ISC glasses via the high-pressure route (CAU) are moderately transparent to translucent.
Journal Article
Changing Therapeutic Landscape for Melanoma With Multiple Brain Metastases
by
Tarhini, Ahmad
,
Lawson, David H
,
Anker, Christopher J
in
Antimitotic agents
,
Antineoplastic agents
,
Brain
2020
Abstract
Over 90 000 people are expected to be diagnosed with melanoma in the United States this year. The development of brain metastases is particularly difficult to manage. Over the past few years, melanoma patients with multiple unresectable brain metastases for which stereotactic surgery might also not be a viable option have fortunately experienced a dramatic expansion in available management options given improvements made to targeted agents, immunotherapy, and radiotherapy. Whole-brain radiation therapy (WBRT) is a long-standing radiation technique that has become increasingly sophisticated. In this review, we summarize retrospective and prospective studies on individual advances in targeted agents, immunotherapy, and WBRT, highlighting important variables such as overall survival, intracranial progression-free survival, control and response rates, and toxicities. We also discuss the recent integration of these therapies into a multimodality approach, which has shown promise in the clinical setting although toxicities have not been insignificant. Finally, we describe ongoing prospective trials relevant to melanoma with brain metastases, and we conclude with our own thoughts on the optimal approach for these patients.
Journal Article
Simultaneous presentation of thyroid storm and diabetic ketoacidosis in a previously healthy 21-year-old man
by
Schauer, Mark
,
Wallington, David
,
Bauler, Laura D
in
Adult
,
Anti-Arrhythmia Agents - therapeutic use
,
Anti-Inflammatory Agents - therapeutic use
2019
A 21-year-old young man with no history of diabetes or thyroid disease presented to the emergency department with simultaneous thyroid storm and diabetic ketoacidosis. Notable findings on admission were a ventricular rate of 235 beats/min, tachypnoea, tremors, polydipsia and a lack of fever. Due to the unusual constellation of symptoms, diagnosis was only possible after initial laboratory results came back. While the lack of fever is unusual in thyroid storm, diabetic ketoacidosis has previously been reported to suppress fever, and this case supports the occurrence of this phenomenon. This case was highly unusual because the patient had not previously been diagnosed with either type 1 diabetes or Graves’ disease.
Journal Article
Nanocrystalline Ceramics Close to Stoichiometric MgAlsub.2Osub.4—Overview and Comparison of Traditional Manufacturing Processes with Crystallization Processes at High Pressure
by
Holzheid, Astrid
,
Kulik, Eleonora
,
Durschang, Bernhard
in
Ceramic materials
,
Ceramics
,
Powders
2026
Three processes for the production of ceramics close to stoichiometric MgAl[sub.2]O[sub.4] are benchmarked against each other. The traditional ceramic route is based on mostly crystalline starting powder, which is converted into ceramic via shaping and heat treatment (IKTS). The other two processes are based on glasses. Partial or complete crystallization without pressure (ISC) or complete crystallization with pressure (CAU) leads to (glass) ceramics. Spinel powder is mixed with various dopants (BaO, TiO[sub.2], CaO and SrO), with the aim to reduce the grain size (IKTS). The doping results in a second, partly interfering phase, and the transmission decreases strongly due to absorption with increasing content of the added oxide. For the glass route without pressure (ISC), it is shown that a network-forming oxide (B[sub.2]O[sub.3], TiO[sub.2]) is needed to produce the glasses. Compared to the starting glasses, the resultant glass ceramics suffer loss of transparency due to crystallization. Using the levitation furnace, it is possible to produce amorphous glass beads from MgAl[sub.2]O[sub.4] enriched with 25 wt% SiO[sub.2] without a container. The nanocrystalline ceramics synthesized from these glasses and the ISC glasses via the high-pressure route (CAU) are moderately transparent to translucent.
Journal Article
30-day mortality after systemic anticancer treatment for breast and lung cancer in England: a population-based, observational study
by
Bomb, Martine
,
Dodwell, David
,
Smittenaar, Rebecca
in
Aged
,
Antineoplastic Combined Chemotherapy Protocols - therapeutic use
,
Breast cancer
2016
30-day mortality might be a useful indicator of avoidable harm to patients from systemic anticancer treatments, but data for this indicator are limited. The Systemic Anti-Cancer Therapy (SACT) dataset collated by Public Health England allows the assessment of factors affecting 30-day mortality in a national patient population. The aim of this first study based on the SACT dataset was to establish national 30-day mortality benchmarks for breast and lung cancer patients receiving SACT in England, and to start to identify where patient care could be improved.
In this population-based study, we included all women with breast cancer and all men and women with lung cancer residing in England, who were 24 years or older and who started a cycle of SACT in 2014 irrespective of the number of previous treatment cycles or programmes, and irrespective of their position within the disease trajectory. We calculated 30-day mortality after the most recent cycle of SACT for those patients. We did logistic regression analyses, adjusting for relevant factors, to examine whether patient, tumour, or treatment-related factors were associated with the risk of 30-day mortality. For each cancer type and intent, we calculated 30-day mortality rates and patient volume at the hospital trust level, and contrasted these in a funnel plot.
Between Jan 1, and Dec, 31, 2014, we included 23 228 patients with breast cancer and 9634 patients with non-small cell lung cancer (NSCLC) in our regression and trust-level analyses. 30-day mortality increased with age for both patients with breast cancer and patients with NSCLC treated with curative intent, and decreased with age for patients receiving palliative SACT (breast curative: odds ratio [OR] 1·085, 99% CI 1·040–1·132; p<0·0001; NSCLC curative: 1·045, 1·013–1·079; p=0·00033; breast palliative: 0·987, 0·977–0·996; p=0·00034; NSCLC palliative: 0·987, 0·976–0·998; p=0·0015). 30-day mortality was also significantly higher for patients receiving their first reported curative or palliative SACT versus those who received SACT previously (breast palliative: OR 2·326 99% CI 1·634–3·312; p<0·0001; NSCLC curative: 3·371, 1·554–7·316; p<0·0001; NSCLC palliative: 2·667, 2·109–3·373; p<0·0001), and for patients with worse general wellbeing (performance status 2–4) versus those who were generally well (breast curative: 6·057, 1·333–27·513; p=0·0021; breast palliative: 6·241, 4·180–9·319; p<0·0001; NSCLC palliative: 3·384, 2·276–5·032; p<0·0001). We identified trusts with mortality rates in excess of the 95% control limits; this included seven for curative breast cancer, four for palliative breast cancer, five for curative NSCLC, and seven for palliative NSCLC.
Our findings show that several factors affect the risk of early mortality of breast and lung cancer patients in England and that some groups are at a substantially increased risk of 30-day mortality. The identification of hospitals with significantly higher 30-day mortality rates should promote review of clinical decision making in these hospitals. Furthermore, our results highlight the importance of collecting routine data beyond clinical trials to better understand the factors placing patients at higher risk of 30-day mortality, and ultimately improve clinical decision making. Our insights into the factors affecting risk of 30-day mortality will help treating clinicians and their patients predict the balance of harms and benefits associated with SACT.
Public Health England.
Journal Article
Infrared absorption spectra, radiative efficiencies, and global warming potentials of perfluorocarbons: Comparison between experiment and theory
by
Nutt, David R.
,
Wallington, Timothy J.
,
Marston, George
in
Absorption
,
Algorithms
,
Atmosphere
2010
Experimentally and theoretically determined infrared spectra are reported for a series of straight‐chain perfluorocarbons: C2F6, C3F8, C4F10, C5F12, C6F14, and C8F18. Theoretical spectra were determined using both density functional (DFT) and ab initio methods. Radiative efficiencies (REs) were determined using the method of Pinnock et al. (1995) and combined with atmospheric lifetimes from the literature to determine global warming potentials (GWPs). Theoretically determined absorption cross sections were within 10% of experimentally determined values. Despite being much less computationally expensive, DFT calculations were generally found to perform better than ab initio methods. There is a strong wavenumber dependence of radiative forcing in the region of the fundamental C‐F vibration, and small differences in wavelength between band positions determined by theory and experiment have a significant impact on the REs. We apply an empirical correction to the theoretical spectra and then test this correction on a number of branched chain and cyclic perfluoroalkanes. We then compute absorption cross sections, REs, and GWPs for an additional set of perfluoroalkenes.
Journal Article
Tropospheric Ozone Assessment Report: Tropospheric Ozone From 1877 to 2016, Observed Levels, Trends and Uncertainties
by
Cuesta, Juan
,
Zanis, Prodromos
,
Staehelin, Johannes
in
19th century
,
Absorption
,
Absorptivity
2019
From the earliest observations of ozone in the lower atmosphere in the 19th century, both measurement methods and the portion of the globe observed have evolved and changed. These methods have different uncertainties and biases, and the data records differ with respect to coverage (space and time), information content, and representativeness. In this study, various ozone measurement methods and ozone datasets are reviewed and selected for inclusion in the historical record of background ozone levels, based on relationship of the measurement technique to the modern UV absorption standard, absence of interfering pollutants, representativeness of the well-mixed boundary layer and expert judgement of their credibility. There are significant uncertainties with the 19th and early 20th-century measurements related to interference of other gases. Spectroscopic methods applied before 1960 have likely underestimated ozone by as much as 11% at the surface and by about 24% in the free troposphere, due to the use of differing ozone absorption coefficients. There is no unambiguous evidence in the measurement record back to 1896 that typical mid-latitude background surface ozone values were below about 20 nmol mol–1, but there is robust evidence for increases in the temperate and polar regions of the northern hemisphere of 30–70%, with large uncertainty, between the period of historic observations, 1896–1975, and the modern period (1990–2014). Independent historical observations from balloons and aircraft indicate similar changes in the free troposphere. Changes in the southern hemisphere are much less. Regional representativeness of the available observations remains a potential source of large errors, which are difficult to quantify. The great majority of validation and intercomparison studies of free tropospheric ozone measurement methods use ECC ozonesondes as reference. Compared to UV-absorption measurements they show a modest (~1–5% ±5%) high bias in the troposphere, but no evidence of a change with time. Umkehr, lidar, and FTIR methods all show modest low biases relative to ECCs, and so, using ECC sondes as a transfer standard, all appear to agree to within one standard deviation with the modern UV-absorption standard. Other sonde types show an increase of 5–20% in sensitivity to tropospheric ozone from 1970–1995. Biases and standard deviations of satellite retrieval comparisons are often 2–3 times larger than those of other free tropospheric measurements. The lack of information on temporal changes of bias for satellite measurements of tropospheric ozone is an area of concern for long-term trend studies.
Journal Article
Diversity in Current Ecological Thinking: Implications for Environmental Management
by
Wallington, Tabatha J
,
Levin, Simon
,
Hobbs, Richard J
in
Aquatic Pollution
,
Biodiversity
,
Conservation of Natural Resources
2009
Current ecological thinking emphasizes that systems are complex, dynamic, and unpredictable across space and time. What is the diversity in interpretation of these ideas among today's ecologists, and what does this mean for environmental management? This study used a Policy Delphi survey of ecologists to explore their perspectives on a number of current topics in ecology. The results showed general concurrence with nonequilibrium views. There was agreement that disturbance is a widespread, normal feature of ecosystems with historically contingent responses. The importance of recognizing multiple levels of organization and the role of functional diversity in environmental change were also widely acknowledged. Views differed regarding the predictability of successional development, whether “patchiness” is a useful concept, and the benefits of shifting the focus from species to ecosystem processes. Because of their centrality to environmental management, these different views warrant special attention from both managers and ecologists. Such divergence is particularly problematic given widespread concerns regarding the poor linkages between science (here, ecology) and environmental policy and management, which have been attributed to scientific uncertainty and a lack of consensus among scientists, both jeopardizing the transfer of science into management. Several suggestions to help managers deal with these differences are provided, especially the need to interpret broader theory in the context of place-based assessments. The uncertainty created by these differences requires a proactive approach to environmental management, including clearly identifying environmental objectives, careful experimental design, and effective monitoring.
Journal Article
Increase in lysophosphatidate acyltransferase activity in oilseed rape (Brassica napus) increases seed triacylglycerol content despite its low intrinsic flux control coefficient
by
Bates, Ruth E.
,
Fenyk, Stepan
,
Brown, Alexander
in
Acyltransferases - genetics
,
Acyltransferases - metabolism
,
Brassica napus
2019
Lysophosphatidate acyltransferase (LPAAT) catalyses the second step of the Kennedy path-way for triacylglycerol (TAG) synthesis. In this study we expressed Trapaeolum majus LPAAT in Brassica napus (B. napus) cv 12075 to evaluate the effects on lipid synthesis and estimate the flux control coefficient for LPAAT.
We estimated the flux control coefficient of LPAAT in a whole plant context by deriving a relationship between it and overall lipid accumulation, given that this process is a exponential.
Increasing LPAAT activity resulted in greater TAG accumulation in seeds of between 25% and 29%; altered fatty acid distributions in seed lipids (particularly those of the Kennedy pathway); and a redistribution of label from 14C-glycerol between phosphoglycerides.
Greater LPAAT activity in seeds led to an increase in TAG content despite its low intrinsic flux control coefficient on account of the exponential nature of lipid accumulation that amplifies the effect of the small flux increment achieved by increasing its activity. We have also developed a novel application of metabolic control analysis likely to have broad application as it determines the in planta flux control that a single component has upon accumulation of storage products.
Journal Article