150 research outputs found

    The effect on survival of continuing chemotherapy to near death

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    <p>Abstract</p> <p>Background</p> <p>Overuse of anti-cancer therapy is an important quality-of-care issue. An aggressive approach to treatment can have negative effects on quality of life and cost, but its effect on survival is not well-defined.</p> <p>Methods</p> <p>Using the Surveillance, Epidemiology, and End Results-Medicare database, we identified 7,879 Medicare-enrolled patients aged 65 or older who died after having survived at least 3 months after diagnosis of advanced non-small cell lung cancer (NSCLC) between 1991 and 1999. We used Cox proportional hazards regression analysis, propensity scores, and instrumental variable analysis (IVA) to compare survival among patients who never received chemotherapy (n = 4,345), those who received standard chemotherapy but not within two weeks prior to death (n = 3,235), and those who were still receiving chemotherapy within 14 days of death (n = 299). Geographic variation in the application of chemotherapy was used as the instrument for IVA.</p> <p>Results</p> <p>Receipt of chemotherapy was associated with a 2-month improvement in overall survival. However, based on three different statistical approaches, no additional survival benefit was evident from continuing chemotherapy within 14 days of death. Moreover, patients receiving chemotherapy near the end of life were much less likely to enter hospice (81% versus 51% with no chemotherapy and 52% with standard chemotherapy, P < 0.001), or were more likely to be admitted within only 3 days of death.</p> <p>Conclusions</p> <p>Continuing chemotherapy for advanced NSCLC until very near death is associated with a decreased likelihood of receiving hospice care but not prolonged survival. Oncologists should strive to discontinue chemotherapy as death approaches and encourage patients to enroll in hospice for better end-of-life palliative care.</p

    Founders, Feminists, and a Fascist -- Some Notable Women in the Missouri Section of the MAA

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    In the history of the Missouri Section of the MAA, some of the more interesting people who influenced the growth and development of the section through the years were and are women. In this chapter, we discuss the contributions of a few (certainly not all) of these women to the Missouri Section and mathematics as a whole, including Emily Kathryn Wyant (founder of KME), Margaret F. Willerding (who dealt with sexism in the 1940s), Maria Castellani (an official in Mussolini’s Italy before coming to America), and T. Christine Stevens (co-founder of Project NExT). Without them, and others like them, both mathematics and the Missouri Section of the MAA would be poorer

    Supercooled Southern Ocean waters

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    In cold polar waters, temperatures sometimes drop below the freezing point, a process referred to as supercooling. However, observational challenges in polar regions limit our understanding of the spatial and temporal extent of this phenomenon. We here provide observational evidence that supercooled waters are much more widespread in the seasonally ice-covered Southern Ocean than previously reported. In 5.8% of all analyzed hydrographic profiles south of 55°S, we find temperatures below the surface freezing point (“potential” supercooling), and half of these have temperatures below the local freezing point (“in situ” supercooling). Their occurrence doubles when neglecting measurement uncertainties. We attribute deep coastal-ocean supercooling to melting of Antarctic ice shelves and surface-induced supercooling in the seasonal sea-ice region to wintertime sea-ice formation. The latter supercooling type can extend down to the permanent pycnocline due to convective sinking plumes—an important mechanism for vertical tracer transport and water-mass structure in the polar ocean

    A post-mortem survey on end-of-life decisions using a representative sample of death certificates in Flanders, Belgium: research protocol

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    Background: Reliable studies of the incidence and characteristics of medical end-of-life decisions with a certain or possible life shortening effect (ELDs) are indispensable for an evidence-based medical and societal debate on this issue. This article presents the protocol drafted for the 2007 ELD Study in Flanders, Belgium, and outlines how the main aims and challenges of the study (i.e. making reliable incidence estimates of end-of-life decisions, even rare ones, and describing their characteristics; allowing comparability with past ELD studies; guaranteeing strict anonymity given the sensitive nature of the research topic; and attaining a sufficient response rate) are addressed in a post-mortem survey using a representative sample of death certificates. Study design: Reliable incidence estimates are achievable by using large at random samples of death certificates of deceased persons in Flanders (aged one year or older). This entails the cooperation of the appropriate administrative authorities. To further ensure the reliability of the estimates and descriptions, especially of less prevalent end-of-life decisions (e.g. euthanasia), a stratified sample is drawn. A questionnaire is sent out to the certifying physician of each death sampled. The questionnaire, tested thoroughly and avoiding emotionally charged terms is based largely on questions that have been validated in previous national and European ELD studies. Anonymity of both patient and physician is guaranteed through a rigorous procedure, involving a lawyer as intermediary between responding physicians and researchers. To increase response we follow the Total Design Method (TDM) with a maximum of three follow-up mailings. Also, a non-response survey is conducted to gain insight into the reasons for lack of response. Discussion: The protocol of the 2007 ELD Study in Flanders, Belgium, is appropriate for achieving the objectives of the study; as past studies in Belgium, the Netherlands, and other European countries have shown, strictly anonymous and thorough surveys among physicians using a large, stratified, and representative death certificate sample are most suitable in nationwide studies of incidence and characteristics of end-of-life decisions. There are however also some limitations to the study design

    Modulation of endogenous antioxidant defense and the progression of kidney disease in multi-heritage groups of patients with type 2 diabetes: PRospective EValuation of Early Nephropathy and its Treatment (PREVENT).

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    BACKGROUND: Diabetes is the western world's leading cause of end-stage renal disease. Glucose-dependent, oxidative stress is linked to the development of renal inflammation and sclerosis, which, in animal models of diabetes, can be prevented by anti-oxidative treatment. Patients of non-Caucasian heritage have low activity of the selenoprotein, antioxidant enzyme, glutathione peroxidase (GPx) and its co-factor vitamin E, which may be linked to their increased propensity to developing end-stage renal disease. RESEARCH DESIGN AND METHODS: We have designed a double-blind, randomized, placebo controlled study with selenium and/or vitamin E versus placebo as the interventions for patients with type 2 diabetes and chronic kidney disease (CKD) stages 1-3. A 2 × 2 factorial design will allow a balanced representation of the heritage groups exposed to each intervention. The primary biochemical outcome is change in GPx activity, and clinical outcome measure is the actual, rate of-and/or percentage change in estimated glomerular filtration rate (eGFR) from baseline. Analysis will be with a marginal model for longitudinal data using Generalized Estimating Equations corrected for measures of baseline serum antioxidant enzyme activities (GPx, superoxide dismutase and catalase), micronutrient levels (vitamins E and C), measures of inflammation (interleukin 6, c-reactive protein and monocyte chemoattractant protein-1) and markers of oxidative damage (plasma 8-isoprostaglandin F2α and urinary 8-hydroxydeoxyguanosine). EXPECTED RESULTS: The study will assess the relationship between GPx activity, oxidative stress, inflammation and eGFR. It will test the null hypothesis that antioxidant therapy does not influence the activity of GPx or other antioxidant enzymes and/or alter the rate of change in eGFR in these patient groups. CONCLUSIONS: Outcome data on the effect of antioxidants in human diabetic renal disease is limited. Previous post hoc analyses have not shown a beneficial effect of vitamin E on renal function. A recent trial of a pharmaceutical antioxidant agent, improved eGFR, but in patients with advanced diabetes-related chronic kidney disease its use was associated with an increased incidence of cardiovascular events. We will explore whether the nutritional antioxidants, vitamin E and selenium alone, or in combination in patients at high risk of renal disease progression, forestalls a reduction in eGFR. The study will describe whether endogenous antioxidant enzyme defenses can be safely modified by this intervention and how this is associated with changes in markers of oxidative stress. Trial registration ISRCTN 97358113. Registered 21st September 2009

    The Moderating Effect of Mental Toughness: Perception of Risk and Belief in the Paranormal

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    This research demonstrates that higher levels of mental toughness provide cognitive-perceptual processing advantages when evaluating risk. No previous research, however, has examined mental toughness in relation to perception of risk and paranormal belief (a variable associated with distorted perception of causality and elevated levels of perceived risk). Accordingly, the present paper investigated relationships between these factors. A sample of 174 participants completed self-report measures assessing mental toughness, general perception of risk, and paranormal belief. Responses were analyzed via correlations and moderation analyses. Results revealed that mental toughness correlated negatively with perception of risk and paranormal belief, whereas paranormal belief correlated positively with perception of risk. For the moderation effects, simple slopes analyses indicated that high levels of MT and subfactors of commitment and confidence reduced the strength of association between paranormal belief and perceived risk. Therefore, MT potentially acts as a protective factor among individuals who believe in the paranormal, reducing the tendency to perceive elevated levels of risk

    Ethnic differences in the +405 and -460 vascular endothelial growth factor polymorphisms and peripheral neuropathy in patients with diabetes residing in a North London, community in the United Kingdom.

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    BACKGROUND: There are marked ethnic differences in the susceptibility to the long-term diabetic vascular complications including sensory neuropathy. The vascular endothelial growth factor (VEGF) +405 (C/G) and -460 (T/C) polymorphisms are associated with retinopathy and possibly with nephropathy, however no information is available on their relationship with peripheral neuropathy. Therefore, we examined the prevalence of these VEGF genotypes in a multi-ethnic cohort of patients with diabetes and their relationship with evident peripheral diabetic neuropathy. METHODS: In the current investigation, we studied 313 patients with diabetes mellitus of African-Caribbean, Indo-Asian and Caucasian ethnic origin residing in an inner-city community in London, United Kingdom attending a single secondary care centre. Genotyping was performed for the VEGF +405 and VEGF -460 polymorphisms using a pyrosequencing technique. RESULTS: Forty-nine patients (15.6%) had clinical evidence of peripheral neuropathy. Compared to Caucasian patients, African-Caribbean and Indo-Asian patients had lower incidence of neuropathy (24.6%, 14.28%, 6.7%, respectively; P = 0.04). The frequency of the VEGF +405 GG genotype was more common in Indo-Asian patients compared to African-Caribbean and Caucasian patients (67.5%, 45.3%, 38.4%, respectively; p ≤ 0.02). The G allele was more common in patients with type 2 diabetes of Indo-Asian origin compared to African-Caribbean and Caucasian origin (p ≤ 0.02). There was no difference between the ethnic groups in VEGF -460 genotypes. The distributions of the VEGF +405 and VEGF -460 genotypes were similar between the diabetic patients with and without neuropathy. CONCLUSIONS: In this cohort of patients, VEGF +405 and VEGF -460 polymorphisms were not associated with evident diabetic peripheral neuropathy, however an association was found between VEGF +405 genotypes and Indo-Asian which might have relevance to their lower rates of ulceration and amputation. This finding highlights the need for further investigation of any possible relationship between VEGF genotype, circulating VEGF concentrations and differential vulnerability to peripheral neuropathy amongst diabetic patients of different ethnic backgrounds

    The study of atmospheric ice-nucleating particles via microfluidically generated droplets

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    Ice-nucleating particles (INPs) play a significant role in the climate and hydrological cycle by triggering ice formation in supercooled clouds, thereby causing precipitation and affecting cloud lifetimes and their radiative properties. However, despite their importance, INP often comprise only 1 in 10³–10⁶ ambient particles, making it difficult to ascertain and predict their type, source, and concentration. The typical techniques for quantifying INP concentrations tend to be highly labour-intensive, suffer from poor time resolution, or are limited in sensitivity to low concentrations. Here, we present the application of microfluidic devices to the study of atmospheric INPs via the simple and rapid production of monodisperse droplets and their subsequent freezing on a cold stage. This device offers the potential for the testing of INP concentrations in aqueous samples with high sensitivity and high counting statistics. Various INPs were tested for validation of the platform, including mineral dust and biological species, with results compared to literature values. We also describe a methodology for sampling atmospheric aerosol in a manner that minimises sampling biases and which is compatible with the microfluidic device. We present results for INP concentrations in air sampled during two field campaigns: (1) from a rural location in the UK and (2) during the UK’s annual Bonfire Night festival. These initial results will provide a route for deployment of the microfluidic platform for the study and quantification of INPs in upcoming field campaigns around the globe, while providing a benchmark for future lab-on-a-chip-based INP studies
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