1,128 research outputs found

    Current standards and future perspectives in adjuvant treatment for biliary tract cancers

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    Biliary tract cancer, including cholangiocarcinoma (CCA) and gallbladder cancer (GBC) are rare tumours with a rising incidence. Prognosis is poor, since most patients are diagnosed with advanced disease. Only ∼20% of patients are diagnosed with early-stage disease, suitable for curative surgery. Despite surgery performed with potentially-curative intent, relapse rates are high, with around 60-70% of patients expected to have disease recurrence. Most relapses occur in the form of distant metastases, with a predominance of liver spread. In view of high tumour recurrence, adjuvant strategies have been explored for many years, in the form of radiotherapy, chemo-radiotherapy and chemotherapy. Historically, few randomised trials were available, including a variety of additional tumours (e.g. pancreatic and ampullary tumours) and most evidence relied on phase II and retrospective studies, with no high-quality evidence available to define the real benefit derived from adjuvant strategies. Since 2017, three randomised phase III clinical trials have been reported; all recruited patients with resected biliary tract cancer (CCA and GBC) who were randomised to observation alone, or chemotherapy in the form of gemcitabine (BCAT study; included patients diagnosed with extrahepatic CCA only), gemcitabine and oxaliplatin (PRODIGE-12/ACCORD-18; included patients diagnosed with CCA and GBC) or capecitabine (BILCAP; included patients diagnosed with CCA and GBC). While gemcitabine-based chemotherapy failed to show an impact on patient outcome (relapse-free survival (RFS) or overall survival (OS)), the BILCAP study showed a benefit from adjuvant capecitabine in terms of OS (pre-planned sensitivity analysis in the intention-to-treat population and in the per-protocol analysis), with confirmed benefit in terms of RFS. Based on the BILCAP trial, international guidelines recommend adjuvant capecitabine for a period of six months following potentially curative resection of CCA as the current standard of care for resected CCA and GBC. However, BILCAP failed to show OS benefit in the intention-to-treat (non-sensitivity analysis) population (primary end-point), and this finding, as well as some inconsistencies between studies has been criticised and has led to confusion in the biliary tract cancer medical community. This review summarises the adjuvant field in biliary tract cancer, with evidence before and after 2017, and comparison between the latest randomised phase III studies. Potential explanations are presented for differential findings, and future steps are explored

    A dynamic framework for the study of optimal birth intervals reveals the importance of sibling competition and mortality risks

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    Human reproductive patterns have been well studied, but the mechanisms by which physiology, ecology and existing kin interact to affect the life history need quantification. Here, we create a model to investigate how age-specific interbirth intervals adapt to environmental and intrinsic mortality, and how birth patterns can be shaped by competition and help between siblings. The model provides a flexible framework for studying the processes underlying human reproductive scheduling. We developed a state-based optimality model to determine age-dependent and family-dependent sets of reproductive strategies, including the state of the mother and her offspring. We parameterized the model with realistic mortality curves derived from five human populations. Overall, optimal birth intervals increase until the age of 30 after which they remain relatively constant until the end of the reproductive lifespan. Offspring helping each other does not have much effect on birth intervals. Increasing infant and senescent mortality in different populations decreases interbirth intervals. We show that sibling competition and infant mortality interact to lengthen interbirth intervals. In lower-mortality populations, intense sibling competition pushes births further apart. Varying the adult risk of mortality alone has no effect on birth intervals between populations; competition between offspring drives the differences in birth intervals only when infant mortality is low. These results are relevant to understanding the demographic transition, because our model predicts that sibling competition becomes an important determinant of optimal interbirth intervals only when mortality is low, as in post-transition societies. We do not predict that these effects alone can select for menopause

    Identification of areas for improvement in the management of bone metastases in patients with neuroendocrine neoplasms

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    Background: There is no global consensus on the optimal management of bone metastases (BMs) in neuroendocrine neoplasms (NENs). Objectives: To review current management and outcomes of patients with BMs in NENs, in order to identify areas for improvement. Methods: A retrospective study of all patients with NENs, except Grade 3 (G3) lung NENs (April 2002-March 2018) was conducted. Baseline characteristics, nature of BMs, treatment received and overall survival (OS) were evaluated. Statistical analyses were performed using SPSS v23.0/STATA v12. Results: Of 1212 patients, 85 (7%) had BMs; median age 58 years. The majority had a gastro-entero-pancreatic primary (49%, n=42) followed by lung (25%, n=21), unknown primary (20%, n=17), and “others” (6%, n=5). Two-thirds (n=57) had G1-2 neuroendocrine tumours, and 41% (n=35) had functional tumours. Overall, 28% (n=24) presented with synchronous BMs at first NEN diagnosis, and 55% (n=47) developed BMs at the same time as other distant metastases. For the subpopulation of patients in whom BMs developed metachronously to other distant metastases (45%, n=38), median time to development of BMs was 14.0 months. BMs were ‘widespread’ in 61% (n=52). Although only 22% (n=19) reported symptoms at initial diagnosis of BMs, most (78%) developed symptoms at some time during the follow-up period (pain/hypercalcaemia 64%, skeletal-related events 20%). BMs were mainly managed with analgesia (44%, n=37). Radiotherapy and bisphosphonates were used in 34% (n=29) and 22% (n=19), respectively. Surgery was rarely performed (2%, n=2). Median OS from identification of BMs was 31.0 months, and 18.9 months from development of BMs-related symptoms. Conclusions: In this cohort study, most patients with BMs developed symptoms. The utility of radiotherapy and/or bisphosphonates should be prospectively and systematically explored further for its potential impact on patients’ quality of life and survival outcomes

    Effect of concrete slats, three mat types and out-wintering pads on performance and welfare of finishing beef steers

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    peer-reviewedBackground The objective was to investigate the effect of placing mats on concrete slatted floors on performance, behaviour, hoof condition, dirt scores, physiological and immunological variables of beef steers, and to compare responses with animals on out-wintering pads. Continental crossbred beef steers [n = 360; mean (±SD) initial live weight 539 kg (42.2)] were blocked by breed and live weight and randomly assigned to one of five treatments; (1) Concrete slats alone, (2) Mat 1 (Natural Rubber structure) (Durapak Rubber Products), (3) Mat 2 (Natural rubber structure) (EasyFix), (4) Mat 3 (modified ethylene vinyl acetate (EVA) foam structure) and (5) Out-wintering pads (OWP’s). Results Animals on the OWPs had a greater (P  0.05) as the other treatments. Animals on the OWPs had reduced lying percentage time compared with all the other treatments. Dry matter (DM) intake was greater for animals on the OWPs compared with all the other treatments. Carcass weight, kill out proportion, carcass fat score, carcass composition score, FCR and physiological responses were similar (P > 0.05) among treatments. No incidence of laminitis was observed among treatments. The number of hoof lesions was greater on all mat types (P < 0.05) compared with concrete slats and OWP treatments. Dirt scores were greater (P < 0.05) for animals on OWPs when measured on days 42, 84, 105, 126 and 150 compared with animals on slats. Conclusions Under the conditions adopted for the present study, there was no evidence to suggest that animals housed on bare concrete slats were disadvantaged in respect of animal welfare compared with animals housed on other floor types. It is concluded that the welfare of steers was not adversely affected by slats compared with different mat types or OWPs

    Different reactions to adverse neighborhoods in games of cooperation

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    In social dilemmas, cooperation among randomly interacting individuals is often difficult to achieve. The situation changes if interactions take place in a network where the network structure jointly evolves with the behavioral strategies of the interacting individuals. In particular, cooperation can be stabilized if individuals tend to cut interaction links when facing adverse neighborhoods. Here we consider two different types of reaction to adverse neighborhoods, and all possible mixtures between these reactions. When faced with a gloomy outlook, players can either choose to cut and rewire some of their links to other individuals, or they can migrate to another location and establish new links in the new local neighborhood. We find that in general local rewiring is more favorable for the evolution of cooperation than emigration from adverse neighborhoods. Rewiring helps to maintain the diversity in the degree distribution of players and favors the spontaneous emergence of cooperative clusters. Both properties are known to favor the evolution of cooperation on networks. Interestingly, a mixture of migration and rewiring is even more favorable for the evolution of cooperation than rewiring on its own. While most models only consider a single type of reaction to adverse neighborhoods, the coexistence of several such reactions may actually be an optimal setting for the evolution of cooperation.Comment: 12 pages, 5 figures; accepted for publication in PLoS ON

    Distances and ages of globular clusters using Hipparcos parallaxes of local subdwarfs

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    We discuss the impact of Population II and Globular Cluster (GCs) stars on the derivation of the age of the Universe, and on the study of the formation and early evolution of galaxies, our own in particular. The long-standing problem of the actual distance scale to Population II stars and GCs is addressed, and a variety of different methods commonly used to derive distances to Population II stars are briefly reviewed. Emphasis is given to the discussion of distances and ages for GCs derived using Hipparcos parallaxes of local subdwarfs. Results obtained by different authors are slightly different, depending on different assumptions about metallicity scale, reddenings, and corrections for undetected binaries. These and other uncertainties present in the method are discussed. Finally, we outline progress expected in the near future.Comment: Invited review article to appear in: `Post-Hipparcos Cosmic Candles', A. Heck & F. Caputo (Eds), Kluwer Academic Publ., Dordrecht, in press. 22 pages including 3 tables and 2 postscript figures, uses Kluwer's crckapb.sty LaTeX style file, enclose

    Advanced intrahepatic cholangiocarcinoma: post-hoc analysis of the ABC-01, -02 and -03 clinical trials

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    Background The incidence of intrahepatic cholangiocarcinoma (iCCA) is increasing. The aim was to provide reference survival data for patients with advanced iCCA treated with first-line cisplatin-gemcitabine chemotherapy (current standard of care). Methods Individual data from patients with iCCA recruited into the prospective, randomised Advanced Biliary tract Cancer (ABC)-01, -02 and -03 studies were retrieved. The prevalence and survival of liver-only iCCA was also assessed. Survival analysis was performed using univariate and multivariable Cox Regression. All statistical tests were two-sided. Results Of 534 patients recruited into the ABC-01, -02 and -03 studies, 109 (20.4%) had iCCA. Most patients (n = 86; 78.9%) had metastatic disease at the time of recruitment; 52 patients (47.7%) had liver-only disease. Following randomisation, 66 (60.6%) iCCA patients received cisplatin/gemcitabine. The median progression-free (PFS) and overall survival (OS) was 8.4 months (95%confdence interval [CI] = 5.9-8.9) and 15.4 months (95%CI = 11.1-17.9), respectively. Of these 66 patients, 34 patients (51.5%) had liver-only disease. Following chemotherapy, 30 (45.5%) and 21 (31.8%) were progression free at 3 and 6 months from chemotherapy commencement, respectively. Median OS for patients with liver-only iCCA at diagnosis, and after 3 and 6 months of chemotherapy was 16.7 months (95% confidence interval [CI] = 8.7-20.2), 17.9 (95%CI = 11.7-20.9) and 18.9 (95%CI = 16.7-25.9) months, respectively. Multivariable analysis confirmed that iCCA had a longer OS compared to other non-iCCA BTCs (hazard ratio = 0.58, 95%CI = 0.35-0.95; p-value = 0.03); liver-only iCCA patients also showed longer OS even though findings did not reach statistical significance (hazard ratio = 0.65, 95%CI = 0.36-1.19; p-value = 0.16). Conclusions Patients diagnosed with advanced iCCA have a better OS compared to other BTCs; similar trend was identified for patients diagnosed with liver-only iCCA. These findings are to be considered for future clinical trial design

    Lattice Boltzmann simulations of soft matter systems

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    This article concerns numerical simulations of the dynamics of particles immersed in a continuum solvent. As prototypical systems, we consider colloidal dispersions of spherical particles and solutions of uncharged polymers. After a brief explanation of the concept of hydrodynamic interactions, we give a general overview over the various simulation methods that have been developed to cope with the resulting computational problems. We then focus on the approach we have developed, which couples a system of particles to a lattice Boltzmann model representing the solvent degrees of freedom. The standard D3Q19 lattice Boltzmann model is derived and explained in depth, followed by a detailed discussion of complementary methods for the coupling of solvent and solute. Colloidal dispersions are best described in terms of extended particles with appropriate boundary conditions at the surfaces, while particles with internal degrees of freedom are easier to simulate as an arrangement of mass points with frictional coupling to the solvent. In both cases, particular care has been taken to simulate thermal fluctuations in a consistent way. The usefulness of this methodology is illustrated by studies from our own research, where the dynamics of colloidal and polymeric systems has been investigated in both equilibrium and nonequilibrium situations.Comment: Review article, submitted to Advances in Polymer Science. 16 figures, 76 page

    Atherosclerosis in young Brazilians suffering violent deaths: a pathological study

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    <p>Abstract</p> <p>Background</p> <p>Atherosclerosis is the leading cause of coronary heart disease and ischemic stroke, which can cause sudden death in adulthood. In general, the clinical manifestations of cardiovascular diseases are caused by atherosclerosis, which is a process that starts during middle age. More recent studies indicate that the atherosclerotic process begins during childhood.</p> <p>Methods</p> <p>To evaluate the extent of atherosclerotic disease in young Brazilians, we conducted a study of the pathological alterations in the major arteries of victims of violent death. Samples of the right carotid artery, left coronary artery, and thoracic aorta of young victims of violent death were analyzed and graded in accordance with the histological atherosclerotic lesion types proposed by the American Heart Association. Samples were collected from 100 individuals who had died from external causes, aged from 12 to 33 years.</p> <p>Results</p> <p>The majority of cases (83%) were male, and 66% of deaths were homicides caused by firearms. The median age was 20.0 years and mean body mass index was 20.9 kg/m<sup>2</sup>. Of the right carotid artery specimens, 3% were normal, 55% had type I, 40% had type II, 1% had type III, and 1% had type IV atherosclerotic lesions. Of the left coronary artery specimens, 5% were normal, 48% had type I, 41% had type II, 3% had type III, and 3% had type IV lesions. Of the thoracic aorta specimens, none were normal, 13% had type I, 64% had type II, 22% had type III, and 1% had type IV lesions. Overall, 97.34% of arteries examined had some degree of atherosclerosis. The most common histological type was type II (foam cells). No thoracic aorta specimens were normal, and the coronary artery specimens had the most atherosclerosis.</p> <p>Conclusions</p> <p>Our results show a high prevalence of atherosclerotic lesions among young people in Brazil. Intervention should be undertaken to decrease the rate of sudden cardiac death in the adult population.</p
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