891 resultados para embryonic death
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The paper is motivated by the valuation problem of guaranteed minimum death benefits in various equity-linked products. At the time of death, a benefit payment is due. It may depend not only on the price of a stock or stock fund at that time, but also on prior prices. The problem is to calculate the expected discounted value of the benefit payment. Because the distribution of the time of death can be approximated by a combination of exponential distributions, it suffices to solve the problem for an exponentially distributed time of death. The stock price process is assumed to be the exponential of a Brownian motion plus an independent compound Poisson process whose upward and downward jumps are modeled by combinations (or mixtures) of exponential distributions. Results for exponential stopping of a Lévy process are used to derive a series of closed-form formulas for call, put, lookback, and barrier options, dynamic fund protection, and dynamic withdrawal benefit with guarantee. We also discuss how barrier options can be used to model lapses and surrenders.
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The aim was to examine the capacity of commonly used type 2 diabetes mellitus (T2DM) risk scores to predict overall mortality. The US-based NHANES III (n = 3138; 982 deaths) and the Swiss-based CoLaus study (n = 3946; 191 deaths) were used. The predictive value of eight T2DM risk scores regarding overall mortality was tested. The Griffin score, based on few self-reported parameters, presented the best (NHANES III) and second best (CoLaus) predictive capacity. Generally, the predictive capacity of scores based on clinical (anthropometrics, lifestyle, history) and biological (blood parameters) data was not better than of scores based solely on clinical self-reported data. T2DM scores can be validly used to predict mortality risk in general populations without diabetes. Comparison with other scores could further show whether such scores also suit as a screening tool for quick overall health risk assessment.
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Fas apoptosis inhibitory molecule (FAIM) is a protein identified as an antagonist of Fas-induced cell death. We show that FAIM overexpression fails to rescue neurons from trophic factor deprivation, but exerts a marked neurite growth–promoting action in different neuronal systems. Whereas FAIM overexpression greatly enhanced neurite outgrowth from PC12 cells and sympathetic neurons grown with nerve growth factor (NGF), reduction of endogenous FAIM levels by RNAi decreased neurite outgrowth in these cells. FAIM overexpression promoted NF-κB activation, and blocking this activation by using a super-repressor IκBα or by carrying out experiments using cortical neurons from mice that lack the p65 NF-κB subunit prevented FAIM-induced neurite outgrowth. The effect of FAIM on neurite outgrowth was also blocked by inhibition of the Ras–ERK pathway. Finally, we show that FAIM interacts with both Trk and p75 neurotrophin receptor NGF receptors in a ligand-dependent manner. These results reveal a new function of FAIM in promoting neurite outgrowth by a mechanism involving activation of the Ras–ERK pathway and NF-κB.
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While historical studies of the Atlantic slave trade have amply demonstrated the magnitude of slave mortality during the Middle Passage, only recently have they started to examine how the captives might have endured and coped with this traumatic experience. Although it constitutes a major topos in African diasporic culture, the Middle Passage has only occasionally been represented directly and in details in novels and in films. This article examines three recent narratives of the Middle Passage, Fred D'Aguiar's novel Feeding the Ghosts (1998), Guy Deslauriers's film Passage du milieu (2000), and Stephanie Smallwood's historical study Saltwater Slavery: A Middle Passage from Africa to American Diaspora (2007). Beyond their individual poetic, aesthetic, and scholarly qualities, what is most striking about these three texts is that they all use the figure of the living dead in order to explore the captives' experience of the transatlantic journey. If the ghastly quality of the living dead powerfully captures the life-threatening material and physical conditions the captives endured on the voyage, its dual, liminal character also allows D'Aguiar, Deslauriers, and Smallwood to represent the metaphysical, psychological, social, and cultural journey they were forced to undertake. Through their use of the trope of the living dead, these three texts show that if death is indeed a central aspect of the experience of the Middle Passage, it impacts the captives in ways that go well beyond the issue of mortality.
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BACKGROUND: Cancer mortality statistics for 2015 were projected from the most recent available data for the European Union (EU) and its six more populous countries. Prostate cancer was analysed in detail. PATIENTS AND METHODS: Population and death certification data from stomach, colorectum, pancreas, lung, breast, uterus, prostate, leukaemias and total cancers were obtained from the World Health Organisation database and Eurostat. Figures were derived for the EU, France, Germany, Italy, Poland, Spain and the UK. Projected 2015 numbers of deaths by age group were obtained by linear regression on estimated numbers of deaths over the most recent time period identified by a joinpoint regression model. RESULTS: A total of 1 359 100 cancer deaths are predicted in the EU in 2015 (766 200 men and 592 900 women), corresponding to standardised death rates of 138.4/100 000 men and 83.9/100 000 women, falling 7.5% and 6%, respectively, since 2009. In men, predicted rates for the three major cancers (lung, colorectum and prostate) are lower than in 2009, falling 9%, 5% and 12%. Prostate cancer showed predicted falls of 14%, 17% and 9% in the 35-64, 65-74 and 75+ age groups. In women, breast and colorectal cancers had favourable trends (-10% and -8%), but predicted lung cancer rates rise 9% to 14.24/100 000 becoming the cancer with the highest rate, reaching and possibly overtaking breast cancer rates-though the total number of deaths remain higher for breast (90 800) than lung (87 500). Pancreatic cancer has a negative outlook in both sexes, rising 4% in men and 5% in women between 2009 and 2015. CONCLUSIONS: Cancer mortality predictions for 2015 confirm the overall favourable cancer mortality trend in the EU, translating to an overall 26% fall in men since its peak in 1988, and 21% in women, and the avoidance of over 325 000 deaths in 2015 compared with the peak rate.
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Recently, a handful of intergenic long noncoding RNAs (lncRNAs) have been shown to compete with mRNAs for binding to miRNAs and to contribute to development and disease. Beyond these reports, little is yet known of the extent and functional consequences of miRNA-mediated regulation of mRNA levels by lncRNAs. To gain further insight into lncRNA-mRNA miRNA-mediated crosstalk, we reanalyzed transcriptome-wide changes induced by the targeted knockdown of over 100 lncRNA transcripts in mouse embryonic stem cells (mESCs). We predicted that, on average, almost one-fifth of the transcript level changes induced by lncRNAs are dependent on miRNAs that are highly abundant in mESCs. We validated these findings experimentally by temporally profiling transcriptome-wide changes in gene expression following the loss of miRNA biogenesis in mESCs. Following the depletion of miRNAs, we found that >50% of lncRNAs and their miRNA-dependent mRNA targets were up-regulated coordinately, consistent with their interaction being miRNA-mediated. These lncRNAs are preferentially located in the cytoplasm, and the response elements for miRNAs they share with their targets have been preserved in mammals by purifying selection. Lastly, miRNA-dependent mRNA targets of each lncRNA tended to share common biological functions. Post-transcriptional miRNA-mediated crosstalk between lncRNAs and mRNA, in mESCs, is thus surprisingly prevalent, conserved in mammals, and likely to contribute to critical developmental processes.
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Postmortem imaging consists in the non-invasive examination of bodies using medical imaging techniques. However, gas volume quantification and the interpretation of the gas collection results from cadavers remain difficult. We used whole-body postmortem multi-detector computed tomography (MDCT) followed by a full autopsy or external examination to detect the gaseous volumes in bodies. Gases were sampled from cardiac cavities, and the sample compositions were analyzed by headspace gas chromatography-mass spectrometry/thermal conductivity detection (HS-GC-MS/TCD). Three categories were defined according to the presumed origin of the gas: alteration/putrefaction, high-magnitude vital gas embolism (e.g., from scuba diving accident) and gas embolism of lower magnitude (e.g., following a traumatic injury). Cadaveric alteration gas was diagnosed even if only one gas from among hydrogen, hydrogen sulfide or methane was detected. In alteration cases, the carbon dioxide/nitrogen ratio was often >0.2, except in the case of advanced alteration, when methane presence was the best indicator. In the gas embolism cases (vital or not), hydrogen, hydrogen sulfide and methane were absent. Moreover, with high-magnitude vital gas embolisms, carbon dioxide content was >20%, and the carbon dioxide/nitrogen ratio was >0.2. With gas embolisms of lower magnitude (gas presence consecutive to a traumatic injury), carbon dioxide content was <20% and the carbon dioxide/nitrogen ratio was often <0.2. We found that gas analysis provided useful assistance to the postmortem imaging diagnosis of causes of death. Based on the quantifications of gaseous cardiac samples, reliable indicators were determined to document causes of death. MDCT examination of the body must be performed as quickly as possible, as does gas sampling, to avoid generating any artifactual alteration gases. Because of cardiac gas composition analysis, it is possible to distinguish alteration gases and gas embolisms of different magnitudes.
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Three important studies on acute exacerbations of chronic obstructive pulmonary disease (ECOPD)have been published in Thorax. Two of them, by Chang et al1(see page 764) and Hoiset et al2 (see page 775), show the importance of the cardiac biomarkers troponin T and NT-BNP (Nterminal pro-B-type natriuretic peptide) as strong predictors of the increased risk of death of patients hospitalised because of ECOPD.1 2.....
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In vertebrates, early brain development takes place at the expanded anterior end of the neural tube. After closure of the anterior neuropore, the brain wall forms a physiologically sealed cavity that encloses embryonic cerebrospinal fluid (E-CSF), a complex and protein-rich fluid that is initially composed of trapped amniotic fluid. E-CSF has several crucial roles in brain anlagen development. Recently, we reported the presence of transient blood-CSF barrier located in the brain stem lateral to the ventral midline, at the mesencephalon and prosencephalon level, in chick and rat embryos by transporting proteins, water, ions and glucose in a selective manner via transcellular routes. To test the actual relevance of the control of E-CSF composition and homeostasis on early brain development by this embryonic blood-CSF barrier, we block the activity of this barrier by treating the embryos with 6-aminonicotinamide gliotoxin (6-AN). We demonstrate that 6-AN treatment in chick embryos blocks protein transport across the embryonic blood-CSF barrier, and that the disruption of the barrier properties is due to the cease transcellular caveolae transport, as detected by CAV-1 expression cease. We also show that the lack of protein transport across the embryonic blood-CSF barrier influences neuroepithelial cell survival, proliferation and neurogenesis, as monitored by neurepithelial progenitor cells survival, proliferation and neurogenesis. The blockage of embryonic blood-CSF transport also disrupts water influx to the E-CSF, as revealed by an abnormal increase in brain anlagen volume. These experiments contribute to delineate the actual extent of this blood-CSF embryonic barrier controlling E-CSF composition and homeostasis and the actual important of this control for early brain development, as well as to elucidate the mechanism by which proteins and water are transported thought transcellular routes across the neuroectoderm, reinforcing the crucial role of E-CSF for brain development.
Resumo:
In vertebrates, early brain development takes place at the expanded anterior end of the neural tube, which is filled with embryonic cerebrospinal fluid (E-CSF). We have recently identified a transient blood-CSF barrier that forms between embryonic days E3 and E4 in chick embryos and that is responsible for the transport of proteins and control of E-CSF homeostasis, including osmolarity. Here we examined the presence of glucose transporter GLUT-1 as well the presence of caveolae-structural protein Caveolin1 (CAV-1) in the embryonic blood-CSF barrier which may be involved in the transport of glucose and of proteins, water and ions respectively across the neuroectoderm. In this paper we demonstrate the presence of GLUT-1 and CAV-1 in endothelial cells of blood vessels as well as in adjacent neuroectodermal cells, located in the embryonic blood-CSF barrier. In blood vessels, these proteins were detected as early as E4 in chick embryos and E12.7 in rat embryos, i.e. the point at which the embryonic blood-CSF barrier acquires this function. In the neuroectoderm of the embryonic blood-CSF barrier, GLUT-1 was also detected at E4 and E12.7 respectively, and CAV-1 was detected shortly thereafter in both experimental models. These experiments contribute to delineating the extent to which the blood-CSF embryonic barrier controls E-CSF composition and homeostasis during early stages of brain development in avians and mammals. Our results suggest the regulation of glucose transport to the E-CSF by means of GLUT-1 and also suggest a mechanism by which proteins are transported via transcellular routes across the neuroectoderm, thus reinforcing the crucial role of E-CSF in brain development.
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Sudden cardiac death (SCD) is by definition unexpected and cardiac in nature. The investigation is almost invariably performed by a forensic pathologist. Under these circumstances the role of the forensic pathologist is twofold: (1.) to determine rapidly and efficiently the cause and manner of death and (2.) to initiate a multidisciplinary process in order to prevent further deaths in existing family members. If the death is determined to be due to "natural" causes the district attorney in charge often refuses further examinations. However, additional examinations, i.e. extensive histopathological investigations and/or molecular genetic analyses, are necessary in many cases to clarify the cause of death. The Swiss Society of Legal Medicine created a multidisciplinary working group together with clinical and molecular geneticists and cardiologists in the hope of harmonising the approach to investigate SCD. The aim of this paper is to close the gap between the Swiss recommendations for routine forensic post-mortem cardiac examination and clinical recommendations for genetic testing of inherited cardiac diseases; this is in order to optimise the diagnostic procedures and preventive measures for living family members. The key points of the recommendations are (1.) the forensic autopsy procedure for all SCD victims under 40 years of age, (2.) the collection and storage of adequate samples for genetic testing, (3.) communication with the families, and (4.) a multidisciplinary approach including cardiogenetic counselling.
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A role for the NADPH oxidases NOX1 and NOX2 in liver fibrosis has been proposed, but the implication of NOX4 is poorly understood yet. The aim of this work was to study the functional role of NOX4 in different cell populations implicated in liver fibrosis: hepatic stellate cells (HSC), myofibroblats (MFBs) and hepatocytes. Two different mice models that develop spontaneous fibrosis (Mdr2−/−/p19ARF−/−, Stat3Δhc/Mdr2−/−) and a model of experimental induced fibrosis (CCl4) were used. In addition, gene expression in biopsies from chronic hepatitis C virus (HCV) patients or non-fibrotic liver samples was analyzed. Results have indicated that NOX4 expression was increased in the livers of all animal models, concomitantly with fibrosis development and TGF-β pathway activation. In vitro TGF-β-treated HSC increased NOX4 expression correlating with transdifferentiation to MFBs. Knockdown experiments revealed that NOX4 downstream TGF-β is necessary for HSC activation as well as for the maintenance of the MFB phenotype. NOX4 was not necessary for TGF-β-induced epithelial-mesenchymal transition (EMT), but was required for TGF-β-induced apoptosis in hepatocytes. Finally, NOX4 expression was elevated in patients with hepatitis C virus (HCV)-derived fibrosis, increasing along the fibrosis degree. In summary, fibrosis progression both in vitro and in vivo (animal models and patients) is accompanied by increased NOX4 expression, which mediates acquisition and maintenance of the MFB phenotype, as well as TGF-β-induced death of hepatocytes.