198 research outputs found

    Existence of a fundamental solution of partial differential equations associated to Asian options

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    We prove the existence and uniqueness of the fundamental solution for Kolmogorov operators associated to some stochastic processes, that arise in the Black & Scholes setting for the pricing problem relevant to path dependent options. We improve previous results in that we provide a closed form expression for the solution of the Cauchy problem under weak regularity assumptions on the coefficients of the differential operator. Our method is based on a limiting procedure, whose convergence relies on some barrier arguments and uniform a priori estimates recently discovered

    Untargeted lipidomic features associated with colorectal cancer in a prospective cohort.

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    BackgroundEpidemiologists are beginning to employ metabolomics and lipidomics with archived blood from incident cases and controls to discover causes of cancer. Although several such studies have focused on colorectal cancer (CRC), they all followed targeted or semi-targeted designs that limited their ability to find discriminating molecules and pathways related to the causes of CRC.MethodsUsing an untargeted design, we measured lipophilic metabolites in prediagnostic serum from 66 CRC patients and 66 matched controls from the European Prospective Investigation into Cancer and Nutrition (Turin, Italy). Samples were analyzed by liquid chromatography-high-resolution mass spectrometry (LC-MS), resulting in 8690 features for statistical analysis.ResultsRather than the usual multiple-hypothesis-testing approach, we based variable selection on an ensemble of regression methods, which found nine features to be associated with case-control status. We then regressed each selected feature on time-to-diagnosis to determine whether the feature was likely to be either a potentially causal biomarker or a reactive product of disease progression (reverse causality).ConclusionsOf the nine selected LC-MS features, four appear to be involved in CRC etiology and merit further investigation in prospective studies of CRC. Four other features appear to be related to progression of the disease (reverse causality), and may represent biomarkers of value for early detection of CRC

    Reduced sleep duration affects body composition, dietary intake and quality of life in obese subjects.

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    Purpose Sleep duration has emerged as a crucial factor affecting body weight and feeding behaviour. The aim of our study was to explore the relationship among sleep duration, body composition, dietary intake, and quality of life (QoL) in obese subjects. Methods Body composition was assessed by DXA. ‘‘Sensewear Armband’’ was used to evaluate sleep duration. SF-36 questionnaire was used to evaluate quality of life (QoL). A 3-day dietary record was administered. Subjects were divided into 2 groups: sleep duration[and B300 min/day. Results 137 subjects (105 women and 32 men), age: 49.8 ± 12.4 years, BMI: 38.6 ± 6.7 kg/m2, were enrolled. Sleep duration was B300 min in 30.6 % of subjects. Absolute and relative fat mass (FM) (40.5 ± 9 vs. 36.5 ± 9.1 kg; 40.2 ± 4.7 vs. 36.9 ± 5.6 %), and truncal fat mass (19.2 ± 6.1 vs. 16.6 ± 5 kg; 38.6 ± 5.3 vs. 35.2 ± 5.5 %) were higher in subjects sleeping B300 min when compared to their counterparts (all p.05), whereas just a tendency towards a higher BMI was observed (p = 0.077). Even though energy intake was not different between groups, subjects sleeping B300 min reported a higher carbohydrate consumption per day (51.8 ± 5.1 vs. 48.4 ± 9.2 %, p = 0.038). SF-36 total score was lower in subjects sleeping B300 min (34.2 ± 17.8 vs. 41.4 ± 12.9, p = 0.025). Sleep duration was negatively associated with FM (r = -0.25, p = 0.01) and SF-36 total score (r = -0.31, p.001). The inverse association between sleep duration and SF-36 total score was confirmed by the regression analysis after adjustment for BMI and fat mass (R = 0.43, R2 = 0.19, p = 0.012). Conclusion Reduced sleep duration negatively influences body composition, macronutrient intake, and QoL in obese subjects

    Household pesticide exposure: an online survey and shelf research in the Metropolitan Region of Rio de Janeiro, Brazil

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    Abstract: This study aimed to estimate household pesticide exposure in adult individuals in the Metropolitan Region of Rio de Janeiro, Brazil, and to verify the accessibility of these products in local and online businesses. The data were collected by an online questionnaire (1,015 responses) and a shelf survey in physical and online stores. Among the responses analyzed, 87.5% used pesticides in the previous year, most of which against mosquitoes (64.7%). The most common application method was aerosol spray (38.1%), and the most frequent places of use were bedrooms (29.7%) and living rooms (22.1%). About 30% of respondents reported invasion of pests, and the most common pests were ants (79.1%) and cockroaches (40.4%). Service area (71.6%) and kitchen (17.5%) were the most common storage locations. Approximately 91% of those who lived with children aged under 18 used pesticides. The use of chemical group of pyrethroids prevailed (81.6%), and 90.8% of the reportedly used products are class II [55.7% (highly toxic)] or class III [35.1% (medium toxic)]. The most significant amount of purchased products was in the pest category, followed by mosquitoes. More variety of products were available in online stores than in physical stores. The high exposure of the population to pesticides at household is a public health issue and confirms the need for studies that better assess the risks and consequences of chronic and low-dose exposure to these substances. It is essential to inform the population about the uncertainties and potential risks of indiscriminate use so that they can choose whether to use pesticides in their households

    How does socio-economic position (SEP) get biologically embedded? A comparison of allostatic load and the epigenetic clock(s)

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    Individuals of lower socio-economic position (SEP) carry a heavier burden of disease and morbidity and live shorter lives on average compared with their more advantaged counterparts. This has sparked research interest in the processes and mechanisms via which social adversity gets biologically embedded. The present study directly compares the empirical worth of two candidate mechanisms: Allostatic Load (AL) and the Epigenetic Clock(s) for advancing our understanding of embodiment using a sub-sample of 490 individuals from the Irish Longitudinal Study (TILDA) who were explicitly selected for this purpose based on their inter-generational life course social class trajectory. A battery of 14 biomarkers representing the activity of 4 different physiological systems: Immunological, Cardiovascular, Metabolic, and Renal was used to construct the AL score. Biomarkers were dichotomised into high and low risk groups according to sex-specific quartiles of risk and summed to create a count ranging from 0-14. Three measures of epigenetic age acceleration were computed according to three sets of age-associated Cytosine-phosphate-Guanine (CpG) sites described by Horvath, Hannum and Levine. AL was strongly socially patterned across a number of measures of SEP, while the epigenetic clocks were not. AL partially mediated the association between measures of SEP and an objective measure of physiological functioning: performance on the Timed Up and Go (TUG test). We conclude that AL may represent the more promising candidate for understanding the pervasive link between SEP and health.Peer reviewe

    Role of Diacylglycerol Kinases in Acute Myeloid Leukemia

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    : Diacylglycerol kinases (DGKs) play dual roles in cell transformation and immunosurveillance. According to cancer expression databases, acute myeloid leukemia (AML) exhibits significant overexpression of multiple DGK isoforms, including DGKA, DGKD and DGKG, without a precise correlation with specific AML subtypes. In the TGCA database, high DGKA expression negatively correlates with survival, while high DGKG expression is associated with a more favorable prognosis. DGKA and DGKG also feature different patterns of co-expressed genes. Conversely, the BeatAML and TARGET databases show that high DGKH expression is correlated with shorter survival. To assess the suitability of DGKs as therapeutic targets, we treated HL-60 and HEL cells with DGK inhibitors and compared cell growth and survival with those of untransformed lymphocytes. We observed a specific sensitivity to R59022 and R59949, two poorly selective inhibitors, which promoted cytotoxicity and cell accumulation in the S phase in both cell lines. Conversely, the DGKA-specific inhibitors CU-3 and AMB639752 showed poor efficacy. These findings underscore the pivotal and isoform-specific involvement of DGKs in AML, offering a promising pathway for the identification of potential therapeutic targets. Notably, the DGKA and DGKH isoforms emerge as relevant players in AML pathogenesis, albeit DGKA inhibition alone seems insufficient to impair AML cell viability

    Life-course socioeconomic status and DNA methylation of genes regulating inflammation

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    Background: In humans, low socioeconomic status (SES) across the life course is associated with greater diurnal cortisol production, increased inflammatory activity and higher circulating antibodies for several pathogens, all suggesting a dampened immune response. Recent evidence suggests that DNA methylation of pro-inflammatory genes may be implicated in the biological embedding of the social environment. Methods: The present study examines the association between life-course SES and DNA methylation of candidate genes, selected on the basis of their involvement in SES-related inflammation, in the context of a genome-wide methylation study. Participants were 857 healthy individuals sampled from the EPIC Italy prospective cohort study. Results: Indicators of SES were associated with DNA methylation of genes involved in inflammation. NFATC1, in particular, was consistently found to be less methylated in individuals with low vs high SES, in a dose-dependent manner. IL1A, GPR132 and genes belonging to the MAPK family were also less methylated among individuals with low SES. In addition, associations were found between SES and CXCL2 and PTGS2, but these genes were consistently more methylated among low SES individuals. Conclusions: Our findings support the hypothesis that the social environment leaves an epigenetic signature in cells. Although the functional significance of SES-related DNA methylation is still unclear, we hypothesize that it may link SES to chronic disease ris
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