Statistics of non-linear stochastic dynamical systems under L\'evy noises by a convolution quadrature approach

This paper describes a novel numerical approach to find the statistics of the non-stationary response of scalar non-linear systems excited by L\'evy white noises. The proposed numerical procedure relies on the introduction of an integral transform of Wiener-Hopf type into the equation governing the characteristic function. Once this equation is rewritten as partial integro-differential equation, it is then solved by applying the method of convolution quadrature originally proposed by Lubich, here extended to deal with this particular integral transform. The proposed approach is relevant for two reasons: 1) Statistics of systems with several different drift terms can be handled in an efficient way, independently from the kind of white noise; 2) The particular form of Wiener-Hopf integral transform and its numerical evaluation, both introduced in this study, are generalizations of fractional integro-differential operators of potential type and Gr\"unwald-Letnikov fractional derivatives, respectively.Comment: 20 pages, 5 figure

Should reduction of increased short-term blood pressure variability be a target of antihypertensive therapy?

It has long been known that blood pressure (BP) is characterized by marked short-term fluctuations occurring within a 24-h period and also by long-term oscillations occurring over more prolonged periods of time. An increased short-term blood pressure variability (BPV) appears to importantly contribute to target organ damage and to the enhanced cardiovascular risk of hypertensive patients, over and above the effect of an increase in mean BP levels. Reducing 24-h mean BP is the main aim of antihypertensive therapy, but initial data are available that additional cardiovascular protection can be achieved by reducing BPV. However, to definitively prove the prognostic role of short-term BPV and the need for its control by treatment, evidence is still needed from intervention trials aimed at demonstrating that by reducing BPV through administration of antihypertensive drugs, a reduction in organ damage and in the rate of cardiovascular events can be obtained

Diagnostic accuracy of fecal calprotectin assay in distinguishing organic causes of chronic diarrhea from irritable bowel syndrome: a prospective study in adults and children

Fecal calprotectin (FC) has been proposed as a marker of inflammatory bowel disease (IBD), but few studies have evaluated its usefulness in patients with chronic diarrhea of various causes. We evaluated the diagnostic accuracy of a FC assay in identifying "organic" causes of chronic diarrhea in consecutive adults and children

ADVANCED ENDOSCOPIC IMAGING FOR SURVEILLANCE FOR DYSPLASIA AND COLORECTAL CANCER IN INFLAMMATORY BOWEL DISEASE: COULD THE PATHOLOGIST BE FURTHER HELPED?

Patients with inflammatory bowel disease (IBD) have an increased risk of developing intestinal cancer. The magnitude of that increased risk as well as how best to mitigate it remain a topic of ongoing investigation in the field. It is important to quantify the risk of colorectal cancer in association with IBD. The reported risk varies widely between studies. This is partly due to the different methodologies used in the studies. Because of the limitations of surveillance strategies based on the detection of dysplasia, advanced endoscopic imaging and techniques involving the detection of alterations in mucosal antigens and genetic abnormalities are being investigated. Development of new biomarkers, predicting future occurrence of colonic neoplasia may lead to more biomarker-based surveillance. There are promising results that may lead to more efficient surveillance in IBD patients and more general acceptance of its use. A multidisciplinary approach, involving in particular endoscopists and pathologists, together with a centralized patient management, could help to optimize treatments and follow-up measures, both of which could help to reduce the IBD-associated cancer risk

Relationship of choroidal thickness with pulsatile hemodynamics in essential hypertensive patients

Controversy exists about the association of choroidal thickness (CTh) with blood pressure (BP) values. There is some evidence suggesting that central hemodynamics changes are associated with microvascular disease. Our study was aimed to assess the relationships between CTh and clinic and 24-h BP and between CTh and estimated 24-h aortic pulse pressure (aPP), 24-h aortic systolic BP (aSBP), and 24-h aortic augmentation index (aAIx) in a group of hypertensive patients. We enrolled 158 hypertensive subjects (mean age 48 ± 13 years) all of which underwent evaluation of the choroidal district by Swept-Source optical coherence tomography (SS-OCT) and 24-h BP monitoring, in order to measure peripheral BP and to estimate central hemodynamic parameters. Inverse significant correlations of clinic PP, 24-h aPP, 24-h aSBP, and 24-h aAIx with thicknesses of central ring, inner ring, and outer ring of the choroid and its overall average were found. The strongest of these correlations was that relating 24-h aPP with overall average choroidal thickness (r = −.531; P <.001). When we divided the study population in subjects with 24-h aPP above and below the median value (35 mm Hg), CTh were thinner in subjects with higher values of 24-aPP as compared to those with lower ones, even after adjustment for age, and other potential confounders. The relationships of CTh with 24-h aPP remained significant also taking into account the effects of various covariates in linear multiple regression analyses. Our findings support the concept of a cross-talk between macro- and microcirculation

COLORECTAL CANCER IN PATIENTS WITH TYPE 2 DIABETES MELLITUS: PRELIMINARY RESULTS FROM AN ONGOING CASE-CONTROL STUDY

Background and Aim:Understanding the risk factors for colorectal cancer (CRC) is crucial to the development of effective strategies for its prevention. meta-analysis and epidemiological studies have already shown that type 2 diabetes mellitus (DM) is associated with an increased risk of CRC and have provided data to support a positive relationship between these diseases. Material and Methods: We retrospectively evaluated 741 consecutive caucasian patients with type 2 DM who underewnt colonoscopic screening cof CRC and followed in our tertiary referrral center in 200-208 for incidence of CRC. Patients were stratified based on gender, age, body mass index (MBI), alchool and NSAIDS assumption, family history for cancer blood glycated hemoglobin levels, hypertension, hypertrigliceridemia, age at diabetes onset and duration, treatment with insulin or other hypoglicemic drugs. A total of 257 consecutive control patients were selected from a cohort of patients followed as outpatients for thyroid diseases. Results: At a median follow-up of 132,5 months (range 33,3-175,7) 56 cases of cancer (prevalence 7,56%) occurred; among these, 14 cases of CRC were reported (prevalence 18,8%) among the diabetic patients, while only one case (prevalence 0,004%) occurred in the control group, although this difference is not statistically significant (chi-square 2,9, P=0,08). Median duration of DM to CRC diagnosis was 156 months (range 1-768). At the univariate analysis older age (p=0,001), and diabetes duration (p=0,001) were related to higher risk of cancer, while metformin seems to be protective towards cancer (p=0,058). in the subset of patients with CRC, older age (p=0,001) and diabetes duration (p=0,001) were related to higher risk of CRC, such as treatment with sulphonylureas (p=0,01). Conclusions: Our preliminbar data show that the prevalence of CRC in the cohort of patients with type 2 DM was higher compared to that from our control group, and to that from the National Tumor Register up 2010 (0,5%). Furthermore we could interestingly hypotize that sulphonylureas may play a role in CRC carcinogenesis altering the physiological insulin secretion

Fatigue in newly diagnosed acute myeloid leukaemia: General population comparison and predictive factors

Objectives: This study compared the burden of fatigue between treatment-naïve patients with newly diagnosed acute myeloid leukaemia (AML) and the general population and investigated patient factors associated with fatigue severity. Methods: Pretreatment patient-reported fatigue was assessed with the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire in a sample of 463 newly diagnosed patients with AML who were enrolled in a clinical trial. Multivariable linear regression models were used to estimate the adjusted mean differences in fatigue between patients with AML and adults from the general population (n=847) by AML disease risk categories. A clinically meaningful difference in fatigue was defined as ≥3 points. Univariable and multivariable linear regression models were used to identify sociodemographic, clinical and molecular correlates of worse fatigue in patients with AML. Results: Patients with AML reported adjusted mean fatigue scores that were 7.5 points worse than the general population (95% CI -8.6 to -6.4, p<0.001). Across AML disease risk categories, adjusted mean differences in fatigue compared with the general population ranged from 6.7 points worse (patients with favourable risk: 95% CI -8.6 to -4.8, p<0.001) to 8.9 points worse (patients with poor risk, 95% CI -10.5 to -7.2, p<0.001). Overall, 91% of patients with AML reported fatigue that was equal to or worse than the general population's median fatigue score. Higher pretreatment fatigue was independently associated with female sex, WHO performance status ≥1 and lower platelet levels. Conclusions: Patients with newly diagnosed AML reported worse fatigue than the general population, and mean differences exceeded twice the threshold for clinical significance. Our findings may help to identify patients with AML most likely to benefit from supportive care interventions to reduce fatigue