153 research outputs found

    Combining permutation tests to rank systemically important banks

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    In this work we propose the use of a nonparametric procedure to investigate the relationship between the Regulator’s Global Systemically Important Banks (G-SIBs) classification and the equity-based systemic risk measures. The proposed procedure combines several permutation tests to investigate the equality of the multivariate distribution of two groups and assumes only the hypothesis of exchangeability of variables. In our novel approach, the weights used in the combination of tests are obtained using the Particle Swarm Optimization heuristic and quantify the informativeness about the selection. Finally, the p value of the combined test measures the reliability of the result. Empirical results about the selection of G-SIBs show how considering the systematic ( ), stress ( CoVaR) and connectedness components (in–out connection) of systemic risk cover more than 70% of weight in all the considered years

    A nonparametric measure of riskness in financial systems

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    In the literature of risk analysis different synthetic indices are artificially built and in this work we propose to use the combination statistical procedure of theunivariate indices proposed by V-lab. The combination technique may also be considered to perform nonparametric inference. So we propose to highlight systemic risk in a network of companies performing a nonparametric test to reveal heterogeneity behaviour; in this case one ranking is used to create different behavioural groups

    The Contribution of -Synuclein Spreading to Parkinson’s Disease Synaptopathy

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    Synaptopathies are diseases with synapse defects as shared pathogenic features, encompassing neurodegenerative disorders such as Parkinson’s disease (PD). In sporadic PD, the most common age-related neurodegenerative movement disorder, nigrostriatal dopaminergic deficits are responsible for the onset of motor symptoms that have been related to -synuclein deposition at synaptic sites. Indeed, -synuclein accumulation can impair synaptic dopamine release and induces the death of nigrostriatal neurons. While in physiological conditions the protein can interact with and modulate synaptic vesicle proteins and membranes, numerous experimental evidences have confirmed that its pathological aggregation can compromise correct neuronal functioning. In addition, recent findings indicate that -synuclein pathology spreads into the brain and can affect the peripheral autonomic and somatic nervous system. Indeed, monomeric, oligomeric, and fibrillary -synuclein can move from cell to cell and can trigger the aggregation of the endogenous protein in recipient neurons. This novel “prion-like” behavior could further contribute to synaptic failure in PD and other synucleinopathies. This review describes the major findings supporting the occurrence of -synuclein pathology propagation in PD and discusses how this phenomenon could induce or contribute to synaptic injury and degeneration

    Opposing Roles for NF-κB/Rel Factors p65 and c-Rel in the Modulation of Neuron Survival Elicited by Glutamate and Interleukin-1β

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    The nuclear transcription factors NF-kappaB/Rel have been shown to function as key regulators of either cell death or survival in neuronal cells. Here, we investigated whether selective activation of diverse NF-kappaB/Rel family members might lead to distinct effects on neuron viability. In both cultured rat cerebellar granule cells and mouse hippocampal slices, we examined NF-kappaB/Rel activation induced by two opposing modulators of cell viability: 1) interleukin-1beta (IL-1beta), which promotes neuron survival and 2) glutamate, which can elicit toxicity. IL-1beta produced a prolonged stimulation of NF-kappaB/Rel factors by inducing both IkappaBalpha and IkappaBbeta degradation. Glutamate produced a delayed and transient activation of NF-kappaB/Rel, which was associated with a brief loss of IkappaBalpha. Moreover, IL-1beta activated the p50, p65, and c-Rel subunits of NF-kappaB/Rel, whereas glutamate activated only the p50 and p65 proteins. The inhibition of NF-kappaB/Rel protein expression by antisense oligonucleotides in cerebellar granule cells showed that p65 was involved in glutamate-mediated cell death, whereas c-Rel was essential for IL-1beta-preserved cell survival. Furthermore, the depletion of c-Rel in cultured neurons as well as in the hippocampus from the c-Rel(-/-) mouse converted the IL-1beta effect into toxicity. These findings suggest that, within a single neuron, the balance between cell death and survival in response to external stimuli may rely on the activation of distinct NF-kappaB/Rel proteins

    Mutations in KCNK4 that Affect Gating Cause a Recognizable Neurodevelopmental Syndrome

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    Aberrant activation or inhibition of potassium (K+) currents across the plasma membrane of cells has been causally linked to altered neurotransmission, cardiac arrhythmias, endocrine dysfunction, and (more rarely) perturbed developmental processes. The K+ channel subfamily K member 4 (KCNK4), also known as TRAAK (TWIK-related arachidonic acid-stimulated K+ channel), belongs to the mechano-gated ion channels of the TRAAK/TREK subfamily of two-pore-domain (K2P) K+ channels. While K2P channels are well known to contribute to the resting membrane potential and cellular excitability, their involvement in pathophysiological processes remains largely uncharacterized. We report that de novo missense mutations in KCNK4 cause a recognizable syndrome with a distinctive facial gestalt, for which we propose the acronym FHEIG (facial dysmorphism, hypertrichosis, epilepsy, intellectual disability/developmental delay, and gingival overgrowth). Patch-clamp analyses documented a significant gain of function of the identified KCNK4 channel mutants basally and impaired sensitivity to mechanical stimulation and arachidonic acid. Co-expression experiments indicated a dominant behavior of the disease-causing mutations. Molecular dynamics simulations consistently indicated that mutations favor sealing of the lateral intramembrane fenestration that has been proposed to negatively control K+ flow by allowing lipid access to the central cavity of the channel. Overall, our findings illustrate the pleiotropic effect of dysregulated KCNK4 function and provide support to the hypothesis of a gating mechanism based on the lateral fenestrations of K2P channels

    Myocardial infarction with nonobstructive coronary arteries: from pathophysiology to therapeutic strategies

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    : Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a heterogeneous group of clinical entities characterized by clinical evidence of acute myocardial infarction (AMI) with normal or near-normal coronary arteries on coronary angiography (stenosis < 50%) and without an over the alternative diagnosis for the acute presentation. Its prevalence ranges from 6% to 11% among all patients with AMI, with a predominance of young, nonwhite females with fewer traditional risks than those with an obstructive coronary artery disease (MI-CAD). MINOCA can be due to either epicardial causes such as rupture or fissuring of unstable nonobstructive atherosclerotic plaque, coronary artery spasm, spontaneous coronary dissection and cardioembolism in-situ or microvascular causes. Besides, also type-2 AMI due to supply-demand mismatch and Takotsubo syndrome must be considered as a possible MINOCA cause. Because of the complex etiology and a limited amount of evidence, there is still some confusion around the management and treatment of these patients. Therefore, the key focus of this condition is to identify the underlying individual mechanisms to achieve patient-specific treatments. Clinical history, electrocardiogram, echocardiography, and coronary angiography represent the first-level diagnostic investigations, but coronary imaging with intravascular ultrasound and optical coherent tomography, coronary physiology testing, and cardiac magnetic resonance imaging offer additional information to understand the underlying cause of MINOCA. Although the prognosis is slightly better compared with MI-CAD patients, MINOCA is not always benign and depends on the etiopathology. This review analyzes all possible pathophysiological mechanisms that could lead to MINOCA and provides the most specific and appropriate therapeutic approach in each scenario

    Body mass index rather than the phenotype impacts precocious ultrasound cardiovascular risk markers in polycystic ovary syndrome

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    Objective Research into cardiovascular disease (CV) prevention has demonstrated a variety of ultrasound (US) markers predicting risk in the general population but which have been scarcely used for polycystic ovary syndrome (PCOS). Obesity is a major factor contributing to CV disease in the general population, and it is highly prevalent in PCOS. However, it is still unclear how much risk is attributable to hyperandrogenism. This study evaluates the most promising US CV risk markers in PCOS and compares them between different PCOS phenotypes and BMI values. Design Women fulfilling the Rotterdam criteria for PCOS were recruited from our outpatient clinic for this cross-sectional study. Methods Participants (n\u2009=\u2009102) aged 38.9 \ub1 7.4 years were stratified into the four PCOS phenotypes and the three BMI classes (normal-weight, overweight, obese). They were assessed for clinical and biochemical parameters together with the following US markers: coronary intima-media thickness (cIMT), flow-mediated vascular dilation (FMD), nitroglycerine-induced dilation (NTG), and epicardial fat thickness (EFT). Results There was no statistical difference among the four phenotypes in terms of cIMT, FMD, NTG or EFT, however all the US parameters except NTG showed significant differences among the three BMI classes. Adjusting for confounding factors in multiple regression analyses, EFT retained the greatest direct correlation with BMI and cIMT remained directly correlated but to a lesser degree. Conclusions This study showed that obesity rather than the hyperandrogenic phenotype negatively impacts precocious US CV risk markers in PCOS. In addition, EFT showed the strongest association with BMI, highlighting its potential for estimating CV risk in PCOS

    Mucinous and Signet-Ring Cell Colonic Adenocarcinoma in Inflammatory Bowel Disease: A Case-Control Study

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    Simple Summary Chronic active inflammation is a known risk factor for colorectal cancer (CRC) in inflammatory bowel disease (IBD), while the adenoma-carcinoma sequence appears to be associated with sporadic CRC. In the general population, mucinous and signet-ring cell adenocarcinomas are characterized by a worse prognosis. In IBD, a higher frequency of these CRC histotypes has been reported. In the present study, we investigated the frequency and characteristics of mucinous and signet-ring cell adenocarcinomas in patients with IBD versus age-matched non-IBD Controls. CRC was more frequently represented by mucinous/signet-ring cell adenocarcinoma in IBD than in Controls. In rectal CRC, there was a higher proportion of mucinous/signet-ring cell adenocarcinoma vs. standard adenocarcinoma in IBD but not in non-IBD Controls. No risk factors for these two CRC histotypes were identified in IBD. Present findings support that the frequency of mucinous/signet-ring cell colorectal adenocarcinoma is higher in IBD, being associated with rectal involvement of CRC. A higher frequency of mucinous and signet-ring cell colonic adenocarcinoma has been reported in inflammatory bowel disease (IBD). The primary aim was to investigate the frequency of mucinous and signet-ring cell colorectal adenocarcinoma in patients with IBD (Cases) versus age-matched non-IBD Controls. The secondary aims were to compare the characteristics of these two histotypes of colorectal cancer (CRC) in IBD patients vs. Controls and to search for specific risk factors in IBD. In a case-control study, all IBD patients with CRC diagnosed from 2000 to 2022 were enrolled and matched for age (1:2) with non-IBD Controls with CRC. The study population included 120 CRC patients (40 IBD, 80 Controls). In IBD, CRC included standard adenocarcinoma in 23 (57.5%) patients mucinous/signet-ring cell adenocarcinoma in 17 (42.5%) patients. The proportion of mucinous/signet-ring cell adenocarcinoma was higher in IBD than in Controls (17 [42.5%] vs. 18 [22.5%]; p = 0.03). In rectal CRC, the proportion of mucinous/signet-ring cell adenocarcinoma was higher than standard adenocarcinoma in IBD (8 [47.1%] vs. 4 [17.4%]; p = 0.04) but not in Controls (4 [22.2%] vs. 20 [32.2%]; p = 0.59). In rectal CRC, the proportion of these two histotypes was higher in Cases than in Controls (8/12 [66.6%] vs. 4/24 [16.6%]; p = 0.008), with no risk factors identified in IBD. CRC was more frequently represented by mucinous/signet-ring cell adenocarcinoma in IBD than in age-matched non-IBD Controls. In IBD, these two CRC histotypes were more frequent in the rectum
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