189 research outputs found
Contribution of Autonomic Reflexes to the Hyperadrenergic State in Heart Failure
Heart failure (HF) is a complex syndrome representing the clinical endpoint of many cardiovascular diseases of different etiology. Given its prevalence, incidence and social impact, a better understanding of HF pathophysiology is paramount to implement more effective anti-HF therapies. Based on left ventricle (LV) performance, HF is currently classified as follows: (1) with reduced ejection fraction (HFrEF); (2) with mid-range EF (HFmrEF); and (3) with preserved EF (HFpEF). A central tenet of HFrEF pathophysiology is adrenergic hyperactivity, featuring increased sympathetic nerve discharge and a progressive loss of rhythmical sympathetic oscillations. The role of reflex mechanisms in sustaining adrenergic abnormalities during HFrEF is increasingly well appreciated and delineated. However, the same cannot be said for patients affected by HFpEF or HFmrEF, whom also present with autonomic dysfunction. Neural mechanisms of cardiovascular regulation act as "controller units," detecting and adjusting for changes in arterial blood pressure, blood volume, and arterial concentrations of oxygen, carbon dioxide and pH, as well as for humoral factors eventually released after myocardial (or other tissue) ischemia. They do so on a beat-to-beat basis. The central dynamic integration of all these afferent signals ensures homeostasis, at rest and during states of physiological or pathophysiological stress. Thus, the net result of information gathered by each controller unit is transmitted by the autonomic branch using two different codes: intensity and rhythm of sympathetic discharges. The main scope of the present article is to (i) review the key neural mechanisms involved in cardiovascular regulation; (ii) discuss how their dysfunction accounts for the hyperadrenergic state present in certain forms of HF; and (iii) summarize how sympathetic efferent traffic reveal central integration among autonomic mechanisms under physiological and pathological conditions, with a special emphasis on pathophysiological characteristics of HF
Reactome pathway analysis from whole-blood transcriptome reveals unique characteristics of systemic sclerosis patients at the preclinical stage
ObjectiveThis study aims to characterize differential expressed pathways (DEP) in subjects with preclinical systemic sclerosis (PreSSc) characterized uniquely by Raynaud phenomenon, specific autoantibodies, and/or capillaroscopy positive for scleroderma pattern.MethodsWhole-blood samples from 33 PreSSc with clinical prospective data (baseline and after 4 years of follow-up) and 16 matched healthy controls (HC) were analyzed for global gene expression transcriptome analysis via RNA sequencing. Functional Analysis of Individual Microarray Expression method annotated Reactome individualized pathways. ANOVA analysis identified DEP whose predictive capability were tested in logistic regression models after extensive internal validation.ResultsAt 4 years, 42.4% subjects progressed (evolving PreSSc), while the others kept stable PreSSc clinical features (stable PreSSc). At baseline, out of 831 pathways, 541 DEP were significant at a false discovery rate <0.05, differentiating PreSSc versus HC with an AUROC = 0.792 ± 0.242 in regression models. Four clinical groups were identified via unsupervised clustering (HC, HC and PreSSc with HC-like features, PreSSc and HC with PreSSc-like features, and PreSSc). Biological signatures changed with disease progression while remaining unchanged in stable subjects. The magnitude of change was related to the baseline cluster, yet no DEP at baseline was predictive of progression. Disease progression was mostly related to changes in signal transduction pathways especially linked to calcium-related events and inositol 1,4,5-triphosphate metabolism.ConclusionPreSSc had distinguished Reactome pathway signatures compared to HC. Progression to definite SSc was characterized by a shift in biological fingertips. Calcium-related events promoting endothelial damage and vasculopathy may be relevant to disease progression
Use of cytobrush for bacteriological and cytological diagnosis of endometritis in mares
Background and Aim: A combined microbial and cytological examination of uterine samples is the main diagnostic method for endometritis in mares. This study aimed to describe a procedure for using the same uterine cytobrush (CB) for both bacteriological and cytological evaluation.
Materials and Methods: The procedure consists of rolling the CB onto a sterilized glass slide immediately after collection and before the transfer into a sterile saline solution. In Experiment 1, a comparison between bacteriological results of the cotton swab (CS) and CB or pellet was made in 10 mares; in Experiment 2, bacteriological and cytological results were compared between different processing methods of CB in 28 mares; in other 6 mares, a CB was processed for cytology only, to investigate the reasons for the low cellularity of the pellet.
Results: The agreement between culture results from the CB and CS was evaluated, and a comparison between the cytological data obtained by different processing methods of CB was performed. The perfect agreement between the CB and CS microbiological results was found. The described procedure enables useful diagnostic smears for cytology. Moreover, the seeding of both the tip of CB and the saline solution used for the transport produced accurate bacteriological results.
Conclusion: The protocol described in this study for the use of CB for both cytological and bacteriological analysis could be used for the diagnosis of endometritis. To maximize diagnostic sample quality, cytology slides must be prepared with meticulous care in the field to preserve cellular integrity and minimize artifacts
Hereditary angioedema: Assessing the hypothesis for underlying autonomic dysfunction
Background
Attacks of Hereditary Angioedema due to C1-inhibitor deficiency (Cl-INH-HAE) are often triggered by stressful events/hormonal changes. Objective Our study evaluates the relationship between autonomic nervous system (ANS) and contact/complement system activation.
Methods
Twenty-three HAE patients (6 males, mean age 47.5 +/- 11.4 years) during remission and 24 healthy controls (8 males, mean age 45.3 +/- 10.6 years) were studied. ECG, beat-by-beat blood pressure, respiratory activity were continuously recorded during rest (10') and 75degrees- head-up tilt (10'). C1-INH, C4, cleaved high molecular weight kininogen (cHK) were assessed; in 16 patients and 11 controls plasma catecholamines were also evaluated. Spectral analysis of heart rate variability allowed extraction of low-(LF) and high-(HF)frequency components, markers of sympathetic and vagal modulation respectively.
Results
HAE patients showed higher mean systolic arterial pressure (SAP) than controls during both rest and tilt. Tilt induced a significant increase in SAP and its variability only in controls. Although sympathetic modulation (LFnu) increased significantly with tilt in both groups, LF/HF ratio, index of sympathovagal balance, increased significantly only in controls. At rest HAE patients showed higher noradrenaline values (301.4 +/- 132.9 pg/ml vs 210.5 +/- 89.6 pg/ml, p = 0.05). Moreover, in patients tilt was associated with a significant increase in cHK, marker of contact system activation (49.5 +/- 7.5% after T vs 47.1 +/- 7.8% at R, p = 0.01).
Conclusions
Our data are consistent with altered ANS modulation in HAE patients, i.e. increased sympathetic activation at rest and blunted response to orthostatic challenge. Tilt test-induced increased HK cleavage suggests a link between stress and bradykinin production
RNA Editing Genes Associated with Extreme Old Age in Humans and with Lifespan in C. elegans
The strong familiality of living to extreme ages suggests that human longevity is genetically regulated. The majority of genes found thus far to be associated with longevity primarily function in lipoprotein metabolism and insulin/IGF-1 signaling. There are likely many more genetic modifiers of human longevity that remain to be discovered.Here, we first show that 18 single nucleotide polymorphisms (SNPs) in the RNA editing genes ADARB1 and ADARB2 are associated with extreme old age in a U.S. based study of centenarians, the New England Centenarian Study. We describe replications of these findings in three independently conducted centenarian studies with different genetic backgrounds (Italian, Ashkenazi Jewish and Japanese) that collectively support an association of ADARB1 and ADARB2 with longevity. Some SNPs in ADARB2 replicate consistently in the four populations and suggest a strong effect that is independent of the different genetic backgrounds and environments. To evaluate the functional association of these genes with lifespan, we demonstrate that inactivation of their orthologues adr-1 and adr-2 in C. elegans reduces median survival by 50%. We further demonstrate that inactivation of the argonaute gene, rde-1, a critical regulator of RNA interference, completely restores lifespan to normal levels in the context of adr-1 and adr-2 loss of function.Our results suggest that RNA editors may be an important regulator of aging in humans and that, when evaluated in C. elegans, this pathway may interact with the RNA interference machinery to regulate lifespan
Signatures of the Preagricultural Peopling Processes in Sub-Saharan Africa as Revealed by the Phylogeography of Early Y Chromosome Lineages
Abstract The study of Y chromosome variation has helped reconstruct demographic events associated with the spread of languages, agriculture, and pastoralism in sub-Saharan Africa, but little attention has been given to the early history of the continent. In order to overcome this lack of knowledge, we carried out a phylogeographic analysis of haplogroups A and B in a broad data set of sub-Saharan populations. These two lineages are particularly suitable for this objective because they are the two most deeply rooted branches of the Y chromosome genealogy. Their distribution is almost exclusively restricted to sub-Saharan Africa where their frequency peaks at 65% in groups of foragers. The combined high-resolution single nucleotide polymorphism analysis with short tandem repeats variation of their subclades reveals strong geographic and population structure for both haplogroups. This has allowed us to identify specific lineages related to regional preagricultural dynamics in different areas of sub-Saharan Africa. In addition, we observed signatures of relatively recent contact, both among Pygmies and between them and Khoisan speaker groups from southern Africa, thus contributing to the understanding of the complex evolutionary relationships among African hunter-gatherers. Finally, by revising the phylogeography of the very early human Y chromosome lineages, we have obtained support for the role of southern Africa as a sink, rather than a source, of the first migrations of modern humans from eastern and central parts of the continent. These results open new perspectives on the early history of Homo sapiens in Africa, with particular attention to areas of the continent where human fossil remains and archaeological data are scant
Structure and Morphology of Silver Nanoparticles on the (111) Surface of Cerium Oxide
The structure of Ag nanoparticles of different size, supported on the cerium oxide (111) surface, was investigated by X-ray absorption fine structure at the Ag K-edge. The results of the data analysis in the near and extended energy range are interpreted with the help of the results obtained by X-ray photoelectron spectroscopy and scanning tunneling microscopy measurements and allow to obtain a detailed atomic scale description of the model system investigated. The Ag nanoparticles have an average size of a few tens of angstroms, which increases with increasing deposited Ag amount. The nanoparticles show a slight tendency to nucleate at the step edges between different cerium oxide layers and they have a face centered cubic structure with an Ag-Ag interatomic distance contracted by 3-4% with respect to the bulk value. The interatomic distance contraction is mainly ascribed to dimensionality induced effects, while epitaxial effects have a minor role. The presence of Ag-O bonds at the interface between the nanoparticles and the supporting oxide is also detected. The Ag-O interatomic distance decreases with decreasing nanoparticle size
Oral ondansetron versus domperidone for acute gastroenteritis in pediatric emergency departments: Multicenter double blind randomized controlled trial
The use of antiemetics for vomiting in acute gastroenteritis in children is still a matter of debate. We conducted a double-blind randomized trial to evaluate whether a single oral dose of ondansetron vs domperidone or placebo improves outcomes in children with gastroenteritis. After failure of initial oral rehydration administration, children aged 1-6 years admitted for gastroenteritis to the pediatric emergency departments of 15 hospitals in Italy were randomized to receive one oral dose of ondansetron (0.15 mg/kg) or domperidone (0.5 mg/kg) or placebo. The primary outcome was the percentage of children receiving nasogastric or intravenous rehydration. A p value of 0.014 was used to indicate statistical significance (and 98.6% CI were calculated) as a result of having carried out two interim analyses. 1,313 children were eligible for the first attempt with oral rehydration solution, which was successful for 832 (63.4%); 356 underwent randomization (the parents of 125 children did not give consent): 118 to placebo, 119 to domperidone, and 119 to ondansetron. Fourteen (11.8%) needed intravenous rehydration in the ondansetron group vs 30 (25.2%) and 34 (28.8%) in the domperidone and placebo groups, respectively. Ondansetron reduced the risk of intravenous rehydration by over 50%, both vs placebo (RR 0.41, 98.6% CI 0.20-0.83) and domperidone (RR 0.47, 98.6% CI 0.23-0.97). No differences for adverse events were seen among groups. In a context of emergency care, 6 out of 10 children aged 1-6 years with vomiting due to gastroenteritis and without severe dehydration can be managed effectively with administration of oral rehydration solution alone. In children who fail oral rehydration, a single oral dose of ondansetron reduces the need for intravenous rehydration and the percentage of children who continue to vomit, thereby facilitating the success of oral rehydration. Domperidone was not effective for the symptomatic treatment of vomiting during acute gastroenteritis
How do cardiologists select patients for dual antiplatelet therapy continuation beyond 1 year after a myocardial infarction? Insights from the EYESHOT Post-MI Study
Background: Current guidelines suggest to consider dual antiplatelet therapy (DAPT) continuation for longer than 12 months in selected patients with myocardial infarction (MI). Hypothesis: We sought to assess the criteria used by cardiologists in daily practice to select patients with a history of MI eligible for DAPT continuation beyond 1 year. Methods: We analyzed data from the EYESHOT Post-MI, a prospective, observational, nationwide study aimed to evaluate the management of patients presenting to cardiologists 1 to 3 years from the last MI event. Results: Out of the 1633 post-MI patients enrolled in the study between March and December 2017, 557 (34.1%) were on DAPT at the time of enrolment, and 450 (27.6%) were prescribed DAPT after cardiologist assessment. At multivariate analyses, a percutaneous coronary intervention (PCI) with multiple stents and the presence of peripheral artery disease (PAD) resulted as independent predictors of DAPT continuation, while atrial fibrillation was the only independent predictor of DAPT interruption for patients both at the second and the third year from MI at enrolment and the time of discharge/end of the visit. Conclusions: Risk scores recommended by current guidelines for guiding decisions on DAPT duration are underused and misused in clinical practice. A PCI with multiple stents and a history of PAD resulted as the clinical variables more frequently associated with DAPT continuation beyond 1 year from the index MI
Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions
We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe
- …