924 research outputs found
Validation of a method for the determination of the sensible-heat flux with Sodar data in free convection cases
A simple method to determine the value of the ground sensible-heat flux using Sodar data is presented and validated. The measurement of the variance of
the wind velocity components gives us an estimate of the intensity of the atmospheric turbulence; the local value of variance of the vertical wind velocity s2w depends on the
efficiency of thermal and mechanical turbulence production. The portion of the atmospheric boundary layer, where turbulent kinetic energy is prevalently produced by buoyancy forces, is characterised by profiles of s3w Oz and of (sensible-) heat flux which decrease linearly with height. The extrapolation to the ground of the former
profile gives an estimate of the value of sensible-heat flux at the surface. The validation of the results is performed by comparison of the energy involved in the
development of convective episodes calculated, over the same time interval, from sensible-heat flux at the surface with that derived from potential temperature profiles relative to two successive radio soundings. When perturbative processes like, for example, rise up of breezes, are absent, the estimates of energies are in
excellent agreement, being the angular coefficient of regression line 1.01 and the linear correlation coefficient 0.93
Delphi consensus on the current clinical and therapeutic knowledge on Anderson-Fabry disease
BACKGROUND: Management of Anderson-Fabry disease (AFD) is contentious, particularly regarding enzyme replacement therapy (ERT). We report results of a Delphi consensus panel on AFD management.
METHODS: A survey to gauge consensus among AFD experts was distributed online and responses were analysed. Statements on: 1) diagnosis; 2) when starting ERT; 3) management of ERT infusion and adverse reactions; and 4) follow-up/monitoring response to therapy and progression of disease were included. Responses without consensus were discussed with an enlarged panel and modified to reach consensus.
RESULTS: 15 experts responded to the survey. After plenary discussion among the enlarged panel, consensus was reached on most statements. Key points were the use of a target organ biopsy to show Gb3 deposits in symptomatic women with negative molecular analysis, the need for ERT in symptomatic women and in all patients with persistent signs and symptoms±organ damage. It was agreed to assess vital signs before ERT administration and use a 0.2μL filter on infusion to reduce the risk of adverse reactions, that serum should be drawn prior to the first infusion for anti-agalsidase antibody analysis to have a baseline value if a subsequent adverse reaction appears, and that pre-medication is required in those with prior infusion reactions. Holter ECG monitoring, cardiac and brain MRI, renal parameters, and abdominal ultrasound were considered important for the assessment of disease progression and response at ERT.
CONCLUSIONS: This consensus supplies guidance to healthcare providers on best practice in the management of patients with AFD and indicates a need for more guidanc
Infarct-like myocarditis with coronary vasculitis and aneurysm formation caused by epstein–barr virus infection
Myocardial infection by Epstein–Barr virus (EBV) may manifest with inflammatory cardiomyopathy, coronary syndrome X, and rarely with infarct-like myocarditis. The aim of the report is to describe a case of myocardial EBV infection causing acute myocarditis with heart failure, necrotizing coronary vasculitis, and multiple left ventricular (LV) aneurysms. A 67-year-old woman presented with fever, chest pain, and heart failure. She underwent non-invasive cardiac studies including electrocardiography, 2D-echocardiography, cardiac magnetic resonance, hematochemical exams with Troponin T determination, and invasive studies including cardiac catheterization, coronary angiography, and LV endomyocardial biopsy. Five endomyocardial samples were processed for histology and immunohistochemistry for inflammatory cells characterization and detection of viral antigens. Two additional frozen samples were evaluated by real-time polymerase chain reaction for the presence of cardiotropic viral genomes. Routine laboratory tests revealed the presence of elevated white blood cells (17 000 103/μL) and increased Troponin T. Electrocardiogram showed sinus tachycardia with ST elevation in V2–V5. Two-dimensional echocardiography showed normal LV dimension with reduced LV contractility (LVEF = 40%) with mild pericardial effusion. Cardiac magnetic resonance revealed the presence of a micro-aneurism in the inferior LV wall, a diffuse oedematous imbibition of LV myocardium suggested by hyper-intensity of T2 mapping, and increased fibrosis as suggested by areas of late gadolinium enhancement signals. Coronary arteries were normal while several micro-aneurysms were observed at LV angiography. At histology, a lymphocytic myocarditis with necrotizing coronary vasculitis sustained by a positive real-time polymerase chain reaction for EBV, detectable in cardiomyocytes and inflamed intramural vessels by positive immunohistochemistry for EBV latent membrane protein 1 antigen, was observed. Myocardial EBV infection is an unusual cause of acute heart failure and cardiac aneurysms, increasing the risk of electrical instability, cardiac perforation, and sudden death
Nuclear receptors PPARβ/δ and PPARα direct distinct metabolic regulatory programs in the mouse heart
In the diabetic heart, chronic activation of the PPARα pathway drives excessive fatty acid (FA) oxidation, lipid accumulation, reduced glucose utilization, and cardiomyopathy. The related nuclear receptor, PPARβ/δ, is also highly expressed in the heart, yet its function has not been fully delineated. To address its role in myocardial metabolism, we generated transgenic mice with cardiac-specific expression of PPARβ/δ, driven by the myosin heavy chain (MHC-PPARβ/δ mice). In striking contrast to MHC-PPARα mice, MHC-PPARβ/δ mice had increased myocardial glucose utilization, did not accumulate myocardial lipid, and had normal cardiac function. Consistent with these observed metabolic phenotypes, we found that expression of genes involved in cellular FA transport were activated by PPARα but not by PPARβ/δ. Conversely, cardiac glucose transport and glycolytic genes were activated in MHC-PPARβ/δ mice, but repressed in MHC-PPARα mice. In reporter assays, we showed that PPARβ/δ and PPARα exerted differential transcriptional control of the GLUT4 promoter, which may explain the observed isotype-specific effects on glucose uptake. Furthermore, myocardial injury due to ischemia/reperfusion injury was significantly reduced in the MHC-PPARβ/δ mice compared with control or MHC-PPARα mice, consistent with an increased capacity for myocardial glucose utilization. These results demonstrate that PPARα and PPARβ/δ drive distinct cardiac metabolic regulatory programs and identify PPARβ/δ as a potential target for metabolic modulation therapy aimed at cardiac dysfunction caused by diabetes and ischemia
Hypoxia and inflammation as a consequence of β-fibril accumulation. A perspective view for new potential therapeutic targets
Amyloidoses are heterogeneous diseases that result from the deposition of toxic insoluble β-sheet fibrillar protein aggregates in different tissues. The cascade of molecular events leading to amyloidoses and to the related clinical manifestations is not completely understood. Nevertheless, it is known that tissue damage associated to this disease involves alteration of tissue architecture, interaction with cell surface receptors, inflammation elicited by the amyloid protein deposition, oxidative stress, and apoptosis. However, another important aspect to consider is that systemic protein massive deposition not only subverts tissue architecture but also determines a progressive cellular hypertrophy and dilation of the extracellular space enlarging the volume of the organ. Such an alteration increases the distance between cells and vessels with a drop in pO2 that, in turn, causes both necrotic cell death and activation of the hypoxia transcription factor HIF-1α. Herewith, we propose the hypothesis that both cell death and hypoxia represent two important events for the pathogenesis of damage and progression of amyloidoses. In fact, molecules released by necrotic cells activate inflammatory cells from one side while binding to HIF-1α-dependent membrane receptors expressed on hypoxic parenchymal cells on the other side. This latter event generates a signaling cascade triggering NFκB activation and chronic inflammation. Finally, we also suggest that this scenario, once proved and detailed, might suggest important targets for new therapeutic interventions
Myocarditis and intramural coronary vasculitis in polyarteritis nodosa: an unusual treatable form of heart failure
We describe an uncommon cardiac presentation of polyarteritis nodosa. A 68-year-old woman, with a history of fatigue, weight loss, and myalgia of the lower extremities, was admitted for congestive heart failure. Coronary arteries were normal. Endomyocardial biopsy showed active lymphocytic myocarditis with associated intramural small vessels necrotizing vasculitis. The overexpression of TLR-4 and the negativity for myocardial viruses suggested an immune mediated mechanism of cardiac damage. These histologic findings associated to weight loss >4 kg not due to dieting or other factors, myalgias, and polyneuropathy, were consistent with the diagnosis of polyarteritis nodosa. Immunosuppressive treatment, consisting of cyclophosphamide and prednisolone, led to a significant improvement of cardiac function. Polyarteritis nodosa can be the cause of unexplained heart failure due to myocarditis and intramural vessels vasculitis. Its recognition is crucial to obtain a cardiac recovery with a tailored immunosuppressive treatment
Mutational Landscape of Bone Marrow CD19 and CD138 Cells in Waldenström Macroglobulinemia (WM) and IgM Monoclonal Gammopathy of Undetermined Significance (IgM MGUS)
Despite recurrent and activating mutations, including MYD88, CXCR4, ARID1A, KMT2D, and CD79B were identified, the genetic basis for Waldenström’s Macroglobulinemia (WM) and the risk of progression of IgM MGUS to WM remain to be fully elucidated.
We investigated the mutation status of WM (n=8), sWM (n=7), and IgM MGUS (n=5) patients, by performing high-throughput targeted AmpliSeq NGS on 117 target genes.
We detected the classic mutation MYD88L265P in 93% of WM/sWM and in 60% of IgM MGUS patients. The CXCR4S338Ter mutation was identified in 26% of WM/sWM patients, whereas it was undetectable in IgM MGUS subjects.
Interestingly, we identified new mutated genes, including WNK2 somatic mutations affecting 46% of WM/sWM patients, for which a recurrent allelic variant (V1635Ter) was observed in this cohort, and BCL9 with a frameshift variant (P516Lfs) in 26% of WM/sWM and in one IgM MGUS patient.
Moreover, sequencing evaluation revealed recurrently frameshift or missense mutations involving NFKB2 (L473Afs), PTPN13 (P1546Tfs), CARD11 (S622del), KMT2C (I823T), and ATM in WM and IgM MGUS patients
Fabry cardiomyopathy: Gb3-induced auto-reactive panmyocarditis requiring heart transplantation
Resistance to enzyme replacement therapy (ERT) is a major therapeutic challenge in Fabry disease (FD). Recent reports attribute to immune-mediated inflammation a main role in promoting disease progression and resistance to ERT. Aim of the study is to report a Gb3-induced auto-reactive panmyocarditis causing inefficacy of ERT and severe electrical instability, which required cardiac transplantation. Examining the explanted heart from a 57-year-old man with FD cardiomyopathy (CM) on 3-year ERT presenting incoming ventricular fibrillation, we documented a severe virus-negative myocarditis extended to cardiomyocytes, intramural coronary vessels, conduction tissue, and subepicardial ganglia. Serology was positive for anti-Gb3, anti-heart, and anti-myosin antibodies. In vitro Gb3 stimulation of patient's peripheral blood mononuclear cells (PBMC) induced high amount production of inflammatory cytokine IL1-\u3b2, IL-6, IL-8, and TNF-\u3b1. PBMC were stained using the monoclonal antibodies CD3-V500, CD4-V450, CD8-APCcy7, CD45RO-PerCPcy5.5 and CD27-FITC from BD Biosciences and CD56-PC7 from Bekman Coulter. The phenotypic analysis of PBMC showed a lower frequency of CD8 (9.2%) vs. 19.3% and NKT cells (1.6% vs. 2.4%) in Fabry patient respect to healthy donor, suggesting a possible homing to peripheral tissues. A Gb3-induced auto-reactive myocarditis is suggested as a possible cause of FDCM progression and ERT resistance. Immune-mediated inflammation of systemic Fabry cells may coexist and be controlled by implemental immunosuppressive therapy
The role of endomyocardial biopsy in the management of cardiovascular disease: a scientific statement from the American Heart Association, the American College of Cardiology, and the European Society of Cardiology
The role of endomyocardial biopsy (EMB) in the diagnosis and treatment of adult and pediatric cardiovascular disease remains controversial, and the practice varies widely even among cardiovascular centers of excellence. A need for EMB exists because specific myocardial disorders that have unique prognoses and treatment are seldom diagnosed by noninvasive testing.1 Informed clinical decision making that weighs the risks of EMB against the incremental diagnostic, prognostic, and therapeutic value of the procedure is especially challenging for nonspecialists because the relevant published literature is usually cited according to specific cardiac diseases, which are only diagnosed after EM
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