77 research outputs found
Non-Perturbative Renormalisation and Kaon Physics
A general review is presented on the problem of non perturbative computation
of the transition amplitude.Comment: 8 pages, Latex, uses espcrc2.sty, Talk given at LATTICE9
ECMO as Bridge to Heart Transplantation
Extracorporeal membrane oxygenation (ECMO) is increasingly employed to support patients affected by refractory cardiogenic shock. When patients cannot be weaned from ECMO because of severe heart dysfunction, heart transplantation (HTx) or implantation of a durable mechanical circulatory support should be considered. Traditionally, the use of ECMO as a direct bridge to HTx was burdened by high mortality. However, during these last years, the widespread employment of ECMO increased centers’ experience in the management of this device, and new allocation policies provided the highest priority level for ECMO HTx candidates. Therefore, these factors could have mitigated the negative outcomes previously reported. The aim of this chapter is to describe the role of ECMO as a direct bridge to HTx, analyzing results of this strategy, and how to determine candidacy and risk stratification among the severely ill population of patients supported by this mechanical circulatory support
Management of untreatable ventricular arrhythmias during pharmacologic challenges with sodium channel blockers for suspected Brugada syndrome
Pharmacologic challenge with sodium channel blockers is part of the diagnostic workout in patients with suspected Brugada syndrome. The test is overall considered safe but both ajmaline and flecainide detain well known pro-arrhythmic properties. Moreover, the treatment of patients with life-threatening arrhythmias during these diagnostic procedures is not well defined. Current consensus guidelines suggest to adopt cautious protocols interrupting the sodium channel blockers as soon as any ECG alteration appears. Nevertheless, the risk of life-threatening arrhythmias persists, even adopting a safe and cautious protocol and in absence of major arrhythmic risk factors. The authors revise the main published case studies of sodium channel blockers challenge in adults and in children, and summarize three cases of untreatable ventricular arrhythmias discussing their management. In particular, the role of advanced cardiopulmonary resuscitation with extra-corporeal membrane oxygenation is stressed as it can reveal to be the only reliable lifesaving facility in prolonged cardiac arrest
Does the distance between residency and implanting center affect the outcome of patients supported by left ventricular assist devices? A multicenter Italian study on radial mechanically assisted circulatory support (MIRAMACS) analysis
Background Patients with LVAD require continuous monitoring and care, and since Implanting Centers (ICs) are more experienced in managing LVAD patients than other healthcare facilities, the distance between patient residency and IC could negatively affect the outcomes. Methods Data of patients discharged after receiving an LVAD implantation between 2010 and 2021 collected from the MIRAMACS database were retrospectively analyzed. The population was divided into two groups: A (n = 175) and B (n = 141), according to the distance between patient residency and IC 90 miles. The primary endpoint was freedom from Adverse Events (AEs), a composite outcome composed of death, cerebrovascular accident, hospital admission because of GI bleeding, infection, pump thrombosis, and right ventricular failure. Secondary endpoints were incidences of mortality and complications. All patients were followed-up regularly, according to participating center protocols. Results Baseline clinical characteristics and indications for LVAD did not differ between the two groups. The mean duration of support was 25.5 +/- 21 months for Group A and 25.7 +/- 20 months for Group B (p = 0.79). At 3 years, freedom from AEs was similar between Group A and Group B (p = 0.36), and there were no differences in rates of mortality and LVAD-related complications. Conclusions Distance from the IC does not represent a barrier to successful outcomes as long as regular and continuous follow-up is provided
Technology and technique for left ventricular assist device optimization: A Bi-Tech solution
Background We investigated the synergistic effect of the new cone-bearing design of Jarvik 2000 (Jarvik Heart Inc., NY) together with a minimally-invasive approach to outcomes of LVAD patients. Methods We retrospectively reviewed all patients from 5 institutions involved in the Jarvik 2000 Italian Registry, from October 2008 to October 2016. Patients were divided into three groups according to pump design and implantation technique: pin-bearing design and conventional approach (Group 1); cone-bearing and conventional approach (Group 2); cone-bearing and minimally-invasive implantation (Group 3). Results A total of 150 adult patients with end-stage heart failure were enrolled: 26 subjects in Group 1, 74 in Group 2, and 50 in Group 3. Nineteen patients (73%) in Group 1, 51 (69%) in Group 2, and 36 (72%) in Group 3 were discharged. During follow-up, 22 patients underwent transplantation, while in 3 patients the LVAD was explanted. The overall 1-year survival was 58 +/- 10%, 64 +/- 6%, and 74% +/- 7% in Groups 1, 2, and 3, respectively (p = 0.034). The competing-risks-adjusted cumulative incidence rate for adverse events was 42.1 [27-62.7] per 100 patient-years in Group 1, 35.4 [25.3-48.2] in Group 2, and 22.1 [12.4-36.4] in Group 3 (p = 0.046 for Group 1 vs. 3). Conclusions The association of the modern cone-bearing configuration of Jarvik 2000 and minimally invasive surgery improved survival and minimized the risk for cardiovascular events, as a result of combining technology and technique
Non Linear Realizations of in the MSSM: Model Independent Analysis and of Bosons
We perform a model-independent analysis of the spontaneously broken phase of
an supersymmetric gauge theory, by using a non-linear
parametrization of the Goldstone sector of the theory. The non-linear variables
correspond to an superfield matrix in terms of which a non-linear
Lagrangian can be constructed, and the pattern of supersymmetry breaking
investigated. The supersymmetric order parameter is the V.E.V. of the neutral
pseudo-Goldstone boson. Some applications of this technique are considered, in
relation to the minimal supersymmetric standard model, and to determine the
of the -bosons in the limit of large top mass.Comment: 11 page
Hypermagnetic Knots, Chern-Simons Waves and the Baryon Asymmetry
At finite hyperconductivity and finite fermionic density the flux lines of
long range hypermagnetic fields may not have a topologically trivial structure.
The combined evolution of the chemical potentials and of pseudoscalar fields
(like the axial Higgs), possibly present for temperatures in the TeV range, can
twist the hypercharge flux lines, producing, ultimately, hypermagnetic knots
(HK). The dynamical features of the HK depend upon the various particle physics
parameters of the model (pseudoscalar masses and couplings, strength of the
electroweak phase transition, hyperconductivity of the plasma) and upon the
magnitude of the primordial flux sitting in topologically trivial
configurations of the hypermagnetic field. We study different cosmological
scenarios where HK can be generated. We argue that the fermionic number sitting
in HK can be released producing a seed for the Baryon Asymmetry of the Universe
(BAU) provided the typical scale of the knot is larger than the diffusivity
length scale. We derive constraints on the primordial hypermagnetic flux
required by our mechanism and we provide a measure of the parity breaking by
connecting the degree of knottedness of the flux lines to the BAU. We rule out
the ordinary axion as a possible candidate for production (around temperatures
of the order of the GeV) of {\em magnetic} knots since the produced {\em
electromagnetic} helicity is negligible (for cosmological standard) if the
initial amplitude of the axion oscillations is of the order of the Peccei-Quinn
breaking scale.Comment: 30 pages in Revtex style, 8 figure
Quantum Field Theory of three flavor neutrino mixing and oscillations with CP violation
We study in detail the Quantum Field Theory of mixing among three generations
of Dirac fermions (neutrinos). We construct the Hilbert space for the flavor
fields and determine the generators of the mixing transformations. By use of
these generators, we recover all the known parameterizations of the
three-flavor mixing matrix and we find a number of new ones. The algebra of the
currents associated with the mixing transformations is shown to be a deformed
algebra, when CP violating phases are present. We then derive the exact
oscillation formulas, exhibiting new features with respect to the usual ones.
CP and T violation are also discussed.Comment: 15 pages, 7 figures, RevTeX, revised versio
LH prevents cisplatin-induced apoptosis in oocytes and preserves female fertility in mouse
Premature ovarian failure and female infertility are frequent side effects of anticancer therapies, owing to the extreme sensitivity of the ovarian reserve oocytes to the damaging effects of irradiation and chemotherapy on DNA. We report here a robust protective effect of luteinizing hormone (LH) on the primordial follicle pool of prepubertal ovaries against the cisplatin (Cs)-induced apoptosis. In vitro LH treatment of prepubertal ovarian fragments generated anti-apoptotic signals by a subset of ovarian somatic cells expressing LH receptor (LHR) through cAMP/PKA and Akt pathways. Such signals, reducing the oocyte level of pro-apoptotic TAp63 protein and favoring the repair of the Cs-damaged DNA in the oocytes, prevented their apoptosis. Noteworthy, in vivo administration to prepubertal female mice of a single dose of LH together with Cs inhibited the depletion of the primordial follicle reserve caused by the drug and preserved their fertility in reproductive age, preventing significant alteration in the number of pregnancy and of delivered pups. In conclusion, these findings establish a novel ovoprotective role for LH and further support the very attracting prospective to use physiological 'fertoprotective' approaches for preventing premature infertility and risks linked to precocious menopause in young patients who survived cancer after chemotherapy
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