87 research outputs found
starMC: an automata based CTL* model checker
Model-checking of temporal logic formulae is a widely used technique for the verification of systems. CTL [Image: see text] is a temporal logic that allows to consider an intermix of both branching behaviours (like in CTL) and linear behaviours (LTL), overcoming the limitations of LTL (that cannot express “possibility”) and CTL (cannot fully express fairness). Nevertheless CTL [Image: see text] model-checkers are uncommon. This paper presents (1) the algorithms for a fully symbolic automata-based approach for CTL [Image: see text] , and (2) their implementation in the open-source tool starMC, a CTL [Image: see text] model checker for systems specified as Petri nets. Testing has been conducted on thousands of formulas over almost a hundred models. The experiments show that the fully symbolic automata-based approach of starMC can compute the set of states that satisfy a CTL [Image: see text] formula for very large models (non trivial formulas for state spaces larger than 10(480) states are evaluated in less than a minute)
Parenteral amino acids v. dextrose infusion: an anabolic strategy to minimise the catabolic response to surgery while maintaining normoglycaemia in diabetes mellitus type 2 patients
Loss of body protein and hyperglycaemia represent typical features of the stress response to surgery and anaesthesia. This appears to be particularly pronounced in patients with diabetes mellitus type 2. The aim of the present study was to highlight the greater benefit of amino acids (AA) as represented by positive protein balance and maintenance of blood glucose homoeostasis compared with dextrose (DEX) in diabetic patients after colorectal surgery. A total of thirteen patients underwent a 5h stable isotope infusion study (2h fasted, 3h fed with an infusion of AA (n 6) or DEX (n 7)) on the second post-operative day. Glucose and protein kinetics were assessed by using the stable isotopes l-[1-13C]leucine and [6,6-2H2]glucose. The transition from fasted to fed state decreased endogenous glucose production (P<0·001) in both groups, with a more profound effect in the DEX group (P=0·031). In contrast, total glucose production was increased by the provision of DEX while being lowered by AA (P=0·021). Feeding decreased protein oxidation (P=0·009) and protein synthesis in the AA group, whereas DEX infusion did not affect oxidation and even decreased protein synthesis. Therefore, only AA shifted protein balance to a positive value, while patients in the DEX group remained in a catabolic state (P<0·001). Parenteral nutritional support with AA rather than with DEX is an effective strategy to achieve a positive protein balance while maintaining normoglycaemia in diabetic patients after colorectal surger
Case report: Self-expanding transcatheter valve implantation (Acurate Neo 2) in a very small native aortic annulus
Transcatheter aortic valve replacement (TAVR) is a treatment of choice in patients with symptomatic severe aortic valve stenosis (AS) and intermediate-to-high surgical risk. The presence of a small aortic annulus (SAA) has been associated with a higher incidence of prosthesis–patient mismatch (PPM) when surgical aortic valve replacement (sAVR) is performed. TAVR might be a treatment option offering better hemodynamics with a lower incidence of PPM. When a severe AS with a SAA is treated, TAVR-related risk as the coronary obstruction and the annulus rupture, must be also prevented. We present a case of a TAVR in a very small aortic annulus; to our knowledge, this is the smallest native aortic annulus treated percutaneously in a tricuspid stenotic aortic valve with a Self-Expanding Transcatheter Heart Valve (THV) Acurate Neo 2
Cardiopulmonary-bypass induces hyperglycemia only in preoperative insulin resistant patients
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Heart failure: Pilot transcriptomic analysis of cardiac tissue by RNA-sequencing
Background: Despite left ventricular (LV) dysfunction contributing to mortality in chronic heart failure (HF), the molecular mechanisms of LV failure continues to remain poorly understood and myocardial biomarkers have yet to be identified. The aim of this pilot study was to investigate specific transcriptome changes occurring in cardiac tissues of patients with HF compared to healthy condition patients to improve diagnosis and possible treatment of affected subjects.
Methods: Unlike other studies, only dilated cardiomyopathy (DCM) (n = 2) and restrictive cardiomyopathy (RCM) (n = 2) patients who did not report family history of the disease were selected with the aim of obtaining a homogeneous population for the study. The transcriptome of all patients were studied by RNA-sequencing (RNA-Seq) and the read counts were adequately filtered and normalized using a recently developed user-friendly tool for RNA-Seq data analysis, based on a new graphical user interface (RNA-SeqGUI).
Results: By using this approach in a pairwise comparison with healthy donors, we were able to identify DCM- and RCM-specific expression signatures for protein-coding genes as well as for long noncoding RNAs (lncRNAs). Differential expression of 5 genes encoding different members of the mediator complex was disclosed in this analysis. Interestingly, a significant alteration was found for genes which had never been associated with HF until now, and 27 lncRNA/mRNA pairs that were significantly altered in HF patients.
Conclusions: The present findings revealed specific expression pattern of both protein-coding and lncRNAs in HF patients, confirming that new LV myocardial biomarkers could be reliably identified using Next-Generation Sequencing-based approaches
Current Use of Oral Anticoagulation Therapy in Elderly Patients with Atrial Fibrillation: Results from an Italian Multicenter Prospective Study-The ISNEP Study
Background: Atrial fibrillation (AF) is the most common heart arrhythmia, and its prevalence increases with age. Oral Anticoagulant Therapy (OAT) with non-vitamin K antagonist oral anticoagulants (NOACs) or vitamin K antagonists (VKAs) is essential to avoid thromboembolic events in AF. However, this treatment is associated with a high risk of bleeding and low adherence in elderly patients. Aim: The aim was to evaluate the real-world use of OAT in a population of patients aged >= 80 years in twenty-three Italian centers and to investigate the tolerance of and patient satisfaction with this therapy. Methods: The ISNEP Study is a multicenter cross-sectional study enrolling patients with AF and aged >= 80 years and treated with either NOACs or VKAs. A written questionnaire was administered to each patient to evaluate the adherence to and patient satisfaction with this therapy. Results: The study included 641 patients with a mean age of 85 (82-87) years. The use of NOACs was reported in 93.0% of cases, with the remaining 7.0% treated with VKAs. A history of stroke events was reported in five (11.1%) and one (0.2%) patients in the VKA and NOAC groups, respectively. The rate of referred ecchymosis/epistaxis was significantly higher in the VKA group compared to the NOAC group (p < 0.001). Patients receiving NOACs reported a substantial improvement in their quality of life compared to the VKA group. Conclusions: A small, but not negligible, proportion of elderly AF patients is still treated with VKAs. Patients treated with NOAC have a higher level of satisfaction with the therapy and complete adherence
Renal function impairment predicts mortality in patients with chronic heart failure treated with resynchronization therapy
Background: The use of cardiac resynchronization therapy (CRT) and implantable cardioverter- defibrillator (ICD) for advanced heart failure (HF) is increasing. Renal dysfunction is a common condition in HF which is associated with a worse survival. The study aims at identifying in patients with advanced HF treated with CRT the effect of baseline glomerular filtration rate (GFR), GFR improvement and left ventricular ejection fraction (LVEF) change, after 6-months of CRT implant, on survival.
Methods: The study population consisted of 375 advanced HF patients who received a CRT between 1999 and 2009, of these 277 received also an ICD implant. Clinical characteristics (New York Heart Association [NYHA] functional class, ischemic vs. non-ischemic etiology, atrial fibrillation, diabetes, hypertension, LVEF, QRS duration and GFR were recorded. The use of common used drugs was evaluated. Cox proportional hazards analysis was calculated in order to evaluate variables associated to mortality.
Results: During a median follow-up of 43.0 months, 93 (24.8%) patients died. Patients deceased during the study had at baseline higher NYHA class and lower LVEF and GFR. In Cox regression analysis, GFR predicts long-term mortality (hazard ratio [HR] 0.983; 95% confidence interval [CI] 0.969–0.998; p = 0.023) independently from the effect of others covariates. In addition, a positive GFR improvement 6 months after CRT implant is significantly associated with a lower hazard of mortality (for each 10 mL/min of GFR improvement HR 0.86; 95% CI 0.75–0.99; p = 0.038).
Conclusions: GFR is a significant predictor of mortality in advanced HF patients who received CRT. A GFR improvement 6 months after CRT implant is significantly associated with a lower hazard of mortality.
The effect of risedronate on osteogenic lineage is mediated by cyclooxygenase-2 gene upregulation
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