285 research outputs found
Effects of balloon injury on neointimal hyperplasia in steptozotocin-induced diabetes and in hyperinsulinemic nondiabetic pancreatic islet-transplanted rats.
BACKGROUND:
The mechanisms of increased neointimal hyperplasia after coronary interventions in diabetic patients are still unknown.
METHODS AND RESULTS:
Glucose and insulin effects on in vitro vascular smooth muscle cell (VSMC) proliferation and migration were assessed. The effect of balloon injury on neointimal hyperplasia was studied in streptozotocin-induced diabetic rats with or without adjunct insulin therapy. To study the effect of balloon injury in nondiabetic rats with hyperinsulinemia, pancreatic islets were transplanted under the kidney capsule in normal rats. Glucose did not increase VSMC proliferation and migration in vitro. In contrast, insulin induced a significant increase in VSMC proliferation and migration in cell cultures. Furthermore, in VSMC culture, insulin increased MAPK activation. A reduction in neointimal hyperplasia was consistently documented after vascular injury in hyperglycemic streptozotocin-induced diabetic rats. Insulin therapy significantly increased neointimal hyperplasia in these rats. This effect of hyperinsulinemia was totally abolished by transfection on the arterial wall of the N17H-ras-negative mutant gene. Finally, after experimental balloon angioplasty in hyperinsulinemic nondiabetic islet-transplanted rats, a significant increase in neointimal hyperplasia was observed.
CONCLUSIONS:
In rats with streptozotocin-induced diabetes, balloon injury was not associated with an increase in neointimal formation. Exogenous insulin administration in diabetic rats and islet transplantation in nondiabetic rats increased both blood insulin levels and neointimal hyperplasia after balloon injury. Hyperinsulinemia through activation of the ras/MAPK pathway, rather than hyperglycemia per se, seems to be of crucial importance in determining the exaggerated neointimal hyperplasia after balloon angioplasty in diabetic animals
Yield, quality, antioxidant, and sensorial properties of diced tomato as affected by genotype and industrial processing in Southern Italy
Research was carried out on processing tomato in Southern Italy in order to compare four round-prismatic type hybrids oriented to diced produce (4420, Miceno, Nemabrix, Impact as a control). The hybrid Nemabrix attained the highest marketable yield (180.9 t ha–1, due to both the highest number of fruit per plant and their mean weight (103.7 and 70 g, respectively), and it was not significantly different from the other genotypes in terms of processing efficiency both as a total and along dicing chain (67.8% and 65.6%, respectively). Lycopene attained the highest concentration in Nemabrix (155 mg kg–1), and β–carotene was most concentrated in 4420 and Miceno (2.8 mg kg–1). Significant differences arose between the genotypes with regard to the sensorial variables aspect, colour, taste, firmness, and fresh taste
Drug management of atrial fibrillation in light of guidelines and current evidence: an Italian Survey on behalf of Italian Association of Arrhythmology and Cardiac Pacing
AimAtrial fibrillation is a multifaceted disease requiring personalized treatment, in accordance with current ESC guidelines. Despite a wide range of literature, we still have various aspects dividing the opinion of the experts in rate control, rhythm control and thromboembolic prophylaxis. The aim of this survey was to provide a country-wide picture of current practice regarding atrial fibrillation pharmacological management according to a patient's characteristics.MethodsData were collected using an in-person survey that was administered to members of the Italian Association of Arrhythmology and Cardiac Pacing.ResultsWe collected data from 106 physicians, working in 72 Italian hospitals from 15 of 21 regions. Our work evidenced a high inhomogeneity in atrial fibrillation management regarding rhythm control, rate control and thromboembolic prophylaxis in both acute and chronic patients. This element was more pronounced in settings in which literature shows a lack of evidence and, consequently, the indications provided by the guidelines are weak or absent.ConclusionThis National survey evidenced a high inhomogeneity in current approaches adopted for atrial fibrillation management by a sample of Italian cardiologist experts in arrhythmia management. Further studies are needed to explore if these divergences are associated with different long-term outcomes
Safety of magnetic resonance imaging scanning in patients with cardiac resynchronization therapy–defibrillators incorporating quadripolar left ventricular leads
© 2020 The Authors Background: Magnetic resonance imaging (MRI) scanning of magnetic resonance (MR)-conditional cardiac implantable cardioverter-defibrillators (ICDs) can be performed safely following specific protocols. MRI safety with cardiac resynchronization therapy–defibrillators (CRT-Ds) incorporating quadripolar left ventricular (LV) leads is less clear. Objective: The purpose of this study was to evaluate the safety and effectiveness of ICDs and CRT-D systems with quadripolar LV leads after an MRI scan. Methods: The ENABLE MRI Study included 230 subjects implanted with a Boston Scientific ImageReady ICD (n = 39) or CRT-D (n = 191) incorporating quadripolar LV leads undergoing nondiagnostic 1.5-T MRI scans (lumbar and thoracic spine imaging) a minimum of 6 weeks postimplant. Pacing capture thresholds (PCTs), sensing amplitudes (SAs), and impedances were measured before and 1 month post-MRI using the same programmed LV pacing vectors. The ability to sense/treat ventricular fibrillation (VF) was assessed in a subset of patients. Results: A total of 159 patients completed a protocol-required MRI scan (MRI Protection Mode turned on) with no scan-related complications. All right ventricular (RV) and left LV PCT and SA effectiveness endpoints were met: RV PCT 99% (145/146 patients), LV PCT 100% (120/120), RV SA 99% (145/146), and LV SA 98% (116/118). In no instances did MRI result in a change in pacing vector or lead revision. All episodes of VF were appropriately sensed and treated. Conclusion: This first evaluation of predominantly CRT-D systems with quadripolar LV leads undergoing 1.5-T MRI confirmed that scanning was safe with no significant changes in RV/LV PCT, SA, programmed vectors, and VF treatment, thus suggesting that MRI in patients having a device with quadripolar leads can be performed without negative impact on CRT delivery
A new framework for assessing the contributions of professionals in the natural sciences
No abstract available
Yield, quality and antioxidants of peeled tomato as affected by genotype and industrial processing in southern Italy
Research was carried out on processing tomato in San Severo (Tavoliere delle Puglie, Foggia, Italy) in order to compare four long-type fruit hybrids oriented to peeled produce (Abbundo, Umex, Superpeel, Taylor), using a randomized complete block design with three replicates. The hybrid Superpeel reached the highest marketable yield due to the highest fruit number and mean weight; along the peeling chain, Umex and Taylor showed the highest processing efficiency. Titratable acidity and sodium were highest in Taylor fruits, whereas the highest fiber content was detected in Abbundo fruits. Compared to pre-processing fruits, peeled tomatoes showed increased values of total and soluble solids as well as reducing sugars, but decreased sugar ratio and colour. The highest concentrations of antioxidants in processed fruits were recorded in Umex for lycopene and in Superpeel for β-carotene. Compared to pre-processing fruits, in peeled tomatoes lycopene and β-carotene concentrations remained stable and polyphenols increased referring to fresh weight. The hybrids examined did not show univocal trends in terms of sensorial features
β1-Adrenergic Receptor and Sphingosine- 1-Phosphate Receptor 1 Reciprocal Down-Regulation Influences Cardiac Hypertrophic Response and Progression Toward Heart Failure: Protective Role of S1PR1 Cardiac Gene Therapy
YesThe Sphingosine-1-phosphate receptor 1 (S1PR1) and β1-adrenergic receptor
(β1AR) are G protein-coupled receptors (GPCRs) expressed in the heart. These two GPCRs have
opposing actions on adenylyl cyclase due to differential G protein-coupling. Importantly, both of
these receptors can be regulated by the actions of GPCR kinase-2 (GRK2), which triggers
desensitization and down-regulation processes. Although, classical signaling paradigms suggest
that simultaneous activation of β1ARs and S1PR1s in a myocyte would simply be opposing action
on cAMP production, in this report we have uncovered a direct interaction between these two
receptors with a regulatory involvement of GRK2.
In HEK293 cells overexpressing both β1AR and S1PR1, we
demonstrate that β1AR down-regulation can occur after sphingosine 1-phosphate (S1PR1 agonist)
stimulation while S1PR1 down-regulation can be triggered by isoproterenol (βAR agonist)
treatment. This cross-talk between these two distinct GPCRs appears to have physiological
significance since they interact and show reciprocal regulation in mouse hearts undergoing chronic
βAR stimulation and also in a rat model of post-ischemic heart failure (HF).
We demonstrate that restoring cardiac plasma membrane levels of S1PR1
produce beneficial effects counterbalancing deleterious β1AR overstimulation in HF
Performance of a multi-sensor implantable defibrillator algorithm for heart failure monitoring in the presence of atrial fibrillation
AIMS: The HeartLogic Index combines data from multiple implantable cardioverter defibrillators (ICDs) sensors and has been shown to accurately stratify patients at risk of heart failure (HF) events. We evaluated and compared the performance of this algorithm during sinus rhythm and during long-lasting atrial fibrillation (AF). METHODS AND RESULTS: HeartLogic was activated in 568 ICD patients from 26 centres. We found periods of ≥30 consecutive days with an atrial high-rate episode (AHRE) burden <1 h/day and periods with an AHRE burden ≥20 h/day. We then identified patients who met both criteria during the follow-up (AHRE group, n = 53), to allow pairwise comparison of periods. For control purposes, we identified patients with an AHRE burden <1 h throughout their follow-up and implemented 2:1 propensity score matching vs. the AHRE group (matched non-AHRE group, n = 106). In the AHRE group, the rate of alerts was 1.2 [95% confidence interval (CI): 1.0-1.5]/patient-year during periods with an AHRE burden <1 h/day and 2.0 (95% CI: 1.5-2.6)/patient-year during periods with an AHRE-burden ≥20 h/day (P = 0.004). The rate of HF hospitalizations was 0.34 (95% CI: 0.15-0.69)/patient-year during IN-alert periods and 0.06 (95% CI: 0.02-0.14)/patient-year during OUT-of-alert periods (P < 0.001). The IN/OUT-of-alert state incidence rate ratio of HF hospitalizations was 8.59 (95% CI: 1.67-55.31) during periods with an AHRE burden <1 h/day and 2.70 (95% CI: 1.01-28.33) during periods with an AHRE burden ≥20 h/day. In the matched non-AHRE group, the rate of HF hospitalizations was 0.29 (95% CI: 0.12-0.60)/patient-year during IN-alert periods and 0.04 (95% CI: 0.02-0.08)/patient-year during OUT-of-alert periods (P < 0.001). The incidence rate ratio was 7.11 (95% CI: 2.19-22.44). CONCLUSION: Patients received more alerts during periods of AF. The ability of the algorithm to identify increased risk of HF events was confirmed during AF, despite a lower IN/OUT-of-alert incidence rate ratio in comparison with non-AF periods and non-AF patients. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov/Identifier: NCT02275637
Defective β-Adrenergic Receptor Signaling Precedes the Development of Dilated Cardiomyopathy in Transgenic Mice with Calsequestrin Overexpression
Calsequestrin is a high capacity Ca(2+)-binding protein in the junctional sarcoplasmic reticulum that forms a quaternary complex with junctin, triadin, and the ryanodine receptor. Transgenic mice with cardiac-targeted calsequestrin overexpression show marked suppression of Ca(2+)-induced Ca(2+) release, myocyte hypertrophy, and premature death by 16 weeks of age (Jones, L. R., Suzuki, Y. J., Wang, W., Kobayashi, Y. M., Ramesh, V., Franzini-Armstrong, C., Cleemann, L., and Morad, M. (1998) J. Clin. Invest. 101, 1385-1393). To investigate whether alterations in intracellular Ca(2+) trigger changes in the beta-adrenergic receptor pathway, we studied calsequestrin overexpressing transgenic mice at 7 and 14 weeks of age. As assessed by echocardiography, calsequestrin mice at 7 weeks showed mild left ventricular enlargement, mild decreased fractional shortening with increased wall thickness. By 14 weeks, the phenotype progressed to marked left ventricular enlargement and severely depressed systolic function. Cardiac catheterization in calsequestrin mice revealed markedly impaired beta-adrenergic receptor responsiveness in both 7- and 14- week mice. Biochemical analysis in 7- and 14-week mice showed a significant decrease in total beta-adrenergic receptor density, adenylyl cyclase activity, and the percent high affinity agonist binding, which was associated with increased beta-adrenergic receptor kinase 1 levels. Taken together, these data indicate that alterations in beta-adrenergic receptor signaling precede the development of overt heart failure in this mouse model of progressive cardiomyopathy
Modern subcutaneous implantable defibrillator therapy in patients with cardiomyopathies and channelopathies. Data from a large multicentre registry
Aims: Patients with cardiomyopathies and channelopathies are usually younger and have a predominantly arrhythmia-related prognosis; they have nearly normal life expectancy thanks to the protection against sudden cardiac death provided by the implantable cardioverter defibrillator (ICD). The subcutaneous ICD (S-ICD) is an effective alternative to the transvenous ICD and has evolved over the years. This study aimed to evaluate the rate of inappropriate shocks (IS), appropriate therapies, and device-related complications in patients with cardiomyopathies and channelopathies who underwent modern S-ICD implantation. Methods and results: We enrolled consecutive patients with cardiomyopathies and channelopathies who had undergone implantation of a modern S-ICD from January 2016 to December 2020 and who were followed up until December 2022. A total of 1338 S-ICD implantations were performed within the observation period. Of these patients, 628 had cardiomyopathies or channelopathies. The rate of IS at 12 months was 4.6% [95% confidence interval (CI): 2.8-6.9] in patients with cardiomyopathies and 1.1% (95% CI: 0.1-3.8) in patients with channelopathies (P = 0.032). No significant differences were noted over a median follow-up of 43 months [hazard ratio (HR): 0.76; 95% CI: 0.45-1.31; P = 0.351]. The rate of appropriate shocks at 12 months was 2.3% (95% CI: 1.1-4.1) in patients with cardiomyopathies and 2.1% (95% CI: 0.6-5.3) in patients with channelopathies (P = 1.0). The rate of device-related complications was 0.9% (95% CI: 0.3-2.3) and 3.2% (95% CI: 1.2-6.8), respectively (P = 0.074). No significant differences were noted over the entire follow-up. The need for pacing was low, occurring in 0.8% of patients. Conclusion: Modern S-ICDs may be a valuable alternative to transvenous ICDs in patients with cardiomyopathies and channelopathies. Our findings suggest that modern S-ICD therapy carries a low rate of IS. Clinical Trial Registration: URL: http://clinicaltrials.gov/Identifier: NCT02275637
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