643 research outputs found

    Sensitive and quantitative method to evaluate DNA methylation of the positive regulatory domains (PRDI, PRDII) and cAMP response element (CRE) in human endothelial nitric oxide synthase promote

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    Nitric oxide plays a prominent role in the cardiovascular system and much attention has been devoted in the last years on deciphering the regulation of human endothelial nitric oxide synthase (eNOS) expression. Epigenetic-based mechanisms have a key role in the eNOS expression and their pathologic perturbations may have profound effects on the steady state RNA levels in the endothelium. The human eNOS promoter lacks a canonical TATA box and it does not contain a proximal CpG island. A differentially DNA methylated region (DMR) in the native eNOS proximal promoter is involved in gene expression regulation. Here we describe a quantitative, sensitive and cost-effective method that, relying on a novel normalization strategy, allows the quantification of DNA methylation status of the positive regulatory domains (PRDI, PRDII) and cAMP response element (CRE) in human eNOS promoter. This technique will enable to explore the functional relevance of DNA methylation perturbations of eNOS promoter both under pathological and physiological conditions

    The atherosclerosis of the sinus node artery is associated with an increased history of supra-ventricular arrhythmias : a retrospective study on 541 standard coronary angiograms

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    Background. The ischemic damage of the sinus node (SN) is a well known cause of cardiac arrhythmias and can be a consequence of any flow abnormality in the sinus node artery (SNA). Accordingly we aimed this retrospective study to: (1) evaluate the suitability of the standard coronary angiography to study the SNA and (2) determine if the percentage of subjects with a positive retrospective history of supra-ventricular arrhythmias (SVA) differs in patients with normal and diseased SNA ascertained at the time of coronary angiography. Methods and Results. Out of the 541 coronary angiograms reviewed the SNA was visible for its entire course in 486 cases (89.8%). It was found to arise from the right side of the coronary circulation in 266 cases (54.7%) slightly more often than from the left, 219 cases (45.1%). One patient had 2 distinct SNA arising from either side of the coronary circulation. For the second objective, we studied the 333 patients with: (a) coronary artery disease (CAD), (b) properly evaluable SNA and (c) complete clinical history available. In 51 (15.3%) a SNA disease was found, 41.2% of them had a positive SVA history, mainly atrial fibrillation (AF), whereas only 7.4% of patients with a positive history of SVA could be found in the non-SNA diseased. This difference was statistically significant (P < 0.001). Conclusions. (1) The evaluation of the SNA is feasible in clinical practice during a standard coronary angiography; (2) this may be relevant since angiographically detectable SNA disease was significantly associated with a positive history of SVA

    Awareness, treatment, and control of major cardiovascular risk factors in a small-scale Italian community : results of a screening campaign

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    Introduction: Hypertension, hypercholesterolemia, and diabetes are the main causes of cardiovascular diseases in developed countries. However, these conditions are still poorly recognized and treated. Objective: This study aimed at estimating the prevalence, awareness, treatment, and control rates of major cardiovascular risk factors in an unselected sample of individuals of a small community located in northern Italy. Methods: We screened 344 sequential subjects in this study. Data collection included family and clinical history, anthropometric data, blood pressure, blood glucose, and serum cholesterol values. Individual cardiovascular risk profiles were assessed by risk charts of the Progetto Cuore. Results: Based on personal history and/or measured values, 78.2% of subjects had hypercholesterolemia (total cholesterol levels > 190 mg/dL), 61.0% had central obesity (waist circumference 65 94 cm for men and 6580 cm for women), 51.2% had arterial hypertension (blood pressure 65 140/90 mmHg), 8.1% had diabetes (blood glucose 65 126 mg/dL), 22.7% had impaired fasting glucose (blood glucose 100\u2013125 mg/dL), and 35.5% were overweight (body mass index 25\u201329 kg/m2). Alcohol drinkers and smokers accounted for 46.2% and 22.4% of subjects, respectively. Awareness of hypertension, hypercholesterolemia, and diabetes was poor, and control of these risk factors, except for diabetes, was even worse. Prevalence of high blood pressure, high serum cholesterol, overweight, and obesity significantly increased with aging. Hypercholesterolemia and obesity were significantly more common in women, while overweight and diabetes in men. In 15.4% of participants, the risk of a major cardiovascular event in the next 10 years was either high or very high. Conclusion: In a small community in a wealthy region of Italy, the prevalence of major cardiovascular risk factors is high, while awareness, treatment, and control are poor. Such a result highlights the importance of screening campaigns as a strategy to improve early diagnosis and access to treatment, and thus effective prevention of cardiovascular diseases in the general population

    Development of a Nanodroplet Formulation for Triggered Release of BIO for Bone Fracture Healing

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    Impaired fracture healing impacts patients’ quality of life and imposes a financial burden on healthcare services. Up to 10% of bone fractures result in delayed/non-union fractures, for which new treatments are urgently required. However, systemic delivery of bone anabolic molecules is often sub-optimal and can lead to significant side effects. In this study, we developed ultrasound (US) responsive nano-sized vehicles in the form of perfluorocarbon nanodroplets (NDs), as a means of targeting delivery of drugs to localised tissues. We tested the hypothesis that NDs could stably encapsulate BIO (GSK-3β inhibitor), which could then be released upon US stimulation to activate Wnt signalling and induce ossification. NDs (~280 nm) were prepared from phospholipids and liquid perfluorocarbon and their stability and drug loading was studied by NTA (Nano Tracking Analysis) and HPLC. ND cytotoxicity was assessed in patient-derived bone marrow stromal cells (BMSCs) with Alamar Blue (24 h), and in vitro bioactivity of BIO-NDs was evaluated in a 3T3 Wnt-pathway reporter cell line with luciferase readout. To investigate the acoustic behaviour of NDs, 2% agarose (LM) containing NDs was injected into a bespoke bone fracture model (Sawbones) of various geometries and stimulated by US (1 MHz, 5% duty cycle, 1 MPa, 30 s), allowing the simultaneous capture of optical images and acoustic emissions. Femoral bone hole defects (1–2 mm) were made in WT-MF1 mice (age: 8–12 wks) and DiR-labelled NDs (100 µL, 109 NDs/mL, i.v.) were injected post-fracture to determine biodistribution by IVIS imaging. NDs were stable (4 and 37 °C) and retained >90% BIO until US was applied, which caused ~100% release. ND exposure up to a concentration of 109 NDs/mL showed no cytotoxicity (24 h). BIO-loaded NDs induced Wnt pathway activation in a dose dependent manner. Biodistribution of DiR-NDs in a femoral bone hole defect model in mice demonstrated increased localisation at the fracture site (~2-fold relative to that found in healthy mice or contralateral femurs at 48 h)

    Fluid mechanical modeling of the upper urinary tract

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    The upper urinary tract (UUT) consists of kidneys and ureters, and is an integral part of the human urogenital system. Yet malfunctioning and complications of the UUT can happen at all stages of life, attributed to reasons such as congenital anomalies, urinary tract infections, urolithiasis and urothelial cancers, all of which require urological interventions and significantly compromise patients' quality of life. Therefore, many models have been developed to address the relevant scientific and clinical challenges of the UUT. Of all approaches, fluid mechanical modeling serves a pivotal role and various methods have been employed to develop physiologically meaningful models. In this article, we provide an overview on the historical evolution of fluid mechanical models of UUT that utilize theoretical, computational, and experimental approaches. Descriptions of the physiological functionality of each component are also given and the mechanical characterizations associated with the UUT are provided. As such, it is our aim to offer a brief summary of the current knowledge of the subject, and provide a comprehensive introduction for engineers, scientists, and clinicians who are interested in the field of fluid mechanical modeling of UUT

    Stress corrosion cracking of additively manufactured alloy 625

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    Laser bed powder fusion (LPBF) is an additive manufacturing technology for the fabrication of semi-finished components directly from computer-aided design modelling, through melting and consolidation, layer upon layer, of a metallic powder, with a laser source. This manufacturing technique is particularly indicated for poor machinable alloys, such as Alloy 625. However, the unique microstructure generated could modify the resistance of the alloy to environment assisted cracking. The aim of this work was to analyze the stress corrosion cracking (SCC) and hydrogen embrittlement resistance behavior of Alloy 625 obtained by LPBF, both in as-built condition and after a standard heat treatment (grade 1). U-bend testing performed in boiling magnesium chloride at 155 and 170â—¦C confirmed the immunity of the alloy to SCC. However, slow strain rate tests in simulated ocean water on cathodically polarized specimens highlighted the possibility of the occurrence of hydrogen embrittlement in a specific range of strain rate and cathodic polarization. The very fine grain size and dislocation density of the thermally untreated specimens appeared to increase the hydrogen diffusion and embrittlement effect on pre-charged specimens that were deformed at the high strain rate. Conversely, heat treatment appeared to mitigate hydrogen embrittlement at high strain rates, however at the slow strain rate all the specimens showed a similar behavior

    Catheter ablation in an 80-year-old male with late-onset Wolff-Parkinson-White syndrome

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    Wolff-Parkinson-White syndrome is a congenital condition involving abnormal conductive cardiac tissue between atria and ventricles, that provides a pathway for a re-entrant tachycardia circuit or rapid repetitive ventricular response during atrial fibrillation. Clinical onset is usually from childhood to middle age, and symptoms vary in severity from palpitations (with or without syncope) to cardiac arrest. Presentation varies depending on the patient\u2019s age and presence of comorbidities, as arrhythmias are less tolerated in case of an associated heart disease. In individuals who do not experience symptoms, the condition may go unnoticed for years. We describe the case of an 80-year-old Caucasian male with late-onset of Wolff-Parkinson-White syndrome. He presented with a regular, hemodynamically unstable wide-complex tachycardia with left bundle branch morphology, successfully treated with medical therapy. After recurrence of tachycardia, he underwent an electrophysiological study that showed an orthodromic atrioventricular re-entrant tachycardia using a posterolateral accessory pathway and with functional left bundle branch block. Transseptal radiofrequency catheter ablation of the accessory pathway was successfully performed. After 15 months of follow-up, there was no tachycardia recurrence or findings of pre-excitation on the electrocardiogram. The treatment of both supraventricular and ventricular arrhythmias may be challenging especially in elderly patients. Catheter ablation of left accessory pathways with transseptal approach is feasible and effective in old patients with late-onset Wolff-Parkinson-White syndrome
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