Efficacy of multi-electrode duty-cycled radiofrequency ablation in patients with paroxysmal and persistent atrial fibrillation

Background: Radiofrequency (RF) catheter ablation is a first-line therapy for patients with drug-refractory atrial fibrillation (AF). Complete isolation of electrical potentials at the ostium of pulmonary vein (PV) is a challenging procedure. There are different techniques and devicesused for PV isolation (PVI). The objective of this study was to evaluate the efficacy and safety of PV ablation catheter (PVAC).Methods: A total of 67 consecutive patients with paroxysmal and persistent AF were treated with the PVAC. The patients’ information were obtained from clinical charts. Follow-up was obtained by one day Holter monitoring at 2, 4, 6, 8, 10 and 12 months after ablation and ECG registration if any symptoms or arrhythmia occurred.Results: The median follow-up duration was 16 months (IQR: 12–20 months). In the population which was available at follow-up (n = 60), 22 (36.7%) patients were in sustained sinus rhythm (SR) without anti-arrhythmic drugs (AAD). Overall 26 (43.3%) patients were in sustained SR with and without AAD. In the paroxysmal AF group, after a single PVAC ablation procedure (n = 39), 19 (48.7%) patients had sustained SR without AAD. In the persistent AF group (n = 15), after the single PVAC ablation, 2 (13.3%) patients had sustained SR without AAD.Conclusions: PVI with PVAC is a safe procedure with 48.7% efficacy in patients with paroxysmal AF. The efficacy of PVAC in patients with persistent or long-standing persistent AF is not acceptable

Role of miRNA in Melanoma Development and Progression

Melanoma is one of the most aggressive and progressive skin cancers. It develops from normal pigment-producing cells known as melanocytes, so it is important to know the mechanism behind such transformations. The study of metastasis mechanisms is crucial for a better understanding the biology of neoplastic cells. Metastasis of melanoma, or any type of cancer, is a multi-stage process in which the neoplastic cells leave the primary tumour, travel through the blood and/or lymphatic vessels, settle in distant organs and create secondary tumours. MicroRNA (miRNA) can participate in several steps of the metastatic process. This review presents the role of miRNA molecules in the development and progression as well as the immune response to melanoma

The Characterization of Scaffolds Based on Dialdehyde Chitosan/Hyaluronic Acid

In this work, two-component dialdehyde chitosan/hyaluronic acid scaffolds were developed and characterized. Dialdehyde chitosan was obtained by one-step synthesis with chitosan and sodium periodate. Three-dimensional scaffolds were prepared by the lyophilization method. Fourier transform infrared spectroscopy (FTIR) was used to observe the chemical structure of scaffolds and scanning electron microscopy (SEM) imaging was done to assess the microstructure of resultant materials. Thermal analysis, mechanical properties measurements, density, porosity and water content measurements were used to characterize physicochemical properties of dialdehyde chitosan/hyaluronic acid 3D materials. Additionally, human epidermal keratinocytes (NHEK), dermal fibroblasts (NHDF) and human melanoma cells (A375 and G-361) were used to evaluate cell viability in the presence of subjected scaffolds. It was found that scaffolds were characterized by a porous structure with interconnected pores. The scaffold composition has an influence on physicochemical properties, such as mechanical strength, thermal resistance, porosity and water content. There were no significant differences between cell viability proliferation of all scaffolds, and this observation was visible for all subjected cell lines