Breum Alford (trampsink71)

Coronary sinus-related arrhythmias are common; however, it is difficult to perform radiofrequency (RF) ablation at these sites efficiently and safely. High-power, short-duration ablation (HPSD) is a proven alternative strategy for pulmonary vein isolation (PVI); whether it can be applied to ablation of the coronary sinus is unknown. The purpose of this preliminary study was to evaluate the feasibility and safety of HPSD ablation in the coronary sinus. Firstly, we demonstrated 4 clinical cases of 3 types of arrhythmias who had unsuccessful ablation with standard power initially, but received successful ablations with HPSD. Secondly, RF ablation was performed in the coronary sinus ostium (CSO) and middle cardiac vein (MCV) of 4 in vitro swine hearts. Two protocols were compared HPSD (45 W/5 S×5 rounds) and a conventional strategy that used low-power, long-duration ablation (LPLD 25 W/10 S ×5 rounds). The total duration of HPSD protocol was 25 s, and which of LPLD was 50 s. A total of 28 lesions were created. HPSD can produce longer, wider, deeper, and larger lesions than LPLD. This difference was more pronounced when the ablation was in the MCV. One instance of steam pop occurred during LPLD in the MCV. HPSD is an effective alternative strategy for ablation in coronary sinus according to clinical applications and preliminary animal study. However, the safety needs to be further evaluated based on more animal and clinical studies. HPSD is an effective alternative strategy for ablation in coronary sinus according to clinical applications and preliminary animal study. However, the safety needs to be further evaluated based on more animal and clinical studies.Lipases are versatile biocatalysts with many biotechnological applications and the necessity of screening, production and characterization of new lipases from diverse microbial strains to meet industrial needs is constantly emerging. In this study, the lipase gene (gklip) from a thermophilic bacterium, Geobacillus kaustophilus DSM 7263 T was cloned into the pET28a ( +) vector with N-terminal 6xHis-tag. The recombinant gklip gene was heterologously expressed in host E. coli BL21 (DE3) cells and purified by Ni-NTA affinity chromatography. Histidine tag was removed from the purified 6xHistag-Gklip enzyme with thrombin enzyme and the molecular mass was determined to be approximately 43 kDa by SDS-PAGE. Gklip showed optimal activity at pH 8.0 and 50 °C. The specific hydrolytic activities against substrates were significantly increased by the removal of the His-tag. Km and kcat values of Gklip against p-nitrophenyl palmitate (pNPP, 4-nitrophenyl palmitate) as the target substrate were found to be as 1.22 mM and 417.1 min-1, respectively. Removing His-tag changed the substrate preference of the enzyme leading to maximum lipolytic activity towards C10 and C12 lipids. Similarly, the activity against coconut oil that containing 62% medium-chain fatty acids was significantly higher than other oils. Furthermore, preservation of activity in the presence of inhibitors, organic solvents support the effect of lid structure of the enzyme.In this study, a fluorescence detection strategy is reported for the peptidase activity assay, which is based on fluorescence resonance energy transfer (FRET) from a fluorophore-labelled peptide to graphene oxide (GO). By the hydrolysis of the peptide, the fluorophore-labelled peptide releases the fluorophore 5-carboxyfluorescein, which can avoid quenching from GO. Thus, the increased intensity of the obtained fluorescence signal in the assay is directly dependent on the peptidase activity. As a model case of the developed strategy, the activity determination of pancreatic elastase (PE) is performed. Under the optimal experimental conditions at an excitation wavelength of 494 nm, the activity of PE can be determined in the range from 0.003 to 0.10 U/mL, with a detection limit of 0.001 U/mL at the emission wavelength of