Purification and properties of a laccase from the mushroom Agaricus sinodeliciosus.

A homogeneous monomeric laccase (ASL) from Agaricus sinodeliciosus, with a molecular mass of 65 kDa, was isolated using ion-exchange chromatography (CM-cellulose and Q-Sepharose) and gel-filtration chromatography (Superdex 75). This laccase exhibited maximum activity at 50 °C and pH 5.0. Hg2+ and Cd2+ significantly inhibited its activity. The laccase displayed a Km value of 0.9 mM toward 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS). In addition to ABTS, ASL exhibited higher affinity toward o-toluidine and benzidine than other substrates. ASL is able to decolorize malachite green and Eriochrome black T.

Cardiac-specific overexpression of CREM-IbΔC-X via CRISPR/Cas9 in mice presents a new model of atrial cardiomyopathy with spontaneous atrial fibrillation.

Atrial cardiomyopathy (ACM) forms the substrate for atrial fibrillation (AF) and underlies the potential for atrial thrombus formation and subsequent stroke. However, generating stable animal models that accurately replicate the entire progression of atrial lesions, particularly the onset of AF, presents significant challenges. In the present study, we found that the isoform of CRE-binding protein modulator (CREM-IbΔC-X), which is involved in the regulation of cardiac development and atrial rhythm, was highly expressed in atrial biopsies from patients with AF. Building upon this finding, we employed CRISPR/Cas9 technology to create a mouse model with cardiac-specific overexpression of CREM-IbΔC-X (referred to as CS-CREM mice). This animal model effectively illustrated the development of ACM through electrophysiological and structural remodelings over time. Proteomics and Chip-qPCR analysis of atrial samples revealed significant upregulation of cell-matrix adhesion and extracellular matrix structural components, alongside significant downregulation of genes related to atrial functions in the CS-CREM mice. Furthermore, the corresponding responses to anti-arrhythmia drugs, i.e., amiodarone and propafenone, suggested that CS-CREM mice could serve as an ideal in vivo model for drug testing. Our study introduced a novel ACM model with spontaneous AF by cardiac-specifically overexpressing CREM-IbΔC-X in mice, providing valuable insights into the mechanisms and therapeutic targets of ACM.

Practical Electrochemical Method to Enhance Needle Visibility during Ultrasound Imaging.

Ultrasound-guided needle interventions play a pivotal role in the diagnosis and treatment processes in clinical practice. However, existing echogenic needles face challenges in achieving a balance between effectiveness, ease of manufacturing, and inexpensiveness. In this study, we developed an echogenic needle that encompassed the aforementioned advantages through the use of the electrolysis technology. The overall contour of the needle after electrolysis was observed using bright-field microscopy, while scanning electron microscopy (SEM) was employed to examine the micro-variations on the needle's surface. Subsequently, we validated the enhanced visualization effects in vitro (pork) and in vivo (anesthetized rabbit's thigh) puncture phantoms. To ensure the safety of the needles after the puncture procedure, we conducted Vickers hardness tests, SEM detection, bright-field microscopy, and DAPI staining. The results demonstrated that the surface roughness of the needle increased with the duration of electrolysis. Taking into account the comprehensive safety tests, the needle, subjected to 40 s of electrolysis, demonstrated a safe and effective enhancement of ultrasound visualization.