Advanced ventricular arrhythmias during bedside pulmonary artery catheterization

To determine the incidence of advanced arrhythmias and acute right bundle branch block during beside pulmonary artery catheterization, 119 critically ill patients undergoing 150 pulmonary artery catheterizations were prospectively studied using continuous electrocardiographic monitoring with permanent recordings. Ventricular arrhythmias other than isolated premature ventricular contractions, couplets or bigeminy occurred during 80 of the 150 catheterizations (53 percent). These included ventricular salvos (three to five consecutive premature ventricular contractions) in 30 percent, non-sustained ventricular tachycardia (five to 30 premature ventricular contractions) in 20 percent and sustained ventricular tachycardia (more than 30 consective premature ventricular contractions) in 3 percent. In two patients, ventricular fibrillation developed; in another three patients, lidocaine or a precordial thump was required to terminate the episodes of ventricular tachycardia. The incidence of advanced ventricular arrhythmias was statistically correlated with either the presence of predisposing risk factors for ventricular ectopy (p < 0.05) or prolonged catheterization time (p < 0.01). A new right bundle branch block developed in seven patients (5 percent) and persisted for a mean of 9.5 hours

An investigation into the interactions of gold nanoparticles and anti-arthritic drugs with macrophages, and their reactivity towards thioredoxin reductase

Gold(I) complexes are an important tool in the arsenal of established approaches for treating rheumatoid arthritis (RA), while some recent studies have suggested that gold nanoparticles (Au NPs) may also be therapeutically efficacious. These observations prompted the current biological studies involving gold(I) anti-RA agents and Au NPs, which are aimed towards improving our knowledge of how they work. The cytotoxicity of auranofin, aurothiomalate, aurothiosulfate and Au NPs towards RAW264.7 macrophages was evaluated using the MTT assay, with the former compound proving to be the most toxic. The extent of cellular uptake of the various gold agents was determined using graphite furnace atomic absorption spectrometry, while their distribution within macrophages was examined using microprobe synchrotron radiation X-ray fluorescence spectroscopy. The latter technique showed accumulation of gold in discrete regions of the cell, and co-localisation with sulfur in the case of cells treated with aurothiomalate or auranofin. Electrospray ionization mass spectrometry was used to characterize thioredoxin reductase (TrxR) in which the penultimate selenocysteine residue was replaced by cysteine. Mass spectra of solutions of TrxR and aurothiomalate, aurothiosulfate or auranofin showed complexes containing bare gold atoms bound to the protein, or protein adducts containing gold atoms retaining some of their initial ligands. These results support TrxR being an important target of gold(I) drugs used to treat RA, while the finding that Au NPs are incorporated into macrophages, but elicit little toxicity, indicates further exploration of their potential for treatment of RA is warranted