Shedding of clinical-grade lentiviral vectors is not detected in a gene therapy setting.

Gene therapy using viral vectors that stably integrate into ex vivo cultured cells holds great promises for the treatment of monogenic diseases as well as cancer. However, carry-over of infectious vector particles has been described to occur upon ex vivo transduction of target cells. This, in turn, may lead to inadvertent spreading of viral particles to off-target cells in vivo, raising concerns for potential adverse effects, such as toxicity of ectopic transgene expression, immunogenicity from in vivo transduced antigen-presenting cells and, possibly, gene transfer to germline cells. Here, we have investigated factors influencing the extent of lentiviral vector (LV) shedding upon ex vivo transduction of human hematopoietic stem and progenitor cells. Our results indicate that, although vector carry-over is detectable when using laboratory-grade vector stocks, the use of clinical-grade vector stocks strongly decreases the extent of inadvertent transduction of secondary targets, likely because of the higher degree of purification. These data provide supportive evidence for the safe use of the LV platform in clinical settings.

The "Chimney approach" for transcatheter aortic valve implantation: A strategy for trans axillarian bareback approach in patients with no other access options.

AIM: to describe the procedural steps and to report the short term follow up of our initial experience with an axillarian bareback Dacron graft based technique that could potentially reduce the rate of vascular and ischemic complications during transcatheter aortic valve implantation in patients with contraindications to trans-femoral approach and with patent left internal mammary arterial graft to left anterior descending coronary artery (LIMA-LAD) or small caliber axillarian/subclavian arteries. METHODS AND RESULTS: Four patients were treated with TAVI implantation with a trans axillarian bareback approach. Three out of four had a patent LIMA-LAD graft. In three patients, femoral approach was not considered as an option for the presence of diffuse peripheral vascular disease, while in one for the small caliber of iliac-femoral arteries. All procedures were performed under general anaesthesia. No procedural complications occurred. CONCLUSIONS: In this initial experience, the axillarian bareback approach technique allowed a safe and successful TAVI implant in a subgroup of patients with a high risk of procedural complications due to the presence of a patent LIMA-LAD or vessels of small caliber. Considering the increasing number of patients referred for TAVI, in the next future the axillarian bareback approach could represent a safer alternative to direct cannulation in patients with severe aortic stenosis with no other access options.

Respiratory and leg muscles perceived exertion during exercise at altitude.

We compared the rate of perceived exertion for respiratory (RPE,resp) and leg (RPE,legs) muscles, using a 10-point Borg scale, to their specific power outputs in 10 healthy male subjects during incremental cycle exercise at sea level (SL) and high altitude (HA, 4559 m). Respiratory power output was calculated from breath-by-breath esophageal pressure and chest wall volume changes. At HA ventilation was increased at any leg power output by ∼ 54%. However, for any given ventilation, breathing pattern was unchanged in terms of tidal volume, respiratory rate and operational volumes of the different chest wall compartments. RPE,resp scaled uniquely with total respiratory power output, irrespectively of SL or HA, while RPE,legs for any leg power output was exacerbated at HA. With increasing respective power outputs, the rate of change of RPE,resp exponentially decreased, while that of RPE,legs increased. We conclude that RPE,resp uniquely relates to respiratory power output, while RPE,legs varies depending on muscle metabolic conditions.