The increasing use of nanoparticles in medicine has raised concerns over their ability to gain access to privileged sites in the body. Here, we show that cobalt-chromium nanoparticles (29.5 +/- 6.3 nm in diameter) can damage human fibroblast cells across an intact cellular barrier without having to cross the barrier. The damage is mediated by a novel mechanism involving transmission of purine nucleotides (such as ATP) and intercellular signalling within the barrier through connexin gap junctions or hemichannels and pannexin channels. The outcome, which includes DNA damage without significant cell death, is different from that observed in cells subjected to direct exposure to nanoparticles. Our results suggest the importance of indirect effects when evaluating the safety of nanoparticles. The potential damage to tissues located behind cellular barriers needs to be considered when using nanoparticles for targeting diseased states.

Ann R Coll Surg Engl 2007; 89: 298-300 298Medical handover is 'the transfer of professional responsibility and accountability for some or all aspects of care for a patient, or group of patients, to another person or professional group on a temporary or permanent basis'.1 The implementation of the New Deal and the European Working Time Directive has meant that junior doctors are increasingly working in shifts and that handover of clinical information is taking place more frequently. There is reduced continuity of care with patients often being looked after by more than one group of doctors on any given day.3 In many instances, doctors have no day-to-day contact with patients for whom they are responsible in the outof-hours period.2 There are many published examples of cases where poor communication between doctors has had serious consequences for patients; 3 for these reasons, it is now well recognised that accurate handover of clinical information is of great importance to patient safety. 1There are currently many different handover methods being used in clinical practice. 4 Often, a verbal handover is conducted, either by telephone or in person, where the recipient of the handover may or may not take notes to refer to over the course of his shift. Some groups arrange for a handover book or folder to be used so that teams can leave messages about patients of particular concern. In this case, there may be no verbal contact at all. Increasingly, more formal pre-prepared handover sheets are being used which contain information about all of the patients belonging to that particular team.5 This can be typed on a computer and printed out for the on-call doctor for his reference. However, this process inevitably takes more time and effort.Despite this variation in clinical practice, there is very little prospective experimental evidence in the literature investigating optimal methods of handover. The British Medical Association, in conjunction with the General Medical Council, NHS Modernisation agency, National Patient Safety Agency and the Junior Doctors Committee have recently published guidelines 4 for safe handover, but these are based largely on expert opinion. We designed a study to assess the differences in information retention for different handover styles. The styles examined included a purely verbal style, a verbal with note-taking style and a handover using a pre-prepared sheet.

No abstract