Gastrointestinal Absorption and Toxicity of Nanoparticles and Microparticles: Myth, Reality and Pitfalls explored through Titanium Dioxide.

Daily oral exposure to vast numbers (>1013/adult/day) of micron or nano-sized persistent particles has become the norm for many populations. Significant airborne particle exposure is deleterious, so what about ingestion? Titanium dioxide in food grade form (fgTiO2) , which is an additive to some foods, capsules, tablets and toothpaste, may provide clues. Certainly, exposed human populations accumulate these particles in specialised intestinal cells at the base of large lymphoid follicles (Peyer's patches) and it's likely that a degree of absorption goes beyond this- i.e. lymphatics to blood circulation to tissues. We critically review the evidence and pathways. Regarding potential adverse effects, our primary message, for today's state-of-art, is that in vivo models have not been good enough and at times woeful. We provide a 'caveats list' to improve approaches and experimentation and illustrate why studies on biomarkers of particle uptake, and lower gut/mesenteric lymph nodes as targets, should be prioritized.

Robust rapid-setting antibacterial liquid bandages.

Bandaging is a steadfast but time-consuming component of wound care with limited technical advancements to date. Bandages must be changed and infection risk managed. Rapid-set liquid bandages are efficient alternatives but lack durability or inherent infection control. We show here that antibacterial zinc (Zn) and copper (Cu) species greatly enhance the barrier properties of the natural, waterproof, bio-adhesive polymer, shellac. The material demonstrated marked antibacterial contact properties and, in ex-vivo studies, effectively locked-in pre-applied therapeutics. When challenged in vivo with the polybacterial bovine wound infection 'digital dermatitis', Zn/Cu-shellac adhered rapidly and robustly over pre-applied antibiotic. The bandage self-degraded, appropriately, over 7 days despite extreme conditions (faecal slurry). Treatment was well-tolerated and clinical improvement was observed in animal mobility. This new class of bandage has promise for challenging topical situations in humans and other animals, especially away from controlled, sterile clinical settings where wounds urgently require protection from environmental and bacterial contamination.

The involvement of occupational health services prior to ill-health retirement in NHS staff in Scotland and predictors of re-employment.

OBJECTIVE: To assess the process, causes and outcomes of retirement because of ill-health in NHS staff in Scotland. Particular areas to be investigated include the involvement of occupational health services, access to rehabilitation and redeployment, current health, whether working again and to identify predictors of re-employment. METHOD: An ill-health retirement (IHR) questionnaire was mailed to 863 NHS staff awarded IHR benefits by the Scottish Public Pensions Agency between April 1998 and March 2000. RESULTS: In all, 49% of the 863 postal questionnaires were returned. The most common reasons for retiring were diseases of the musculoskeletal system (38%) and mental disorders (21%). Seventy-one percent of the participants reported their ill-health was partly or completely work related and 29% not work related. Ninety-two percent of NHS staff had attended an occupational health department prior to IHR. Twenty-three percent of participants had no contact with their line manager during their illness prior to retiral. Eighteen percent of individuals were offered the opportunity of working part-time and 15% offered alternative work. Seventeen percent of participants have obtained other work. Predictors of re-employment after IHR were: medical condition, managerial responsibility, improvement of health, wanting to work again, occupation and age at retirement. CONCLUSION: This is the first comprehensive study investigating NHS staff experiences of IHR in Scotland. This study illustrates the need for improved support and rehabilitation for ill-health care workers and that there is the potential to reduce levels of ill-health retirement.