Safety and Efficacy of Silver-Coated Biomaterials in vivo

Overtreatment and overuse of antibiotics in healthcare and agricultural settings have contributed to the selective pressure on bacterial strains to develop resistance. Resistance can develop as a result of mutations and subsequent resistance genes that allow bacteria to survive against antibiotics. Novel silver-oxide coatings were developed and were previously demonstrated to prevent adhesion of gram-negative bacteria (Escherichia Coli and Pseudomonas Aeruginosa) to the disc, but did not prevent gram-positive bacterial adherence (Streptococcus Aureus). In order to determine whether the silver-oxide coatings are bacterial static and may be preventing progression to biofilm formation, in vivo analysis of S. Aureus attached to discs was performed. Results show that the stages of biofilm formation and infiltrating immune cells were identifiable by scanning electron microscopy (SEM). These data will be used as the foundation to compare to S. Aureus and other gram-positive bacteria attachment to coated discs

Safety of Silver Oxide Coated Biomaterials in Mice

It has been demonstrated that silver oxide coatings designed by our collaborators are able to prevent E. coli and P. aeruginosa attachment to biomaterials in vivo. These findings demonstrate that such coatings show promise in preventing the development of biofilm on biodevices. However, it is unknown if the use of silver oxide in this fashion is toxic in vivo. The goal of this project was to determine whether our silver oxide coatings are safe to use in vivo. To assess the toxicity of our silver oxide formula, mice were implanted with either silver oxide coated titanium discs or uncoated titanium discs. Blood samples were drawn at pre-determined time points in order to determine AST and ALT levels via ELISA assay. Preliminary results demonstrate no acute liver injury after 3 months with the discs. However, it appears as if silver is accumulating in tissues over time. Histological analysis at one year shows evidence of simple steatosis in livers. While our group is continuing to investigate the safety and efficacy of these silver oxides coatings in vivo, preliminary data shows that they may have some toxicity and the silver oxide formula may need to be altered and retested

PHIL photoinjector test line

LAL is now equiped with its own platform for photoinjectors tests and Research and Developement, named PHIL (PHotoInjectors at LAL). This facility has two main purposes: push the limits of the photoinjectors performances working on both the design and the associated technology and provide a low energy (MeV) short pulses (ps) electron beam for the interested users. Another very important goal of this machine will be to provide an opportunity to form accelerator physics students, working in a high technology environment. To achieve this goal a test line was realised equipped with an RF source, magnets and beam diagnostics. In this article we will desrcibe the PHIL beamline and its characteristics together with the description of the first two photoinjector realised in LAL and tested: the ALPHAX and the PHIN RF Guns

The effect of smoking on the duration of life with and without disability, Belgium 1997-2011

Background: Smoking is the single most important health threat yet there is no consistency as to whether non-smokers experience a compression of years lived with disability compared to (ex-)smokers. The objectives of the manuscript are (1) to assess the effect of smoking on the average years lived without disability (Disability Free Life Expectancy (DFLE)) and with disability (Disability Life Expectancy (DLE)) and (2) to estimate the extent to which these effects are due to better survival or reduced disability in never smokers. Methods. Data on disability and mortality were provided by the Belgian Health Interview Survey 1997 and 2001 and a 10 years mortality follow-up of the survey participants. Disability was defined as difficulties in activities of daily living (ADL), in mobility, in continence or in sensory (vision, hearing) functions. Poisson and multinomial logistic regression models were fitted to estimate the probabilities of death and the prevalence of disability by age, gender and smoking status adjusted for socioeconomic position. The Sullivan method was used to estimate DFLE and DLE at age 30. The contribution of mortality and of disability to smoking related differences in DFLE and DLE was assessed using decomposition methods. Results: Compared to never smokers, ex-smokers have a shorter life expectancy (LE) and DFLE but the number of years lived with disability is somewhat larger. For both sexes, the higher disability prevalence is the main contributing factor to the difference in DFLE and DLE. Smokers have a shorter LE, DFLE and DLE compared to never smokers. Both higher mortality and higher disability prevalence contribute to the difference in DFLE, but mortality is more important among males. Although both male and female smokers experience higher disability prevalence, their higher mortality outweighs their disability disadvantage resulting in a shorter DLE. Conclusion: Smoking kills and shortens both life without and life with disability. Smoking related disability can however not be ignored, given its contribution to the excess years with disability especially in younger age groups

Probing the urea dependence of residual structure in denatured human α-lactalbumin

Backbone 15N relaxation parameters and 15N–1HN residual dipolar couplings (RDCs) have been measured for a variant of human α-lactalbumin (α-LA) in 4, 6, 8 and 10 M urea. In the α-LA variant, the eight cysteine residues in the protein have been replaced by alanines (all-Ala α-LA). This protein is a partially folded molten globule at pH 2 and has been shown previously to unfold in a stepwise non-cooperative manner on the addition of urea. 15N R2 values in some regions of all-Ala α-LA show significant exchange broadening which is reduced as the urea concentration is increased. Experimental RDC data are compared with RDCs predicted from a statistical coil model and with bulkiness, average area buried upon folding and hydrophobicity profiles in order to identify regions of non-random structure. Residues in the regions corresponding to the B, D and C-terminal 310 helices in native α-LA show R2 values and RDC data consistent with some non-random structural propensities even at high urea concentrations. Indeed, for residues 101–106 the residual structure persists in 10 M urea and the RDC data suggest that this might include the formation of a turn-like structure. The data presented here allow a detailed characterization of the non-cooperative unfolding of all-Ala α-LA at higher concentrations of denaturant and complement previous studies which focused on structural features of the molten globule which is populated at lower concentrations of denaturant