A comparison of contralateral acoustic suppression of transient-evoked otoacoustic emissions measured in a group of individuals at risk of mild traumatic brain injury through participation in contact sports and a group of controls.

This small scale preliminary study aims to assess whether athletes participating in sports with a high occurrence of sub-concussive injury present with reduced contralateral acoustic suppression (CAS) of transient-evoked otoacoustic emissions (TEOAEs). CAS TEOAEs has potential to be used as an objective assessment of concussion, either at the “pitch-side” or as part of a “return-to-play” protocol. Previous studies have shown reduced CAS TEOAEs in subjects experiencing auditory symptoms post-concussive injury (e.g. Nölle et al, 2004). However, the effect of repeated sub-concussive injuries on CAS TEOAEs in participants with no auditory symptoms is less well understood, though it has important implications for the use of CAS TEOAEs in sports-related concussion assessment. CAS TEOAEs was measured in accordance with the test paradigm described by Hood et al (1996). TEOAEs were recorded in response to 60 dB p.e. SPL clicks with and without a 65 dB SPL broadband noise presented to the contralateral ear. Measurements were made from both ears of nine athletes who regularly play sport with a high occurrence of sub-concussive injury and fifteen control subjects who had not previously played such sports. For each subject four CAS TEOAEs measurements were obtained. These were CAS TEOAEs in the (i) right and the (ii) left ear; (iii) the sum of CAS TEOAEs obtained in both ears; and (iv) the magnitude of the difference in CAS TEOAE between the right and left ears. Results showed no significant difference between the athlete and control group for all four measures of CAS TEOAEs. In addition, results showed large inter-subject variability in CAS TEOAEs in both groups. These preliminary findings have implications for the application of CAS TEOAEs in the assessment of sports-related concussion. First, CAS TEOAEs does not appear to be sensitive to cumulative sub-concussive injury, and second, the use of individual baseline measurements is indicated, rather than population-based normative data

Label-free measuring and mapping of binding kinetics of membrane proteins in single living cells

Membrane proteins (MPs) mediate a variety of cellular responses to extracellular signals. While MPs are intensely studied for their values as disease biomarkers and therapeutic targets, in situ investigation of binding kinetics of MPs with their ligands has been a challenge. Traditional approaches isolate MPs and then study them ex situ, which does not accurately reflect their native structures and functions. We present here a label-free plasmonic microscopy method to map the local binding kinetics of MPs in their native environment. This new analytical method can perform simultaneous plasmonic and fluorescence imaging, thus making it possible to combine the strengths of both label-based and label-free techniques in one system. Using this method, we have determined the distribution of MPs on the surface of single cells, and the local binding kinetic constants of different MPs. Furthermore, we have studied the polarization of the MPs on the cell surface during chemotaxis

Chronic kidney disease and premature ageing

hronic kidney disease (CKD) shares many phenotypic similarities with other chronic diseases, including heart failure, chronic obstructive pulmonary disease, HIV infection and rheumatoid arthritis. The most apparent similarity is premature ageing, involving accelerated vascular disease and muscle wasting. We propose that in addition to a sedentary lifestyle and psychosocial and socioeconomic determinants, four major disease-induced mechanisms underlie premature ageing in CKD: an increase in allostatic load, activation of the 'stress resistance response', activation of age-promoting mechanisms and impairment of anti-ageing pathways. The most effective current interventions to modulate premature ageing—treatment of the underlying disease, optimal nutrition, correction of the internal environment and exercise training—reduce systemic inflammation and oxidative stress and induce muscle anabolism. Deeper mechanistic insight into the phenomena of premature ageing as well as early diagnosis of CKD might improve the application and efficacy of these interventions and provide novel leads to combat muscle wasting and vascular impairment in chronic diseases