No abstract

Objectives: Participants of ultramarathon events experience a complex interaction of psychophysiological stressors. Therefore, the purpose of this study was to investigate the role of trait emotional intelligence (trait EI) on mood states and serum cortisol responses to a 80.5km treadmill ultramarathon.Design: Twelve participants completed an 80.5km time-trial on a motorised treadmill in the fastest possible time.2 Methods: Participants' trait EI was measured prior to the trial. A mood state questionnaire was completed prior (baseline: within two weeks of treadmill ultramarathon), immediately prior (pre: within 30 min of commencing treadmill ultramarathon), at 40.25 km (halfway: during standardised 10 min rest period to allow for venous blood sampling) and on completion of 80.5 km (post: immediately on completion of treadmill ultramarathon), along with serum cortisol concentrations measured at the same time points.Results: Completion time was 09:00:18±01:14:07 (hh:mm:ss). Significant increase in serum cortisol and total mood disturbance (TMD) was observed throughout the treadmill ultramarathon (p<0.05). Participants with higher trait EI displayed a higher post cortisol concentration (p=0.01) with no change in TMD, compared to those with low trait EI who displayed a significant increase in TMD between pre and halfway (p=0.02). Conclusion:The treadmill ultramarathon elicited a significant increase in serum cortisol concentration, which was significantly greater in those with a higher trait EI. Those individuals with higher trait EI were more effective at managing their mood, with little change total mood disturbance and perceived effort compared to those with lower trait EI.

We describe a novel generic method to derive the unknown endogenous concentrations of analyte within complex biological matrices (e.g. serum or plasma) based upon the relationship between the immunoassay signal response of a biological test sample spiked with known analyte concentrations and the log transformed estimated total concentration. If the estimated total analyte concentration is correct, a portion of the sigmoid on a log-log plot is very close to linear, allowing the unknown endogenous concentration to be estimated using a numerical method. This approach obviates conventional relative quantification using an internal standard curve and need for calibrant diluent, and takes into account the individual matrix interference on the immunoassay by spiking the test sample itself. This technique is based on standard additions for chemical analytes. Unknown endogenous analyte concentrations within even 2-fold diluted human plasma may be determined reliably using as few as four reaction wells.

Measurement of cortisol in serum is used commonly as an indicator of stress and disease. Conventional analytical techniques have limited utility given that they remain largely laboratory based, they do not directly measure the deemed biologically active free cortisol, and there is no robust correlation between the free cortisol measurements within serum and saliva. It would therefore be desirable to measure both the free and total cortisol readily within the same matrix in a portable device in the field or at the bedside. This paper demonstrates the utility of a portable Raman approach to measure both the biological active free cortisol as well as total cortisol in human serum, compared to a laboratory-based chemiluminescence analysis technique. This alternative portable Raman method produced results that were consistent with results obtained from previous methods, which has the potential for further miniaturisation for point of test applications

Point of care monitoring of chemical biomarkers in real-time holds great potential in rapid disease diagnostics and precision medicine. However, monitoring is still rare in practice, as measurement of biomarkers...