Gender differences in whole body fat oxidation kinetics during exercise

Introduction Discrepancies appear in studies comparing fat oxidation between men and women during exercise (1). Therefore, this study aimed to quantitatively describe and compare whole body fat oxidation kinetics between genders during exercise using a sinusoidal model (SIN) (2). Methods Twelve men and 11 women matched for age, body mass index (23.4±0.6 kg.m-2 and 21.5±0.8 kg.m-2, respectively) and aerobic fitness [maximal oxygen uptake ( ) (58.5±1.6 mL.kg FFM-1.min-1 and 55.3±2.0 mL.kg FFM-1.min-1, respectively) and power output ( ) per kilogram of fat-free mass (FFM)] performed submaximal incremental tests (Incr) with 5-min stages and 7.5% increment on a cycle ergometer. Respiratory and HR values were averaged over the last 2 minutes of each stage. All female study participants were eumenorrheic, reported regular menstrual cycles (28.6 ± 0.8 days) and were not taking oral contraceptives (OC) or other forms of exogenous ovarian hormones. Women were studied in the early follicular phase (FP) of their menstrual cycle (between days 3 and 8, where day 1 is the first day of menses). Fat oxidation rates were determined using indirect calorimetry and plotted as a function of exercise intensity. The SIN model (2), which includes three independent variables (dilatation, symmetry, translation), was used to mathematically describe fat oxidation kinetics and to determine the intensity (Fatmax) eliciting the maximal fat oxidation (MFO). Results During Incr, women exhibited greater fat oxidation rates from 35 to 85% , MFO (6.6 ± 0.9 vs. 4.5 ± 0.3 mgkg FFM-1min-1) and Fatmax (58.1 ± 1.9 vs. 50.0 ± 2.7% ) (P<0.05) than men. While men and women showed similar global shapes of fat oxidation kinetics in terms of dilatation and symmetry (P>0.05), the fat oxidation curve tended to be shifted towards higher exercise intensities in women (rightward translation, P=0.08). Conclusion These results showed that women, eumenorrheic, not taking OC and tested in FP, have a greater reliance on fat oxidation than men during submaximal exercise, but they also indicate that this greater fat oxidation is shifted towards higher exercise intensities in women compared with men. References 1. Blaak E. Gender differences in fat metabolism. Curr Opin Clin Nutr Metab Care 4: 499-502, 2001. 2. Cheneviere X, Malatesta D, Peters EM, and Borrani F. A mathematical model to describe fat oxidation kinetics during graded exercise. Med Sci Sports Exerc 41: 1615-1625, 2009.

Temporal dynamics of auditory what and where processing in humans

Recent evidence suggests the human auditory system is organized,like the visual system, into a ventral 'what' pathway, devoted toidentifying objects and a dorsal 'where' pathway devoted to thelocalization of objects in space w1x. Several brain regions have beenidentified in these two different pathways, but until now little isknown about the temporal dynamics of these regions. We investigatedthis issue using 128-channel auditory evoked potentials(AEPs).Stimuli were stationary sounds created by varying interaural timedifferences and environmental real recorded sounds. Stimuli ofeach condition (localization, recognition) were presented throughearphones in a blocked design, while subjects determined theirposition or meaning, respectively.AEPs were analyzed in terms of their topographical scalp potentialdistributions (segmentation maps) and underlying neuronalgenerators (source estimation) w2x.Fourteen scalp potential distributions (maps) best explained theentire data set.Ten maps were nonspecific (associated with auditory stimulationin general), two were specific for sound localization and two werespecific for sound recognition (P-values ranging from 0.02 to0.045).Condition-specific maps appeared at two distinct time periods:;200 ms and ;375-550 ms post-stimulus.The brain sources associated with the maps specific for soundlocalization were mainly situated in the inferior frontal cortices,confirming previous findings w3x. The sources associated withsound recognition were predominantly located in the temporal cortices,with a weaker activation in the frontal cortex.The data show that sound localization and sound recognitionengage different brain networks that are apparent at two distincttime periods.References1. Maeder et al. Neuroimage 2001.2. Michel et al. Brain Research Review 2001.3. Ducommun et al. Neuroimage 2002.

Simulated Patient as Co-facilitators: Benefits and Challenges of the Interprofessional Team OSCE (Submission #9350).

Hypothesis: The quality of care for chronic patients depends on the collaborative skills of the healthcare providers.1,2 The literature lacks reports of the use of simulation to teach collaborative skills in non-acute care settings. We posit that simulation offers benefits for supporting the development of collaborative practice in non-acute settings. We explored the benefits and challenges of using an Interprofessional Team - Objective Structured Clinical Examination (IT-OSCE) as a formative assessment tool. IT-OSCE is an intervention which involves an interprofessional team of trainees interacting with a simulated patient (SP) enabling them to practice collaborative skills in non-acute care settings.5 A simulated patient are people trained to portray patients in a simulated scenario for educational purposes.6,7 Since interprofessional education (IPE) ultimately aims to provide collaborative patient-centered care.8,9 We sought to promote patient-centeredness in the learning process. Methods: The IT-OSCE was conducted with four trios of students from different professions. The debriefing was co-facilitated by the SP with a faculty. The participants were final-year students in nursing, physiotherapy and medicine. Our research question focused on the introduction of co-facilitated (SP and faculty) debriefing after an IT-OSCE: 1) What are the benefits and challenges of involving the SP during the debriefing? and 2) To evaluate the IT-OSCE, an exploratory case study was used to provide fine grained data 10, 11. Three focus groups were conducted - two with students (n=6; n=5), one with SPs (n=3) and one with faculty (n=4). Audiotapes were transcribed for thematic analysis performed by three researchers, who found a consensus on the final set of themes. Results: The thematic analysis showed little differentiation between SPs, student and faculty perspectives. The analysis of transcripts revealed more particularly, that the SP's co-facilitation during the debriefing of an IT-OSCE proved to be feasible. It was appreciated by all the participants and appeared to value and to promote patient-centeredness in the learning process. The main challenge consisted in SPs feedback, more particularly in how they could report accurate observations to a students' group rather than individual students. Conclusion: In conclusion, SP methodology using an IT-OSCE seems to be a useful and promising way to train collaborative skills, aligning IPE, simulation-based team training in a non-acute care setting and patient-centeredness. We acknowledge the limitations of the study, especially the small sample and consider the exploration of SP-based IPE in non-acute care settings as strength. Future studies could consider the preparation of SPs and faculty as co-facilitators. References: 1. Borrill CS, Carletta J, Carter AJ, et al. The effectiveness of health care teams in the National Health Service. Aston centre for Health Service Organisational Research. 2001. 2. Reeves S, Lewin S, Espin S, Zwarenstein M. Interprofessional teamwork for health and social care. Oxford: Wiley-Blackwell; 2010. 3. Issenberg S, McGaghie WC, Petrusa ER, Gordon DL, Scalese RJ. Features and uses of high-fidelity medical simulations that lead to effective learning - a BEME systematic review. Medical Teacher. 2005;27(1):10-28. 4. McGaghie W, Petrusa ER, Gordon DL, Scalese RJ. A critical review of simulation-based medical education research: 2003-2009. Medical Education. 2010;44(1):50-63. 5. Simmons B, Egan-Lee E, Wagner SJ, Esdaile M, Baker L, Reeves S. Assessment of interprofessional learning: the design of an interprofessional objective structured clinical examination (iOSCE) approach. Journal of Interprofessional Care. 2011;25(1):73-74. 6. Nestel D, Layat Burn C, Pritchard SA, Glastonbury R, Tabak D. The use of simulated patients in medical education: Guide Supplement 42.1 - Viewpoint. Medical teacher. 2011;33(12):1027-1029. Disclosures: None (C) 2014 by Lippincott Williams & Wilkins, Inc.

Performance comparison of two commercial BGO-based PET/CT scanners using NEMA NU 2-2001.

Combined positron emission tomography and computed tomography (PET/CT) scanners play a major role in medicine for in vivo imaging in an increasing number of diseases in oncology, cardiology, neurology, and psychiatry. With the advent of short-lived radioisotopes other than 18F and newer scanners, there is a need to optimize radioisotope activity and acquisition protocols, as well as to compare scanner performances on an objective basis. The Discovery-LS (D-LS) was among the first clinical PET/CT scanners to be developed and has been extensively characterized with older National Electrical Manufacturer Association (NEMA) NU 2-1994 standards. At the time of publication of the latest version of the standards (NU 2-2001) that have been adapted for whole-body imaging under clinical conditions, more recent models from the same manufacturer, i.e., Discovery-ST (D-ST) and Discovery-STE (D-STE), were commercially available. We report on the full characterization both in the two- and three-dimensional acquisition mode of the D-LS according to latest NEMA NU 2-2001 standards (spatial resolution, sensitivity, count rate performance, accuracy of count losses, and random coincidence correction and image quality), as well as a detailed comparison with the newer D-ST widely used and whose characteristics are already published.