Ultrastructural modifications in the mitochondria of hypoxia-adapted Drosophila melanogaster.

Chronic hypoxia (CH) occurs under certain physiological or pathological conditions, including in people who reside at high altitude or suffer chronic cardiovascular or pulmonary diseases. As mitochondria are the predominant oxygen-consuming organelles to generate ATP through oxidative phosphorylation in cells, their responses, through structural or molecular modifications, to limited oxygen supply play an important role in the overall functional adaptation to hypoxia. Here, we report the adaptive mitochondrial ultrastructural modifications and the functional impacts in a recently generated hypoxia-adapted Drosophila melanogaster strain that survives severe, otherwise lethal, hypoxic conditions. Using electron tomography, we discovered increased mitochondrial volume density and cristae abundance, yet also cristae fragmentation and a unique honeycomb-like structure in the mitochondria of hypoxia-adapted flies. The homeostatic levels of adenylate and energy charge were similar between hypoxia-adapted and naïve control flies and the hypoxia-adapted flies remained active under severe hypoxia as quantified by negative geotaxis behavior. The equilibrium ATP level was lower in hypoxia-adapted flies than those of the naïve controls tested under severe hypoxia that inhibited the motion of control flies. Our results suggest that the structural rearrangement in the mitochondria of hypoxia-adapted flies may be an important adaptive mechanism that plays a critical role in preserving adenylate homeostasis and metabolism as well as muscle function under chronic hypoxic conditions.

Evaluating training for a simulated team in complex whole procedure simulations in the endovascular suite.

INTRODUCTION: Simulators supporting the development of technical skills for complex procedures are gaining prominence. Safe performance of complex procedures requires effective team interactions. Our research group creates 'whole' procedure simulations to produce the psychological fidelity of clinical settings. Recruitment of real interventional team (IT) members has proved challenging. Actors as a simulated team are expensive. We hypothesised that medical students and trainees in a vascular unit could authentically portray members of the endovascular suite for carotid stenting. METHODS: This paper describes the evaluation of a training programme for a simulated IT. Participants rated the extent to which programmes objectives were met and realism of simulations. Researchers' field notes provided insight into strengths and weaknesses of the programme. RESULTS: Seven members from the vascular unit undertook training. Learning objectives were largely met. Nineteen simulations with 13 interventionalists were performed. Realism levels were at least moderate. Simulated IT members reported increased understanding of teamwork and roles in the endovascular suite. DISCUSSION: A simulated IT proved feasible. Authentic psychological fidelity complemented the physical fidelity of the simulated suite. Although there were areas for development in training, this approach might contribute considerably to interventionalist training and increase knowledge and skills of vascular trainees and medical students.