Validation of e-Celsius gastrointestinal telemetry system as measure of core temperature.

The main objective of this study was to validate gastrointestinal measurement with the e-Celsius® system composed of an ingestible electronic capsule and a monitor. Twenty-three healthy volunteers aged 18-59 years stayed at the hospital for 24 h under fasting conditions. They were only allowed for quiet activity and were asked to keep their sleeping habits. Subjects ingested a Jonah capsule and an e-Celsius® capsule, and a rectal probe and an esophageal probe were inserted. Mean temperature measured by the e-Celsius® device was lower than that measured by Vitalsense® (-0.12 ± 0.22°C; p < 0.001) and the rectal probe (-0.11 ± 0.03°C; p = 0.003) and higher than that measured by the esophageal probe (0.17 ± 0.05; p = 0.006). Mean difference (bias) and 95% confidence intervals between temperature of e-Celsius capsule, Vitalsense Jonah capsule, esophageal probe, and rectal probe were computed using Bland and Altman procedure. The magnitude of the measurement bias is significantly greater when comparing the e-Celsius® and the Vitalsense® device pair with any other device pairs containing the esophageal probe. Amplitude of confidence interval between the e-Celsius® system and the Vitalsense® system was 0.67°C. This amplitude was significantly lower than those of the esophageal probe-e-Celsius® pairing (0.83°C; p = 0.027), of the esophageal probe-Vitalsense (0.78°C; p = 0.046) and of the esophageal probe-rectal probe (0.83°C; p = 0.002). The statistical analysis did not reveal any effect of time on the amplitude of bias, whatever the device concerned. When comparing missing data rate of the e-Celsius® system (0.23 ± 0.15%) and the Vitalsense® devices (0.70 ± 0.11%) during the whole experiment, no differences was observed (p = 0.09). The e-Celsius® system could be used when a continuous following of internal temperature is needed.

Surgical declarative knowledge learning: concept and acceptability study.

Improving surgical training by means of technology assistance is an important challenge that aims to directly impact surgical quality. Surgical training includes the acquisition of two categories of knowledge: declarative knowledge (i.e. 'knowing what') and procedural knowledge (i.e. 'knowing how'). It is essential to acquire both before performing any particular surgery. There are currently many tools for acquiring procedural knowledge, such as simulators. However, few approaches or tools allow a trainer to formalize and record surgical declarative knowledge, and a trainee to have easy access to it. In this paper, we propose an approach for structuring surgical declarative knowledge according to procedural knowledge and based on surgical process modeling. A dedicated software application has been implemented. We evaluated the concept and the software usability on two procedures with different medical populations: endoscopic third ventriculostomy involving 6 neurosurgeons and preparation of a surgical table for craniotomy involving 4 scrub nurses. The results of both studies show that surgical process models could be a well-adapted approach for structuring and visualizing surgical declarative knowledge. The software application was perceived by neurosurgeons and scrub nurses as an innovative tool for managing and presenting surgical knowledge. The preliminary results show that the feasibility of the proposed approach and the acceptability and usability of the corresponding software. Future experiments will study impact of such an approach on knowledge acquisition.

The critical role of vestibular graviception during cognitive-motor development.

Earth's gravity acts both as a mechanical stimulus on the body and as a sensory stimulus to the vestibular organ, which is transmitted into the brain. The vestibular system has been recently highlighted as the cornerstone of the multisensory cortex and of the dorsal hippocampus related to spatial cognition. Consequently, we have hypothesized that the vestibular sensory perception of gravity by the otoliths might also play a crucial role during the first stages of development in both sensorimotor and cognitive functions and the construction and perception of the 'self' and related functions of orientation and navigation. We have investigated an original mouse model (Head Tilted mice, B6Ei.GL-Nox3het/J) suffering from a selective congenital absence of vestibular otolithic gravisensors. We report that mouse pups suffered from a delay in the acquisition of sensorimotor reflexes, spatial olfactory guidance, path integration, and ultrasonic communication, while maternal care remained normal. We demonstrate that development has a critical period dependent on the vestibular otolithic sensory perception of gravity, probably temporally between the somesthetic and visual critical periods. The symptoms expressed by the congenital otolithic-deficient mice are similar to validated mouse models of autism and highlight the significance of vestibular graviception in the pathophysiology of development.

Protein intake, calcium balance and health consequences.

High-protein (HP) diets exert a hypercalciuric effect at constant levels of calcium intake, even though the effect may depend on the nature of the dietary protein. Lower urinary pH is also consistently observed for subjects consuming HP diets. The combination of these two effects was suspected to be associated with a dietary environment favorable for demineralization of the skeleton. However, increased calcium excretion due to HP diet does not seem to be linked to impaired calcium balance. In contrast, some data indicate that HP intakes induce an increase of intestinal calcium absorption. Moreover, no clinical data support the hypothesis of a detrimental effect of HP diet on bone health, except in a context of inadequate calcium supply. In addition, HP intake promotes bone growth and retards bone loss and low-protein diet is associated with higher risk of hip fractures. The increase of acid and calcium excretion due to HP diet is also accused of constituting a favorable environment for kidney stones and renal diseases. However, in healthy subjects, no damaging effect of HP diets on kidney has been found in either observational or interventional studies and it seems that HP diets might be deleterious only in patients with preexisting metabolic renal dysfunction. Thus, HP diet does not seem to lead to calcium bone loss, and the role of protein seems to be complex and probably dependent on other dietary factors and the presence of other nutrients in the diet.