[The effects of hypnosis by virtual reality on tolerance to flexible bronchoscopy]. / Effets de l'hypnose par réalité virtuelle sur la tolérance de la bronchoscopie flexible.

INTRODUCTION: Patients often perceive flexible bronchoscopy as an unpleasant procedure. The aim of this study was to investigate the effect of virtual reality (VR) hypnosis on tolerance to flexible bronchoscopy. MATERIALS AND METHODS: We conducted a prospective, randomized, controlled, monocentric study comparing flexible bronchoscopy with VR-induced hypnosis to the usual procedure. Patient tolerance was evaluated using a visual analogue scale (VAS), the state-trait anxiety inventory (STAI) before and after the procedure and, finally, willingness to repeat the examination under the same conditions (WTR). RESULTS: Among the 70 patients included, 34 were randomized to the VR hypnosis group and 36 to the control group. There was no difference between the 2 groups in terms of modification of the pre-/post-bronchoscopy VAS for anxiety, pain, cough, choking, nausea and overall discomfort, or modification of the STAI score and WTR. Subgroup analysis among patients who were more anxious before the procedure revealed a trend toward reduced anxiety in the VR hypnosis group. CONCLUSION: This study did not observe any effect of VR hypnosis on the tolerance of patients during routine flexible bronchoscopy. However, VR hypnosis may be beneficial in patients with higher anxiety score before bronchoscopy, a hypothesis that needs to be confirmed by further studies with a larger number of subjects.

Self-assembly of influenza hemagglutinin: studies of ectodomain aggregation by in situ atomic force microscopy.

We have used in situ tapping mode atomic force microscopy (AFM) to study the structural morphology of two fragments of the influenza hemagglutinin protein bound to supported bilayers. The two proteins that we studied are the bromelain-cleaved hemagglutinin (BHA), corresponding to the full ectodomain of the hemagglutinin protein, and FHA2, the 127 amino acid N-terminal fragment of the HA2 subunit of the hemagglutinin protein. While BHA is water soluble at neutral pH and is known to bind to membranes via specific interactions with a viral receptor, FHA2 can only be solubilized in water with an appropriate detergent. Furthermore, FHA2 is known to readily bind to membranes at neutral pH in the absence of a receptor. Our in situ AFM studies demonstrated that, when bound to supported bilayers at neutral pH, both these proteins are self-assembled as single trimeric molecules. In situ acidification resulted in further lateral association of the FHA2 without a large perturbation of the bilayer. In contrast, BHA remained largely unaffected by acidification, except in areas of exposed mica where it is aggregated. Remarkably, these results are consistent with previous observations that FHA2 promotes membrane fusion while BHA only induces liposome leakage at low pH. The results presented here are the first example of in situ imaging of the ectodomain of a viral envelope protein allowing characterization of the real-time self-assembly of a membrane fusion protein.