Nicotine has wellknown, unpleasant side effects, e.g., transient dizziness, nausea, and nicotine-induced nystagmus (NIN). To investigate factors influencing these effects, we addressed three questions: (1) Is the intensity of dizziness, nausea, NIN, and unsteadiness dependent on nicotine dosage? (2) Does the intensity of perceptual, ocular motor, vegetative effects, and postural imbalance correlate? (3) Do visual or vestibular motion stimuli produce and/or aggravate distressing dizziness and nausea? Sixty healthy non-smokers or occasional smokers participated; 40 were tested once before and six times after application of a nicotine nasal spray in doses of 1 mg or 2 mg with or without motion stimulation; 20 received a placebo nasal spray. Plasma nicotine concentrations were significantly related to nicotine dosage. Dizziness, nausea, NIN, and unsteadiness also depended on the nicotine dosage (p < 0.01).Nicotine blood concentration was a better predictor for the temporal dependence of nystagmus than nicotine dosage. Dizziness correlated highly with nausea (R = 0.63, p < 0.001). The degree of nicotine-induced nausea significantly correlated with postural imbalance. The time course of postural sway differed according to nicotine dosage and gender: for women, there was no clear relationship between sway magnitude and nicotine dosage, while men showed increased sway with higher dosage. Motion stimulation increased nicotine-induced dizziness and nausea, but did not significantly influence NIN or postural imbalance. Our data support the view that all measured adverse effects reflect dose-dependent nicotine-induced vestibular dysfunction. Additional motion stimulation aggravates dizziness and nausea, i.e., nicotine increases sensitivity to motion sickness.

Sterile inflammatory reactions of varying degrees are a rare, but not uncommon, complication after intraocular lens implantation. At present we still do not know the cause of these processes, but we consider two chemical substances contained in the lens at least as risk factors for them: monomeric methyl methacrylate, which is present in any lens made from polymethyl methacrylate (Perspex), and ethylene oxide, an extremely toxic agent, which is absorbed by the lens during sterilization with this gas. Gas chromatographic investigations show that under sterilization of intraocular lenses by ⁶⁰Co radiation the amount of monomeric methyl methacrylate in the lens can be reduced drastically. Also, any contamination of the lens by ethylene oxide is avoided. Therefore, at least two important arguments speak in favor of this alternative sterilization technique.

It is theoretically possible that lesions generated by a Q-switched Nd-YAG laser could lead to chemical changes in polymethylmethacrylate (PMMA) intraocular lenses. These changes could be of clinical relevance. Therefore, we measured the residual monomer content of intraocular lenses before and after generation of lesions by means of a short-pulsed Nd-YAG laser. Despite the explosive destruction of the lens surface caused by this type of laser, there is no measurable release of monomer in the sense of a depolymerization of the PMMA material, even when over 100 lesions are generated. The lesions generated on intraocular PMMA lenses with the Nd-YAG laser are predominantly of a mechanical nature and include the chipping away of small particles from the intraocular lens.

Le film de Roberto Benigni, La Vie est belle, a pour thème principal la survie d’un enfant, protégé par son père, dans un camp de concentration nazi. Le succès international du film pose, à côté de la simple critique sur le traitement burlesque du thème, la question des mécanismes qui permettent au spectateur de se réjouir de ce qui peut apparaître comme la mise en scène d’un véritable déni de la réalité.

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