Yawning and spontaneous blink rate (SBR) are two physiological reflexes which have been incompletely examined but one neurobiological step of these two behaviours seems, at least in part, dopamine‐dependent. The reference dopaminergic agonist, apomorphine hydrochloride (0.5, 1, and 2 micrograms kg‐1 s.c.), was compared with a placebo in a double‐blind latin‐square design, and was shown to induce yawning and increase SBR in a population of eight healthy volunteers. These two behavioral effects were not dose‐related. The individual SBR differences were correlated with the individual number of yawns for all the four treatments at the 10‐30 min interval. Thus, parallel yawning and SBR behaviour suggests a similar pharmacological mechanism. Apomorphine‐ induced yawning and blinking may be therefore of use in the evaluation of central dopaminergic pathways in man.

Preclinical research suggests that piracetam (a nootropic drug) may improve cognitive functions, but previous studies have failed to demonstrate a clear benefit for the treatment of Alzheimer's disease (AD). We report a 1-year, double-blind, placebo-controlled, parallel-group study with a high dose of piracetam (8 g/d per os) in 33 ambulant patients with early probable AD. Thirty subjects completed the 1-year study. No improvement occurred in either group, but our results support the hypothesis that long-term administration of high doses of piracetam might slow the progression of cognitive deterioration in patients with AD. The most significant differences concerned the recall of pictures series and recent incident and remote memory. The drug was well-tolerated.

Decompression sickness (DCS) is recognized as a multifactorial phenomenon depending on several individual factors, such as age, adiposity, and level of fitness. The detection of circulating venous bubbles is considered as a useful index for the safety of a decompression, because of the relationship between bubbles and DCS probability. The aim of this work was to study the effects of individual variables which can be assessed non invasively, on the grades of bubbles detected 60 min, after diving by means of Doppler monitoring, in a sample of 40 male recreational scuba divers. The variables investigated were: age, weight, maximal oxygen uptake (VO2max) and percentage of body fat (%BF). Bubble signals were graded according to the code of Spencer. The relationships between the bubble grades (BG) and the variables investigated were studied using two methods: the differences between the average values of each variable at each BG were analyzed by the Scheffe test. Then we performed the non-parametric Spearman correlation analysis. Significant differences (P < 0.05) were found (Scheffe test) between average values of the variables at grade 0 and 3 (age: P = 0.0323; weight: P = 0.0420; VO2max: P = 0.0484), except for %BF (P = 0.1697). Relationships with P < 0.01 were found (Spearman correlation) between BG and the variables: age: p = 0.486, P = 0.0024; weight: p = 0.463, P = 0.0039; VO2max: p = -0.481, P = 0.0027; except for %BF: p = 0.362, P = 0.0237. This work showed that bubble production after hyperbaric exposures depends on several individual factors. The effects of age, weight and VO2max are more significant than the effect of %BF. We concluded that to take into account such variables in decompression tables and diving computer programs should allow to adapt the decompression procedures to individual risk factors and reduce the DCS probability.

The influence of daily changes in sulfur dioxide (SO2) levels on the induction of respiratory symptoms was studied during the 1983-1984 winter in 450 children, aged 9 to 11 yr, living in the Gardanne coal-basin, France. In this area, SO2 originates mainly from a coal-fueled power plant. The mean SO2 level during the winter was 22 micrograms/m3 in low-pollution areas and 93 micrograms/m3 in polluted areas, with daily SO2 levels up to 356 micrograms/m3. Children completed a daily diary about respiratory symptoms. In the polluted communities only we demonstrated a significant association between daily SO2 levels (after controlling for temperature and respirable particle variations) and prevalence of upper and lower respiratory symptoms. However, in each polluted town, and for each respiratory symptom, there was no evidence for either a latency period or a delay in the effects of pollutants. Mean daily temperature was also closely correlated with upper and lower respiratory symptoms in most of the polluted and some low-pollution communities. In a second step, the prevalence of respiratory symptoms in each town was compared, during two 2-wk periods, with air pollution levels; higher prevalences were found during the pollution period. In conclusion, moderate daily changes in SO2 levels induce a significant but transient increase in the prevalence of respiratory symptoms in children.