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Piridoxilate, at the concentration of 120 mg/kg i.p. in rats, enhanced resistance of these animals to hypoxia (N2 : O2 3,2 %). The electrocorticogram (ECOG) is used to indicate the effectiveness of the drug in lowering the time of electrographic silence, on control (n=19) and pretreated rats (n=12). The ECOG was recorded also during the recovery period under pure oxygen. In pretreated rats, the ECOG records became flat in approximately 551 sec (versus 269 sec on the control group). The latent period of successive steps of cerebral anoxia were delayed in pretreated rats exposed to hypoxia. During the recovery period, piridoxilate seems to enhance the restoration of normal ECOG, as a function of the duration of hypoxia.

The authors have tried to consider EEG criteria applicable to fitness for diving. In a study of 90 professional divers, 37 (41%) displayed patterns susceptible of being interpreted as falling outside of strict normalcy. These patterns have sometimes been considered incompatible with diving, or even pathological by some authors. Considering the fact that these subjects were in good health, the value of these EEG signs is discussed in comparison with the literature. A general guideline is proposed placing subjects in three groups: fit, unfit, and questionable. In the last case, a final decision is taken in each individual case in agreement with the other medical examinations and based on the type of diving considered. Some explicit EEG criteria of definitive or temporary fitness and unfitness are proposed.

It was shown that oxygen at high pressure (OHP) induced epileptic seizures and pulmonary damages on mice. Dipropylacetate protected mice against nervous syndrome better than did dipropylacetamide. No significant pulmonary protection was observed with both drugs.

Five dogs and twelve rabbits were submitted to simulated diving at 6 ATA (compressed air) and 13-15 ATA (normoxic oxygen + nitrogen). Progressive decompressions were carried on for the first, rapid for the lasts. Motor nerve conduction velocity and nerve-muscle delays were measured. No variations could be observed neither for nerve conduction velocity nor for muscular and nerve action potentials. Nevertheless optic and electronic microscopy observations shew some nerve, neuronal and a few muscular alterations occuring during rapid decompression.