[16th century: suffering and disease on the way to great discoveries; from Lisbon to the Moluccas and to Japan].

It is known that plague epidemics and pandemics spread both by sea and by land. However, in the 16th century an entire "hidden face" of the continent was discovered and opened thanks to the Portuguese. It is noteworthy that just as Francis I or the Dutch, Yersinia pestis did not respect the longitudinal limits set out by the treaties of Tordessillas and Saragossa.

[Alcyonidium gelatinosum (L.) (Bryozoa) and cutaneous hypersensitivity reactions. Preliminary results of an experimental study].

The appearance of acute eczematous dermatitis in fishermen from the estuary of the Seine, about which the responsibility of Alcyonidium gelatinosum (L.) is still under discussion, led us to estimate the ability of this Bryozoa to induce cutaneous responses of delayed hypersensitivity. Intradermal tests carried out in guinea-pigs after subcutaneous, respiratory or percutaneous sensitization, gave evidence of a clear allergenic ability of this alcyonelline.

[Variation of plasmatic adenosine 3'', 5-cyclic monophosphate in irradiated-enterectomised dogs (author's transl)].

In the irradiated dog at different doses 250-400 R., a level plasma AMPc rise has been shown since the fourth hour with a maximum at 24 hours, returning to normal values about the thirtieth day. In irradiated at 250-300 R and secondarily enterectomised animals, nucleotide level rises 24 hours later, however this phenomenon is less intensive and later irradiated at 350 and 400 R.

[Evidence of benzo-3, 4-pyrene in the water and organic sediments of briny pools of polynesian atolls. Biotic and abiotic factors].

The presence of 3,4-benzopyrene is reported in samples of water and sediments from three briny ponds free from pollution of exogenous origin belonging to three different atolls of Polynesia. The synthesis of this hydrocarbon seems to be dependent on the presence of abundant phytoplancton and of bacterial flora.

[Histoenzymologic study of anticholinesterase activity of ciguatoxic extracts of Ceochetus striatus (Gunther) and Plectrompus leopardus].

The use of histo-enzymological techniques for visualizing the cholinesterasic spots on the motory plate is turned to account by the authors to point out the inhibition of the cholinesterasic processes, by some fractions of the ciguatoxins at the level of the neuro-mucular synapsis. The results obtained confirm, on one hand, the efficiency of the method to test the anti-cholinesterasic activity of some fractions of the ciguateric extracts, and, on the other hand, enable the establishment of the fact that even clinically non toxic individuals from fishspecies, dwelling in tropical coral biotops, can provoke a slightly marked but real inhibition of the cholinesterases, provided the contact between the fish extract and the neuro-motory plate is long enough in time. This observation reinforces the thesis of the ecological origin of the toxins along the alimentary chain of the reef biocoenosis.

[Proceedings: Interrelations between cholinergic and monoaminergic mechanisms in the determinism of spontaneous electrical activity in the central nervous system of scorpion (author's transl)].

Spontaneous electrical activity of the cerebral nervous system of Scorpion is characterized by potentials of 30 muV, and of average frequency varying between 200 et 400 impulses/min. This activity is enhanced by acetylcholine, and inhibited by adrenaline, nor-adrenaline, and serotonine, from a pharmacological study, it is assumed that spontaneous electrical activity of cerebral nervous system is due to cholinergic neurons, and antagonized by a serotoninergic system.

[Ciguatera: neurophysiological demonstration of toxicity of several ciquatoxic fractions].

Raw extracts from one Polynesian, frequently ciguatera-inducing fish were submitted to fractional distillation by means of a chromatographic process using a silicic acid column. Three out of the seven fractions split this way exhibited either anticholinesterasic properties, or directly toxic properties at the muscle-cell level: fraction 5, which is not antagonized by atropine, presumably accounts for this direct action, as it competes with calcium at membrane sites. Fraction 6 appears to be more specially responsible for the anticholinesterasic action.

[Ciguatera: neurophysiologic and histoenzymologic studies of several fractions of ciguatoxic extracts].

Two fractions of ciguatoxic extracts were isolated by chromatography. The first showed anticholinesterasic properties, while the other acted directly on the muscular fibre. These findings were histoenzymologically confirmed.