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Biomedical subjects

R Bagnis

Publications and source records attributed to R Bagnis.

At least 37 records · Page 2Linked to original sources
PubMed1970

Problems of toxicants in marine food products. 1. Marine biotoxins.

The expansion of marine fisheries into tropical waters, which is now occurring, will increase the risks of widespread poisonings because of the abundance of biotoxins in warm-water organisms. However, toxic marine organisms are not only a health hazard but also a possible source of new pharmaceutical products.A classification of marine intoxicants is given in this paper with special reference to the oral biotoxins which will be of primary concern in the expansion of warm-water fisheries. The biotoxins are both invertebrate (e.g., molluscs, arthropods) and vertebrate (mostly fishes) in origin. Biotoxications of vertebrate origin may be caused by the muscles, the gonads or the blood of certain fishes or by special poison glands not equipped with traumagenic devices. (Venomous fishes, having poison glands and traumagenic spines, etc., are of no direct concern as oral intoxicants.)The ichthyosarcotoxic fishes, in which the flesh is poisonous, appear to constitute the most significant health hazard. A list of fishes reported as causing ciguatera poisoning (one of the most serious and widespread forms of ichthyosarcotoxism) is included in this paper.

Animals↗
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[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. It revealed a quaternary ammonium ion in its 6-2 sub-fraction. Fraction 7 shows the same properties as fraction 6, but on a smaller scale.

Action Potentials↗
PubMedDate not supplied

[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.

Animals↗
PubMedDate not supplied

[Ciguatoxin and edible reef fishes].

Referring to the various human and animal clinical response to consumption of reef fish, the authors precise the importance of ingested dose and the role of cumulative effects. They point out the arbitrary character of distinguishing poisonous and edible fish of the same species. At the light of these data they find ciguatoxin in edible fish from known latent ciguateric potential species in atoxic areas. Therefore ciguatoxin does appear as a natural biotoxin permanently produced in most of the polynesian coral reefs ecosystems. The occurence of clinical disorders by men and animals results from a sudden increase of its production following biological transitory modification of some coral reef biota.

Animals↗
PubMedDate not supplied

[Comparative immunological study of protein extracts of poisonous and non-poisonous fishes (author's transl)].

Suggesting an immunologic participation in the pathogeny of the ciguateric syndroms, the authors have prepared a proteic antigen from the flesh of poisonous and edible fish of the same species. They have shown that there is a total common antigenicity between toxic and non toxic extracts. They suggest a new immunologic approach, in the matter of intoxication by ciguateric fish.

Animals↗
PubMedDate not supplied

[Evaluation of the efficacy of mannitol in the treatment of ciguatera in French Polynesia].

Up till now, in the French Polynesia and in New Caledonia, people showing ciguatera intoxication receive a standard treatment: calcium + vitamins B6 and C by intravenous way and in addition, some drugs arriving to cure some symptomatic manifestations. In 1988, an investigation carried out in Majuro, Marshall Islands concluded that intravenous mannitol is efficient in the treatment of serious intoxications with suspecting cerebral oedema. Since, such a treatment has been utilized with success in several endemic areas. Our therapeutic evaluation was arrived to determine whether mannitol's efficiency is higher than the standard treatment in the ciguatera intoxications of mean seriousness. This investigation was carried out on two randomized groups: The first one receiving mannitol (250 cc intravenous at 20% injected in 1 h) the second one receiving the standard treatment (intravenous perfusion glucose serum 250 cc with 1 g of vitamins C, 250 mg of vitamin B6 and 1 g of calcium gluconate injected in 1 h). Seriousness of clinical status was evaluated according to a scale of score from 0 to 50, based on the importance of the clinical manifestations paresthesia, aches, asthenia, cardiovascular and digestive signs. Only patients getting a score at least 20 were included in this investigation. Clinical status of each patient was evaluated before any treatment (initial score) at the end of perfusion and at the 24th hour. Efficiency of each treatment respectively was evaluated according to the differences between these three different scores. CHI 2 and U Mann's and Whitney's tests were utilized for the statistical analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗