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Abstract: Envenomation syndromes induced by Atlantic cnidaria have been tabulated and their therapy discussed. The pharmacokinetics of the venom has been emphasized. Pain occurs instantly and reaches a zenith rapidly in the surf. The nematocysts have already penetrated the dermis and disease proceeds before help can arrive. This fact plus the relative impermeability of human epidermis hampers the efficacy of topical agents. Oral analgesics, the agents of choice, are seldom offered and systemic administration of these drugs is usually not necessary. The use of hot or cold applications has not been settled. Measures to inactivate nematocysts within tentacles adherent to skin post-sting have been demonstrated in vitro, but the clinical significance of these actions has not been shown. Using an abrader (sand, crystalline papain) to counter-irritate nearby skin might provide relief. Antivenoms for Atlantic cnidaria are not available. The instances when verapamil might be employed are very rare. The reasons for the increasing case load of these injuries are discussed and the need to discover more effective therapeutic agents is emphasized. [Copyright &y& Elsevier]

Discusses the pathogenesis of jellyfish stings. Factors which influence the variability in adverse reactions produced by the stings; Importance of pharmakinetics of venom delivery to determine the organ site of damage and the extent of abnormality; Differences in allergic and toxic reactions caused in man by venom from the stings.

Reports on the investigation on the obstruction of jellyfish nematocysts by topical agents. Effects of topical application on the skin; Use of scanning electron to study nematocyst discharge on the human cadaver skin; Requirement of standard in vitro test to screen topical agents for protection of human skin.

A patient with phytophotodermatitis secondary to topical application of lime juice for relief of pain from a recent marine sting is reported. The absence of pain over the entire lesion and the failure of the patient to develop immune specific antibodies to common local coelenterates aided in establishing the diagnosis. [ABSTRACT FROM AUTHOR]

Abstract: A separation of toxic components from the upside down jellyfish Cassiopea xamachana (Cx) was carried out to study their cytotoxic effects and examine whether these effects are combined with a binding activity to cell membrane receptors. Nematocysts containing toxins were isolated from the autolysed tentacles, ruptured by sonication, and the crude venom (CxTX) was separated from the pellets by ultracentrifugation. For identifying its bioactive components, CxTX was fractionated by gel filtration chromatography into six fractions (named fraction I–VI). The toxicity of CxTX and fractions was tested on mice; however, the hemolytic activity was tested on saline washed human erythrocytes. The LD50 of CxTX was 0.75μg/g of mouse body and for fraction III, IV and VI were 0.28, 0.25 and 0.12μg/g, respectively. Fractions I, II and V were not lethal at doses equivalent to LD50 1μg/g. The hemolytic and phospholipase A2 (PLA2) activities of most fractions were well correlated with their mice toxicity. However, fraction VI, which contains the low molecular mass protein components (≤10kDa), has shown no PLA2 activity but highest toxicity to mice, highest hemolytic activity, and bound significantly to the acetylcholine muscarinic receptors (mAChRs) isolated from rat brain. The results suggested that fraction VI contains proteinaceous components contributing to most of cytolysis as well as membrane binding events. Meanwhile, fraction IV has shown high PLA2 that may contribute to the venom lethality and paralytic effects. [Copyright &y& Elsevier]