Polyether toxins, detection

Hokama, Y., An enzyme immunoassay for the detection of ciguatoxin and competive inhibition by related natural polyether toxins, in Seafood Toxins, Ragelis, E., ed., American Chemical Society, Washington, D.C., 1984. 

In 1990, a solid-phase immunobead assay (SPIA), with colored polystyrene particles coated with anti-CTX monoclonal antibody (MAb-CTX) began to be used for direct detection of ciguatoxins adsorbed on bamboo paddles coated with organic correction fluid. The membrane immunob-ead assay (MIA) presented by in 1998 Hokama et al. is based on the immunological principles used to develop the SPIA, using a MAb-CTX coated onto colored polystyrene beads. The polyether toxins extracted from a piece of fish tissue bind to the hydrophobic membrane on a plastic support (membrane stick), and can be detected with the MAb-CTX coated onto the colored polystyrene beads. The color intensity of the membrane is related to the concentration of the toxin bound to the membrane. 

HPLC coupled to selective-ion monitoring ion spray mass spectrometry (ISMS) is an alternative to fluorescence detection of ciguatoxin in LC eluants, since ISMS is a sensitive method capable of the determination of the molecular weight of polyether toxins such as ciguatoxins, brevetoxins, and... 

Hokama, Y. et al., Simphfied solid-phase membrane immunobead assay (MIA) with monoclonal anti-ciguatoxin antibody (MAb-CTX) for detection of ciguatoxin and related polyether toxins, J. Nat. Toxins, 7, 1,1998. 

Hokama, Y. Shirai, L. K. Iwamoto, L. M. Kobayashi, M. N. Goto, C. S. Nakagawa, L. K. Assessment of a rapid enzyme immunoassay stick test for the detection of ciguatoxin and related polyether toxins in fish tissues. Biol. Bull. (Woods Hole, Mass.), 172 144-53. 1987. 

Immunological detection of ciguatoxins and related polyethers has received particular attention compared to other marine toxins. The initial RIA and enzyme immunoassay employing a polyclonal sheep anti-ciguatoxin antibody revealed cross-reactivities between ciguatoxins and other polyether toxins, suggesting the need for monoclonal antibodies. The availability of monoclonal antibodies allowed for the development of stick enzyme immrmoassay methods and solid-phase immunobead techniques (known as the paddle test), which successfully recognized toxins attached to correction fluid-coated bamboo sticks or paddles previously exposed to toxic fish tissues. 

Not all these polyether occur together in the same shellfish samples. OA was the major toxin in the mussel specimens from most of the European countries (42), while DTXl was the major toxin in mussel in Japan and in Sogndal, Norway (43). Scallops in Japan show the most complicated toxin profile. Furthermore, the relative ratio of the toxins varied regionally, seasonally, and annually. Pectenotoxins were detected, however, only in Japanese shellfish. Distribution of toxins is summarized in Table I. 

Methods of detection, metabolism, and pathophysiology of the brevetoxins, PbTx-2 and PbTx-3, are summarized. Infrared spectroscopy and innovative chromatographic techniques were examined as methods for detection and structural analysis. Toxicokinetic and metabolic studies for in vivo and in vitro systems demonstrated hepatic metabolism and biliary excretion. An in vivo model of brevetoxin intoxication was developed in conscious tethered rats. Intravenous administration of toxin resulted in a precipitous decrease in body temperature and respiratory rate, as well as signs suggesting central nervous system involvement. A polyclonal antiserum against the brevetoxin polyether backbone was prepared a radioimmunoassay was developed with a sub-nanogram detection limit. This antiserum, when administered prophylactically, protected rats against the toxic effects of brevetoxin. 

Hokama, Y. (1993). Recent methods for the detection of seafood toxins recent immunological methods for ciguatoxins and related polyethers. FoodAddit. Contam. 10, 71-82. 

Manger, R. L., Leja, L. S., Lee, S. Y. et al.. Detection of sodium channel toxins directed cytotoxicity assays of purified ciguatoxins, brevetoxins, saxitoxins, and seafood extracts, J. AOAC Int. 78, 521, 1995 Dechraoui, M. Y, Naar, J., PauUlac, S. et al., Ciguatoxins and brevetoxins, neurotoxic polyether compounds active on sodium chaimels, Toxicon 37, 125, 1999. 

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