The researchers evaluated various types of liposomes containing saxitoxin
with or without dexamethasone, a potent steroid known to augment the action of encapsulated anesthetics.
After the initial 2002 saxitoxin
puffer fish poisoning (SPFP) events, 11 southern puffer fish were divided into the tissue compartments (listed above), and tissue samples were extracted by boiling in 0.1 N HCl (Washington Seafood Laboratory) and analyzed for toxic activity using three independent methods.
Detection and identification of a novel saxitoxin
analogue in Argentinean scallops (Zygochlamyspatagonica).
PSP primarily results from ingestion of saxitoxins
, toxins produced by marine dinoflagellate algae that accumulate in bivalve mollusks (e.g., butter clams, cockles, geoducks, and mussels) (1).
Cellular basis for saxitoxin
toxicity and chemical defense
Certified reference materials used were decarbamoylsaxitoxin (dcSTX), neosaxitoxin (NEO), saxitoxin
dihydrochloride (STX di-HCl), gonyautoxins 1-5 (GTX1-5), N-sulfocarbamoylgonyautoxin-2 and -3 (C1&2), decarbamoylneosaxitoxin (dcNEO), and decarbamoylgonyautoxin-2 and -3 (dcGTX2&3).
The largest and best known problem caused by harmful algal blooms (HAB) in Alaska is paralytic shellfish poisoning (PSP), which is caused by human ingestion of shellfish that have bioaccumulated a suite of toxins collectively known as paralytic shellfish toxins (PST), the most toxic of which is saxitoxin
(STX), produced by the dinoflagellate Alexandrium spp.
Testing of approximately 25 pufferfish collected from Florida waters by the Food and Drug Administration's (FDA) Center for Food Safety and Applied Nutrition (CFSAN), in collaboration with the Florida Fish and Wildlife Conservation Commission (FWC), and additional testing by FDA'S Northeast Regional Laboratory indicated that pufferfish containing potentially toxic concentrations of saxitoxins
(2-53 [mu]g saxitoxin
equivalent toxicity/g) are present in the Indian River in the area of the Titusville Pier.
However, the analysis confirmed that the fish contained the paralytic shellfish toxin, saxitoxin
, and two analogs, N-sulfocarbamoylsaxitoxin and decarbamoylsaxitoxin.
Specific toxicity Toxic content (fmol STX di-HCI Proportions of PST toxin (fmol/cell) equivalent/cell) PSP toxins (%) GTX4 0.6 0.4 1.2 GTX1 0.1 0.1 0.2 dcGTX3 + GTX5 0.4 0.1 0.4 GTX3 0.1 0.05 0.1 dcNeo + Neo 2.0 1.9 5.3 dcSTX 0.4 0.2 0.5 STX 0.2 0.2 0.4 C1 17.6 0.1 0.3 C2 332.1 32.0 91.5 Total 353 35 100 GTX, gonyautotoxins; dc, decarbamoyl; Neo, neosaxitoxin; STX, saxitoxin
; C1 and C2, C toxins.
Don Anderson, a senior scientist at Woods Hole, says harvesting closures typically occur only after toxins reach certain threshold concentrations, such as 80 micrograms of saxitoxin
per 100 grams of meat, or 20 micrograms of domoic acid per gram of meat.
Paralytic shellfish poisoning (PSP) is a foodborne illness caused by consumption of shellfish or broth from cooked shellfish that contain either concentrated saxitoxin
, an alkaloid neurotoxin, or related compounds.