-This paper describes for the first time a massive intoxication episode due to consumption of shellfish contaminated with 7-O-acyl-derivative dinophysistoxin-1, named Dinophysistoxin-3 (DTX-3). 7-O-acyl-derivative dinophysistoxin-1, a compound recently described in the literature, was found in shellfish samples collected in the Chilean Patagonia fjords. This compound does not inhibit Protein Phosphatases and also does not elicit the symptoms described for Diarrheic Shellfish Poisoning (DSP). The data showed here, give evidence of metabolic transformation of 7-O-acyl-derivative dinophysistoxin-1 (DTX-3) into Dinophysistoxin-1 (DTX-1, Methyl-Okadaic acid) in intoxicated patients. This metabolic transformation is responsible for the diarrheic symptoms and the intoxication syndrome showed by patients that consumed contaminated shellfish, which showed only the presence of 7-O-acyl-derivative dinophysistoxin-1. Patients fecal bacterial analysis for the presence of enteropathogens was negative and the mouse bioassay for DSP, performed as described for regulatory testing, was also negative.The HPLC-FLD and HPLC-MS analysis showed only the presence of DTX-3 as the only compound associated to DSP toxins in the contaminated shellfish samples. No other DSP toxins were found in the shellfish sample extracts. However, the patient fecal samples showed DTX-1 as the only DSP toxins detected in fecal. Moreover, the patient fecal samples did not show DTX-3.Since 7-O-acyl-derivative dinophysistoxin-1 (DTX-3) was the only compound associated to DSP toxins detected in the shellfish samples, an explanation for the diarrheic symptoms in the intoxicated patients would be the metabolic transformation of DTX-3 into DTX-1. This transformation should occur in the stomach of the poisoned patients after consuming 7-O-acyl-derivatives dinophysistoxin-1 (DTX-3) contaminated bivalves.

Neosaxitoxin showed an effective local anesthetic effect when injected in the subcutaneous plane. The efficacy of a 50-microg dose of neosaxitoxin was shown. This is the first report of neosaxitoxin as a local anesthetic in a human trial.

This study reports the data recorded from four patients intoxicated with shellfish during the summer 2002, after consuming ribbed mussels (Aulacomya ater) with paralytic shellfish toxin contents of 8,066 ± 61.37 µg/ 100 gr of tissue. Data associated with clinical variables and paralytic shellfish toxins analysis in plasma and urine of the intoxicated patients are shown. For this purpose, the evolution of respiratory frequency, arterial blood pressure and heart rate of the poisoned patients were followed and recorded. The clinical treatment to reach a clinically stable condition and return to normal physiological parameters was a combination of hydration with saline solution supplemented with Dobutamine (vasoactive drug), Furosemide (diuretic) and Ranitidine (inhibitor of acid secretion). The physiological condition of patients began to improve after four hours of clinical treatment, and a stable condition was reached between 12 to 24 hours. The HPLC-FLD analysis showed only the GTX3/GTX2 epimers in the blood and urine samples. Also, these epimers were the only paralytic shellfish toxins found in the shellfish extract sample.

Although, gonyautoxin anal fissures treatment recently published proved to be safe and effective, this study shows a better protocol for anal fissure treatment, showing better efficacy by shorting the healing time with better perception of healing by patients. Gonyautoxin anal sphincter infiltration proves to be safe and effective, reducing discomfort and healing time, advantageously comparing with alternative therapeutic approaches for chronic anal fissure.

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