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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In Canada in late 1987 there was an outbreak of an acute illness characterized by gastrointestinal symptoms and unusual neurologic abnormalities among persons who had eaten cultivated mussels. Health departments in Canada solicited reports of this newly recognized illness. A case was defined as the occurrence of gastrointestinal symptoms within 24 hours or of neurologic symptoms within 48 hours of the ingestion of mussels. From the more than 250 reports received, 107 patients met the case definition. The most common symptoms were vomiting (in 76 percent of the patients), abdominal cramps (50 percent), diarrhea (42 percent), headache, often described as incapacitating (43 percent), and loss of short-term memory (25 percent). Nineteen patients were hospitalized, of whom 12 required intensive care because of seizures, coma, profuse respiratory secretions, or unstable blood pressure. Male sex and increasing age were associated independently with the risks of hospitalization and memory loss. Three patients died. Mussels associated with this illness were traced to cultivation beds in three river estuaries on the eastern coast of Prince Edward Island. Domoic acid, which can act as an excitatory neurotransmitter, was identified in mussels left uneaten by the patients and in mussels sampled from these estuaries. The source of the domoic acid appears to have been a form of marine vegetation, Nitzschia pungens, also identified in these waters in late 1987. The contaminated mussels from Prince Edward Island were removed from the market, and no new cases have occurred since December 1987. We conclude that the cause of this outbreak of a novel and severe intoxication was the ingestion of mussels contaminated by domoic acid, a potent excitatory neurotransmitter.
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PMID:An outbreak of toxic encephalopathy caused by eating mussels contaminated with domoic acid. 207 68

Toxins formed by organic micro-organisms may accumulate within certain tissues of predacious sea animals, which may serve as a source of seafood poisoning for the higher food chain. Such toxins are distinct from inorganic chemicals or infectious agents which may have contaminated the seafoods. Distinct clinical syndromes have emerged, and the individual toxins have been identified. Clinical manifestations of each begin with a gastrointestinal prodrome and headache, followed by sensorimotor deficits. Bulbar and cognitive changes are associated with the more lethal tetrodotoxin, saxitoxin, and domoic acid toxin. Tetrodotoxin and saxitoxin block sodium channels, while ciguatoxin opens them. Domoic acid stimulates excitatory amino acids at the NMDA receptors.
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PMID:Organic neurotoxins in seafoods. 765 83

Domoic acid is a shellfish toxin which produces gastrointestinal distress, followed by neurological symptoms such as headache, confusion, disorientation and severe deficits in short-term memory. Domoic acid is an amino acid which contains three carboxylic groups, and one imino group, and its solubility, rate of absorption, and elimination would vary depending on the protonation of these groups at different pH's. We propose that domoic acid toxicity varies with pH of administered domoic acid solution. Domoic acid toxicity was measured in mice as the onset times for scratching behaviour, seizure activity, and death, after the intraperitoneal administration of domoic acid at different pH's. Results of the present study show that the scratching behaviour, seizure activity, and death, occurred at 12, 40, and 55 min, after intraperitoneal administration of domoic acid at pH 3.7. Apparently, the onset times for three types of behaviours were relatively long, and well separated from each other. Domoic acid toxicity was lowest at pH 3.7, and highest at pH 7.4, with intermediate toxicity at other pH's. The onset time of scratching behaviour was not influenced by pH of domoic acid solution at three different doses. In contrast, the onset times for seizure activity, and death were significantly affected by pH of domoic acid, toxicity being higher at pH 7.4 than at pH 3.7. The pH effect on domoic acid toxicity diminished as the dose of domoic acid was increased. In fact, at 14.5 mg/kg domoic acid toxicity was similar at both pH's of 3.7 and 7.4. It is concluded that in vivo toxicity of domoic acid varies depending on pH of the administered solution. The differential toxicity of domoic acid at different pH may be related to its solubility, rate of absorption, and elimination, depending on the degree of protonation of domoic acid molecule. Domoic acid toxicity would also vary depending on the age of animal, receptor sensitivity and density in different regions of brain.
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PMID:Effect of pH on domoic acid toxicity in mice. 905 95