Neurotoxicity poisoning

Lactone An organic compound that contains an ester group incorporated into a carbon ring structure. Lactones include the coumarins, e.g. umbelliferone or 7-hydroxycoumarin. Lactones and furocoumarins, e.g. bergaptene, exist in small quantities in essential oils and should be used with care. Lactones can be neurotoxic (poisonous to the nervous system) and cause skin allergies. Bergaptene is well known for its phototoxicity on the skin. 

Furey, A., Crowley, J., Hamilton, B., Lehane, M., and James, K. J. 2005. Strategies to avoid the mis-identification of anatoxin-a using mass spectrometry in the forensic investigation of acute neurotoxic poisoning. J Chromatogr A 1082, 91-97. 

FIGURE 69.3. In vitro protection of AChE from inhibition hy paraoxon or DFP by enzymatic hioscavengers (OPH or OPAA) and 2-PAM. The P50 value is the ratio at which 50% of a fixed concentration of AChE is protected from neurotoxic poisoning. From left to right, the kinetic curves are (1) OPH and paraoxon (2) OPH and DFP (3) OPAA and DFP (4) 2-PAM and paraoxon (5) 2-PAM and DFP (6) OPAA and paraoxon. 

See afeo Anxiolytics Neurotoxicity Poisoning Emergencies in Humans. 

Neurotoxic poisoning can result in five different categories of indicators. These and their symptoms are presented in Table 18.3. The material presented in Table 18.3 and the format has been adapted from the... 

Table 18.3 Indicators of Neurotoxic Poisoning and Their Symptoms11 4 231...

This chapter deals with single crystal x-ray diffraction as a tool to study marine natural product structures. A brief introduction to the technique is given, and the structure determination of PbTX-1 (brevetoxin A), the most potent of the neurotoxic shellfish poisons produced by Ptychodiscus brevis in the Gulf of Mexico, is presented as an example. The absolute configuration of the brevetoxins is established via the single crystal x-ray diffraction analysis of a chiral 1,2-dioxolane derivative of PbTX-2 (brevetoxin B). 

The toxicological consequences of P. brevis red tides are mass mortality of fishes exposed to the red tide toxic shellfish which, if consumed, result in human neurotoxic shellfish poisoning and an irritating aerosol which results from contact with P. brevis cell particles entrapped in seaspray. In all cases, the threshhold levels for intoxication are in the picomolar to nanomolar concentration ranges, implying a specific locus or loci of action for brevetoxins (reviewed in 6). 

Isoniazid Adults S mg/kg (300 mg) Children 1 0-1 S mg/kg (300 mg) Asymptomatic elevation of aminotransferases, clinical hepatitis, fatal hepatitis, peripheral neurotoxicity, CNS system effects, lupus-like syndrome, hypersensitivity, monoamine poisoning, diarrhea LFT monthly in patients who have preexisting liver disease or who develop abnormal liver function that does not require discontinuation of drug Dosage adjustments may be necessary in patients receiving anticonvulsants or warfarin... 

Some OP compounds induce delayed neurotoxic effects ("delayed neuropathy") after acute poisoning. This delayed neurotoxic action is independent of cholinesterase inhibition but related to phosphorylation of a specific esterasic enzyme in the nervous tissue, called "neurotoxic esterase" or "neuropathy target esterase" (NTE) (Johnson, 1982). NTE is present in the nervous tissue, liver lymphocytes, platelets, and other tissues, but its physiological function is unknown. There is a rather large inter-individual variation of lymphocyte and platelet NTE activity (Table 2). 

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