Domoic Acid Transfer to Milk: Evaluation of a Potential Route of Neonatal Exposure

Domoic acid (DA), produced by the diatom genus Pseudo-nitzschia, is a glutamate analog and a neurotoxin in humans. During diatom blooms, DA can contaminate filter-feeding organisms, such as shellfish, and can be transferred by ingestion to higher trophic levels. Several intoxication events involving both humans and various marine mammals have been attributed to DA. Affected organisms show neurological symptoms such as seizures, ataxia, headweaving, and stereotypic scratching, as well as prolonged deficits in memory and learning. Neonatal animals have been shown to be substantially more sensitive to DA than adults. However, it has not been demonstrated whether DA can be transferred to nursing young from DA-exposed mothers. This study demonstrates transfer of DA from spiked milk (0.3 and 1.0 mg/kg) to the plasma of nursing neonatal rats and an overall longer DA retention in milk than in plasma after 8 hr in exposed dams. DA was detectable in milk up to 24 hr after exposure (1.0 mg/kg) of the mothers, although the amount of DA transferred to milk after exposure was not sufficient to cause acute symptoms in neonates

Effects of increased pCO2 and temperature on the North Atlantic spring bloom. III. Dimethylsulfoniopropionate

The CLAW hypothesis argues that a negative feedback mechanism involving phytoplankton- derived dimethylsulfoniopropionate (DMSP) could mitigate increasing sea surface temperatures that result from global warming. DMSP is converted to the climatically active dimethylsulfide (DMS), which is transferred to the atmosphere and photochemically oxidized to sulfate aerosols, leading to increases in planetary albedo and cooling of the Earth’s atmosphere. A shipboard incubation experiment was conducted to investigate the effects of increased temperature and pCO2 on the algal community structure of the North Atlantic spring bloom and their subsequent impact on particulate and dissolved DMSP concentrations (DMSPp and DMSPd). Under ‘greenhouse’ conditions (elevated pCO2; 690 ppm) and elevated temperature (ambient + 4°C), coccolithophorid and pelagophyte abundances were significantly higher than under control conditions (390 ppm CO2 and ambient temperature). This shift in phytoplankton community structure also resulted in an increase in DMSPp concentrations and DMSPp:chl a ratios. There were also increases in DMSP-lyase activity and biomass-normalized DMSP-lyase activity under ‘greenhouse’ conditions. Concentrations of DMSPd decreased in the ‘greenhouse’ treatment relative to the control. This decline is thought to be partly due to changes in the microzooplankton community structure and decreased grazing pressure under ‘greenhouse’ conditions. The increases in DMSPp in the high temperature and greenhouse treatments support the CLAW hypothesis; the declines in DMSPd do not

Domoic Acid Transfer to Milk: Evaluation of a Potential Route of Neonatal Exposure-2

<p><b>Copyright information:</b></p><p>Taken from "Domoic Acid Transfer to Milk: Evaluation of a Potential Route of Neonatal Exposure"</p><p>Environmental Health Perspectives 2005;113(4):461-464.</p><p>Published online 20 Jan 2005</p><p>PMCID:PMC1278487.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p

Domoic Acid Transfer to Milk: Evaluation of a Potential Route of Neonatal Exposure-0

<p><b>Copyright information:</b></p><p>Taken from "Domoic Acid Transfer to Milk: Evaluation of a Potential Route of Neonatal Exposure"</p><p>Environmental Health Perspectives 2005;113(4):461-464.</p><p>Published online 20 Jan 2005</p><p>PMCID:PMC1278487.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p

Domoic Acid Transfer to Milk: Evaluation of a Potential Route of Neonatal Exposure-3

<p><b>Copyright information:</b></p><p>Taken from "Domoic Acid Transfer to Milk: Evaluation of a Potential Route of Neonatal Exposure"</p><p>Environmental Health Perspectives 2005;113(4):461-464.</p><p>Published online 20 Jan 2005</p><p>PMCID:PMC1278487.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p

Domoic Acid Transfer to Milk: Evaluation of a Potential Route of Neonatal Exposure-5

<p><b>Copyright information:</b></p><p>Taken from "Domoic Acid Transfer to Milk: Evaluation of a Potential Route of Neonatal Exposure"</p><p>Environmental Health Perspectives 2005;113(4):461-464.</p><p>Published online 20 Jan 2005</p><p>PMCID:PMC1278487.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p