scholarly journals Long Term Memory Outcome of Repetitive, Low-Level Dietary Exposure to Domoic Acid in Native Americans

Author(s):  
Lynn M. Grattan ◽  
Laura Kaddis ◽  
J. Kate Tracy ◽  
John Glenn Morris

Domoic acid (DA) is a marine-based neurotoxin that, if ingested via tainted shellfish, is associated with Amnesic Shellfish Poisoning (ASP). These acute effects of elevated DA exposure in humans have been well described. In contrast, the long-term impacts of lower level, repetitive, presumably safe doses of DA (less than 20 ppm) are minimally known. Since Native Americans (NA) residing in coastal communities of the Pacific NW United States are particularly vulnerable to DA exposure, this study focuses on the long-term, 8-year memory outcome associated with their repeated dietary consumption of the neurotoxin. Measures of razor clam consumption, memory, clerical speed and accuracy, and depression were administered over eight years to 500 randomly selected adult NA men and women ages 18–64. Data were analyzed using GEE analyses taking into consideration the year of study, demographic factors, and instrumentation in examining the association between dietary exposure and outcomes. Findings indicated a significant but small decline in total recall memory within the context of otherwise stable clerical speed and accuracy and depression scores. There is reason to believe that a continuum of memory difficulties may be associated with DA exposure, rather than a unitary ASP syndrome.

2020 ◽  
Vol 29 (4) ◽  
pp. 710-727
Author(s):  
Beula M. Magimairaj ◽  
Naveen K. Nagaraj ◽  
Alexander V. Sergeev ◽  
Natalie J. Benafield

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607


Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 458
Author(s):  
Juan Blanco ◽  
Carmen Mariño ◽  
Helena Martín ◽  
Gonzalo Álvarez ◽  
Araceli E. Rossignoli

Cultures of the mussel Mytilus galloprovincialis are frequently affected by accumulation of the amnesic shellfish poisoning toxin domoic acid (DA). This species is characterized by a fast uptake and release of the toxin. In this work, the main characteristics of the uptake mechanism have been studied by incubation of digestive gland thin slices in media with different composition and DA concentration. DA uptake seems to follow Michaelis–Menten kinetics, with a very high estimated KM (1722 µg DA mL−1) and a Vmax of 71.9 µg DA g−1 h−1, which is similar to those found for other amino acids in invertebrates. Replacement of NaCl from the incubation media by Cl-choline (Na+-free medium) did not significantly reduce the uptake, but replacement by sorbitol (Na+-free and Cl−-depleted medium) did. A new experiment replacing all chlorides with their equivalent gluconates (Na+- and Cl−-free medium) showed an important reduction in the uptake that should be attributed to the absence of chloride, pointing to a Na+-independent, Cl− (or anion-) dependent transporter. In media with Na+ and Cl−, neither decreasing the pH nor adding cyanide (a metabolic inhibitor) had significant effect on DA uptake, suggesting that the transport mechanism is not H+- or ATP-dependent. In a chloride depleted medium, lowering pH or adding CN increased the uptake, suggesting that other anions could, at least partially, substitute chloride.


2016 ◽  
Vol 5 (4) ◽  
Author(s):  
Rachele Rossi ◽  
Olga Arace ◽  
Maria Giovanna Buonomo ◽  
Daniela Capozzo ◽  
Vincenzo Castellano ◽  
...  

Algal biotoxins, chemical compounds produced by some microscopic algae, constitute the <em>phytoplankton</em>. The mussels, feeding on phytoplankton, can accumulate these compounds to become themselves toxic. There have been several cases of food poisoning by consumption of contaminated shellfish. Such food poisoning have pushed our health care system to provide monitoring of shellfish in the framework of the monitoring plans carried out by AASSLL. In this paper we report the results obtained monitoring the presence of ASP (Amnesic Shellfish Poisoning) biotoxins, like domoic acid (DA) and its isomers, produced by <em>Pseudonitzschia</em> algae. The analysis were carried out by using both the HPLC-UV official method and an experimental method performed with a Time of Flight mass spectrometer (ESI-TOF). The 100% of samples analysed by the official method have always been below the limits of sensitivity (except one sample), the 65% of samples analysed by ESI-TOF, showed the presence of domoic acid.


2011 ◽  
Vol 94 (2) ◽  
pp. 555-564 ◽  
Author(s):  
Pablo De La Iglesia ◽  
Esther Barber ◽  
Gemma Giménez ◽  
María Luisa Rodríguez-Velasco ◽  
Adriano Villar-González ◽  
...  

Abstract The application of ultra-performance rapid resolution LC on a 1.8 m particle-size column coupled with tandem MS (RRLC-MS/MS) is described for the analysis of amnesic shellfish poisoning (ASP) toxins in shellfish. Complete resolution among domoic acid (DA) and the isomers was achieved in less than 3 min. The method was intralaboratory validated for direct analysis of crude extracts without further cleanup. It showed LODs ranging from 0.05 to 0.09 mg/kg and a working range that complied with the current regulatory level for DA of 20 mg/kg, and with the level of 4.5 mg/kg recently proposed by the European Food Safety Authority. Confirmatory capabilities were demonstrated according to the Commission Decision 2002/657/EC criteria. The results obtained by RRLC-MS/MS agreed with those provided by the reference LC-UV method, both intralaboratory for the analysis of blind samples (R2 0.9751) and interlaboratory through participation in the proficiency test for ASP toxins during 2009 (z-score 0.962 and 0.177 for low- and high-contaminated samples, respectively). RRLC-MS/MS provided fast analysis and additional confirmatory capabilities for direct analysis of crude extracts while the performance and reliability of the results were maintained, even in very complex matrixes.


2000 ◽  
Vol 83 (6) ◽  
pp. 1384-1386 ◽  
Author(s):  
Kentaro Kawatsu ◽  
Yonekazu Hamano ◽  
Tamao Noguchi

Abstract Ten samples of commercial blue mussels (Mytilus edulis) from Japan were analyzed for domoic acid by an indirect competitive enzyme immunoassay (idc–EIA) based on an anti-domoic acid monoclonal antibody. Domoic acid was found in all samples at low concentrations (0.11–1.81 ng/g mussel tissue). The presence of domoic acid was confirmed by liquid chromatography coupled with immunoaffinity chromatography using an anti-domoic acid monoclonal antibody as ligand. To our knowledge, this is the first reported detection of domoic acid, a causative agent of amnesic shellfish poisoning, in Japanese mussels.


2001 ◽  
Vol 84 (5) ◽  
pp. 1657-1667 ◽  
Author(s):  
Philipp Hess ◽  
Susan Gallacher ◽  
Lesley A Bates ◽  
Nigel Brown ◽  
Michael A Quilliam

Abstract During 1998 and early 1999, shellfish samples from sites in Scotland were found to contain the amnesic shellfish poisoning toxin, domoic acid (DA). Two different techniques, liquid chromatography (LC) with UV diode-array detection and LC with mass spectrometric (MS) detection, were used to detect and confirm DA in shellfish extracts. The LC/UV method was validated for routine monitoring by recovery experiments on spiked mussel and scallop tissues with a certified mussel tissue used as reference material. Crude extracts of selected samples as well as extracts cleaned with strong anion exchange (SAX) were analyzed by both LC/UV and LC/MS. Good correlation (linear regression r2 = 0.996, slope = 0.93) between the 2 methods was found for cleaned extracts. Analyses of crude extracts by LC/UV produced false-positive results in 2 crab samples, whereas LC/MS analyses gave accurate results. It was concluded that LC/UV is a valid approach for routine monitoring of DA in shellfish when cleanup is performed with a SAX cartridge to prevent false positives. A variety of shellfish species were surveyed for DA content, including Pecten maximus (king scallops), Chlamys opercularis (queen scallop), Mytilus edulis (blue mussels), Cancer pugaris (crab), and Ensis ensis (razor fish). The highest concentration of DA was 105 μg/g in Pecten maximus.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Elena Barbaro ◽  
Roberta Zangrando ◽  
Carlo Barbante ◽  
Andrea Gambaro

Domoic acid (DA), a neurotoxic amino acid produced by diatoms, is the main cause of amnesic shellfish poisoning (ASP). In this work, we propose a very simple and fast analytical method to determine DA in mussel tissue. The method consists of two consecutive extractions and requires no purification steps, due to a reduction of the extraction of the interfering species and the application of very sensitive and selective HILIC-MS/MS method. The procedural method was validated through the estimation of trueness, extract yield, precision, detection, and quantification limits of analytical method. The sample preparation was also evaluated through qualitative and quantitative evaluations of the matrix effect. These evaluations were conducted both on the DA-free matrix spiked with known DA concentration and on the reference certified material (RCM). We developed a very selective LC-MS/MS method with a very low value of method detection limit (9 ng g−1) without cleanup steps.


2015 ◽  
Vol 98 (1) ◽  
pp. 82-84
Author(s):  
Gemma Giménez Papiol

Abstract Regulations aimed to protect public health from amnesic shellfish poisoning (ASP) are focused on the detection and accurate quantification of domoic acid(DA). The reference detection determination used by the different shellfish safety monitoring agencies worldwide is HPLC separation followed by UV detection, in which different chromatographic column lengths or brands are accepted as long as it is C18 column. A laboratory validation of this method showed different performance of two accepted chromatographic columns when analyzing Bolinus brandaris samples. A natural compound, present only in those samples that contained DA, was evidencedby one of the columns. The DA quantification obtained with the column that coelutes both compounds was approximately twice the amount obtained with the column that separates them. This difference has important consequences in the ASP toxins management for thisfishery. The identity and toxicity of the compound are still unknown.


2019 ◽  
Vol 37 (4) ◽  
pp. 407
Author(s):  
Daniel Freitas ◽  
George França ◽  
Thais Scherrer ◽  
Carlos Vilar ◽  
Raimundo Silva

AbstractIn the present paper, we analyze the signatures of long-range persistence in seismic sequences along Circum-Pacific subduction zones, from Chile to Kermadec, extracted from the National Earthquake Information Center (NEIC) catalog. This region, known as the Pacific Ring of Fire, is the world’s most active fault line, containing about 90% of the world’s earthquakes. We used the classical rescaled range (R/S) analysis to estimate the long-term persistence signals derived from a scaling parameter called the Hurst exponent, H. We measured the referred exponent and obtained values of H > 0.5, indicating that a long-term memory effect exists. We found a possible fractal relationship between H and the bs(q)-index, which emerges from the non-extensive Gutenberg-Richter law as a function of the asperity. Therefore, H can be associated with a mechanism that controls the level of seismic activity. Finally, we concluded that the dynamics associated with fragment-asperity interactions can be classified as a self-affine fractal phenomenon.Keywords: Applied geophysics; Fault and Fracture Analysis; Mathematics applied to geohysics; Seismology; Statistics;geostatistics ResumoNo presente artigo, analisamos as assinaturas de persistência long-range nas sequências sísmicas ao longo das zonas de subducção Circum-Pacific, do Chile até Kermadec, extraídas do catálogo do Centro Nacional de Informações sobre Terremotos (NEIC). Esta região, conhecida como Anel de Fogo do Pacífico, é a linha de falhas mais ativa do mundo, contendo cerca de 90% dos terremotos do mundo. Usamos a análise clássica R / S para estimar a assinatura de persistência a longo prazo derivada do parâmetro de escalonamento chamado expoente de Hurst, H. Como principal objeto de estudo}, medimos o referido expoente e obtivemos todos os valores de H> 0,5, indicando que existe um efeito de memória de longo prazo. A principal contribuição do nosso artigo foi encontrar uma possível relação entre H e o índice bs (q) - que emerge da lei de Gutenberg-Richter não-extensiva como uma função da aspereza, isto é, H pode estar associado ao mecanismo que controla o nível de atividade dos terremotos. Finalmente, concluímos que a dinâmica associada às interações fragilidade-aspereza pode ser classificado como um fenômeno fractal auto-afim.Palavras-chaves: Geofisica Aplicada; Analise de falhas e fraturas; Matematica Aplicada a Geofisica; Sismologia; Estatistica;geoestatistica


Author(s):  
Suriyanti Su Nyun Pau ◽  
Dzulhelmi Muhammad Nasir ◽  
Gires Usup

<p>Amnesic Shellfish Poisoning (ASP) is a type of intoxication caused by the neurotoxin domoic acid (DA). The diatom genus <em>Nitzschia</em> is capable of producing this toxin. Screening for the presence of toxic <em>Nitzschia</em> spp. was carried out at various estuaries in Malaysia. <em>Nitzschia</em>-like cells were isolated and established into clonal cultures. Late stationary phase of cultures were harvested and tested for toxin production using HPLC. Toxin production and compound was verified by LC-MS. From the analyses, at least three cultures were detected with DA, while the rest of the cultures did not show detectable amounts of DA. The localities of the toxic species are Johor and Sabah. Here we conclude that toxic <em>Nitzschia</em> species are present in Malaysian water.</p><p>Keywords: diatom, estuary, intoxication, safety, toxic </p>


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