Academic literature on the topic 'Domoic acid'

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Journal articles on the topic "Domoic acid"

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Eilers, P., S. Conrad, and S. Hall. "Domoic acid analysis." Toxicon 34, no. 3 (March 1996): 338. http://dx.doi.org/10.1016/0041-0101(96)81010-5.

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Wright, Jeffrey L. C., Michael Falk, A. Gavin McInnes, and John A. Walter. "Identification of isodomoic acid D and two new geometrical isomers of domoic acid in toxic mussels." Canadian Journal of Chemistry 68, no. 1 (January 1, 1990): 22–25. http://dx.doi.org/10.1139/v90-005.

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Isodomoic acids E and F, two new geometrical isomers of the neurotoxin domoic acid, have been found to occur with domoic acid and isodomoic acid D in extracts of toxic mussels. The entire set of geometrical isomers can be prepared in the laboratory by photolysis. Keywords: amnesic shellfish toxin, domoic acid, isodomoic acid, neurotoxin.
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Yao, Y., W. H. Nelson, P. Hargraves, and J. Zhang. "UV Resonance Raman Study of Domoic Acid, a Marine Neurotoxic Amino Acid." Applied Spectroscopy 51, no. 6 (June 1997): 785–91. http://dx.doi.org/10.1366/0003702971941296.

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Domoic acid, an amino acid neurotoxin, produces a single intense resonance Raman peak observed at 1652 cm−1 from aqueous solution when excited at either 242 or 257 nm. The detection limits for domoic acid in water are found to be well within those concentrations determined to be representative of values in toxic phytoplankton cells. Examination of cells known to contain identified large amounts of domoic acid shows that domoic acid spectra are sufficiently intensely excited to allow detection in the presence of normal phytoplankton cell constituents within the cell. Single cells from species established as producers of domoic acid, cultured under controlled conditions favorable to the production of domoic acid, produce spectra consistent with the presence of domoic acid in low concentrations.
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Ramsdell, John, and Frances Gulland. "Domoic Acid Epileptic Disease." Marine Drugs 12, no. 3 (March 6, 2014): 1185–207. http://dx.doi.org/10.3390/md12031185.

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Tasker, R. A. R., B. J. Connell, and S. M. Strain. "Pharmacology of systemically administered domoic acid in mice." Canadian Journal of Physiology and Pharmacology 69, no. 3 (March 1, 1991): 378–82. http://dx.doi.org/10.1139/y91-057.

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Domoic acid, a structural analogue of kainic acid, has been identified as the toxin that poisoned people who consumed contaminated blue mussels harvested from eastern Prince Edward Island in December of 1987. To investigate the pharmacology of domoic acid in vivo we injected groups of mice with serial dilutions of extracts of contaminated mussels and verified domoic acid concentrations using high performance liquid chromatography. Mice progressed through a series of behavioural changes that were both reproducible and dose-dependent. These behaviours formed the basis of a rating scale that was used to reliably quantitate domoic acid concentrations as low as 20 μg/mL. This scale was then used to compare the relative toxicity of domoic acid contained in four formulations: namely, (1) extracts of contaminated mussels, (2) pure domoic acid, (3) extracts of noncontaminated mussels that were "spiked" with pure domoate, and (4) extracts of the algal source of domoic acid. Interpolation of the resulting dose–response curves produced median toxic dose (TD50) values of 2.9, 3.9, 4.9, and 4.2 mg/kg for the four formulations, respectively. Statistical analysis of these data revealed that curves for all formulations of domoic acid were parallel, but that extracts of contaminated mussels were significantly more potent than any of the other formulations at low and intermediate doses of domoic acid. We further compared domoic acid toxicity with that produced by kainic acid. Dose–response curves for both compounds were statistically parallel and both toxins were equally efficacious. The TD50 values were 3.9 and 31.9 mg/kg for pure domoic acid and kainic acid, respectively. We conclude that this method can be effectively applied to studies of domoic acid pharmacology in vivo and that domoic acid is 8 – 11 times more potent than kainic acid following systemic administration.Key words: domoic acid, domoate, kainic acid, excitatory amino acid, amnesic shellfish poisoning.
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Mok, Jong-Soo, Ka-Jeong Lee, Ki-Cheol Song, and Ji-Hoe Kim. "Validation of the Analysis of Domoic Acid using High Performance Liquid Chromatography." Korean Journal of Fisheries and Aquatic Sciences 43, no. 4 (August 31, 2010): 293–97. http://dx.doi.org/10.5657/kfas.2010.43.4.293.

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Kawatsu, Kentaro, Yonekazu Hamano, and Tamao Noguchi. "Determination of Domoic Acid in Japanese Mussels by Enzyme Immunoassay." Journal of AOAC INTERNATIONAL 83, no. 6 (November 1, 2000): 1384–86. http://dx.doi.org/10.1093/jaoac/83.6.1384.

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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.
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Falk, Michael, John A. Walter, and Paul W. Wiseman. "Ultraviolet spectrum of domoic acid." Canadian Journal of Chemistry 67, no. 9 (September 1, 1989): 1421–25. http://dx.doi.org/10.1139/v89-218.

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The ultraviolet spectrum of aqueous domoic acid solutions has an intense absorption band, whose λmax shifts from 240.0 ± 0.3 nm at pH 1.3 to 244.7 ± 0.3 nm at pH 12.3. At the same time, its εmax increases from 24250 to 26700 L mol−1 cm−1. At pH 7 λmax is 242.8 ± 0.3 nm and εmax is 26035 ± 200 L mol−1 cm−1 Analysis of the variation of λmax and εmax with pH allowed us to estimate the values of these quantities for each of the five stages of protonation of domoic acid and to verify the pK values reported by Takemoto and Daigo. Keywords: ultraviolet spectrum, pK values, protonation, domoic acid.
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Johannessen, Jan N. "Stability of Domoic Acid in Saline Dosing Solutions." Journal of AOAC INTERNATIONAL 83, no. 2 (March 1, 2000): 411–12. http://dx.doi.org/10.1093/jaoac/83.2.411.

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Abstract Studies designed to assess the effects of repeated low doses of domoic acid require an assessment of its stability in solution under the conditions used for in vivo studies. The stability of 1 mg/mL solutions of domoic acid in saline, with or without ascorbic acid, was determined for 15 weeks. Solutions were refrigerated, but warmed to room temperature for several hours each working day to simulate conditions of actual use. The solutions of domoic acid showed no evidence of decomposition as evidenced by stability of UV absorbance spectrum, concentration of domoic acid as determined by a liquid chromatographic method, and the chromatographic elution pattern. The addition of ascorbate to the domoic acid/saline solution did not alter the stability, but was deemed unnecessary because of the firm stability of the domoic acid/saline solution.
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Wright, Jeffrey L. C. "Domoic acid - ten years after." Natural Toxins 6, no. 3-4 (May 1998): 91–92. http://dx.doi.org/10.1002/(sici)1522-7189(199805/08)6:3/4<91::aid-nt25>3.0.co;2-e.

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Dissertations / Theses on the topic "Domoic acid"

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Parekh, Punam K. "The Photooxidation of Domoic Acid." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/770.

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Domoic acid (DA) is a naturally occurring cyanotoxin, which upon ingestion, is responsible for amnesic shellfish poisoning (ASP) in both humans and animals. Produced by the marine diatom, Pseudonitzschia, DA is accumulated by a number of marine organisms including shellfish, clams and mussels which upon consumption can lead to headaches, nausea and seizures. Possessing a variety of functional groups the structure of DA contains three carboxyl groups, a pyrrole ring and a potent conjugated diene region allowing for binding to glutamate receptors in the dorsal hippocampus of the brain causing the described detrimental effects. Although limitations have been placed regarding the amount of DA that may be contained in seafood no limitations have been placed on the amount present in drinking water. Natural degradation of the toxin may occur through reactive oxygen species such as the hydroxyl radical and singlet oxygen at the conjugated diene region. In this work the photooxidation of DA via singlet oxygen has been studied using sorbic acid as a model compound. The three major reaction pathways observed during the photooxdiation process for both acids include 2 + 4 cycloaddition to produce endoperoxides , 2 + 2 reaction to afford aldehydes and ketones or an ene reaction to generate hydroperoxides. Under similar reaction conditions for SA and DA, the endoperoxide has been seen to be the major product for photoxidation of SA while the hydroperoxide has been seen to be the dominant product during photooxidation of DA.
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Fleary-Roberts, Nadia. "Towards the total synthesis of domoic acid and the isodomoic acids." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/towards-the-total-synthesis-of-domoic-acid-and-the-isodomoic-acids(a32fd085-8e09-47b5-b533-ef259b1ae8a2).html.

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Sedehizadeh, Simon. "Towards the total synthesis of domoic acid and the isodomoic acids." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/towards-the-total-synthesis-of-domoic-acid-and-the-isodomoic-acids(6a1a5ea8-f5a5-4185-8222-5d3486165ac9).html.

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Silvagni, Paul Anthony. "Comparative pathology and diagnosis of domoic acid toxicity /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.

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Lail, Erin M. "Biogeochemical cycling of domoic acid and its isomers in the ocean /." Electronic version (PDF), 2006. http://dl.uncw.edu/etd/2006/laile/erinlail.pdf.

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Knierim, Tika L. "The photodegradation of domoic acid and the effects of metal chelation /." Electronic version (PDF), 2005. http://dl.uncw.edu/etd/2005/knierimt/tikaknierim.html.

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Wittmaack, Christiana. "Behavioral Criteria for the Diagnosis of Domoic Acid Toxicosis in Zalophus californianus." NSUWorks, 2014. http://nsuworks.nova.edu/occ_stuetd/143.

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Introduction California sea lion (Zalophus californianus) health is severely compromised by domoic acid toxicosis, which occurs in high levels during harmful algal blooms of Pseudonitzschia australis along the coast of California. Current diagnostic protocols are often inconclusive due to a 2-48 hour window of detectability within the urinary, circulatory, and gastric systems (Cook, et al. 2011 and Monte, Pers Comm, 2012). Past studies suggest that Z. californianus, with domoic acid toxicosis, commonly display abnormal behaviors (Goldstein, et al. 2008). However, many of these abnormal behaviors are also associated with other diagnoses and are therefore unreliable as diagnostic indicators. This study fills in a knowledge gap relating to abnormal behavior types and their correlation to domoic acid toxicosis and helps solve the problem of current, inconclusive, diagnostic protocols. In this study, my objectives were to identify abnormal behaviors correlated to domoic acid toxicosis, create a diagnostic ethogram, determine the applicability of the method in the field, and determine the applicability of triage based on the relationship between abnormal behaviors and domoic acid levels. Methods I conducted focal animal continuous scans (continuous observation of a single animal at a time, for a set period) with continuous data entry, on animals admitted to the Marine Mammal Center (main study location during 2011-2013) and the Marine Mammal Care Center (comparison location, 2013). I conducted my observations from behind a blind to prevent both human habituation and behavioral influence of the observer. Observations lasted between 10-15 minutes (10 minutes per pen in 2011, 15 minutes per animal in 2012-2013). Subjects were selected based on an admit date no later than 7 days from the observation date. I conducted focal animal continuous scans at Pier 39, a haul out location, in the San Francisco Bay. Animals included in the study had identifying marks or were isolated from other animals (making them easy to identify). I observed animals once per observation day with a total observation period not exceeding 15 minutes per animal. I logged domoic acid levels in feces, urine, and serum (collected by veterinary staff and analyzed with liquid chromatography and bioassays for the presence of domoic acid). I then compared these results to the types and severity of abnormal behaviors displayed by the domoic acid toxicosis sample. Results Results from data collected at the Marine Mammal Center suggest that head weaving (Wilcoxon, p Results from the Pier 39 study suggest that behavioral criteria may be applicable for ruling out domoic acid toxicosis in groups of animals. However, I did not test the method during times of harmful algal blooms. Therefore, the applicability of the method for use as a diagnostic tool in the field is unknown and further research is required. Results for the triage study were inconclusive. The number of animals that tested positive for domoic acid was small and not suitable for statistical analysis. I suggest further research into triage abilities. Conclusion Based on the results of these studies, I can conclude that behavioral analysis offers a reliable diagnostic tool for rescued Z. californianus. Practitioners can use behavioral diagnostic criteria with confidence for the diagnosis of domoic acid toxicosis in Z. californianus.
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Vranyac-Tramoundanas, Alexandra, and n/a. "Domoic acid-induced cardiac damage : an in vitro and in vivo investigation." University of Otago. Department of Pharmacology & Toxicology, 2007. http://adt.otago.ac.nz./public/adt-NZDU20071012.143651.

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Cardiovascular pathology is seen in both animals and humans after domoic acid intoxication. Whether this damage is direct (i.e., cardiotoxic) or indirect (i.e., CNS/autonomic seizures) is not known. We have previously shown that acute in vitro domoic acid (0.05-0.25[mu]M; 10 min) treatment of isolated cardiac mitochondria compromises mitochondrial FADH and NAD⁺-linked respiratory control and mitochondrial energetics. Domoic acid was shown to traverse and bind the cellular membrane of H9c2 cardiac myoblasts. However it did not compromise cellular viability as assessed using cell quantification or lactate dehydrogenase leakage assays. Exposure of intact H9c2 cells to domoic acid only resulted in complex II-III activity impairment and assessment of reactive oxygen species (superoxide and hydrogen peroxide) production in both isolated cardiac mitochondria and H9c2 cardiomyocytes failed to show any significant differences following exposure to domoic acid. Acute ex vivo domoic acid treatment of an isolated myocardium in Langendorff perfusion mode failed to result in cardiac haemodynamic dysfunction, however there appeared to be small but significant decrease in mitochondrial oxygen utilization. The absence of any substantial damage to intact cardiomyocytes and isolated myocardium suggested that domoic acid does not have a direct toxicological effect on cardiac energetics. We therefore investigated the possibility that cardiovascular pathology is an indirect consequence of autonomic seizure activity. Domoic acid was administered intraperitoneally or intrahippocampally and the development of cardiac pathologies was assessed and compared. Sprague-Dawley rats receiving either i.p. or i.h. domoic acid were assessed behaviourally and shown to reach similar levels in their cumulative seizure scores. Assessment of the cardiac haemodynamics (LVDP, dP/dt, heart rate and coronary flow) revealed a significant time-dependent decrease in function at 1, 3, 7 & 14-days post-i.p. and 7 & 14-days post-i.h. domoic acid administration. Measurement of ventricular mitochondrial oxygen utilization revealed a similar time-dependent decrease in respiratory control, which appeared to be associated with increased proton leakage, shown by an increase in state-4 respiration rate (P<0.01). Assessment of the mitochondrial electron transport chain (complexes I-V) and the mitochondrial marker of integrity, citrate synthase, showed marked time-dependent impairment in both models of domoic acid -induced seizures. Oxidative stress did play a small role in the myocardial damage as indicated by the small decrease in aconitase activity (P<0.05). Plasma IL-1α, IL-1β and TNF-α levels were significantly increased from 3-days post seizures. Haematoxylin & Eosin staining of ventricular sections revealed the formation of contraction bands, inflammation and oedema, confirming a structural pathology. Cardiac damage did not differ between i.p. and i.h. animals, suggesting cardiac damage following domoic acid results from CNS autonomic seizures and resultant sympathetic storm. This thesis has demonstrated, for the first time, that the cardiac pathology seen following domoic acid exposure is most likely to be a result of CNS activation and resultant seizure episodes, and is not a consequence of the direct interaction between domoic acid and the myocardium. We have also demonstrated for the first time, that seizure episodes result in chronic cardiac dysfunction and a structural pathology which is similar, but not identical to that seen following isoprotenerol administration in vivo.
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Hesp, Blair, and n/a. "In vitro and In vivo investigations of tolerance induction and the role of G-protein coupled kainate receptors." University of Otago. Department of Pharmacology & Toxicology, 2005. http://adt.otago.ac.nz./public/adt-NZDU20070503.150053.

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The excitotoxin domoic acid (DOM) acts at both kainic acid (KA)- and α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)-sensitive glutamate receptors. Clinical reports suggest that elderly people are hypersensitive to the neurological effects of DOM intoxication. Young, but not aged hippocampal slices which have been preconditioned with low concentrations of DOM or KA exhibit an acute �tolerance� to subsequent high doses of DOM or KA; application of the selective AMPA agonist fluorowillardiine (FW) fails to induce tolerance to excitotoxins. The aim of this study was to further investigate the molecular mechanism of tolerance induction in vitro, and to examine the ability of compounds to cross-condition against excitotoxic insult. In addition, in vivo techniques were used to explore the age-related susceptibility to the neurological effects of DOM and acute in vivo tolerance induction. Here we show that low doses of �classical� ionotropic kainate receptor agonists and AMPA/kainate receptor antagonists act as net inverse agonists at G-protein coupled receptors, reducing constitutive GTPase activity by up to 73% in the young hippocampus. Further evidence that inverse agonist activity at G-protein coupled receptors is responsible for acute in vitro tolerance induction by kainate receptor agonists and antagonists was also identified because preconditioning with the AMPA receptor antagonist GYKI-52466 significantly inhibited KA-induced population spike suppression in in vitro hippocampal brain slices from both Sprague-Dawley and Wistar rats. The broad-spectrum protein kinase inhibitor H-7 partially blocked tolerance induction when preconditioning occurs in the presence of suggesting that protein kinases are one of the downstream effectors of this phenomenon. Tolerance-inducing compounds are also capable of cross-conditioning against the effects of other excitotoxins; with 250 nM FW suppressed population spike area by only 62.8 � 10.0% at 30 minutes following a 500 nM KA preconditioning dose, compared to almost complete spike suppression within twenty minutes in naive hippocampal brain slices. In vivo experiments indicated that despite aged animals exhibiting significantly higher cumulative behavioural scores in response to i.p. DOM (1 mg kg⁻�; young = 102 � 9, aged = 179 � 19; P < 0.01) in response to DOM after two hours), and that this age-related supersensitivity is due to impaired renal clearance (young serum DOM = 41.5 � 30.3 ng ml⁻�, aged = 813.3 � 804.4 ng ml⁻� following administration of 1 mg kg⁻� DOM after 2.5 hours earlier). Tolerance to high doses of DOM was induced within a matter of minutes following i.p. preconditioning by low dose DOM in vivo. This was evidenced by severe seizure manifestations being almost absent in both young and aged animals, despite occurring frequently in naive animals. Therefore, this study concludes that tolerance is induced by kainate receptor ligands in vitro and in vivo within a matter of minutes, and is the result of a reduction in the turnover of G-protein coupled receptors and protein kinase activation. In addition, the increased sensitivity of aged rats to in vivo DOM is a result of elevated serum DOM concentrations most likely resulting from impaired renal clearance.
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Fehling, Johanna. "Diversity, ecology and domoic acid production of Pseudo-nitzschia spp. in Scottish waters." Thesis, Open University, 2004. https://pure.uhi.ac.uk/portal/en/studentthesis/diversity-ecology-and-domoic-acid-production-of-pseudonitzschia-spp-in-scottish-waters(4b83d442-d9f6-4b9b-bc2f-666623b42d0b).html.

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Some diatoms of the genus Pseudo-nitzschia produce the toxin domoic acid (DA). Accumulation of DA in shellfish has led to harvesting closures in western Scottish waters since 1999. This thesis investigated the diversity, ecology and distribution of toxic and non-toxic Pseudo-nitzschia species in western Scottish waters and physiological aspects of growth and toxin production dynamics of P. seriata. The temporal and spatial distribution of phytoplankton was analysed in two separate field studies. 1) Temporal changes were followed by sampling a site in coastal Scottish waters weekly to fortnightly over a period of three years. 2) The spatial distribution of the phytoplankton community was investigated by sampling a transect across-the shelf. Within both studies, physical, biological and chemical parameters were measured and correlated to temporal and spatial distribution patterns in the phytoplankton community, indicating seasonality, and differences in the distribution of toxic and non-toxic Pseudo-nitzschia species between coastal and offshore waters. From those samplings 59 clonal cultures of Pseudo-nitzschia, comprising 7 species (2 of them toxic), were established. Strains were identified via classic morphological and genetic techniques. Phylogenetic relationships were established between Scottish Pseudo-nitzschia strains. P. seriata was identified for the first time in Scottish waters as a DA producer. Laboratory experiments with cultured strains showed a) enhanced toxin production by P. seriata under silicate (Si) and phosphate (P) limitation, with higher DA production under Si than under P limitation b) similar cell yields of P. seriata, when grown in nitrate or ammonia based media c) a preference for spring light conditions (short day length) in a non-toxic P. delicatissima strain and summer light conditions (long day length) for a toxic P. seriata strain, expressed by enhanced biomass yield under the respective light condition. It was also shown that the presence of bacteria enhanced the growth of single P. seriata cells.
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Books on the topic "Domoic acid"

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Health and Welfare Canada. Canada Diseases Weekly Report. Proceedings of a symposium: Domoic Acid toxicity. Ottawa: Health and Welfare Canada., 1990.

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I, Hynie, and Canada. Health and Welfare Canada., eds. Domoic acid toxicity: Proceedings of a symposium. Ottawa: Dept. of National Health and Welfare, 1989.

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Blanchard, John Robert. Pharmacokinetics of Domoic acid following intravenous administration in rats. Ottawa: National Library of Canada, 1990.

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Blanchard, John Robert. Pharmacokinetics of Domoic acid following intravenous administration in rats. Charlottetown: University of Prince Edward Island, 1990.

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Brown, Jennifer Ann. Effects of kainic and domoic acids on the release of glutamate and aspartate from the rat brain synsptosomes. Ottawa: National Library, 1992.

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Brown, Jennifer Ann. Effects of kainic and domoic acids on the release of glutamate and aspartate from rat brain synaptosomes. Charlottetown: University of Prince Edward Island, 1992.

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Osis, Vicki. Domoic acid and amnesiac shellfish poisoning: By Vicki Osis. [Corvallis, Or.]: Oregon Sea Grant, Oregon State University, 2003.

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1951-, Wood Anne Michelle, Shapiro Lynda M, Oregon State University. Sea Grant College Program., Oregon Institute of Marine Biology., and United States. National Oceanic and Atmospheric Administration., eds. Domoic acid: Final report of the workshop, Oregon Institute of Marine Biology, February 21-23, 1992. 2nd ed. Corvallis, Or: Oregon Sea Grant, Oregon State University, 1994.

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1951-, Wood Anne Michelle, Shapiro Lynda M, Oregon State University. Sea Grant College Program., Oregon Institute of Marine Biology., and United States. National Oceanic and Atmospheric Administration., eds. Domoic acid: Final report of the workshop, Oregon Institute of Marine Biology, February 21-23, 1992. Corvallis, Or: Oregon Sea Grant, Oregon State University, 1993.

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I, Hynie, Todd, E. C. D. 1939-, Canada Food Directorate, and Laboratory Centre for Disease Control (Canada), eds. Domoic acid toxicity: Proceedings of a symposium, Ottawa, Ontario 11-12 April 1989. [Ottawa]: Health and Welfare, Canada, 1990.

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Book chapters on the topic "Domoic acid"

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La Barre, Stéphane, Stephen S. Bates, and Michael A. Quilliam. "Domoic Acid." In Outstanding Marine Molecules, 189–216. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527681501.ch08.

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Cortinovis, Cristina, Leon J. Spicer, Maria Chiara Perego, Teresa Coccini, and Francesca Caloni. "Domoic Acid." In Handbook of Foodborne Diseases, 1031–36. Boca Raton : Taylor & Francis, [2019] | Series: Food microbiology series | “A CRC title, part of the Taylor & Francis imprint, a member of the Taylor & Francis Group, the academic division of T&F Informa plc.”: CRC Press, 2018. http://dx.doi.org/10.1201/b22030-96.

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Pérez-Gómez, Anabel, and R. Andrew Tasker. "Domoic Acid As a Neurotoxin." In Handbook of Neurotoxicity, 1–25. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-71519-9_87-1.

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Pérez-Gómez, Anabel, and R. Andrew Tasker. "Domoic Acid as a Neurotoxin." In Handbook of Neurotoxicity, 399–419. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4614-5836-4_87.

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Pérez-Gómez, Anabel, and R. Andrew Tasker. "Domoic Acid as a Neurotoxin." In Handbook of Neurotoxicity, 873–97. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15080-7_87.

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Doucette, Tracy A., and R. Andrew Tasker. "Perinatal Domoic Acid as a Neuroteratogen." In Neurotoxin Modeling of Brain Disorders—Life-long Outcomes in Behavioral Teratology, 87–110. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/7854_2015_417.

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Tasker, R. Andrew. "Domoic Acid and Other Amnesic Toxins: Toxicological Profile." In Marine and Freshwater Toxins, 93–112. Dordrecht: Springer Netherlands, 2016. http://dx.doi.org/10.1007/978-94-007-6419-4_21.

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Tasker, R. Andrew. "Domoic Acid and Other Amnesic Toxins: Toxicological Profile." In Marine and Freshwater Toxins, 1–16. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-007-6650-1_21-1.

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Villac, M. C., D. L. Roelke, T. A. Villareal, and G. A. Fryxell. "Comparison of two domoic acid-producing diatoms: a review." In Twelfth International Diatom Symposium, 213–24. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-017-3622-0_23.

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Syaifudin, A. R. Mohd, K. P. Jayasundera, and S. C. Mukhopadhyay. "Novel Planar Interdigital Sensors for Detection of Domoic Acid in Seafood." In Lecture Notes in Electrical Engineering, 253–78. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-17943-3_13.

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Conference papers on the topic "Domoic acid"

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Lee, Hoyong, Hayeon Park, and Chang–Gun Lee. "Adaptive Frequency Cluster-Level Performance Profiler for Multi-Domain Applications." In 2024 IEEE/ACIS 22nd International Conference on Software Engineering Research, Management and Applications (SERA), 35–42. IEEE, 2024. http://dx.doi.org/10.1109/sera61261.2024.10685562.

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Hendrickson, O. D., E. A. Zvereva, A. V. Zherdev, and B. B. Dzantiev. "IMMUNOCHROMATOGRAPHIC TEST SYSTEM FOR SIMULTANEOUS DETECTION OF PHYCOTOXINS MICROCYSTIN-LR AND DOMOIC ACID." In NOVEL TECHNOLOGIES IN MEDICINE, BIOLOGY, PHARMACOLOGY AND ECOLOGY. Institute of information technology, 2022. http://dx.doi.org/10.47501/978-5-6044060-2-1.52-57.

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An immunochromatographic test system has been developed for the simultaneous detection of two phycotoxins, domoic acid (DA) and microcystin-LR (MC-LR). The assay is implemented in an indirect competitive format using anti-species antibodies labeled with colloidal gold nanoparticles. The instrumental/visual detection limits are 2/80 and 0.05/0.3 ng/mL for DA and MS-LR, respectively; the assay duration is 18 min. The applicability of the developed test system for the determination of phycotoxins in seawater is shown. This work was supported by the Russian Science Foundation (project no. 20-43-07001).
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Hendrickson, O. D., O. N. Solopova, E. A. Zvereva, A. V. Zherdev, P. G. Sveshnikov, and B. B. Dzantiev. "Lateral flow immune sensor for phycotoxin domoic acid: New reactants for sensitive detection." In PROCEEDINGS OF THE 11TH INTERNATIONAL ADVANCES IN APPLIED PHYSICS AND MATERIALS SCIENCE CONGRESS & EXHIBITION. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0144455.

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Falk, Michael. "The Role Of FT-IR In The Identification Of Domoic Acid, A New Shellfish Toxin." In Intl Conf on Fourier and Computerized Infrared Spectroscopy, edited by David G. Cameron. SPIE, 1989. http://dx.doi.org/10.1117/12.969641.

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O'Connell, Eoin, William B. Lyons, Cormac Sheridan, and Elfed Lewis. "Development of a fibre optic sensor for the detection of harmful algae bloom and in particular domoic acid." In 2007 IEEE Instrumentation & Measurement Technology Conference IMTC 2007. IEEE, 2007. http://dx.doi.org/10.1109/imtc.2007.379024.

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Morgenroth, J., A. Harrell, and K. Neller. "Assessing the potential for chronic exposure to low levels of domoic acid through the use of Solid Phase Adsorption Toxin Tracking." In OCEANS 2012. IEEE, 2012. http://dx.doi.org/10.1109/oceans.2012.6404802.

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Jenny, Richard J., Debra D. Pittman, John J. Toole, Ronald W. Kriz, Randal J. Kaufman, and Kenneth G. Mann. "THE COMPLETE AMINO ACID SEQUENCE OF HUMAN FACTOR V." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643887.

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cDNA clones encoding human factor V have been isolated and sequenced. The cDNA sequence of factor V obtained from overlapping clones includes a 6672 bp coding region, a 90 bp 5'-untranslated region and a 163 bp 3’-untranslated region including a poly-A tail. The deduced amino acid sequence consists of 2224 amino acids including a 28 amino acid leader peptide. A direct comparison to human factor VIII reveals considerable homology between both proteins with respect to amino acid sequence and domain structure. A triplicated "A" domain and duplicated "C" domain show an approximate 40% identity to the corresponding domains in factor VIII. Factor V and Factor VIII both possess a heavily glycosylated B domain that separates the heavy and light chains of the activated cofactors, although no significant homology is observed in this region. The B domain of factor V contains 35 tandem and approximately 9 additional semi - conserved repeats of nine amino acids of the form (D-L-S-Q-T-T-L-S-P) and 2 additional semi-conserved repeats of 17 amino acids. Factor V contains 37 potential N-linked glycosylation sites, 25 of which are in the B domain, and a total of 19 cysteine residues. By direct comparison to amino acid sequence obtained from both human and bovine factor V, the thrombin (IIa) cleavage sites have been assigned as Arg-709/Ser-710, Arg-1018/Thr-1019, and Are-1545/Ser-1546.(Supported by NIH Grant HL-34575)
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Stenflo, J., A.-K. öhlin, Å. Lundvall, and B. Dahlback. "β-HYDROXY ASPARTIC ACID AND ft-HYDROXYASPARAGINE IN THEEGF-HOMOLOGY REGIONS OF PROTEIN C AND PROTEINS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643995.

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The amino acid sequence has been determined for all of the vitamin K-dependent proteins and the gene structure is known for some of them. These findings have shown the proteins to consist of four clearly discernible domains, except protein S which has six domains. The protein domains seem to be coded on separate exons (Foster, D. C. et. al. 1985 Proc. Natl. Acad. Sci. USA 82,4673). The vitamin K-dependent γ-carboxyglutamic acid (Gla) containing domain isthe common structural denominator of the members of this protein family. In addition, all of these proteins except prothrombin contain domains that are homologous to the precursor of the epidermal growth factor (EGF). Such domains arealso found in proteins that are not vitamin K-dependent, such as the low density lipoprotein receptor, thrombomodulin, factor XII, plasminogen, the tissue type plasminogen activator, urokinase and the complement protein Clr. The vitamin K-dependent proteins can be dividedinto three groups. Factors VII, IX, X, protein C and protein Z form one group, which in addition to the Gla-region have two EGF-homology regions and one domain that is homologous to the serine proteases. Prothrombin has two 'kringle' structures and a serine protease domain and constitutes a group of its own. Protein S is also unique in that it has four EGF-homology regions and a COOH-terminal region that is homologous to the sexual hormone binding globulin (see poster by Edenbrand et. al.).Recently a posttranslationally modified amino acid, B-hydroxyaspatic acid (Hya), was identified in position 71 in the NH2-terminal EGF-homology region ofbovine protein C. The amino acid is formed by hydroxylation of aspartic acid. It has also been identified in the corresponding positions in factors VII, IX,X and protein Z (i. e. proteins which like protein C have two EGF-homology regions each). In protein S the N2-terminal of four EGF-homology regions has hydroxy lated aspartic acid .whereas the following three EGF-like domains have B-hydroxyasparagine. The nucleotide sequence codes for asparagine in the three latter positions. Neither vitamin K nor vitamin C seem to be involvedin the formation of the two hydroxylated amino acids. Recently, Hya was identified in acid hydrolysates of the complement protein Clr. Hya and Hyn have onlybeen found in domains that are homologous to the EGF precursor. In an attempt to identify the structural requirement of the hydroxylating enzyme, we have compared the sequences of EGF-homology regions that contain Hya or Hyn with the corresponding sequences that have been shown not to contain the modified amino acids. The domains that have Hya or Hyn have the consensus sequence Cx xxxx xCxC. This sequence has been found in three EGF-like domains in the EGF-precursor, in two in the LDL-receptor and in two in thrombomodulin. Furthermore, the neurogenic Notch locus in Drosophila melanogaster codes for 36 EGF-homolgy regions, 22 of which contain the consensussequence, whereas the Lin-12 locus in Caenorhabditis elegans codes for at least 11 EGF-like repeats, two of which comply with the consensus sequence. Whether any of these proteins contain Hya orHyn is not yet known with certainty.It has been hypothesized that Hya isinvolved in the Gla independent Ca2+binding of factors IX, X and protein C. In an attempt to resolve this issue, we have isolated the EGF-homology region from human protein C and been able to demonstrate that it binds Ca2+ (see poster by öhlin and Stenflo). However, we do not yet know whether Hya is directly involved in the Ca2+binding.
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Kaufman, Randal J., Debra D. Pittman, Louise C. Wasley, W. Barry Foster, Godfrey W. Amphlett, and Alan R. Giles. "DIRECTED MUTAGENESIS IN THE STUDY OF THE REQUIREMENTS FOR FACTOR VIII ACTIVITY IN VITRO AND IN VIVO." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644769.

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Factor VIII is a high molecular weight plasma glycoprotein that functions in the blood clotting cascade as the cofactor for factor DCa proteolytic activation of factor X. Factor VIII does not function proteolytically in this reaction hut itself can be proteolytically activated by other coagulation enzymes such as factor Xa and thrombin. In the plasma, factor VIII exists as a 200 kDa amino-terminal fragment in a metal ion stabilized complex with a 76 kDa carboxy-terminal fragment. The isolation of the cENA for human factor VIII provided the deduced primary amino acid sequence of factor VIIT and revealed three distinct structural domains: 1) a triplicated A domain of 330 amino acids which has homology to ceruloplasmin, a plasma copper binding protein, 2) a duplicated C domain of 150 amino acids, and 3) a unique B domain of 980 amino acids. These domains are arranged as shown below. We have previously reported the B domain is dispensible far cofactor activity in vitro (Toole et al. 1986 Proc. Natl. Acad 5939). The in vivo efficacy of factor VIII molecules harboring the B domain deletion was tested by purification of the wildtype and modified forms and infusion into factor VIII deficient, hemophilic, dogs. The wildtype and the deleted forms of recombinant derived factor VIII exhibited very similar survival curves (Tl/2 = 13 hrs) and the cuticle bleeding times suggested that both preparations appeared functionally equivalent. Sepharose 4B chromatography indicated that both factor VIII molecules were capable of binding canine plasma vWF.Further studies have addressed what cleavages are necessary for activation of factor VIII. The position of the thrombin, factor Xa, and activated protein C (AFC) cleavage sites within factor VIII are presented below, site-directed ENA medicated mutagenesis has been performed to modify the arginine at the amino side of each cleavagesite to an soleucine. In all cases this modification resulted in molecules that were resistant to cleavage by thrombin at the modified site. Modification of the thrombin cleavage sites at 336 and 740 and modification of the factor Xa cleavage site at 1721 resulted in no loss of cofactor activity. Modification of the thrombin cleavage site at either 372 or 1689 destroyed oofactor activity. Modification of the thrombin cleavage site at 336 resulted in a factor VIII having an increased activity, possibly due to resistance to inactivation. These results suggest the requirement of cleavage at residues 372 and 1689 for cofactor activity.
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Butler-Zimrin, A. E., J. S. Bennett, M. Poncz, E. Schwartz, S. Surrey, R. Eisman, R. A. Heidenreich, and G. Vilaire. "ISOLATION AND CHARACTERIZATION OF cDNA CLONES FOR THE PLATELET MEMBRANE GLYCOPROTEINS IIb and IIIa." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643961.

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The platelet membrane GPIIb/GPIIIa complex on activated platelets contains receptors for fibrinogen, von Willebrand factor, and fibronectin. GPIIb and GPIlia also appear to be members of a family of membrane receptors involved in cell-cell and cell-matrix interactions. To study the structure of GPIIb and GPIIIa, we have constructed an expression library in the vector lambda gtll using mRNA from the HEL cell line and screened it with polyclonal antibody against each platelet protein. HEL cells constitutively express proteins similar to platelet GPIIb and GPIIIa. A 3.2kb GPIIb cDNA clone was identified that encodes for all 1008 amino acids of GPIIb including the known N-terminal amino acids of the α Cand βsubunits. This confirms that GPIIb is synthesized as a single chain polypeptide that is cleaved into two disulfide-linked subunits posttranslation. Analysis of the amino acid sequence revealed a major C-terminal transmembrane domain in the βsubunit, two potential transmembrane domains near the N-terminus of the αsubunit, and four possible N-linked glycosylation sites. Approximately 30% amino acid identity was found between GPIIb and the available amino acid sequences for the larger chains of the fibronectin and vitronectin receptors. Initial sequence analysis of a 3.8kb cDNA for GPIIIa included the known N-terminal amino acids of the platelet protein. Northern blot analysis was performed using HEL cell total RNA. The GPIIb cDNA hybridized to a 4.1kb mRNA while the GPIIIa cDNA hybridized to a 5.8kb mRNA. This indicates that the two cDNAs do not cross-hybridize and suggests that GPIIb and GPIIIa are encoded by separate genes. The availability of these cDNA for GPIIb and GPIIIa will facilitate study of the structure and function of the proteins and will aid in clarifying their relationship to other adhesive protein receptors.
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Reports on the topic "Domoic acid"

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Wisniewski, Michael, Samir Droby, John Norelli, Dov Prusky, and Vera Hershkovitz. Genetic and transcriptomic analysis of postharvest decay resistance in Malus sieversii and the identification of pathogenicity effectors in Penicillium expansum. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7597928.bard.

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Use of Lqh2 mutants (produced at TAU) and rNav1.2a mutants (produced at the US side) for identifying receptor site-3: Based on the fact that binding of scorpion alpha-toxins is voltage-dependent, which suggests toxin binding at the mobile voltage-sensing region, we analyzed which of the toxin bioactive domains (Core-domain or NC-domain) interacts with the DIV Gating-module of rNav1.2a. This analysis was based on the assumption that the dissociation of toxin mutants upon depolarization would vary from that of the unmodified toxin should the substitutions affect a site of interaction with the channel Gating-module. Using a series of toxin mutants (mutations at both domains) and two channel mutants that were shown to reduce the sensitivity to scorpion alpha-toxins, and by comparison of depolarization-driven dissociation of Lqh2 derivatives off their binding site at rNav1.2a mutant channels we found that the toxin Core-domain interacts with the Gating-module of DIV. Details of the experiments and results appear in Guret al (2011). Mapping receptor site 3 at Nav1.2a by extensive channel mutagenesis (Seattle): Since previous studies with photoaffinity labeling and antibody mapping implicated domains I and IV in scorpion alpha-toxin binding, Nav1.2 channel mutants containing substitutions at these extracellular regions were expressed and tested for receptor function by whole-cell voltage clamp. Of a large number of channel mutants, T1560A, F1610A, and E1613A in domain IV had ~5.9-, ~10.7-, and ~3.9-fold lower affinities for the scorpion toxin Lqh2, respectively, and mutant E1613R had 73-fold lower affinity. Toxin dissociation was accelerated by depolarization for both wild-type and mutants, and the rates of dissociation were also increased by mutations T1560A, F1610A and E1613A. In contrast, association rates for these three mutant channels at negative membrane potentials were not significantly changed and were not voltage-dependent. These results indicated that Thr1560 in the S1-S2 loop, Phe1610 in the S3 segment, and Glu1613 in the S3-S4 loop in domain IV participate in toxin binding. T393A in the SS2-S6 loop in domain I also showed a ~3.4-fold lower affinity for Lqh2, indicating that this extracellular loop may form a secondary component of the toxin binding site. Analysis with the Rosetta-Membrane algorithm revealed a three-dimensional model of Lqh2 binding to the voltage sensor in a resting state. In this model, amino acid residues in an extracellular cleft formed by the S1-S2 and S3-S4 loops in domain IV that are important for toxin binding interact with amino acid residues on two faces of the wedge-shaped Lqh2 molecule that are important for toxin action. The conserved gating charges in the S4 transmembrane segment are in an inward position and likely form ion pairs with negatively charged amino acid residues in the S2 and S3 segments (Wang et al 2011; Gurevitz 2012; Gurevitzet al 2013).
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Nafikov, Rafael, Jon Schoonmaker, James M. Reecy, Diane Moody Spurlock, Donald C. Beitz, Kenneth J. Koehler, and Jenny Minick-Bormann. Effects of A17924G Genotypes Associated with Thioesterase Domain of Fatty Acid Synthase and K232A Genotypes of Diacylglycerol Acyltransferase-1 on Milk Fatty Acid Composition in Holstein Dairy Cows. Ames (Iowa): Iowa State University, January 2009. http://dx.doi.org/10.31274/ans_air-180814-983.

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Yalovsky, Shaul, and Julian Schroeder. The function of protein farnesylation in early events of ABA signal transduction in stomatal guard cells of Arabidopsis. United States Department of Agriculture, January 2002. http://dx.doi.org/10.32747/2002.7695873.bard.

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Loss of function mutations in the farnesyltransferase β subunit gene ERA1 (enhanced response to abscisic acid), cause abscisic acid hypersensitivity in seedlings and in guard cells. This results in slowed water loss of plants in response to drought. Farnesyltransferase (PFT) catalyses the attachment of the 15-carbon isoprenoid farnesyl to conserved cysteine residues located in a conserved C-terminal domain designated CaaX box. PFT is a heterodimeric protein comprised of an a and b sununits. The a subunit is shared between PFT and geranylgeranyltransferase-I (PGGTI) which catalyses the attachemt of the 20-carbon isoprenoid geranylgeranyl to CaaX box proteins in which the last amino acid is almost always leucine and in addition have a polybasic domain proximal to the CaaL box. Preliminary data presented in the proposal showed that increased cytoplasmic Ca2+ concentration in stomal guard cells in response to non-inductive ABA treatements. The goals set in the proposal were to characterize better how PFT (ERA1) affects ABA induced Ca2+ concentrations in guard cells and to identify putative CaaX box proteins which function as negative regulators of ABA signaling and which function is compromised in era1 mutant plants. To achieve these goals we proposed to use camelion Ca2+ sensor protein, high throughput genomic to identify the guard cell transcriptome and test prenylation of candidate proteins. We also proposed to focus our efforts of RAC small GTPases which are prenylated proteins which function in signaling. Our results show that farnesyltransferaseprenylates protein/s that act between the points of ABA perception and the activation of plasma membrane calcium influx channels. A RAC protein designated AtRAC8/AtRop10 also acts in negative regulation of ABA signaling. However, we discovered that this protein is palmitoylated and not prenylated although it contains a C-terminal CXXX motif. We further discovered a unique C-terminal sequence motif required for membrane targeting of palmitoylatedRACs and showed that their function is prenylation independent. A GC/MS based method for expression in plants, purification and analysis of prenyl group was developed. This method would allow highly reliable identification of prenylated protein. Mutants in the shared α subunit of PFT and PGGT-I was identified and characterized and was shown to be ABA hypersensitive but less than era1. This suggested that PFT and PGGT-I have opposing functions in ABA signaling. Our results enhanced the understanding of the role of protein prenylation in ABA signaling and drought resistance in plants with the implications of developing drought resistant plants. The results of our studies were published 4 papers which acknowledge support from BARD.
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Fluhr, Robert, and Maor Bar-Peled. Novel Lectin Controls Wound-responses in Arabidopsis. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7697123.bard.

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Innate immune responses in animals and plants involve receptors that recognize microbe-associated molecules. In plants, one set of this defense system is characterized by large families of TIR–nucleotide binding site–leucine-rich repeat (TIR-NBS-LRR) resistance genes. The direct interaction between plant proteins harboring the TIR domain with proteins that transmit and facilitate a signaling pathway has yet to be shown. The Arabidopsis genome encodes TIR-domain containing genes that lack NBS and LRR whose functions are unknown. Here we investigated the functional role of such protein, TLW1 (TIR LECTIN WOUNDRESPONSIVE1). The TLW1 gene encodes a protein with two domains: a TIR domain linked to a lectin-containing domain. Our specific aim in this proposal was to examine the ramifications of the TL1-glycan interaction by; A) The functional characterization of TL1 activity in the context of plant wound response and B) Examine the hypothesis that wounding induced specific polysaccharides and examine them as candidates for TL-1 interactive glycan compounds. The Weizmann group showed TLW1 transcripts are rapidly induced by wounding in a JA-independent pathway and T-DNA-tagged tlw1 mutants that lack TLW1 transcripts, fail to initiate the full systemic wound response. Transcriptome methodology analysis was set up and transcriptome analyses indicates a two-fold reduced level of JA-responsive but not JA-independent transcripts. The TIR domain of TLW1 was found to interact directly with the KAT2/PED1 gene product responsible for the final b-oxidation steps in peroxisomal-basedJA biosynthesis. To identify potential binding target(s) of TL1 in plant wound response, the CCRC group first expressed recombinant TL1 in bacterial cells and optimized conditions for the protein expression. TL1 was most highly expressed in ArcticExpress cell line. Different types of extraction buffers and extraction methods were used to prepare plant extracts for TL1 binding assay. Optimized condition for glycan labeling was determined, and 2-aminobenzamide was used to label plant extracts. Sensitivity of MALDI and LC-MS using standard glycans. THAP (2,4,6- Trihydroxyacetophenone) showed minimal background peaks at positive mode of MALDI, however, it was insensitive with a minimum detection level of 100 ng. Using LC-MS, sensitivity was highly increased enough to detect 30 pmol concentration. However, patterns of total glycans displayed no significant difference between different extraction conditions when samples were separated with Dionex ICS-2000 ion chromatography system. Transgenic plants over-expressing lectin domains were generated to obtain active lectin domain in plant cells. Insertion of the overexpression construct into the plant genome was confirmed by antibiotic selection and genomic DNA PCR. However, RT-PCR analysis was not able to detect increased level of the transcripts. Binding ability of azelaic acid to recombinant TL1. Azelaic acid was detected in GST-TL1 elution fraction, however, DHB matrix has the same mass in background signals, which needs to be further tested on other matrices. The major findings showed the importance of TLW1 in regulating wound response. The findings demonstrate completely novel and unexpected TIR domain interactions and reveal a control nexus and mechanism that contributes to the propagation of wound responses in Arabidopsis. The implications are to our understanding of the function of TIR domains and to the notion that early molecular events occur systemically within minutes of a plant sustaining a wound. A WEB site (http://genome.weizmann.ac.il/hormonometer/) was set up that enables scientists to interact with a collated plant hormone database.
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Young, Erin, Cem Kuscu, Christine Watkins, and Murat Dogan. Using CRISPR Gene Editing to Prevent Accumulation of Lipids in Hepatocytes. University of Tennessee Health Science Center, January 2022. http://dx.doi.org/10.21007/com.lsp.2022.0007.

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CRISPR gene editing is a molecular technology that can be used to silence gene expression. In this experiment, genes that are known to play a role in lipid accumulation in hepatocytes were targeted. Specifically, levels of fatty acid transport proteins 2 and 5 (FATP2 & 5) have been shown to be elevated in cases of non-alcoholic fatty liver disease. The goal of this experiment was to reduce expression of these genes by using a dead Cas9 (dCas9) protein with an attached inhibitory domain (KRAB) that acts on the promotor region. When measuring the mRNA expression, it was determined that the levels of the CRISPR-modified gene products were significantly reduced compared to the control. However, the same extent of inhibition was not consistently observed when conducting flow cytometry. Current work is aimed at discovering why lipid accumulation is not inhibited to the expected degree based on the results of mRNA expression.
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Fromm, Hillel, and Joe Poovaiah. Calcium- and Calmodulin-Mediated Regulation of Plant Responses to Stress. United States Department of Agriculture, September 1993. http://dx.doi.org/10.32747/1993.7568096.bard.

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We have taken a molecular approach to clone cellular targets of calcium/calmodulin (Ca2+/CaM). A 35S-labeled recombinant CaM was used as a probe to screen various cDNA expression libraries. One of the isolated clones from petunia codes for the enzyme glutamate decarboxylase (GAD) which catalyzes the conversion of glutamate to g-aminobutyric acid (GABA). The activity of plant GAD has been shown to be dramatically enhanced in response to cold and heat shock, anoxia, drought, mechanical manipulations and by exogenous application of the stress phytohormone ABA in wheat roots. We have purified the recombinant GAD by CaM-affinity chromatography and studied its regulation by Ca2+/CaM. At a physiological pH range (7.0-7.5), the purified enzyme was inactive in the absence of Ca2+ and CaM but could be stimulated to high levels of activity by the addition of exogenous CaM (K0.5 = 15 nM) in the presence of Ca2+ (K 0.5 = 0.8 mM). Neither Ca2+ nor CaM alone had any effect on GAD activity. Transgenic tobacco plants expressing a mutant petunia GAD lacking the CaM-binding domain, or transgenic plants expressing the intact GAD were prepared and studied in detail. We have shown that the CaM-binding domain is necessary for the regulation of glutamate and GABA metabolism and for normal plant development. Moreover, we found that CaM is tightly associated with a 500 kDa GAD complex. The tight association of CaM with its target may be important for the rapid modulation of GAD activity by Ca2+ signaling in response to stresses.
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Knight, R. D., and B. A. Kjarsgaard. Comparative pXRF and Lab ICP-ES/MS methods for mineral resource assessment, Northwest Territories. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/331239.

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The Geological Survey of Canada undertook a mineral resource assessment for a proposed national park in northern Canada (~ 33,500 km2) spanning the transition from boreal forest to barren lands tundra. Bedrock geology of this region is complex and includes the Archean Slave Craton, the Archean and Paleoproterozoic Rae domain of the Churchill Province, the Paleoproterozoic Thelon and Taltson magmatic-tectonic zones, and the Paleoproterozoic East Arm sedimentary basin. The area has variable mineral potential for lode gold, kimberlite-hosted diamonds, VMS, vein uranium and copper, SEDEX, as well as other deposit types. A comparison of analytical methods was carried out after processing the field collected samples to acquire both the &amp;lt; 2 mm and for the &amp;lt; 0.063 mm size fractions for 241 surficial sediment (till) samples, collected using a 10 x 10 km grid. Analytical methods comprised: 1) aqua regia followed by ICP-MS analysis, 2) 4-acid hot dissolution followed by ICP-ES/MS analysis, 3) lithium metaborate/tetraborate fusion methods followed by ICP-ES for major elements and ICP-MS for trace elements and, 4) portable XRF on dried, non-sieved sediment samples subjected to a granular segregation processing technique (to produce a clay-silt proxy) for seventeen elements (Ba, Ca, Cr, Cu, Fe, K, Mn, Ni, Pb, Rb, Sr, Th, Ti, U, V, Zn, and Zr) Results indicate that pXRF data do not replicate exactly the laboratory 4-acid and fusion data (in terms of precision and accuracy), but the relationship between the datasets is systematic as displayed in x-y scattergrams. Interpolated single element plots indicate that till samples with anomalies of high and low pXRF concentration levels are synonymous with high and low laboratory-based analytical concentration levels, respectively. The pXRF interpolations thus illustrate the regional geochemical trends, and most importantly, the significant geochemical anomalies in the surficial samples. These results indicate that pXRF spectrometry for a subset of elements is comparable to traditional laboratory methods. pXRF spectrometry also provides the benefit of rapid analysis and data acquisition that has a direct influence on real time sampling designs. This information facilitates efficient and cost-effective field projects (i.e. where used to identify regions of interest for high density sampling), and to prioritize samples to be analyzed using traditional geochemical methods. These tactics should increase the efficiency and success of a mineral exploration and/or environmental sampling programs.
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Rafaeli, Ada, and Russell Jurenka. Molecular Characterization of PBAN G-protein Coupled Receptors in Moth Pest Species: Design of Antagonists. United States Department of Agriculture, December 2012. http://dx.doi.org/10.32747/2012.7593390.bard.

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The proposed research was directed at determining the activation/binding domains and gene regulation of the PBAN-R’s thereby providing information for the design and screening of potential PBAN-R-blockers and to indicate possible ways of preventing the process from proceeding to its completion. Our specific aims included: (1) The identification of the PBAN-R binding domain by a combination of: (a) in silico modeling studies for identifying specific amino-acid side chains that are likely to be involved in binding PBAN with the receptor and; (b) bioassays to verify the modeling studies using mutant receptors, cell lines and pheromone glands (at tissue and organism levels) against selected, designed compounds to confirm if compounds are agonists or antagonists. (2) The elucidation ofthemolecular regulationmechanisms of PBAN-R by:(a) age-dependence of gene expression; (b) the effect of hormones and; (c) PBAN-R characterization in male hair-pencil complexes. Background to the topic Insects have several closely related G protein-coupled receptors (GPCRs) belonging to the pyrokinin/PBAN family, one with the ligand pheromone biosynthesis activating neuropeptide or pyrokinin-2 and another with diapause hormone or pyrokinin-1 as a ligand. We were unable to identify the diapause hormone receptor from Helicoverpa zea despite considerable effort. A third, related receptor is activated by a product of the capa gene, periviscerokinins. The pyrokinin/PBAN family of GPCRs and their ligands has been identified in various insects, such as Drosophila, several moth species, mosquitoes, Triboliumcastaneum, Apis mellifera, Nasoniavitripennis, and Acyrthosiphon pisum. Physiological functions of pyrokinin peptides include muscle contraction, whereas PBAN regulates pheromone production in moths plus other functions indicating the pleiotropic nature of these ligands. Based on the alignment of annotated genomic sequences, the primary and secondary structures of the pyrokinin/PBAN family of receptors have similarity with the corresponding structures of the capa or periviscerokinin receptors of insects and the neuromedin U receptors found in vertebrates. Major conclusions, solutions, achievements Evolutionary trace analysisof receptor extracellular domains exhibited several class-specific amino acid residues, which could indicate putative domains for activation of these receptors by ligand recognition and binding. Through site-directed point mutations, the 3rd extracellular domain of PBAN-R was shown to be critical for ligand selection. We identified three receptors that belong to the PBAN family of GPCRs and a partial sequence for the periviscerokinin receptor from the European corn borer, Ostrinianubilalis. Functional expression studies confirmed that only the C-variant of the PBAN-R is active. We identified a non-peptide agonist that will activate the PBAN-receptor from H. zea. We determined that there is transcriptional control of the PBAN-R in two moth species during the development of the pupa to adult, and we demonstrated that this transcriptional regulation is independent of juvenile hormone biosynthesis. This transcriptional control also occurs in male hair-pencil gland complexes of both moth species indicating a regulatory role for PBAN in males. Ultimate confirmation for PBAN's function in the male tissue was revealed through knockdown of the PBAN-R using RNAi-mediated gene-silencing. Implications, both scientific and agricultural The identification of a non-peptide agonist can be exploited in the future for the design of additional compounds that will activate the receptor and to elucidate the binding properties of this receptor. The increase in expression levels of the PBAN-R transcript was delineated to occur at a critical period of 5 hours post-eclosion and its regulation can now be studied. The mysterious role of PBAN in the males was elucidated by using a combination of physiological, biochemical and molecular genetics techniques.
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9

Locy, Robert D., Hillel Fromm, Joe H. Cherry, and Narendra K. Singh. Regulation of Arabidopsis Glutamate Decarboxylase in Response to Heat Stress: Modulation of Enzyme Activity and Gene Expression. United States Department of Agriculture, January 2001. http://dx.doi.org/10.32747/2001.7575288.bard.

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Most plants accumulate the nonprotein amino acid, g-aminobutyric acid (GABA), in response to heat stress. GABA is made from glutamate in a reaction catalyzed by glutamate decarboxylase (GAD), an enzyme that has been shown by the Israeli PI to be a calmodulin (CaM) binding protein whose activity is regulated in vitro by calcium and CaM. In Arabidopsis there are at least 5 GAD genes, two isoforms of GAD, GAD1 and GAD2, are known to be expressed, both of which appear to be calmodulin-binding proteins. The role of GABA accumulation in stress tolerance remains unclear, and thus the objectives of the proposed work are intended to clarify the possible roles of GABA in stress tolerance by studying the factors which regulate the activity of GAD in vivo. Our intent was to demonstrate the factors that mediate the expression of GAD activity by analyzing the promoters of the GAD1 and GAD2 genes, to determine the role of stress induced calcium signaling in the regulation of GAD activity, to investigate the role of phosphorylation of the CaM-binding domain in the regulation of GAD activity, and to investigate whether ABA signaling could be involved in GAD regulation via the following set of original Project Objectives: 1. Construction of chimeric GAD1 and GAD2 promoter/reporter gene fusions and their utilization for determining cell-specific expression of GAD genes in Arabidopsis. 2. Utilizing transgenic plants harboring chimeric GAD1 promoter-luciferase constructs for isolating mutants in genes controlling GAD1 gene activation in response to heat shock. 3. Assess the role of Ca2+/CaM in the regulation of GAD activity in vivo in Arabidopsis. 4. Study the possible phosphorylation of GAD as a means of regulation of GAD activity. 5. Utilize ABA mutants of Arabidopsis to assess the involvement of this phytohormone in GAD activation by stress stimuli. The major conclusions of Objective 1 was that GAD1 was strongly expressed in the elongating region of the root, while GAD2 was mainly expressed along the phloem in both roots and shoots. In addition, GAD activity was found not to be transcriptionally regulated in response to heat stress. Subsequently, The Israeli side obtained a GAD1 knockout mutation, and in light of the objective 1 results it was determined that characterization of this knockout mutation would contribute more to the project than the proposed Objective 2. The major conclusion of Objective 3 is that heat-stress-induced changes in GAD activity can be explained by heat-stress-induced changes in cytosolic calcium levels. No evidence that GAD activity was transcriptionally or translationally regulated or that protein phosphorylation was involved in GAD regulation (objective 4) was obtained. Previously published data by others showing that in wheat roots ABA regulated GABA accumulation proved not to be the case in Arabidopsis (Objective 5). Consequently, we put the remaining effort in the project into the selection of mutants related to temperature adaptation and GABA utilization and attempting to characterize events resulting from GABA accumulation. A set of 3 heat sensitive mutants that appear to have GABA related mutations have been isolated and partially characterized, and a study linking GABA accumulation to growth stimulation and altered nitrate assimilation were conducted. By providing a better understanding of how GAD activity was and was not regulated in vivo, we have ruled out the use of certain genes for genetically engineering thermotolerance, and suggested other areas of endeavor related to the thrust of the project that may be more likely approaches to genetically engineering thermotolerance.
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10

Sadot, Einat, Christopher Staiger, and Mohamad Abu-Abied. Studies of Novel Cytoskeletal Regulatory Proteins that are Involved in Abiotic Stress Signaling. United States Department of Agriculture, September 2011. http://dx.doi.org/10.32747/2011.7592652.bard.

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In the original proposal we planned to focus on two proteins related to the actin cytoskeleton: TCH2, a touch-induced calmodulin-like protein which was found by us to interact with the IQ domain of myosin VIII, ATM1; and ERD10, a dehydrin which was found to associate with actin filaments. As reported previously, no other dehydrins were found to interact with actin filaments. In addition so far we were unsuccessful in confirming the interaction of TCH2 with myosin VIII using other methods. In addition, no other myosin light chain candidates were found in a yeast two hybrid survey. Nevertheless we have made a significant progress in our studies of the role of myosins in plant cells. Plant myosins have been implicated in various cellular activities, such as cytoplasmic streaming (1, 2), plasmodesmata function (3-5), organelle movement (6-10), cytokinesis (4, 11, 12), endocytosis (4, 5, 13-15) and targeted RNA transport (16). Plant myosins belong to two main groups of unconventional myosins: myosin XI and myosin VIII, both closely related to myosin V (17-19). The Arabidopsis myosin family contains 17 members: 13 myosin XI and four myosin VIII (19, 20). The data obtained from our research of myosins was published in two papers acknowledging BARD funding. To address whether specific myosins are involved with the motility of specific organelles, we cloned the cDNAs from neck to tail of all 17 Arabidopsis myosins. These were fused to GFP and used as dominant negative mutants that interact with their cargo but are unable to walk along actin filaments. Therefore arrested organelle movement in the presence of such a construct shows that a particular myosin is involved with the movement of that particular organelle. While no mutually exclusive connections between specific myosins and organelles were found, based on overexpression of dominant negative tail constructs, a group of six myosins (XIC, XIE, XIK, XI-I, MYA1 and MYA2) were found to be more important for the motility of Golgi bodies and mitochondria in Nicotiana benthamiana and Nicotiana tabacum (8). Further deep and thorough analysis of myosin XIK revealed a potential regulation by head and tail interaction (Avisar et al., 2011). A similar regulatory mechanism has been reported for animal myosin V and VIIa (21, 22). In was shown that myosin V in the inhibited state is in a folded conformation such that the tail domain interacts with the head domain, inhibiting its ATPase and actinbinding activities. Cargo binding, high Ca2+, and/or phosphorylation may reduce the interaction between the head and tail domains, thus restoring its activity (23). Our collaborative work focuses on the characterization of the head tail interaction of myosin XIK. For this purpose the Israeli group built yeast expression vectors encoding the myosin XIK head. In addition, GST fusions of the wild-type tail as well as a tail mutated in the amino acids that mediate head to tail interaction. These were sent to the US group who is working on the isolation of recombinant proteins and performing the in vitro assays. While stress signals involve changes in Ca2+ levels in plants cells, the cytoplasmic streaming is sensitive to Ca2+. Therefore plant myosin activity is possibly regulated by stress. This finding is directly related to the goal of the original proposal.
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