A total of 133 shellfish samples were collected in seven cities of Shandong Province,China,from May to October,2019.The domoic acid(DA)concentrations were determined by liquid chromatographytandem mass spectrometry(LC...A total of 133 shellfish samples were collected in seven cities of Shandong Province,China,from May to October,2019.The domoic acid(DA)concentrations were determined by liquid chromatographytandem mass spectrometry(LC-MS/MS),and their distribution characteristics were investigated.DA concentration was detected high in over 1/3(36.1%)of the samples of four kinds of shellfish in all three seasons in range from 0 to 102μg/kg.The highest DA concentrations were 102,101,36.7,and 10.2μg/kg in Crassostrea gigas,Chlamys farreri,Mactra veneriformis,and Mytilus edulis,respectively.Geographically,Yantai(22.0μg/kg)and Weihai(16.9μg/kg)showed relatively high concentrations of DA,whereas Rizhao and Dongying presented only 0.85-and 1.76-μg/kg DA,respectively.DA concentrations in the shellfish samples were strongly related to seasonal changes,being significantly higher in autumn and summer than that in spring.The DA risk exposure assessments indicate that dietary seafood consumption did not pose a health threat to general human population.In addition,three isomers(isoA,isoD,isoE)and 5′-epimer DA were detected in 3.00%-15.80%of the shellfish samples.This study is the first to observe DA and its isomers in shellfish samples of Shandong Province.The results demonstrate that DA contamination is very common and should be continuously monitored.展开更多
A simple method for spiking formulated feed with domoic acid (DA) was developed in this study. DA feed was prepared by mixing 0.15 mL 100 μg mL-1 DA with 0.1 g formulated feed, and drying the mixture at room temperat...A simple method for spiking formulated feed with domoic acid (DA) was developed in this study. DA feed was prepared by mixing 0.15 mL 100 μg mL-1 DA with 0.1 g formulated feed, and drying the mixture at room temperature for 2 h. The prepared DA feed contained 0.19 pg DA per particle. Of the added DA, 46.72% was retained in the feed. Relatively high DA retention (about 50%) was recorded after DA feed was soaked in water for 2 h. Exposure to DA feed for 7 d did not cause the increase of tissue DA level of adult king scallop (Pecten maximus) significantly in 60 d. The increase of their gonad index after DA exposure was not significantly different from the control. No significant change in DA level was found in spermary, ovary or fertilized eggs after DA exposure. These results indicated that DA excretion may be more efficient than DA accumulation under the current experimental conditions, and the mechanism of domoic acid incorporation in P. maximus may involve intracellular biotransformation.展开更多
The clinical presentation of schizophrenia involves a variety of symptoms, which in many cases include hallucinations and delusions. Experimentally revealed alterations in both pre-pulse inhibition (PPI) and latent in...The clinical presentation of schizophrenia involves a variety of symptoms, which in many cases include hallucinations and delusions. Experimentally revealed alterations in both pre-pulse inhibition (PPI) and latent inhibition (LI) are also apparent in individuals afflicted with this disorder. Many have speculated that altered synaptic connections are, in part, responsible for this subset of behavioral abnormalities. We have previously reported that neonatal chronic low-dose injections of domoic acid (DOM) produce adult rats with deficits in PPI and LI. The current study was conducted to determine whether this toxin-treatment would alter the degree of apoptosis occurring in the developing brain. Results revealed significant decreases in caspase-3 within the right prelimbic cortex (PrL) in both male and female DOM-treated rats suggesting that even modest alterations in glutamate (Glu) signaling during critical periods of central nervous system (CNS) maturation will modify ontogenetic processes in the prefrontal cortex (PFC) of the juvenile rat.展开更多
Advances in sensor technology have allowed the significant progress in the monitoring of noxious compounds in the sea, providing real-time detection so as to prevent risks associated with the diffusion and dispersion ...Advances in sensor technology have allowed the significant progress in the monitoring of noxious compounds in the sea, providing real-time detection so as to prevent risks associated with the diffusion and dispersion of toxic substances in the environment. An important element in the overall picture is the harmful algal blooms which pose serious threats to marine ecosystems through the production of toxins that accumulate in filter-feeders and ultimately impact both human health and fisheries. Domoic acid is a neurotoxic amino acid produced by marine planktonic diatoms of the genus Pseudo-nitzschia. Here we monitored domoic acid production by natural Pseudo-nitzschia populations in phytoplankton samples collected along the Middle Tyrrhenian coast, over the course of one year, using selective immunosensors based on screenprinted electrodes, using differential pulse voltammetry as the electrochemical technique, to yield quantitative outputs. In this work, disposable devices have been applied for monitoring the production of domoic acid on algal extracts and the results have been validated by conventional high pressure liquid chromatography-ultraviolet detection methods. The data obtained revealed the presence of domoic acid in Italian phytoplankton, especially in coastal impacted areas, highlighting the potential risk of toxin entering into marine food webs and the environment. Immunosensors based on screen-printed electrodes prove to be effective tools for annual monitoring of domoic acid in seawater samples, thus providing a reliable early warning system relative to health and economic impact of algal toxins.展开更多
The purpose of the present study was to determine whether early alterations in glutamate signaling, via daily injections of the glutamate agonist, domoic acid (DOM;20 μg/kg), during a critical period of CNS developme...The purpose of the present study was to determine whether early alterations in glutamate signaling, via daily injections of the glutamate agonist, domoic acid (DOM;20 μg/kg), during a critical period of CNS development (PND 8 - 14), would result in temporal memory deficits and/or alterations in tyrosine hydroxylase (TH) immunoreactivity. As adults, subjects were assessed for temporal memory ability using a recency discrimination paradigm. Both number and duration of exploratory contacts directed at familiar objects, differing by one hour in recall delay, were measured. Analyses revealed that DOM-treated females demonstrated temporal memory dysfunction, as evidenced in a significantly lower proportion of total exploratory behaviour directed toward the remote object. Integrity of the dopamine system was assessed using immunohistochemistry to examine TH immunoreactivity in the prefrontal cortex (PFC) and nucleus accumbens (NAcc). Sections obtained from DOM-treated males had significantly less TH immunoreactivity in the right mPFC, while DOM-treated females had significantly greater TH immunoreactivity in the left core and right shell of the NAcc. These findings are discussed in context of early alterations to glutamate signaling in the development of human neuropsychiatric disorders.展开更多
Domoic acid (DA) is a neuroexcitatory amino acid that is produced by Pseudo-nitzschia during harmful algal blooms (HAB). Accumulation of DA can be transferred through food chain and cause neuronal damage in marine ani...Domoic acid (DA) is a neuroexcitatory amino acid that is produced by Pseudo-nitzschia during harmful algal blooms (HAB). Accumulation of DA can be transferred through food chain and cause neuronal damage in marine animal and in human. Like other algal toxins, DA was suggested to increase the oxidative stress and increase the detoxification-related gene expression in fish. The widely used food antioxidant, tert-butylhydroquinone (tBHQ), was known to induce a wide range of antioxidative potentials such as elevation of the glutathione levels and glutathione S-transferases (GSTs), via the activation of antioxidant response elements (AREs). In this study, the influences of dietary tBHQ on domoic acid (DA) metabolism and detoxification-related gene transcription were investigated both in vivo and in vitro. Oral administration of tBHQ resulted in significant decreases of DA accumulation of liver tissues in which red sea bream were fed with a single dose of 10 mg DA and 100 mg tBHQ per kg body weight per fish. Real-time PCR further revealed that the mRNA levels of AHR/ARNT/CYP1A1/GSTA1/GSTR were up-regulated in the above liver tissues at 72 h post tBHQ treatment. In consistence, tBHQ exposure also resulted in increased mRNA transcription of GSTA1, GSTA2 and GSTR in cultured red sea bream hepatocytes. Collectively, our findings in this research suggested that the dietary intake of tBHQ accelerated DA metabolism in fish, through mechanisms involving altered transcription of detoxification- related liver genes.展开更多
The interaction between domoic acid(DA) and 18-mer double-stranded DNA(dsDNA) was investigated by using microchip-based non-gel sieving electrophoresis. For the 18-mer dsDNA with a sequence of 3′-GCATTGGTTGACGTTGCA-5...The interaction between domoic acid(DA) and 18-mer double-stranded DNA(dsDNA) was investigated by using microchip-based non-gel sieving electrophoresis. For the 18-mer dsDNA with a sequence of 3′-GCATTGGTTGACGTTGCA-5′, the amount of free dsDNA decreases with the increase of the added DA and also with the increase of reactive time. Meanwhile, the newly-produced two peaks were observed. The experimental results show that there is a strong interaction between DA and the 18-mer dsDNA. DA makes the degradation of the 18-mer dsDNA. The non-gel sieving electrophoresis on microchip is a rapid, convenient, highly sensitive method for studying the interaction between DNA and small molecules.展开更多
基金Supported by the Science&Technology Basic Resources Investigation Program of China(No.2018FY100200)the National Natural Science Foundation of China(Nos.32072329,41976110)+1 种基金the Central PublicInterest Scientifi c Institution Basal Research Fund,CAFS(No.2020TD71)the Earmarked Fund for CARS(CARS-49)。
文摘A total of 133 shellfish samples were collected in seven cities of Shandong Province,China,from May to October,2019.The domoic acid(DA)concentrations were determined by liquid chromatographytandem mass spectrometry(LC-MS/MS),and their distribution characteristics were investigated.DA concentration was detected high in over 1/3(36.1%)of the samples of four kinds of shellfish in all three seasons in range from 0 to 102μg/kg.The highest DA concentrations were 102,101,36.7,and 10.2μg/kg in Crassostrea gigas,Chlamys farreri,Mactra veneriformis,and Mytilus edulis,respectively.Geographically,Yantai(22.0μg/kg)and Weihai(16.9μg/kg)showed relatively high concentrations of DA,whereas Rizhao and Dongying presented only 0.85-and 1.76-μg/kg DA,respectively.DA concentrations in the shellfish samples were strongly related to seasonal changes,being significantly higher in autumn and summer than that in spring.The DA risk exposure assessments indicate that dietary seafood consumption did not pose a health threat to general human population.In addition,three isomers(isoA,isoD,isoE)and 5′-epimer DA were detected in 3.00%-15.80%of the shellfish samples.This study is the first to observe DA and its isomers in shellfish samples of Shandong Province.The results demonstrate that DA contamination is very common and should be continuously monitored.
文摘A simple method for spiking formulated feed with domoic acid (DA) was developed in this study. DA feed was prepared by mixing 0.15 mL 100 μg mL-1 DA with 0.1 g formulated feed, and drying the mixture at room temperature for 2 h. The prepared DA feed contained 0.19 pg DA per particle. Of the added DA, 46.72% was retained in the feed. Relatively high DA retention (about 50%) was recorded after DA feed was soaked in water for 2 h. Exposure to DA feed for 7 d did not cause the increase of tissue DA level of adult king scallop (Pecten maximus) significantly in 60 d. The increase of their gonad index after DA exposure was not significantly different from the control. No significant change in DA level was found in spermary, ovary or fertilized eggs after DA exposure. These results indicated that DA excretion may be more efficient than DA accumulation under the current experimental conditions, and the mechanism of domoic acid incorporation in P. maximus may involve intracellular biotransformation.
文摘The clinical presentation of schizophrenia involves a variety of symptoms, which in many cases include hallucinations and delusions. Experimentally revealed alterations in both pre-pulse inhibition (PPI) and latent inhibition (LI) are also apparent in individuals afflicted with this disorder. Many have speculated that altered synaptic connections are, in part, responsible for this subset of behavioral abnormalities. We have previously reported that neonatal chronic low-dose injections of domoic acid (DOM) produce adult rats with deficits in PPI and LI. The current study was conducted to determine whether this toxin-treatment would alter the degree of apoptosis occurring in the developing brain. Results revealed significant decreases in caspase-3 within the right prelimbic cortex (PrL) in both male and female DOM-treated rats suggesting that even modest alterations in glutamate (Glu) signaling during critical periods of central nervous system (CNS) maturation will modify ontogenetic processes in the prefrontal cortex (PFC) of the juvenile rat.
文摘Advances in sensor technology have allowed the significant progress in the monitoring of noxious compounds in the sea, providing real-time detection so as to prevent risks associated with the diffusion and dispersion of toxic substances in the environment. An important element in the overall picture is the harmful algal blooms which pose serious threats to marine ecosystems through the production of toxins that accumulate in filter-feeders and ultimately impact both human health and fisheries. Domoic acid is a neurotoxic amino acid produced by marine planktonic diatoms of the genus Pseudo-nitzschia. Here we monitored domoic acid production by natural Pseudo-nitzschia populations in phytoplankton samples collected along the Middle Tyrrhenian coast, over the course of one year, using selective immunosensors based on screenprinted electrodes, using differential pulse voltammetry as the electrochemical technique, to yield quantitative outputs. In this work, disposable devices have been applied for monitoring the production of domoic acid on algal extracts and the results have been validated by conventional high pressure liquid chromatography-ultraviolet detection methods. The data obtained revealed the presence of domoic acid in Italian phytoplankton, especially in coastal impacted areas, highlighting the potential risk of toxin entering into marine food webs and the environment. Immunosensors based on screen-printed electrodes prove to be effective tools for annual monitoring of domoic acid in seawater samples, thus providing a reliable early warning system relative to health and economic impact of algal toxins.
文摘The purpose of the present study was to determine whether early alterations in glutamate signaling, via daily injections of the glutamate agonist, domoic acid (DOM;20 μg/kg), during a critical period of CNS development (PND 8 - 14), would result in temporal memory deficits and/or alterations in tyrosine hydroxylase (TH) immunoreactivity. As adults, subjects were assessed for temporal memory ability using a recency discrimination paradigm. Both number and duration of exploratory contacts directed at familiar objects, differing by one hour in recall delay, were measured. Analyses revealed that DOM-treated females demonstrated temporal memory dysfunction, as evidenced in a significantly lower proportion of total exploratory behaviour directed toward the remote object. Integrity of the dopamine system was assessed using immunohistochemistry to examine TH immunoreactivity in the prefrontal cortex (PFC) and nucleus accumbens (NAcc). Sections obtained from DOM-treated males had significantly less TH immunoreactivity in the right mPFC, while DOM-treated females had significantly greater TH immunoreactivity in the left core and right shell of the NAcc. These findings are discussed in context of early alterations to glutamate signaling in the development of human neuropsychiatric disorders.
基金supported by the National Natural Science Foundation of China (30670367)the National key Basic Research and Program of China (2007AA09Z437)the Fundamental Research Funds for the Central Universities (2010PY010, 2011PY030)
文摘Domoic acid (DA) is a neuroexcitatory amino acid that is produced by Pseudo-nitzschia during harmful algal blooms (HAB). Accumulation of DA can be transferred through food chain and cause neuronal damage in marine animal and in human. Like other algal toxins, DA was suggested to increase the oxidative stress and increase the detoxification-related gene expression in fish. The widely used food antioxidant, tert-butylhydroquinone (tBHQ), was known to induce a wide range of antioxidative potentials such as elevation of the glutathione levels and glutathione S-transferases (GSTs), via the activation of antioxidant response elements (AREs). In this study, the influences of dietary tBHQ on domoic acid (DA) metabolism and detoxification-related gene transcription were investigated both in vivo and in vitro. Oral administration of tBHQ resulted in significant decreases of DA accumulation of liver tissues in which red sea bream were fed with a single dose of 10 mg DA and 100 mg tBHQ per kg body weight per fish. Real-time PCR further revealed that the mRNA levels of AHR/ARNT/CYP1A1/GSTA1/GSTR were up-regulated in the above liver tissues at 72 h post tBHQ treatment. In consistence, tBHQ exposure also resulted in increased mRNA transcription of GSTA1, GSTA2 and GSTR in cultured red sea bream hepatocytes. Collectively, our findings in this research suggested that the dietary intake of tBHQ accelerated DA metabolism in fish, through mechanisms involving altered transcription of detoxification- related liver genes.
文摘目的利用QuEChERS样品制备结合高效液相色谱法建立测定扇贝中记忆缺失性贝类毒素—软骨藻酸(domoic acid,DA)残留的检测方法。方法 QuEChERS样品制备法进行样品前处理,即样品经甲醇:乙腈:水=6:3:1(v:v:v)提取,C18粉末净化,反相高效液相色谱分离,242 nm波长下检测,基质匹配校准曲线外标法定量。结果方法的检测低限(limit of quantitation,LOQ)为1.8μg/g,DA在0.72~30.00μg/m L浓度范围内线性良好(相关系数r=0.9998),在1.8~6.0μg/g添加浓度范围内,平均回收率为90%左右,相对标准偏差(relative standard deviation,RSD)小于5%。结论本实验建方法检测低限完全满足DA 20μg/g的限量要求,且步骤简单、可操作性强、节省时间、试剂用量少、准确度高、精密度好,具有快速高效的特点。
文摘The interaction between domoic acid(DA) and 18-mer double-stranded DNA(dsDNA) was investigated by using microchip-based non-gel sieving electrophoresis. For the 18-mer dsDNA with a sequence of 3′-GCATTGGTTGACGTTGCA-5′, the amount of free dsDNA decreases with the increase of the added DA and also with the increase of reactive time. Meanwhile, the newly-produced two peaks were observed. The experimental results show that there is a strong interaction between DA and the 18-mer dsDNA. DA makes the degradation of the 18-mer dsDNA. The non-gel sieving electrophoresis on microchip is a rapid, convenient, highly sensitive method for studying the interaction between DNA and small molecules.
