Aflatoxin contamination of corn in the field is influenced by several factors. In the southern U.S., insect populations are usually large every year. Drought caused by warmer and drier than normal weather is conducive to A. flavus infection and aflatoxin contamination of corn, Zea mays L. When loose‐husked hybrids are used in the southern U.S., they accentuate insect damage and aflatoxin contamination. The development and breeding of “southern‐type” hybrids is essential for control of preharvest aflatoxin contamination. Molecular biotechnology may make an impact on tackling the complexity of preharvest aflatoxin contamination of corn. Integration of crop management tactics and genetic strategies, conventional or molecular, may constrain the problem and help southern corn growers produce a quality, profitable crop.
{"title":"Integration of Crop Management and Genetics for Control of Preharvest Aflatoxin Contamination of Corn","authors":"N. W. Widstrom, B. Guo, D. Wilson","doi":"10.1081/TXR-120024092","DOIUrl":"https://doi.org/10.1081/TXR-120024092","url":null,"abstract":"Aflatoxin contamination of corn in the field is influenced by several factors. In the southern U.S., insect populations are usually large every year. Drought caused by warmer and drier than normal weather is conducive to A. flavus infection and aflatoxin contamination of corn, Zea mays L. When loose‐husked hybrids are used in the southern U.S., they accentuate insect damage and aflatoxin contamination. The development and breeding of “southern‐type” hybrids is essential for control of preharvest aflatoxin contamination. Molecular biotechnology may make an impact on tackling the complexity of preharvest aflatoxin contamination of corn. Integration of crop management tactics and genetic strategies, conventional or molecular, may constrain the problem and help southern corn growers produce a quality, profitable crop.","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84094398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biologically active natural products were isolated and identified by means of online LC‐bioassay, LC‐NMR, and LC‐MS from Cussonia barteri (Araliaceae), Terminalia macroptera (Combretaceae), Jasminum subtriplinerve (Oleaceae), and Petunia hybrida (Solanaceae). From C. barteri we obtained the novel C18‐polyacetylene (+)‐9(Z),17‐octadecadiene‐12,14‐diyn‐1,11(S),16(S)‐triol (2) along with its acetate 3, and two new quinic acid esters, 1′‐O‐chlorogenoylchlorogenic acid (4) and 1′‐O‐chlorogenoylneochlorogenic acid (5). Chromatographic work up of T. macroptera extracts yielded a new hydrolyzable tannin, isoterchebulin (6), and 4,6‐O‐isoterchebuloyl‐D‐glucose (7) along with some gallic acid derivatives. From J. subtriplinerve six terpene glycosides 13–18 related to anatolioside A (12), and from P. hybrida seven highly molluscicidal sucrose esters 19–22b were isolated.
采用在线液相色谱-生物测定、液相色谱-核磁共振和液相色谱-质谱等方法，从五加科(Cussonia barteri)、combretacae科(Terminalia macroptera)、Jasminum subtriplinerve (Oleaceae)和矮牵牛(Petunia hybrida)中分离鉴定出具有生物活性的天然产物。从巴氏菌中，我们得到了新的C18‐聚乙炔(+)‐9(Z)、17‐十八烯二烯‐12、14‐二烯‐1、11(S)、16(S)‐三醇(2)及其乙酸3，以及两种新的奎宁酸酯，1′‐O‐绿基绿原酸(4)和1′‐O‐绿基新绿原酸(5)。对大翼虫提取物进行色谱分析，得到了一种新的可水解单宁，异terchebulin(6)和4,6‐O‐异terchebuyl - D -葡萄糖(7)以及一些没食子酸衍生物。从亚三萜苷A(12)中分离到6个萜类苷13-18，从杂交草中分离到7个高杀螺性蔗糖酯19-22b。
{"title":"Investigation of Biologically Active Natural Products Using Online LC‐Bioassay, LC‐NMR, and LC‐MS Techniques","authors":"W. Kraus","doi":"10.1081/TXR-120026909","DOIUrl":"https://doi.org/10.1081/TXR-120026909","url":null,"abstract":"Biologically active natural products were isolated and identified by means of online LC‐bioassay, LC‐NMR, and LC‐MS from Cussonia barteri (Araliaceae), Terminalia macroptera (Combretaceae), Jasminum subtriplinerve (Oleaceae), and Petunia hybrida (Solanaceae). From C. barteri we obtained the novel C18‐polyacetylene (+)‐9(Z),17‐octadecadiene‐12,14‐diyn‐1,11(S),16(S)‐triol (2) along with its acetate 3, and two new quinic acid esters, 1′‐O‐chlorogenoylchlorogenic acid (4) and 1′‐O‐chlorogenoylneochlorogenic acid (5). Chromatographic work up of T. macroptera extracts yielded a new hydrolyzable tannin, isoterchebulin (6), and 4,6‐O‐isoterchebuloyl‐D‐glucose (7) along with some gallic acid derivatives. From J. subtriplinerve six terpene glycosides 13–18 related to anatolioside A (12), and from P. hybrida seven highly molluscicidal sucrose esters 19–22b were isolated.","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79991034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Advances in analytical methods and novel detection systems are reviewed from publications from 1995 onwards. The review covers aflatoxins B1, B2, G1, G2, and their metabolites in food, animal feed and biological matrices such as blood and urine. Improved extraction techniques, new clean‐up methods and optimized methods for specific matrices are summarized. This review highlights methods such as thin layer chromatography (TLC) and high performance‐TLC (HPTLC), which are particularly suited to developing countries, and advances that have been made in TLC quantification through low cost detection and scanning systems. Novel developments in detection of aflatoxins are assessed such as the application of surface plasmon resonance biosensors, flow injection monitoring, fibre optic sensors, capillary electrokinetics, electrochemical transduction, and immunological‐based rapid test kits. Recent advances in confirmatory techniques such as liquid chromatography/mass spectrometry (LC/MS) and tandem mass spectrometry (MS/MS) for aflatoxins are also covered. This review summarizes performance data from recent collaborative studies, and assesses the overall quality of analytical data for aflatoxins being produced worldwide, as evidenced by results from various proficiency testing schemes. Although there are only a few recent studies on sampling for aflatoxins, the recent progress in this area is also assessed.
{"title":"Advances in Sampling and Analysis for Aflatoxins in Food and Animal Feed","authors":"J. Gilbert, E. Vargas","doi":"10.1081/TXR-120024099","DOIUrl":"https://doi.org/10.1081/TXR-120024099","url":null,"abstract":"Advances in analytical methods and novel detection systems are reviewed from publications from 1995 onwards. The review covers aflatoxins B1, B2, G1, G2, and their metabolites in food, animal feed and biological matrices such as blood and urine. Improved extraction techniques, new clean‐up methods and optimized methods for specific matrices are summarized. This review highlights methods such as thin layer chromatography (TLC) and high performance‐TLC (HPTLC), which are particularly suited to developing countries, and advances that have been made in TLC quantification through low cost detection and scanning systems. Novel developments in detection of aflatoxins are assessed such as the application of surface plasmon resonance biosensors, flow injection monitoring, fibre optic sensors, capillary electrokinetics, electrochemical transduction, and immunological‐based rapid test kits. Recent advances in confirmatory techniques such as liquid chromatography/mass spectrometry (LC/MS) and tandem mass spectrometry (MS/MS) for aflatoxins are also covered. This review summarizes performance data from recent collaborative studies, and assesses the overall quality of analytical data for aflatoxins being produced worldwide, as evidenced by results from various proficiency testing schemes. Although there are only a few recent studies on sampling for aflatoxins, the recent progress in this area is also assessed.","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77661443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of Aspergillus flavus inoculation techniques has played an important part in developing corn (Zea mays L.) germplasm resistant to aflatoxin contamination. Corn genotypes evaluated for aflatoxin resistance in field studies must be artificially inoculated due to the sporadic nature of aflatoxin contamination from year to year. A number of different inoculation techniques are used by researchers in the South and Midwest. Field inoculation techniques either wound developing kernels or leave the kernels intact. Non‐wounding techniques apply A. flavus conidia to exposed silks or silks inside the husks without damaging kernels. Wounding techniques deliver A. flavus conidia onto kernels that have been mechanically damaged. Inoculation techniques utilizing ear feeding insects to vector conidia have also been used in field studies. Environmental conditions such as ambient temperature and drought stress appear to have a significant impact on artificial inoculations. Laboratory evaluation techniques have been developed to confirm aflatoxin resistance identified in corn genotypes in the field. Color mutants and transformants of Aspergillus spp. have been used in field and laboratory studies to identify resistant genotypes. More efficient, less labor intensive, and less costly inoculation techniques need to be developed to aid in the production of aflatoxin resistant corn hybrids.
{"title":"Inoculation Techniques Used to Quantify Aflatoxin Resistance in Corn","authors":"G. Windham, W. Williams, P. Buckley, H. Abbas","doi":"10.1081/TXR-120024096","DOIUrl":"https://doi.org/10.1081/TXR-120024096","url":null,"abstract":"The development of Aspergillus flavus inoculation techniques has played an important part in developing corn (Zea mays L.) germplasm resistant to aflatoxin contamination. Corn genotypes evaluated for aflatoxin resistance in field studies must be artificially inoculated due to the sporadic nature of aflatoxin contamination from year to year. A number of different inoculation techniques are used by researchers in the South and Midwest. Field inoculation techniques either wound developing kernels or leave the kernels intact. Non‐wounding techniques apply A. flavus conidia to exposed silks or silks inside the husks without damaging kernels. Wounding techniques deliver A. flavus conidia onto kernels that have been mechanically damaged. Inoculation techniques utilizing ear feeding insects to vector conidia have also been used in field studies. Environmental conditions such as ambient temperature and drought stress appear to have a significant impact on artificial inoculations. Laboratory evaluation techniques have been developed to confirm aflatoxin resistance identified in corn genotypes in the field. Color mutants and transformants of Aspergillus spp. have been used in field and laboratory studies to identify resistant genotypes. More efficient, less labor intensive, and less costly inoculation techniques need to be developed to aid in the production of aflatoxin resistant corn hybrids.","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89802200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antivenom therapy is still used empirically even though it is over one hundred years old (its discovery by Albert Calmette was published in 1894). This note presents the recent clinical and experimental studies conducted by the Venoms Unit of the Institut Pasteur. It shows in particular the results of pharmacokinetic studies of venom toxins and of the modifications of these kinetics after antivenom administration. The conclusions of these studies show how antivenom therapy can be made more effective and safer through better understanding of its mechanism of action.
{"title":"Pharmacokinetics of Venom Toxins and Their Modification by Antivenom Therapy","authors":"C. Bon","doi":"10.1081/TXR-120019025","DOIUrl":"https://doi.org/10.1081/TXR-120019025","url":null,"abstract":"Antivenom therapy is still used empirically even though it is over one hundred years old (its discovery by Albert Calmette was published in 1894). This note presents the recent clinical and experimental studies conducted by the Venoms Unit of the Institut Pasteur. It shows in particular the results of pharmacokinetic studies of venom toxins and of the modifications of these kinetics after antivenom administration. The conclusions of these studies show how antivenom therapy can be made more effective and safer through better understanding of its mechanism of action.","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80780753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Despite the vast amount of literature on studies about the use of reproductive toxicants in laboratory rats as models, there are no reports documenting the detection of direct sperm DNA damage in rats as a result of exposure to a reproductive toxicant. These studies were initiated to develop methodology for detecting and scoring oxidative sperm DNA damage in Wistar rats. The first of four experiments used the basic Comet Assay to compare sperm collected from xanthotoxin‐treated rats with sperm collected from untreated rats to determine if oxidative sperm DNA damage was detectable. No differences were found between images of sperm from treated and non‐treated samples. During Experiment 2, fresh sperm samples from untreated rats were stored in PBS and then reacted with a 100mg/ml solution of xanthotoxin/acetone. Post‐reaction cells were subjected to mechanical sample grinding or incubation with trypsin in an attempt to disrupt the cell capsule. Again, no differences were recorded. Experiment 3 exposed treated and untreated sperm samples to proteinase K for varying time intervals (30 min – 3 hr) in another effort to disrupt the cell capsule. These proved to be promising, although at the time intervals used in Experiment 3, the entire cell was dissolved. A series of tests were then initiated during Experiment 4 to determine the best buffer and reaction time combination. All things were kept identical to Experiment 3 with the exception that samples were taken at more frequent intervals and a different buffer was used with each sample. The buffers used were PBS, TES, and PBS containing Chelex. The best results were obtained with TES at a 55‐minute time interval. The capsule surrounding the spermatatids proved to be very resilient to most digestive and mechanical agents. The enzyme proteinase K proved to be the best means for disrupting the cell capsule. Proteinase K in a TES buffer worked most effectively for detecting and scoring oxidative sperm DNA damage in Wistar rats.
{"title":"Method for Detecting Toxin‐Induced Gamete DNA Damage in Male Rats","authors":"J. Carsella, D. Caprioglio, M. Diawara","doi":"10.1081/TXR-120026922","DOIUrl":"https://doi.org/10.1081/TXR-120026922","url":null,"abstract":"Despite the vast amount of literature on studies about the use of reproductive toxicants in laboratory rats as models, there are no reports documenting the detection of direct sperm DNA damage in rats as a result of exposure to a reproductive toxicant. These studies were initiated to develop methodology for detecting and scoring oxidative sperm DNA damage in Wistar rats. The first of four experiments used the basic Comet Assay to compare sperm collected from xanthotoxin‐treated rats with sperm collected from untreated rats to determine if oxidative sperm DNA damage was detectable. No differences were found between images of sperm from treated and non‐treated samples. During Experiment 2, fresh sperm samples from untreated rats were stored in PBS and then reacted with a 100mg/ml solution of xanthotoxin/acetone. Post‐reaction cells were subjected to mechanical sample grinding or incubation with trypsin in an attempt to disrupt the cell capsule. Again, no differences were recorded. Experiment 3 exposed treated and untreated sperm samples to proteinase K for varying time intervals (30 min – 3 hr) in another effort to disrupt the cell capsule. These proved to be promising, although at the time intervals used in Experiment 3, the entire cell was dissolved. A series of tests were then initiated during Experiment 4 to determine the best buffer and reaction time combination. All things were kept identical to Experiment 3 with the exception that samples were taken at more frequent intervals and a different buffer was used with each sample. The buffers used were PBS, TES, and PBS containing Chelex. The best results were obtained with TES at a 55‐minute time interval. The capsule surrounding the spermatatids proved to be very resilient to most digestive and mechanical agents. The enzyme proteinase K proved to be the best means for disrupting the cell capsule. Proteinase K in a TES buffer worked most effectively for detecting and scoring oxidative sperm DNA damage in Wistar rats.","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75980924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The geographic variations of phospholipases A2 (PLAs) in the venom of four medically important pit vipers were investigated. We have studied the PLAs by HPLC‐purification, cDNA cloning and sequencing, mass characterization, and functional classification. We found that: 1) Anti‐platelet acidic PLA isoforms in the venoms of Calloselasma rhodostoma from five southeastern Asian countries, and those of the Crotalus v. viridis from seven American States are differentially expressed depending on locality. The variations could be attributed to their distinct specificities towards the platelets of different prey, and to possible adaptation for playing other functional roles. In contrast, structures of the myonecrotic and the edema‐inducing basic PLAs in both venoms were relatively conserved. 2) A special type of the acidic anti‐platelet PLA is present in the venom of some Protobothrops species. Its expression level is diminished in the snake of the southern or the tropical ranges. 3) The venom of Bamboo tree vipers (Trimeresurus stejnegeri) in Taiwan and China showed extraordinary geographic variations in their acidic and basic PLAs. The high RNA‐polymorphism of their venom proteins may have been derived from interbreeding between several ancestral pit viper species. In addition, migration, isolation of different populations and rapid evolution of the venom proteins to adapt for diversified diets may have resulted in further variations in this venom species.
研究了四种重要毒蛇毒液中磷脂酶A2 (PLAs)的地理差异。我们通过HPLC -纯化、cDNA克隆和测序、质量表征和功能分类研究了plaas。研究发现:1)东南亚5国红口胼鳞虫(Calloselasma rhodostoma)和美洲7国Crotalus v. viridis毒液中抗血小板酸性聚乳酸(PLA)异构体的表达因地而异。这些变化可能归因于它们对不同猎物血小板的不同特异性，以及为扮演其他功能角色而可能进行的适应。相比之下，两种毒液中肌坏死和诱导水肿的基础plaas的结构相对保守。2)一种特殊类型的酸性抗血小板聚乳酸存在于一些原throps物种的毒液中。它的表达水平在南部或热带地区的蛇中减少。3)中国和台湾地区竹蝰蛇(Trimeresurus stejnegeri)毒液的酸性和碱性成分存在显著的地理差异。它们毒液蛋白的高RNA多态性可能来源于几种祖先毒蛇之间的杂交。此外，迁徙、不同种群的隔离和毒液蛋白质的快速进化以适应多样化的饮食可能导致这种毒液物种的进一步变异。
{"title":"Variations of Phospholipases A2 in the Geographic Venom Samples of Pitvipers","authors":"I. Tsai, Ying-ming Wang, Yi-Hsuan Chen","doi":"10.1081/TXR-120026919","DOIUrl":"https://doi.org/10.1081/TXR-120026919","url":null,"abstract":"The geographic variations of phospholipases A2 (PLAs) in the venom of four medically important pit vipers were investigated. We have studied the PLAs by HPLC‐purification, cDNA cloning and sequencing, mass characterization, and functional classification. We found that: 1) Anti‐platelet acidic PLA isoforms in the venoms of Calloselasma rhodostoma from five southeastern Asian countries, and those of the Crotalus v. viridis from seven American States are differentially expressed depending on locality. The variations could be attributed to their distinct specificities towards the platelets of different prey, and to possible adaptation for playing other functional roles. In contrast, structures of the myonecrotic and the edema‐inducing basic PLAs in both venoms were relatively conserved. 2) A special type of the acidic anti‐platelet PLA is present in the venom of some Protobothrops species. Its expression level is diminished in the snake of the southern or the tropical ranges. 3) The venom of Bamboo tree vipers (Trimeresurus stejnegeri) in Taiwan and China showed extraordinary geographic variations in their acidic and basic PLAs. The high RNA‐polymorphism of their venom proteins may have been derived from interbreeding between several ancestral pit viper species. In addition, migration, isolation of different populations and rapid evolution of the venom proteins to adapt for diversified diets may have resulted in further variations in this venom species.","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76049704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aflatoxins are considered to be potent carcinogens and teratogens to humans and farm animals. A variety of species of the fungal genus Aspergillus (mainly A. flavus and A. parasiticus) synthesize aflatoxins. Spores of these fungi are common in air and soil of agricultural areas of temperate and tropical environments. Because aflatoxigenic fungi are ubiquitous and opportunistic, aflatoxin contamination has become a food safety concern. The chief U.S. crops affected by the threat of contamination with aflatoxin include corn, peanuts, cottonseed, and certain tree nuts. Additionally, aflatoxin contamination has also become an international trade issue. Major trading partners of U.S. agricultural products have set total aflatoxin action threshold levels at four ng/g (ppb). This action level is far below the 20 ppb level recommended by the U.S. Food and Drug administration for domestic foods. Almonds, pistachios and walnuts are one of the major food commodities affected by food safety and trade issues associated with aflatoxin contamination. Commercial domestic production of these tree nuts in the U.S. is entirely in California. Moreover, 50 to 75% of domestically produced tree nuts are exported, chiefly to countries of the European Union (EU), which adhere to the four ppb action threshold level. Scientists at the USDA's Western Regional Research Center and the University of California, Davis' Department of Pomology and Kearney Agricultural Center have developed products and methods to reduce aflatoxin contamination of tree nuts. Control of insect pests in tree nut orchards is a major strategy to curtail aflatoxin contamination. Insect feeding damage can lead to fungal infection and concomitant aflatoxin contamination. This is especially the case with navel orangeworm on pistachio and almond. A new and potent lure has been developed to control codling moth, a major insect pest of walnuts whose feeding damage potentially leads to fungal infection. Through breeding and genetic engineering, new varieties of almonds and walnuts have been developed which are resistant to insect attack. New orchard management strategies have been prescribed to reduce reservoirs of A. flavus in tree nut orchards. A number of saprophytic yeasts, natural to tree nut orchards, have been discovered which show promise as biological control agents of A. flavus, in vitro, and are awaiting field testing. New and improved risk assessment models have been developed for sampling and measuring aflatoxin contamination through the processing stream and in bulk shipping lots of tree nuts. An automated sorter that detects and removes aflatoxin contaminated nuts from a processing stream in real time was developed. It was also concluded that methods currently used for hand‐cracking of closed shell pistachios result in a higher risk of aflatoxin contamination. Perhaps the foremost breakthrough to date, however, is that constituents of walnut seed coat, especially from the cultivar ‘Tulare’, are
{"title":"Current Research on Reducing Pre‐ and Post‐harvest Aflatoxin Contamination of U.S. Almond, Pistachio, and Walnut","authors":"B. Campbell, R. Molyneux, T. Schatzki","doi":"10.1081/TXR-120024093","DOIUrl":"https://doi.org/10.1081/TXR-120024093","url":null,"abstract":"Aflatoxins are considered to be potent carcinogens and teratogens to humans and farm animals. A variety of species of the fungal genus Aspergillus (mainly A. flavus and A. parasiticus) synthesize aflatoxins. Spores of these fungi are common in air and soil of agricultural areas of temperate and tropical environments. Because aflatoxigenic fungi are ubiquitous and opportunistic, aflatoxin contamination has become a food safety concern. The chief U.S. crops affected by the threat of contamination with aflatoxin include corn, peanuts, cottonseed, and certain tree nuts. Additionally, aflatoxin contamination has also become an international trade issue. Major trading partners of U.S. agricultural products have set total aflatoxin action threshold levels at four ng/g (ppb). This action level is far below the 20 ppb level recommended by the U.S. Food and Drug administration for domestic foods. Almonds, pistachios and walnuts are one of the major food commodities affected by food safety and trade issues associated with aflatoxin contamination. Commercial domestic production of these tree nuts in the U.S. is entirely in California. Moreover, 50 to 75% of domestically produced tree nuts are exported, chiefly to countries of the European Union (EU), which adhere to the four ppb action threshold level. Scientists at the USDA's Western Regional Research Center and the University of California, Davis' Department of Pomology and Kearney Agricultural Center have developed products and methods to reduce aflatoxin contamination of tree nuts. Control of insect pests in tree nut orchards is a major strategy to curtail aflatoxin contamination. Insect feeding damage can lead to fungal infection and concomitant aflatoxin contamination. This is especially the case with navel orangeworm on pistachio and almond. A new and potent lure has been developed to control codling moth, a major insect pest of walnuts whose feeding damage potentially leads to fungal infection. Through breeding and genetic engineering, new varieties of almonds and walnuts have been developed which are resistant to insect attack. New orchard management strategies have been prescribed to reduce reservoirs of A. flavus in tree nut orchards. A number of saprophytic yeasts, natural to tree nut orchards, have been discovered which show promise as biological control agents of A. flavus, in vitro, and are awaiting field testing. New and improved risk assessment models have been developed for sampling and measuring aflatoxin contamination through the processing stream and in bulk shipping lots of tree nuts. An automated sorter that detects and removes aflatoxin contaminated nuts from a processing stream in real time was developed. It was also concluded that methods currently used for hand‐cracking of closed shell pistachios result in a higher risk of aflatoxin contamination. Perhaps the foremost breakthrough to date, however, is that constituents of walnut seed coat, especially from the cultivar ‘Tulare’, are","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81303381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Nakajima, H. Naoki, G. Corzo, Dai-Zong Li, M. Hisada, P. Escoubas, N. Yamaji, H. Nagai, A. Yasuda, Marta Andrianstiferana, J. Haupt, Naomasa Ohshiro
Many kinds of venomous principles modulate physiological responses of mammalian signal transduction systems, on which they act selectively as enhancers, inhibitors or some other kind of effectors. These toxins have become useful tools for physiological research. We have characterized paralyzing toxins from the venom of spiders, scorpions, insects, jellyfishes and sea anemones in the subtropical region including the Ryukyu Islands. Venom profiles are screened by MALDI‐TOF fingerprinting analysis prior to purification of the venomous components, then marked target toxins of small molecular mass (1000–5000) are characterized directly by means of mass spectrometric techniques such as Frit‐FAB MS/MS, PSD/CID‐TOF MS, Capil. ‐HPLC/Q‐TOF MS/MS etc. The proteinous toxins of jellyfish or sea anemone are characterized by RT‐PCR technique by the information of the cleaved peptides after the protein was hydrolyzed by appropriate peptidase and the sequence of the cleaved peptide was determined by conventional methods. The venom of Araneid spider is mainly composed of a mixture of closely related acylpolyamines. More than 90 polyamine toxins were identified from one venom sac of the Madagascan spider, Nephilengys borbonica, by Frit‐Fab MS/MS employing charge remote fragmentation technique. A novel polyamine toxin was also found from the rare wondering spider, Macrothele gigas from Iriomote Island. The structure of the toxin is an analog of polyamine toxin found in trapdoor spiders. Many kinds of cystine‐rich peptides showing various types of ion channel antagonism have been isolated from spiders. A series of toxins possessing the same mode of cystine knots was recently isolated from the saliva of assassin bugs, Peirates turpis, Isyndus obscurus, Agriophodrus dohrni. These toxins act as calcium channel blocker. Most of the scorpion toxins reported are from scorpions hazardous to humans, and they belong to the major super family Buthoidea. Among them are the well‐known genera, such as Buthus, Androctonus, Centruroides, Leiurus, or Tytius. We have investigated the minor group of scorpions from the super family Chactoidea (Scorpionidae, Ishnuridae). The venoms of these scorpions, involving the genera Heterometrus, Pandinus, Opisthacanthus, and Isometrus, contain different kinds of peptide toxins. Fingerprinting peptide analysis of the toxin profiles for these scorpions showed some difference from the profiles of Buthoidea scorpions. These venoms contain linear pore‐forming peptides and 2‐cystine‐bridged toxins in addition to 4‐cystine‐bridged toxins. The most hazardous jellyfish in Okinawa, Chiropsalmus quadrigatus, and the related box jellyfishes, Carybdea rastoni, C. alata, contain quite labile proteinaceous toxins, CqTX, CrTX and CaTX, respectively. The toxins were inactivated by adding an organic solvent such as methanol or acetonitrile, by changing the pH of the toxin solution, dialyzing the toxin solution, storing the toxin in a refrigerator, or by lyophilizi
{"title":"A Trial of Mass Spectrometric Characterization of Femto‐Molar Amount from Subtropical Islands","authors":"T. Nakajima, H. Naoki, G. Corzo, Dai-Zong Li, M. Hisada, P. Escoubas, N. Yamaji, H. Nagai, A. Yasuda, Marta Andrianstiferana, J. Haupt, Naomasa Ohshiro","doi":"10.1081/TXR-120026910","DOIUrl":"https://doi.org/10.1081/TXR-120026910","url":null,"abstract":"Many kinds of venomous principles modulate physiological responses of mammalian signal transduction systems, on which they act selectively as enhancers, inhibitors or some other kind of effectors. These toxins have become useful tools for physiological research. We have characterized paralyzing toxins from the venom of spiders, scorpions, insects, jellyfishes and sea anemones in the subtropical region including the Ryukyu Islands. Venom profiles are screened by MALDI‐TOF fingerprinting analysis prior to purification of the venomous components, then marked target toxins of small molecular mass (1000–5000) are characterized directly by means of mass spectrometric techniques such as Frit‐FAB MS/MS, PSD/CID‐TOF MS, Capil. ‐HPLC/Q‐TOF MS/MS etc. The proteinous toxins of jellyfish or sea anemone are characterized by RT‐PCR technique by the information of the cleaved peptides after the protein was hydrolyzed by appropriate peptidase and the sequence of the cleaved peptide was determined by conventional methods. The venom of Araneid spider is mainly composed of a mixture of closely related acylpolyamines. More than 90 polyamine toxins were identified from one venom sac of the Madagascan spider, Nephilengys borbonica, by Frit‐Fab MS/MS employing charge remote fragmentation technique. A novel polyamine toxin was also found from the rare wondering spider, Macrothele gigas from Iriomote Island. The structure of the toxin is an analog of polyamine toxin found in trapdoor spiders. Many kinds of cystine‐rich peptides showing various types of ion channel antagonism have been isolated from spiders. A series of toxins possessing the same mode of cystine knots was recently isolated from the saliva of assassin bugs, Peirates turpis, Isyndus obscurus, Agriophodrus dohrni. These toxins act as calcium channel blocker. Most of the scorpion toxins reported are from scorpions hazardous to humans, and they belong to the major super family Buthoidea. Among them are the well‐known genera, such as Buthus, Androctonus, Centruroides, Leiurus, or Tytius. We have investigated the minor group of scorpions from the super family Chactoidea (Scorpionidae, Ishnuridae). The venoms of these scorpions, involving the genera Heterometrus, Pandinus, Opisthacanthus, and Isometrus, contain different kinds of peptide toxins. Fingerprinting peptide analysis of the toxin profiles for these scorpions showed some difference from the profiles of Buthoidea scorpions. These venoms contain linear pore‐forming peptides and 2‐cystine‐bridged toxins in addition to 4‐cystine‐bridged toxins. The most hazardous jellyfish in Okinawa, Chiropsalmus quadrigatus, and the related box jellyfishes, Carybdea rastoni, C. alata, contain quite labile proteinaceous toxins, CqTX, CrTX and CaTX, respectively. The toxins were inactivated by adding an organic solvent such as methanol or acetonitrile, by changing the pH of the toxin solution, dialyzing the toxin solution, storing the toxin in a refrigerator, or by lyophilizi","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89914294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Some health issues of marine toxins in Taiwan are introduced here. From 1986 to 2002, the causative agents of seafood poisoning incidents have been reported to be tetrodotoxin (TTX, 30 outbreaks), paralytic shellfish poisons (PSP, 3 outbreaks), grass carp bile toxins (sporadically), ciguateric toxins (about 1 outbreak per year), excess dose of vitamin A (2 outbreaks), histamine (more than 5 outbreaks), pyropheophorbide a (1 outbreak), fish roe of Ascrossochelius paradoxus (1 outbreak), and allergens (sporadically). Among them, health issue of TTX in Taiwan is the most concerned problem. Therefore, TTX‐containing animals have been found to include puffer, goby, xanthid crab, gastropod, starfish, and flatworm. The dried dressed fish fillets produced from the non‐toxic puffers have been found to be adulterated by toxic puffers. The SDS‐PAGE and PCR methods for identifying species of puffers and their products have been developed. PSP was distributed in the purple clam, xanthid crab, and gastropod in Taiwan. The toxic alga Alexandrium minutum appeared in December–March. The toxin production of alga was affected by a variety of nutritional, environmental, and physiological factors. Most shellfish possessed high resistance to PSP, but the susceptibility of shellfish to the toxic alga was quite different depending on species. The food safety of animal bile juice is another important issue in Taiwan. The toxicity of bile juice was in the order of grass carp ≫ chicken ≫ snake. The major component of grass carp bile powder was 5α‐cyprinol sulfate (more than 90%) and those of other animals are bile salts. The toxic potencies of 5α‐cyprinol sulfate and 5α‐cyprinol induced acute kidney failure, but bile salts induced chronic liver dysfunction. Other marine toxins including diarrheic shellfish poisons (DSP), neurotoxic shellfish poisons (NSP), and amnesic shellfish poisons (ASP) are also very important from the health viewpoint in the world, though no poisonings due to those toxins have so far occurred in Taiwan.
{"title":"Research on Marine Toxins in Taiwan","authors":"D. Hwang","doi":"10.1081/TXR-120026920","DOIUrl":"https://doi.org/10.1081/TXR-120026920","url":null,"abstract":"Some health issues of marine toxins in Taiwan are introduced here. From 1986 to 2002, the causative agents of seafood poisoning incidents have been reported to be tetrodotoxin (TTX, 30 outbreaks), paralytic shellfish poisons (PSP, 3 outbreaks), grass carp bile toxins (sporadically), ciguateric toxins (about 1 outbreak per year), excess dose of vitamin A (2 outbreaks), histamine (more than 5 outbreaks), pyropheophorbide a (1 outbreak), fish roe of Ascrossochelius paradoxus (1 outbreak), and allergens (sporadically). Among them, health issue of TTX in Taiwan is the most concerned problem. Therefore, TTX‐containing animals have been found to include puffer, goby, xanthid crab, gastropod, starfish, and flatworm. The dried dressed fish fillets produced from the non‐toxic puffers have been found to be adulterated by toxic puffers. The SDS‐PAGE and PCR methods for identifying species of puffers and their products have been developed. PSP was distributed in the purple clam, xanthid crab, and gastropod in Taiwan. The toxic alga Alexandrium minutum appeared in December–March. The toxin production of alga was affected by a variety of nutritional, environmental, and physiological factors. Most shellfish possessed high resistance to PSP, but the susceptibility of shellfish to the toxic alga was quite different depending on species. The food safety of animal bile juice is another important issue in Taiwan. The toxicity of bile juice was in the order of grass carp ≫ chicken ≫ snake. The major component of grass carp bile powder was 5α‐cyprinol sulfate (more than 90%) and those of other animals are bile salts. The toxic potencies of 5α‐cyprinol sulfate and 5α‐cyprinol induced acute kidney failure, but bile salts induced chronic liver dysfunction. Other marine toxins including diarrheic shellfish poisons (DSP), neurotoxic shellfish poisons (NSP), and amnesic shellfish poisons (ASP) are also very important from the health viewpoint in the world, though no poisonings due to those toxins have so far occurred in Taiwan.","PeriodicalId":17561,"journal":{"name":"Journal of Toxicology-toxin Reviews","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74935212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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