Natural toxins最新文献_第5页

High performance liquid chromatography coupled with post-column electrochemical oxidation for the detection of PSP toxins. 高效液相色谱-柱后电化学氧化法检测PSP毒素。

Natural toxins Pub Date : 1999-01-01 DOI: 10.1002/1522-7189(199911/12)7:6<353::aid-nt83>3.0.co;2-d

G L Boyer, G D Goddard

{"title":"High performance liquid chromatography coupled with post-column electrochemical oxidation for the detection of PSP toxins.","authors":"G L Boyer, G D Goddard","doi":"10.1002/1522-7189(199911/12)7:6<353::aid-nt83>3.0.co;2-d","DOIUrl":"https://doi.org/10.1002/1522-7189(199911/12)7:6<353::aid-nt83>3.0.co;2-d","url":null,"abstract":"High Performance Liquid Chromatography (HPLC) is an important tool for the study of PSP toxins. It provides an alternative to bioassays and gives the concentration of individual toxin isomers. The current HPLC protocol uses a post-column chemical reaction system (PCRS) to oxidize the saxitoxin ring system to form a fluorescent chromophore. This oxidation is sensitive to changes in the flow rate, temperature, pH and age of the reagents. We have previously shown that this oxidation can be accomplished using electrochemical techniques. Termed the electrochemical oxidation system (ECOS), this approach provides a simpler alternative to the traditional PCRS-based HPLC system. A detailed description of the construction and maintenance of an HPLC-ECOS system for the analysis of PSP toxins is presented. Comparisons of the mouse bioassay, HPLC-PCRS and HPLC-ECOS system are presented for three different sample matrices: toxic dinoflagellates (Alexandrium tamarense), geoduck (Panopea generosa) and scallops (Placopectin magellanicus). In all three cases, the correlation of the HPLC-ECOS system to the mouse bioassay is similar to that obtained using the HPLC-PCRS system for the analysis of PSP toxins.","PeriodicalId":18777,"journal":{"name":"Natural toxins","volume":"7 6","pages":"353-9"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1522-7189(199911/12)7:6<353::aid-nt83>3.0.co;2-d","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21946555","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}

引用次数: 16

Complexation and ionophoric properties of taxol and colchicine: complex formation and transport of sodium, potassium, magnesium and calcium ions across a liquid membrane. 紫杉醇和秋水仙碱的络合和离子亲和性:钠、钾、镁和钙离子在液体膜上的络合形成和运输。

Natural toxins Pub Date : 1999-01-01 DOI: 10.1002/1522-7189(200009/10)7:5<179::aid-nt57>3.0.co;2-#

M Blaghen, N Lahlou, F Z Dzairi, A Moutaouakkil, M Talbi

{"title":"Complexation and ionophoric properties of taxol and colchicine: complex formation and transport of sodium, potassium, magnesium and calcium ions across a liquid membrane.","authors":"M Blaghen, N Lahlou, F Z Dzairi, A Moutaouakkil, M Talbi","doi":"10.1002/1522-7189(200009/10)7:5<179::aid-nt57>3.0.co;2-#","DOIUrl":"https://doi.org/10.1002/1522-7189(200009/10)7:5<179::aid-nt57>3.0.co;2-#","url":null,"abstract":"We report the activities of taxol (an anticancer drug) and colchicine, which are inhibitors of microtubule organization, on the complexation and transport of Na+, K+, Mg2+ and Ca2+ ions across a liquid membrane, using a spectrophotometric procedure. Taxol, a diterpenoid compound, that has been demonstrated to possess a potent antitumour activity, is shown to extract Na+, K+, Mg2+ and Ca2+ ions from the aqueous solution to the organic phase with preference for Ca2+ ions. A kinetic study of the transport and complexation of Na+, K+, Mg2+ and Ca2+ ions through a liquid membrane revealed that the K+ ion is more rapidly transported and the Ca2+ ion is more rapidly complexed than other ions. However, colchicine, another alkaloid compound, extracted and transported only the divalent ions tested, Mg2+ and Ca2+. In both complexation and transport, the flux of the ions increases with the concentration of taxol or colchicine. Complexation and ionophoric properties of taxol and colchicine sheds new lights on therapeutic properties of these drugs. The treatment of disease states by the administration of these drugs to alter membrane permeability will prove to be a valuable therapeutic concept.","PeriodicalId":18777,"journal":{"name":"Natural toxins","volume":"7 5","pages":"179-85"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1522-7189(200009/10)7:5<179::aid-nt57>3.0.co;2-#","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21783215","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}

引用次数: 2

Neuronal binding of tetanus toxin compared to its ganglioside binding fragment (H(c)). 与神经节苷脂结合片段相比，破伤风毒素的神经元结合(H(c))。

Natural toxins Pub Date : 1999-01-01

P S Fishman, D A Parks, A J Patwardhan, C C Matthews

{"title":"Neuronal binding of tetanus toxin compared to its ganglioside binding fragment (H(c)).","authors":"P S Fishman, D A Parks, A J Patwardhan, C C Matthews","doi":"","DOIUrl":"","url":null,"abstract":"The non-toxin 50 kD C-terminus peptide of the heavy chain of tetanus H(c) contains the ganglioside binding domain of tetanus toxin (TTX). H(c) retains much of the capacity of tetanus toxin for binding internalization and transport by neurons. For this reason tetanus H(c) has been studied as a vector for delivery of therapeutic proteins to neurons. We directly compared H(c) and TTX in the capacity to bind and be internalized by neurons by ELISA. Primary cultures of dissociated fetal cortical neurons were incubated with equimolar amounts of TTX or H(c). Neuronal associated tetanus protein was 4-8 fold greater on a molar basis with tetanus toxin compared to H(c) (1 h incubation). This increase in neuronal tetanus protein was evident with incubation in concentrations from 0.1 microM to 2 microM. There were greater amounts of TTX delivered to the cultured cells at both 0 degrees C (representing membrane bound tetanus protein) and 37 degrees C (bound and internalized tetanus protein). Unlike H(c), TTX showed significant continued accumulation of protein with increasing incubation durations. Neuronal associated TTX increased 2-3 fold over incubation times ranging from 1 to 8 h. Tetanus toxin appears to be clearly superior to the ganglioside binding fragment (H(c)) in the capacity for neuronal binding and internalization. Atoxic tetanus proteins containing additional molecular domains as well as H(c) may be more suitable vectors for linkage with therapeutic proteins and delivery to neurons.","PeriodicalId":18777,"journal":{"name":"Natural toxins","volume":"7 4","pages":"151-6"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21644810","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}

引用次数: 0

Alteration in sphingolipid metabolism: bioassays for fumonisin- and ISP-I-like activity in tissues, cells and other matrices. 鞘脂代谢的改变:组织、细胞和其他基质中伏马菌素和isp - i样活性的生物测定。

Natural toxins Pub Date : 1999-01-01 DOI: 10.1002/1522-7189(199911/12)7:6<407::aid-nt84>3.0.co;2-0

R T Riley, W P Norred, E Wang, A H Merrill

{"title":"Alteration in sphingolipid metabolism: bioassays for fumonisin- and ISP-I-like activity in tissues, cells and other matrices.","authors":"R T Riley, W P Norred, E Wang, A H Merrill","doi":"10.1002/1522-7189(199911/12)7:6<407::aid-nt84>3.0.co;2-0","DOIUrl":"https://doi.org/10.1002/1522-7189(199911/12)7:6<407::aid-nt84>3.0.co;2-0","url":null,"abstract":"The first discovered naturally occurring inhibitor of de novo sphingolipid biosynthesis was fumonisin B1. There are now 11 identified fungal inhibitors of ceramide synthase or 'fumonisin B1-like' compounds. With the exception of the australifungins, all other fungal ceramide synthase inhibitors are structurally sphingoid-like. There are several recently discovered fungal inhibitors of another enzyme in the de novo sphingolipid biosynthesis pathway: serine palmitoyltransferase (SPT). One of the SPT inhibitors is named ISP-I. While ceramide synthase inhibitors are toxic to animals, plants and fungi, the SPT inhibitors are not known to cause animal or plant disease, but are potent inhibitors of fungal growth. Very little is known about their toxicity in animals. There are at least 24 fungal SPT inhibitors produced by a variety of fungi. Given that the fungal inhibitors of sphingolipid biosynthesis are chemically and biologically diverse, two bioassays have been developed to screen for fumonisin-like or ISP-I-like activity in naturally contaminated products or fungal culture materials. These bioassays are based on the changes in free sphingoid base concentration that occur when the ceramide synthase or SPT are inhibited. The bioassays have the advantage that they are functionally rather than chemically specific and thus will detect ceramide synthase and SPT inhibitors regardless of their chemical structure.","PeriodicalId":18777,"journal":{"name":"Natural toxins","volume":"7 6","pages":"407-14"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1522-7189(199911/12)7:6<407::aid-nt84>3.0.co;2-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21945392","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}

引用次数: 34

The lichen rock tripe (Lasallia pustulata) as survival food: effects on growth, metabolism and immune function in Balb/c mice. 生存食物地衣岩肚对Balb/c小鼠生长、代谢和免疫功能的影响。

Natural toxins Pub Date : 1999-01-01 DOI: 10.1002/1522-7189(199911/12)7:6<321::aid-nt90>3.0.co;2-u

N G Ilbäck, S Källman

{"title":"The lichen rock tripe (Lasallia pustulata) as survival food: effects on growth, metabolism and immune function in Balb/c mice.","authors":"N G Ilbäck, S Källman","doi":"10.1002/1522-7189(199911/12)7:6<321::aid-nt90>3.0.co;2-u","DOIUrl":"https://doi.org/10.1002/1522-7189(199911/12)7:6<321::aid-nt90>3.0.co;2-u","url":null,"abstract":"The present study was performed to investigate whether the lichen rock tripe (Lasallia pustulata) can be used as food during survival situations. The effects of 30% lichen supplementation given to female Balb/c mice were studied on growth rate, metabolism and immune functions. After 3 weeks on this diet, it was found that the lichen supplementation did not affect the growth rate or the well-being of the animals. The growth rate tended to be higher in the lichen group when compared to control mice. Food consumption was similar in both groups, but with a trend towards slightly higher intake (12%) in the lichen group. The heart, liver, kidney and lymphoid organ (spleen and thymus) weights were not affected by the lichen. Histological hematoxylin eosin staining showed that all these organs were normal. Plasma glucose levels were unchanged, but plasma urea levels decreased by 24% (p < 0.05) with the lichen diet. Red and white blood cells and the number of lymphoid cells in the thymus and spleen were normal. The activity of thymocytes and spleen T-lymphocytes were not affected by the lichen diet, but spontaneous cell-mediated cytotoxicity (NK cells) tended (n.s.) to increase and spleen B-lymphocyte activity increased by 40% (p < 0.05). This study shows that the lichen rock tripe has immune stimulating effects important for host defence reactions and can be used as food in survival situations without any adverse effects on the metabolism.","PeriodicalId":18777,"journal":{"name":"Natural toxins","volume":"7 6","pages":"321-9"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1522-7189(199911/12)7:6<321::aid-nt90>3.0.co;2-u","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21946066","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}

引用次数: 0

A receptor binding assay for paralytic shellfish poisoning toxins: recent advances and applications. 麻痹性贝类中毒毒素的受体结合试验:最新进展及应用。

Natural toxins Pub Date : 1999-01-01 DOI: 10.1002/1522-7189(199911/12)7:6<393::aid-nt82>3.0.co;2-c

C L Powell, G J Doucette

{"title":"A receptor binding assay for paralytic shellfish poisoning toxins: recent advances and applications.","authors":"C L Powell, G J Doucette","doi":"10.1002/1522-7189(199911/12)7:6<393::aid-nt82>3.0.co;2-c","DOIUrl":"https://doi.org/10.1002/1522-7189(199911/12)7:6<393::aid-nt82>3.0.co;2-c","url":null,"abstract":"We recently described a high throughput receptor binding assay for paralytic shellfish poisoning (PSP) toxins, the use of the assay for detecting toxic activity in shellfish and algal extracts, and the validation of 11-[3H]-tetrodotoxin as an alternative radioligand to the [3H]-saxitoxin conventionally employed in the assay. Here, we report a dramatic increase in assay efficiency through application of microplate scintillation technology, resulting in an assay turn around time of 4 h. Efforts are now focused on demonstrating the range of applications for which this receptor assay can provide data comparable to the more time consuming, technically demanding HPLC analysis of PSP toxins, currently the method of choice for researchers. To date, we have compared the results of both methods for a variety of sample types, including different genera of PSP toxin producing dinoflagellates (e.g. Alexandrium lusitanicum, r2 = 0.9834, n = 12), size-fractioned field samples of Alexandrium spp. (20-64 microm; r2 = 0.9997, n = 10) as well as its associated zooplankton grazer community (200-500 microm: r2 = 0.6169, n = 10; >500 microm: r2 = 0.5063, n = 10), and contaminated human fluids (r2 = 0.9661, n = 7) from a PSP outbreak. Receptor-based STX equivalent values for all but the zooplankton samples were highly correlated and exhibited close quantitative agreement with those produced by HPLC. While the PSP receptor binding assay does not provide information on toxin composition obtainable by HPLC, it does represent a robust and reliable means of rapidly assessing PSP-like toxicity in laboratory and field samples. Moreover, this assay should be effective as a screening tool for use by public health officials in responding to suspected cases of PSP intoxication.","PeriodicalId":18777,"journal":{"name":"Natural toxins","volume":"7 6","pages":"393-400"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1522-7189(199911/12)7:6<393::aid-nt82>3.0.co;2-c","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21946562","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}

引用次数: 41

Silage and animal health. 青贮饲料与动物健康。

Natural toxins Pub Date : 1999-01-01 DOI: 10.1002/1522-7189(199911/12)7:6<221::aid-nt76>3.0.co;2-h

J M Wilkinson

{"title":"Silage and animal health.","authors":"J M Wilkinson","doi":"10.1002/1522-7189(199911/12)7:6<221::aid-nt76>3.0.co;2-h","DOIUrl":"https://doi.org/10.1002/1522-7189(199911/12)7:6<221::aid-nt76>3.0.co;2-h","url":null,"abstract":"The process of preserving crops by fermentation in silos is under the control of the farmer to a much lesser degree compared to the level of control by the manufacturer over the production of other fermented foods, such as cheese and yoghurt. Additives designed to direct the extent and pattern of the fermentation are relatively unpopular in most countries, and their use is not guaranteed to remove the risk of undesirable components in silage. Hazards to animal health associated with silage fall into three categories: (1) undesirable micro-organisms e.g. Listeria, enterobacteria, clostridia and moulds; (2) undesirable chemicals, e.g. mycotoxins, and (3) excess acidity and other metabolic disorders. In some regions of Europe, the production of silage is discouraged or prohibited because of the risk of undesirable microbes. The princIpal risk in these areas is that of the secondary fermentation of cheese made from milk contaminated by bacterial spores, rather than a direct hazard of contaminated silage to animal health. With the possible exception of high dry matter silage conserved in large bales, respiratory hazards to animals from moulds and their spores generally are less from silage than hay. Mycotoxins and phytoestrogens may survive the ensiling period and constitute risks to animal health. Relatively little is known about the epidemiology of diseases that may be linked to undesirable chemicals and excess acidity in silage. Therefore, research is needed to define epidemiologically and mechanistically the risks to animal health and to the human food chain from silages contaminated with pathogenic bacteria and mycotoxins, and to understand more completely the relationships between the physical and chemical compositions of silage and metabolic disorders in animals.","PeriodicalId":18777,"journal":{"name":"Natural toxins","volume":"7 6","pages":"221-32"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/1522-7189(199911/12)7:6<221::aid-nt76>3.0.co;2-h","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21944403","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}

引用次数: 89

Fluorometric analysis of pectenotoxin-2 in microalgal samples by high performance liquid chromatography. 微藻样品中果皮毒素-2的高效液相色谱荧光分析。

Natural toxins Pub Date : 1999-01-01 DOI: 10.1002/1522-7189(199911/12)7:6<241::aid-nt66>3.0.co;2-g

K Sasaki, A Takizawa, A Tubaro, L Sidari, R D Loggia, T Yasumoto

引用次数: 20

A review of the volatile metabolites of fungi found on wood substrates. 木质基质真菌挥发性代谢物的研究进展。

Natural toxins Pub Date : 1999-01-01 DOI: 10.1002/1522-7189(199911/12)7:6<283::aid-nt70>3.0.co;2-n

B J McAfee, A Taylor

引用次数: 43

The fungal metabolite culmorin and related compounds. 真菌代谢产物霉毒素及其相关化合物。

Natural toxins Pub Date : 1999-01-01 DOI: 10.1002/1522-7189(199911/12)7:6<305::aid-nt72>3.0.co;2-g

P B Pedersen, J D Miller

引用次数: 28