bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transfer of ochratoxin a from lactating rats to their offspring: A short‐term study
Authors: Breitholtz‐Emanuelsson Anna , Palminger‐Hallén Ira , Wohlin Pär Ola , Oskarsson Agneta , Hult Karl , Olsen Monica 
Published: October 2006

AbstractA dose‐dependent transfer of ochratoxin A into the milk of lactating rats was found after a single oral dose of ochratoxin A, given in the dose levels of 10,50, and 250 μg ochratoxin A/kg body weight by gastric intubation. The milk/blood concentration ratio of ochratoxin A at 24 and 72 h was 0.4 and 0.7, respectively. A linear relationship was found between the concentration of ochratoxin A in the dam's milk and in the blood of the pups at 72 h, as well as in the dam's milk and in the kidneys of the pups. The pup blood/milk concentration ratio of ochratoxin A was approximately 6. At 72 h the sucklings had higher levels of ochratoxin A than their dams in both blood and kidneys. The results show that the concentration of ochratoxin A in milk can be used as an indicator of the continuously administered dose to the suckling. © 1992 Wiley‐Liss, Inc.
Production of a toxin stemphol by Stemphylium species
Authors: Solfrizzo Michele , Strange Richard N. , Sabia Cinzia , Visconti Angelo 
Published: October 2006

AbstractFive of 11 isolates of Stemphylium botryosum Wallr. from oilseed rape produced the phytotoxin stemphol when cultured on rice, with yields varying from 15.0 to 98.4 mg/kg, and three of them also produced the toxin on Czapek Dox (CD) liquid medium supplemented with cations (0.12–0.31 mg/L) and potato‐dextrose (PD) broth (0.37–1.47 mg/L). In liquid cultures about 95% of stemphol was found in the mycelium, and toxin production was slightly increased when cultures were exposed to near UV light rather than being grown in the dark. The LD50 concentrations for stemphol against isolated cells of oilseed rape and chickpea were 8.4 and 7.0 μM, respectively. One isolate of S. msjusculum (strain no. 135459) produced much greater amounts of stemphol, i.e., 22.8 mg/L, 535.3 mg/L, and 548 mg/kg when grown on CD, PD, and rice, respectively. Leaves of oilseed rape, artificially infected with S. majusculum and bearing lesions that occupied an average of 70% of the lamina contained 0.9 μg stemphol per gram dry weight of leaf tissue. © 1994 Wiley‐Liss, Inc.
Production of polyclonal antibodies for cyclopaldic acid, a major phytotoxic metabolite produced by the plant pathogen Seiridium cupressi
Authors: Sorbo Giovanni Del , Evidente Antonio , Scala Felice 
Published: October 2006

AbstractAn antiserum against cyclopaldic acid (CA), a phytotoxic metabolite produced by Seiridium cupressi, the fungal pathogen of a canker disease of cypress, was prepared by immunization of rabbits with a CA‐bovine serum albumin conjugate (CA‐BSA). Antibodies recognizing CA were purified by affinity chromatography through an immunoadsorbent prepared by conjugating CA to lysine‐Sepharose 48. The specificity of antibodies was assayed against CA and some of its derivatives by competitive indirect enzyme‐linked immunoassay. The homologous antigen CA‐BSA and CA showed the highest binding activity with antibodies. The derivatives of CA modified in 1 of the 2 aldehyde groups reacted with antibodies to a lesser extent compared with CA‐BSA and CA. Isocyclopaldic acid and the tetraacetylderivative of CA, which have more than one modified functional group, showed a further decrease in their reactivity. Other derivatives, which have more substantial structural modifications of the carbon skeleton, did not react. The possible use of these antibodies in studies concerning the involvement of CA in the canker disease of cypress is discussed. © 1994 Wiley‐Liss, Inc.
Isolation and purification procedures for the preparation of paralytic shellfish poisoning toxin standards
Authors: Laycock Maurice V. , Thibault Pierre , Ayer Stephen W. , Walter John A. 
Published: October 2006

AbstractParalytic shellfish poisoning (PSP) is caused by mixtures of saxitoxin analoss of which more than eighteen are known. Reliable and sensitive analytical methods and assays for these toxins are essential to protect the consumer and the shellfish industry, but research has been restricted by a shortage of the pure compounds. Only saxitoxin has so far been generally available as a PSP toxin standard, yet sulfated analogs usually occur in higher concentrations than saxitoxin in toxic marine algae and shellfish. Methods are described for the purification of some of the common PSP toxins, in quantities sufficient for the preparation of PSP standards from the dinoflagellate Alexandrium excavatum, the giant sea scallop (Placopecten megallanicus) hepatopancreas, and the cyanobacterium Aphanizomenon flos‐aquae. Purity was monitored by high performance liquid chromatography with fluorescence detection (HPLC‐FD), ionspray mass spectrometry (ISP‐MS), capillary electrophoresis (CE), and proton NMR spectroscopy. Published 1994 Wiley‐Liss, Inc.
Development of rapid and sensitive high throughput pharmacologic assays for marine phycotoxins
Authors: van Dolah F. M. , Finley E. L , Haynes B. L. , Doucette G. J. , Moeller P. D. , Ramsdell J. S. 
Published: October 2006

AbstractThe lack of rapid, high throughput assays is a major obstacle to many aspects of research on marine phycotoxins. Here we describe the application of microplate scintillation technology to develop high throughput assays for several classes of marine phycotoxin based on their differential pharmacologic actions. High throughput “drug discovery” format microplate receptor binding assays developed for brevetoxins/ ciguatoxins and for domoic acid are described. Analysis for brevetoxins/ciguatoxins is carried out by binding competition with [3H] PbTx‐3 for site 5 on the voltage dependent sodium channel in rat brain synaptosomes. Analysis of domoic acid is based on binding competition with [3H] kainic acid for the kainate/quisqualate glutamate receptor using frog brain synaptosomes. In addition, a high throughput microplate 45Ca flux assay for determination of maitotoxins is described. These microplate assays can be completed within 3 hours, have sensitivities of less than 1 ng, and can analyze dozens of samples simultaneously. The assays have been demonstrated to be useful for assessing algal toxicity and for assay‐guided purification of toxins, and are applicable to the detection of biotoxins in seafood. © 1994 Wiley‐Liss, Inc.
Toxic effect of the bloom‐forming Trichodesmium sp. (cyanophyta) to the copepod Acartia tonsa
Authors: Guo Chunzhi , Tester Patricia A. 
Published: October 2006

AbstractThe toxicity of the marine cyanobacterium Trichodesmium sp. to the copepod Acartia tonsa was assessed in a series of experiments during a Trichodesmium bloom off the North Carolina coast in late October 1992. Healthy intact cells of Trichodesmium sp. were not toxic to A. tonsa and were ingested by A tonsa when no other foods were available. However, homogenized Trichodesmium cells were toxic to A. tonsa, suggesting that Trichodesmium sp. contains certain type(s) of intracellular biotoxins. This hypothesis was consistent with the observed high mortality when A. tonsa was treated with aging Trichodesmium sp. cells or with filtered cell homogenate. The affected copepods showed weakness, recumbency, and reduced responsiveness. Many were observed to have distended intestines. Bioassays using aged Trichodesmium sp. cells and filtered homogenate demonstrated a dose‐dependent effect on A. tonsa survival. © 1994 Wiley‐Liss, Inc.
An incident of elevated levels of unsaturated free fatty acids in mussels from Nova Scotia and their toxic effect in mice after intraperitoneal injection
Authors: Lawrence James F. , Chadha Rajinder K. , Ratnayake W. M. Nimal , Truelove John F. 
Published: October 2006

AbstractMethanol extracts of the hepatopancreas of mussels (Mytilus edulis) harvested at two locations (Ship Harbour and Wine Harbour) in eastern Nova Scotia, Canada, were found to be toxic to mice after intraperitoneal injection. The commonly known toxins, such as those associated with diarrhetic shellfish poison (DSP), paralytic shellfish poison, and domoic acid, were not present in the extracts. However, they were found to contain elevated levels of free fatty acids. Using a modified DSP extraction procedure the quantities of free fatty acids determined (by latroscan TLC/FID) in the hepatopancreases of mussels were 2.9 mg/g (Ship Harbour 1), 2.2 mg/g (Ship Harbour 2), 1.2 mg/g (Wine Harbour), and 0.15 mg/g (Prince Edward Island, control). After further investigation it was determined that certain unsaturated fatty acids were mainly responsible for the toxicity. These included palmitoleic, linoleic, linolenic, octadecatetraenoic, and eicosapentenoic acids. Artificial mixtures of pure standards of these acids prepared in the same concentrations as found in the shellfish samples were also toxic to mice. These results indicate that elevated levels of free fatty acids in mussel hepatopancreas from locations in eastern Canada can lead to mouse deaths when using the DSP mouse bioassay procedure. © 1994 wiley‐Liss, Inc.
Bracken fern (Pteridium spp.) carcinogenicity and human health—a brief review
Authors: Smith Barry L. , Seawright Alan A. 
Published: October 2006

AbstractBracken fem (Pteridium spp.), one of the most abundant plants on the planet, is well known to cause cancer naturally in sheep and cattle. It contains, in some locations, extremely high concentrations of ptaquiloside which almost certainly is its major carcinogen. Ptaquiloside is transferred through milk. There is epidemiological evidence that the bracken carcinogen, in special situations, may cause cancer in man. Ptaquiloside and its animal models of carcinogenesis also offer good tools for the study of cancer. © 1995 Wiley‐Liss, Inc.
Purification and characterization of myotoxin IV, a phospholipase A2 variant, from Bothrops asper snake venom
Authors: Diaz Cecilia , Lomonte Bruno , Zamudio Fernando , Gutiérrez José María 
Published: October 2006

AbstractA basic myotoxic protein was purified from Bothrops asper venom. Like other basic Bothrops myotoxins, myotoxin IV induces acute muscle damage after intramuscular injection in mice and disrupts negatively charged liposomes but not positively charged ones. Furthermore, this protein exerts a weak anticoagulant effect only at concentrations of 40 μg/ml or higher, and is devoid of phospholipase A2 activity. Rabbit polyclonal antibodies to B. asper myotoxin II, a related lysine‐49 isoform, cross‐react strongly with myotoxin IV by enzyme immunoassay, indicating a high degree of antigenic similarity between these two proteins. The fact that both toxins have similar amino acid compositions and amino‐terminal sequences, including leucine‐5 and glutamine‐11, 2 amino acid residues conserved in all lysine‐49 phospholipase A2 variants purified, strongly suggests that B. asper myotoxin IV is a lysine‐49 phospholipase A2. © 1995 Wiley‐Liss, Inc.
Isolation and characterization of microcystins from laboratory cultures and environmental samples of Microcystis aeruginosa and from an associated animal toxicosis
Authors: Lawton Linda A. , Edwards Christine , Beattie Kenneth A. , Pleasance Stephen , Dear Gordon J. , Codd Geoffrey A. 
Published: October 2006

AbstractSix microcystins were identified in a laboratory culture of the cyanobacterium (blue‐sreen alga) Microcystis aeruginosa PCC 7813 using high‐performance liquid chromatography coupled with diode array detection (HPLG‐DAD) and mass spectrometry (LC‐MS). The toxins were purified and further characterized by amino acid analysis and tandem mass spectrometry (MS‐MS). The presence of the previously reported microcystin‐LR and microcystinly was confirmed. Two further microcystins were characterized as microcystin‐LW and microcystin‐LF. Another two toxins were partially characterized and are believed to be an analog of microcystin‐LR (molecular weight 1008) and microcystin‐LM (molecular weight 969). Natural bloom material of M. aeruginosa collected from 2 reservoirs was found to have similar microcystin profiles using HPLC‐DAD and LC‐MS, indicating the widespread occurrence of these microcystin variants. In addition, the presence of 5 of the microcystins was confirmed in the rumen contents of a lamb by LC‐MS and LC‐MS‐MS, providing the first report of microcystins identified in an animal suspected of being poisoned by cyanobacterial hepatotoxins. © 1995 Wiley‐Liss, Inc.
Novel monoclonal antibodies against microcystin and their protective activity for hepatotoxicity
Authors: Nagata Satoshi , Soutome Hiroshi , Tsutsumi Tomoaki , Hasegawa Akihiro , Sekijima Masaru , Sugamata Masao , Harada Ken‐Ichi , Suganuma Masami , Ueno Yoshio 
Published: October 2006

AbstractSix monoclonal antibodies (MAbs) to microcystin‐LR (MCLR), a cyclic heptapeptide hepatotoxin isolated from the cyanobacterium Microcystis aeruginosa, were produced. They showed the protective effects on hepatotoxicity of MCLR in vitro and in vivo, and on the inhibition of protein phosphatase by MCLR. Competitive enzyme‐linked immunosorbent assays with various microcystins revealed that the six MAbs recognized a part of the molecule, in particular, a tertial structure around Adda, 3‐amino‐9‐methoxy‐2,6,8‐trimethyl‐10‐phenyldeca‐4,6‐dienoic acid. The specificity of these MAbs varied slightly. In primary rat hepatocyte cultures, all MAbs showed protective effects against the MCLR‐induced cell damages, assessed by morphological changes, lactate dehydrogenase release into the medium, and a calorimetric assay to measure the cell viability using a tetrazolium dye. The M8H5 MAb showing the highest affinity for MCLR blocked the lethal effects and hepatocellular damage to mice. In addition, M8H5 MAb recovered protein phosphatase 2A inhibition by MCLR in a dose‐dependent manner, while phosphatase inhibition by okadaic acid was not affected. Thus, the MAbs specifically reacted with the microcystins and prevented their biological activities. This is the first report on the protective effects of specific monoclonal antibodies on MCLR‐induced toxicity. © 1995 Wiley‐Liss, Inc.
Fusaric acid in Fusarium moniliforme cultures, corn, and feeds toxic to livestock and the neurochemical effects in the brain and pineal gland of rats
Authors: Porter James K. , Bacon Charles W. , Wray Emma M. , Hagler Winston M. 
Published: October 2006

AbstractFusaric acid is produced by several species of Fusarium, which commonly infect corn and other agricultural commodities. Since this mycotoxin may augment the effects of other Fusarium toxins, a gas chromatography/mass spectrometry method of analysis in feeds was developed. Fusaric acid was analyzed as the trimethylsilyl‐ester from F. monilifotme‐cultures, ‐contaminated corn screenings, and feeds toxic to livestock. The mycotoxin was found in all samples and ranged from 0.43 to 12.39 μg/g sample. Also, fusaric acid was tested for its neurochemical effects in the brain and pineal gland of rats. Animals were dosed intraperitoneally (100 mg/kg body weight) 30 min prior to the onset of the dark phase (lights out) and the effects were studied at 1.5, 3.5, and 5.5 h after treatment. Brain serotonin (5HT), 5‐hydroxyindoleacetic acid (5HIAA), tyrosine (TYRO), and dopamine (DA) were increased (P < 0.05) by fusaric acid, and norepinephrine (NEpi) was decreased (P < 0.05). Analogously, DA in the pineal gland increased and NEpi decreased (P < 0.05). Pineal N‐acetylserotonin (NAcSHT) was increased (P < 0.05), whereas pineal 5HT and its two major metabolites 5HIAA and 5‐hydroxytrytophol (5HTOL) decreased (P < 0.05). Elevated brain TYRO and brain and pineal DA, with decreased NEpi, may be consistent with fusaric acid's partial inhibitory effect on tyrosine‐hydroxylase and its inhibitory effect on dopamine‐β‐hydroxylase, respectively. Elevated pineal Nac5HT is consistent with decreased pineal 5HT and the increased pineal DA, and support the dopaminergic stimulatory activity of the enzyme responsible for the conversion of 5HT to NAc5HT. This is the first report of fusaric acid's in vivo effect on pineal DA, NEpi, 5HT, and NAc5HT in rats, and a relation for the effects on TYRO, 5HT, and 5HIAA in brain tissue. The results indicate fusaric acid alters brain and pineal neurotransmitters and may contribute to the toxic effects of Fusarium‐contaminated feeds. © 1995 Wiley‐Liss, Inc.
Toxicokinetics of ochratoxin A in rat following intratracheal administration
Authors: Breitholtz‐Emanuelsson Anna , Fuchs Radovan , Hult Karl 
Published: October 2006

AbstractThe toxicokinetic parameters of ochratoxin A in rat following intratracheal administration of 50 ng ochratoxin A/g body weight were studied. The absorption of ochratoxin A from the lungs was very efficient. The elimination pattern of the toxin was studied by the analysis of blood samples. The biological half‐life of ochratoxin A was 127 h and the calculated apparent volume of distribution equalled 168 ml/kg. The bioavailability of the toxin was very high, 98%. The plasma clearance of the toxin was 0.92 ml/kg·h. © 1995 Wiley‐Liss, Inc.
Comparative pathology of microcystin‐lr in cultured hepatocytes, fibroblasts, and renal epithelial cells
Authors: Khan Safdar All , Ghosh Shushmita , Wickstrom Mark , Miller Lou Ann , Hess Rex , Haschek Wanda M. , Beasley Val R. 
Published: October 2006

AbstractThe cyanobacterial toxin microcystin‐LR (MCLR) is a potent inhibitor of protein phosphatases 1 and 2A, and is selectively toxic to the liver in vivo and to isolated hepatocytes in vitro. This selectivity is believed to be due to toxin uptake via bile acid carriers. We investigated at the light and ultrastructural levels the effects of high concentrations of MCLR and long incubation times to determine in vitro whether fibroblasts and kidney cells (non‐target cells) respond in the same manner as do hepatocytes (target cells) at low concentrations and short incubation times. Cultured rat skin fibroblasts (ATCC 1213) and rat kidney epithelial cells (ATCC 1571) were incubated with MCLR at 133 μM 1‐24 hr. Lesions in these cells were compared with those in cultured hepatocytes incubated with MCLR at 13.3 μM from 1 to 32 min. Lesions in hepatocytes, kidney cells, and fibroblasts were noted at 4 min, 1 hr, and 8 hr, respectively, after initial exposure to MCLR. Lesions in all three cell types progressed and included plasma membrane blebbing, loss of cell‐to‐cell contact, clumping and rounding of cells, cytoplasmic vacuolization, and redistribution of cytoplasmic organelles. Loss of microvilli, whorling of rough endoplasmic reticulum, dense staining and dilated cristae in mitochondria, and pinching off of membrane blebs were noted only in hepatocytes. Nuclear changes typical of apoptosis were observed only in fibroblasts and kidney cells. Similarities in responses of different cell types to MCLR exposure probably reflect a common biochemical mechanism of action, i.e., inhibition of protein phosphatases 1 and 2A as described by others. The observed differences in the responses of the cell types examined in this study may reflect differences in the proteins phosphorylated and the severity of hyperphosphorylation. © 1995 Wiley‐Liss, Inc.
Ion selectivity of the channels formed by pardaxin, an lonophore, in bilayer membranes
Authors: Shi Yu Liang , Edwards Charles , Lazarovici Philip 
Published: October 2006

AbstractUsing the method of bilayer membranes at the tip of a patch pipette, the properties of the ionic channels produced by the ionophore toxin pardaxin were investigated. At low toxin concentrations, voltage‐dependent, single‐channel events were measured. The current‐voltage curves were non‐linear when determined in Tris‐CI solution, but were linear in K+‐HEPES solution. Using asymmetric ion solutions, the ionic selectivity of pardaxin channels was estimated from the reversal potentials obtained. The sequence of the relative permeabilities for monovalent cations was Tl+ > Rb+ > Cs+ > K+,NH4+ > methylamine+ > Li+ > dimethylamine+ > Na+. Except for Li+, the selectivity sequence fitted the cations relative hydrated size. For bivalent ions the permeability of Ba2+, Sr2+, and Mn2+ relative to Mg2+ changed according to the relative hydrated size. For anions the selectivity sequence was I− > NO3− > Br− > CI− > CIO4− > SCN− > BF− > HCOO− > F− > CH3COO−. The selectivity sequence for the small anions (I−, NO3−, Br−, CI−) was different from their hydrated size. Pardaxin channel showed a modest ion selectivity between small anions and cations (PK:PCI:PNa = 1.28:1.00:0.56). Pardaxin is proposed as a biophysical model to study ionic channel selectivity. © 1995 Wiley‐Liss, Inc.
Biological activity of cyclopaldic acid, a major toxin of Seiridium cupressi, its six derivatives, and iso‐cyclopaldic acid
Authors: Sparapano Lorenzo , Evidente And Antonio 
Published: October 2006

AbstractCyclopaldic acid (CA), its six derivatives, and iso‐cyclopaldic acid (IsoCA) were assayed for toxicity to cuttings of three species of cypress, as well as to mung bean, oat, and tomato explants. Toxicity to host and non‐host plants of CA derivatives having one or both of the aldehyde groups transformed was less than that of CA. Shoot tissues of Cupressus macrocarpa artificially infected by Seiridium cupressi leached electrolytes more than those of C. sempervirens and C. arizonica. CA, IsoCA, and to a lesser extent the monoacetylated, phenylhydrazone and hydrogenated derivatives of CA caused loss of electrolytes from cypress tissures. CA, IsoCA, and monoacetyl CA caused limited callus development of cypress tissue. Diacetylhydrazone CA enhanced the yield of cypress callus tissue. CA derivatives having both aldehyde groups modified induced root formation on cypress cuttings. The antifungal activity showed by CA toward species of Botrytis, Fusarium, and Geotrichum markedly decreased in its derivatives. The inhibitory effect of CA on esterases was exhibited also by IsoCA and the monoacetylated derivative. © 1995 Wiley‐Liss, Inc.
Economic losses and decontamination
Authors: Charmley Lynne L. , Trenholm H. Locksley , Prelusky Dan B. , Rosenberg Alex 
Published: October 2006

AbstractMycotoxin contamination of crops may cause economic losses at all levels of food and feed production including crop and animal production, and crop distribution and processing. The national economy would be affected adversely by losses incurred by crop and livestock producers and the multiplier effect this has on other industries as a result of the reduced spending power of producers. Costs of chemical analyses, quality control and regulatory programs, research and development, extension services, law suits, and the cost of human illnesses must all be bome by the national economy. The value of the losses encountered depends on grain, animal, and animal product prices, interest rates, degree of contamination, and other economic variables. Even during favourable seasons it is likely that millions of dollars are lost as a result of the contamination of crops with mycotoxins.Many compounds and treatments have been tested in order to reduce mycotoxin concentrations in food and feed or to alleviate their adverse effects on animals. Some of these treatments show promising prospects for commercial application, while others have had commercial applications already. However, until reliable, cost‐effective, commercially applicable methods are more widely available, problems associated with mycotoxin contamination and the economic losses resulting, will continue to be seen in food and agriculture industries. Published 1995 Wiley‐Liss, Inc.