bluuebunny/crossref_metadata_2025 huggingface dataset:
Reading and navigational strategies of Web users with lower literacy skills
Authors: Summers Kathryn , Summers Michael
Published: October 2006

About half of the adults in the U.S. read at the 8th grade level or below (Kirsch, Junegeblut, Jenkins, & Kolstad, 1993). Yet most websites are written at the 10th grade level or higher. The goal of this two‐year study, sponsored by Pfizer, was twofold: 1) to understand the differences between the reading and navigational strategies of users with medium to high literacy skills and those with lower literacy skills; 2) to learn how to make web‐based medical content usable and accessible for lower‐literacy adults, and to develop design principles that could be used to design websites that would meet the needs of both higher and lower literacy users.
Conflicting approaches to user information seeking education in Scandinavian Web‐based tutorials
Authors: Sundin Olof
Published: October 2006

The purpose of this paper is to make visible different approaches to university librarians' professional expertise such as they are mediated through user information seeking education. The empirical basis of the study consists of an analysis of 31 web‐based tutorials in information literacy accessible via Scandinavian university libraries' web‐sites. The results make apparent four, sometimes conflicting, approaches to user information seeking education expressed in the tutorials: a source approach, a behavior approach, a process approach and a communication approach. These approaches disclose different ways of defining central concepts such as information, information seeking and the user. A study of attitudes to user education is important as attitudes entail practical consequences for the operation of user education.
Affective and cognitive information behavior: Interaction effects in Internet use
Authors: Nahl Diane
Published: October 2006

The presence and influence of affective variables in information behavior was studied. Affective load (AL), a compound variable consisting of uncertainty and technophobia measures, was found to be present in a variety of simple and complex information tasks integrated into upper‐division, disciplinary coursework. Affective load was higher in those who reported low values of affective coping skills and who had either high or low cognitive assessment scores. Affective coping skills (ACS) consist of self‐efficacy (SE) and optimism (Op) measures. High self‐efficacy and optimism have been found to significantly and beneficially influence success in a variety of information tasks, by counteracting the effects of negative emotions such as irritation and frustration. In this study, high coping skills provided a significant affective advantage as indicated by higher optimism, stronger self‐efficacy, lower uncertainty, higher support and acceptance of the system and lower affective load. The group with high cognitive skills reported significantly higher optimism, higher affective coping skills and higher felt exercise of control, demonstrating an interaction between cognitive and affective skills. There was a distinct advantage for those who had both high affective coping skills and high cognitive skills. They experienced relatively low affective load and high acceptance of the system.
Immunomodulatory effects of fusarochromanones TDP‐1 and TDP‐2
Authors: Minervini Fiorenza , Lucivero Giacomo , Visconti Angelo , Bottalico Clementina
Published: October 2006

An in vitro peripheral lymphocyte blastogenesis system was used to investigate the biological activities of the fungal toxin fusarochromanone (TDP‐1) and its monoacetyl derivative TDP‐2. Briefly, cultures of human or bovine peripheral lymphocytes were exposed to TDP‐1 or TDP‐2 and a mitogen (PHA, Con A or PWM). After a standard incubation time, cell proliferation was quantified using the MTT bioassay. Human and bovine lymphocyte proliferation was inhibited by high concentrations of TDP‐1; however, bovine lymphocyte proliferation was significantly increased at low concentrations of TDP‐1. TDP‐2 has similar but less pronounced effects on lymphocyte proliferation. © 1992 Wiley‐Liss, Inc.
Biological activities of Synanceja horrida (stonefish) venom
Authors: Khoo H. E. , Yuen R. , Poh C. H. , Tan C. H.
Published: October 2006

Some biological and neurochemical properties of the venom of stonefish (Syanceja horrida) were investigated. The venom exhibited oedema‐inducing, haemolytic, hyaluronidase, thrombin‐like, alkaline phosphomonoesterase, 5′ nucleotidase, acetylcholinesterase, phosphodiesterase, arginine esterase, and arginine amidase activities. Recalcification clotting time, prothrombin, and kaolin‐cephalin clotting times were increased 1.7–2.3‐ and 2.4‐fold respectively. The LD50 (i.v. mouse) was 300 μg/Kg. Its effects on uptake and stimulation of neurotransmitter synthesis and release were observed in rat brain synaptosomes. In the presence of 100 μg venom, uptake of [methyl‐3H] choline in rat brain synaptosomes was inhibited 70%, while that of 4‐amino‐n‐[U‐14C] butyric acid was inhibited 20%. The toxin also stimulated the release of [3H]‐acetylcholine from the synaptosomes. © 1992 Wiley‐Liss, Inc.
Short term effects of animal venoms on the mitotic index of the duodenal mucosa of albino rats
Authors: Sinna G. Abu , Al‐Zahaby A. , El‐Aal A. Abd , El‐Baset A. Abd , Saber T.
Published: October 2006

Short term administration of the venoms of the snakes Naja haje, Naja nigricollis, and Cerastes vipera and of the scorpion Leiurus quinquestriatus on the mitotic index of the duodenal mucosal cells of the white rat, Rattus rattus, has been studied. All the venoms increased the number of dividing cells of the duodenal mucosa significantly. Naja haje crude venom was fractionated into three fractions. Fraction I had no effect on the mitotic index whereas fractions II and III increased it significantly. Treatment of rats with Naja haje venom fractions II and III after blocking the histamine or the serotonin receptors did not affect the stimulatory action of the two venom fractions on the mitotic index, which it increased significantly. It was suggested that the venoms of Naja haje, Naja nigricollis, Cerastes vipera, and Leiurus quinquestriatus and Naja haje venom fractions possessed a mitogenic activity. Fraction II of Naja hajevenom acted through both the muscarinic and adrenergic receptors while fraction III acted on the adrenergic ones. © 1992 Wiley‐Liss, Inc.
The effects of ciguatoxin on the nerves of the teleost fish, Sillago ciliata
Authors: Flowers Andrew E. , Capra Michael F. , Cameron John
Published: October 2006

The absolute refractory period, relative refractory period, and the duration and magnitude of the supernormal period were measured after incubation of fish nerves with ciguatoxin and other channel modifying compounds, tetrodotoxin, veratridine, verapamil, and lignocaine. In vitro electrophysiological studies were carried out on the lateral line nerve of the whiting, Sillago ciliata Cuvier. Electrophysiological changes in fish nerves after exposure to ciguatoxin (0.3 MU.ml−1) and veratridine (1 × 10−5 M) are similar to changes that occur in mammalian nerves and include an increase in the absolute refractory period, the relative refractory period, and the magnitude and duration of supernormality. The effects of ciguatoxin (0.3 MU.ml−1) in fish nerves were antagonised by tetrodotoxin (5 × 10−10 M), verapamil (5 × 10−7 M), and lignocaine (1 × 10−5 g/ml−1). The nerves of Sillago ciliata used in this study responded to ciguatoxin and its antagonists in a similar manner to mammalian nerves, suggesting that these teleost nerves have no specific electrophysiological mechanism to cope with this toxin. © 1992 Wiley‐Liss, Inc.
Toxicity and trichothecene production by Fusarium acuminatum subsp. acuminatum and Fusarium acuminatum subsp. armeniacum
Authors: Wing Nicola , Lauren Denis R. , Bryden Wayne L. , Burgess Lester W.
Published: October 2006

The toxicity of cultures of Fusarium acuminatum subsp. acuminatum and Fusarium acuminatum subsp. armeniacum grown on Weet‐Bix® medium was assessed using a chick bioassay. Thirty‐nine of 45 cultures of F. a. armeniacum tested produced at least 50% mortality in the chick bioassay. In contrast, of the 26 cultures of F. a. acuminatum tested, only nine produced at least 50% mortality. Selected extracts of both subspecies were analyzed by gas chromatography after clean‐up and hydrolysis for the four main trichothecene families, namely; nivalenol (NIV), deoxynivalenol (DON), scirpentriol (Sctol), and T‐2 tetraol (T‐2tol). Levels of up to 500 μg/g and 7 μg/g of T‐2tol were detected in F. a. armeniacum and F. a. acuminatum extracts respectively. Four cultures each of F. a. armeniacum and F. a. acuminatum were also grown on two solid media (Weet‐Bix® and Vermiculite) and two liquid media (MYRO and GYEP). Culture extracts were again tested for toxicity and analyzed for trichothecene production. Cultures of F. a. armeniacum grown on the solid media and on MYRO produced the highest toxicity. Levels of up to 168, 129, 150, and 8 μg/g of T‐2tol were detected in cultures of F. a. armeniacum on Weet‐Bix®, Vermiculite, MYRO, and GYEP respectively. In contrast, only trace amounts of T‐2tol were detected in extracts of F. a. acuminatum on all media. Sctol levels of less than 0.5 μg/g were also detected in some cultures of both subspecies on solid media, but only F. a. armeniacum produced trace levels of Sctol on liquid media. Analysis without hydrolysis of F. a. armeniacum extracts revealed that the most common trichothecenes produced were T‐2 toxin and neosolaniol. These data indicate that F. a. armeniacum is a highly toxigenic fungus. © 1992 Wiley‐Liss, Inc.
Isolation of the major component in white snakeroot that is toxic after microsomal activation: Possible explanation of sporadic toxicity of white snakeroot plants and extracts
Authors: Beier Ross C. , Norman James O. , Reagor John C. , Rees Matthew S. , Mundy Bradford P.
Published: October 2006

Tremetone, the major toxic component in white snakeroot (Eupatorium rugosum Houtt) extracts, was isolated following an in vitro bioactivity assay. Microsomal activation was required to produce a product toxic to murine melanoma (B16F1) cells as well as five other mammalian cell cultures. The metabolic activation product(s) of tremetone is suspected to be responsible for the toxic activity of the plant. Tremetone is also smoothly converted to dehydrotremetone in the plant and cell free homogenates, and readily decomposes to dehydrotremetone in extracts. Dehydrotremetone is not toxic even after microsomal activation. The efficient conversion of tremetone to dehydrotremetone may explain why white snakeroot plant material and extracts have varied activities, and why a previous claim that tremetone was responsible for the toxic activity of white snakeroot was withdrawn. Rayless goldenrod extracts show the same toxic activity as white snakeroot and the toxic activity of rayless goldenrod is most likely due to tremetone. © 1992 Wiley‐Liss, Inc.
Rapid colorimetric bioassay for screening of fusarium mycotoxins
Authors: Rotter Barbara A. , Thompson Brian K. , Clarkin Sylvia , Owen Terence C.
Published: October 2006

The cytotoxicity of Fusarium mycotoxins was evaluated using a trichothecene sensitive cell line (BHK‐21, baby hamster kidney cells) in combination with the MTT‐cleavase test as an end‐point measurement. Cells tended to be more sensitive to the type A trichothecenes with midpoint cytotoxicity values ranging from 1.6 ng/ml for T‐2 toxin to 60 ng/ml for scirpentriol. The cytotoxicity value for deoxynivalenol (type B) was 112 ng/ml. The inherent disadvantage of the MTT‐assay (formation of insoluble formazan) was overcome by using the analog MTS and measuring the water‐soluble formazan directly in the culture media. The MTS‐midpoint cytotoxicity values for T‐2 toxin and deoxynivalenol (2.1 and 141 ng/ml, respectively), although slightly higher, showed a good correspondence to the MTT‐test. Both the MTT‐ and MTS‐cleavage tests are useful for evaluating the cytotoxicity of Fusarium mycotoxins. The replacement of MTT by MTS substantially reduced the number of sample processing steps and the length of time required to complete the cytotoxicity assay. © 1992 Wiley‐Liss, Inc.
Characterization of toxin III of the scorpion Leiurus quinquestriatus quinquestriatus: A new type of alpha‐toxin highly toxic both to mammals and insects
Authors: Kopeyan Charles , Mansuelle Pascal , Martin‐Eauclaire Marie‐France , Rochat Hervé , Miranda François
Published: October 2006

The primary structure of toxin III of Leiurus quinquestriatus quinquestriatus (Lqq III) was elucidated by automatic Edman degradation of the reduced and S‐carboxymethylated protein and derived tryptic peptides. Like other scorpion toxins that are active on sodium channels, Lqq III, consisting of 64 amino acids, is a 7 kDa single‐chain polypeptide crosslinked by four disulfide bridges. It belongs to the α‐toxin group, as judged by competition experiments with 125I AaH II for binding to rat brain synaptosomes (Ko.5 = 7 × 10‐−7 M). Lqq III is the first α‐toxin to be characterized that is highly toxic to mice [LD50 = μG (7.1 nmol)/kg body wt], by subcutaneous injection, insects Blatella germanica [LD50 = 60 ng (8.5 pmol)/g body wt.] and Musca domestica [LD50 = 120 ng (17 pmol)/g body wt]. When tested via the intracerebroventricular route, the toxicity for mice [55 μg (8 nmol)/kg] was of the same order as that found by subcutaneous injection, indicating that Lqq III has a higher affinity for peripheral sodium channels than for those of the central nervous system. There are three differences between the sequences of Lqq III and LqhαlT, an α‐toxin isolated from the venom of Leiurvs quinquestriatus hebraeus. These substitutions are found at positions 20,24, and 64 (Ser‐→Ala, Asp‐→Glu and His‐→Arg, respectively). Surprisingly LqhαlT is only weakly active in mice [LD50 = 5 mg (0.7 μmol)/kg], while in insects its toxicity is similar to that of Lqq III [140 ng (20 pmol)/g body wt blowfly larvae]. These observations are relevant to the definition of scorpion toxin structure‐activity relationships. © 1992 Wiley‐Liss, Inc.
Distribution and excretion of [14C] fumonisin B1 in male sprague‐dawley rats
Authors: Norred William P. , Plattner Ronald D. , Chamberlain William J.
Published: October 2006

[14C]Fumonisin B1 was biosynthetically produced by the addition of [14C]methyl methionine to a liquid culture of Fusarium moniliforme. The labeled toxin was then administered to rats intragastrically in one study and intravenously in another. The rats were killed at intervals up to 96 hr after dosing. In a third study, rats were dosed intragastrically 3 times at 24 hr intervals, and killed at intervals up to 144 hr after the first dose. After intragastric administration, up to 80 percent of the radiolabel was recovered in feces and up to 3% in urine. The remainder of the radioactivity was distributed in tissues, with the liver, kidney, and blood having the highest percentages. The radioactivity appeared to persist in these tissues for the duration of the experiment. This observation was duplicated in rats dosed intravenously, as well as the fact that urinary excretion of systemic [14C]fumonisin B1 takes place. Also observed during the intravenous study was the elimination of up to 35% of the radiolabel in feces, indicating that fumonisin B1 and/or its metabolites undergoes biliary excretion. The results obtained suggest a portion of the fumonisin B1 that is absorbed is persistent in the target organs, liver and kidney, for up to 96 hr. © 1992 Wiley‐Liss, Inc.
Pharmacological studies of the venom of an Australian bulldog ant (Myrmecia pyriformis)
Authors: Matuszek Maria A. , Hodgson Wayne C. , Sutherland Struan K. , King Roger G.
Published: October 2006

The purpose of this study was to examine some of the pharmacological actions of venom from the Australian bulldog ant Myrmecia pyriformis. M. pyriformis venom was prepared by extraction of venom sacs in distilled water and centrifugation to remove insoluble material. Venom (2 μg/ml) produced a biphasic response of isolated guinea‐pig ileum, i.e., an initial rapid contraction followed by a slower prolonged contraction. The histamine antagonist mepyramine (0.1 μM) inhibited the first phase of this response by ⋍ 80%. In the isolated rat stomach fundus strip (histamine‐insensitive), venom (2–4 μg/ml) produced only a single contraction. Responses to venom of egg‐albumin‐sensitized guinea‐pig ileum, were not significantly different before and after an anaphylactic response induced in vitro by egg albumin (0.5 mg/ml). Fluorometric assay showed that histamine accounted for 3.5 ± 0.5% of the dry weight of M. pyriformis venom. Both the lipoxygenase/cyclooxygenase inhibitor BW755C and the cyclooxygenase inhibitor indcmethacin significantly inhibited the response to venom of guinea‐pig ileum (second phase) and rat fundus strip. M. pyriformis venom caused hemolysis of guinea pig blood. The degree of hemolysis was reduced significantly when boiled venom was used. No evidence was found that the venom contains acetylcholine, bradykinin, or 5‐hydroxytryptamine or that the venom releases histamine from guinea‐pig ileum. However, the results indicate that the venom contains histamine‐like activity. In addition the venom was found to cause the release of cyclooxygenase products and to contain a heat‐sensitive hemolytic factor. © 1994 Wiley‐Liss, Inc.
10‐, 12‐, and 29‐Hydroxybullatacinones: New cytotoxic annonaceous acetogenins from nnona bullata rich (annonaceae)
Authors: Gu Zhe‐Ming , Fang Xin‐Ping , Hui Yu‐Hua , McLaughlin Jerry L.
Published: October 2006

In our continuing activity‐directed search for new antitumor compounds, using brine shrimp lethality (BST), mixtures of three additional pairs (1‐6) of bis‐THF ketolactone acetogenins were isolated from the ethanol extract of the bark of Annona bullata Rich. (Annonaceae). Compared with (2,4‐cis and trans)‐bullatacinone (7 and 8), these new compounds each have one more aliphatic OH group at a different position on the hydrocarbon chain, and, thus, were named (2,4‐cis and trans)‐10‐hydroxybullatacinone (1 and 2), (2,4‐cis and trans)‐12‐hydroxybullatacinone (3 and 4), and (2,4‐cis and trans)‐29‐hydroxybullataci‐none (5 and 6). These mixtures all showed potent activities in the brine shrimp lethality test (BST) and exhibited cytotoxicities comparable to those of adriamycin against human solid tumor cells in culture with selectivities exhibited especially toward the breast cancer cell line (MCF‐7). © 1994 wiley‐Liss, Inc.
Pharmacokinetic fate and pathological effects of14C‐fumonisin B1 in laying hens
Authors: Vudathala Daljit K. , Prelusky Dan B. , Ayroud Mejid , Trenholm H. Locksley , Miller J. David
Published: October 2006

Presence of fumonisin B1(FB1), a major metabolite ofFusarium moniliforme, in corn is of great concern to both human and animal health because of its wide range of toxicity. The pharmacokinetics of FB1was studied in laying hens following oral and intravenous administration of14C‐labelled FB1. After iv dosing (2.0 mg = 23.68 kBq/kg bw) plasma radioactivity underwent a very rapid bi‐exponential decline (t1/2 α = 2.5 ± 0.3 min; t1/2 β = 48.8 ± 11.2 min) with negligible levels measured after 4–6 hr. Mean value for the apparent volume of distribution at steady state (Vdss) was 18.27 ml/kg, apparent volume of central compartment (Vdβ) was 82.20 ml/kg and plasma clearance was 1.18 ml/min/kg. At 24 hr post‐dosing only trace residues were present in liver, kidney, and cecum. When dosed by the oral route (2.0 mg = 47.36 kBq/kg bw), systemic absorption of fumonisin appeared to be poor (F = 0.71 ± 0.5%) with peak plasma concentrations of only 40–145 dpm/ml (equivalent to 28–103 ng FB1and/or metabolites per ml) between 1.5 and 2.5 hr. At 24 hr post‐dosing only trace amounts were present in crop, liver, kidney, small intestine, and cecum. In both orally and iv dosed birds almost all (97.7 ± 3.73%) of the radioactivity was recovered in excreta by the end of the 24 hr experiment period and no residues were found in eggs laid during the 24 hr post‐dosing period. Pathological evaluation of laying hens fed 110 g daily of feed containing 4 mg FB1/kg for a 28 day duration revealed no significant gross or histological lesions between test and control birds sacrificed at various times (7, 14, 21, 28 d) during the feeding period. Published 1994 Wiley‐Liss, Inc.
Sesquiterpenoid unsaturated dialdehydes increase the concentration of intracellular free Ca2+ in human neuroblastoma SH‐SY5Y cells
Authors: Forsby Anna , Witt Robin , Walum Erik
Published: October 2006

The effect of the three sesquiterpenoid unsaturated dialdehydes–polygodial, isovelleral, and epipolygodial—on intracellular free Ca2+ concentration, [Ca2+]i, was investigated in the human neuro‐blastoma cell line SH‐Sy5y. [Ca2+]i was measured by the Fura‐2 spectrophotofluorometric technique in multi‐cell and single‐cell experiments. Polygodial and isovelleral induced an increase in [Ca2+]i at low concentrations (0.1 and 0.5 μg/ml, respectively) but epipolygodial affected [Ca2+]i only at a high concentration (10 μg/ml). The results indicated that there was a relationship between the effect on [Ca2+]i and the pungency of the sesquiterpenes tested. Experiments in a Ca2+ ‐free extracellular solution showed that Ca2+ was also released from intracellular calcium stores. Images from single‐cell experiments indicated that polygodial induced fluctuations in the [Ca2+]i in some cells. The mechanism behind the sesquiterpene induced increase of the [Ca2+]i was not identified but a possible mobilization of inositol phosphates is considered. © 1994 wiley‐Liss, Inc.
In vitro transformation of the Fusarium mycotoxins deoxynivalenol and zearalenone by the normal gut microflora of pigs
Authors: Kollarczik Birgit , Gareis Manfred , Hanelt Monika
Published: October 2006

The biotransformation of the Fusarium mycotoxins deoxynivalenol and zearalenone by the normal bacterial gut flora of pigs was examined in this in vitro study For that purpose, suspensions of intestinal contents (duodenum, jejunum, caecum, colon, rectum) of porcine origin were incubated anaerobically with deoxynivalenol (DON) or zearalenone (ZEA). DON and ZEA were degraded by the flora of the caudal segments (caecum, colon, rectum) of the gut—particularly the colon content—whereas the microorganisms of the cranial segments (duodenum, jejunum) exhibited no transforming activity. DON was showed to be deepoxidated, ZEA was hydrolyzed to a‐zearalenol and an unknown metabolite. The transformation of DON was correlated with a loss of cytotoxicity, which could be demonstrated in the MTT(3‐[4,5‐dimethylthiazol‐2yl]‐2,5‐diphenyltetrazolium bromide)‐cell‐culture assay using swine kidney cells as target cells.

The results of the study presented here correspond with the data found in in vivo studies. On the basis of these findings one could conclude that this in vitro method seems to be well suited to the study of the transformation of mycotoxins by the microflora of the gut. The in vitro study is cheaper than a feeding trial, and the preliminary information on the metabolism of mycotoxins obtained in such studies is helpful in designing feeding trials more clearly. Besides the simple and fast handling, reproducibility and the protection of the animals studied are further advantages of this in vitro method. In connection with the MTT‐cell‐culture assay, additional information about the cytotoxic potential of the bacterial transformation products can be obtained. © 1994 Wiley‐Liss, Inc.
Effects of sterigmatocystin and T‐2 toxin on the induction of unscheduled DNA synthesis in primary cultures of human gastric epithelial cells
Authors: Ji Xinhua , Ke Yang , Ning Tao , Liang Yixin , Wang Diansheng , Shi Guizhi
Published: October 2006

Primary cultures of human gastric epithelial cells were tested for induction of unscheduled DNA synthesis (UDS) by Sterigmatocystin (ST) and T‐2 toxin. Autoradiographic results indicated that ST (10−6‐10−4M) induced UDS in the presence of S9 activation system. The repair rates were 24‐91% (netgrains ≥ 3) and 2‐71% (net grains ≥ 5). T‐2 toxin did not induce UDS in this study. © 1994 wiley‐Liss, Inc.
Influence of glucocorticoids and activated charcoal on the lethality of rats after acute poisoning with T‐2 toxin, diacetoxyscirpenol, or roridin A
Authors: Hunder Göran , Fichtl Burckhard , Forth Wolfgang
Published: October 2006

Lethal doses of the trichothecene mycotoxins T‐2 toxin (1.5 mg/kg), diacetoxyscirpenol (DAS; 2.3 mg/kg) or roridin A (1.3 mg/kg) were intravenously administered to rats. When rats were treated with either activated charcoal (Superchar liquid, Norit A; 1 g/kg, pol or dexamethasone (8 mg/kg, iv) 30 min after poisoning with one of the trichothecenes, lethality was only marginally reduced. However, when the combination of activated charcoal (Superchar liquid or Norit A) and dexamethasone was administered, the survival rate of animals after 30 days was significantly enhanced by up to 50%. Comparison between 2 preparations of activated charcoal, Norit AR with a surface area of 1,000 m2/g and Superchar liquidR with a surface area of 3,000 m2/g, each in combination with dexamethasone, revealed no difference in their therapeutic efficacy. Prednisolone (60 mg/kg) was as effective as dexamethasone (8 mg/kg), each administered with activated charcoal, in preventing death in acute T‐2 toxicosis.
Isolation and structure determination of terminalin a toxic condensed tannin from Terminalia oblongata
Authors: Oelrichs Peter B. , Pearce Clive M. , Zhu Jin , Filippich Louie J.
Published: October 2006

Terminalia oblongata (yellow wood) is a small deciduous tree growing over an area of central Queensland that supports a large proportion of this state's cattle population. Cattle and sheep that consume yellow wood leaves are poisoned and die. Severe losses of these animals can occur, and this problem is considered the main cause of economic loss to the cattle industry in the area apart from drought. A new toxic condensed tannin, terminalin was isolated from Terminalia oblongata. Its structure was deduced following NMR, IR, UV, MS analyses and in the knowledge that these data show good correlations to those obtained from the related punicalagin molecule which is present in the plant. Terminalin has a high toxicity (20 mg/kg) to white Quackenbush male mice and produces a vascular renal necrosis with slight liver necrosis, unlike punicalagin, which produces liver lesions but not kidney lesions. Similar results were obtained with sheep. A most interesting aspect is that there are two different specific toxins in the plant. © 1994 wiley‐Liss, Inc.
Scytophycin Production by Axenic Cultures of the Cyanobacterium Scytonema ocellatum
Authors: Patterson Gresory M. L. , Bolis Christine M.
Published: October 2006

Nonaxenic clones prepared from the cyanobacterium Scytonema ocellatum Lyngbye ex Bornet et Flahault strain FF‐66‐3 exhibited a high degree of heterogeneity with respect to tolytoxin titer. Thirty‐four of 114 clones (29.8%) isolated by fragmentation of Scytonema filaments did not produce detectable amounts of tolytoxin in culture. One clone (designated SO127) produced approximately twice as much tolytoxin as the parental culture and continued to produce tolytoxin after repeated subculture. Three axenic clones were prepared from SO127 by a combination of antibiotic treatment and mechanical separation. Although axenic cultures yielded slightly greater biomass, tolytoxin content did not significantly differ between axenic and nonaxenic cultures, indicating that bacteria do not play a role in tolytoxin biosynthesis. Bacterial cultures derived from S. ocellatum did not produce detectable amounts of tolytoxin. © 1994 Wiley‐Liss, Inc.
Studies on the detection of okadaic acid in mussels: Preliminary comparison of bioassays
Authors: Baut Claire Marcaillou‐Le , Amzil Zouher , Vemoux Jean‐Paul , Pouchus Yves‐François , Bohec Madeleine , Simon Jean‐François
Published: October 2006

Diarrheic toxins, especially okadaic acid, are detected nearly every year in mussels on French coasts. The monitorins network determines the toxicity of these shellfish by using a mouse test now considered unsatisfactory from an ethical point of view. Two alternative methods have been investigated: the daphnia test, for which there is a standardized method used routinely in ecotoxicolosy, and a cytotoxicity test on the KB cell line developed for this study. Using the same samples, the results of these two tests were compared with those obtained by chemical analysis (HPLC okadaic acid assay) or the mouse test. Linear regression studies showed that results for the two bioassays were well correlated with those for HPLC or the mouse test. © 1994 Wiley‐Las, Inc.
Toxicology and seafood toxins: Domoic acid
Authors: Iverson Frank , Truelove John
Published: October 2006

Marine and terrestrial food sources are susceptible to contamination by various industrial chemicals and microbial pathogens. Both types of hazard are amenable to regulatory assessment using a single toxicology data base, along with some knowledge of contaminant levels and consumption figures for food. On the other hand, regulatory problems persist with acutely toxic naturally occurring phycotoxins, which may accumulate unpredictably to toxic levels in seafood. However, a scarce supply of pure toxin often precludes the availability of acceptable toxicology studies describing their biological effects. An exception to this situation is domoic acid, a neurotoxic phycotoxin that produced numerous cases of severe human intoxication which demanded extensive toxicological study. This paper describes a series of ongoing studies initiated in the wake of the outbreak of domoic acid toxicity that occurred in 1987 in Eastern Canada. © 1994 wiley‐Liss, Inc.
stachybotrys toxins. 1
Authors: Jarvis Bruce B. , Salemme Jean , Morals Anselmo
Published: October 2006

Cultures of several isolates of Stachybotrys chartarum have produced a series of cytotoxic macrocyclic trichothecenes including two newly characterized conseners: isosatratoxin G and S‐isosatratoxin H. Nine immunosuppressant phenylspirodrimanes (1–9) were isolated and characterized, the majority of which are newly reported compounds. © 1995 Wiley‐Liss, Inc.
Role of mycotoxins in human and animal nutrition and health
Authors: Smith John E. , Solomons Gerald , Lewis Chris , Anderson John G.
Published: October 2006

The impact of mycotoxins on human and animal health is now increasingly recognised. Mycotoxin entry to the human and animal dietary systems is mainly by ingestion but increasing evidence also points at entry by inhalation. Mycotoxins exhibit a wide array of biological effects and individual mycotoxins can be mutagenic, carcinogenic, embryotoxic, teratogenic, or oestrogenic. Average levels of ingestion of currently known mycotoxins in most EEC countries are rather low. Little is known about the consequences to humans of such mycotoxin intakes. Establishing a causal relationship between mycotoxin exposure and human disease is complicated by uncertainties associated with human epidemiological studies. Analysis of mycotoxin adducts in human populations can act as a surrogate for human genotoxicity. Mycotoxins can also be immunosuppressive and appear to involve cellular immune phenomena and non‐specific humoral factors associated wtih immunity. © 1995 Wiley‐Liss, Inc.
Natural toxins and protective factors in brassica species, including rapeseed
Authors: Heaney Robert K. , Fenwick G. Roger
Published: October 2006

Many plant secondary metabolites exhibit a wide range of dose‐related physiological properties when included in the diet of animals and man. Within the brassica family, the glucosinolates, a group of sulphur‐containing glucosides have been the subject of a vast amount of study and the effects of dietary inclusion of such compounds or their metabolites on the health of animals and man are briefly reviewed. Although excessive amounts of glucosinolates in animal feed formulations may reduce growth and performance as well as affecting thyroid, liver, and kidney function, there is little evidence of such effects in man. On the contrary, compounds derived from glucosinolates as a consequence of enzymic breakdown or metabolism have been shown to activate mechanisms which moderate or reverse carcinogenic processes. Such effects may contribute to the net anti‐carcinogenic benefit attributed to these vegetables in numerous epidemiological studies. © 1995 Wiley‐Liss, Inc.
Analysis of mycotoxins in food and feed: Certification of DON in wheat and maize
Authors: Gilbert John
Published: October 2006

Worldwide there are either statutory limits or in some instances advisory guidelines for the maximum levels of mycotoxins in foods and feeds. These limits which have been agreed for the protection of human health and as standards for trade are often set at surprisingly low levels in view of both the problems of sampling and the abundant evidence of the difficulties of mycotoxin analysis, particularly so when approaching the limits of detection. Improved methodology for mycotoxins and improvements in performance even of expert laboratories have, however, been achieved through intercomparison exercises organised by the EC Measurement and Testing programme (formerly BCR). On a wider scale, participation in proficiency testing through schemes such as the UK Food Analysis Performance Assessment Scheme (FAPAS) have indicated that between 10 and 40% of laboratories experience difficulties in obtaining satisfactory results in monitoring mycotoxins. Reference materials provide an important means of checking method performance. BCR has made a unique contribution in the production and certification of maize and wheat reference materials naturally contaminated with the Fusarium mycotoxin 4‐deoxynivalenol (DON), which has now been available for purchase for some 2 years. © 1995 Wiley‐Liss, Inc.
Ochratoxin A in cereals and the BCRxs‐M&T‐projects
Authors: Wood Gillian M. , Entwisle A. Catherine , Patel Susan , Hald Bénédicte , Boenke Achim
Published: October 2006

Reliable analytical procedures and certified reference materials are essential for the establishment and enforcement of tolerance levels for ochratoxin A in foods. The inadequacy of analytical procedures, together with the need for certified reference materials, led the Commission of the European Communities Community Bureau of Reference (BCR) to undertake a project to prepare suitable reference materials for ochratoxin A in wheat, in order to imporve methodology and to harmonise agreement of results between member states. The first intercomparison study indicated problems in the analysis due to the influence of co‐extractives in the matrix, and demonstrated that further work was necessary to improve recovery, clean‐up and reproducibility.

The second intercomparison study, in the EC Measurements and Testing Programme, correlated the performance of the different methods for ochratoxin A measurement in a separate batch of contaminated wheat, and compared novel immunoaffinity column methods with the standard laboratory methods. Results were obtained from 26 laboratories within 11 European countries, which therefore gives a good representation of the scope of methods currently used in Europe. Considerable improvements in the determination of ochratoxin A were noted compared with the first intercomparison study. © 1995 Wiley‐Liss, Inc.
IARC activities in mycotoxin research
Authors: Castegnaro Marcel , Wild Christopher P.
Published: October 2006

The creation of the International Agency for Research on Cancer (IARC) in May 1965 occurred only two years after publication of the chemical structure of the aflatoxins, and the investigation of a possible link between exposure to these compounds and liver cancer incidence was initiated by IARC as early as 1968. Thus, mycotoxins were one of the first topics of research at IARC and the Agency's special interest in cancer in developing countries has contributed to a sustained effort in this research field. The work performed comprises a number of aspects including laboratory research into mechanisms of action and methods for destruction of mycotoxins, epidemiological studies, and through evaluation of the carcinogenic potency of these toxins in the “IARC Monographs on the Evaluation of the Carcinogenic Risks to Humans.” A particular feature has been the integration into epidemiological studies of biomarkers of mycotoxin exposure (e.g., to aflatoxin, ochratoxin A) developed in the IARC laboratories. The above research areas are described briefly below and future activities are discussed in relation to present knowledge and the possibilities of achieving primary prevention of cancer. Another field of activity in which IARC has been strongly involved is that of quality assurance with the organisation of the mycotoxin check sample programme [Friesen, 1989: J ToxicolToxin Reviews 8:363‐373]. This activity will, however, not be discussed in this article in view of space limitations. © 1995 Wiley‐Liss, Inc.
Isolation and identification of a compound from avocado (Persea americana) leaves which causes necrosis of the acinar epithelium of the lactating mammary gland and the myocardium
Authors: Oelrichs Peter B. , Ng Jack C. , Seawright Alan A. , Ward Annemarie , Schäffeler Lothar , Macleod John K.
Published: October 2006

It is well known that when lactating livestock eat avocado (Persea americana) leaves they may develop non‐infectious mastitis and agalactia. This is associated with extensive coagulative necrosis of the secretory acinar epithelium and interstitial oedema, congestion, and haemorrhage. Similar lesions have been produced in mammary glands of lactating mice fed a diet containing a small percentage of freeze‐dried avocado leaf. Tests using these animals have been used to isolate the active principle, termed persin, from avocado leaves. The purified persin was examined using IR, NMR, and UV spectroscopy and mass spectrometry, and identified as (Z,Z)‐1‐(acetyloxy)‐2‐hydroxy‐12,15‐heneicosadien‐4‐one. Persin has previously been isolated from avocado leaves and shown to have antifungal properties and to be toxic to silkworms. Our tests have shown that persin at the dose rate of 60‐100 mg/kg has the same effect on mammary glands in lactating mice as leaves from avocado. Enantioselective syntheses of the R and the S isomers of persin and related derivatives were carried out. These compounds were tested for activity required to induce widespread lactating mammary gland necrosis in mice, and only the R isomer was found active. At doses of persin above 100 mg/kg necrosis of myocardial fibres may occur and hydrothorax may be present in severely affected animals. The mechanism of action of persin on both the mammary gland and the myocardium remain to be resolved. © 1995 Wiley‐Liss, inc.
Isolation of a compound from Eupatorium adenophorum (Spreng.) [Ageratina adenophora (Spreng.)] causing hepatotoxicity in mice
Authors: Oelrichs Peter B. , Calanasan Cleofe A. , Macleod John K. , Seawright Alan A. , Ng Jack C.
Published: October 2006

Regular insestion of Eupatorium adenophorum [Ageratina adenophora (Spreng.)] or Crofton weed causes chronic pulmonary disease in horses mainly in Australia, New Zealand, and the Himalayas. The disease is characterised by pulmonary interstitial fibrosis, emphysema, alveolar epithelisation and reduced tolerance to exercise. Horses apparently are the only animals affected and there are numerous reports of farms losing all their horses. The disorder was produced experimentally in horse feeding trials, and it was shown that characteristic lesions occurred in the lungs. In studies with laboratory animals, mice were shown to be suitable test animals, but in this species lesions occur in the liver rather than the lungs. The hepatic injury in these animals is characterised by multiple areas of focal necrosis of the parenchyma associated with degeneration and loss of the epithelium lining the small bile ducts. The active principle 9‐oxo‐10,11 dehydroagerophorone responsible for these lesions in mice has been isolated from E. adenophorum. Although the compound has been shown to exhibit toxicity to larvae of invertebrate species, no mammalian toxicity studies have been previously reported involving the isolated toxin. The mechanism of the toxic effect of the compound as well as its possible relevance to the respiratory disease in the horse remain to investigated. © 1995 Wiley‐Liss, Inc.
Cooliatoxin, the first toxin from Coolia monotis (dinophyceae)
Authors: Holmes Michael J. , Lewis Richard J. , Jones Alun , Hoy Ashley W. Wong
Published: October 2006

Coolia monotis is a benthic dinoflagellate previously thought to be non‐toxic. We describe a new toxin, named cooliatoxin, purified from cultures of a strain of C. monotis isolated from Australia. Cooliatoxin is likely a mono‐sulphated, polyether toxin (Mr = 1,062; i.p. LD50 = 1 mg/kg in mice) that induces hypothermia and respiratory failure in mice after a pronounced delay period during which there are no obvious signs of intoxication. These signs in mice are similar to those reported for the shellfish toxin named yessotoxin and the molecular weight of cooliatoxin corresponds to the mono‐sulphated form of yessotoxin, suggesting that cooliatoxin may be an analogue of yessotoxin. Cooliatoxin has no effect on the mouse phrenic nerve or diaphragm musculature in vitro but causes initial stimulation and subsequent block of unmylenated nerves in vitro. In isolated guinea pig left atria, cooliatoxin (above 20 nm) induced a slow developing, concentration dependent, sustained positive inotropic response. Propranolol or tetrodotoxin reversed the positive inotropic effects, indicating that the majority of the cooliatoxin induced response was mediated by stimulation of nerves associated with the atrial musculature, resulting in the release of noradrenaline. Cooliatoxin induced transient contractions in isolated guinea pig vas deferens preparations. Atria and vas deferens preparations were tachyphylactic to a second equivalent dose of cooliatoxin applied after the effects of the first dose had diminished. The observed in vitro effects of cooliatoxin on peripheral nerves are unlikely to account for the lethal effects in mice and a central action of this toxin is suspected. © 1995 Wiley‐Liss, Inc.
Documented case of ciguatera on the Mexican Pacific Coast
Authors: Lechuga‐Devéze Carlos H. , Sierra‐Beltrán Arturo P.
Published: October 2006

Serranidae and Labridae fish caught in 1993 at Alijos Rocks, 300 miles off East Magdalena Bay, Southern Baja California, caused severe illness of a fishing boat crew. The described symptoms resembled those of ciguatera. The presence of ciguatera‐like toxins was confirmed on extracts from these fish using the mouse bioassay procedure, showing activities between 220 to 390 mouse units (M.U.). The founding of ciguatoxin at Alijos Rocks (24° 57′ N, 115° 45′ W) extends to the northeast its geographical distribution in the Pacific and locates the outbreak near the continental coastline. © 1995 Wiley‐Liss, Inc.
Enhancement of domoic acid production by reintroducing bacteria to axenic cultures of the diatom Pseudo‐nitzschia multiseries
Authors: Bates Stephen S. , Douglas Donald J. , Doucette Gregory J. , Léger Claude
Published: October 2006

Axenic cultures of Pseudo‐nitzschia multiseries (formerly Pseudonitzschia pungens f. multiseries) produce less domoic acid (DA) than the original bacteria‐containing cultures. Bacterial strains isolated from two nonaxenic P. multiseries clones were reintroduced individually into cultures of three axenic P. multiseries strains. The bacteria did not substantially affect division rates or cell yields. However, they did cause a 2‐ to 95‐fold enhancement of DA production (per cell basis) relative to the axenic culture, depending on the P. multiseries and bacterial strain used. Bacteria isolated from a nontoxic Chaetoceros sp. culture also enhanced DA per cell (by 115‐fold), showing that it is not necessary for the bacteria to be isolated from a toxic culture in order to enhance toxin production. There was no evidence of intracellular bacteria in disrupted P. multiseries cells obtained from axenic cultures. Our results demonstrate an important, but nonessential, role of extracellular bacteria in DA production. Characterization of the bacterial strains using morphology, substrate utilization, and restriction fragment length polymorphism (RFLP) analyses clearly showed that we had isolated different species of bacteria from the various nonaxenic cultures. We conclude that not one but several bacterial species enhance DA production by P. multiseries. © 1995 wiley‐Liss, Inc.
Ochratoxin a levels in human milk and related food samples: An exposure assessment
Authors: Miraglia Marina , De Dominicis Alessandra , Brera Carlo , Corneli Silvia , Cava Egle , Menghetti Ettore , Miraslia Elena
Published: October 2006

Ochratoxin A (OA) is a mycotoxin detected in a variety of food and feeds mostly from countries with temperate or continental climate, because the fungi that produce it, mainly Aspergillus ochraceus, Pénicillium verrucosum, and Pénicillium viridicatum, can grow under a great variety of climate conditions. The aim of this article was, firstly, to confirm the occurrence of OA in human milk in Italy. Then, a preliminary calculation of OA intake via human milk was made, from ingested food. For this investigation, food and milk samples were collected, continuously for a week, from 4 lactating mothers. The obtained results revealed a significant exposure of sucklings and mothers to OA levels higher than the tolerable daily intake as estimated from animal models. On the basis of these data, a major effort in planning surveillance and research programs to control OA contamination in food, feed, and biological fluids should be pursued. © 1995 Wiley‐Liss, Inc.
Pediatric T‐cell post‐transplant lymphoproliferative disorder after solid organ transplantation
Authors: Yang Fan , Li Ying , Braylan Raul , Hunger Stephen P. , Yang Li‐Jun
Published: October 2006

Post‐transplant lymphoproliferative disorder (PTLD) is the most common treatment related malignancy that occurs after solid organ transplantation (SOT). PTLD has extended from its initial description as an Epstein–Barr virus (EBV)‐driven B‐cell proliferation to include EBV‐negative and non B‐lineage cases. T‐cell PTLD (T‐PTLD) is rare in both adults and children. We report two cases of pediatric T‐PTLD after SOT (liver and lungs) and review cases reported in the literature. Both patients had a bimodal response to therapy with initial eradication of bulky nodal disease with regimens typically used to treat leukemia, but persistence of low‐level clonal T‐cells in marrow, CSF and lung in one case. Pediatr Blood Cancer 2008;50:415–418. © 2006 Wiley‐Liss, Inc.
A pregnancy register of patients receiving carbamazepine in the UK
Authors: Pearse Sonja B. , Rodriguez Luis Alberto Garcia , Hartwell Caroline , Russell Gordon
Published: October 2006

From 1978 to 1990, CIBA‐GEIGY Pharmaceuticals (UK) were notified of the pregnancy outcome of 154 women who were being treated with Tegretol® (carbamazepine) during their pregnancy. The first contact of these reports occurred either before the end of the pregnancy (prospective reports) or after the result of the pregnancy was known (retrospective reports). Prospective reports were followed up in order to ascertain details of each pregnancy and the health status at birth of the offspring. The same information for the retrospective reports was collected after the pregnancy outcome occurred. Three possible outcomes of pregnancy were identified: (1) Patients whose pregnancies resulted in normal healthy babies, (2) patients whose pregnancies ended in premature spontaneous abortion and (3) patients whose pregnancies resulted in babies with congenital malformations. A total of 88 patient's reports were prospective. Of these, 75 pregnancies resulted in normal babies, 9 in spontaneous abortions and 4 in abnormal babies (5%). A total of 65 patient's reports were retrospective. Of these, 23 pregnancies resulted in normal babies, 8 in spontaneous abortions and 34 in abnormal babies (60%). This major reporting bias in the retrospective group discourages its use in the quantitative safety assessment of medicines given to pregnant women.