bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological activities of Synanceja horrida (stonefish) venom
Authors: Khoo H. E. , Yuen R. , Poh C. H. , Tan C. H. 
Published: October 2006

AbstractSome 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

AbstractShort 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

AbstractThe 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

AbstractThe 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

AbstractTremetone, 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

AbstractThe 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

AbstractThe 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

Abstract[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

AbstractThe 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

AbstractIn 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

AbstractPresence 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

AbstractThe 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

AbstractThe 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

AbstractPrimary 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

AbstractLethal 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

AbstractTerminalia 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

AbstractNonaxenic 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.