1,721,029 research outputs found
Epidemiology of animal intoxication by plant toxins in Europe
No full textIn Europe, plants are responsible for many animal poisoning cases. Frequent culprits include Nerium oleander (oleander) containing cardiac glycosides, Taxus baccata (european yew) containing taxine alkaloids, Rhododendron spp. containing grayanotoxins, Allium spp. containing organosulphur compounds and plants containing cyanogenic glycosides.
Livestock and horses are particularly at risk of being poisoned by Datura stramonium (Jimson weed) containing tropane alkaloids, Hypericum perforatum (St. John’s wort) containing hypericin, which is a photodynamic toxin, Quercus spp. (oak) containing tannins and tannin metabolites, Robinia pseudoacacia (black locust) containing the toxalbumin robin and Senecio spp. (ragworts and groundsels) containing pyrrolizidine alkaloids. Another plant that is found throughout Europe and may pose a hazard to ruminants and horses is Pteridium aquilinum (bracken fern) containing two poisonous agents: ptaquiloside and the enzyme thiaminase. Pets are usually poisoned by house or garden plants. The list of plants commonly responsible for pet poisoning includes Convallaria majalis (lily of the valley) containing cardiac glycosides, Euphorbia pulcherrima (poinsettia) containing diterpene esters and Ricinus communis (castor bean) containing the toxalbumin ricin. Several house plants that are very common such as Anthurium spp. (anthurium), Dieffenbachia spp. (dumb cane), Philodendron spp. (philodendron) Spathiphyllum spp. (peace lily), and Zantedeschia spp. (calla lily) should also be included in the list as they contain insoluble oxalates. Cycas revoluta (sago palm) may also represent a threat for pet health, particularly in the case of dogs. The compounds believed to be responsible for toxicity are glycoside cycasin, an aminoacid (b-methylamino-L-alanine), and an unidentified high molecular weight compound. Ingestion of lilies of genera Lilium and Hemerocallis, whose toxic principle is still unknown, can cause renal failure in cats
Effects of fusariotoxins in the equine species
No full textFumonisins, trichothecenes and zearalenone are the most commonly occurring Fusarium mycotoxins in
cereal grains and animal feed. In this review, the toxicity of these mycotoxins in horses is considered with
particular reference to recent data on specific and proposed syndromes. Compared to other animal species,
very little information is available on the adverse effects of fusariotoxins in horses. Fumonisin B1
(FB1) is the causative agent of leukoencephalomalacia, which is typified by depression, aimless circling,
head pressing, paresis, ataxia, blindness and death. FB1 has also been shown to cause liver damage and
cardiovascular dysfunction. Exposure to deoxynivalenol in conjunction with other fusariotoxins seems
to be associated with reduction of feed intake and decrease in bodyweight, whilst the T-2 Fusarium mycotoxin
may typically induce oral lesions and zearalenone has been implicated in reproductive disorders.
Many questions remain on the synergic effects of fusariotoxins and on a possible relationship between
mycotoxins and equine colic
Plants poisonous to horses in Europe
No full textPoisoning of horses by plants is a relatively common veterinary problem and may occur when the fresh plant is ingested in pasture or when the plant contaminates hay, silage and feed. In Europe, horses are particularly at risk of poisoning by Cynoglossum officinale (houndstongue), Datura stramonium (jimson weed), Hypericum perforatum (St. John's wort), Nerium oleander (oleander), Pteridium aquilinum (bracken fern), Robinia pseudoacacia (black locust), Senecio jacobaea (tansy ragwort), Taxus baccata (European yew) and Thuja occidentalis (white cedar). For each of these poisonous plants the information given in this review includes plant distribution, conditions of poisoning, toxic active principles and clinical signs
IN VITRO EFFECTS OF FUMONISIN B1 ALONE AND COMBINED WITH DEOXYNIVALENOL OR ZEARALENONE ON PORCINE GRANULOSA CELL PROLIFERATION AND STEROIDOGENESIS
Full text linkFumonisins, zearalenone and trichothecenes, such as deoxynivalenol (DON) and T-2 toxin, are the major Fusarium mycotoxins occurring throughout the world in cereal grains and animal feeds. Direct ovarian effects of fumonisin B1 (FB1) and its interaction with DON or α-zearalenol (α-ZOL), zearalenone major active metabolite, have so far not been investigated. Thus, the goal of this thesis was to determine if FB1, alone or combined with DON or α-ZOL, can impair swine reproductive activity via affecting granulosa cell function. To this aim, two different studies were designed.
In the first study the effects of FB1 alone and combined with DON or α-ZOL on granulosa cell proliferation were evaluated. Porcine granulosa cells from small ovarian follicles (1-5 mm) were cultured for 2 days in 5% fetal bovine serum and 5% porcine serum-containing medium followed by 2 days in serum-free medium containing FB1 at various doses (0, 0.01, 0.4, 10 and 14 μM) and combinations. At the end of the experiments, numbers of granulosa cells were determined using a Coulter counter. The results revealed that FB1 had inhibitory effects on granulosa cell proliferation at doses ≥ 10 μM. DON (3.4 μM) strongly inhibited (by 80%; P < 0.0001) granulosa cell proliferation and no significant difference was detected in combination with FB1 (10 μM). α-ZOL (9.4 μM) showed a stimulatory effect (P < 0.01) on granulosa cell numbers, even when treated in combination with FB1 (10 μM).
In the second study the effects of FB1 alone and combined with DON or α-ZOL on granulosa cell steroid production and gene expression were investigated. Porcine granulosa cells from small follicles (1-5 mm) were cultured as described above. At the end of the experiments, concentrations of progesterone and estradiol in culture medium were determined by radioimmunoassays. Real-time RT-PCR was used to elucidate the effects of FB1 on gene expression of P450scc (CYP11A1) and aromatase (CYP19A1). All doses of FB1 (i.e., 0.01, 0.4, 10 and 14 μM) had no significant effect on estradiol production, whereas FB1 showed a stimulatory effect on progesterone production induced by FSH plus insulin-like growth factor-I (IGF-I) at 10 and 14 μM. α-ZOL (9.4 μM) increased (P < 0.0001) FSH plus IGF-I-induced progesterone production by 51%. Combination of FB1 with α-ZOL resulted in an increase of progesterone production (91%; P < 0.0001) that was significantly higher than that induced by either Fusarium mycotoxin alone. DON drastically inhibited (by 74%; P < 0.0001) progesterone production and FB1 had little effect on this response. α-ZOL had no effect on FSH plus IGF-I-induced estradiol production, whereas decreased (P < 0.05) estradiol production when co-treated with FB1. DON (3.4 μM) strongly inhibited (by 67%; P < 0.0001) estradiol production and no difference was detected in combination with FB1 (10 μM). FB1 (10 μM) had no effect on granulosa cell CYP19A1 mRNA abundance, whereas decreased (by 23%; P < 0.0001) granulosa cell CYP11A1 mRNA abundance induced by FSH plus IGF-I.
In conclusion, the present thesis indicates that FB1 has direct effects on porcine granulosa cell proliferation, steroid production and gene expression and provides information on the interactions between FB1 and DON or α-ZOL in granulosa cells. These interactions and direct ovarian effects should be considered in swine reproductive failures
Aflatossicosi nell'equino
No full textAflatoxins are a group of mycotoxins produced by Aspergillus, spp. A. flavus and parasiticus. Peanuts, maize, coconut cake and cotton cake are the most contaminated feeds. Aflatoxin B1 (AFB1) is the most common and the most thoroughly studied for its high toxicity in humans as in different animal species. The target organ of AFB1 is the liver. Instead of other animal species, published information related to the toxicity of this mycotoxin in Equine are scarce. The major clinical symptoms of aflatoxicosis observed in this species include ataxia, tremor, loss of appetite, anorexia, weight loss, icterus, haemorrhages
Toxicological effects of aflatoxins in horses
No full textAflatoxins are a group of mycotoxins principally produced by Aspergillus flavus and A. parasiticus, which are both natural contaminants of food and feedstuff. Aflatoxin B1 is the most prevalent member of this group that is normally detected and is the most powerful hepatocarcinogen known. Few naturally occurring episodes of aflatoxicosis in horses have been reported in the literature. Indeed, the published information about aflatoxin exposure, metabolism and the effects on horses is limited and controversial, possibly indicating a lack of awareness rather than the rarity of the occurrence. The target organ in horses, as in other animal species, is the liver and horses suffering from aflatoxicosis show signs of inappetence, depression, fever, tremor, ataxia and cough. Necropsy findings include a yellow-brown liver with centrilobular necrosis, icterus, haemorrhage, tracheal exudates and brown urine. A possible link between aflatoxin exposure and chronic obstructive pulmonary disease has been hypothesised
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
