Topic:Carcinogenesis
Carcinogenesis in horses refers to the process by which normal cells transform into cancer cells. This transformation involves a series of genetic and epigenetic changes that disrupt normal cellular regulation, leading to uncontrolled cell growth and tumor formation. In horses, carcinogenesis can be influenced by various factors, including genetic predisposition, environmental exposures, and viral infections. Common types of cancer in horses include squamous cell carcinoma, melanoma, and lymphoma. Research in equine carcinogenesis focuses on understanding the molecular mechanisms underlying these transformations, identifying risk factors, and developing diagnostic and therapeutic strategies. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, risk factors, and clinical implications of carcinogenesis in equine health.
Knowledge and practice of radiation safety in Brazilian equine veterinarians are less than optimal: An online survey. Exposure to ionizing radiation is an occupational risk for veterinarians due to the potential for carcinogenesis, reproductive disorders, cataracts, and hereditary genetic changes. This survey study aimed to identify the radiological protection practices routinely used by veterinarians who work with portable digital X-ray equipment in horses in Brazil and assess their knowledge regarding current legislation. A total of 120 voluntary participation questionnaires were sent to veterinarians who used portable digital radiographic equipment in horses nationwide. The frequencies of the answers were ...
Safety of a feed additive consisting of a tincture derived from the roots of Gentiana lutea L. (gentian tincture) for all animal species (FEFANA asbl). Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety of a tincture derived from L. (gentian tincture). It is intended to be used as a sensory additive for all animal species. The product is a water/ethanol solution, with a dry matter content of approximately 4.3% and it contains on average 0.0836% polyphenols (of which 0.0463% are flavonoids and 0.0027% xanthones) and 0.0022% gentiopicroside. The additive is intended for use in complete feed or drinking water up to a maximum level of 50 mg tincture/kg for all animal species, except ho...
Identification of interspecific differences in phase II reactions: determination of metabolites in the urine of 16 mammalian species exposed to environmental pyrene. Interspecific differences in xenobiotic metabolism are a key to determining relative sensitivities of animals to xenobiotics. However, information on domesticated livestock, companion animals, and captive and free-ranging wildlife is incomplete. The present study evaluated interspecific differences in phase II conjugation using pyrene as a nondestructive biomarker of polycyclic aromatic hydrocarbon (PAH) exposure. Polycyclic aromatic hydrocarbons and their metabolites have carcinogenic and endocrine-disrupting effects in humans and wildlife and can have serious consequences. The authors collec...
The effect of environmental factors on sister chromatid exchange incidence in domestic horse (Equus caballus) chromosomes. The SCE test is often used as a sensitive and reliable technique in the biomonitoring of genotoxicity of mutagenic and carcinogenic agents. This study analysed the frequency of sister chromatid exchange in domestic horse chromosomes depending on the habitat and age of the analysed horses. The chromosome preparations were obtained from an in vitro culture of peripheral blood lymphocytes stained using the FPG technique. Both the habitat and the age significantly influence SCE frequency. A higher SCE incidence was observed in horses that lived in a large urban agglomeration than in those from the...
A biological hazard of our age: bracken fern [Pteridium aquilinum (L.) Kuhn]–a review. Bracken fern (Pteridium aquilinum) is the fifth most distributed common weed species of the world. Its ecological distribution is very wide, and the plant can grow and spread successfully on many types of soil. The cover of P. aquilinum is--in some cases--remarkable (e.g., in the United Kingdom). Bracken fern contains different poisonous agents: some cyanogen glycosides, factors (agents) of antithiamine character (thermolabile thiaminase and thermostable other compounds) and factors of carcinogenic activity (first of all ptaquiloside). This paper summarises and reviews different toxicological ...
Horse heart myoglobin catalyzes the H2O2-dependent oxidative dehalogenation of chlorophenols to DNA-binding radicals and quinones. The heme-containing respiratory protein, myoglobin (Mb), best known for oxygen storage, can exhibit peroxidase-like activity under conditions of oxidative stress. Under such circumstances, the initially formed ferric state can react with H2O2 (or other peroxides) to generate a long-lived ferryl [Fe(IV)=O] Compound II (Cpd II) heme intermediate that is capable of oxidizing a variety of biomolecules. In this study, the ability of Mb Cpd II to catalyze the oxidation of carcinogenic halophenols is demonstrated. Specifically, 2,4,6-trichlorophenol (TCP) is converted to 2,6-dichloro-1,4-benzoquinone...
Discovery and occurrence of the fumonisins: a historical perspective. This article describes the events leading to the discovery of the fumonisins in South Africa in 1988 and highlights the first 10 years (1988-1998) of fumonisin research. The predominant fungus isolated from moldy corn implicated in a field outbreak of equine leukoencephalomalacia (ELEM) in South Africa in 1970 was Fusarium verticillioides (F. moniliforme). This fungus was also prevalent in moldy home-grown corn consumed by people in high-incidence areas of esophageal cancer (EC) in the Transkei region of South Africa. Culture material on corn of F. verticillioides strain MRC 826, which was iso...
Fumonisins, mycotoxins of increasing importance: their nature and their effects. The fumonisins (FBs) are a group of closely related mycotoxins that are prevalent in maize. They were isolated from strains of Fusarium moniliforme (Sheldon), which were implicated in the aetiology of human oesophageal cancer in the Transkei, South Africa. Their discovery explained the cause of equine encephalomalacia, or "hole in the head" syndrome, when it was found by feeding trials in horses that they elicited the disease. Subsequently, they were found to cause hepatic cancer in rats and pulmonary oedema in pigs, with most animal species tested showing liver and kidney damage. FB1 is the m...
Carcinogenicity of dichlorvos. Dichlorvos, 2,2-dichlorovinyl dimethyl phosphate, an organophosphate insecticide, is widely used for the control of agricultural, industrial, and domestic pests (Fig. 1) [1]. Dichlorvos is administered orally as an anthelmintic to swine, horses, cats, and dogs. It is applied by dermal application to cattle, goats, sheep, swine, and chickens to control fleas, flies, and mites. Cucumbers, radishes, lettuce, and tomatoes are treated with dichlorvos in greenhouses. Aerosols and strips are used for the control of ants, bedbugs, ticks, cockroaches, flies, mosquitoes, silverfish, spiders, and wasps. ...