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Author (up) Wells, P.G.; Bhuller, Y.; Chen, C.S.; Jeng, W.; Kasapinovic, S.; Kennedy, J.C.; Kim, P.M.; Laposa, R.R.; McCallum, G.P.; Nicol, C.J.; Parman, T.; Wiley, M.J.; Wong, A.W.
Title Molecular and biochemical mechanisms in teratogenesis involving reactive oxygen species Type Journal Article
Year 2005 Publication Toxicology and applied pharmacology Abbreviated Journal Toxicol Appl Pharmacol
Volume 207 Issue 2 Suppl Pages 354-366
Keywords
Abstract Developmental pathologies may result from endogenous or xenobiotic-enhanced formation of reactive oxygen species (ROS), which oxidatively damage cellular macromolecules and/or alter signal transduction. This minireview focuses upon several model drugs (phenytoin, thalidomide, methamphetamine), environmental chemicals (benzo[a]pyrene) and gamma irradiation to examine this hypothesis in vivo and in embryo culture using mouse, rat and rabbit models. Embryonic prostaglandin H synthases (PHSs) and lipoxygenases bioactivate xenobiotics to free radical intermediates that initiate ROS formation, resulting in oxidation of proteins, lipids and DNA. Oxidative DNA damage and embryopathies are reduced in PHS knockout mice, and in mice treated with PHS inhibitors, antioxidative enzymes, antioxidants and free radical trapping agents. Thalidomide causes embryonic DNA oxidation in susceptible (rabbit) but not resistant (mouse) species. Embryopathies are increased in mutant mice deficient in the antioxidative enzyme glucose-6-phosphate dehydrogenase (G6PD), or by glutathione (GSH) depletion, or inhibition of GSH peroxidase or GSH reductase. Inducible nitric oxide synthase knockout mice are partially protected. Inhibition of Ras or NF-kB pathways reduces embryopathies, implicating ROS-mediated signal transduction. Atm and p53 knockout mice deficient in DNA damage response/repair are more susceptible to xenobiotic or radiation embryopathies, suggesting a teratological role for DNA damage, consistent with enhanced susceptibility to methamphetamine in ogg1 knockout mice with deficient repair of oxidative DNA damage. Even endogenous embryonic oxidative stress carries a risk, since untreated G6PD- or ATM-deficient mice have increased embryopathies. Thus, embryonic processes regulating the balance of ROS formation, oxidative DNA damage and repair, and ROS-mediated signal transduction may be important determinants of teratological risk.
Address Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada; Department of Pharmacology, University of Toronto, Toronto, Ontario, Canada
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0041-008X ISBN Medium
Area Expedition Conference
Notes PMID:16081118 Approved no
Call Number refbase @ user @ Serial 68
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Author (up) Wilkins, L.J.; Brown, S.N.; Zimmerman, P.H.; Leeb, C.; Nicol, C.J.
Title Investigation of palpation as a method for determining the prevalence of keel and furculum damage in laying hens Type Journal Article
Year 2004 Publication The Veterinary record Abbreviated Journal Vet. Rec.
Volume 155 Issue 18 Pages 547-549
Keywords Animal Husbandry/methods; Animal Welfare; Animals; Bone and Bones/*injuries; Chickens/*injuries; Female; Fractures, Bone/diagnosis/epidemiology/*veterinary; Great Britain/epidemiology; Housing, Animal/standards; Oviposition; Palpation/methods/*veterinary; Poultry Diseases/*diagnosis/epidemiology; Prevalence; Sensitivity and Specificity
Abstract Old breaks of the keel and furculum were identified by palpation in 500 end-of-lay hens from 10 flocks housed in free-range and barn systems, and the results were compared with the results obtained by a full dissection and inspection. The method was considered to be sufficiently precise to be used as a diagnostic tool although people using it would need to be trained. The results obtained by dissection indicated that 50 to 78 per cent of the birds in the flocks had breaks of the furculum and keel, but no other breaks of bones were detected.
Address Department of Clinical Veterinary Science, University of Bristol, Bristol BS40 5DU
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0042-4900 ISBN Medium
Area Expedition Conference
Notes PMID:15559420 Approved no
Call Number refbase @ user @ Serial 70
Permanent link to this record