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Full-Text Articles in Medicine and Health Sciences
Suppression Of Peroxisomal Enzyme Activities And Cytochrome P450 4a Isozyme Expression By Congeneric Polybrominated And Polychlorinated Biphenyls, Larry W. Robertson, Isabelle Berberian, Tim Borges, Li-Chuan Chen, Ching K. Chow, Howard P. Glauert, Johannes G. Filser, Helmut Thomas
Suppression Of Peroxisomal Enzyme Activities And Cytochrome P450 4a Isozyme Expression By Congeneric Polybrominated And Polychlorinated Biphenyls, Larry W. Robertson, Isabelle Berberian, Tim Borges, Li-Chuan Chen, Ching K. Chow, Howard P. Glauert, Johannes G. Filser, Helmut Thomas
Toxicology and Cancer Biology Faculty Publications
The purpose of this study was to determine the effects of PCBs and PBBs on peroxisome proliferator-activated receptor-alpha-(PPARalpha-) associated enzyme activities or protein levels. Male Sprague-Dawley rats were administered a single IP injection (150 mu mol/kg) of either 3,3',4,4'-tetrabromobiphenyl, 3,3',4,4'-tetrachlorobiphenyl, 3,3',5,5'-tetrabromobiphenyl, 2',3,3',4,5-pentachlorobiphenyl, 3,3',4,4',5-pentachlorobiphenyl, 2,2',3,3',5,5'-hexachlorobiphenyl, or 3,3',4,4',5,5'-hexabromobiphenyl in corn oil (10 ml/kg). One week later, the activities of catalase, peroxisomal fatty acyl-CoA oxidase, and peroxisomal beta-oxidation as well as cytochrome P450 4A (CYP4A) protein content were determined in subcellular liver fractions. None of the peroxisomal enzyme activities were significantly increased by any of the halogenated biphenyl congeners tested. Except for minor …
Replication Fork Regression In Vitro By The Werner Syndrome Protein (Wrn): Holliday Junction Formation, The Effect Of Leading Arm Structure And A Potential Role For Wrn Exonuclease Activity, Amrita Machwe, Liren Xiao, Robert G Lloyd, Edward Bolt, David K. Orren
Replication Fork Regression In Vitro By The Werner Syndrome Protein (Wrn): Holliday Junction Formation, The Effect Of Leading Arm Structure And A Potential Role For Wrn Exonuclease Activity, Amrita Machwe, Liren Xiao, Robert G Lloyd, Edward Bolt, David K. Orren
Toxicology and Cancer Biology Faculty Publications
The premature aging and cancer-prone disease Werner syndrome stems from loss of WRN protein function. WRN deficiency causes replication abnormalities, sensitivity to certain genotoxic agents, genomic instability and early replicative senescence in primary fibroblasts. As a RecQ helicase family member, WRN is a DNA-dependent ATPase and unwinding enzyme, but also possesses strand annealing and exonuclease activities. RecQ helicases are postulated to participate in pathways responding to replication blockage, pathways possibly initiated by fork regression. In this study, a series of model replication fork substrates were used to examine the fork regression capability of WRN. Our results demonstrate that WRN catalyzes …
Identification And Characterization Of Ogg1 Mutations In Patients With Alzheimer's Disease, Guogen Mao, Xiaoyu Pan, Beibei Zhu, Yanbin Zhang, Fenghua Yuan, Jian Huang, Mark A. Lovell, Maxwell P. Lee, William R. Markesbery, Guo-Min Li, Liya Gu
Identification And Characterization Of Ogg1 Mutations In Patients With Alzheimer's Disease, Guogen Mao, Xiaoyu Pan, Beibei Zhu, Yanbin Zhang, Fenghua Yuan, Jian Huang, Mark A. Lovell, Maxwell P. Lee, William R. Markesbery, Guo-Min Li, Liya Gu
Toxicology and Cancer Biology Faculty Publications
Patients with Alzheimer's disease (AD) exhibit higher levels of 8-oxo-guanine (8-oxoG) DNA lesions in their brain, suggesting a reduced or defective 8-oxoG repair. To test this hypothesis, this study investigated 14 AD patients and 10 age-matched controls for mutations of the major 8-oxoG removal gene OGG1. Whereas no alterations were detected in any control samples, four AD patients exhibited mutations in OGG1, two carried a common single base (C796) deletion that alters the carboxyl terminal sequence of OGG1, and the other two had nucleotide alterations leading to single amino acid substitutions. In vitro biochemical assays revealed …