Research Topics
Genomes and Genes | Stephen S LeonardSummaryAffiliation: Centers for Disease Control and Prevention Country: USA Publications
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Publications
Particle size-dependent radical generation from wildland fire smokeStephen S Leonard
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
Toxicology 236:103-13. 2007..These results indicate that the radical generation and the damage caused by them is not only a function of surface area but is also influenced by changing chemical and other characteristics due to particle size...- Essiac tea: scavenging of reactive oxygen species and effects on DNA damageStephen S Leonard
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Rd, MS 2015, Morgantown, WV 26505, USA
J Ethnopharmacol 103:288-96. 2006..This study may help to explain the mechanisms behind the reported anti-cancer effects of Essiac... 
Analysis of free-radical scavenging of Yerba Mate (Ilex paraguriensis) using electron spin resonance and radical-induced DNA damageStephen S Leonard
Health Effects Laboratory Div, Natl Inst for Occupational Safety and Health, Morgantown, WV, USA
J Food Sci 75:C14-20. 2010..These data further clarify the reported antioxidant effects of Yerba Mate infusions...- Metal-induced oxidative stress and signal transductionStephen S Leonard
National Institute for Occupational Safety and Health, Pathology and Physiology Research Branch, Health Effects Laboratory Division, 1095 Willowdale Road, MS 2015, Morgantown, WV 26505, USA
Free Radic Biol Med 37:1921-42. 2004.... - Metal-induced toxicity, carcinogenesis, mechanisms and cellular responsesStephen S Leonard
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Mol Cell Biochem 255:3-10. 2004..This article reviews some of the novel information presented at the conference and discusses future avenues of research in this field... - Resveratrol scavenges reactive oxygen species and effects radical-induced cellular responsesStephen S Leonard
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
Biochem Biophys Res Commun 309:1017-26. 2003..Resveratrol was also found to have a significant inhibitory effect on the NF-kappaB signaling pathway after cellular exposure to metal-induced radicals. It was concluded that resveratrol in foods plays an important antioxidant role... 
Comparison of stainless and mild steel welding fumes in generation of reactive oxygen speciesStephen S Leonard
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
Part Fibre Toxicol 7:32. 2010..An inhalation exposure chamber located at NIOSH was used to collect the welding fume particles...- p38 Signaling-mediated hypoxia-inducible factor 1alpha and vascular endothelial growth factor induction by Cr(VI) in DU145 human prostate carcinoma cellsNing Gao
Mary Babb Randolph Cancer Center, Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, West Virginia 26506 9300, USA
J Biol Chem 277:45041-8. 2002..These results suggest that the expression of HIF-1 and VEGF induced by Cr(VI) may be an important signaling pathway in the Cr(VI)-induced carcinogenesis... - Role of reactive oxygen species and MAPKs in vanadate-induced G(2)/M phase arrestZhuo Zhang
Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Free Radic Biol Med 34:1333-42. 2003..Specific ROS affect different MAPK family members and cell growth regulatory proteins with different potencies... - Blackberry extracts inhibit activating protein 1 activation and cell transformation by perturbing the mitogenic signaling pathwayRentian Feng
Pathology and Physiology Research Branch, Helath Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Nutr Cancer 50:80-9. 2004.... - Effects of welding fumes of differing composition and solubility on free radical production and acute lung injury and inflammation in ratsMichael D Taylor
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA
Toxicol Sci 75:181-91. 2003..Additionally, both the soluble and insoluble fractions of the MMA-SS fume were required to produce most effects, indicating that the responses are not dependent exclusively on the soluble metals... - Effect of stainless steel manual metal arc welding fume on free radical production, DNA damage, and apoptosis inductionJames M Antonini
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA
Mol Cell Biochem 279:17-23. 2005..A more comprehensive in vivo animal study is ongoing in the laboratory that is continuing these experiments to try to elucidate the potential mechanisms that may be involved with welding fume-induced lung disease... - DNA double-strand breaks by asbestos, silica, and titanium dioxide: possible biomarker of carcinogenic potential?Zola Msiska
Pathology and Physiology Research Branch, Health Effects Laboratory Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
Am J Respir Cell Mol Biol 43:210-9. 2010..The results of this study indicate that crocidolite has a greater carcinogenic potential than silica and TiO(2), judged by its ability to cause sustained genomic instability in normal lung cells... - Comparison of free radical generation by pre- and post-sintered cemented carbide particlesAleksandr B Stefaniak
National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
J Occup Environ Hyg 7:23-34. 2010..Improved understanding of particle surface chemistry elucidated the importance of biologically active surface area in generation of ROS by particle mixtures... - Metal composition and solubility determine lung toxicity induced by residual oil fly ash collected from different sites within a power plantJames M Antonini
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Mol Cell Biochem 255:257-65. 2004..These results are most likely due to differences in metal composition and solubility of the ROFA samples... - Arsenite induces HIF-1alpha and VEGF through PI3K, Akt and reactive oxygen species in DU145 human prostate carcinoma cellsNing Gao
Mary Babb Randolph Cancer Center, Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506, USA
Mol Cell Biochem 255:33-45. 2004..These data indicate that the arsenite-induced activation of PI3K/Akt signaling and the expression of HIF-1 and VEGF through the generation of ROS could be an important mechanism in the arsenite-induced carcinogenesis... - PbCrO4 mediates cellular responses via reactive oxygen speciesStephen S Leonard
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Mol Cell Biochem 255:171-9. 2004..These particles could induce chronic production of ROS and activation of NF-kappaB and AP-1. Such induction of transcription pathways may be involved in the inflammatory and carcinogenic responses induced by Cr(VI)-containing particles... - Intratracheal amiodarone administration to F344 rats directly damages lung airway and parenchymal cellsMichael D Taylor
Department of Pharmacology and Toxicology, West Virginia University, Morgantown, WV 26506, USA
Toxicol Appl Pharmacol 188:92-103. 2003..t. AD treatment are similar to the mechanisms that underlie human AIPT. Therefore these data suggest that investigators should use caution in extrapolating results from animal studies that utilize i.t. administration of AD to human AIPT... - Differential role of hydrogen peroxide in UV-induced signal transductionMin Ding
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA
Mol Cell Biochem 234:81-90. 2002..radical scavenger) did not inhibit any of these pathways. These results demonstrate that H2O2 generation is required for UV-induced phosphorylation of Akt and p70(S6k), and involved in activation of JNKs and p38 kinase, but not Erks... - As(III) transcriptionally activates the gadd45a gene via the formation of H2O2Jacquelyn J Bower
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Free Radic Biol Med 41:285-94. 2006..In addition, this transcriptional induction was abrogated in the presence of H2O2 scavengers, suggesting a role for H2O2 in the transcriptional control of the gadd45a gene through a Fenton-like free radical mechanism... - Free radical scavenging, DNA protection, and inhibition of lipid peroxidation mediated by uric acidBeth Stinefelt
Division of Animal and Veterinary Science, West Virginia University, Morgantown, West Virginia 26506, USA
Ann Clin Lab Sci 35:37-45. 2005..These results indicate specific antioxidant protection that UA may afford birds against ROS-mediated damage... - Toxicological evaluation of lung responses after intratracheal exposure to non-dispersed titanium dioxide nanorodsJenny R Roberts
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA
J Toxicol Environ Health A 74:790-810. 2011..To summarize, non-dispersed TiO₂ nanorods were found to induce radical formation and cellular oxidant production, and to generate transient and reversible pneumotoxic effects, and to not markedly alter pulmonary immune function... - S-nitrosylation of Bcl-2 inhibits its ubiquitin-proteasomal degradation. A novel antiapoptotic mechanism that suppresses apoptosisNeelam Azad
Department of Pharmaceutical Sciences, West Virginia University, Morgantown, West Virginia 26506, USA
J Biol Chem 281:34124-34. 2006..These findings indicate a novel function of NO and its regulation of Bcl-2, which provides a key mechanism for the control of apoptotic cell death and cancer development... - Hydrogen peroxide formation and actin filament reorganization by Cdc42 are essential for ethanol-induced in vitro angiogenesisYong Qian
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Nihon Arukoru Yakubutsu Igakkai Zasshi 42:605-9. 2007 - Role of metal-induced reactive oxygen species generation in lung responses caused by residual oil fly ashAnthony B Lewis
Department of Safety and Environmental Management, College of Engineering and Mineral Resources, Morgantown, WV 26506, USA
J Biosci 28:13-8. 2003..particulate forms. ROS generated by ROFA-sol. as measured by ESR appear not to play a major role in the lung injury caused after ROFA exposure... - Antioxidant properties of fruit and vegetable juices: more to the story than ascorbic acidStephen S Leonard
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA
Ann Clin Lab Sci 32:193-200. 2002..It appears that consumption of whole fruits and vegetables would be superior to an ascorbic acid supplement for antioxidant effectiveness... - Conference overview: molecular mechanisms of metal toxicity and carcinogenesisJacquelyn J Bower
Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505-2888, USA
Mol Cell Biochem 279:3-15. 2005..Here we highlight some of the research presented, and summarize the conference proceedings... - Mitochondrial superoxide mediates doxorubicin-induced keratinocyte apoptosis through oxidative modification of ERK and Bcl-2 ubiquitinationSudjit Luanpitpong
Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506, USA
Biochem Pharmacol 83:1643-54. 2012.... - Vanadate-induced expression of hypoxia-inducible factor 1 alpha and vascular endothelial growth factor through phosphatidylinositol 3-kinase/Akt pathway and reactive oxygen speciesNing Gao
Mary Babb Randolph Cancer Center, Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, West Virginia 26506-9300, USA
J Biol Chem 277:31963-71. 2002..These results suggest that the expression of HIF-1 and VEGF induced by vanadate through PI3K/Akt may be an important signaling pathway in the vanadate-induced carcinogenesis, and ROS may play an important role... - Overexpression of ErbB2 enhances ethanol-stimulated intracellular signaling and invasion of human mammary epithelial and breast cancer cells in vitroCuiling Ma
Department of Microbiology, Immunology and Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506, USA
Oncogene 22:5281-90. 2003..Our study suggests that overexpression of ErbB2 may augment ethanol-elicited signaling and promote ethanol-stimulated tumor metastasis... - Generation of reactive oxygen species in the enzymatic reduction of PbCrO4 and related DNA damageStephen S Leonard
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Mol Cell Biochem 234:309-15. 2002..OH radicals. The mechanism of .OH generation involves reduction of molecular oxygen to H2O2, which generates .OH radicals through a Fenton-like reaction. The .OH radicals generated by PbCrO4 caused DNA strand breakage... - Role of reactive oxygen species and Cr(VI) in Ras-mediated signal transductionSuwei Wang
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Mol Cell Biochem 255:119-27. 2004..c) Among these reactive species, (.)OH radical is responsible for the further transduction of signals from Ras to the nucleus, leading to various cell responses... - The role of p53 in silica-induced cellular and molecular responses associated with carcinogenesisMaureen R Gwinn
National Institute for Occupational Safety and Health, Health Effects Laboratory Division, Morgantown, West Virginia, USA
J Toxicol Environ Health A 72:1509-19. 2009..These results suggest that altered and deficient p53 affects the cellular response to freshly fractured silica exposure, and thereby enhances susceptibility and augments cell proliferation and lung cancer development... - Cardiovascular effects of pulmonary exposure to single-wall carbon nanotubesZheng Li
Toxicology and Molecular Biology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Environ Health Perspect 115:377-82. 2007..Engineered nanosized materials, such as single-wall carbon nanotubes (SWCNT), are emerging as technologically important in different industries... - In vivo bioassays of acute asbestosis and its correlation with ESR spectroscopy and imaging in redox statusStephen S Leonard
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505-2888, USA
Mol Cell Biochem 234:369-77. 2002.... - Arsenite-induced Cdc25C degradation is through the KEN-box and ubiquitin-proteasome pathwayFei Chen
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, USA
Proc Natl Acad Sci U S A 99:1990-5. 2002.... - Hydrogen peroxide formation and actin filament reorganization by Cdc42 are essential for ethanol-induced in vitro angiogenesisYong Qian
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
J Biol Chem 278:16189-97. 2003..Taken together, our results suggest that ethanol stimulation can induce H(2)O(2) production through the activation of Cdc42, which results in reorganizing actin filaments and increasing cell motility and in vitro angiogenesis... - Inhibition of xanthine oxidase reduces oxidative stress and improves skeletal muscle function in response to electrically stimulated isometric contractions in aged miceMichael J Ryan
Laboratory of Muscle Biology and Sarcopenia, Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, USA
Free Radic Biol Med 51:38-52. 2011.... - Glutathione conjugation of busulfan produces a hydroxyl radical-trapping dehydroalanine metaboliteCody J Peer
Department of Basic Pharmaceutical Sciences and Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, WV, USA
Xenobiotica 42:1170-7. 2012.... - Diabetic cardiomyopathy-associated dysfunction in spatially distinct mitochondrial subpopulationsErinne R Dabkowski
Division of Exercise Physiology, Center for Interdisciplinary Research in Cardiovascular Sciences, West Virginia University School of Medicine, Morgantown, WV, USA
Am J Physiol Heart Circ Physiol 296:H359-69. 2009.... - Urate oxidase knockdown decreases oxidative stress in a murine hepatic cell lineBeth M Cleveland
Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, WV 26506, USA
Oxid Med Cell Longev 2:93-8. 2009..05), but not cells with UOX knockdown, after treatment with SIN-1. These results are consistent with an increased intracellular uric acid concentration and an increased defense against oxidative stress... - Systematic analysis of multiwalled carbon nanotube-induced cellular signaling and gene expression in human small airway epithelial cellsBrandi N Snyder-Talkington
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505
Toxicol Sci 133:79-89. 2013..Gene expression data derived from MWCNT exposure provide information that may be used to elucidate the underlying mode of action of MWCNT in the small airway and suggest potential prognostic gene signatures for risk assessment... - Activation of JNK by vanadate induces a Fas-associated death domain (FADD)-dependent death of cerebellar granule progenitors in vitroJia Luo
Department of Microbiology, Immunology and Cell Biology, West Virginia University School of Medicine, Robert C Byrd Health Science Center, Morgantown, West Virginia 26506, USA
J Biol Chem 278:4542-51. 2003..Thus, JNK signaling plays a major role in vanadate-mediated activation of the Fas-FADD-caspase-8 pathway that accounts for vanadate-induced apoptosis of CGPs... - Shape-enhanced photocatalytic activity of single-crystalline anatase TiO(2) (101) nanobeltsNianqiang Wu
Department of Mechanical and Aerospace Engineering, WVNano Initiative, West Virginia University, Morgantown, West Virginia 26506 6106, USA
J Am Chem Soc 132:6679-85. 2010.... - Protective roles of NF-kappa B for chromium(VI)-induced cytotoxicity is revealed by expression of Ikappa B kinase-beta mutantFei Chen
Health Effects Laboratory Division, NIOSH, Morgantown, West Virginia 26505, USA
J Biol Chem 277:3342-9. 2002..Such inhibition may involve up-regulation of the expression of anti-death proteins including cIAP1 that prevents spontaneous caspase activation and subsequent cleavage of Bcl-xL protein... - Cadmium inhibits the electron transfer chain and induces reactive oxygen speciesYudong Wang
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Free Radic Biol Med 36:1434-43. 2004..The semiubiquinones, being unstable, are prone to transfer one electron to molecular oxygen to form superoxide, providing a possible mechanism for Cd-induced generation of ROS in mitochondria... - Characteristics of dusts encountered during the production of cemented tungsten carbidesAleksandr B Stefaniak
Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA
Ind Health 45:793-803. 2007..Variability in aerosol respirability and chemical heterogeneity could translate into differences in toxicity and support detailed characterization of physicochemical properties during exposure assessments... - Comparison of low doses of aged and freshly fractured silica on pulmonary inflammation and damage in the ratDale W Porter
Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, National Institutes of Health, 1095 Willowdale Road, M S 2015, Morgantown, WV 26505, USA
Toxicology 175:63-71. 2002....