Charles Stephensen

Summary

Affiliation: Agricultural Research Service
Country: USA

Publications

  1. ncbi request reprint Vitamins C and E in adolescents and young adults with HIV infection
    Charles B Stephensen
    US Department of Agriculture Agricultural Research Service, Western Human Nutrition Research Center at the University of California Davis, Davis, CA 95616, USA
    Am J Clin Nutr 83:870-9. 2006
  2. ncbi request reprint Glutathione, glutathione peroxidase, and selenium status in HIV-positive and HIV-negative adolescents and young adults
    Charles B Stephensen
    US Department of Agriculture Agricultural Research Service, Western Human Nutrition Research Center, University of California, Davis, CA 95616, USA
    Am J Clin Nutr 85:173-81. 2007
  3. pmc Disruption of Rxra gene in thymocytes and T lymphocytes modestly alters lymphocyte frequencies, proliferation, survival and T helper type 1/type 2 balance
    Charles B Stephensen
    USDA Western Human Nutrition Research Center and Nutrition Department, University of California, Davis, CA 95616, USA
    Immunology 121:484-98. 2007
  4. ncbi request reprint Fish oil and inflammatory disease: is asthma the next target for n-3 fatty acid supplements?
    Charles B Stephensen
    US Department of Agriculture Western Human Nutrition Research Center and Nutrition Department, University of California, Davis, California, USA
    Nutr Rev 62:486-9. 2004
  5. ncbi request reprint Vitamin D status in adolescents and young adults with HIV infection
    Charles B Stephensen
    US Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center at the University of California, Davis, CA 95616, USA
    Am J Clin Nutr 83:1135-41. 2006
  6. ncbi request reprint Immune activation and oxidative damage in HIV-positive and HIV-negative adolescents
    Charles B Stephensen
    United States Department of Agriculture Western Human Nutrition Research Center and Department of Nutrition, University of California at Davis, Davis, CA 95616, USA
    J Acquir Immune Defic Syndr 38:180-90. 2005
  7. ncbi request reprint Plasma cytokines and oxidative damage in HIV-positive and HIV-negative adolescents and young adults: a protective role for IL-10?
    Charles B Stephensen
    USDA ARS Western Human Nutrition Research Center at the University of California, Davis and Department of Nutrition, University of California, Davis, CA 95616, USA
    Free Radic Res 39:859-64. 2005
  8. ncbi request reprint Vitamin A deficiency increases the in vivo development of IL-10-positive Th2 cells and decreases development of Th1 cells in mice
    Charles B Stephensen
    U S Department of Agriculture, Western Human Nutrition Research Center at the University of California, Davis, and Nutrition Department, University of California, Davis, CA 95616, USA
    J Nutr 134:2660-6. 2004
  9. ncbi request reprint Diets rich in polyphenols and vitamin A inhibit the development of type I autoimmune diabetes in nonobese diabetic mice
    Susan J Zunino
    USDA, Agricultural Research Service, Western Human Nutrition Research Center, University of California, Davis, CA 95616, USA
    J Nutr 137:1216-21. 2007
  10. doi request reprint Vitamin A status is associated with T-cell responses in Bangladeshi men
    Shaikh M Ahmad
    Department of Nutrition, Program in International and Community Nutrition, University of California, Davis, CA, USA
    Br J Nutr 102:797-802. 2009

Research Grants

Detail Information

Publications22

  1. ncbi request reprint Vitamins C and E in adolescents and young adults with HIV infection
    Charles B Stephensen
    US Department of Agriculture Agricultural Research Service, Western Human Nutrition Research Center at the University of California Davis, Davis, CA 95616, USA
    Am J Clin Nutr 83:870-9. 2006
    ..Oxidative stress during HIV infection may impair immune function, cause more rapid disease progression, and increase requirements for dietary antioxidants such as vitamins C and E...
  2. ncbi request reprint Glutathione, glutathione peroxidase, and selenium status in HIV-positive and HIV-negative adolescents and young adults
    Charles B Stephensen
    US Department of Agriculture Agricultural Research Service, Western Human Nutrition Research Center, University of California, Davis, CA 95616, USA
    Am J Clin Nutr 85:173-81. 2007
    ..Antioxidant nutrient deficiencies may hasten the progression of HIV disease by impairing antioxidant defenses...
  3. pmc Disruption of Rxra gene in thymocytes and T lymphocytes modestly alters lymphocyte frequencies, proliferation, survival and T helper type 1/type 2 balance
    Charles B Stephensen
    USDA Western Human Nutrition Research Center and Nutrition Department, University of California, Davis, CA 95616, USA
    Immunology 121:484-98. 2007
    ..These differences were modest in magnitude and their impact on disease resistance is yet to be examined...
  4. ncbi request reprint Fish oil and inflammatory disease: is asthma the next target for n-3 fatty acid supplements?
    Charles B Stephensen
    US Department of Agriculture Western Human Nutrition Research Center and Nutrition Department, University of California, Davis, California, USA
    Nutr Rev 62:486-9. 2004
    ..Such supplements also provide symptomatic relief for rheumatoid arthritis patients. Recent research suggests that asthma, another highly prevalent, chronic inflammatory disease, may also respond to fish oil supplements...
  5. ncbi request reprint Vitamin D status in adolescents and young adults with HIV infection
    Charles B Stephensen
    US Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center at the University of California, Davis, CA 95616, USA
    Am J Clin Nutr 83:1135-41. 2006
    ..Vitamin D status affects immune function and thus may affect the progress of HIV infection...
  6. ncbi request reprint Immune activation and oxidative damage in HIV-positive and HIV-negative adolescents
    Charles B Stephensen
    United States Department of Agriculture Western Human Nutrition Research Center and Department of Nutrition, University of California at Davis, Davis, CA 95616, USA
    J Acquir Immune Defic Syndr 38:180-90. 2005
    ..Plasma ceruloplasmin was associated with decreased oxidative damage in HIV-positive subjects, although this association was not seen in those taking ART...
  7. ncbi request reprint Plasma cytokines and oxidative damage in HIV-positive and HIV-negative adolescents and young adults: a protective role for IL-10?
    Charles B Stephensen
    USDA ARS Western Human Nutrition Research Center at the University of California, Davis and Department of Nutrition, University of California, Davis, CA 95616, USA
    Free Radic Res 39:859-64. 2005
    ..This finding is consistent with a protective role for IL-10 in diminishing oxidative damage during immune activation...
  8. ncbi request reprint Vitamin A deficiency increases the in vivo development of IL-10-positive Th2 cells and decreases development of Th1 cells in mice
    Charles B Stephensen
    U S Department of Agriculture, Western Human Nutrition Research Center at the University of California, Davis, and Nutrition Department, University of California, Davis, CA 95616, USA
    J Nutr 134:2660-6. 2004
    ..4 +/- 0.67 and 47.0 +/- 2.8%, respectively). Thus vitamin A deficiency, at the time of initial antigen exposure, enhances the development of IL-10-producing Th2 or T regulatory cells and diminishes the development of Th1 memory cells...
  9. ncbi request reprint Diets rich in polyphenols and vitamin A inhibit the development of type I autoimmune diabetes in nonobese diabetic mice
    Susan J Zunino
    USDA, Agricultural Research Service, Western Human Nutrition Research Center, University of California, Davis, CA 95616, USA
    J Nutr 137:1216-21. 2007
    ..These data suggest that diets rich in polyphenols or vitamin A have protective effects against autoimmune inflammatory attack of the islet beta cells and have the potential to reduce the onset and pathogenesis of autoimmune diabetes...
  10. doi request reprint Vitamin A status is associated with T-cell responses in Bangladeshi men
    Shaikh M Ahmad
    Department of Nutrition, Program in International and Community Nutrition, University of California, Davis, CA, USA
    Br J Nutr 102:797-802. 2009
    ..These data show that increasing vitamin A stores above the level that maintains normal vision enhances some measures of T-cell-mediated immunity, suggesting a difference in requirements for maintaining vision and immune function...
  11. ncbi request reprint Moderate antioxidant supplementation has no effect on biomarkers of oxidant damage in healthy men with low fruit and vegetable intakes
    Robert A Jacob
    U S Department of Agriculture ARS Western Human Nutrition Research Center, University of California at Davis, 95616 8683, USA
    J Nutr 133:740-3. 2003
    ..In healthy young men, the endogenous antioxidant defense system and a modest intake of dietary antioxidants are adequate to minimize levels of in vivo oxidant damage such that they cannot be differentiated by current methods...
  12. ncbi request reprint Vitamin A deficiency decreases and high dietary vitamin A increases disease severity in the mouse model of asthma
    Gertrud U Schuster
    Nutrition Department, U S Department of Agriculture Western Human Nutrition Research Center, University of California Davis, 430 West Health Science Drive, Davis, CA 95616, USA
    J Immunol 180:1834-42. 2008
    ..These data suggest that excessive intake of vitamin A may increase the risk or severity of asthma in industrialized countries whereas vitamin A deficiency continues to increase mortality from infectious diseases in developing countries...
  13. pmc Markers of innate immune function are associated with vitamin a stores in men
    Shaikh M Ahmad
    Department of Nutrition, University of California, Davis, CA 95616, USA
    J Nutr 139:377-85. 2009
    ..The negative association of stores with serum IL-6 and IL-17 suggests that not all protective responses are similarly enhanced by vitamin A...
  14. ncbi request reprint Vitamin A enhances in vitro Th2 development via retinoid X receptor pathway
    Charles B Stephensen
    U S Department of Agriculture Western Human Nutrition Research Center and Nutrition Department, University of California, Davis, CA 95616, USA
    J Immunol 168:4495-503. 2002
    ..These data show that stimulation of the RXR pathway enhances Th2 development, perhaps by affecting the relative expression of pertinent transcription factors, cytokines, and cytokine receptors...
  15. ncbi request reprint Vitamin A, beta-carotene, and mother-to-child transmission of HIV
    Charles B Stephensen
    USDA Western Human Nutrition Research Center and Nutrition Department, University of California, Davis, CA 95616, USA
    Nutr Rev 61:280-4. 2003
    ..Overall, there is no reduction in either mortality or HIV transmission in two recent studies. Contrary to expectations, one study reported an increased risk of transmission using vitamin A plus beta-carotene supplements...
  16. pmc Vitamin D intake needed to maintain target serum 25-hydroxyvitamin D concentrations in participants with low sun exposure and dark skin pigmentation is substantially higher than current recommendations
    Laura M Hall
    Nutrition Department, University of California, Davis, CA, 95616, USA
    J Nutr 140:542-50. 2010
    ..To achieve 25(OH)D > or =75 nmol/L, we estimate that EA individuals with high sun exposure need 1300 iu/d vitamin D intake in the winter and AA individuals with low sun exposure need 2100-3100 iu/d year-round...
  17. ncbi request reprint Lysine deficiency and feed restriction independently alter cationic amino acid transporter expression in chickens (Gallus gallus domesticus)
    Brooke D Humphrey
    Department of Animal Science, University of California, Davis, CA 95616, USA
    Comp Biochem Physiol A Mol Integr Physiol 143:218-27. 2006
    ..By expressing high affinity CAT isoforms, developing lymphocytes may have a greater ability to obtain lysine than their surrounding tissue during a lysine deficiency...
  18. ncbi request reprint Retinoid x receptor agonists increase bcl2a1 expression and decrease apoptosis of naive T lymphocytes
    Reuven Rasooly
    U S Department of Agriculture USDA Western Human Nutrition Research Center and Nutrition Department, University of California, Davis, CA, 95616, USA
    J Immunol 175:7916-29. 2005
    ..Thus, this effect on Bcl2a1 expression may account for the decreased apoptosis seen in naive T lymphocytes treated with RXR agonists...
  19. pmc Men with low vitamin A stores respond adequately to primary yellow fever and secondary tetanus toxoid vaccination
    Shaikh M Ahmad
    Program in International and Community Nutrition, Department of Nutrition, University of California Davis, CA 95616, USA
    J Nutr 138:2276-83. 2008
    ..084 micromol/g. Such increases may enhance vaccine protection but raise the question of whether immune-mediated chronic diseases may by exacerbated by high-level dietary vitamin A...
  20. pmc Metabolic profiling of major vitamin D metabolites using Diels-Alder derivatization and ultra-performance liquid chromatography-tandem mass spectrometry
    Pavel A Aronov
    Department of Entomology, University of California, Davis, CA, 95616, USA
    Anal Bioanal Chem 391:1917-30. 2008
    ..5 mL human serum at a lower limit of quantification of 25 pg/mL. Precision ranged from 1.6-4.8 % and 5-16 % for 25-hydroxyvitamin D(3) and 1alpha,25-dihydroxyvitamin D(3), respectively, using solid-phase extraction...
  21. ncbi request reprint Commentary: A hypothesis concerning vitamin A supplementation, vaccines, and childhood mortality
    Charles B Stephensen
    USDA Western Human Nutrition Research Center, and Nutrition Department, University of California, Davis, CA 95616 8669, USA
    Int J Epidemiol 32:828-9. 2003
  22. ncbi request reprint Glucose and cationic amino acid transporter expression in growing chickens (Gallus gallus domesticus)
    Brooke D Humphrey
    Department of Animal Science, University of California, 1 Shields Avenue, Davis, CA 95616, USA
    Comp Biochem Physiol A Mol Integr Physiol 138:515-25. 2004
    ..05). The thymus had the lowest high affinity GLUT and total CAT mRNA expression on day 14 posthatch. Therefore, T lymphocytes within the thymus may be most susceptible to glucose and cationic amino acid supply...

Research Grants6

  1. Vitamin A Regulates Th1/Th2 Development via RXR Pathway
    Charles Stephensen; Fiscal Year: 2007
    ..In addition, receptor-selective retinoids are currently used in cancer therapy and are being evaluated for diabetes. This work will help evaluate possible side effects of these therapies. ..
  2. Variation in the ALOX5 gene and response to omega-3 fatty acid supplements
    Charles Stephensen; Fiscal Year: 2007
    ..Indicators of cardiovascular risk will also be assessed before and after intervention, including blood lipid profile, blood pressure, heart rate, and plasma CRP, glucose and insulin concentrations. ..