James T. Davis

Dietary Antioxidants Protect Hematopoietic Cells and Improve Animal Survival after Total-Body Irradiation

Abstract Wambi, C., Sanzari, J., Wan, X. S., Nuth, M., Davis, J., Ko, Y. H., Sayers, C. M., Baran, M., Ware, J. H. and Kennedy, A. R. Dietary Antioxidants Protect Hematopoietic Cells and Improve Animal Survival after Total-Body Irradiation. Radiat. Res. 169, 384–396 (2008). The purpose of this study was to determine whether a dietary supplement consisting of l-selenomethionine, vitamin C, vitamin E succinate, α-lipoic acid and N-acetyl cysteine could improve the survival of mice after total-body irradiation. Antioxidants significantly increased the 30-day survival of mice after exposure to a potentially lethal dose of X rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 h after 1 Gy and 8 Gy. Antioxidants were effective in preventing peripheral lymphopenia only after low-dose irradiation. Antioxidant supplementation was also associated with increased bone marrow cell counts after irradiation. Supplementation with antioxidants was associated with increased Bcl2 and decreased Bax, caspase 9 and TGF-β1 mRNA expression in the bone marrow after irradiation. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow after sublethal or potentially lethal irradiation. Taken together, oral supplementation with antioxidants appears to be an effective approach for radioprotection of hematopoietic cells and improvement of animal survival, and modulation of apoptosis is implicated as a mechanism for the radioprotection of the hematopoietic system by antioxidants.

Serum Lipids in Breast-Fed Infants and in Infants Fed Evaporated Milk

R ECENT investigations into the role of the lipid components of diets fed human infants have revealed a paucity of data concerning serum lipid patterns in infants fed the foods most commonly used in the United Stateshuman milk and evaporated whole cow’s milk. The purpose of the present study is to document the lipid patterns in infants fed these two diets between birth and six months of age, including as many lipids and lipid-soluble substances as could be readily measured when these studies were begun in 1957. The infants in this study were selected after interviewing mothers in the last trimester of pregnancy in the prenatal clinic at Vanderbilt Hospital and choosing those either planning to nurse their infants or willing to use the evaporated milk provided. Premature infants and twins were excluded from the study as were all infants having any illness other than mild infection of the respiratory tract. The infants were seen regularly in the Well Baby Clinic and in all growth, development and state of health were within the limits of clinical normal.

The Effect of Total-Body X-Irradiation on Fatty Acids of Testes of Rats

The effect of total-body x irradiation on testicular fatty acids was studied. Total fatty acid concentration of testes of animals irradiated as adults, weanlings, or prenatally decreased along with the testicular mass. The major change in fatty acid composition in adult and weanling animals was a decrease in arachidonic acid with irradiation. Other changes included a decrease in palmitic acid with irradiation at 29 and 43 days and increases in stearic and oleic acids. Pentaenoic acids increased with irradiation significantly in one group at 22 and 29 days, followed by decreases at 43 and 62 days postirradiation. No changes were seen in gonadal fatty acid composition of offspring of rats irradiated on the 18th day of pregnancy. (auth)