Exhaled ethane and antioxidant vitamin supplements in active smokers.

To determine the effect of nutritional agents on lipid peroxidation, 10 smokers were given 6 mg beta carotene, 200 IU vitamin E, and 250 mg vitamin C 4 times daily for 3 weeks. Lipid peroxidation was assessed by measuring baseline and postsupplementation levels of exhaled ethane. There was a 29% decrease in mean (+/-SD) exhaled ethane (4.06 +/- 1.49 vs 2.90 +/- 1.29 pmol.kg-1.min-1), with individual levels decreasing in 8 of the 10 smokers (p < 0.05, Wilcoxon sign rank test). Three nonsmokers had very low baseline levels of ethane that did not change with supplementation. Ethane production correlated with active (packs per day) and lifelong (pack-years) tobacco consumption. Also, a strong correlation was found between the decline in ethane output after micronutrient supplementation and the presupplement FEV1. Therefore, antioxidant vitamin supplementation resulted in attenuation of smoking-related lipid peroxidation, and the decreases in ethane production appears to be associated with preserved lung function.

Transduction efficiency of cell lines and hematopoietic stem cells correlates with retrovirus receptor mRNA levels.

The low transduction efficiency of hematopoietic stem cells (HSC) using amphotropic retroviruses continues to plague gene therapy protocols. This low transduction efficiency may be related to a low level of amphotropic retrovirus binding to target cell receptors. We have assayed murine and human cell lines as well as primary bone marrow HSC populations for mRNA encoding retrovirus receptors. Total cellular RNA was amplified by reverse transcriptase-polymerase chain reaction and the level of ecotropic and amphotropic receptor mRNA was compared to the level of beta 2-microglobulin mRNA in the same cell populations. Cell lines that are easily transduced by ecotropic and amphotropic retroviruses have high levels of receptor mRNA. In studies using murine HSC-enriched populations obtained from bone marrow, we observed a high correlation between transduction efficiency and the level of ecotropic and amphotropic receptor mRNA. We predict from these findings that purification of monkey and human HSC populations with high levels of amphotropic receptor mRNA will enable us to obtain improved efficiency of gene transfer.