Normal alveolar epithelial lining fluid contains high levels of glutathione

The epithelial cells on the alveolar surface of the human lower respiratory tract are vulnerable to toxic oxidants derived from inhaled pollutants or inflammatory cells. Although these lung cells have intracellular antioxidants, these defenses may be insufficient to protect the epithelial surface against oxidants present at the alveolar surface. This study demonstrates that the epithelial lining fluid (ELF) of the lower respiratory tract contains large amounts of the sulfhydryl-containing antioxidant glutathione (GSH). The total glutathione (the reduced form GSH and the disulfide GSSG) concentration of normal ELF was 140-fold higher than that in plasma of the same individuals, and 96% of the glutathione in ELF was in the reduced form. Compared with nonsmokers, cigarette smokers had 80% higher levels of ELF total glutathione, 98% of which was in the reduced form. Studies of cultured lung epithelial cells and fibroblasts demonstrated that these concentrations of reduced glutathione were sufficient to protect these cells against the burden of H2O2 in the range released by alveolar macrophages removed from the lower respiratory tract of nonsmokers and smokers, respectively, suggesting that the glutathione present in the alveolar ELF of normal individuals likely contributes to the protective screen against oxidants in the extracellular milieu of the lower respiratory tract.     

Deformability of thawed erythrocytes: introduction of a new preservative solution

Recently, KANE et al. (Centre de Transfusion Sanguine, Strasbourg) designed an original preservative medium, called ESOC, allowing a prolonged storage of thawed RBC. We studied on 15 days the evolution of thawed RBC deformability, while RBC where kept preserved, on the one hand in this ESOC solution, on the other hand in physiologic water, without any preservative medium. We tried to correlate this rheological evolution with cellular ATP, cellular 2,3-DPG and membrane proteins evolution. Deformability was measured by filterability with an Hemorheometre. The results are given as a rigidity index, IR. In ESOC, IR and cellular ATP stay in normal values during the 15 days. In physiologic water, deformability decreases strongly and IR is out of normal values after the fifth day. Cellular ATP decreases out of normal values as soon as the third day. 2,3-DPG decreases in both media. Membrane proteins electrophoresis does not show any difference neither in ESOC nor in physiological water, all fifteen days long. We only observed parallelism between deformability and cellular ATP and IR was higher than normal values. We found no correlation between deformability and 2,3-DPG. We also can conclude, with this study, that ESOC allows a good preservation of thawed RBC and by this way complies with the needs for delayed transfusion in current practice.     

Viral inactivation in blood and red cell concentrates with benzoporphyrin derivative.

Using both the vesicular stomatitis virus (VSV) and feline leukemia virus (FeLV) as models we have shown that the photosensitizer benzoporphyrin derivative ring A (BPD), when activated with red light (600-700 nm), is effective in eliminating both free virus and virally infected cells from spiked blood products and whole blood drawn from viremic cats experimentally infected with FeLV, under conditions which appear to share red blood cells. The effect of photodynamic therapy on infected lymphocytes, as visualized by scanning electron microscopy, initially appeared as a limited area of tiny holes in the membrane. These holes were subsequently seen to increase in size until the membrane appeared completely decomposed. The red cell membranes however, seem to be undamaged by such photodynamic treatment.