Summary:In patients undergoing bone marrow transplant (BMT), reactive oxygen species (ROS) are released as a consequence of the events related to the preparative regimen. Total body irradiation (TBI), which is known to generate ROS, is a routine preconditioning procedure prior to BMT. Several studies have demonstrated that amifostine protects normal tissues. In the present report, we investigated the oxidative state of plasma and erythrocytes in 21 patients with hematological malignancies undergoing TBI. The dose fraction was 160 cGy, twice daily (eight sessions). For ROS detection, we used electron spin resonance spectroscopy and spin-trapping technique. In all, 15 patients received amifostine prior to the irradiation and six did not. No free radical signal was detected in the plasma samples spectrum of 15 amifostinetreated patients, and five of six samples of nontreated patients showed ROS signal. Only two of 15 treated patients had mucositis degree higher than 2, whereas five of six nontreated patients suffered this complication. The average hospitalization days in treated and nontreated patients were 23.5 and 29.7, respectively. This work represents an original observation; we found by direct measurements of free radicals that ROS are released during TBI, and confirmed the amifostine radical scavenger activity.

The present work compares and correlates antioxidant defenses and oxidative stress markers in patients with Diabetes Mellitus (DM) and in those with Rheumatoid Arthritis (RA) in order to find out if new evidences for a possible relationship between these pathologies can be found. Stress markers and antioxidant defenses were tested in blood samples from RA, Type I and Type II DM patients. Erythrocytes (RBC) showed increased susceptibility to lipid peroxidation in both DM and RA, whereas basal oxidation was higher only in RA. Both pathologies showed elevated oxidized LDL concentration and decreased RBC membrane fluidity. In DM, plasma TRAP was decreased and showed an inverse correlation RBC oxidative damage. On the other hand, TRAP was normal in RA. In both pathologies, TRAP was not correlated with oxidized LDL. We can conclude that the peroxidative damage would occur through a complex mechanism, with different factors involved in both illnesses. In this way, an association between these diseases could not be established.

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