Pulmonary function abnormalities in thalassemia major and the role of iron overload.

To determine the predominant abnormality of pulmonary function in patients with thalassemia major (TM), we evaluated 29 patients with TM who were receiving hypertransfusion therapy and chelation with desferrioxamine (DFO), and who ranged in age from 6 to 40 yr (mean 19.8 +/- 8.5 yr). A reduction in the total lung capacity (TLC) was the most striking abnormality, found in 21 of 29 patients (79%). Fourteen of these patients (67%) had a moderate or severe reduction in TLC. Expiratory flow rates, FEV1, and FEF25-75 were decreased below predicted values in 48 and 17% of the patients, respectively, but no patients had pure obstructive disease. Significant hypoxemia (oxygen saturation of less than 95%) was observed in only one patient. There was a significant inverse correlation between TLC and patient age (p < 0.003), transfusional iron burden (p < 0.003) and DFO ratio (p < 0.024). Restrictive disease is the predominant abnormality of pulmonary function in TM, with a mixed restrictive-obstructive pattern in a small number of patients. The restrictive disease becomes more severe with increasing age, and the degree and duration of iron overload appear to be important in its pathogenesis. The role of DFO therapy in preventing the pulmonary complications associated with TM requires further study.

[Characteristics of the mutagenic and toxic effects of ethylene imine and its oligomers. Comparative study in the automated SOS-chromotest system and in standard bacterial test systems]. / Zakonomernosti mutagennogo i toksicheskogo deistviia étilenimina i ego oligomerov. Sravnitel'noe izuchenie v avtomatizirovannoi sisteme SOS-khromotest i v standartnykh bakterial'nykh test-sistemakh.

Raising total positive charge of a chemical mutagen does increase its local concentration in the area of biological target-DNA, and, as a consequence, causes increase in the rate of interaction of a mutagen with the target. Experimental evidence of this idea has been obtained in three test systems: the Ames test, Trp+ reversions in Escherichia coli WP2 and in the automated "SOS-chromotest" system with E. coli PQ 37 ("Labsystems", Finland).