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The relationship between running velocity and heart rate has been determined in 320 runners. A deflection from the expected linearity of this relationship has been observed at sub-maximal running speeds. Deflection velocity and anaerobic threshold (established through blood lactate determination) were coincident in 10 runners, thus showing that the increase in running speed exceeding the augmentation in heart frequency above Vd depends on anaerobic ATP production.

5 Azacytidine ribonucleoside (5 Aza CR), greatly enhances erythroid differentiation of the K562(h) cell line, with a sharp increase of embryonic and fetal globin gene expression. This phenomenon is correlated with the undermethylation of gamma-globin but not of epsilon-globin, as the epsilon-globin gene is already extensively undermethylated before 5AzaCR induction. By contrast no variations in both DNA methylation and expression are observed in 7SL RNA genes.

mRNA-cDNA hybridization, intact reticulocytes biosynthesis and heterologous cell-free translation studies have been performed in cases of heterozygous beta and delta beta thalassaemia. Results obtained have shown that the relative amount of beta mRNA is higher in Ferrara microcytes than in other heterozygous including delta beta. This indicates that transcription of beta globin gene takes place in Ferrara beta 0 thalassaemia. On the contrary globin biosynthesis studies have failed to show clear-cut differences among the various heterozygous considered and cannot evaluate the translatability of beta thal. FemRNA.

Relative alpha and beta chain synthesis in erythroid bursts derived from human bone marrow and peripheral blood are presented. The biosynthetic ratios obtained are compared with those of the reticulocytes. The data obtained cell culture are similar to the "in vivo" ones, showing and alpha/beta ratio of 1 in normal individuals and higher than 1 in beta thalassemic heterozygous. The use of erythroid cell culture as an experimental model for the study of differentiation at molecular level is therefore possible.

The effect of a carbohydrate loading diet on the endurance of six male marathon runners have been examined. Endurance improved in three runners, remained unchanged in two, and worsened in one. Due to the possibility of negative effects on the performance capability, a runner should experiment his personal reactions to the carbohydrate loading diet before using it regularly for long distance competitions.

A library of genomic DNA was prepared from a patient with beta o Ferrara thalassaemia: random human DNA fragments (15 - 20 Kb) have been joined to phage lambda vectors and cloned has viable phage particles (4). 4x10(5) phages have been screened for their content in beta globin gene sequences, using a human beta cDNA plasmid (5) as hybridization probe. Five positive clones have been isolated and characterized by restriction endonuclease cleavage analysis and by the hybridization experiments. The results obtained allow the precise localization of the human fragments inside the beta like globin gene cluster (6). The comparison of the thalassaemic fragments with the normal DNA (6 - 7) shows two different restriction endonuclease sites, for Xba I and Eco RI respectively, downstream from the human beta globin gene.

We studied the relationship between heme accumulation and globin synthesis in human erythroid precursors which were stimulated by 2 I.U. of erythropoietin in semi-solid cultures (1% methyl-cellulose, 20% fetal calf serum) and treated with 6-9 micrograms/ml of desferrioxamina (DF), a potent inhibitor of heme synthesis (6). Heme accumulation was detected by specific reaction with benzidine (4), globin synthesis by CM-cellulose column chromatography. Our results demonstrate that globin gene expression occurs in DF-treated erythroid cells which do not accumulate heme molecules. As heme does affect translation and stability of globin mRNA (10) our system might be suitable for studies focused on pathological alterations of erythropoiesis associated with the presence of unstable globin mRNAs and/or unstable globins.