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Abstract Background Plasma transforming growth factor β1 (TGFβ1 ) levels are elevated in patients with lung cancer. As TGFβ1 is mainly found in platelets and as nonmalignant pulmonary diseases (NMPD) are frequently associated with lung cancer, we investigated the potential contribution of platelet degranulation and/or of a concomitant NMPD to the increased plasma levels of TGFβ1 reported in patients with lung cancer. Materials and Methods Blood samples were collected in duplicate from 30 healthy subjects, 14 patients suffering from NMPD and 37 patients with lung cancer. The platelet count was determined and the samples were processed to obtain plasma. One sample was collected in EDTA (EDTA plasma) and the other in a mixture inhibiting platelet degranulation (PIM plasma). TGFβ1 concentrations and β-thromboglobulin (βTG) levels, an index of platelet degranulation, were measured in both plasma samples. Results TGFβ1 and βTG plasma levels measured in PIM plasma were lower than those obtained in EDTA plasma. With respect to PIM plasma, both TGFβ1 and βTG levels were higher in patients with lung cancer than those with NMPD and in healthy individuals. In patients with NMPD, only TGFβ1 levels were increased as compared to healthy controls, βTG levels being similar. Conclusion Methods for collecting and processing blood samples are critical in determining reliable circulating TGFβ1 levels. Increased TGFβ1 plasma levels observed in patients with lung cancer are related, at least partly, to concomitant NMPD and also to platelet degranulation as proved by increased βTG levels. [ABSTRACT FROM AUTHOR]

The intracellular distribution of thymidine phosphorylating kinases has been studied ill rat liver at different times after partial hepatectomy. After conventional fractionation in 0.25 M sucrose, thymidine kinase is present in all fractions, the highest proportion being found, however, in the supernatant; phosphorylation of thymidine to TDP and TTP is detected only in the supernatant fraction from 24 h onwards after hepatectomy. Nuclei prepared in 2.2 M sucrose or in non-aqueous media have the same level of thymidine kinase activity and can never phosphorylate thymidine to TDP and TTP. In the nuclear fractions, the absolute activity of thymidine kinase increases from 16 to 46 h after hepatectomy but represents a decreasing proportion of the activity of the homogenate. At the same time, the proportion of kinase activity rises markedly in the supernatant fraction with a maximum of 83% in 40 h regenerating livers. The implications of these results are discussed. [ABSTRACT FROM AUTHOR]