Protein phosphatase 4 regulates apoptosis in leukemic and primary human T-cells
The control of T-cell survival is of overwhelming importance for preventing leukemia and lymphoma. The present report demonstrates that the serine/threonine protein phosphatase PP4 regulates the survival of both leukemic T-cells and untransformed human peripheral blood T-cells, particularly after treatment with anti-leukemic drugs and other cytotoxic stimuli. PP4-induced apoptosis is mediated, at least in part, through de-phosphorylation of apoptosis regulator PEA-15, previously implicated in the control of leukemic cell survival. PP4 activity significantly affects the mutation rate in leukemic T-cells, indicating that PP4 dysfunction may be important in the development and progression of leukemia.
A recurring problem in forensic medicine is the need to fix the time of death within the limits of probability. Errors in overestimating and underestimating the post-mortem interval based on body cooling is common. Post-mortem biochemistry has become a potent additional procedure in forensic death investigation. However, in our experiment, to determine the post-mortem interval we investigated the ATPase activity. The investigation was performed on the liver tissue of 25 corpses (21 men and four women) of age ranging between 40–60 years. The study of ATPase enzymatic activity shows that there is a considerable drop in the levels of ATPase activity with increasing post-mortem interval up to 24 h and this is one of the most reliable methods for estimating time of death.