ABSTRACT
【Objective】 To investigate the impact of ceasing mutual blood donation on voluntary blood donation in Guangzhou. 【Methods】 The data of blood donation from July 2016 to December 2019 (42-month before and after the official cease of mutual blood donation) in the Blood Collection and Supply System of Guangzhou Blood Center, including whole blood donations and apheresis platelets donations, were collected for interrupted time series analysis by month. Blood donors who donated (either whole blood or platelets) during 2016 were followed up until December 31, 2019, and the re-donation rate was analyzed by Chi-square test, t test and logistic regression analysis. 【Results】 The results showed that ceasing mutual blood donation had a significantly positive effect on the increase of platelet donations, but had no significant effect on whole blood donation. In 2016, whole blood donations and platelet donations were mainly voluntary (86.4% and 60.8%, respectively). In comparison of voluntary blood donation, the overall blood deferral rate(by dual assays) of mutual blood donation was higher (P<0.01), but the difference diminished as they donated twice or more. The re-donation rate of blood donors (mutual non-remunerated, voluntary, or both) all increased after the ceasing of mutual blood donation (mutual non-remunerated, : 4.7% vs 4.0%, χ2=29.8, P<0.01; voluntary: 24.8% vs 9.9%, χ2=17295.3, P<0.01; both: 36.3% vs 28.1%, χ2=29.3, P<0.01). The re-donation rate of mutual platelet donors decreased after the ceasing of mutual blood donation, but the number of voluntary platelet donors increased. 【Conclusion】 The ceasing of mutual blood donation was in favour of voluntary blood donation in Guangzhou since various means had been previously adopted by Guangzhou Blood Center to create a long-term mechanism of voluntary blood donation. The number of voluntary blood donors has increased, and the clinical use of blood has been further guaranteed.
ABSTRACT
<p><b>OBJECTIVE</b>To study the changes in expression and activity of protein phosphatases type 2A (PP2A ) during differentiation of NB4 and NB4-MR2 cells induced by all-trans retinoic acid (ATRA), and evaluate the role of PP2A in MR2 resistance to ATRA.</p><p><b>METHODS</b>ATRA, okadaic acid (OKA) and ATRA + OKA at the same dosage were incubated with NB4 and MR2 cells respectively. Wright's staining and NBT reduction test were employed to evaluate the change in the cells. The CD11b expression was measured by flow cytometry. The activity of PP2A was evaluated by serine/threonine phosphatase assay system, and the level of PP2A subunits was detected by Western blot.</p><p><b>RESULTS</b>1) Wright's staining, NBT reduction test and flow cytometry results showed OKA could augment the differentiation of NB4 induced by ATRA, and OKA + ATRA induced slight differentiation of MR2 cells. 2) Phosphatase assay showed a decrease in PP2A phosphatase activity [(534 +/- 43) pmol x min(-1) x microg protein(-1)] in NB4 after ATRA treatment, accompanied with that activity [(959 +/- 83) pmol x min(-1) x microg protein(-1)] in untreated NB4 cells. OKA enhanced the inhibitory effect of ATRA on the activity in NB4. When OKA + ATRA was incubated with MR2, PP2A in the cells was significantly decreased [(229 +/- 23) pmol x min(-1) x microg protein(-1)]. 3) Western blot analysis showed that the level of PP2A catalytic subunit (PP2A/C) was decreased during the course of ATRA-induced NB4 cell differentiation, whereas expressions of every subunits of PP2A in MR2 cells were somewhat unaltered.</p><p><b>CONCLUSION</b>Expression of PP2A/C and activity of PP2A is decreased during differentiation of NB4 induced by ATRA, and no repression of the PP2 activity maybe related to MR2 resistance to ATRA.</p>