BACKGROUND:Buffy-coat-derived platelet concentrates and plasma-rich platelet concentrates have a high incidence of invalid infusion and adverse reactions.
OBJECTIVE:To observe the improved preparation of buffy-coat-derived platelet concentrates and to analyze the influential factors relevant to platelet recovery.
METHODS:400 mL of blood sample extracted from 126 cases were randomly divided into improved buffy-coat group, buffer-coat group and platelet-rich plasma after 4-6 hours. The 3-step centrifugal method was used for improved preparation of buffy-coat-derived platelet concentrates:step 1, centrifugation at 2 300 r/min for 12 minutes at (22±2)℃ with a deceleration of 5;step 2, centrifugation at 910 r/min for 10 minutes at (22±2)℃;step 3, centrifugation at 2 800 r/min for 12 minutes at (22±2)℃. After centrifugation, the upper layer containing few platelets was removed, and the rest 30 mL platelet suspension was platelet concentrates. Factors affecting platelet recovery were analyzed through literature retrieval.
RESULTS AND CONCLUSION:There was no difference in platelet number among the three groups before preparation of platelet concentrates (P>0.05). A higher rate of platelet recovery was found in the platelet-rich plasma group and improved buffy-coat group compared with the buffy-coat group (P<0.05), but there was no difference between the former two groups (P>0.05). There were less residual red blood cells and white blood cells in the two buffy-coat groups than the platelet-rich plasma group (P<0.05), but there was no difference between the two buffy-coat groups (P>0.05). The recovery rate of prepared platelet concentrates was affected by the whole blood amount, centrifugal speed, centrifugation time and methods. Improved buffy-coat method for preparation of platelet concentrates can be generalized in blood centers or blood stations, because it can reduce residual red blood cells and white blood cells and increase rate of platelet recovery.

Objective To establish a scientific and rational narrative medical curriculum standards for clinical medicine postgraduates to improve their medical humanistic quality.Methods On the basis of literature review and group discussion,the standards of narrative medical curriculum for postgraduates majoring in clinical medicine were preliminarily constructed,and the Delphi method was used to evaluate and screen the indicators.An expert consultation questionnaire was drawn up for 40 selected experts to finalize the curriculum standards for narrative medicine.The small-scale teaching practice was carried out in postgraduates of the Department of Hepatobiliary Surgery in Southwest Hospital of Chongqing,and the problems in the process of teaching implementation were collected.Results Experts' opinions tended to be consistent after two rounds of consultation.Finally,the study confirmed a theoretical and practical narrative medical curriculum which consisted of introducing narrative medicine theory,reading narrative medicine related books,watching the medical narrative film and television works,and writing the narrative medical records.Through the small-scale teaching practice,we collected a variety of problems,for which,we sorted out and analyzed,and finally put forward the improvement scheme.Conclusion The narrative medical curriculum for clinical medicine postgraduates is reasonable,which can lay the foundation for the promotion of clinical medical postgraduates' medical humanistic quality and doctor-patient communication ability,and accelerate the popularization of narrative medicine idea in our country.

【Objective】 To investigate the feasibility of differentiation of human AB plasma hematopoietic stem/progenitor cells (HSCs/HPCs) from peripheral blood into mature erythrocytes. 【Methods】 Hematopoietic stem/progenitor cells were induced to be differentiated into mature erythrocytes in the medium supplemented with 5% FBS, 3% FBS + 2% human AB plasma and 8% human AB plasma, respectively, and inoculated in 24-well culture plate at the density of 1×10⁶/mL. Cell proliferation and morphological changes were observed in three different groups. Flow cytometry was used to detect erythroid terminal differentiation markers, i. e. GPA, Band3 and α4(α4-integrin), and late erythroid cell enucleation in different group. The effects of different culture conditions on HSCs/HPCs differentiation into mature erythrocytes were compared. 【Results】 The cell growth and proliferation multiples of the three groups (8% human AB plasma, 5% FBS and 3% FBS+ 2% human AB plasma) were 2 573±116 vs 2 514±246 vs 2 539±119(P>0.05), respectively. The morphological changes of the three groups were similar. With the extension of culture time, the cells differentiated from proerythroblasts to basophils, polychromatic erythroblasts and positive erythroblasts, and almost all of them differentiated into erythrocytes enucleation on day 21. GPA expression and enucleation rate(%) of the three groups were 97.17±1.91 vs 94.95±1.61 vs 96.15±1.38, and 85.1±3.26 vs 86.93±5.96 vs 86.5±3.36(P>0.05), respectively. 【Conclusion】 The differentiation of HSCs/HPCs from peripheral blood plasma into mature erythrocytes from human AB was similar to that of fetal bovine serum.

【Objective】 To investigate the feasibility of leucocyte-reduced pooled platelet concentrates from whole blood stored at 4℃, and provide theoretical basis for the components preparation. 【Methods】 The collected 400 mL ACD-B anticoagulant whole blood was randomly divided into two groups, stored at 4℃ and room temperature. The buffy coat was prepared within 6 hours and store at 22℃ until next day to prepare leucocyte-reduced pooled platelet concentrates. Platelet samples on day 1, 3, 5 and 7 were taken for the blood cell count and related parameter detection. The pH, glucose and lactic acid content were determined to reflect the metabolic status, and the thromboelastography, platelet aggregation rate and PAC-1 and CD62P expression were determined to reflect the function and activation of platelets. The difference in platelets between two groups were analyzed. 【Results】 With the extension of storage time, the count of leucocyte-reduced pooled platelet concentrates decreased gradually, but the platelets distribution width (PDW), mean platelet volume (MPV) and platelet-larger cell ratio (P-LCR) increased gradually in two groups, with no statistical significance (P>0.05).The pH and glucose contents in two groups gradually decreased, but the lactic acid content gradually increased, with no significant difference (P>0.05). The thrombelastogram showed MA value that reflecting platelet function has no significant change during the storage, and there was no significant difference between the two groups (P>0.05). The aggregation rates decreased while the expression of PAC-1 and CD62P increased gradually with the prolongation of preservation time, with no significant difference between the two groups (P>0.05). 【Conclusion】 There is no significant difference in platelet count, function and activation between whole blood stored at 4℃ and at room temperature within 6 hours. Whole blood stored at 4℃ within 6 hours can be considered as the raw material for leucocyte-reduced pooled platelet concentrates.