BACKGROUND:The number of hematopoietic stem cel s in the peripheral blood is very low at normal physiological state. So it is critical to mobilize hematopoietic stem cel s from donor’s bone marrow into the peripheral blood.
OBJECTIVE:To study the combination effect of AMD3100 and dexamethasone on the mobilization of hematopoietic stem cel s in mice, thereby laying the foundation for clinical application.
METHODS:C57BL/6 mice were injected with AMD3100 and dexamethasone alone or in combination. Then, hematopoietic stem cel s in the peripheral blood and bone marrow were col ected. CD34+cel concentration in the peripheral blood and bone marrow was determined by flow cytometer and the content of leucocytes in the peripheral blood was counted by a normal method. The CFU-Mix colony formation ability of hematopoietic stem cel s was identified by cel colony forming assay.
RESULTS AND CONCLUSION:The concentration of CD34+cel s in the peripheral blood and bone marrow, the content of leukocytes in the peripheral blood and the CFU-Mix colony formation ability of hematopoietic stem cel s were al improved by both AMD3100 and dexamethasone and especial y their combined use. This indicates that both AMD3100 and dexamethasone could mobilize hematopoietic stem cel s to migrate from the bone marrow to the peripheral blood, and when used in combination, the mobilization effect is better than that of single drug.

Objective To construct the prokaryotic expression plasmid of HHV-8 fusion antigen for diagnosis of HHV-8 infec-tion .Methods The combined fragment ORF59 ,ORF65 and K8 .1 by fusion PCR was integrated into pQE-80L and transfected into E .coli DH5α.Fusion protein was induced to express by IPTG .SDS-PAGE and Western blot were employed to detect the fusion protein .Fusion protein was used to detect serum of blood donors .Results The combined plasmid pQE-80L-ORF59-ORF65-K8 .1 was constructed successfully after verifying by restriction enzyme digestion and sequencing .The fusion protein was about 24 KD and could be specific combined with HHV-8 positive serum .The fusion protein had the same result to detect HHV-8 with the HHV-8 ELISA kit .Conclusion Fusion protein we construct can be used as diagnosis antigen to detect HHV-8 of blood donors and common people .

【Objective】 To explore the clinical value of thromboelas-tography, coagulation four items and platelet count in guiding platelet transfusion in critically ill patients. 【Methods】 A total of 188 critically ill patients in Intensive Care Unit of our hospital from January 2020 to January 2022 were selected as subjects, and were divided into study group(n=89) and the control(n=99) according to the presence of bleeding symptoms. T-test was used for comparative analysis between the two groups. Spearman was used to analyze the correlation between TEG, coagulation four items and platelet count, and binary Logistic regression analysis was used to predict the influential factors of bleeding in critically ill patients, ROC curve was used to analyze the guiding value of the above-mentioned indexes for platelet transfusion. 【Results】 1) K and PT values in the study group, above the normal range, were significantly higher than those in the control, while the Angle value, MA value, CI value, FIB value and platelet count were significantly lower than those of the control, among which MA value, CI value and platelet count were below the normal range. 2) TEG, coagulation four items and platelet count were correlated. MA and CI values were positively correlated with platelet count, instead, R and K values were negatively correlated. R value was positively correlated with PT and APTT, CI value, on the contrary, was negatively correlated, K value was positively correlated with PT, while Angle value and MA value were negatively correlated. 3) Binary Logistic regression analysis showed that decreased MA value and decreased platelet count were independent risk factors for predicting bleeding in critically ill patients(P<0.05). 4) ROC curve analysis showed that the areas under ROC curve corresponding to Angle value, MA value, CI value, FIB value and platelet count were 0.866, 0.932, 0.9, 0.838 and 0.987(P<0.05). The sensitivity was highest in platelet count and lowest in FIB. The specificity was highest in MA and lowest in Angle. Compared with the single index, the area under the curve of the combined index(K value, MA value, CI value, PT value and platelet count) was 0.995(P<0.05), Yoden index 0.944, sensitivity 100%, specificity 93.3%, all higher than the individual index. 【Conclusion】 Thromboelas-tography combined with coagulation four items and platelet count can be used to accurately predict the critically ill patients with bleeding risk. To guide clinical platelets transfusion, the combined use of indexes, including K value, MA, CI value, PT and platelet count, is superior to separate use of them as the former showed better sensitivity and specificity, demonstrating a good clinical value.