RÉSUMÉ
This study explores the effects of enhancing the definitive hematopoiesis(DH)signals during the differentiation of human embryonic stem cells(hESCs)into hematopoietic stem/progenitor cells on the generation efficiency and effector function of natural killer(NK)cells generated from hESCs(also known as hESC-NK cells).The hESC(H1)were transformed into embryoid bodies(Ebs)by centrifugation,and during the induction of K562,were used to analyze the efficiency of hematopoietic differentiation,the efficiency of NK cell generation from hESC,the in vitro effector functions,and the expression of effector function related surface receptors.Compared to the control group,the DH group had a significant increase in the number of arterial hematopoietic endothelial cells(CD34+DLL4+)and a significant decrease in primitive hematopoietic related cells(CD34-CD43+)on day 8 of hematopoietic differentiation(P<0.05).On day 28 of NK cell differentiation,the DH group demonstrated a significant increase in the number of NK cells(CD45+CD56+),while a slight increase in the expression of effector function-related molecules such as IFN-γ,Granzyme B,Perforin and CD107a without statistical significance.Furthermore,the activation receptors CD16a and CD69 were significantly increased,NKP46 was significantly decreased,the inhibitory receptor NKG2A was significantly increased,while CD96 was significantly decreased on hESC-NK cells of DH groups(P<0.05).Conclusively,enhancing the signals for definitive hematopoiesis during hESC differentiation into hematopoietic stem/progenitor cells significantly improves the yield of NK cells and the expression of CD16a without affecting their in vitro effector functions.Our study provides a new approach to improving the efficiency of hESC-NK cell or iPSC-NK cell generation.
RÉSUMÉ
Objective To compare the value of pacemaker implantation using the subclavian vein (SCV) puncture and thecephalic vein(CV) cutdown approach.Methods One hundred and forty-six patients were randomized into SCV group (98 patients) and CV group (48 patients).We observed the success rate,surgery duration,fluoroscopy time and complications of the two groups.Results The SCV group had significantly higher success rate,shorter duration of surgery and fluoroscopy than the CV group (success rate:100％ (98/98) vs.89％ (43/48),x2 =10.5,P ＜ 0.05 ; duration of surgery:(118 ± 35) min vs.(256 ± 75)min,t =12.12,P ＜0.01 ; duration of fluoroscopy:(15 ±5) min vs.(35 ± 10) min,t =13.08,P ＜0.01).Both groups had one case who developed compilations which were pocket hematoma and wire electrode dislocation respectively.The rate of complications was not significantly different between the two groups (P ＞ 0.05).Conclusion The SCV approach should be considered a preferable access in pacemaker implantation.