Objective To compare the recovery rate of frozen platelets prepared by pooled buffy coats(PBCs)under different standing time points,so as to improve the preparation method of platelets.Methods The whole blood(400 ml)were collected from 50 blood donators,and was equally divided into 1-hour group(standing time of buffy coat pooled platelet for 1 h,n=50)and 24-hour group(standing time of buffy coat pooled platelet for 24 h,n=50).The concentrated platelets were stored at-80℃.The recovery rate and morphology of the platelet were compared between the two groups one month later.Results The platelet count and recovery rate of the frozen platelet in the 24-hour group were higher than those in the 1-hour group([2.45±0.13]×109 vs.[2.32±0.10]×109,83.55%±5.42%vs.79.32%±5.75%,both P<0.05).There was no significant difference in the average platelet volume,platelet distribution width,pH,P-selectin,or residual red blood cells between the two groups.Conclusion Residual red blood cells and platelet count from PBCs under different standing time points meet the national quality standards.The buffy coat pooled platelet count and recovery rate of 24-hour standing are higher than those of 1-hour standing.

Objective To investigate the risk factors of platelet transfusion refractoriness(PTR)in patients undergoing hematopoietic stem cell transplantation(HSCT)and its influence on the prognosis of the patients.Methods A total of 104 patients who underwent HSCT in The First Affiliated Hospital of Naval Medical University from February 2018 to February 2021 were enrolled and assigned to PTR group(n=36)or non-PTR group(n=68).The clinical data of the two groups were collected to investigate PTR-related factors in HSCT patients.The patients were followed up for 3 years after transplantation,and the survival and the influence of PTR on the prognosis were analyzed.Results The proportions of no platelet antibody matching,blood transfusion≥6 times,high fever,splenomegaly,infection,and skin and mucous membrane bleeding in the PTR group were significantly higher than those in the non-PTR group(P<0.05).The platelet count on admission in the PTR group was significantly lower than that in the non-PTR group(P<0.05).No platelet antibody matching(β=-0.837),blood transfusion≥6 times(β=0.905),high fever(β=0.516),splenomegaly(β=0.773),and infection(β=0.695)were independent risk factors of PTR in HSCT patients(P<0.05).The rates of overall survival(OS)and recurrence-free survival(RFS)in the PTR group were significantly lower than those in the non-PTR group(P<0.05).After multivariate adjustment,PTR was associated with poorer OS(HR=2.764,95%CI:1.267-6.643)and RFS(HR=2.139,95%CI:1.046-5.114).Conclusion The occurrence of PTR in HSCT patients is related to platelet antibody matching,blood transfusion frequency,high fever,splenomegaly,and infection.PTR can affect the prognosis of HSCT patients,and shorten the OS and RFS.

Metabolic engineering has been widely used for production of natural medicinal molecules. However, engineering high-yield platforms is hindered in large part by limited knowledge of complex regulatory machinery of metabolic network. N⁶-Methyladenosine (m⁶A) modification of RNA plays critical roles in regulation of gene expression. Herein, we identify 1470 putatively m⁶A peaks within 1151 genes from the haploid Saccharomyces cerevisiae strain. Among them, the transcript levels of 94 genes falling into the pathways which are frequently optimized for chemical production, are remarkably altered upon overexpression of IME4 (the yeast m⁶A methyltransferase). In particular, IME4 overexpression elevates the mRNA levels of the methylated genes in the glycolysis, acetyl-CoA synthesis and shikimate/aromatic amino acid synthesis modules. Furthermore, ACS1 and ADH2, two key genes responsible for acetyl-CoA synthesis, are induced by IME4 overexpression in a transcription factor-mediated manner. Finally, we show IME4 overexpression can significantly increase the titers of isoprenoids and aromatic compounds. Manipulation of m⁶A therefore adds a new layer of metabolic regulatory machinery and may be broadly used in bioproduction of various medicinal molecules of terpenoid and phenol classes.