Long-term preservation of human platelets will greatly reduce the risk of their shortage. Lyophilization has been proved feasible for this purpose. For the recovery of lyophilized platelets,rehydration is an important...Long-term preservation of human platelets will greatly reduce the risk of their shortage. Lyophilization has been proved feasible for this purpose. For the recovery of lyophilized platelets,rehydration is an important process. In this paper,the rehydration proc-esses for 1 mL and 2 mL samples were studied. The effects of prehydration duration(15,30,60,90,120 and 150 min) in 37°C water vapor and the concentration of rehydration solution(25%,50%,75%,100% platelet-poor plasma) on the recovery rate,MPV(mean platelet volume) and PDW(platelet distribution width) were investigated. The mass changes during the prehydration process were weighed. The optimized rehydration conditions are as follows:(1) for 1 mL sample,the prehydration duration was 15 min and for 2 mL sample the prehydration duration was 90 min;(2) the rehydration solution was 75% platelet-poor plasma. Under optimized conditions,the morphology of the rehydrated platelets kept normal and their ultrastructures kept intact,their aggregation capacity to thrombin(1 U/mL) was 82.8% of the fresh ones. These results will be helpful for designing the freeze-drying protocols for human platelets.展开更多
Typical antipsychotics, potent D2 dopamine receptor antagonists, are the most commonly used drugs in the treatment of bipolar disorders. In the central nervous system, the discovery of antagonistic interactions betwee...Typical antipsychotics, potent D2 dopamine receptor antagonists, are the most commonly used drugs in the treatment of bipolar disorders. In the central nervous system, the discovery of antagonistic interactions between A2A adenosine receptors and D2 dopamine receptors suggests that the adenosine system may be involved in the pathogenesis of different psychiatric disorders and in the therapeutic effectiveness of antipsychotic drugs. Previously, we have demonstrated an increase in A2A receptor expression and agonist affinity in platelets from psychotic patients treated with haloperidol. This result suggests that there is also a structural and functional interaction between A2A and D2 receptors in peripheral cells. In this work, we investigated the effect of different doses of typical drugs on A2A adenosine receptor binding and correlated these parameters with the severity of symptoms. We demonstrated, for the first time, that there was a strong correlation between A2A receptor affinity constant values (Kd) and drug doses in psychotic patients with a moderate severity of illness and moderate psychotic symptoms. The correlation was completely lost in patients with severe illness and severe psychotic symptoms. These results demonstrated that in platelets of patients affected by psychosis, typical antipsychotics modulated A2A receptor binding parameters;this regulation is dependent on the degree of D2 receptor occupancy in relation to the severity of psychotic symptoms, suggesting A2A receptors are a peripheral marker for individual therapy effectiveness.展开更多
Freeze-drying is a promising method for a long-term storage of human platelets.The moisture sorption characteristics of freeze-dried human platelets(FDHPs) were studied in this paper.The moisture sorption isotherms of...Freeze-drying is a promising method for a long-term storage of human platelets.The moisture sorption characteristics of freeze-dried human platelets(FDHPs) were studied in this paper.The moisture sorption isotherms of FDHPs and freeze-dried lyophilization buffer(FDLB) were measured at 4,25,and 37°C.The experimental data were fitted to Brunauer-Emmett-Teller(BET) and Guggenheim-Anderson-de Boer(GAB) equations.There were no sig-nificant statistical differences(P>0.05) between the sorption characteristics of FDHPs and FDLB at 4 and 25°C,while FDHPs absorbed more water at 37°C.The net isosteric heat of sorption was derived.The heat for FDHPs showed an abnormal negative value at low moisture contents when 25 and 37°C data were used.Dynamic sorption experiments were carried out at 25°C with environmental water activity controlled at 0.75,0.85,and 0.90.The moisture diffusion coefficient was fitted to be 8.24×10 -12 m 2 /s when experimental data at initial time were used.These results would be helpful in choosing prehydration and storage condition for FDHPs.展开更多
Platelets have essential roles in both health and disease. Normal platelet function is required for hemostasis.Inhibition of platelet function in disease or by pharmacological treatment results in bleeding disorders.O...Platelets have essential roles in both health and disease. Normal platelet function is required for hemostasis.Inhibition of platelet function in disease or by pharmacological treatment results in bleeding disorders.On the other hand,hyperactive platelets lead to heart attack and stroke.Calcium is a major second messenger in platelet activation,and elevated intracellular calcium leads to hyperactive platelets.Elevated platelet calcium has been documented in hypertension and diabetes;both conditions increase the likelihood of heart attack and stroke. Thus,proper regulation of calcium metabolism in the platelet is extremely important.Plasma membrane Ca2+-ATPase(PMCA)is a major player in platelet calcium metabolism since it provides the only significant route for calcium efflux.In keeping with the important role of calcium in platelet function,PMCA is a highly regulated transporter.In human platelets,PMCA is activated by Ca2+/calmodulin,by cAMP-dependent phosphorylation and by calpain-dependent removal of the inhibitory peptide.It is inhibited by tyrosine phosphorylation and calpain-dependent proteolysis.In addition,the cellular location of PMCA is regulated by a PDZ-domain-dependent interaction with the cytoskeleton during platelet activation.Rapid regulation by phosphorylation results in changes in the rate of platelet activation,whereas calpain-dependent proteolysis and interaction with the cytoskeleton appears to regulate later events such as clot retraction.In hypertension and diabetes,PMCA expression is upregulated while activity is decreased, presumably due to tyrosine phosphorylation.Clearly,a more complete understanding of PMCA function in human platelets could result in the identification of new ways to control platelet function in disease states.展开更多
目的建立一种基于DNA扩增和测序分型（PCR sequencing—based typing，PCR—SBT）的人类血小板抗原HPA-1～HPA-16w的基因分型方法。方法从免疫多态性数据库中下载HPA-1-HPA-16w的全套HPA核酸序列，以Primer Premier 5．0软件设计引物，...目的建立一种基于DNA扩增和测序分型（PCR sequencing—based typing，PCR—SBT）的人类血小板抗原HPA-1～HPA-16w的基因分型方法。方法从免疫多态性数据库中下载HPA-1-HPA-16w的全套HPA核酸序列，以Primer Premier 5．0软件设计引物，特异性扩增包含HPA—1a／1b到HPA-16aw／16bw多态性的核酸片段。通过调整引物序列和PCR条件获得单一的特异性扩增产物，PCR产物纯化后直接进行DNA序列分析并确定HPA基因型。通过对2份标准样本的HPA分型验证PCR-SBT方法的准确性；并利用PCR-SBT法对2008年度国际输血协会（ISBT）第14届国际血小板免疫学工作组提供的16份比对样本（包括6个含有基因突变的干扰样本）进行HPA基因分型。结果设计11对引物扩增和测序16个HPA系统。2份标准样本的HPA基因型分别为HPA：1aa／2aa／3ab／4aa／5ab／6aa．／7aa．／8aa／9aa／10aa／11aa／12aa／13aa／14aa／15aa／16aa和HPA：1aa／2aa／3aa／4aa／5aa／6aa／7aa／8aa／9aa／10aa／11aa／12aa／13aa／14aa／15aa／16aa。16份ISBT考核样本的256个HPA基因型结果清晰，其中HPA-1～HPA-6w、HPA-9w和HPA-15共8个系统的128个基因型结果与ISBT参考结果完全一致。结论建立了HPA-1～HPA-16w的PCR—SBT分型方法，结合高通量的DNA序列分析仪，具有简单、快速和准确的优点，适合于临床HPA全套基因分型，具有良好的应用前景。展开更多
基金supported by the National Natural Science Foundation of China (50606032)Specialized Research Fund for the Doctoral Program of Higher Education (20070335145)Scientific Research Foundation for Advanced Talents,Nanjing University of Aeronautics and Astronautics,China (1001-909382)
文摘Long-term preservation of human platelets will greatly reduce the risk of their shortage. Lyophilization has been proved feasible for this purpose. For the recovery of lyophilized platelets,rehydration is an important process. In this paper,the rehydration proc-esses for 1 mL and 2 mL samples were studied. The effects of prehydration duration(15,30,60,90,120 and 150 min) in 37°C water vapor and the concentration of rehydration solution(25%,50%,75%,100% platelet-poor plasma) on the recovery rate,MPV(mean platelet volume) and PDW(platelet distribution width) were investigated. The mass changes during the prehydration process were weighed. The optimized rehydration conditions are as follows:(1) for 1 mL sample,the prehydration duration was 15 min and for 2 mL sample the prehydration duration was 90 min;(2) the rehydration solution was 75% platelet-poor plasma. Under optimized conditions,the morphology of the rehydrated platelets kept normal and their ultrastructures kept intact,their aggregation capacity to thrombin(1 U/mL) was 82.8% of the fresh ones. These results will be helpful for designing the freeze-drying protocols for human platelets.
文摘Typical antipsychotics, potent D2 dopamine receptor antagonists, are the most commonly used drugs in the treatment of bipolar disorders. In the central nervous system, the discovery of antagonistic interactions between A2A adenosine receptors and D2 dopamine receptors suggests that the adenosine system may be involved in the pathogenesis of different psychiatric disorders and in the therapeutic effectiveness of antipsychotic drugs. Previously, we have demonstrated an increase in A2A receptor expression and agonist affinity in platelets from psychotic patients treated with haloperidol. This result suggests that there is also a structural and functional interaction between A2A and D2 receptors in peripheral cells. In this work, we investigated the effect of different doses of typical drugs on A2A adenosine receptor binding and correlated these parameters with the severity of symptoms. We demonstrated, for the first time, that there was a strong correlation between A2A receptor affinity constant values (Kd) and drug doses in psychotic patients with a moderate severity of illness and moderate psychotic symptoms. The correlation was completely lost in patients with severe illness and severe psychotic symptoms. These results demonstrated that in platelets of patients affected by psychosis, typical antipsychotics modulated A2A receptor binding parameters;this regulation is dependent on the degree of D2 receptor occupancy in relation to the severity of psychotic symptoms, suggesting A2A receptors are a peripheral marker for individual therapy effectiveness.
基金Project supported by the Natural Science Foundation of Zhejiang Province,China(No.Y1090409)the Doctoral Fund of Ministry of Education of China(No.20070335145)
文摘Freeze-drying is a promising method for a long-term storage of human platelets.The moisture sorption characteristics of freeze-dried human platelets(FDHPs) were studied in this paper.The moisture sorption isotherms of FDHPs and freeze-dried lyophilization buffer(FDLB) were measured at 4,25,and 37°C.The experimental data were fitted to Brunauer-Emmett-Teller(BET) and Guggenheim-Anderson-de Boer(GAB) equations.There were no sig-nificant statistical differences(P>0.05) between the sorption characteristics of FDHPs and FDLB at 4 and 25°C,while FDHPs absorbed more water at 37°C.The net isosteric heat of sorption was derived.The heat for FDHPs showed an abnormal negative value at low moisture contents when 25 and 37°C data were used.Dynamic sorption experiments were carried out at 25°C with environmental water activity controlled at 0.75,0.85,and 0.90.The moisture diffusion coefficient was fitted to be 8.24×10 -12 m 2 /s when experimental data at initial time were used.These results would be helpful in choosing prehydration and storage condition for FDHPs.
文摘Platelets have essential roles in both health and disease. Normal platelet function is required for hemostasis.Inhibition of platelet function in disease or by pharmacological treatment results in bleeding disorders.On the other hand,hyperactive platelets lead to heart attack and stroke.Calcium is a major second messenger in platelet activation,and elevated intracellular calcium leads to hyperactive platelets.Elevated platelet calcium has been documented in hypertension and diabetes;both conditions increase the likelihood of heart attack and stroke. Thus,proper regulation of calcium metabolism in the platelet is extremely important.Plasma membrane Ca2+-ATPase(PMCA)is a major player in platelet calcium metabolism since it provides the only significant route for calcium efflux.In keeping with the important role of calcium in platelet function,PMCA is a highly regulated transporter.In human platelets,PMCA is activated by Ca2+/calmodulin,by cAMP-dependent phosphorylation and by calpain-dependent removal of the inhibitory peptide.It is inhibited by tyrosine phosphorylation and calpain-dependent proteolysis.In addition,the cellular location of PMCA is regulated by a PDZ-domain-dependent interaction with the cytoskeleton during platelet activation.Rapid regulation by phosphorylation results in changes in the rate of platelet activation,whereas calpain-dependent proteolysis and interaction with the cytoskeleton appears to regulate later events such as clot retraction.In hypertension and diabetes,PMCA expression is upregulated while activity is decreased, presumably due to tyrosine phosphorylation.Clearly,a more complete understanding of PMCA function in human platelets could result in the identification of new ways to control platelet function in disease states.
文摘目的建立一种基于DNA扩增和测序分型（PCR sequencing—based typing，PCR—SBT）的人类血小板抗原HPA-1～HPA-16w的基因分型方法。方法从免疫多态性数据库中下载HPA-1-HPA-16w的全套HPA核酸序列，以Primer Premier 5．0软件设计引物，特异性扩增包含HPA—1a／1b到HPA-16aw／16bw多态性的核酸片段。通过调整引物序列和PCR条件获得单一的特异性扩增产物，PCR产物纯化后直接进行DNA序列分析并确定HPA基因型。通过对2份标准样本的HPA分型验证PCR-SBT方法的准确性；并利用PCR-SBT法对2008年度国际输血协会（ISBT）第14届国际血小板免疫学工作组提供的16份比对样本（包括6个含有基因突变的干扰样本）进行HPA基因分型。结果设计11对引物扩增和测序16个HPA系统。2份标准样本的HPA基因型分别为HPA：1aa／2aa／3ab／4aa／5ab／6aa．／7aa．／8aa／9aa／10aa／11aa／12aa／13aa／14aa／15aa／16aa和HPA：1aa／2aa／3aa／4aa／5aa／6aa／7aa／8aa／9aa／10aa／11aa／12aa／13aa／14aa／15aa／16aa。16份ISBT考核样本的256个HPA基因型结果清晰，其中HPA-1～HPA-6w、HPA-9w和HPA-15共8个系统的128个基因型结果与ISBT参考结果完全一致。结论建立了HPA-1～HPA-16w的PCR—SBT分型方法，结合高通量的DNA序列分析仪，具有简单、快速和准确的优点，适合于临床HPA全套基因分型，具有良好的应用前景。
