Platelet-rich fibrin(PRF)is widely used in dentistry and other fields of medicine,and its use has become popular in dental implantology.In several published studies,PRF has been used as a barrier membrane.A barrier me...Platelet-rich fibrin(PRF)is widely used in dentistry and other fields of medicine,and its use has become popular in dental implantology.In several published studies,PRF has been used as a barrier membrane.A barrier membrane is a sheet of a certain material that acts as a biological and mechanical barrier against the invasion of cells that are not involved in bone formation,such as epithelial cells.Among the basic requirements of a'barrier membrane,occlusivity,stiffness,and space maintenance are the criteria that PRF primarily lacks;therefore,it does not fall under the category of barrier membranes.However,there is evidence that PRF membranes are useful in significantly improving wound healing.Does the PRF membrane act as a barrier?Should we think of adding or subtracting some points from the ideal requirements of a barrier membrane,or should we coin a new term or concept for PRF that will incorporate some features of a barrier membrane and be a combination of tissue engineering and biotechnology?This review is aimed at answering the basic question of whether the PRF membrane should be considered a barrier membrane or whether it is something more beyond the boundaries of a barrier membrane.展开更多
Objective: To observe the effect of Xiaoyu Zhixue tablet (消瘀止血片,XYZXT) on the expression of platelet membrane glycoproteins in patients with hemorrhagic thrombopathy, and to explore its possible mechanism. Method...Objective: To observe the effect of Xiaoyu Zhixue tablet (消瘀止血片,XYZXT) on the expression of platelet membrane glycoproteins in patients with hemorrhagic thrombopathy, and to explore its possible mechanism. Methods: The total of 148 patients with hemorrhagic thrombopathy were randomly divided into two groups, the traditional Chinese medicicne (TCM) group (n=98) treated with XYZXT and the Western medicine (WM) group (n=50) treated with adrenosin, vitamins C, K and P, both for 6 months. The therapeutic effect and the recovery rate of platelet aggregation in the two groups were observed. And platelet membrane glycoprotein (GP) Ⅰb/Ⅸ, GPⅡb/Ⅲa complexes, GPⅠb, GPⅡb, GP Ⅲa and P-selectin were analyzed by flow cytometry in both groups before and after treatment and also in 34 normal healthy subjects. Results: The total effective rate of hemostasis was 89. 8% in TCM group and 54. 0% in the WM group (x2=45.83, P<0.01), and the recovery rate of platelet aggregation was 72.4% and 4.0% respectively (x2=62.06, P<0.01). The fluorescence intensity of GP Ⅰ b/Ⅸ, GPⅡb/Ⅲa complexes, GPⅠb, GPⅢa and P-selectin were lower in both groups before treatment than those in the healthy subjects. Expression of above-mentioned marks was elevated in TCM group after 6 months' therapy, which was insignificantly different as compared with the healthy subjects (P>0.05) and higher than those in the WM group (P<0.05). Conclusion: One of the mechanisms in treating hemorrhagic thrombopathy with XYZXT is that it could regulate the expression of GP Ⅰb/Ⅸ, GPⅡ b/Ⅲa complexes, GPⅠb, GPⅢa and P-selectin at the level of receptor protein.展开更多
To investigate the role of platelet membrane glycoprotein （GP） Ib/Ⅸ/Ⅴ complex and its subunit GP Ibα in patients with hemorrhagic thrombopathy （HT）, the expressions of GP Ib/Ⅸ/Ⅴ complex and GP Ibα,defined as...To investigate the role of platelet membrane glycoprotein （GP） Ib/Ⅸ/Ⅴ complex and its subunit GP Ibα in patients with hemorrhagic thrombopathy （HT）, the expressions of GP Ib/Ⅸ/Ⅴ complex and GP Ibα,defined as mean fluorescence intensity （MFI）, were assessed by flow cytometry. The maximum aggregation of platelet was determined by turbidity method. These indicators were compared among 68 HT patients with the presenting complaint of hemorrhage, 33 well-controlled HT patients and 32 normal healthy subjects. The results showed that the MFI of GP Ib/Ⅸ /Ⅴ complex and GP Ibα was markedly lower in HT patients with current hemorrhage than that in the healthy subjects, with difference being statistically significant （P〈0.05）. There was no significant difference in the expressions of GP Ib/ Ⅸ/ Ⅴ complex and GP Ibα between well-controlled HT patients and normal healthy subjects （P〉0.05）. It was concluded that the expression of GP Ib/Ⅸ /Ⅴ complex, the receptor of thrombin and von Willebrand factor, was down-regulated in HT patients with current hemorrhage, which might result in the dysfunction of platelet aggregation and recurrence of HT.展开更多
To explore the correlation between the C807T polymorphism of platelet membrane glycoprotein Ⅰa （GP Ⅰa） gene and aspirin resistance in Chinese people, 200 patients with high-risk of atherosclerosis took aspirin （1...To explore the correlation between the C807T polymorphism of platelet membrane glycoprotein Ⅰa （GP Ⅰa） gene and aspirin resistance in Chinese people, 200 patients with high-risk of atherosclerosis took aspirin （100 mg/d） for 7 days. Platelet aggregation function was detected using adenosine diphosphate （ADP） and arachidonic acid （AA） before and after the administration of aspirin. Then the subjects were divided into three groups according to the results of platelet aggregation function： an aspirin resistant （AR） group, an aspirin semi-responder （ASR） group and an aspirin-sensitive （AS） group. Platelet GP Ⅰa gene 807CT polymorphism was examined by means of polymerase chain reaction-sequence specific primers （PCR-SSP）. The results showed that T allelic frequency in AR group and ASR group were higher that of AS group （P〈0.005）, and the prevalence of genotypes （TT＋TC） of these two groups was significantly higher than that in AS group （P〈0.05）. Platelet GP Ⅰa T allele was significantly associated with aspirin resistance as revealed by multiple logistic regression （OR=3.76, 95% CI： 2.87-9.58）. The results suggest that inherited platelet GP Ⅰa variations may have an important impact on aspirin resistance and the presence of GP Ⅰa T allele may be a marker of genetic susceptibility to aspirin resistance.展开更多
The redistribution of platelet membrane glycoprotein IV (GPIV) and the release of intracellular Q-granule thrombospondin (TSP) were examined and the inhibition of 5-thromboglobulin (&TG) and platelet factor 4 (PF4...The redistribution of platelet membrane glycoprotein IV (GPIV) and the release of intracellular Q-granule thrombospondin (TSP) were examined and the inhibition of 5-thromboglobulin (&TG) and platelet factor 4 (PF4) in patients with chronic myelogenous leukemia (CML) was observed and quantitation of β-TG and PF4 in sera was conducted. GPIV in inactive platelet from CML was 36080±17010 molecules/platelet as compared with 13190±4810 from the controls (P<0,01), No abnormality was found in the distribution of platelet membrane GPIb and GPIIb/III.(P>0. 05). The GPIV redistribution on active platelet membrane induced thrombin (1U/ml) from CML and healthy donors was 44320132310 and 228001 12700 molecules/platelet respectively (P<0. 01 ). The difference in the release of intracellular Q-granule TSP between CML and the control group was not found (P>0.05). There was no direct correlation between GPIV expression and TSP binding after platelet activation. The high leveIs of β-TG and PF4 in sera inhibited release of intracellular a-granule TSP in vitro. These results indicate that the abnormality of platelet membrane GPIV is a common marker in CML, therefore the specific increase of platelet GPIV in patients with CML may be a useful tool for the diagnosis and monitoring of the platelet dysfunction. The release of interna1 TSP pools is hindered by either β-TG or PF4 in sera.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
Preparation and blood compatibility of different shape polyvinyl alcohol（PVA） membrane were investigated. Firstly, the tabular and tubular[polytetrafluoroethylene（PTFE） capillary as supporter] PVA membranes were p...Preparation and blood compatibility of different shape polyvinyl alcohol（PVA） membrane were investigated. Firstly, the tabular and tubular[polytetrafluoroethylene（PTFE） capillary as supporter] PVA membranes were prepared; then, methoxy polyethylene glycol（mPEG） was grafted onto the surface of the PVA membranes. The effects of the shape, structure and properties of the membrane surface on blood compatibility were studied in detail. The experiment results show that mPEG modified PVA membranes, especially mPEG modified tubular membrane, could availably repel the adhesion of the platelets. In addition, the anticoagulant mechanism of mPEG with a steric repulsion effectiveness was confirmed further via different grafting methods.展开更多
Objective: To investigate the effects of Xuezhikang capsule (XZK,血脂康胶囊) on blood lipids level, platelet activation and coagulation-fibrinolysis activity in patients with hyerlipidemia. Methods: Seventy-six patien...Objective: To investigate the effects of Xuezhikang capsule (XZK,血脂康胶囊) on blood lipids level, platelet activation and coagulation-fibrinolysis activity in patients with hyerlipidemia. Methods: Seventy-six patients of hyperlipidemia were randomly divided into two groups, the XZK group (n=38) treated with XZK 600mg, taken two times per day and the Simvastatin (SIM) group (n = 38) treated with SIM 20mg per day, with the treatment lasting 8 weeks for both groups. Levels of fasting serum lipids, including total cholesterol (TC), triglyceride (TG), high and low density lipoprotein cholesterol (HDL-C and LDL-C), plasma GMP-140, fibrinogen (FIB), tissue plasminogen activator (t-PA), plasminogen activator inhibitor type-1 (PAI-) and prothrombin time (PT) were all measured before and 8 weeks after treatment. Data were compared before and after treatment and also compared with those measured in 20 healthy subjects of control. Results: Before treantment the levels of TC, TG and LDL-C were obviously higher and HDL-C level was significantly lower in hyperlipidemia patients than those in healthy subjects (P<0.05 or P<0.01). After 4-8 weeks of XZK treatment, the levels of TC, TG, LDL-C and FIB and activities of GMP-140 and PAI-1 were obviously lowered (P<0. 05 or P<0. 01). But in the SIM group there was no obvious change in FIB (P>0.05), instead it showed obvious increase of HDL-C and decrease of TC and LDL-C after treatment (P<0.05 or P<0.01). Conclusion: XZK could inhibit platelet activity and improve coagulation-fibrinolysis function, besides its lipids lowering effect.展开更多
文摘Platelet-rich fibrin(PRF)is widely used in dentistry and other fields of medicine,and its use has become popular in dental implantology.In several published studies,PRF has been used as a barrier membrane.A barrier membrane is a sheet of a certain material that acts as a biological and mechanical barrier against the invasion of cells that are not involved in bone formation,such as epithelial cells.Among the basic requirements of a'barrier membrane,occlusivity,stiffness,and space maintenance are the criteria that PRF primarily lacks;therefore,it does not fall under the category of barrier membranes.However,there is evidence that PRF membranes are useful in significantly improving wound healing.Does the PRF membrane act as a barrier?Should we think of adding or subtracting some points from the ideal requirements of a barrier membrane,or should we coin a new term or concept for PRF that will incorporate some features of a barrier membrane and be a combination of tissue engineering and biotechnology?This review is aimed at answering the basic question of whether the PRF membrane should be considered a barrier membrane or whether it is something more beyond the boundaries of a barrier membrane.
文摘Objective: To observe the effect of Xiaoyu Zhixue tablet (消瘀止血片,XYZXT) on the expression of platelet membrane glycoproteins in patients with hemorrhagic thrombopathy, and to explore its possible mechanism. Methods: The total of 148 patients with hemorrhagic thrombopathy were randomly divided into two groups, the traditional Chinese medicicne (TCM) group (n=98) treated with XYZXT and the Western medicine (WM) group (n=50) treated with adrenosin, vitamins C, K and P, both for 6 months. The therapeutic effect and the recovery rate of platelet aggregation in the two groups were observed. And platelet membrane glycoprotein (GP) Ⅰb/Ⅸ, GPⅡb/Ⅲa complexes, GPⅠb, GPⅡb, GP Ⅲa and P-selectin were analyzed by flow cytometry in both groups before and after treatment and also in 34 normal healthy subjects. Results: The total effective rate of hemostasis was 89. 8% in TCM group and 54. 0% in the WM group (x2=45.83, P<0.01), and the recovery rate of platelet aggregation was 72.4% and 4.0% respectively (x2=62.06, P<0.01). The fluorescence intensity of GP Ⅰ b/Ⅸ, GPⅡb/Ⅲa complexes, GPⅠb, GPⅢa and P-selectin were lower in both groups before treatment than those in the healthy subjects. Expression of above-mentioned marks was elevated in TCM group after 6 months' therapy, which was insignificantly different as compared with the healthy subjects (P>0.05) and higher than those in the WM group (P<0.05). Conclusion: One of the mechanisms in treating hemorrhagic thrombopathy with XYZXT is that it could regulate the expression of GP Ⅰb/Ⅸ, GPⅡ b/Ⅲa complexes, GPⅠb, GPⅢa and P-selectin at the level of receptor protein.
基金supported by a grant from the National Natural Science Foundation of China (No. 30572441).
文摘To investigate the role of platelet membrane glycoprotein （GP） Ib/Ⅸ/Ⅴ complex and its subunit GP Ibα in patients with hemorrhagic thrombopathy （HT）, the expressions of GP Ib/Ⅸ/Ⅴ complex and GP Ibα,defined as mean fluorescence intensity （MFI）, were assessed by flow cytometry. The maximum aggregation of platelet was determined by turbidity method. These indicators were compared among 68 HT patients with the presenting complaint of hemorrhage, 33 well-controlled HT patients and 32 normal healthy subjects. The results showed that the MFI of GP Ib/Ⅸ /Ⅴ complex and GP Ibα was markedly lower in HT patients with current hemorrhage than that in the healthy subjects, with difference being statistically significant （P〈0.05）. There was no significant difference in the expressions of GP Ib/ Ⅸ/ Ⅴ complex and GP Ibα between well-controlled HT patients and normal healthy subjects （P〉0.05）. It was concluded that the expression of GP Ib/Ⅸ /Ⅴ complex, the receptor of thrombin and von Willebrand factor, was down-regulated in HT patients with current hemorrhage, which might result in the dysfunction of platelet aggregation and recurrence of HT.
文摘To explore the correlation between the C807T polymorphism of platelet membrane glycoprotein Ⅰa （GP Ⅰa） gene and aspirin resistance in Chinese people, 200 patients with high-risk of atherosclerosis took aspirin （100 mg/d） for 7 days. Platelet aggregation function was detected using adenosine diphosphate （ADP） and arachidonic acid （AA） before and after the administration of aspirin. Then the subjects were divided into three groups according to the results of platelet aggregation function： an aspirin resistant （AR） group, an aspirin semi-responder （ASR） group and an aspirin-sensitive （AS） group. Platelet GP Ⅰa gene 807CT polymorphism was examined by means of polymerase chain reaction-sequence specific primers （PCR-SSP）. The results showed that T allelic frequency in AR group and ASR group were higher that of AS group （P〈0.005）, and the prevalence of genotypes （TT＋TC） of these two groups was significantly higher than that in AS group （P〈0.05）. Platelet GP Ⅰa T allele was significantly associated with aspirin resistance as revealed by multiple logistic regression （OR=3.76, 95% CI： 2.87-9.58）. The results suggest that inherited platelet GP Ⅰa variations may have an important impact on aspirin resistance and the presence of GP Ⅰa T allele may be a marker of genetic susceptibility to aspirin resistance.
文摘The redistribution of platelet membrane glycoprotein IV (GPIV) and the release of intracellular Q-granule thrombospondin (TSP) were examined and the inhibition of 5-thromboglobulin (&TG) and platelet factor 4 (PF4) in patients with chronic myelogenous leukemia (CML) was observed and quantitation of β-TG and PF4 in sera was conducted. GPIV in inactive platelet from CML was 36080±17010 molecules/platelet as compared with 13190±4810 from the controls (P<0,01), No abnormality was found in the distribution of platelet membrane GPIb and GPIIb/III.(P>0. 05). The GPIV redistribution on active platelet membrane induced thrombin (1U/ml) from CML and healthy donors was 44320132310 and 228001 12700 molecules/platelet respectively (P<0. 01 ). The difference in the release of intracellular Q-granule TSP between CML and the control group was not found (P>0.05). There was no direct correlation between GPIV expression and TSP binding after platelet activation. The high leveIs of β-TG and PF4 in sera inhibited release of intracellular a-granule TSP in vitro. These results indicate that the abnormality of platelet membrane GPIV is a common marker in CML, therefore the specific increase of platelet GPIV in patients with CML may be a useful tool for the diagnosis and monitoring of the platelet dysfunction. The release of interna1 TSP pools is hindered by either β-TG or PF4 in sera.
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.
基金Supported by the National Natural Science Foundation of China(No.29405038)
文摘Preparation and blood compatibility of different shape polyvinyl alcohol（PVA） membrane were investigated. Firstly, the tabular and tubular[polytetrafluoroethylene（PTFE） capillary as supporter] PVA membranes were prepared; then, methoxy polyethylene glycol（mPEG） was grafted onto the surface of the PVA membranes. The effects of the shape, structure and properties of the membrane surface on blood compatibility were studied in detail. The experiment results show that mPEG modified PVA membranes, especially mPEG modified tubular membrane, could availably repel the adhesion of the platelets. In addition, the anticoagulant mechanism of mPEG with a steric repulsion effectiveness was confirmed further via different grafting methods.
文摘Objective: To investigate the effects of Xuezhikang capsule (XZK,血脂康胶囊) on blood lipids level, platelet activation and coagulation-fibrinolysis activity in patients with hyerlipidemia. Methods: Seventy-six patients of hyperlipidemia were randomly divided into two groups, the XZK group (n=38) treated with XZK 600mg, taken two times per day and the Simvastatin (SIM) group (n = 38) treated with SIM 20mg per day, with the treatment lasting 8 weeks for both groups. Levels of fasting serum lipids, including total cholesterol (TC), triglyceride (TG), high and low density lipoprotein cholesterol (HDL-C and LDL-C), plasma GMP-140, fibrinogen (FIB), tissue plasminogen activator (t-PA), plasminogen activator inhibitor type-1 (PAI-) and prothrombin time (PT) were all measured before and 8 weeks after treatment. Data were compared before and after treatment and also compared with those measured in 20 healthy subjects of control. Results: Before treantment the levels of TC, TG and LDL-C were obviously higher and HDL-C level was significantly lower in hyperlipidemia patients than those in healthy subjects (P<0.05 or P<0.01). After 4-8 weeks of XZK treatment, the levels of TC, TG, LDL-C and FIB and activities of GMP-140 and PAI-1 were obviously lowered (P<0. 05 or P<0. 01). But in the SIM group there was no obvious change in FIB (P>0.05), instead it showed obvious increase of HDL-C and decrease of TC and LDL-C after treatment (P<0.05 or P<0.01). Conclusion: XZK could inhibit platelet activity and improve coagulation-fibrinolysis function, besides its lipids lowering effect.
