OBJECTIVE: To study the effect of gradient shear stress on platelet aggregation by microfluidic chip Technology. METHODS: Microfluidic chip was used to simulate 80% fixed stenotic microchannel, and the hydrodynamic behavior of the stenotic microchannel model was analyzed by the finite element analysis module of sollidwork software. Microfluidic chip was used to analyze the adhesion and aggregation behavior of platelets in patients with different diseases, and flow cytometry was used to detect expression of the platelet activation marker CD62p. Aspirin, Tirofiban and protocatechuic acid were used to treat the blood, and the adhesion and aggregation of platelets were observed by fluorescence microscope. RESULTS: The gradient fluid shear rate produced by the stenosis model of microfluidic chip could induce platelet aggregation, and the degree of platelet adhesion and aggregation increased with the increase of shear rate within a certain range of shear rate. The effect of platelet aggregation in patients with arterial thrombotic diseases were significantly higher than normal group (P<0.05), and the effect of platelet aggregation in patients with myelodysplastic disease was lower than normal group (P<0.05). CONCLUSION The microfluidic chip analysis technology can accurately analyze and evaluate the platelet adhesion and aggregation effects of various thrombotic diseases unde the environment of the shear rate, and is helpful for auxiliary diagnosis of clinical thrombotic diseases.
Humans ; Microfluidics ; Platelet Adhesiveness ; Platelet Aggregation ; Blood Platelets/metabolism* ; Platelet Aggregation Inhibitors/pharmacology* ; Platelet Activation/physiology* ; Thrombosis

OBJECTIVE: To explore the regulation of mitochondria on platelet apoptosis and activation, and the relationship between platelet apoptosis and activation. METHODS: Platelets were isolated from peripheral venous blood of healthy volunteers. Cyclosporin A (CsA), which has a protective effect on the function of platelet mitochondria, BAPTA, which can chelate calcium ions across membranes in platelets, and NAC, an antioxidant that reduces the level of intracellular reactive oxygen species, were selected for coincubation with washed platelets, respectively. By flow cytometry, platelet aggregator was used to detect the changes of platelet mitochondrial function and platelet activation indexes after different interventions. RESULTS: H89, staurosporine, and A23187 led to platelet mitochondrial abnormalities, while CsA could effectively reverse the decline of platelet mitochondrial membrane potential caused by them. Antioxidant NAC could reverse platelet mitochondrial damage correspondingly, and completely reverse platelet shrinkage and phosphatidylserine eversion induced by H89. BAPTA, prostaglandin E1, acetylsalicylic acid and other inhibitors could not reverse the decline of platelet mitochondrial membrane potential. CONCLUSION Mitochondrial function plays an important role in platelet apoptosis and activation. Abnormal mitochondrial function causes the imbalance of reduction/oxidation state in platelets, which leads to platelet apoptosis. Platelet apoptosis and activation are independent signal processes.
Humans ; Blood Platelets/metabolism* ; Antioxidants/pharmacology* ; Mitochondria/physiology* ; Platelet Activation ; Apoptosis ; Membrane Potential, Mitochondrial ; Reactive Oxygen Species/pharmacology*

OBJECTIVE: To explore the main factors of platelet spreading and provide the foundation for related research. METHODS: Platelets (2×10⁷/ml) were draw from C57BL/6J mouse and kept at 22 ℃ for 1-2 hours. Platelets (2×10⁷/ml) were were allowed to adhere and spread on the fibrinogen-coated slides, after staining F-actin in platelets, the platelets were observed with the confocal microscopy. The effects of different concentrations of fibrinogen (10 μg/ml, 30 μg/ml, 100 μg/ml) and kinds of agonists ［thrombin(0.01,0.05,0.1 U/ml), ADP（5,10,20 μmol/L）, U46619（0.125,0.25,0.5 μmol/L）］ on platelets were analyzed. The platelet spreading was successful if the spreading rate was higher after treated with agonists. RESULTS: Compared to the group which coated with 10 μg/ml and 100 μg/ml fibrinogen, the platelet density is optimal when coated with 30 μg/ml fibrinogen. In addition, under the stimulation of thrombin, ADP and U46619, the spreading rate of platelets showed a certain concentration-dependent increasing. CONCLUSION The platelet spreading is easily influenced by various factors, the platelet spreading can be induced successfully at 0.1 U/ml thrombin, 20 μmol/L ADP and 0.5 μmol/L U46619 on the slide coated with 30 μg/ml fibrinogen.
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology* ; Adenosine Diphosphate ; Animals ; Blood Platelets/physiology* ; Fibrinogen ; Humans ; Mice ; Mice, Inbred C57BL ; Platelet Adhesiveness/physiology* ; Thrombin/pharmacology*

Wound biotherapy, represented by platelet concentrate derivatives, has attracted much attention. However, there are some different viewpoints due to the disunity of quality control of preparation, the ways of use, and so on. The members of the consensus writing group reviewed a large number of literatures, screened out high-quality evidence references, combined with the repeated discussion of experts in the field of wound repair to form a guiding consensus of experts, so as to guide medical personnel using enriched platelet treatment scientifically and standardly in wound repair.
Blood Platelets/physiology* ; Consensus ; Humans ; Wound Healing/physiology*

BACKGROUND: Hypertension and atherosclerosis are bidirectionally related, while platelet count could serve as an indicator of endothelial repair. Therefore, high platelet counts could be associated with hypertension by indicating more intense endothelial repair activity. Furthermore, short stature has been shown to constitute a risk of atherosclerosis. Since inflammation-related single-nucleotide polymorphism (SNP (rs3782886)) is reportedly associated with myocardial infarction and short stature, rs3782886 could be associated with a high platelet count and thus more intense endothelial repair activity. METHODS: We conducted a cross-sectional study of 988 elderly Japanese who participated in a general health check-up. Short stature was defined as a height of at or under the 25th percentile of the study population, and high platelet count as the highest tertiles of the platelet levels. RESULTS: High platelet counts were found to be independently and positively associated with hypertension while rs3782886 was independently associated with high platelet levels and short stature. The classical cardiovascular risk factor-adjusted odds ratio (OR) and 95% confidence interval (CI) of high platelet count for hypertension was 1.34 (1.02, 1.77). With non-minor homo of the rs3782886 as the reference group, the adjusted OR and 95% CI for high platelet count and short stature of minor home were 2.40 (1.30, 4.42) and 2.21 (1.16, 4.21), respectively. CONCLUSION SNP (rs3782886) was shown to be associated with high platelet count and short stature. This result partly explains how a genetic factor can influence the impact of height on endothelial repair.
Aged ; Aged, 80 and over ; Blood Platelets ; metabolism ; Body Height ; genetics ; Cross-Sectional Studies ; Endothelium, Vascular ; physiology ; Female ; Genetic Association Studies ; Genetic Predisposition to Disease ; Genotype ; Humans ; Hypertension ; blood ; epidemiology ; genetics ; Male ; Middle Aged ; Odds Ratio ; Platelet Count ; Polymorphism, Single Nucleotide

BackgroundThe relationship between obstructive sleep apnea (OSA) and platelet reactivity in patients undergoing percutaneous coronary intervention (PCI) has not been defined. The present prospective, single-center study explored the relationship between platelet reactivity and OSA in patients with PCI.

MethodsA total of 242 patients were finally included in the study. OSA was screened overnight by polysomnography. Platelet reactivity was assessed with a sequential platelet counting method, and the platelet maximum aggregation ratio (MAR) and average aggregation ratio were calculated. All patients were assigned per apnea-hypopnea index (AHI) to non-OSA (n = 128) and OSA (n = 114) groups. The receiver operating characteristic curve analysis was used to evaluate the accuracy of AHI for high platelet reactivity (HPR) on aspirin and clopidogrel, and multivariable logistic regression was used to determine the independent predictors of HPR on aspirin and clopidogrel.

ResultsMedian AHI was significantly higher in the OSA group than in the non-OSA group (34.5 events/h vs. 8.1 events/h, Z = -13.422, P < 0.001). Likewise, median arachidonic acid- and adenosine diphosphate-induced maximum aggregation rate (MAR) in the OSA group was significantly higher than those in the non-OSA group (21.1% vs. 17.7%, Z = -3.525, P < 0.001 and 45.8% vs. 32.2%, Z = -5.708, P < 0.001, respectively). Multivariable logistic regression showed that OSA was the only independent predictor for HPR on aspirin (odds ratio [OR]: 1.055, 95% confidence interval [CI]: 1.033-1.077, P < 0.001) and clopidogrel (OR: 1.036, 95% CI: 1.017-1.056, P < 0.001). The cutoff value of AHI for HPR on aspirin was 45.2 events/h (sensitivity 47.1% and specificity 91.3%), whereas cutoff value of AHI for HPR on clopidogrel was 21.3 events/h (sensitivity 68.3% and specificity 67.7%).

ConclusionPlatelet reactivity appeared to be higher in OSA patients with PCI despite having received a loading dose of aspirin and clopidogrel, and OSA might be an independent predictor of HPR on aspirin and clopidogrel.

Adult ; Aged ; Aged, 80 and over ; Blood Platelets ; physiology ; Female ; Humans ; Male ; Middle Aged ; Multivariate Analysis ; Percutaneous Coronary Intervention ; Prospective Studies ; Sleep Apnea, Obstructive ; physiopathology ; surgery

BackgroundThe Patterns of Non-Adherence to Anti-Platelet Regimens in Stented Patients (PARIS) bleeding score is a novel score for predicting the out-of-hospital bleeding risk after percutaneous coronary intervention (PCI). However, whether this score has the same value in non-European and American populations is unclear. This study aimed to assess the PARIS bleeding score's predictive value of bleeding in patients after PCI in the Chinese population.

MethodsWe performed a prospective, observational study of 10,724 patients who underwent PCI from January to December 2013, in Fuwai Hospital, China. We defined the primary end point as major bleeding (MB) according to Bleeding Academic Research Consortium definition criteria including Type 2, 3, or 5. The predictive value of the PARIS bleeding score was assessed with the area under the receiver operating characteristic (AUROC) curve.

ResultsOf 9782 patients, 245 (2.50%) MB events occurred during the 2 years of follow-up. The PARIS bleeding score was significantly higher in the MB group than that of non-MB group (4.00 [3.00, 5.00] vs. 3.00 [2.00, 5.00], Z = 3.71, P < 0.001). According to risk stratification of the PARIS bleeding score, the bleeding risk in the intermediate- and high-risk groups was 1.50 times (hazard ratio [HR]: 1.50; 95% confidence interval [CI]: 1.160-1.950; P = 0.002) and 2.27 times higher (HR: 2.27; 95% CI: 1.320-3.900; P = 0.003) than that in the low-risk group. The PARIS bleeding score showed a moderate predictive value for MB in the overall population (AUROC: 0.568, 95% CI: 0.532-0.605; P < 0.001) and acute coronary syndrome (ACS) subgroup (AUROC: 0.578, 95% CI: 0.530-0.626; P = 0.001) and tended to be predictive in the non-ACS subgroup (AUROC: 0.556, 95% CI: 0.501-0.611; P = 0.054).

ConclusionThe PARIS bleeding score shows good clinical value for risk stratification and has a significant, but relatively limited, prognostic value for out-of-hospital bleeding in the Chinese population after PCI.

Acute Coronary Syndrome ; pathology ; surgery ; Aged ; Blood Platelets ; physiology ; China ; Female ; Hemorrhage ; diagnosis ; prevention & control ; Humans ; Male ; Middle Aged ; Percutaneous Coronary Intervention ; methods ; Prognosis ; Prospective Studies

Gastric cancer (GC) is one of the most common tumor in the world, and remains a major public health problem and one of the leading causes of death. Recently many researches have demonstrated that systemic inflammatory response is associated with prognosis and response to therapy in gastric cancer, and the peripheral blood count test can partly reflect the systemic inflammatory response. Based on the peripheral blood count test, there are a lot of research regarding the relation between the platelet count (PLT), neutrophil, lymphocyte, white blood cell (WBC), neutrophil to lymphocyte ratio(NLR), platelet to lymphocyte ratio (PLR) with their prognostic role in gastric cancer. A high PLT and preoperative lymphocytopenia are both associated with increased lymph node metastasis, stage (III(+IIII(), serosal invasion (T3+T4) risk and poorer overall survival. Besides above, platelet monitoring following surgery can be applied to predict the recurrence for patients with GC that suffer preoperative high PLT but have restored PLT levels following resection. Moreover systemic inflammatory factors based on blood parameters, such as PLR, NLR and so on, have relation with the poor prognosis of patients with GC. Among them, high NLR is a negative predictor of prognosis in GC patients. However PLR remains inconsistent, while most researches demonstrated high PLR may be useful prognostic factor rather than independent prognostic factor. There are still some limitations which include various cut-off values, little of clinician attention, the uncertain mechanism, etc. Here we review the research progress in the prognostic role of the blood count test in gastric cancer.
Blood Cell Count ; methods ; statistics & numerical data ; Blood Platelets ; physiology ; Humans ; Inflammation ; blood ; diagnosis ; immunology ; Leukocyte Count ; statistics & numerical data ; Lymphatic Metastasis ; diagnosis ; immunology ; Lymphocyte Count ; statistics & numerical data ; Lymphopenia ; blood ; physiopathology ; Neoplasm Invasiveness ; immunology ; Neoplasm Recurrence, Local ; blood ; diagnosis ; Neoplasm Staging ; statistics & numerical data ; Neutrophils ; immunology ; Platelet Count ; statistics & numerical data ; Prognosis ; Stomach Neoplasms ; blood ; diagnosis ; immunology ; mortality ; Treatment Outcome

OBJECTIVETo investigate the value of evaluating 5 platelet parameters in predicting delayed graft function (DGF) in patients following kidney transplantation.

METHODSWe retrospectively analyzed the pre- and postoperative (within 2 months) data of 330 renal transplant recipients. The cases with DGF and those without were analyzed to assess the association between relationship between DGF following transplantation and the variations of blood platelet parameters including platelet count (PLT), large platelet ratio (P-LCR), mean platelet volume (MPV), platelet volume distribution width (PDW) and platelet hematocrit (PCT).

RESULTSThe DGF and non-DGF cases were comparable for the platelet parameters before the operation. On postoperative day 7 when the diagnosis of DGF was made, PLT (P<0.05) and PCT (P<0.02) were significantly lower while MPV (P<0.01), PDW (P=0.036) and P-LCR (P=0.01) significantly higher in DGF group than in non-DGF group. The AUCs of P-LCR (0.611±0.047), PDW (0.603±0.048) and MPV (0.762±0.037) were significantly higher than the reference area (P<0.05) with cut-off values of 34.80%, 12.95fl and 11.55fl, respectively. MPV showed a high sensitivity, specificity and Youden index for predicting DFG; PDW and P-LCR had a high sensitivity but a low specificity for predicting DFG with a modest diagnostic value. PLT and PCT, with AUCs of were 0.37 and 0.38, respectively, did not have a predictive value for DGF.

CONCLUSIONSSignificant variations in platelet parameters occur in the event of DGF in renal transplant recipients, and monitoring the postoperative changes in MPV, PDW, and P-LCR can help in early diagnosis and treatment of DGF. MPV has a moderate value (0.7-0.9) in predicting DGF, and a MPV>11.55 fl suggests the risk of DGF.

Area Under Curve ; Blood Platelets ; Delayed Graft Function ; Humans ; Kidney ; physiology ; Kidney Function Tests ; Kidney Transplantation ; Mean Platelet Volume ; Platelet Count ; Postoperative Period ; ROC Curve ; Retrospective Studies ; Sensitivity and Specificity

Vitamin D is an important steroid hormone, which has a wide biological effect and is the protective factor against cardiovascular disease and other diseases. At present, the etiology and pathogenesis of Kawasaki disease (KD) remain unknown, but recent studies have shown that vitamin D insufficiency or deficiency is associated with KD. Vitamin D insufficiency or deficiency may affect KD via its influence on inflammatory response, adipokine, endothelial function, platelet function, and DNA methylation and increase the risk of coronary artery lesions. This article reviews the research advances in the association between vitamin D and KD and possible mechanisms of action.
Adipokines ; physiology ; Animals ; Blood Platelets ; physiology ; DNA Methylation ; Epithelial Cells ; physiology ; Humans ; Mucocutaneous Lymph Node Syndrome ; etiology ; Vitamin D Deficiency ; complications