Platelet Aggregation Rate Research Articles

Low triiodothyronine syndrome is associated with platelet function in patients with nephrotic syndrome.

The objective of this study was to investigate the effects of low triiodothyronine syndrome (LT3S) on platelet function and clotting factors in patients with nephrotic syndrome(NS). Patients with primary nephrotic syndrome were divided into two groups, normal thyroid function (group A) and LT3S (group B), based on whether they had LT3S or not. Healthy subjects were selected as the control group (group C). Blood coagulation function was detected in each group. The platelet activation function (CD62P, CD63) was determined by flow cytometry. The platelet aggregation rate was detected by an optical method using adenosine diphosphate and arachidonic acid as inducers. The proportion of primary nephrotic syndrome with LT3S was 23.2% (69/298). Compared with group C, group A had higher CD62P and PAgTADP, and group B had higher CD62P, CD63, PAgTAA, and PAgTADP; the difference was statistically significant (all P < 0.05). There was no significant difference in renal pathology between group A and group B (X2 = 4.957, P = 0.421). Compared with group A, the 24-hour urine protein, CD63, PAgTAA, and PAgTADP were higher in group B, and APTT and Alb were lower. The difference was statistically significant (P < 0.05). Logistic regression analysis showed that LT3S was associated with CD36 (OR: 3.516; 95% CI: 1.742~8.186; P = 0.004) and PAgTAA (OR: 0.442; 95% CI: 1.001~1.251; P = 0.037). NS patients are prone to LT3S. Patients with LT3S may have abnormal platelet activation and increase of platelet aggregation.

Effect of vitamin D on antiplatelet drug responsiveness in elderly patients with ischemic stroke

Objective To investigate the effect of vitamin D on platelet reactivity after combined treatment with aspirin and clopidogrel in elderly patients with ischemic stroke. Methods A total of 190 elderly patients with ischemic stroke treated with aspirin and clopidogrel in Beijing Bo′ai Hospital from June 2017 to August 2018 were enrolled in this study.Venous blood was collected for platelet aggregation rate, 25-hydroxyvitamin D[25(OH)D] and clinical biochemical indexes during 1~2 weeks.According to 25 (OH) D quartile, the patients were further divided into Q1(≤7.18 μg/L) group (n=50), Q2: (>7.18-≤9.39 μg/L) group (n=50), Q3: (>9.39-≤13.74 μg/L) group (50), Q4: (>13.74 μg/L) (n=40). In order to evaluate the effect of calcitriol on platelet aggregation, platelet rich plasma (PRP) in healthy group (15 cases) and clopidogrel resistance group (15 cases) were treated with calcitriol (10 nmol/L) and saline (37 ℃ pretreatment for 5 minutes), respectively, and to compare the difference of maximum platelet aggregation rate induced by ADP between the two treatments. Results There were significant differences in ADP-induced maximum platelet aggregation rate (MPAR) ((49.36±23.34)%, (48.80±20.90)%, (37.02±18.24)%, (36.02±14.46)%, F=3.426, P=0.018) and clopidogrel resistance (CR)/ clopidogrel sensitive (CS) ratio (30/20, 24/26, 15/35, 10/30, χ2=15.119, P=0.002) among the vitamin D quartiles (increasing). Moreover, the MPAR and CR showed a decreasing trend with the increase of vitamin D concentration.Logistic regression analysis showed that serum 25(OH)D level was an independent inhibited factor for clopidogrel resistance in elderly patients with ischemic stroke (Q4 vs Q1, OR=0.699, 95%CI 0.582~0.838, P<0.001; Q3 vs Q1, OR=0.848, 95%CI 0.755-0.953, P=0.006). In vitro, compared with physiological saline, the aggregation rates of platelet in healthy group and CR group decreased after calcitriol pretreatment, and the difference was statistically significant(healthy group: (69.8±12.7)% vs (58.6±11.5)%, t=12.13, P<0.001; CR group: (65.5±8.3)% vs (56.3±7.6)%, t=11.48, P<0.001). Conclusion Vitamin D reduces the high residual platelet reactivity after antiplatelet therapy.Further study is needed to determine whether vitamin D supplementation may improve the efficacy of clopidogrel. Key words: Ischemic stroke; Antiplatelet therapy; Vitamin D; Drug resistance

Effect of Furostanol Saponins from Allium Macrostemon Bunge Bulbs on Platelet Aggregation Rate and PI3K/Akt Pathway in the Rat Model of Coronary Heart Disease.

Aim. To investigate the effect of Furostanol Saponins from Allium Macrostemon Bunge Bulbs (FSAMB) on platelet aggregation rate of rats with coronary heart disease and discuss the mechanism of FSAMB affecting the platelet aggregation rate through PI3K/Akt pathway. We established the rat models with coronary heart disease (CHD) and prepared the platelet-rich plasma. The effect of different concentrations of FSAMB on platelet aggregation in SD rats induced by ADP was observed in vitro and in vivo. And Lactate Dehydrogenase (LDH), Creatine Kinase-MB Form (CK-MB), and Cardiac Troponin I (cTnI) are detected in the blood to know the level of damage to heart cells. The expansion of platelets in the immobilized fibrinogen in different concentrations of FSAMB was observed. Western blot was conducted to detect the phosphorylation level of protein kinase B (also known as Akt) and the expression level of phosphoinositide 3-kinase (PI3K). We found that FSAMB had a significant inhibitory effect on the ADP-induced platelet aggregation in vitro. Intragastric administration of FSAMB also inhibited platelet aggregation induced by ADP in rats. LDH, CK-MB, and cTnI levels in serum of rats in FSAMB (672 mg/kg) group were lower than those in the model control group after the intervention (P<0.01 or P<0.05). FSAMB inhibited the expansion of platelets on immobilized fibrinogen. Also, FSAMB inhibited ADP-induced platelet PI3K expression and Akt phosphorylation. The inhibition of Akt phosphorylation by FSAMB was more obvious after the inhibition of the expression of PI3K. This study demonstrated that FSAMB can reduce the degree of myocardial cell damage and inhibit ADP-induced platelet aggregation in SD rats, possibly by inhibiting platelet PI3K/Akt signaling pathway in vitro and in vivo.

Effects on thrombocytic hemostasis of a new derivate indolinone

Objective. Specific activity of an antiplatelet drug of indolinone series (codenamed DI) was studied in vitro in a model of ADP-induced platelet aggregation in vitro and in vivo in a model of streptozotocininduced diabetes mellitus in rats.&#x0D; Material and Methods. Acetylsalicylic acid and dipyridamole were used as reference drugs. In vitro tests have demonstrated that DI exhibits antiplatelet activity in a wide range of concentrations (0,75×10-6 – 1.5×10-5 М, р&lt;0,05), being comparable to acetylsalicylic acid and dipyridamole. In vivo tests have demonstrated dose-dependent antiplatelet activity of DI in doses of 2,5 – 20 mg/kg (21-14 %).&#x0D; Results and Discussion.Increasing the dose of DI above 10 mg/kg doesn’t increase its antiplatelet activity. After multiple oral administration to rats with streptozotocin-induced diabetes mellitus in 10 mg/kg dose, DI has exhibited antiplatelet activity, reducing the platelet aggregation rate to that of the control group (р&lt;0,05).&#x0D; Conclusion. Thus, DI isapromisingcompound for furtherdevelopmentof an antiplatelet drug with new mechanism of action&#x0D; Bangladesh Journal of Medical Science Vol.18(3) 2019 p.574-576

Genotyping and phenotyping CYP3A4\CYP3A5: no association with antiplatelet effect of clopidogrel.

The objective of this study was to determine the impact of polymorphism of CYP3A subfamily isoenzymes (allelic variants of CYP3A4*22 and CYP3A5*3) on the efficacy clopidogrel in patients with an acute coronary syndrome (ACS), who have undergone percutaneous coronary intervention (PCI). Platelet activity was determined on a VerifyNow P2Y12 test system in 81 patients with ACS aged 37-91 who had PCI. The activity of CYP3A4/5 was expressed as the ratio of the concentrations of cortisol and 6β-hydroxycortisol was performed by using high performance liquid chromatography. Genotyping was performed by using real-time polymerase real-time chain reaction. The frequencies for the CYP3A5 gene, rs 776746, were identified as follows: 77 (95.1%)-CC, 4 (4.9%)-CT; the allele frequencies by loci for the CYP3A4, rs rs35599367, were as follows: 78 (96.3%)-GG, 3 (3.7%)-AG. There was no statistically significant genotype-dependent difference between the presence of a minor T and G alleles and the presence of clopidogrel resistance (OR 3.53; 95% CI 0.46-26.94; p = 0.233 and p = 0.443, respectively). The average level of the metabolic relationship (6β-hydroxycortisol/cortisol) between the clopidogrel-resistant group and the normal platelet reactivity group was not statistically significantly different: 3.3 ± 2.8 versus 3.2 ± 3.2; p = 0.947. So, the activity of CYP3A4/5 was not related to platelet aggregation rates in this model. Genotyping and phenotyping CYP3A4\CYP3A5 does not predict the antiplatelet effect of clopidogrel. More extensive research is required to establish their clinical relevance.

EXPERIMENTAL STUDY OF ANTI-THROMBOTIC ACTIVITY OF PENTOXYFILLIN MICROPARTICLES: BASED ON POLY-DL-LACTIDE-CO-GLYCOLIDE IN COMPARISON WITH PENTOXYFILLIN

The aimof the work was a comparative experimental study of the effect of oral administration of Pentoxifylline microparticles based on PLGA, and “standard” Pentoxifylline, on the ADP-induced platelet aggregation process in rats.Materials and methods.Pentoxifylline substance (100 mg/kg) was used as a reference drug, and PLGA-based Pentoxifylline microparticles with an average dynamic radius of 175.4 nт were used as the object in study. In the experiment, male Wistar rats (m = 300–330 g), the same age group (9 months) were used. They were divided into 3 groups, each of 6 animals. The antiplatelet activity was assessed by determining the degree and rate of platelet aggregation in 1, 3, 5, 8 and 24 hours after a single oral administration of the reference drug and the object under study. Adenosine diphosphate (ADP) at the concentration of 5 μM was used as an aggregation inducer. The aggregation process was recorded using a two-channel laser platelet aggregation analyzer ALAT-2, wavelength of 0.785 μm. by determining the average conventional size of the aggregates.Results.The experiment has proved the following: PLGA-based Pentoxifylline microparticles are more effective at reducing the possibility of platelets to aggregate within 24 hours of the investigation (more than 40%) conventional to the control group value. Besides, it should be noted that according to the effectiveness of the pharmacological action during AD-induced platelet aggregation, the microparticles are commensurate with the standard sample - Pentoxifylline. The action of the microparticle object under study lasts for 24 hours, while the effect of the reference drug is over after 3 hours and then the indicators of the reference group do not differ from those of the control onel.Conclusion.When administered per os, PLGA-based Pentoxifylline microparticles prolong the pharmacological effect significantly – up to 24 hours.

Thrombomodulin alfa prevents the decrease in platelet aggregation in rat models of disseminated intravascular coagulation

IntroductionDisseminated intravascular coagulation (DIC), a deadly complication characterized by uncontrolled hypercoagulation, causes a decrease in the platelet count and impairs platelet aggregation. Thrombomodulin (TM) alfa, a recombinant human soluble TM, reduces hypercoagulation in DIC patients. However, the effects of TM alfa on impaired platelet aggregation remain to be determined. In this study, we aim to investigate the effects of TM alfa on platelet aggregation using lipopolysaccharide (LPS)-induced and tissue factor (TF)-induced DIC rat models. Materials and methodsSprague–Dawley rats were administered TF or LPS intravenously, with or without TM alfa before the injection. Six hours after LPS injection or 1 h after TF infusion, blood samples were obtained, and platelet-rich plasma was prepared. Collagen or adenosine diphosphate-induced platelet aggregation was measured using an aggregometer. In the other experiments, platelets were transfused 1 h after the TF infusion. Five minutes after transfusion, collagen-induced platelet aggregation was also measured. ResultsThe amplitude of platelet aggregation in platelet-rich plasma was decreased in LPS- and TF-treated rats. TM alfa inhibited the decrease in platelet aggregation in a dose-dependent manner. The washed platelet aggregation amplitude was not decreased in TF-treated rats. Suspension of normal platelets in plasma obtained from TF-treated rats reduced platelet aggregation. Platelet transfusion for TF-treated rats increased the platelet count but was unable to improve platelet aggregation. ConclusionsTM alfa attenuated impairment of platelet aggregation in LPS- and TF-induced DIC rat models. The changes in plasma composition played a role in the decrease of platelet aggregation in TF-treated rats.

Агрегационная активность тромбоцитов у больных ишемическим инсультом - носителей генетического полиморфизма некоторых толл - подобных рецепторов

Цель - изучение генетического полиморфизма толл-подобных рецепторов при ишемическом инсульте и его влияние на агрегационную активность тромбоцитов. Методика. В исследовании приняли участие 115 больных ишемическим инсультом, в возрасте 55-65 лет и 94 сопоставимых по возрасту здоровых респондента. Материалом для молекулярно-генетического анализа служили образцы ДНК, выделенные из лейкоцитов периферической крови. Первичный гемостаз (спонтанная и индуцированная агрегатометрия) изучался на двухканальном лазерном анализаторе агрегации тромбоцитов АЛАТ-2. Результаты показали, что предикторами ишемического инсульта являются аллели: 753Arg TLR2, 249Pro TLR6, 1237C TLR9 и генотипы 753Arg/Arg TLR2, 299Asp/Asp TLR4, 249Pro/Pro TLR6 с отношением шансов от 1,49 до 3,35. Для развития инсульта имеет значение не только качество полиморфных маркеров, но и количество предикторных аллельных вариантов. У больных ишемическим инсультом в острейший период и в период формирования инфаркта мозга отмечается увеличение скорости и степени спонтанной агрегации тромбоцитов с последующим снижением к концу острого периода. При внесении АДФ (5 и 1,25 мкг/мл) и коллагена наблюдается снижение скорости и степени агрегации на 1-е и 10-е сут инсульта с увеличением таковых к 21-м сут. У больных - обладателей двух и более предиктивных аллелей полиморфизма толл-подобных рецепторов в геноме в динамике инсульта отмечаются сравнительно низкие показатели степени и скорости индуцированной агрегации тромбоцитов с увеличением радиуса агрегатов. Aim. To study genetic polymorphism of toll-like receptors in ischemic stroke and the polymorphism effect on the platelet aggregation ability. Methods. The study involved 115 patients with ischemic stroke aged 55-65 and 94 age-matched healthy respondents. DNA samples isolated from peripheral blood leukocytes were used for molecular genetic analysis of TLR2 (Arg753Gln), TLR3 (Phe412Leu), TLR4 (Asp299Gly), TLR6 (Ser249Pro), TLR9 (T - 1237 C). Primary hemostasis (spontaneous and induced aggregatometry) was studied using an ALAT-2 two-channel laser analyzer of platelet aggregation. Results. The study showed that predictors of ischemic stroke included the 753Arg TLR2, 249Pro TLR6, 1237C, and TLR9 alleles and the -753Arg/Arg TLR2, 299Asp/Asp TLR4, and 249Pro/Pro TLR6 genotypes with odds ratios from 1.49 to 3.35. Not only the quality of polymorphic markers but also the number of predictive allelic variants are important for the development of stroke. In patients with ischemic stroke in the acute phase and during the formation of cerebral infarction, increased rate and degree of spontaneous platelet aggregation were observed with a subsequent decrease by the end of acute period. Addition of ADP (5 and 1.25 mg/ml) and collagen decreased the rate and degree of platelet aggregation on days 1 and 10 of stroke with an increase in both by day 21. In patients carrying two or more predictive alleles of the toll-like receptor polymorphism in the genome, relatively low rate and degree values of induced platelet aggregation with increased radius of the aggregates were observed in the dynamics of stroke

Differential expression of lncRNA in patients with coronary artery disease plus clopidogrel resistance

To explore differential expression of long non-coding RNA (lncRNA) in patients with coronary artery disease plus clopidogrel resistance. Methods: Patients underwent percutaneous coronary intervention (PCI) and treated with clopidogrel were recruited, and their clinical data and blood samples were collected. Patients were divided into a clopidogrel sensitive group and a clopidogrel resistance group according to platelet aggregation rate. lncRNA microarray and real-time RT-PCR were performed in 5 and 34 patients in each group, respectively. Results: lncRNA microarray showed that 11 lncRNAs in peripheral leukocytes were up-regulated and 8 lncRNAs were down-regulated in clopidogrel resistant group. Real-time PCR indicated that two lncRNAs (NONHSAT083775.2 and NONHSAT107804.2) in leukocytes were up-regulated and one lncRNA (NONHSAT133455.2) was down-regulated in the clopidogrel resistant group compared with the clopidogrel sensitive group, consistent with the results of lncRNA microarray. Conclusion: Clopidogrel resistance is associated with the up-regulation of lncRNA NONHSAT083775.2 and NONHSAT107804.2 and the down-regulation of NONHSAT133455.2.

Streptozotocin-Induced Diabetes Mellitus – a Paradox of High Intrinsic Platelet Reactivity and Low In Vitro Platelet Aggregation

Studies of platelet function in diabetics are inconsistent, some studies reporting higher platelet reactivity, while others showed no change. We aimed to evaluate platelet indices and in vitro platelet aggregation in rats with long-lasting (28 weeks) diabetes mellitus. Twelve controls and 14 diabetic rats were investigated. Diabetes was induced in 11-week-old rats using streptozotocin (60 mg/kg,i.p.). Platelet indices and in vitro adenosine diphosphate (ADP)-, protease-activated receptor 4 (PAR4) agonist-, and arachidonic acid (AA)-induced platelet aggregation were assessed at the age of 38 weeks. Compared to controls, diabetic rats presented lower platelet count and plateletcrit (both p≤0.001), and higher mean platelet volume (p<0.01). ADP- (p=0.04) and AA-induced (p<0.01) platelet aggregation were lower in diabetic compared with control rats, whereas PAR4 agonist-induced platelet aggregation was similar between the two groups (p=1.00). This study demonstrates a paradox of high intrinsic platelet reactivity and low in vitro ADP- and AA-induced platelet aggregation in diabetic rats compared with non-diabetic controls. The relevance of in vitro platelet aggregation to the contribution of platelets to in vivo thromboembolic events in diabetic rats remains questionable.

Aspirin in combination with clopidogrel in the treatment of acute myocardial infarction patients undergoing percutaneous coronary intervention.

Objective:To investigate the clinical effect of aspirin combined with clopidogrel on acute myocardial infarction after percutaneous coronary intervention (PCI).Methods:One hundred thirty two patients with acute myocardial infarction who were admitted to the hospital between December 2016 and December 2017 were divided into a control group and an observation group according to random number table, 66 each group. Both groups were given emergency PCI and symptomatic treatment. The control group was given aspirin on the basis of conventional treatment before and after operation, while the observation group was given clopidogrel treatment on the basis of the treatment the same as the control group. The treatment lasted for 4 months. The clinical efficacy of the two groups was analyzed, and the cardiac function indicator, coagulation indicator and occurrence of adverse reactions were compared before and after treatment.Results:There was no thrombosis at the infarct site in coronary angiography after treatment in both groups. The efficacy in the observation group and control group were 89.4% and 81.8%, respectively; there was no significant difference between the two groups. The incidence of re-thrombosis in the two groups was 1.5% and 12.1% respectively, which was significantly lower in the observation group than in the control group (P<0.05). The cardiac function indicator of both groups improved after treatment, especially the observation group (P<0.05). There was no significant difference in prothrombin time (PT), activated partial thromboplastin time (APTT), prothrombin activity (PA) and platelet aggregation rate (PAR) in the two groups before treatment (P>0.05). There was also no significant difference in PT and PA before and after treatment (P>0.05). The APTT and PAR were significantly different after treatment (P<0.05), and the PAR of the observation group was significantly higher than that of the control group (P<0.05). The incidence of adverse reactions in the observation group was 7.58%, which was not significantly different with that of the control group (12.12%) (P<0.05).Conclusion:Aspirin combined with clopidogrel can effectively reduce the occurrence of re-thrombosis after PCI and improve the recovery of cardiac function after acute operation, moreover the safety is high. It has important clinical application values.

Effects of water-soluble tomato concentrate on platelet aggregation

Objective: To investigate the antiplatelet aggregation effect of water-soluble tomato concentrate (WSTC) and explore the underlying molecular mechanisms. Materials and Methods: Platelet aggregometry was used to quantify rat platelet aggregation with the maximum aggregation rate in vitro and ex vivo. Then, the fibrinogen (FIB) binding assay was employed to detect the effect of WSTC on the activation of platelet integrin αIIβ3 (GP IIb/IIIa). Furthermore, Western blot was performed to assess the platelet protein levels of phosphoinositide 3-kinase 110 β (PI3K110 β), protein disulfide isomerase (PDI), platelet endothelial cell adhesion molecule 1 (PECAM-1), and β1-Tubulin. Results: WSTC inhibited adenosine diphosphate (ADP) and collagen-induced platelet aggregation in a concentration-dependent manner in vitro, at IC50values of 3.05 g/L and 8.03 g/L, respectively. Significantly reduced ex vivo ADP induced platelet aggregation was observed after oral consumption of WSTC for 4 weeks in rats; average inhibition rates were 24.42%, 21.48%, and 20.87% for 25 mg/Kg, 75 mg/Kg, and 150 mg/Kg WSTC, respectively. It appeared that WSTC had no influence on coagulation function in rats. Incubation with WSTC decreased FIB binding to GP IIb/IIIa by 17.47% and 32.29% at the concentrations of 0.6 and 6 g/L, respectively. WSTC at 0.6 and 6 g/L markedly downregulated PI3K110 β, PDI, and PECAM-1 in platelets, and upregulated β1-Tubulin, in a concentration-dependent manner. Conclusion: WSTC inhibits platelet activation through modulation of platelet skeletal stability and suppresses GP IIb/IIIa receptor-mediated platelet aggregation, likely via the PI3K signaling pathway and PDI inhibition.

Effect of ABO blood group factor on anticoagulation with aspirin

Objective To evaluate the effect of ABO blood group factor on anticoagulation with aspirin. Methods Seventy-three patients of both sexes, aged 45-70 yr, who did not take aspirin recently, were divided into 4 groups according to the blood group: blood group A group (group A, n=18), blood group B group (group B, n=20), blood group AB group (group AB, n=15), and blood group O group (group O, n=20). Aspirin 100 mg/d was taken orally for 2 weeks.Fasting blood samples were taken from the peripheral vein before administration (T1) and at 2 weeks after administration (T2) for measurement of activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT), fibrinogen (Fib), platelet count (Plt) and platelet aggregation rate. Results There was no significant difference in Plt at T1, 2 or platelet aggregation rate at T1 among the four groups (P>0.05). Compared with A, B and AB groups, PT, APTT and TT were significantly prolonged and Fib was decreased at T1, and platelet aggregation rate was decreased at T2 in group O (P 0.05), and platelet aggregation rate was significantly decreased at T2 in the four groups (P<0.05). Conclusion ABO blood group factor is related to the individual variation in anticoagulation with aspirin, patients of A, B and AB blood group have the same sensitivity to anticoagulation with aspirin, and patients of O blood group are more sensitive to anticoagulation with aspirin. Key words: ABO blood group system; Aspirin; Platelet aggregation

Antithrombotic effects and related mechanisms of Salvia deserta Schang root EtOAc extracts

Salvia deserta Schang (SDS) belongs to the same family as Salvia miltiorrhiza bunge, one of the antithrombotic Chinese herbal medicines. In our study, EtOAc root extracts were analyzed for their effects on adenosine diphosphate (ADP)-induced platelet aggregation in rabbits and FeCl3-induced rat common carotid artery thrombosis as well as on rat blood plasma concentrations of thromboxane B2 (TXB2), 6-keto-prostaglandin F1 alpha (6-keto-PGF1α), antithrombin-III (AT-III), protein C (PC), plasminogen (PLG), plasminogen activator inhibitor (PAI-1), von Willebrand factor (vWF) and tissue-type plasminogen activator (t-PA). EtOAc extracts from SDS roots had significant inhibitory effects on ADP-induced maximum platelet aggregation rate (10.2 ± 2.6 vs control 35.7 ± 5.2; P < 0.05), reduced the FeCl3-induced rat common carotid artery thrombus weight and thrombus area ratio (P < 0.05), significantly decreased plasma TXB2, vWF and PAI-1 levels and increased 6-keto-PGF1α and t-PA levels in a dose dependent manner (all P < 0.05). Thus, the ratio of TXB2/6-keto-PGF1α was significantly decreased (P < 0.05), while the ratio of t-PA/PAI-1 was significantly increased (P < 0.05). In addition, enhanced AT-III and PC activities indicated coagulation inactivation effects of EtOAc SDS root extracts. EtOAc extraction from SDS showed antithrombotic effects, which are likely due to platelet adhesion and aggregation inhibition as well as anticoagulant activities.

Biological activity and hydroxy safflor yellow A content of intermediates in preparation of Safflower Injection

In order to investigate the effect of various production processes on the quality of Safflower Injection, the biological activities of the intermediates were evaluated by measuring activated partial thromboplastin time (APTT) and adenosine diphosphate (ADP) induced platelet aggregation in vitro. Intermediates were produced by key processes, such as extraction, concentration, twice alcohol precipitation, water sedimentation and two sterilizations during the production of Safflower Injection. The content of main chemical components in intermediates was determined by HPLC. The results showed that with the advance of the preparation process of Safflower Injection, the inhibition of ADP-induced platelet aggregation rate of each intermediate decreased gradually, and the trend of extending APTT activity decreased first and then increased. Meanwhile, the content of hydroxy safflor yellow A (HSYA) was gradually lowered, the content of p-hydroxy-cinnamic acid was increased, and new chemical component p-hydroxybenzaldehyde was produced. In conclusion, sterilization played a key role in the biological activity and HSYA content of Safflower injection.

Further Evidence for Hypercoagulability in Women With Ovarian Endometriomas.

Our previous studies have shown that platelets play a crucial role in the development of endometriosis, and women with endometriosis appear to be in a state of hypercoagulability. However, a recent study could only replicate part of our previous finding, casting doubts on this notion. We further investigated this question through a cross-sectional study by measuring additional coagulation factors in women with and without endometriosis. To this end, we conducted a cross-sectional study of 100 women with laparoscopically and pathologically diagnosed ovarian endometriomas (OMA) and another 100 women without endometriosis. The platelet count; platelet activation rate; maximum platelet aggregation rate; plasma levels of D-dimer, fibrinogen, fibrin degradation products (FDPs), plasma soluble P-selectin (sP-sel), and prothrombin fragment 1+2 (F1+2); prothrombin time; thrombin time (TT); and activated partial thromboplastin time were measured before surgery and 3 months after surgery, and their clinical data were recorded. These measurements were also performed in control patients. We found that, compared with controls, women with OMA had a significantly higher platelet activation rate and platelet aggregation rate, elevated plasma D-dimer, fibrinogen, FDPs, sP-sel, and F1+2 levels as well as shortened TT. Remarkably, TT was prolonged, and all the other coagulation measurements, except plasma fibrinogen level, were significantly reduced 3 months after surgical removal of endometriotic lesions. Thus, our study provides another piece of evidence that endometriosis is a hypercoagulable disease, and anticoagulation therapy may hold promises in treating endometriosis.

Platelets enhance the ability of bone-marrow mesenchymal stem cells to promote cancer metastasis.

BackgroundBone marrow-derived mesenchymal stem cells (BM-MSCs) have been identified to be closely associated with cancer progression. Our previous experimental results showed that BM-MSCs promote tumor growth and metastasis of gastric cancer through paracrine-soluble cytokines or exosomes. However, the elements that affect the role of BM-MSCs in promoting tumor metastasis are not clear. It is known that thrombocytosis in cancer patients is very common. Recently, platelets are recognized to play a critical role in tumor progression.PurposeThis study aims to observe the effect of BM-MSCs which were co-cultured with platelets on tumor cell metastasis.MethodsPlatelet aggregation rate and the expression of P-selectin of platelets co-incubated with conditioned medium of SGC-7901 cells and BM-MSCs were detected by flow cytometry and platelet aggregometer. We also analyzed the change of BM-MSCs after co-incubation with platelets or platelets which were treated with SGC-7901 cells using transwell assay and Western blot analysis. The proliferation and migration ability and expression of VEGF, c-Myc, and sall-4 in SGC-7901 cells treated with medium of BM-MSCs which were co-cultured with platelets were detected. SGC-7901 cells were injected into Balb/c nude mice and the extent of lung metastasis was observed. Both in vitro and in vivo assays were used to analyze the effect of platelets on enhancing the ability of BM-MSCs to promote cancer metastasis.ResultsResults suggested that BM-MSCs and tumor cells can promote platelet aggregation rate and the expression of P-selectin. The protein levels of α-smooth muscle actin, vimentin, and fibroblast activation protein in BM-MSCs were higher after co-incubation with platelets, and SB431542 was used to confirm the effect of TGF-β on transdifferentiation of BM-MSCs into cancer-associated fibroblasts. Medium of BM-MSCs treated with platelets enhanced the proliferation and migration ability of SGC-7901 cells. More lung metastases were found in mice which were injected with SGC-7901 cells treated with conditioned medium from BM-MSCs co-incubated with platelets.ConclusionTumor cells and BM-MSCs activate platelets which can change the characteristics of BM-MSCs through secretion of TGF-β. Moreover, we found that platelets enhanced the effect of BM-MSCs on tumor metastasis, which suggested a potential target and approach for gastric cancer therapy.

Effect of flurbiprofen axetil for postoperative analgesia on blood coagulation: a meta-analysis

Objective To analyze the effect of flurbiprofen axetil (FA) on blood coagulation in patients undergoing surgery through systematic review and meta-analysis. Methods PubMed, WanFang and CNKI databases were searched from their establishment to August 2017 by computer retrieval for relevant literature on the blood coagulation effect of FA. The references of the studies included were also searched by hand. Two reviewers independently screened the literature, extracted data from full-text articles, and evaluated the methodological quality of included studies. All data were analyzed by Review Manager 5.3. Results Altogether 11 studies were finally included, consisting of 10 RCTs and one case-control study, involving 643 patients undergoing surgery. The mean Jadad score for all the studies included were less than 3, suggesting low methodological quality of the studies included. The pool analysis of 4 blood coagulation indexes (prothrombin time, thrombin time, activated partial thromboplastin time and fibrinogen) and platelet count showed that there were no significant differences between the control group and flurbiprofen axetil group before treatment and at 30 min, 1-2 h, 6-8 h, 12 h, 24 h and 48 h after treatment (P>0.05) . As for other outcomes like Sonoelot coagulation indexes [activated clotting time of whole blood, coagulation rate and platelet function (PF)], time to peak, mean platelet volume, maximum platelet aggregation rate, platelet aggregation rate at 1 min (PAG1), platelet aggregation rate at 5 min (PAG5) and platelet aggregation rate maximum, no significant differences were found except in one study where PF was found to be lower at 2 h after treatment in the FA group than in the control group. Conclusion Use of FA in common clinical doses is safe for postoperative analgesia, because blood coagulation may not be significantly affected. Key words: Systematic review; Analgesia; Posoperative period; Flurbiprofen axetil; Blood coagulation

Correlation of CYP2C19 polymorphism and clopidogrel efficacy after percutaneous coronary intervention in Zunyi of Guizhou province

Objective To investigate the relationship between CYP2C19 gene polymorphisms and clopidogrel efficacy in coronary heart disease patients after percutaneous coronary intervention (PCI). Methods From January 2016 to December 2017, 62 patients with acute coronary syndromes and treated with PCI in Guizhou Aerospace Hospital were recruited, CYP2C19 genotype, ADP-induced platelet aggregation rate and myocardial enzymes and other indicators were detected before operation.The myocardial enzymes were measured 24 hours after PCI.According to different metabolic types, the patients were grouped, the above indicators were compared. Results The CYP2C19*1/*1 was 37.10%, CYP2C19*1/*2 was 35.48%, CYP2C19*1/*3 was 11.29%, CYP2C19*2/*2 was 12.90%, CYP2C19*2/*3 was 3.23% and CYP2C19*3/*3 was 0.00%.The LDH, AST, CK, CK-MB and α-HBDH in the PCI patients after operation were significantly higher than those before operation(t=0.019, 0.040, 0.044, 0.022, 0.014, all P 0.05). Conclusion CYP2C19 mutation frequency in the Chinese population is relatively large, the sample size of this study is less, the relationship between clopidogrel resistance and the specific genotype can not be obtained, it need to increase the sample size and comprehensive multi-factor consideration. Key words: Percutaneous coronary intervention; Gentype; Cytochrome P-450; Clopidogrel

Reduced nicotinamide adenine dinucleotide phosphate inhibits rat platelet aggregation and p38 phosphorylation

Previous studies found that reduced nicotinamide adenine dinucleotide phosphate (NADPH) protected neurons against ischemia/reperfusion-induced injury. In addition to ROS reduction and ATP increment, preliminary data suggested that NADPH inhibited ADP and thrombin-induced platelet aggregation. As the effect of NADPH on platelet function was not reported by other investigators, the actions of NADPH on platelet function and mechanisms of actions were investigated in the present study. In vitro studies, the effects of different concentrations of NADPH on platelet aggregation induced by ADP (10 μM), thrombin (0.05 U/mL) or AA (50 μM) were determined. The results showed that NADPH could inhibit platelet aggregation induced by ADP, thrombin or AA in a concentration dependent manner. When the inhibitory effects of NAD+, NADH, NADP+ and NADPH on platelet aggregation were compared, NADPH demonstrated the relatively best effect on platelet aggregation. In vivo studies, the effects of NADPH on platelet aggregation, tail bleeding time, coagulation response and ferric chloride-induced thrombosis were determined in mice or rats. The maximum aggregation rate of platelets of rats injected with NADPH (5 mg/kg) was lower than platelets from control rats. NADPH transiently prolonged tail bleeding time in mice at 30 min after the injection of NADPH (7.5 mg/kg), while aspirin (15 mg/kg) significantly prolonged the tail bleeding time in mice at all time points examined. NADPH (5 mg/kg), as well as aspirin (10 mg/kg), had no effect on coagulation response in rats. Using a FeCl3-induced abdominal aorta injury thrombosis model, administration of NADPH (5 mg/kg) significantly delayed the onset of vessel occlusion, while aspirin (10 mg/kg) almost completely prevented the vessel occlusion. With microscopic examination the thrombi in injured vessel sections of rats received NADPH were much smaller and less dense than that of rats received vehicle treatment. ADP induced an increase in phosphorylation of p38 and the effect was markedly inhibited by the p38 inhibitor SB203580. Similarly, NADPH also inhibited ADP-induced phosphorylation of p38. Similar to NADPH, SB203580 robustly inhibited ADP- and thrombin-induced platelet aggregation. In addition, NADPH also reduced ADP-induced increases in ROS in platelets. The current results demonstrated that NADPH inhibited platelet aggregation, oxidative stress and p38 phosphorylation, suggesting that NADPH might be a novel compound for management of high risk of cardiovascular disease.