Vascular dysfunctions and platelet activations by arsenic: two major contributing factors to cardiovascular disease

Arsenic in drinking water is a worldwide health problem that is associated with cardiovascular disease, but the cause is currently unknown. In order to examine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on agonist-induced vasorelaxation and vasoconstriction using the isolated rat aortic rings in in vitro organ bath system. Treatment with inorganic arsenite (AsⅢ) inhibited acetylcholine-induced relaxation of aortic rings by inhibiting production of nitric oxide in endothelium.

A Notable Platelet Activation Receptor--CLEC-2

In 1995,Huang et al.reported that rhodocytin,asnake toxin purified from callosdasma rhodostoma venomstimulates platelet aggregation.Ten years later,Suzuki-Inoue et al.identified C-type lectin-like receptor 2(CLEC-2)on platelets as the rhodocytin receptor.Thereafter,several studies have showed that platelet CLEC-2 isinvolved in lymphatic/blood vessel separation,tumormetastasis and thrombus formation.

Elevated Platelet Activating Factor Level in Ischemia-Related Arrhythmia and Its Electrophysiological Effect on Myocardium

Objective The mechanism through which platelet activating factor （PAF） induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction （AMI） and the underlying mechanism. Methods （1） Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram （ECG） was recorded continuously. （2） Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. （3） PAF perfusion and standard microelectrode recording were performed on guinea pig papillarymuscles. Results In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization （APD 90 ）under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. Conclusion AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.

Sequential expression of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor in rat hippocampal neurons after fluid percussion injury

Traumatic brain injury causes gene expression changes in different brain regions. Occurrence and development of traumatic brain injury are closely related, involving expression of three factors, namely cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. However, little is known about the correlation of these three factors and brain neuronal injury. In this study, primary cultured rat hippocampal neurons were subjected to fluid percussion injury according to Scott’s method, with some modifications. RT-PCR and semi-quantitative immunocytochemical staining was used to measure the expression levels of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. Our results found that cyclooxygenase-2 expression were firstly increased post-injury, and then decreased. Both mRNA and protein expression levels reached peaks at 8 and 12 hours post-injury, respectively. Similar sequential changes in glutamate receptor 2 were observed, with highest levels mRNA and protein expression at 8 and 12 hours post-injury respectively. On the contrary, the expressions of platelet activating factor receptor were firstly decreased post-injury, and then increased. Both mRNA and protein expression levels reached the lowest levels at 8 and 12 hours post-injury, respectively. Totally, our findings suggest that these three factors are involved in occurrence and development of hippocampal neuronal injury.

In vitro effects of buyang huanwu decoction and its ingredients on inhibiting the specific binding of ~3H-platelet activating factor to its receptor in rabbits

BACKGROUND： Pharmacologic action of traditional Chinese medicine compound is the comprehensive effect of various ingredients, and the interactions of various ingredients are closely correlated with the final effect. In order to reveal the compatibility mechanism of buyang huanwu decoction （BHD）＇s prescription in treating and preventing ischemic cerebrovascular disease, we need to explore the effect and relation of ingredients in prescription except for considering the effect of each ingredient on the whole prescription. OBJECTIVE： To study the effect of BHD and its ingredients in the prescription on the specific binding of 3H-platelet activating factor （PAF） to its receptor （PAFR）in rabbits in vitro, and to analyze the action of each ingredient in the prescription. DESIGN： A decomposed recipe study based on orthogonal test. SETTING： Guangzhou University of Traditional Chinese Medicine. MATERIALS： Five healthy adult New Zealand rabbits of either gender were provided by the Experimental Animal Center of Guangzhou University of Traditional Chinese medicine. The prescription herbal pieces were purchased from Foshan Kangpu Pharmaceuticals Company and Jianmin Pharmaceuticals Company, and were appraised by Professor Yanchen Xu from College of Traditional Chinese Medicine, Guangzhou University of Traditional Chinese Medicine. 3H-PAF was supplied by Amersham Co,Ltd.（Specific activity： 6.475 TBq/mmol;batch number：200402）; PAF standard by Biomol Co., Ltd.（batch number： P1318V）. METHODS： This experiment was carried out in the Laboratory of Nuclear Medicine, Guangzhou University of Traditional Chinese Medicine between September and December 2004. ①The seven influencing factors were selected： such as Shenghuangqi , Dangguiwei, Chishao, Dilong, Taoren, Honghua, Chuanxiong. Each factor was divided into two levels, selected or not selected. The tests were arranged according to L8 （27） orthogonal test table. ②The specific binding of 3H-PAF to its receptors in rabbits was measured by radioligand binding assay. The inhibitory rate of the specific binding was used as an assessing index. The inhibitory action of and on 3H-PAF to PAFR binding was analyzed and compared in vitro. The inhibitory action of each ingredient in the prescription BHD on 3H-PAF to PAFR binding was investigated and compared in vitro by direct analysis and analysis of variance of orthogonal test. MAIN OUTCOME MEASURES： Effect of 8 prescriptions for L8 （27） orthogonal test table on the specific binding inhibition rate of 3H-PAF and PAFR. RESULTS： According to results of variance analysis of orthogonal test, the inhibitory action of each ingredient in the prescription BHD on 3H-PAF to PAFR binding from the highest to the lowest was in turn Honghua, ShenghuangqL Taoren, Dilong, DangguiweL Chuanxiong, Chishao. Honghua, Shenghuangqi, Taoren, Dilong, Danguiwei were major influence factors to 3H-PAF to PAFR in rabbits （F = 187.829,144.446,59.521,5.018,4.265, P 〈 0.05- 0.01）, but Chuanxiong and Chishao had not obviously inhibitory effect. The specific binding inhibition rate of prescriptions （except Shenghuangqi ） was obviously higher than that of one of prescriptions （Shenghuangqi included）. CONCLUSION： The results of orthogonal test show that Honghua, ShenghuangqL Taoren, Dilong, Dangguiwei are major influencing factors to inhibit binding of sH-PAF to PAFR in rabbits, among which, Honghua is the strongest in ingredients of prescription BHD. The results also reveal that Shenghuangqi is able to weaken the inhibitory effect and to prevent the strong inhibitory effect of blood-activating drugs in BHD.

Effects of Buyang Huanwu decoction and Astragalus mongholicus on platelet activating factor receptor activity in rabbits in vitro

BACKGROUND: The pharmacological action of traditional Chinese medicine compound is the comprehensive effect of the various ingredients, and the interactions of various ingredients are closely correlated with the final effect. In order to reveal the compatibility mechanism of BHD's prescription in treating and preventing ischemic cerebrovascular disease, we needed explore the effect and relation of ingredients in the prescription. OBJECTIVE: To observe the effect of Buyang Huanwu decoction (BHD) and Astragalus mongholicus on the activity of platelet activating factor receptor (PAFR) in the platelet of rabbits in vitro, and investigate the mechanism of Astragalus mongholicus. DESIGN: A decomposed recipes study. SETTING: Guangzhou University of Traditional Chinese Medicine. MATERIALS: Five New Zealand rabbits, weighing 2-3 kg, both sexes, were used. BHD was composed of Sheng Huang Qi 120 g, Dang Gui Wei 6 g, Chi Shao 4.5 g, Chuan Xiong 3 g, Di Long 3 g, Tao Ren 3 g, Hong Hua 3 g. The prescription for activating blood circulation consisted of Dang Gui Wei 6 g, Chi Shao 4.5 g, Chuan Xiong 3 g, Di Long 3 g, Tao Ren 3 g and Hong Hua 3 g. The prescription for invigorating qi consisted of 120 g Sheng Huang Qi. The prepared herbal pieces were purchased from the traditional Chinese medicine Dispensary of Foshan Second People's Hospital, and appraised by Professor Xu from Science of Chinese Materia Medica College, Guangzhou University of Traditional Chinese Medicine. 3H-PAF was supplied by Amersham Co., Ltd. (specific activity: 6. 475 TBq/mmol; batch number: 200402); PAF standard by Biomol Co., Ltd. (batch number: P1318V). METHODS: The experiments were carried out in the Laboratory of Nuclear Medicine, Guangzhou University of Traditional Chinese Medicine from September to December 2004. ① Injections of BHD, prescriptions for activating blood circulation and invigorating qi were prepared by the decoction and alcohol sedimentation technique. Rabbit common carotid artery blood (40 mL) was drawn via intubation to prepare platelet suspension of (0.8-1.0)×1010 L-1. ② Determination of 3H-PAF and washed PAFR binding: The general combination tube (T) contained washed platelet-rich plasma (WPRP) 380 μL + 3H-PAF (0.35 nmol/L)10 μL+distilled water 5 μL; The nonspecific binding tube (P) contained WPRP 380 μL+3H-PAF(0.35 nmol/L)10 μL+cold PAF (1 μmol/L) 5 μL; The sample tube (Y) contained WPRP 380 μL+3H-PAF(0.35 nmol/L)10 μL+experimental medicine (injection of BHD, prescriptions for activating blood circulation or invigorating qi) 5 μL. The test was conducted for three times for each sample in the same way as mentioned above. The samples were shaken on the oscillator for 30 s, then bathed at 25 ℃ for 40 minutes, and the reaction was terminated with cold Tris buffer containing 0.1% BSA, multichannel cell detachment separator was used for vacuum suction to filter the separated free 3H-PAF, and the filter paper was washed with cold Tris buffer for four times, then dried in the baking oven (80 ℃) for 1 hour, and placed in xylol liquid scintillator, and the radioactivity was determined automatically by the liquid scintillation detector. The mean of the three parallel tubes was calculated. The specific binging inhibition rate was calculated: SBIR=[(T-Y)/(T-P)]×100%]. ③ Univariate analysis of variance was conducted. And for comparison of each paired groups, the q test was adopted. MAIN OUTCOME MEASURES: Effect of BHD whole prescription, prescriptions for activating blood circulation and invigorating qi on the specific binding inhibition rate of 3H-PAF and PAFR. RESULTS: BHD, prescriptions for activating blood circulation and invigorating qi were all able to inhibit the specific binding of 3H-PAF to PAFR, the specific blinding inhibition rates were (45.90±7.50)%, (97.90±1.84)% and (26.75±2.48)%, respectively, and there were significant differences between every two groups (P < 0.01). CONCLUSION: Single Astragalus mongholicus (120 g) can inhibit the specific blinding of PAFR in the platelet of the rabbit with 3H-PAF, but the combination of Astragalus mongholicus with the drugs for activating blood circulation in BHD can significantly decrease the inhibiting action of the latter on PAFR activity of the platelet, reflecting the combined mechanism of 'removing blood stasis without injuring the vital qi' in BHD.

Whole blood platelet aggregometry in HIV-infected patients on treatment with abacavir

Purpose: To assess platelet activity in HIV-patients with and without antiretroviral therapy (ART), analysing the influence of the presence or absence of ABC in the regimen. Methods: Observational, pilot study, including 30 asymptomatic HIV-patients: 20 on ART for at least 24 weeks and with undetectable HIV viral load - 10 on ABC, 10 on tenofovir (TDF) - and 10 na?ve patients, and a control group of 10 HIV-negative subjects. No subject was receiving drugs with antiagregant activity. Platelet activity was assessed by measuring time-dependent platelet aggregometry (electrical impedance on fasting whole blood), induced by ADP (1.25, 2.5 μM), collagen (0.5, 1 μg/mL), arachidonic acid (100, 200 μM), and U46619 (receptor agonist of the tromboxano A2) (1.25, 2.5 μM). Statistic program: SPSS, 16.0. Results: Demographic, anthropometric data, and cardiovascular risk factors were similar in all groups, but older age and longer time of HIV infection in the ABC group (50.4 vs 36.1, 34.2 and 42.7 years, respectively;p < 0.05, and 140.3 vs 88.1 and 48.3 months in the two other groups of HIV patients;p < 0.05). Mean CD4 cells count was 564/mm3. Platelet aggregation with exposure to U46619 was higher in the ABC compared with the TDF group (11.1 vs 4.4%;p = 0.007), na?ve patients (11.1 vs 5.7%;p = 0.014), and the HIV-negative group (11.1 vs 6.5%;p = 0.04). These differences remained significant when controlled for age and time of HIV infection. Conclusions: ABC increases platelet aggregability possibly in relation with the receptor of tromboxano. Wider studies are needed to confirm this hypothesis.

Relationship between Platelet Activation Related Factors and Polymorphism of Related Genes in Patients with Coronary Heart Disease of Blood-stasis Syndrome

Objective： To comparatively study the expressive conditions of platelet activation related factors （GPⅠb, GPⅡb-Ⅲa and GMP-140） in healthy subjects and patients with coronary heart disease （CHD） of blood-stasis （BS） or non-blood-stasis （non-BS） syndrome, and to analyze the relationship between the activities of various glycoproteins and the polymorphism of genes. Methods： With case control design adopted, patients with the CHD （40 of BS, 37 of non-BS） and 39 healthy subjects for control, all fitting to the inclusion criteria, were selected in this study. The number of affected coronary branches was recorded by the contrast examination. The mean fluorescence intensity （MFI） of GPⅠb, GPⅡb-Ⅲa, and GMP-140 （CD42b, CD61, CD62p） in patients and healthy persons was measured with flow cytometry, the polymorphism of HPA-3 gene was detected by Taqman probe technique and that of HPA-2 gene was determined by gene sequencing. Results： MFI of CD61 and CD62p was higher in the CHD patients than in the healthy control, which was also higher in patients of BS syndrome than in patients of non-BS syndrome （P〈0.05）; MFI of CD42b was lower in the CHD patients than in the healthy control （P〈0.05）, but showing insignificant difference between BS and non-BS syndrome （P〉0.05）; at the same time, no significant difference of all the above-mentioned three MFI could be found in patients with various numbers of affected coronary branches, neither in patients with different genotypes at GPⅡb HPA-3 and GPⅠb HPA-2 polymorphism loci （P〉0.05）. Conclusion： （1） The activities of GP Ⅱ b-Ⅲa and GMP-140 were obviously increased in the genesis and developing process of CHD and CHD of BS syndrome, and so they could be taken as one of the objective indexes for microscopic diagnosis of BS syndrome. （2） The level of GPⅠb was lower in CHD patients than in healthy persons, but it was not a sensitive indicator for BS syndrome of CHD. （3） Levels of GP Ⅱb-Ⅲa, GPⅠb and GMP-140 were not related with the number of affected coronary branches in CHD patients. （4） The changes in amino-acids expression induced by the two loci brought no significant influence on GPⅠb and GP Ⅱb-Ⅲa activities.

Breast cancer stem-like cells can promote metastasis by activating platelets and down-regulating antitumor activity of natural killer cells

OBJECTIVE:To investigate whether cancer stem cells(CSCs) more efficiently activating platelets and evading immune surveillance than non-CSCs thus promoting metastasis.METHODS:We enriched and identified sphereforming cells(SFCs) and coincubated washed platelets with several platelet activators including collagen,4T1 and SFCs.Platelet-coating tumor cells,platelet activation and TGF-β1 release were analyzed.Then natural kell cells(NK) were incubated with supernatants of different activated platelet samples what we called sample release(SR).The degranulation assay and NKG2 D expression on NK cells were conducted by flow cytometry.Finally tissue factor(TF) expression of SFCs or 4T1 were evaluated by western blot.RESULTS:Breast cancer cell line 4T1 could form spheres in serum-free medium at low adherence.Sphere-forming cells expressed high levels of the CD24-/lowCD44 + stem cell phenotype.Both sphere-forming cells or 4T1 were coated with abundant platelets while sphere-forming cells induced significantly higher expression of platelet activating receptor CD62 p than 4T1 did(P < 0.01).And sphere-forming cells induced platelets to produce more TGF-β1 than 4T1 did(P < 0.01).Furthermore,sample releases induced by sphere-forming cells caused more vigorous inhibition of NK cells antitumor reactivity(P < 0.05) and reduced NKG2 D expression(P < 0.01).The final results showed that sphere-forming cells expressed higher levels of TF than 4T1(P < 0.05).CONCLUSION:Our findings indicate that CSCs could efficiently activate platelets,induce platelets to secrete more TGF-β1,decrease NKG2 D expression and inhibit antitumor activity of NK cell,compared with 4T1.And higher levels of TF expression of CSCs may account for this correlation of CSCs and platelets.

Early local intracoronary platelet activation after drug-eluting stent placement

Background Early local platelet activation after coronary intervention identifies patients at increased risk of acute stent thrombosis （AST）. However, early changes in platelet activation in coronary circulation following drug-eluting stent （DES） implantation have never been reported. Methods In a prospective study of 26 consecutive elective stable angina patients, platelet activation was analyzed by measuring soluble glycoprotein V （sGPV） and P-selectin （CD62P） before and after implantation of either DES or bare metal stent （BMS）. All patients were pretreated with clopidogrel （300 mg loading dose） and aspirin （75 mg orally） the day before the procedure. Blood samples were drawn from the coronary ostium and 10 - 20 mm distal to the lesion site. Results Consistent with the lower baseline clinical risk, the levels of CD62P and sGPV were within normal reference range, both in the coronary ostium and distal to the lesion before percutaneous coronary intervention （PCI） procedure. The levels of CD62P and sGPV did not change significantly （CD62P： （31.1 ± 9.86） ng/ml vs （29.5 ± 9.02） ng/ml, P=0.319 and sGPV： （52.4 ± 13.5） ng/ml vs （51.8 ± 11.7） ng/ml, P=0.674, respectively） after stent implantation when compared with baseline. Changes in these platelet activation markers did not differ between stent types. Conclusions Intracoronary local platelet activation does not occur in stable angina patients before and immediately followina DES implantation when dual anti-Dlatelet is administered.

Effects of hormone replacement therapy on platelet activation in postmenopausal women

Objective To assess the effects of hormone replacement therapy (HRT) on platelet activation in postmenopausal women compared with premenopausal women. Methods The expressions of CD41 and CD62P in fifteen postmenopausal women before and after HRT were detected using flow cytometry (FCM),with fifteen premenopausal women with a mean age of 47 years as controls.Results The expressions of CD41 and CD62P in postmenopausal women were higher than those in the control group. CD62P(%),CD62P(I) and CD41 were reduced from 36.40±5.9,37.75±5.8,and 470.11±74.0 to 27.97±5.6,26.64±4.9,and 303.23±72.8 after six months of HRT ( P <0.05). Conclusions Platelet activation in postmenopausal women was higher than in premenopausal women and was reduced significantly after six months of HRT. HRT may have a favorable effect on reduction of platelet activity.

PLATELET ACTIVATION IN PATIENTS WITH CHRONIC PULMONARY HEART DISEASE EFFECT OF DIPYRIDAMOLE TREATMENT

Plasma levels of /f-thromboglobulin (/?-TG), platelet fac-tor 4(P and platelet aggregation rate (PAR) were measured in remission phase of 15 patients affected with chronic pulmonary heart disease (CPHD). 0-TG, /?-TG / PF4, PF4 and PAR were significantly higher in the patients than in controls (/3<0.01 and 0.05, respectively). After 10 days of treatment with Dipyridamole lOOtng tid, fi-TG, /?-TG / PF4 and PF4 decreased significantly compared with pretreatment values (/><0.01 and 0.05, respectively). The results suggest that in vivo platelet activation is indeed present in patients with CPHD and that dipyridamole can antagonize platelet activation in vivo.

The influence of HDL and purified apoprotein E on platelet activation induced by serotonin

Elevated plasma levels of high density lipoprotein (HDL) are recognized as having a beneficial influence on the progression of atherosclerosis. As platelets are closely involved in atherosclerogenesis, it is difficult to evaluate if the protective effect of HDL is associated with its ability to affect platelet structure and function. Previous studies give conflicting reports concerning the HDL platelet interaction. In our in vitro experiments, washed human blood platelets were preincubated with HDL (100 800 μg/ml) and then stimulated by serotonin (5 Hydroxytryptamine, 1 5 μM), a potent agonist and mediator in the process of atherosclerosis. Aggregatory studies and electron microscopy revealed that HDL could not prevent morphological alterations of blood platelets treated with serotonin. Furthermore, high dosages of HDL led to platelet activation. These findings indicate that HDL may not inhibit agonist induced platelet activation. As HDL is a heterogeneous group of different subclasses with opposite effects on platelet function, it Platelet Research Unit, Institute of Anatomy, University of Münster, Germany (Pfennig O and Dierichs R) Institute of Physiology, Ruhr University Bochum, Bochum, Germany (Liu B) can be concluded that HDL platelet interaction reflects relative concentrations of the particular sample. Our findings suggest that the protective influence of HDL may not be associated with decreased platelet function. Apoprotein E rich subclasses of HDL (HDL 2), particularly HDL enriched apoprotein E (HDL E), inhibit agonist induced platelet activation. In order to enlighten the role of apo E in this process, platelets in suspensions were preincubated with purified apoprotein E (50 400 μg/ml) and then stimulated by serotonin (5 μM). Apoprotein E of 300 μg/ml prevented morphological alterations of blood platelets and suppressed serotonin induced activation. Lower concentrated apoprotein E showed no clear effects. There is evidence that apoprotein E is an important factor in the prevention of atherosclerosis, by enhancing the reversed cholesterol transport to the liver and modifiing the functional status of different cell types such as macrophages and smooth muscle cells. Because results showed effects of apo R on platelet activation, we suggest that apoprotein E may be a principal factor when platelet aggregability is suppressed by HDL subclasses or liposomes and that the antiatherogenic potency of apo E correlates with this process.

Pharmacological action and mechanisms of ginkgolide B

Objective To review the recent research progress in pharmacological actions and mechanisms of ginkgolide B. Data sources Information included in this article was identified by searching of PUBMED （1987-2006） online resources using the key terms ＂ginkgolide B＂, ＂platelet activating factor＂, and ＂pharmacological＂. Study selection Mainly original milestone articles and critical reviews written by major pioneer investigators of the field were selected. Results The key issues related to the pharmacological actions and mechanisms of ginkgolide B were summarized. The ginkgolide B possesses a number of beneficial effects such as anti-inflammatory, anti-allergic, antioxidant, and neuroprotective effects. Meantime, their mechaniams were discussed. Conclusions The Ginkgolide B is the most potent antagonist of platelet activating factor （PAF） and exhibits therapeutic action in a variety of diseases mainly by the PAF receptor.

Research on the Correlation between Platelet Gelsolin and Blood-Stasis Syndrome of Coronary Heart Disease

Objective：To study the distribution of gelsolin in human platelet and plasma,and the association with blood-stasis syndrome（BSS） of coronary heart disease（CHD）.Methods：Sixty patients with CHD（30 in BSS group and 30 in non-BSS group） and 30 healthy subjects（control group） were included in this study.The classification of the syndrome was based on clinical symptoms and signs.Gelsolin concentration in platelet rich plasma（PRP）,platelet poor plasma（PPP）,filamentous actin（F-actin） and group-specific component globulin （Gc-globulin） of PPP were determined by enzyme-linked immunosorbent assay（ELISA）.The fluorescence intensity of CD62p and cytoplasmic calcium（[Ca^（2＋）]_i） in human platelets of patients and healthy persons was measured with flow cytometry.Results：Compared with the control group,gelsolin in PRP of the BSS group increased significantly（P0.01）,while that in PPP of the BSS and non-BSS groups decreased markedly（P0.05）, the CD62p,[Ca^（2＋）]_i of platelet,F-actin,and Gc-globulin of the BSS and non-BSS groups increased significantly （P0.01）.Compared with the non-BSS group,the gelsolin concentration in PRP of BSS group increased significantly（P0.01）,the[Ca^（2＋）]_i of platelet of the BSS group increased markedly（P0.01）,while the F-actin and Gc-globulin of the BSS group had no statistical defference（P0.05）.Conclusions：Gelsolin concentration in PRP was increased and accompanied by the elevated[Ca^（2＋）]_i of platelet in CHD with BSS,while gelsolin in PPP were lowered markedly.We speculate that plasma gelsolin may clear F-actin from circulation,thus resulting in depletion of plasma gelsolin significantly.This,in addition to the increased calcium influx of platelets,may lead to the gelsolin abnormal expression on platelets during the process of BSS in CHD.Therefore,platelet gelsolin may serve as a new potential biomarker and a therapeutic target of BSS in CHD.

Omeprazole affects clopidogrel efficacy but not ischemic events in patients with acute coronary syndrome undergoing elective percutaneous coronary intervention

Background Omeprazole, usually used in the antiplatelet therapy during percutaneous coronary intervention （PCI） in acute coronary syndrome （ACS）, has been reported to increase ischemic events in retrospective studies. However, other clinical trials gave paradoxical results. The aim of this study was to assess the effects of omeprazole on clopidogrel efficacy and clinical events.Methods All patients （n=172） received aspirin （loading dose 300 mg and maintenance dose 100 mg/d） and clopidogrel （loading dose 600 mg and maintenance dose 75 mg/d） during the therapy. They were randomized to receive omeprazole （20 mg/d） or placebo for 30 days. Residual platelet activities in the adenosine 5＇-diphosphate （ADP） pathway were detected on the fifth day after PCI with thrombelastography （TEG）-mapping. The clinical events were recorded after one month.Results According to the five levels of platelet activities, the frequency distributions of the inhibition rates were significantly different （P=0.0062）. However, no significant change was seen in the distribution among the highest or the lowest inhibiting levels （〉95% and 〈30% inhibition rate）. And there were no significant differences （P 〉0.05） in events incidence, while gastra-intesternal bleeding decreased in co-administration of omeprazole.Conclusions Omeprazole significantly blunts clopidogreal efficacy while not exacerbates ischimic events in ACS undergoing PCI. Omeprazaole even can decrease gastra-intestinal bleeding in those patients.

Valsartan Decreases Platelet Activity and Arterial Thrombotic Events in Elderly Patients with Hypertension

Background：Angiotensin type 1 receptor （AT1R） antagonists are extensively used for blood pressure control in elderly patients with hypertension.This study aimed to investigate the inhibitory effects of AT1R antagonist valsartan on platelet aggregation and the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.Methods：Two-hundred and ten patients with hypertension and aged 〉 60 years were randomized to valsartan （n =140） or amlodipine （n =70） on admission.The primary endpoint was platelet aggregation rate （PAR） induced by arachidonic acid at discharge,and the secondary endpoint was the rate of thrombotic events including brain infarction and myocardial infarction during follow-up.Human aortic endothelial cells （HAECs） were stimulated by angiotensin Ⅱ （Ang Ⅱ,100 nmol/L） with or without pretreatment of valsartan （100 nmol/L）,and relative expression of cyclooxygenase-2 （COX-2） and thromboxane B2 （TXB2） and both p38 mitogen-activated protein kinase （p38MAPK） and nuclear factor-kB （NF-kB） activities were assessed.Statistical analyses were performed by GraphPad Prism 5.0 software （GraphPad Software,Inc.,California,USA）.Results：PAR was lower after treatment with valsartan （1 1.49 ± 0.69% vs.18.71 ± 2.47%,P 〈 0.001）,associated with more reduced plasmalevels of COX-2 （76.94 ± 7.07 U/L vs.116.4 ± 15.89 U/L,P 〈 0.001） and TXB2 （1667 ± 56.50 pg/ml vs.2207 ± 180.20 pg/ml） （all P 〈 0.001）.Plasma COX-2 and TXB2 levels correlated significantly with PAR in overall patients （r =0.109,P 〈 0.001）.During follow-up （median,18 months）,there was a significantly lower thrombotic event rate in patients treated with valsartan （14.3% vs.32.8%,P =0.002）.Relative expression of COX-2 and secretion of TXB2 with concordant phosphorylation ofp38MAPK and NF-kB were increased in HAECs when stimulated by Ang Ⅱ （100 nmol/L） but were significantly decreased by valsartan pretreatment （100 nmol/L）.Conclusions：AT1R antagonist valsartan decreases platelet activity by attenuating COX-2/TXA2 expression through p38MAPK and NF-kB pathways and reduces the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.

Effect of Volatile Oil of Amomum on Expressions of Platelet Activating Factor and Mastocarcinoma-related Peptide in the Gastric Membrane of Chronic Gastritis Patients with Helicobacter-pylori Infection

Objective： To observe the effect of volatile oil of amomum （VOA） on the expressions of mastocarcinoma-related peptide （PS2） and platelet activating factor （PAF） in helicobacter pylori- associated gastritis （HPG） and to analyze its potential mechanism. Methods： Eighty patients with HPG were randomly assigned to two groups, 42 patients in the treated group treated with 0.5 mL VOA, thrice per day; and the 38 patients in the control group receiving Western tertiary medicinal treatment. Gastroscopic picture and helicobacter pylori （HP） infection （by quick urease and Warthin- Starry stain） of the gastro-membrane, expressions of PS2 and PAF （by immunohistochemical assay and Western blotting） as well as the contents of aminohexose and phospholipid （by Neuhaus method） in the gastric membrane of all patients were detected before treatment and 4 weeks after treatment. The clinical efficacy in the two groups was compared. Results： The total effective rate in the treated group was 88.1%, which was significantly higher than that in the control group （78.9%, P〈0.05）. After treatment, in the treated group, gastric membranous contents of aminohexose and phospholipid was increased, expression of PS2 elevated but that of PAF lowered, all showing significant difference as compared with those in the control group （P〈0.01）. In the control group, the expressions of PS2 and PAF changed insignificantly. The radical eliminating rate of HP in the treated group and the control group was insignificantly different between them （76.1% vs. 65.8%, P 〉 0.05）. Conclusion： The mechanism of VOA for anti-gastritis might be related with its action in increasing the expression of PS2 and decreasing the expression of PAF, and thus regulating the hydrophobicity of the gastric membrane.

EXPERIMENTAL WORK and RESEARCH Effect of Reduqing(热毒清) on TNF-α,IL-1,IL-6,IL-8 and PAF Levels in Endotoxin-Induced DIC Model of Rabbits

Objective: To study the mechanism of anti-endotoxemic effect of Reduqing Injection (RDQ)and to explore the essence of traditional Chinese 'heat-clearing and detoxifying therapy'. Methods: A disseminated intravascular coagulation (DIC) model was made in rabbits by intravenous injection with E. colt endotoxin. Increased plasma levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8) and platelet activating factor (PAF), as well as the ex-vivo LPS-induced interleukin-1 (IL-1 ) production in peripheral blood monocytes were observed in model (M) group. Results: Same parameters were significantly lower in RDQ and dexamethasone (DXM) groups than those in the M group (P < 0. 01, P < 0. 05). Histopathological examination showed severe damage of the liver, lungs and kidneys in the rabbits of M group, in contrast, only mild affects were seen in the RDQ and DXM groups. Conclusions: RDQ exhibits protective effect on rabbits against endotoxin-induced DIC. The suppression of cytokines and inflammatory mediator PAF by RDQ may play a central role in the inhibition of endotoxin-induced DIC cascade.