bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of platelet activation in several different anticoagulants by the Advia 120 Hematology System, fluorescence flow cytometry, and electron microscopy
Authors: Chapman Sabrinah , Lépine Mariette , Okrongly David , Pujol-Moix Nuria , Hernández Angel , Boughrassa Faiza , Grant Andrew , Ahnadi Charaf 
Published: October 2003

Summary
In vivoplatelet activation results are often confounded by activation induced in vitroduring the preparative procedures. We measured ex vivo(basal) and in vitro(thrombin-induced) platelet activation in sodium citrate, ethylenediaminetetraacetic acid (EDTA), and Citrate Theophylline Dipyridamole Adenosine (CTAD) whole blood specimens. Determinations were made by measurements of platelet density (mean platelet component: MPC concentration) on the Advia 120 Hematology System. The MPC has been previously shown to correlate with a fluorescence flow cytometric method, also determined in this study, using the surface expression of CD62P. Moreover, platelet shape and structure changes in EDTA and CTAD anticoagulated whole blood specimens were characterized by transmission electron microscopy (TEM). Observations made using the Advia 120 Hematology System platelet density parameter, MPC, in the absence of thrombin were 25.7 ± 0.9 g/dl, 27.9 ± 0.9 g/dl and 24.8 ± 1.2 g/dl in sodium citrate, EDTA and CTAD whole blood specimens, respectively. Addition of thrombin induced a significant change in platelet MPC for sodium citrate (21.9 ± 1.9 g/dl; p<0.0001) and EDTA (23.2 ± 0.9 g/dl; p<0.0001) whole blood specimens. In contrast, thrombin had no effect on MPC measured in whole blood taken into CTAD tubes. In vitrofluorescence flow cytometric platelet activation experiments measuring the percentage of platelets expressing anti-CD62P showed increase in sodium citrate specimens from 9.2 ± 7.0 to 55.5 ± 23.1 % (p<0.0001) and in EDTA specimens from 1.9 ± 1.7 to 64.6 ± 12.4 % (p<0.0001) after addition of thrombin. However, in blood taken into CTAD tubes, there was no significant change. Studies on platelets isolated from whole blood in CTAD showed activation by thrombin indicating that platelets in CTAD, while protected in its presence remained functional upon its removal. When observed by TEM over time, platelets in EDTA appear more activated and contain fewer granules than platelets in CTAD. We conclude that CTAD demonstrates in vitroplatelet activation inhibition and may be useful in stabilizing ex vivoplatelet activation. The novel platelet activation parameter, MPC, measured by an automated routine hematology system, using customized proprietary software, may be used in conjunction with CTAD, a stabilizing anticoagulant, to measure the ex vivoplatelet activation state in whole blood specimens. TEM studies verify shape modifications and simultaneous retention of intracellular granules at early post-venipuncture time periods in CTAD specimens.
Hemostatic risk factors in ischemic stroke
Authors: Berger Daniela , Mattle Heinrich , Lämmle Bernhard , Wuillemin Walter , Demarmels Biasiutti Franziska 
Published: October 2003

SummaryThe role played by hemostasis in the pathogenesis of ischemic stroke is still controversial. In the present study, we looked for a possible association of ischemic stroke and high clotting activity of factor II (FII:C), factor V (FV:C), factor VII (FVII:C), factor X (FX:C) and fibrinogen. We investigated 157 non-anti-coagulated patients (86 males, 71 females; median age 41 y, range 16-73 ), who had survived ischemic stroke for at least 2 months, and 193 healthy controls with similar age and sex distribution (104 males, 89 females; median age 39 y, range 19-74). Patients showed significantly higher body mass index, as well as significantly higher prevalence of arterial hypertension, smoking and hyperlipidemia. FV:C (p = 0.05), FX:C (p = 0.04) and fibrinogen (p = 0.05) were higher in patients as compared to controls. In a univariate risk analysis FX:C and FV:C were associated with the relative risk for ischemic stroke showing an odds ratio (OR) of up to 2.8 (95% CI: 1.05-7.6) and 3.4 (95%CI: 1.4-7.9), respectively, for levels above 130%. In a multivariate analysis using a logistic regression model including age, sex, arterial hypertension, smoking habit, diabetes, hyperlipidemia, BMI and the coagulation factors, FV:C was still found to significantly (p=0.03) add to the risk of ischemic stroke. An increase of factor FV:C by 10% was associated with an increase in the relative risk of 19% (95% CI.: 2%-38%). In conclusion, we found a high plasma level of FV:C to be a prevalent (FV:C > 130% in 20/157 patients) and independent risk factor for ischemic stroke.
Platelet membrane glycoprotein polymorphisms do not influence the clinical expressivity of von Willebrand disease type 1
Authors: Quiroga Teresa , Pereira Elisa , Morales María , Goycoolea Manuela , Hidalgo Patricia , Prieto Carolina , Mezzano Diego , Pereira Jaime 
Published: October 2003

SummaryVon Willebrand disease (VWD) is characterized by a significant variation in bleeding symptoms among patients with similar laboratory profiles and equivalent plasma levels of von Willebrand factor (VWF) activities. Considering the recent suggestion that platelet membrane glycoprotein polymorphisms (PltGPs) may play a role as modulators of thromboembolic or haemorrhagic diseases, we investigated the role of different PltGPs and GPVI content in the clinical expression of patients with VWD type 1. The diagnosis of VWD (n = 76) was based on laboratory findings (VWF:Ag, VWF:RCo, VWF:CB, FVIII:C, and multimer analysis), family and personal history of bleeding. All patients were interviewed using a standardized questionnaire, and classified into two categories: bleeders (unequivocal bleeding tendency, n = 53) and non bleeders (absence of bleeding symptoms, n = 23). PltGPs, HPA-1, 2 and 5 and C807T of GPIa were determined by fluorophore-labelled hybridization probes on a LightCyclerTM. GPVI content was measured by western blotting.VWF:Ag, VWF:RCo, VWF:CB and FVIII:C levels were not significantly different between symptomatic and asymptomatic patients. There were no differences in the genotype distribution and allele frequencies between bleeders and non bleeders for the platelet alloantigen systems HPA-1, 2, 5 and the GPIa C807T polymorphism. The levels of platelet GPVI were similar in symptomatic and asymptomatic VWD patients (109.6 ± 58.4 vs 114.1 ± 52.5, respectively; p: 0.77). These results show that PltGPs HPA-1, 2 and 5 or the C807T dimorphism of GPIa do not influence the clinical expressivity of VWD type 1. The wide variation in GPVI content was not associated with the severity of bleeding in the patients. Other genetic factors that may contribute to the variable expressivity of VWD type 1 should be investigated.
Antiinflammatory activity of astragaloside IV is mediated by inhibition of NF-κB activation and adhesion molecule expression
Authors: Zhang Wei-Jian , Hufnagl Peter , Binder Bernd , Wojta Johann 
Published: October 2003

SummaryThe regulated expression of adhesion molecules on the surface of endothelial cells is a key process in the pathogenesis of inflammation. The saponin astragaloside IV (AS-IV), a 3-O-β-D-xylopyranosyl-6-O-β-D-glucopyranosylcycloastragenol purified from the Chinese medical herb Astragalus membranaceus(Fisch) Bge.has been shown to have anti-inflammatory effects in vivo.In this study we have investigated the effect of AS-IV on cytokine-and LPS-stimulated expression of adhesion molecules in and leukocyte adhesion to endothelial cells. We have demonstrated that AS-IV significantly reduced the adhesion promoting activity of LPS-stimulated HUVECs for polymorph-nuclear leukocytes (PMNs) and the monocytic cell line THP-1. Furthermore, by using specific cell ELISAs we could show that AS-IV decreased the LPS-induced expression of E-selectin and VCAM-1 on the surface of HUVECs in a dose and time dependent manner, whereas the expression of ICAM-1 was not affected by AS-IV. AS-IV also inhibits TNFβ-induced VCAM-1 expression. The saponin octyl-D-glucopyranoside had no effect on the LPS-induced expression of E-selectin and VCAM-1 excluding an unspecific detergent-like effect of AS-IV. Moreover, AS-IV significantly inhibited LPS- and TNFβ-induced specific mRNA levels for E-selectin and VCAM-1. Finally, we could show that AS-IV completely abolished LPS- and TNFα-induced nuclear translocation of NF-κB and NF-κB DNA binding activity in endothelial cells. We conclude that the ability of AS-IV to inhibit the NF-κB pathway might be one underlying mechanism contributing to its anti-inflammatory potential in vivo.
Exclusion of pulmonary embolism using C-reactive protein and D-dimer
Authors: Hayoz Daniel , Yersin Bertrand , Perrier Arnaud , Barghouth Ghassan , Schnyder Pierre , Bischof-Delaloye Angelika , Cornuz Jacques , Aujesky Drahomir 
Published: October 2003

SummaryOur goal was to evaluate the diagnostic utility of C-reactive protein (CRP) alone or combined with clinical probability assessment in patients with suspected pulmonary embolism (PE), and to compare its performance to a D-dimer assay. We conducted a prospective study in which we performed a common immuno-turbidimetric CRP test and a rapid enzyme-linked immunosorbent assay (ELISA) D-dimer test in 259 consecutive outpatients with suspected PE at the emergency department of a teaching hospital. We assessed clinical probability of PE by a validated prediction rule overridden by clinical judgment. Patients with D-dimer levels ≥ 500 µg/l underwent a work-up consisting of lower-limb venous ultrasound, spiral computer-ized tomography, ventilation-perfusion scan, or pulmonary angiography. Patients were followed up for three months. Seventy-seven (30%) of the patients had PE.The CRP alone had a sensitivity of 84% (95% confidence interval [CI).: 74 to 92%) and a negative predictive value (NPV) of 87% (95% CI: 78 to 93%) at a cutpoint of 5 mg/l. Overall, 61 (24%) patients with a low clinical probability of PE had a CRP < 5 mg/l. Due to the low prevalence of PE (9%) in this subgroup, the NPV increased to 97% (95% CI: 89 to 100%). The D-dimer (cutpoint 500 µg/l) showed a sensitivity of 100% (95% CI: 95 to 100%) and a NPV of 100% (95% CI: 94 to 100%) irrespective of clinical probability and accurately rule out PE in 56 (22%) patients. Standard CRP tests alone or combined with clinical probability assessment cannot safely exclude PE.
Intracellular alkalinization augments capacitative Ca2+ entry in platelets
Authors: Marumo Mikio , Wakabayashi Ichiro 
Published: October 2003

SummaryIn order to elucidate the significance of intracellular alkalinization in signal transduction of platelets, we investigated the effects on capacitative Ca2+ entry (CCE) of intracellular alkalinization that was induced by NH4Cl. Addition of NH4Cl (10 mM) to the medium resulted in an elevation of intracellular pH by about 0.35, which was eliminated by simultaneous addition of propionate (20 mM), an inducer of intracellular acidification, to the medium. CCE was induced by an extracellular addition of Ca2+ to platelets in which Ca2+ stores had been depleted by stimulation with thapsigargin in nominally Ca2+-free medium. NH4Cl markedly augmented CCE and subsequent platelet aggregation, both of which were abolished in the presence of SKF-96365, an inhibitor of capacitative Ca2+ entry in non-excitable cells such as platelets. The augmentation of CCE and subsequent aggregation by NH4Cl was not observed in the presence of propionate or SKF-96365. Extracellular alkalosis induced by Tris also markedly augmented CCE and subsequent aggregation. These augmenting effects of extracellular alkalosis by Tris were significantly but incompletely inhibited by simultaneous addition of propionate (20 mM), which completely eliminated elevation of intracellular pH elicited by Tris. Thus, the augmenting effect of extracellular alkalosis on CCE was in part mediated by intracellular alkalosis. These findings suggest that intracellular alkalinization is a potent signal that augments CCE in platelets.
The effects of different alcoholic drinks on lipids, insulin and haemostatic and inflammatory markers in older men
Authors: Lowe Gordon , Shaper Gerald , Whincup Peter , Rumley Ann , Walker Mary , Lennon Lucy , Goya Wannamethee Sasiwarang 
Published: October 2003

SummaryLight to moderate drinking is associated with lower risk of coronary heart (CHD) than non-drinkers. We have examined the relationships between total alcohol intake and type of alcoholic beverage and several potential biological mechanisms.We carried out the study in 3158 men aged 60-79 years drawn from general practices in 24 British towns with no history of myocardial infarction, stroke or diabetes and who were not on warfarin. Total alcohol consumption showed a significant positive dose-response relationship with high density lipoprotein cholesterol (HDL-C), coagulation factor IX, haematocrit, blood viscosity, and tissue plasminogen (t-PA) antigen, and an inverse dose-response relationship with insulin, fibrinogen, von Willebrand factor (vWF) and triglycerides after adjustment for possible confounders. Total alcohol consumption showed weak associations with plasma viscosity and fibrin D-dimer, and no association with factors VII, VIII, or C-reactive protein (CRP). Wine was specifically associated with lower CRP, plasma viscosity, factor VIII and triglycerides.The findings are consistent with the suggestion that HDL-C in particular but also insulin and haemostatic factors may contribute to the beneficial effect of light to moderate drinking on risk of CHD.Wine has effects that may confer greater protection than other alcoholic beverages.
Increased leukocyte-platelet adhesion in patients with graft occlusion after peripheral vascular surgery
Authors: Esposito Claire , Popescu Wanda , Rinder Henry , Schwartz Jeffrey , Smith Brian , Rinder Christine 
Published: October 2003

SummaryGraft occlusion following peripheral vascular surgery is attributable to some combination of acute thrombosis, and progression of atherosclerosis: interactions between leukocytes and activated platelets may play a role in both of these processes. This investigation measured perioperative leukocyte-platelet conjugate formation, and leukocyte and platelet activation in 46 patients undergoing surgery for lower extremity peripheral vascular disease (PVD). All patients were followed for graft patency over the next 6 months; 27 patients had grafts that remained patent while 19 had graft occlusion. On postoperative day #1 (POD#1), the graft occlusion group demonstrated a significantly greater increase in circulating levels of both mono-cyteplatelet and neutrophil (PMN)-platelet conjugates compared to the patent graft patients (p=0.015 and 0.018, respectively). PMN activation, assessed by increases in surface CD11b expression, was also significantly increased on POD#1 in the graft occlusion group compared to the patent group (p=0.026). The percentage of circulating activated (CD62P+) platelets did not differ between groups, but patients with graft occlusion demonstrated a higher percentage of younger, reticulated platelets throughout the study period (p=0.008), indicating increased platelet turnover.We conclude that in the early postoperative period, leukocyte-platelet adhesion, PMN activation, and platelet turnover are significantly greater in PVD patients who go on to develop later graft occlusion. Cellular activation and heterotypic cell interactions in peripheral vascular surgery patients may be important in the etiologies of thrombosis and/or accelerated atherosclerosis leading to graft loss.
Blockade of GPIIb/IIIa by eptifibatide and tirofiban does not alter tissue factor induced thrombin generation in human endotoxemia
Authors: Derhaschnig Ulla , Pachinger Christine , Schweeger-Exeli Ingrid , Marsik Claudia , Jilma Bernd 
Published: October 2003

SummaryActivated platelets facilitate thrombin generation by providing a catalytic surface on which coagulation activation occurs. The glycoprotein (GP) IIb/IIIa receptor might play a major role in this process as shown by in vitro and animal experiments. However, it is controversial whether the GPIIb/IIIa receptor facilitates tissue factor-induced thrombin generation in humans as well. We therefore investigated whether two clinically used GPIIb/IIIa antagonists (tirofiban and eptifibatide) may blunt TF-induced coagulation in humans.Thirty male volunteers received 2 ng/kg endotoxin and standard doses of eptifibatide, tirofiban or placebo over 5 hours in a randomized, double-blind, placebo-controlled, double-dummy parallel-group trial. Markers of thrombin generation (prothrom-bin fragment 1+2, thrombin-antithrombin complexes), fibrinoly-sis (D-dimer, plasmin-antiplasmin complexes) as well as inflammatory markers (interleukin-6, tumor necrosis factor-α) were measured by enzyme linked immunoasssays, TF-mRNA expression was quantified by RT-PCR. Neither eptifibatide nor tirofiban influenced LPS-induced coagulation activation or fibrinolytic activity. Additionally, the increase of TNF-α and IL-6 was similar in all groups.In conclusion, GPIIb/IIIa blockade with eptifibatide or tirofiban did not influence TF-induced coagulation activation in human low grade endotoxemia.
Low protein Z plasma levels are independently associated with acute coronary syndromes
Authors: Fedi Sandra , Brogi Daria , Tellini Irene , Cesari Francesca , Sestini Ilaria , Gazzini Alessandra , Comeglio Marco , Abbate Rosanna , Franco Gensini Gian , Sofi Francesco 
Published: October 2003

SummaryProtein Z (PZ) is a single chain vitamin-K-dependent glycoprotein synthesized by the liver. Studies in vivo and in vitro suggest that PZ plays an important role in inhibiting coagulation as it serves as cofactor for the inactivation of factor Xa by forming a complex with the plasma PZ-dependent protease inhibitor. Recently, conflicting findings on plasma PZ levels in patients with ischemic stroke have been published.Aim of our study was to investigate the role of PZ in acute coronary syndromes (ACS). PZ plasma levels were determined in 223 (189 M; 34 F) patients with ACS referring to the Coronary Intensive Therapy Unit of University of Florence and in 265 (219 M; 46 F) healthy subjects. Patients under oral anticoagulation treatment as well as subjects with positivity for antiphospholipid antibodies were excluded. None had liver or kidney dysfunction. The mean PZ plasma level was lower in patients (1508 ± 730 ng/mL) than in controls (1728 ± 594 ng/mL) (p < 0.0001). PZ levels below the 5th percentile (565 ng/mL) of normal values distribution in control subjects were found in 15.7% of patients and in 4.9% of controls (p <0 .0001). At multivariate analysis, PZ levels below 565 ng/mL were associated with ACS (OR=3.3; 99%CI 1.1-9.7; p = 0.004). The contemporary presence of low PZ levels and smoking habit leads to an increased risk of ACS (OR=9.5; 99%CI 2.4-37.2; p < 0.0001). In conclusion, our results suggest a possible role of PZ in the occurrence of arterial thrombosis.
Blood coagulation and fibrinolysis before and after exhaustive exercise in patients with IDDM
Authors: Eichler Evelyn , Gläser Doreen , Prasa Dagmar , Stürzebecher Jörg , Gabriel Holger , Hilberg Thomas 
Published: October 2003

SummaryDiabetes mellitus involves changes in haemostasis which leads to the opinion that diabetes mellitus is a hypercoagulable state. However, little is known about the relationship of exercise and haemostasis in diabetics. Therefore, first of all the aim was to investigate if differences in blood coagulation and fibrinolysis can be demonstrated in subjects with insulin-dependent diabetes mellitus (IDDM) compared to controls and secondly, if differences concerning exercise induced changes can be seen in diabetics. 16 moderately fit subjects with IDDM and 16 matched controls underwent a maximal step test. Blood samples were taken after a 30 min rest, immediately and 1h after exercise and in addition after 30 min rest 7 days later at the same time of day. The rest values (mean of the two rest samples) in extrinsic total thrombin potential (TTPex, P=0.049), tPA-activity (P=0.007) were significantly higher and in PAI-1-antigen (P=0.002) -activity (P=0.049) lower in the diabetic group. APTT, PT, TAT (only control), TTPin, tPA-activity and -antigen and PAP were increased immediately and D-dimer (only control) 1 h after exercise, whereas PAI-1-activity and -antigen (only control) decreased immediately or 1 h after exercise (all minimal P<0.05). The increase of tPA-antigen and decrease in PAI-1-antigen after exercise were both lower in the diabetics (P<0.05).IDDM led to higher extrinsic total thrombin and fibrinolytic potential at rest, and reducing the exercise provoked distribution of tPA-antigen and decrease of PAI-1-antigen. Nevertheless a higher thrombotic risk after maximal exercise has not been investigated in young IDDM patients without complications and in good metabolic control.
Severe prekallikrein (Fletcher factor) deficiency due to a compound heterozygosis (383Trp stop codon and Cys529Tyr)
Authors: Teresa Sartori Maria , Cabrio Laura , Fadin Mariangela , Zanon Ezio , Girolami Antonio , Maria Lombardi Anna 
Published: October 2003

SummaryWe investigated a family with prekallikrein deficiency, using both standard coagulation tests and molecular biology techniques. The propositus was found to be a compound heterozygote for a Trp383 stop codon and a Cys529Tyr point mutation. The former mutation was located in exon 11, the latter in exon 14. The propositus inherited the first defect from his father and the second from his mother. Both parents had slightly low prekallikrein levels, but the combination of the two genetic defects produced a phenotype characterized by an extremely low prekallikrein activity and antigen. The propositus’ plasma showed a progressive reduction in APTT when incubated for a long time. Conversely, plasma deficient in factor XII, factor XI or high molecular weight kininogen (HMWK) failed to show shortening of the APTT. No circulating anticoagulant was found because the patient’s APTT was fully corrected by pooled normal and factor XII-, factor XI- or HMWK deficient plasma. No associated abnormality was apparent in the propositus or his parents. As expected, no tendency for bleeding was noted even after tonsillectomy.
A microsatellite polymorphism in the heme oxygenase-1 gene promoter is associated with increased bilirubin and HDL levels but not with coronary artery disease
Authors: Schillinger Martin , Marculescu Rodrig , Sunder-Plassmann Raute , Raith Marianne , Jordanova Nelli , Wojta Johann , Mannhalter Christine , Huber Kurt , Endler Georg , Exner Markus , Wagner Oswald 
Published: October 2003

SummaryHeme oxygenase 1 (HO-1) is involved in the generation of the endogenous anti-oxidant bilirubin which exerts beneficial effects against arteriosclerosis. A (GT) repeat polymorphism in the HO-1 promoter region modulates HO-1 expression in response to oxidative stress. Recently, this polymorphism has been reported to protect from coronary artery disease in Orientals. We intended to confirm this observation in Caucasians.We studied 649 individuals with myocardial infarction (n=258), stable coronary artery disease (n=180) and controls without coronary artery disease (n=211). Carriers of short alleles (<25 repeats) had higher bilirubin levels (median 0.66 mg/dL, IQR 0.49 to 0.91) compared to non-carriers (median 0.61mg/dL, IQR 0.45 to 0.82; p=0.03) and a more favourable lipid profile (HDL median 47mg/dL, IQR 40 to 50 vs. median 45, IQR 37 to 55, p=0.01; triglycerides median 118mg/dL, IQR 87 to 174 vs. median 132, IQR 97 to 191, p=0.03). However, no significant differences of the genotype distribution were observed between the three groups in this Caucasian study population (p=0.94).Although potentially beneficial effects of the short HO-1 allele on lipid profile and serum bilirubin were observed, in contrast to Orientals, the HO-1 genotype was not associated with coronary artery disease in Caucasians.