bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Fibrinolytic Stimulation by Stanozolol on Postoperative Pulmonary Complications
Authors: Cuschieri R.J. , Morran C.G. , Lowe G.D.O. , Blarney S.L. , Forbes C.D. , McArdle C.S.
Published: April 2009

Platelet aggregation in the lungs is common following abdominal surgery and may contribute to postoperative hypoxaemia. The hypothesis that an anabolic steroid, stanozolol, by preventing fibrinolytic shutdown, would prevent postoperative hypoxaemia was tested. Fifty patients undergoing abdominal surgery were randomly allocated to receive either placebo or stanozolol. Despite preventing fibrinolytic shutdown in most patients, the use of stanozolol did not influence the extent of postoperative hypoxaemia or the incidence of postoperative pulmonary complications. These results suggest that fibrinolysis does not play a significant part in the pathogenesis of postoperative pulmonary dysfunction.
Antithrombin III (AT III) and Fibrinogen Levels in Nephrotic Syndrome in Children
Authors: Elidrissy A.T.H. , Gader A.M.A.
Published: April 2009

Plasma antithrombin III (AT III) and fibrinogen were measured in 25 Saudi children with nephrotic syndrome during both relapse and remission. During relapse the mean AT III level was 46.6% (range 7–84%) and mean fibrinogen was 992 mg/dl (range 413–1,433), while during remission, AT III levels increased remarkably to a mean value of 120.6% (range 81–160) and plasma fibrinogen dropped to a mean level of 431 mg/dl (range 230–693). In 10 of these patients AT III was measured simultaneously in urine. During relapse urine AT III levels were of the same magnitude as plasma AT III, while during remission no AT III was detected in urine. These findings confirm the hypercoagulable state during the relapse of nephrotic syndrome and the quick recovery during remission. None of our patients showed any clinical evidence of thromboembolism. Loss of AT III in urine during relapse and/or its consumption is the probable cause of low AT III during relapse while excessive production of AT III by liver probably accounts for the high levels in remission.
Deep Vein Thrombosis and Related Platelet Changes after Total Hip Replacement
Authors: Paramo J.A. , Rocha E.
Published: April 2009

Postoperative changes related to platelets and their correlation with the incidence of deep venous thrombosis (DVT) were studied in 30 patients undergoing total hip replacement. Levels of platelet count, platelet-crit, mean platelet volume, spontaneous platelet aggregation, platelet factor 4 (PF4) and β-thromboglobulin (β-TG) were measured before operation and on the 1st, 3rd and 7th postoperative days. DVT was detected by 125I-fibrinogen leg scanning in 11 of the patients. After the operation there was a significant and progressive increase (p < 0.01) in PF4 and-TG, and the presence of circulating platelet aggregates was demonstrated. Platelet count levels and platelet-crit were decreased on the 1 st and 3rd postoperative days followed by recovery on the 7th day. The changes observed following total hip replacement were not related to the development of postoperative DVT.
Development of a Computer Program to Analyze the Parameters of Platelet-Vessel Wall Interaction
Authors: Escolar G. , Bastida E. , Castillo R. , Ordinas A.
Published: April 2009

The use of the Baumgartner perfusion system allows the morphometric quantification of platelets interacting with vessel wall, however it presents the basic difficulties of morphometrical measurements. In order to facilitate the procedure of evaluation we developed a semiautomated method to avoid the complexity of the classical evaluation. Our system consists on an optical picture analysis system connected with a specially developed computer program which allows fast quantification. Simultaneously to the outlining of interacting platelets the computer program recognizes, corrects, selects and stores the information, in order to perform the final calculations as previously established. This system has been demonstrated to be as effective as the classical morphometric evaluation in the measure of platelets interacting with subendothelium. Potential sources of error such as subjectivity of the observers in selecting the class of interacting platelets are avoided. The use of this combined method opens the possibility to adapt the Baumgartner perfusion system to clinical routine and to the screening of drugs that modify platelet adherence.
Endothelial Stimulation by DDAVP in von Willebrand’s Disease and Haemophilia
Authors: Greer I.A. , McLaren M. , Belch J.J.F. , Lowe G.D.O. , Forbes C.D.
Published: April 2009

Desamino-D-arginine vasopressin (DDAVP) is known to stimulate factor VIII (FVIII) and plasminogen activator release from endothelial cells, and has been shown to stimulate prostacyclin (PGI2) production in normal and haemophilic subjects. In von Willebrand’s disease (vWd) some patients have a dissociate response with regard to FVIII and plasminogen activator. The aim of our study was to compare the PGI2, FVIII and plasminogen activator response to DDAVP infusion in vWd with the response to DDAVP in normal and haemophilic subjects. PGI2 metabolites thromboxane B2 (TxB2), factor VIII coagulant activity, factor VIII-related antigen and plasminogen activator were measured before and after DDAVP infusion. There was a significant increase in PGI2 metabolites, factor VIII-related antigen and plasminogen activator in all groups following DDAVP, but no effect on TxB2 was found, and there was no evidence of any dissociate response to DDAVP in any of the groups. Basal levels of PGI2 metabolites, however, were significantly lower in vWd as compared to normal and haemophilic subjects. Post-DDAVP levels of PGI2 metabolites were also significantly lower in vWd as compared with normal subjects. This may be due to a reduced stimulus to PGI2 production in vWd secondary to defective platelet adhesion.
Platelet Function in Hypercholesterolemics before and after Hypolipidemic Drug Therapy
Authors: Zucker M.L. , Trowbńdge C. , Krehbiel P. , Jackson B. , Chernoff S.B. , Dujovne C.A.
Published: April 2009

Platelet function parameters were studied in type II hyperlipoproteinemics in relation to baseline and drug-induced changes in serum cholesterol levels. There were no significant differences between 28 type II hyperlipoproteinemics and 19 normal subjects in baseline values for platelet aggregation, thromboxane generation, sensitivity to prostacyclin, plasma platelet factor 4 or β-thromboglobulin. Eleven of the hyperlipoproteinemic patients were treated with a combination of the cholesterol-lowering drugs probucol and colestipol. The drug treatment resulted in statistically significant lowering of serum total and low-density lipoprotein (LDL)-cholesterol levels (30% reduction of mean LDL-cholesterol, p < 0.01); however, there was no significant change in any of the platelet function parameters after the drug treatment compared with placebo. These results provide evidence against a relationship between serum cholesterol levels and in vitro platelet function.
Partial Reversal of Low Molecular Weight Heparin (PK 10169) Anti-Xa Activity by Protamine Sulfate: In vitro and in vivo Study during Cardiac Surgery with Extracorporeal Circulation
Authors: Massonnet-Castel S. , Pelissier E. , Bara L. , Terrier E. , Abry B. , Guibourt P. , Swanson J. , Jaulmes B. , Carpentier A. , Samama M.
Published: April 2009

Neutralization of a low molecular weight (LMW) heparin fraction by protamine sulfate was evaluated in vitro and in vivo. Anti-Xa and anti-IIa activities were measured by amidolytic and coagulation methods (activated partial thromboplastin time, APTT). Fifteen patients (4 males and 11 females) underwent surgery with extracorporeal circulation. In vitro, anti-Xa and anti-IIa activities and APTT of unfractionated heparin were neutralized with a protamine/heparin (P/H) gravimetric ratio of 1.6, 1.33 and about 2, respectively. Anti-IIa activity and APTT induced by PK 10169 were completely corrected at a P/H ratio of 1 and 2, respectively, while anti-Xa activity was incompletely neutralized at a ratio of 5. In vivo, in 9 patients who did not receive intravenous protamine sulfate, a good correlation was found between doses of PK 10169 infused, anti-IIa plasma level and blood loss. In 3 patients who were treated prophylactically with protamine, bleeding was normal or only slightly increased. In 3 patients who received protamine because of hemorrhage, mean anti-Xa and anti-IIa were 2.3 and 0.54 U before and 1.32–0.06 U after neutralization. Bleeding was stopped by a second dose of protamine in 1 patient, but blood loss was abnormal in the other patients. However, a correlation between bleeding and anti-Xa or anti-IIa activities was not clearly evident.
Heparin-induced Thrombocytopenia
Authors: Kelton John G.
Published: April 2009

Heparin-induced thrombocytopenia is the most frequent and the most important idiosyncratic haematological drug reaction. It is important for several reasons: first, because heparin is used so often, and the frequency of heparin-induced thrombocytopenia is high, the risk of a hospitalized patient developing heparin-induced thrombocytopenia is high. Second, heparin-induced thrombocytopenia poses a major therapeutic dilemma for the clinician -continue the heparin and risk a worsening of the thrombocytopenia, or stop the heparin and risk extension or embolism of the thrombus. Finally, a small subset of patients with heparin-induced thrombocytopenia develop the disastrous complication of heparin-induced thrombocytopenia plus arterial thrombosis. Some of these patients die. In this review, we will summarize some of the issues concerning heparin-induced thrombocytopenia, including its frequency, the various techniques used to diagnose the condition, its pathophysiology and approaches that can be used to manage patients with heparin-induced thrombocytopenia.
Comparison between Hepatic and Nonhepatic Vitamin K-Dependent Carboxylase
Authors: Vermeer C.
Published: April 2009

Vitamin K-dependent carboxylase is a microsomal enzyme system involved in the carboxylation of protein-bound glutamic acid residues. In mammals, the enzyme is found in many different types of tissue. Hence carboxylated (‘Gla-containing’) proteins are widely distributed in nature. Neither in vitro nor in vivo differences have been observed with respect to the vitamin K-binding sites of the various carboxylases. Differences between the substrate-binding sites could only be compared after suitable substrates became available. These substrates were prepared from descarboxyprothrombin, osteocalcin and a sperm Gla protein. Substantial differences were detected between the Michaelis constants of various carboxylases for the three substrates mentioned above. It is concluded that vitamin K-dependent carboxylase is a group name for a family of isoenzymes.
Vitamin K-Dependent Procoagulant in Cancer Cells: A Potential Target for the Antimetastatic Effect of Warfarin?
Authors: Donati Maria Benedetta , Roncaglioni Maria Carla , Falanga Anna , Casali Bruno , Semeraro Nicola
Published: April 2009

Anticoagulants of the coumarin type have long been reported to inhibit metastasis growth in experimental animals; however, the mechanisms of such effects has not been clarified. Systemic anticoagulation per se does not appear to account completely for such metastasis growth depression. More recent information gathered on a cell procoagulant activity, which is vitamin K-dependent, could probably supply a fresh insight into this problem. Indeed, vitamin K deficiency induced either dietarily or pharmacologically by warfarin, does inhibit the activity of a cysteine protease with direct factor-X-activating properties. This protease is only present in warfarin-sensitive tumors. The correlation of this activity with cancer cell invasiveness is supported by experimental data in metastatic variants and, lately, also by the observation of markedly higher cancer procoagulant activity in extracts from metastases than from primary human melanomas.
Sub-Ambient Aggregometry: A Tool for Examining Platelet Storage at any Temperature between 4–22 °C
Authors: Trenchard P.M. , Morgan R.A.
Published: April 2009

A specifically modified commercially available aggregometer, referred to as a sub-ambient aggregometer, was used to measure certain parameters of platelet function throughout the temperature range of 4–37 °C. Platelet aggregation responses to ADP and stirring (spontaneous aggregation) were found to be maximal at room temperature. The possible relevance of this to routine platelet storage is discussed. Shear-induced light transmission change (SILTC) as a quick, repeatable, non-invasive index of platelet morphology was used to monitor small-sample platelet storage at 4 °C and during its subsequent resuscitation at 37 °C. This confirmed the combined usefulness of the sub-ambient aggregometer and SILTC measurements for monitoring platelets during storage. Further application of this approach should enable the optimum temperature for the liquid storage of platelets to be defined, which may not necessarily be 22 °C as usually employed.
Effect of Insulin Therapy on Coagulation and Platelet Function in Type II (Non-Insulin-Dependent) Diabetes mellitus
Authors: Small M. , Douglas J.T. , Lowe G.D.O. , MacCuish A.C. , Forbes C.D.
Published: April 2009

Twenty type II (non-insulin-dependent) poorly controlled diabetics had tests of coagulation and platelet function performed while receiving high-dose sulphonylurea therapy and at 1 and 3 months following their conversion to insulin. Although no overall change in glycaemic control (assessed by glycosylated haemoglobin) was noted, a reduction in thrombin generation was observed, as judged by a significant fall in fibrinopeptide A concentrations. No changes in factor VIII coagulant activity (VIII:C), factor VIII-related antigen or antithrombin III were found. Glycosylated haemoglobin concentrations showed significant correlations with antithrombin III and factor VIII:C, suggesting that improved glycaemic control might lead to an improvement of antithrombin III function and lower factor VIIl·C concentrations. No changes in platelet function were detected. The introduction of an insulin regimen that improves glycaemic control might lead to a reversal of the ‘hypercoagulable state’ found in type II diabetes.
Apolipoprotein B and Platelet Function in Diabetes mellitus
Authors: Kubisz P. , Pařizek M. , Cronberg S.
Published: April 2009

Serum levels of apolipoprotein B were measured, and investigations of the platelet function were carried out in 32 patients with insulin-dependent dabetes and in 34 healthy controls similar in age. Mean serum levels of apolipoprotein B were 1.51 g/l in the diabetic patients and 1.18 g/l in the control group, and this difference was significant. In the diabetic patients a secondary wave of aggregation was more easily induced by low concentrations of adenosine diphosphate or adrenaline. It was also possible to induce 50% of maximal aggregation by lower concentrations of adenosine diphosphate or arachidonic acid in these patients, and their number of circulating platelet aggregates increased. Plasma levels of β-thromboglobulin and platelet factor 4 were raised and, in the presence of N-ethyl maleimide, platelets from diabetic patients produced significantly more malondialdehyde than those from normal controls. The relationship between increased serum levels of apolipoprotein B and platelet hyperreactivity may be more than accidental and should be studied further to elucidate its possible implication with platelet function and atherogenesis.
Basement Membrane Components (7S Collagen, Laminin PI) Are Increased in Sera of Diabetics and Activate Platelets in vitro
Authors: Högemann B. , Balleisen L. , Rauterberg J. , Voss B. , Gerlach U.
Published: April 2009

Serum concentrations of two basement membrane components (7S collagen and laminin P1) were detected by specific radioimmunoassays in 70 patients suffering from diabetes mellitus type I and II with and without clinical signs of microangiopathy. Serum levels of both antigens were increased compared to controls. 7S collagen concentrations were significantly different between the diabetics with signs of microvascular damage and those without small-vessel disease (p < 0.05). Laminin P1 concentrations were also elevated, but the difference between the two groups of diabetics was not significant (p < 0.2). Raised levels of circulating basement membrane proteins may indicate connective tissue activity and development of diabetic microangiopathy. In vitro 7S collagen is a moderate platelet activator inducing platelet spreading, aggregation, and malondialdehyde production. Laminin activates platelet spreading. As a part of the altered hemostatic system the activation of basement membrane components may contribute to the development of microvascular damage.
Nonenzymatic Glucosylation as a Contributing Factor to Defective Fibrinolysis in Diabetes mellitus
Authors: Geiger M. , Binder B.R.
Published: April 2009

Kinetics of activation of plasminogen purified from the plasma of 3 uncontrolled diabetic patients by tissue type plasminogen activator revealed substrate inhibition in the fibrin-stimulated system. After improvement of metabolic parameters activation of plasminogen was found to be normal in 1 of these patients and partially improved in another patient. Studies performed to investigate a possible nonenzymatic glucosylation of plasminogen showed that purified control plasminogen incorporates 14C-glucose in a dose- and time-dependent manner and that in vitro glucosylation of control plasminogen results in functional abnormalities of plasminogen, which resemble those observed with plasminogen from diabetic patients as far as substrate inhibition in the fibrin-stimulated system is concerned.
Heparin Preserves Antithrombin III Biological Activity from Hyperglycemia-Induced Alterations in Insulin-Dependent Diabetics
Authors: Ceriello Antonio , Giugliano Dario , Quatraro Antonio , Stante Aldo , Consoli Giuseppe , Russo Patrizia Dello , D’Onofrio Felice
Published: April 2009

Alteration in antithrombin III (ATIII) biological activity, despite its normal plasma concentration, in diabetic subjects is shown in this report. This alteration is glycemia level-dependent, there existing an inverse correlation between fluctuations of daily blood glucose level, labile glycosylated hemoglobin and ATIII activity. The Subcutaneous and endovenous heparin administration restores ATIII activity, but does not modify its plasma concentration in diabetics. Moreover, heparin treatment preserves ATIII activity from glycemia-induced alterations. These data suggest a role for glucose, probably through a labile nonenzymatic glycation process, in determining the alteration of ATIII biological activity. Moreover, showing the possibility by heparin administration to restore ATIII activity and preserve its biological function from effects of glycemia variations, stress the hypothesis that glucose and heparin compete in vivo, both against the same catalytic residue of ATIII.
Effect of Defibrotide in Electrically Induced Thrombosis in Dogs
Authors: Ulutin O.N. , Tunali H. , Uǧ;ur M.Ş. , Aytiş Ş. , Erbengi T. , Balkuv-Ulutin Ş.
Published: April 2009

Thrombi were electrically induced in dogs. The alterations of the vessel wall were studied in samples obtained on the 8th day from control and treated animals. Changes in coagulation parameters were monitored daily. Animals were treated with 600 mg defibrotide (Crinos) daily for a week, starting 24 h after the induction of thrombi. In the control dogs there was thickening of intima with endothelial hyperplasia and smooth muscle proliferation. The treated animals did not show any morphological or ultrastructural alterations (SEM). This observation encourages us to examine the role of fibrinolytic and endothelial supportive therapy for prevention of development of vascular changes.
Effects of Defibrotide on Peripheral Obliterative Vascular Diseases
Authors: Ulutin O.N. , İlhan-Berkel N. , Tunali H. , Özer M. , Balkuv-Ulutin Ş. , Önsel Ç. , Urgancioǧ;lu I.
Published: April 2009

Twenty-nine patients with atherosclerotic obliterative vascular disorder and 9 cases of Buerger’s disease were treated with 600 mg defibrotide daily for 10 days and then three times weekly for 3 months. The response to therapy was evaluated from hemostatic parameters, venostasis test (cuff test), treadmill testing, and radionuclide arteriography. We observed increased pain-free intervals in daily life and during treadmill testing. There was also a significantly higher response in the cuff test and improved perfusion as seen by radionuclide arteriography.
Subcutaneous Heparin Treatment of Deep Venous Thrombosis: A Comparison of Unfractionated and Low Molecular Weight Heparin
Authors: Holm H.A. , Ly B. , Handeland G.F. , Abildgaard U. , Arnesen K.E. , Gottschalk P. , Høeg V. , Aandahl M. , Haugen K. , Lœrum F. , Scheel B. , Sortland O. , Vinje B.
Published: April 2009

In a double-blind study, patients with phlebographically proven deep venous thrombosis (DVT) were treated with subcutanous injections twice a day of either unfractionated heparin (UH; n = 27) or low molecular weight heparin (LH; n = 29) for 7 days, and the dose was adjusted until therapeutic range was reached, according to a chromogenic substrate anti-Xa assay. Forty-eight percent of the LH group did not need dose adjustment as compared to 24% of the UH group. During the course of heparin administration, deviation from initial heparin activity was frequent in both groups, but mean activity did not indicate a cumulative effect in either group. There was 1 incidence of pulmonary embolism (LH) and only 1 minor bleeding episode (UH). Half of the patients in both groups were phlebographically improved. We conclude that subcutaneous heparin treatment with UH or LH appears safe and convenient.
Synthesis of Thromboplastin (Tissue Factor) by Endothelial Cells
Authors: Prydz H. , Pettersen K.S.
Published: April 2009

Molecular genetics, biochemistry, and cell biology of thromboplastin are briefly reviewed with special emphasis on its biosynthesis by endothelial cells.
Interaction of Blood Platelets with the Vessel Wall
Authors: Nievelstein Patricia F.E.M. , de Groot Philip G.
Published: April 2009

This review summarizes current insights in the importance of endothelium in the interaction of platelets with the subendothelium. A greater part of the results described are obtained with the use of cultured vessel wall cells. The following subjects are discussed: (1) the pro- and antithrombotic properties of the endothelial cells; (2) the synthesis of subendothelium by the endothelial cells and the influence of the composition of the subendothelium on its reactivity towards blood platelets; (3) the effect of (purified) matrix and plasma proteins on the adhesion process, and (4) various abnormalities of platelet adhesion are discussed that lead to enhanced bleeding tendency or to increased thrombus formation.
Coagulation Factor VII and Plasma Triglycerides
Authors: Carvalho de Sousa J. , Bruckert E. , Giral P. , Soria C. , Chapman J. , Truffert J. , Dairou F. , De Gennes J.L. , Caen J.P.
Published: April 2009

High circulating levels of coagulation factor VII (FVII) are known to be associated with elevated concentrations of blood lipids. More specifically, hypertriglyceridemia is correlated with raised FVII coagulant activity (FVIIc). Recently, evidence has been described which suggests that elevation in FVIIc might reflect an increase in the total concentration of FVII, as evaluated by quantitation of FVII antigen (FVIIag). It is also known that FVIIc represents a risk factor for cardiovascular death, but the prediction of cardiovascular risk based on triglyceride estimation is the subject of conflicting results. Since dyslipidemia featuring abnormal triglyceride metabolism is pathophysiologically heterogeneous, we analyzed the possible relationships between FVII and triglyceride further and under standardized postprandial conditions. For this purpose we studied FVIIc and FVIIag in relation to triglyceridemia after a standardized test meal. Our results confirm that FVIIc and FVIIag levels are strongly correlated with each other (r = 0.714; p = 0.01). In addition, both were significantly increased (p < 0.02) in patients who exhibited abnormal triglyceride levels 8 h after a standardized test meal, as compared to those who displayed normal triglyceridemia. Furthermore, we found that apolipoprotein B levels were also increased in such patients. The deficient postprandial catabolism of triglycerides, therefore, appears to be related to an increase in total FVII concentration, suggesting that some association between the metabolism of triglyceride-rich lipoproteins and FVII might underlie the mechanism of the elevation in FVII. Given the important contribution of FVII to hypercoagulability, then our results may be relevant to the understanding of the role of postprandial triglyceride in atherogenesis and in consideration of the circadian prevalence of cardiovascular thrombosis.
Assay Discrepancies with Highly Purified Factor VIII Concentrates
Authors: Dawson N.J. , Kemball-Cook G. , Barrowcliffe T.W.
Published: April 2009

We have assayed two different monoclonal-antibody-purified concentrates (A and B) and one conventional concentrate (C), against the 3rd International Standard for factor VIII concentrate, using one-stage, two-stage and chromogenic methods. One-stage assays performed with immunodepleted plasmas gave lower potencies than with haemophilic plasma for all concentrates, though the discrepancies were most marked for the two highly purified products. The absence of von Willebrand factor in one of the immunodepleted plasmas appeared to contribute towards the low potencies observed. In addition, potencies of product A were 50% higher by one-stage assays (haemophilic plasma) than by two-stage or chromogenic methods. These results indicate the need for careful evaluation of assay methodologies for assessment of factor VIII:C activity in highly purified concentrates.
Variations of Prothrombin Time, Factor VII and Protein C with a Single Daily Dose of Acenocoumarol
Authors: Fiessinger J.N. , Vitoux J.F. , Roncato M. , Dellinger A. , Dizien O. , Aiach M.
Published: April 2009

In 11 patients on steady anticoagulation with a daily dose of acenocoumarol, prothrombin time, factor VII and protein C were measured 2 and 16 h after the daily intake of acenoumarol. Prothrombin time (expressed as International Normalised Ratio) increases significantly, factor VII and protein C decrease between the two samples. These results suggest that a daily dose of acenoumarol is associated with fluctuation of the anticoagulant effect.
Fibrinopeptide A Levels in Patients with Acute Ischaemic Heart Disease
Authors: Pacchiarini L. , Storti C. , Zucchella M. , Salerno J.A. , Grignani G. , Fratino P.
Published: April 2009

Fibrinopeptide A (FPA) levels were determined in 40 consecutive patients admitted to the coronary care unit with a typical history of chest pain: in 24 of them a diagnosis of acute myocardial infarction (AMI) and in 16 a diagnosis of angina was made. Seven of the patients with AMI suffered from recurrent episodes of early post-infarctional angina. FPA levels were determined in each patient on admission and every 4 h for 48 h. On admission in patients with both angina and AMI the FPA levels were significantly higher than in normal controls; these levels were higher in patients with AMI than in those with angina, but this difference was not significant. In patients with angina the values decreased progressively after 12 h to baseline values, while in those with AMI the high levels of FPA persisted throughout the 48-hour observation period. In many instances, particularly after 24 h, the differences between the two groups were statistically significant. In patients with early post-infarctional angina the episode of angor was preceded by or corresponded to a new great elevation of FPA levels. These data suggest that the thrombin generation is higher and more prolonged in patients with AMI than in those with angina; the determination of FPA levels, which are an index of ‘in vivo’ thrombin generation, can be useful to follow the clinical course of ischaemic heart disease.
A Sensitive in vivo Platelet Function Test in Rats Based on Intravenously Injected Collagenase
Authors: Völkl K.-P.
Published: April 2009

The transient decrease of the platelet concentration in the flowing blood after intravenous injection of collagenase was used as a measure for the effectiveness of the platelet-vessel wall interactions in rats. The decrease of the concentration in circulating platelets was regarded as an expression of the in vivo platelet function. The influence of acetylsalicylic acid, imidazole, indomethacin, ketanserin, RA 233, and dipyridamole on this test was investigated in anaesthetized rats. All tested drugs showed an effect on the extent of the platelet concentration decrease after the collagenase injection compared to the control values, but no drug was significantly effective. This test could prove to be a valuable tool for testing the efficiency of antithrombotic drugs in vivo.
Induced Antibodies to von Willebrand Factor
Authors: Hessel Birgit , Johnsson Hans , Silveira Angela
Published: April 2009

Plasma from 15 patients with haemophilia A and 4 patients with von Willebrand’s disease (VWD) has been investigated for the presence of antibodies to von Willebrand factor (VWF) using ELISA and immunoblotting systems. All plasma samples were also analyzed for anticoagulant activity against factor VIII coagulant activity (FVIIl·C) and ristocetin co-factor activity of VWF (RCof). The patients were on regualr prophylaxis or treated ‘on demand’ with different commerical FVIII-VWF complex concentrates. Neutralizing activity against FVIIl·C was only found in haemophiliacs (in 3 out of 15), whereas anti-RCof was only found in VWD patients (in 2 out of 4). In ELISA, antibodies to VWF were detected in 3 of the VWD patients. However, using the immunoblotting system, antibodies to the multimeric structure of VWF were found not only in VWD patients (in 3 out of 4); remarkably 9 out of 15 haemophiliacs also reacted with VWF, including some that did not show FVIIl·C inhibitors. The pattern of VWF multimers obtained with the antibodies showed differences among the patients. These findings are discussed together with the mechanisms by which such antibodies could have developed in haemophilia A patients who are not deficient in this particular protein (VWF).
Clinical Experience with Human Plasma-Derived Factor VIla in Patients with Hemophilia A and High Titer Inhibitors
Authors: Hedner U. , Bjoern S. , Bernvil S.S. , Tengborn L. , Stigendahl L.
Published: April 2009

FVIIa purified from human plasma and spontaneously activated during the purification procedure was given to 4 patients with hemophilia A and inhibitors against FVIIl:C in association with joint bleeds. A dose of 9–20 μg/kg b.w. (700–1,000 U/kg b.w.) seemed to be hemostatically active in moderate to severe joint bleeds. Plasma levels of FVΠ of 5–7 U/ml were achieved and recoveries varied between 17 and 66%. The lower recovery rates of 17–39% were all found in 1 of the patients. No immediate side effects were seen. Neither were any signs of a systemic activation of the coagulation system observed. It is concluded that highly purified FVIIa may be useful in the treatment of hemophilia A patients with inhibitors against FVIII:C.
Vitamin K1 Levels and Coagulation Factors in Healthy Term Newborns till 4 Weeks after Birth
Authors: Pietersma-de Bruyn A.L.J.M.P. , van Haard P.M.M. , Beunis M.H. , Hamulyák° K. , Kuijpers J.C.
Published: April 2009

Vitamin K1 serum levels were assessed by means of an off-line multidimensional liquid chromatography in 18 mothers, shortly after delivery, and in their healthy term infants. Umbilical cord and venous blood samples were assayed up to 4 weeks of life. Concurrently, levels of coagulation factors II and X, antithrombin III and platelets were established. Although the detection limit of the assay was as low as 22 pg/ml, vitamin K1 concentration appeared to be still beyond that level in cord blood or in newborn serum within 30 min after birth, whereas vitamin-K-dependent coagulation factors are already at a level of 40 %, without evidence for the presence of descarboxy prothrombin, in any of the investigated neonates. After 3 days, breast-fed neonates had lower vitamin K1 levels than formula-fed infants (0.76 and 1.44 ng/ml, respectively). The levels of the vitamin-K-dependent coagulation factors II and X, however, were comparable, regardless of the kind of feeding. After 28 days, breast-fed neonates had even lower vitamin K1 levels (0.49 ng/ml, while the formula-fed infants showed higher vitamin K1 levels (4.45 ng/ml). But even then, the levels of vitamin-K-dependent coagulation factors II and X were comparable, regardless of the kind of feeding. From this we conclude that the serum levels of vitamin K1 in formula-fed neonates exceed those of breast-fed infants from the moment of feeding (24 h and later) without a concomitant rise in vitamin-K-dependent coagulation factors. A relationship between vitamin K1 levels and vitamin-K-dependent coagulation factors could not be established in healthy term breast-fed or formula-fed infants.
The Serotonergic Mechanisms Are Not Involved in the Inhibitory Effect of Captopril on Rat Platelet Aggregation
Authors: Malinowska B. , Chabielska E. , Pietraszek M.H. , Buczko W.
Published: April 2009

The influence of captopril on blood platelet aggregation and on serotonergic mechanisms in blood platelets were studied. In rats pretreated with captopril (10.0 mg/kg p.o.) platelet aggregation induced by ADP and collagen was significantly reduced. In vitro this drug had no inhibitory effect. Besides, captopril did not change the amplifying effect of serotonin on platelet aggregation. Captopril also had no influence on the uptake and storage of 5-hydroxytryptamine by rat blood platelets. These results show that serotonergic mechanisms are not involved in the suppressive effect of captopril on platelet aggregation.
Coagulation Disturbances in Cancer of the Breast and Colon Measured with Specific Monoclonal Antibody Enzyme Immunoassay for Fibrin-Fibrinogen Degradation Products
Authors: McCulloch P. , Nieuwenhuizen W. , Douglas J. , Lowe G.D.O. , George W.D.
Published: April 2009

Disturbances of coagulation were measured in breast cancer, colon cancer and benign breast disease using an enzyme immunoassay against total plasma fibrinogen and fibrin degradation products (TDP). Results were compared with measurements of fibrinopeptide A (FPA) and of serum fibrinogen-related antigen (FRA). Plasma TDP before surgery was significantly higher in colon cancer than in breast cancer patients (p = 0.0009) or in benign breast disease (p = 0.0292). A post-operative rise in TDP at 4 months (colon cancer) or 9 months (breast cancer) was associated with early recurrent disease (p < 0.0173 for colon cancer, p < 0.1835 for breast cancer). No such association was noted with FPA or FRA measurements. TDP may prove to be of value in detecting activation of coagulation by malignant disease.
In vitro Studies of the Effect of Buflomedil on Platelet Responsiveness
Authors: Ryckewaert Jean Jacques , Maurel Alain , Marguerie Gerard
Published: April 2009

The effect of buflomedil (Fonzylane®; Laboratoire Lafon, Maisons-Alfort, France) on platelet function, a drug used clinically for the treatment of peripheral vascular diseases, was investigated in vitro. The compound significantly inhibits epinephrine-induced aggregation at the micromolar level. At higher doses (approximately 1 mM), a weak inhibition of ADP- and collagen-induced aggregation was observed; at these concentrations, buflomedil inhibits granular secretion and the interaction of fibrinogen with its receptor on platelet. Further investigations indicate that the drug affects calcium uptake at the membrane level and inhibits the binding of [3H]-yohimbine to the same extent as observed with phentolamine. The IC50 determined from competition binding assays was 1 ± 0.5 μM. This value was consistent with the affinity constant approximated for the binding of [3H]-buflomedil to non-stimulated platelets. Taken together, these results indicate that the vasoactive compound buflomedil is a weak antiaggregating agent which exhibits α2-adrenergic antagonistic properties.
Human Monocytes Release Plasma Serine Protease Inhibitors in vitro
Authors: Kłoczko J. , Bielawiec M. , Giedrojć J. , Radziwon P. , Galar M.
Published: April 2009

The ability of human peripheral blood monocytes to secrete plasma serine protease inhibitors was studied. Monocytes from blood obtained from healthy young adult volunteers were cultured for up to 36 h with and without lipopolysaccharide from Escherichia coli. The concentrations of plasma serine protease inhibitors in monocyte culture supernatants were measured by using rocket immunoelectrophoresis. The study showed that human monocytes stimulated with lipopolysaccharide in vitro release antithrombin III, C1 esterase inhibitor, α2-antiplasmin, and α2-macroglobulin.
Low Molecular Weight Heparins: An Introduction
Authors: Coccheri Sergio
Published: April 2009

Heparin fractions and fragments are useful tools in the elucidation of the mechanism of action of heparin and similar substances. The identification of portions with low or high affinity for antithrombin III and of a ‘core’ pentasaccharide responsible for anti-factor Xa activity has been possible thanks to heparin fractionation and fragmentation procedures. The development of low molecular weight heparins led to the production of substances with a molecular weight around 5,000, considerably variable in chemical structure, anti-factor Xa and anti-factor IIa activities, and experimental antithrombotic effects. The original rationale according to which fragments with high anti-factor Xa activity and anti-factor Xa/anti-factor IIa ratio would retain optimal antithrombotic activity with greatly reduced prohemorragic actions, turned out to be an oversimplification of the problem. In fact, neither is the anti-factor Xa activity the only determinant of the antithrombotic effect, nor is the anti-factor IIa activity a good predictor of hemorrhage. Despite disaggregation of the original rationale, low molecular weight heparins have already proved to be at least as effective and safe, and more conveniently and practically administered, as unfractionated heparin in the prophylaxis of deep-vein thrombosis.
Role of Granulocytes in the Development of Venous Thrombosis in Patients with Hip Fractures
Authors: Monreal M. , Lafoz E. , Arias A. , Casals A.
Published: April 2009

In a previously reported study we compared the use of a low-molecular-weight heparin (LMWH) and conventional heparin in the thromboprophylaxis of patients with hip fracture. In an attempt to establish additional factors which could aid in predicting the development of deep-venous thrombosis (DVT), we retrospectively studied several clinical and laboratory variables and found that granulocyte count on admission was higher in patients without subsequent postoperative DVT. Forty additional patients were included in a further prospective study in order to validate our previous findings. 38% of patients who developed DVT had a granulocyte count lower than 9,500/μl, whereas only 18% of those patients with DVT had a count higher than 9,500/μl. These figures imply a positive predictive value of 38 % and a negative predictive value of 82%. We suggest that granulocytes could play a role in the development of DVT and preoperative granulocyte count may be used to detect a high-risk population for DVT after a hip fracture.
Determination of the Levels of Unfractionated and Low-Molecular-Weight Heparins in Plasma: Their Effect on Thrombin-Mediated Feedback Reactions in vivo
Authors: Hemker H.C. , Béguin S. , Bendetowicz A.V. , Wielders S.
Published: April 2009

We define a standard independent unit (SIU) of heparin as that amount that, in plasma containing 1 μmol of ATIII, raises the (pseudo-)first-order breakdown constant of factor Xa by 1 min-1• These units measure all material with a high affinity for ATIII (HAM); only material above the critical chain length of 17 monosaccharide units (above critical chain length material; ACLM) catalyzes the inactivation of thrombin. An SIU of ACLM is therefore analogously defined as the amount that, in plasma containing 1 μmol of ATIII, will raise the (pseudo-)first-order breakdown constant of thrombin by 1 min-1• Of any given heparin preparation one can determine the specific HAM and ACLM activities in terms of SlU/mg. On the basis of the factor Xa and thrombin breakdown constants found in a plasma sample one can then determine the levels of HAM and ACLM. Preliminary experiments were carried out in plasma samples obtained after subcutaneous injection of unfractionated heparin (UFH) and of two types of low-molecular-weight heparin (LMWH). About three times more of UFH activity than of LMWH activity has to be injected to obtain the same levels of ACLM in the plasma. Only with the LMWHs significant amounts of BCLM are found, which rises higher and persists longer than the ACLM. We determined the course of thrombin generation in platelet-rich plasma (PRP) and in platelet-poor plasma (PPP), as well as in the PPP factor Xa generation curve and the course of prothrombin conversion. The observed inhibitions correlated much better with the levels of ACLM than with those of below critical chain length material. The difference between UFH and LMWHs can therefore not be explained in terms of antithrombin and anti-factor-Xa activity. The essential difference between UFH and LMWH appears in the feedback effect of thrombin in PRP, where thrombin generation is both inhibited and retarded by LMWH, while it is only retarded but hardly inhibited by UFH.
Intramedullary Multiple Hematomas in Siblings with Congenital Alpha-2-Plasmin Inhibitor Deficiency: Orthopedic Surgery with Protection by Tranexamic Acid
Authors: Takahashi Y. , Tanaka T. , Nakajima N. , Yoshioka A. , Fukui H. , Miyauchi Y. , Mii Y. , Tamai S.
Published: April 2009

Congenital α2-plasmin inhibitor deficiency is very rare, but causes bleeding problems similar to hemophilia. Three young Japanese sisters affected with congenital α2-plasmin inhibitor deficiency have been reported by us earlier. Recently we encountered a particular form of intrameduUary multiple hematomas in the long bones in all of them which was not reported previously. In 2 of the sisters orthopedic operations were successfully performed by using an antiplasmin reagent: tranexamic acid. In this paper we describe the characteristics of the hematomas and the hemostatic management with tranexamic acid.
Some Objective Considerations for the Neutralization of the Anticoagulant Actions of Recombinant Hirudin
Authors: Fareed Jawed , Walenga Jeanine M. , Pifarre Roque , Hoppensteadt Debra , Koza Mike
Published: April 2009

Recombinant hirudin (r-hirudin) is currently under development as an anticoagulant for use in surgery, therapeutic anticoagulation, disseminated intravascular coagulation and other pathologic states involving the generation of thrombin. Circulating levels of r-hirudin as an antithrombotic agent range from 2 to 20 μg/ml (0.1–1.0 mg/kg) as determined in an animal model of stasis thrombosis. In order to establish a relationship between the r-hirudin circulating level and bleeding, we utilized a rabbit ear blood loss model. r-Hirudin did not produce any loss of blood at dosages up to 20 μg/ml i.v. (1.0 mg/kg). When the circulating levels were maintained at 20 μg/ml for periods of up to 3 h, no increase in blood loss was observed. At 50 and 100 μg/ml initial circulating levels (2.5 and 5.0 mg/kg) a dose-dependent increase in the blood loss was observed which was equivalent to that observed with 1.25 and 2.5 mg/kg i.v. heparin. Such levels of r-hirudin are not expected in clinical usage. In contrast to heparin, the anticoagulant actions of r-hirudin were not neutralized by protamine sulfate, platelet factor 4, other polycationic agents and heparinase. In our studies, the blood loss induced by > 2.0 mg/kg i.v. dosages of r-hirudin in an animal model was neutralized by the administration of an activated pro thrombin complex concentrate at 25 U/ kg. In a similar experimental setting, r-factor Vila was also partially effective. These studies suggest that r-hirudin anticoagulation may not require neutralization, since bleeding effects are not observed at effective antithrombotic dosages in individuals with normal hemostatic status. However, in individuals with a hemostatic deficit, r-hirudin may augment bleeding. In circumstances where excessive bleeding might occur, however, r-hirudin can be partially neutralized by activated prothrombin complex concentrates.
A Mutation in the β3 Subunit of the Cardiac Sodium Channel Associated With Brugada ECG Phenotype
Authors: Hu Dan , Barajas-Martinez Hector , Burashnikov Elena , Springer Michael , Wu Yuesheng , Varro Andras , Pfeiffer Ryan , Koopmann Tamara T. , Cordeiro Jonathan M. , Guerchicoff Alejandra , Pollevick Guido D. , Antzelevitch Charles
Published: April 2009

Background—Brugada syndrome, characterized by ST-segment elevation in the right precordial ECG leads and the development of life-threatening ventricular arrhythmias, has been associated with mutations in 6 different genes. We identify and characterize a mutation in a new gene.

Methods and Results—A 64-year-old white male displayed a type 1 ST-segment elevation in V1 and V2 during procainamide challenge. Polymerase chain reaction-based direct sequencing was performed using a candidate gene approach. A missense mutation (L10P) was detected in exon 1 ofSCN3B, the β3 subunit of the cardiac sodium channel, but not in any other gene known to be associated with Brugada syndrome or in 296 controls. Wild-type (WT) and mutant genes were expressed in TSA201 cells and studied using whole-cell patch-clamp techniques. Coexpression ofSCN5A/WT+SCN1B/WT+SCN3B/L10P resulted in an 82.6% decrease in peak sodium current density, accelerated inactivation, slowed reactivation, and a −9.6-mV shift of half-inactivation voltage compared withSCN5A/WT+SCN1B/WT+SCN3B/WT. Confocal microscopy revealed thatSCN5A/WT channels tagged with green fluorescent protein are localized to the cell surface when coexpressed with WTSCN1BandSCN3Bbut remain trapped in intracellular organelles when coexpressed withSCN1B/WT andSCN3B/L10P. Western blot analysis confirmed the presence of NaVβ3 in human ventricular myocardium.

Conclusions—Our results provide support for the hypothesis that mutations inSCN3Bcan lead to loss of transport and functional expression of the hNav1.5 protein, leading to reduction in sodium channel current and clinical manifestation of a Brugada phenotype.