bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Factors II, VII, IX, X, and Protein C in Hepatosplenic Schistosomiasis
Authors: Amin Hesham M. , Omran Sawsan A. , El-Bassuoni Nora E. , El-Kaliouby Amna H. , El-Ashmawy Salah A.
Published: May 2009

Forty-four patients with schistosomiasis mansoni were divided into two groups: a group of 31 patients with hepatosplenomegaly and a group of 13 patients with advanced hepatic fibrosis and ascites. Both groups were compared to a control group of 14 healthy subjects. Screening of the extrinsic and intrinsic coagulation pathways was performed by PT (%) and aPTT. Functional assays of vitamin-K-dependent coagulation proteins: factors II, VII, IX, X, and protein C were conducted by using standard methods. A progressive reduction in PT (%) and prolongation in aPTT were detected in the diseased groups. Furthermore, all studied coagulation proteins showed a progressive reduction in their activities, which became more pronounced in the group with advanced ascites. We conclude that the significant reduction in vitamin-K-dependent coagulation proteins might add to the coagulopathy and bleeding diathesis noted in patients infected with Schistosoma mansoni.
Coagulation/Fibrinolysis Balance in Septic Shock Related to Cytokines and Clinical State
Authors: Massignon D. , Lepape A. , Bienvenu J. , Barbier Y. , Boileau C. , Cœur P.
Published: May 2009

This study explored the relationship between cytokines (TNF, IL-1, IL-6), coagulation and fibrinolytic factors in the early stage of sepsis syndrome and the relation between these factors with the severity of inflammatory illness as measured by the Simplified Acute Physiology Score (SAPS). Twenty-one normal controls were compared to 34 patients divided into three categories ranging from uncomplicated postoperative patients, to patients with severe infectious conditions including septic shock. A major hemostatic imbalance was demonstrated with particularly marked reduction in fibrinolytic activity [drop of antithrombin III (ATIII) and protein C with an increase of plasminogen activator inhibitor (PAI-1) levels] which were directly correlated with the severity of the inflammatory state. Both ATIII and PAI-1 levels were correlated with the levels of TNF and IL-6 and the severity of illness as measured by SAPS. We established an index, ATIII/PAI-1 antigen that is significantly different among the four groups (p < 0.001) and strongly correlated with the SAPS (p < 0.001). As PAI-1 could be secreted not only by TNF activating endo-thelial cells but also by hepatocytes activated by insulinemia, treatment of sepsis with cytokine-specific agents might be of limited effect.
A Prospective Epidemiological Study on the Occurrence of Antiphospholipid Antibody: The Montpellier Antiphospholipid (MAP) Study
Authors: Schved J.F. , Dupuy-Fons C. , Biron C. , Quéré I. , Janbon C.
Published: May 2009

The objective of this study was to determine the prevalence and clinical significance of elevated antiphospholipid antibodies (APA) in a large series of patients admitted to a departament of Internal Medicine. At the end of entry phase, 1014 patients were tested (488 males-526 females, mean age: 66,7 years, range 18-97). Seventy-two (7.1 %) patients were found APA positive at least once: 44 males and 28 females, mean age 69 years, range 23 to 94. Twenty fulfilled the criteria of Primary Antiphospholipid Antibody Syndrome: 10 patients were referred for deep vein thrombosis, 3 had history of deep vein thrombosis, 1 had both arterial thrombosis and a history of venous thrombosis; 2 had thrombocytopenia; 3 had stroke, 1 had a history of s troke. One patient had SLE according to ARA classification. The most frequent associated disease was cancer: 14 patients, 9 had evolutive malignant disease, 5 were in clinical remission of neoplasia. Other clinical conditions included chronic and/or acute alcoholic intoxication (n=8), severe atherosclerosis (n=4), leg ulcer (n=4). Insufficient data are available about the evolution, but 7 patients died in the year following diagnosis. Eight patients had fluctuations in APA detection: 2 initially APA positive became negative, 5 initially negative became positive and 1 patient was alternatively positive, negative and positive without steroid treatment. Thus, as expected, APA occur in a variety of clinical disorders. The association with cancer or alcoholic intoxication deserves further investigations.
Experimental Models for Antiphospholipid Studies
Authors: Gharavi A.E. , Aron A.L.
Published: May 2009

Three types of Experimental Animal Models have been used to investigate APA. 1) Passive transfer of APA to nocive mice. Branch et al injected pregnant Balb/c mice with purified IgG APA from patients with recurrent fetal loss. 2) Active immunization with APA. Backimer et al immunized Balb/c mice with a human monoclonal APA carrying the pathogenic idiotypes. 3) Immunization with β2 glycoprotein I (β2 GPI) (APA cofactor).Using affinity chromatography, we separated two distinct populations of antibodies. One was specific for β2GPI without binding to PL. Another population had a dual specificity for PL and β2GPI.
Low Doses of Endotoxin Potentiate Venous Thrombosis in the Rabbit
Authors: Bernat A. , Sainte-Marie M. , Roque C. , Ingelaere V. , Maffrand J.P. , Herbert J.M.
Published: May 2009

Procoagulant activity of the endothelium and of monocytes was induced by an intravenous administration of a low dose of endotoxin in the rabbit. Venous thrombosis induced by a 45-min stasis of the jugular vein was dramatically increased after the administration of endotoxin. Endotoxin enhanced venous thrombosis in a dose-dependent manner which was the highest after the administration of 1 µg/kg. This effect increased with time but was optimal when endotoxin was injected 4 h before stasis induction. Leukocytes appear to play a key role in this process since mechlorethamine-induced leukopenia totally inhibited thrombus formation. Hirudin and heparin, administered intravenously 5 min before stasis, were both potent inhibitors of endotoxin-induced venous thrombosis exhibiting ED50 values of 3.8 ± 1.0 and 2.3 ± 1.1 µg/kg, respectively.
Time-Dependent Changes in Platelet Aggregation, Fibrinolytic Activity, and Peripheral Serotonergic Measures in Rats Subjected to Water Immersion Restraint Stress
Authors: Malyszko J. , Urano T. , Takada Y. , Takada A.
Published: May 2009

The effects of water immersion restraint stress on collagen-induced platelet aggregation in whole blood, and on the fibrinolytic and serotonergic systems in rats have been studied. One hour long stress caused a release of tissue plasminogen activator (tPA) into the blood and a shortening of euglobulin clot lysis time (ECLT), whereas restraint of longer duration was responsible for a reduction in platelet aggregation, an elevation in the activity of plasminogen activator inhibitor with a concomitant fall in tPA and a prolongation of ECLT relative to controls. Whole-blood and plasma serotonin and its metabolite 5-hydroxyindoleacetic acid were also higher in the stressed rats and whole-blood serotonin level showed a negative correlation with tPA in the stressed rats. Either stress and/ or its duration are responsible for changes in both fibrinolytic and serotonergic systems.
Alterations in Fibrinolytic and Protein C Pathways in Gynaecological Surgery: Low Molecular Weight Heparin Prophylaxis
Authors: Estellés Amparo , Gilabert Juan , España Francisco , Vila Juan , Martinez Marcial , Hendl Sylvia , Aznar Justo
Published: May 2009

Several parameters of fibrinolytic and protein C pathways were evaluated in three groups of patients with high (HR), moderate (MR) and low (LR) postoperative thrombotic risk undergoing major gynaecological surgery. The HR and MR groups were subjected to low molecular weight heparin (LMW) prophylaxis. A significant increase in plasminogen activator inhibitor type 1 (PAI-1) antigen and activity levels was observed in the HR patient group in comparison with the MR and LR groups in the preoperative and early postoperative period. In all the groups studied, the maximum increase in the levels of PAI-1 was seen on day 1 after surgery. However, the D-dimeric levels reached the highest level on day 7. A significant increase in activated protein C:α1antitrypsin (APC:α1AT) complex levels was observed in the HR group in comparison with the LR group, and a strong decrease in protein C inhibitor in the early postoperative period was detected in all the groups. In spite of heparin prophylaxis, 2 HR patients were diagnosed as deep vein thrombosis (DVT) during the postoperative period. Both patients showed pre-operative levels of PAI-1 antigen or activity and APC:α1AT complexes above the mean + 1 SD of the pre-operative levels in the HR group. In conclusion, in HR patients a hypofibrinolytic and hypercoagulable state was detected in the pre-operative and early postoperative periods. The prophylactic LMW heparin dose used in the present report (20 mg/day × 7) was insufficient to prevent DVT in the HR group. At present our HR patients are given higher doses of LMW heparin (40 mg/day × 7).
Effects of Recombinant Hirudin on D Dimer Levels before and after Experimental Venous Thrombosis
Authors: Monreal Manuel , Angles Ana María , Monreal Luis , Roncales Javier , Monasterio Jasone
Published: May 2009

In a randomized, blind study, the effect of saline, a low-molecular-weight heparin (Fragmin), and a recombinant hirudin (CGP 39393) on thrombin-antithrombin (TAT) complexes and D dimer (DD) levels were studied in 60 rabbits. The drugs were always injected subcutaneously 2 h before the induction of thrombosis in the jugular vein by a combination of endothelial damage and flow reduction. A sample of blood was obtained just before surgery, and a further sample was obtained 10 min after thrombus formation. No significant differences were found in TAT plasma levels between the different study agents, either before or after thrombus development. However, 2 h after drug administration DD values were significantly lower in hirudin-treated animals (292 ± 69 vs. 372 ± 138 ng/ml; p < 0.05). Then, after thrombus formation, DD levels significantly increased in all three groups of animals, as compared to baseline levels. But the increase was significantly higher in hirudin-treated rabbits: DD levels after thrombus development were significantly higher in this group as compared to placebo (779 ± 188 vs. 664 ± 152 ng/ml; p < 0.05). There are no previous reports in the literature about the effect of hirudin on DD levels. Our hypothesis is that the effect of hirudin on DD may be the result of its ability to inhibit the thrombin-induced thrombus growth. If the thrombus is not allowed to grow then it will lyse more quickly, producing more DD and the process will not be impaired by the constant deposition of fibrin. Alternatively, clot-bound thrombin could be inhibited by hirudin (and not by low-molecular-weight heparin), thereby preventing local activation of blood platelets.
Preventive Effect of Argatroban on Ellagic Acid-Induced Cerebral Thromboembolism in Rats
Authors: Hara Tsuyoshi , Iwamoto Masahiro , Ishihara Masanao , Tomikawa Munehiro
Published: May 2009

The preventive effect of argatroban, a synthetic thrombin inhibitor, on cerebral infarction was evaluated with ellagic acid (EA)-induced cerebral thromboembolism in rats. Platelet-rich thrombi containing fibrin and EA crystal were formed in the microarteries in the affected hemisphere by the injection of EA suspension into the cerebral arteries. The mortality in saline control was over 80% 6 h after the EA injection. Argatroban decreased the mortality to 0% at a dose of 3 mg/kg/h, and significantly reduced the ischemic area in the affected cerebral hemisphere. Heparin also decreased the mortality to 30% at a dose of 600 U/kg/h, but marked bleeding was observed at the incised wound. These findings suggest that argatroban is a more effective and safer anticoagulant than heparin for the prevention of ischemic damage on cerebral thrombosis.
The Influence of Heparin and Protamine Sulfate on Platelet ADP and Platelet Factor 4 Release and the Expression of Glycoprotein llb/llla
Authors: Storck J. , Höllger N. , Zimmermann R.E.
Published: May 2009

We present results concerning the pathogenic mechanism of heparin-induced thrombocytopenia type I. An ELISA was developed for directly measuring the expression of glycoprotein IIb/IIIa (GPIIb/IIIa) on platelets in the presence and absence of ADP and under the influence of various heparins. In addition, the release of ADP and platelet factor 4 (PF4) was measured in platelet-rich plasma. Heparin also induced the expression of GPIIb/IIIa without prior stimulation with ADP. On the other hand we could demonstrate that the addition of heparins and protamine sulfate to platelets resulted in a significant release of intracellularly stored ADP and PF4. These results suggested that heparin(oid)s modulate the expression of GPIIb/IIIa with ADP as a mediator, and that protamine sulfate is contraindicated as an antidote in heparin-induced thrombocytopenia.
Single Nucleotide Change in the Cannabinoid Receptor-1 (CNR1) Gene in Colorectal Cancer Outcome
Authors: Bedoya Fernando , Rubio Juan C. , Morales-Gutierrez Carlos , Abad-Barahona Alfredo , Lora Pablos David , Meneu Juan C. , Moreno-Gonzalez Enrique , Enriquez de Salamanca Rafael , Vegh Irene
Published: May 2009

The cannabinoid receptor-1 (CNR-1) and endogenous agonists of this receptor are present in the central and peripheral nervous systems including the gastrointestinal nervous system. The surgically rejected specimens of human colorectal cancers and paired normal tissues were studied to detect mutations in the CNR1 gene by sequencing method. The results were compared to clinicopathological parameters and correlated with overall survival time. Sixty-three colorectal cancer patients, who underwent surgical excision of colorectal carcinoma, were included in this study. The coding region of the CNR1 gene was studied: a nucleotide change (G→A) at position 1359 was identified by direct sequencing of PCR. Thirty-eight patients had the G/G genotype (wild type) in tumor areas and 25 patients had G/A heterozygous or A/A homozygous genotype. Univariate analysis revealed 2 independent variables associated with CNR1 gene mutation. The results show that the patients with Dukes stage C and D had a 2.9 times (p = 0.04) and patients that were lymph node positive had 2.8 times (p = 0.05) greater probability of nucleotide change in CNR1 gene. Genotype G/A plus A/A had a shorter overall survival time than G/G wild-type patients (p < 0.05). Indeed nontumor paired colorectal tissues showed nucleotide change. A large number of patients with mutation in the CNR1 gene were observed. These preliminary findings highlight the importance of further studies in the use of cannabinoid analogs as receptor ligands to analyze potential therapeutic effects.
Paclitaxel, Estramustine and Carboplatin Combination Chemotherapy after Initial Docetaxel-Based Chemotherapy in Castration-Resistant Prostate Cancer
Authors: Sella A. , Yarom N. , Zisman A. , Kovel S.
Published: May 2009

Objectives: Management of castration-resistant prostate cancer after docetaxel has become an unmet need for which various agents have been investigated. We report our experience with a paclitaxel-based regimen. Methods: From February 2004 to November 2007, 15 patients (PTS) received paclitaxel 80 mg/m2 weekly on day 1, carboplatin (AUC = 6) on day 1 every 21 days and estramustine 140 mg on days –1, 0 and 1 every week. Results: Patient characteristics are: median age 67 years (range 44–81), median performance status (Eastern Cooperative Oncology Group) 1 (range 0–2) and median prostate-specific antigen 67.5 ng/ml (range 1.5–480). All PTS had soft-tissue and 12 (80%) also had osseous disease. A >50% decrease in prostate-specific antigen levels occurred in 9 PTS (60%, 95% CI 32–84). Responses included a partial response in 6 (40%, 95% CI 16–68) and stable disease in 5 PTS (33%). Median duration of progression-free survival was 4.0 months (range 1.1–13) and median survival was 14.6 months. After a median of 4 cycles (range 1–7), significant toxicity included fatigue grade 3 in 2 PTS (13%), neuropathy grade 2 and grade 4 in 1 patient each, and a single episode of grade 3 edema. Myelosuppression was mild. Two PTS (13%) had urinary tract infection and 1 patient neutropenic fever. One patient died due to brain hemorrhage. Conclusions: Administration of second-line paclitaxel-based chemotherapy after docetaxel therapy is active in PTS with castration-resistant prostate cancer. This regimen is too toxic for palliative therapy. Careful patient selection is needed when this regimen is considered for therapy in these PTS.
The Role of Low-Molecular-Weight Heparins in the Prevention of Venous Thrombosis in Surgery with Special Reference to Enoxaparin
Authors: Haas S.
Published: May 2009

Prophylaxis with low-dose heparin has contributed significantly to the reduction in thromboembolic complications in surgery. Without prophylaxis, the rate of deep-vein thrombosis is about 30% in patients undergoing general surgery, rising up to 70% in orthopedic and trauma surgery. According to Collins et al. [N Engl J Med 1988;318:1162-1172] and Clagett and Reisch [Ann Surg 1988;208:227-240] heparin prevented at least 60% of deep-vein thromboses. Meanwhile, various heparin fragments have become available for clinical use and the question arises whether these low-molecular-weight heparins are equal or even superior to unfractionated heparin in preventing thromboembolic complications. Because of the pharmacological heterogeneity of low-molecular-weight heparins and variations in administered doses, this question can only be partially answered by meta-analysis. However, in summary it can be said that despite the difficulties of and concerns about general assessments, single daily injections of low-molecular-weight heparin are at least as efficacious as multiple daily doses of unfractionated heparin. In particular, enoxaparin 40 mg once a day and enoxaparin 30 mg twice a day seem to be superior to unfractionated heparin in high-risk patients, and adverse drug reactions occur less frequently when this prophylaxis is used.
Tissue Factor Pathway Inhibitor: Regulation Of Its Inhibitory Activity By Phospholipid Surfaces
Authors: Lindhout Theo , Salemink Irene , Valentin Sanne , Willems George M.
Published: May 2009

The basic C-terminus of Tissue Factor Pathway Inhibitor (TFPI) appears to be essential for its anticoagulant activity when tested in a diluted thromboplastin prothrombin time assay. Although the data reported so far have increased our knowledge about the C-terminus as a major binding site for heparin, lipoproteins and phospholipids, it is still unclear how this region of TFPI plays a role in its anticoagulant mode of action. We earlier reported that in the presence of phospholipid the rate of association of factor Xa with full length TFPI (FL-TFPI) is about 10-fold faster than with C-terminus truncated TFPI. This in turn makes that, in vitro, full length TFPI is a more potent inhibitor of tissue factor – factor VIla catalyzed factor X activation than truncated TFPI. Binding studies, utilizing an ellipsometer, revealed that in contrast to the complex of C-terminus truncated TFPI (TFPI1-161) and factor Xa, the FL-TFPI.factor Xa complex has a high affinity for negatively charged phospholipids. However, when examined in a tubular flow reactor containing tissue factor embedded in a phospholipid bilayer composed of 25 mol% phosphatidyl-serine/75 mol% phosphatidylcholine, no differences in the potency of FL-TFPI and TFPI 1–161 to inhibit factor X activation were found. The two variants of TFPI did show an interesting difference though. We found that the quaternary complex of TF.factor VIla.FL-TFPI.factor Xa was much more stable than the complex containing TFPI1-161. This difference could not be attributed to their different phospholipid-binding properties since the same difference in stability was found on membranes that contained only DOPC.
Analysis Of The Kinetics Of Factor X Activation By Tissue Factor-Factor VIIa
Authors: Nemerson Yale
Published: May 2009

In this paper we consider the assumptions that apply to the classical Michaelis-Menten enzyme kinetics and examine their applicability to a two-dimensional catalytic system. While we specifically address the kinetics of factor X activation catalyzed by a complex of tissue factor and factor VIla, these concepts are applicable to any system in which both enzyme and substrate are membrane-bound. We emphasize the fact that the membranes become crowded with substrate and product molecules, thus rendering the assumption of “sparseness” inappropriate. Data from computer simulations are considered as well as preliminary laboratory experiments.
Platelet Activation: New Aspects
Authors: Fox Joan E.B.
Published: May 2009

Work on growth factor receptors in other cells has led to the concept that tyrosine phosphorylation of receptor cytoplasmic domains leads to recruitment of signaling molecules to appropriate sub-membrane locations. Complexes of molecules are assembled through structural motifs that mediate phosphotyrosine-SH2 domain and SH3-proline-rich domain interactions. These interactions lead to activation of signaling molecules, especially activation of members of the Ras superfamily that in turn mediate downstream effects on gene regulation, vesicle movement, and cytoskeletal reorganizations. In platelets, signaling occurs primarily through members of the seven transmembrane-hererotrimeric G-protein coupled family of receptors and through adhesion receptors. The most rapid are of growth in recent years has been the realization that signaling through both G-protein coupled receptors and adhesion receptors is dependent on tyrosine kinase activation, recruitment of complexes of SH2, SH3, and proline-rich signaling molecules to appropriate locations in the cell, and on activation of members of the Ras superfamily of proteins. Because neither G-protein coupled receptors nor adhesion receptors have intrinsic tyrosine kinase activity, mechanisms presumably exist for using non-receptor kinases to initiate tyrosine phosphorylation reactions that in turn lead to the recruitment of signaling molecules. As discussed in this article, many tyrosine kinases exist in platelets and some of these are known to be tyrosine phosphorylated and activated following platelet activation. The theme that is emerging is that these tyrosine kinases may serve to phosphorylate submembranous proteins including receptors for cytoplasmic domains or components of the submembranous cytoskeleton of adhesion-receptor cytoskeleton complexes that can then recruit and activate appropriate signaling molecules. The challenge in future years will be to identity the way in which the activation of tyrosine kinase(s) is induced by receptor activation, identify the tyrosine kinase(s) involved, and identify the way in which specific members of the Ras superfamily activate downstream effectors to induce the responses of platelets to activation.
Genetic Analysis Of The Plasminogen And Coagulation System In Mice
Authors: Carmeliet Peter , Collen Désiré
Published: May 2009

The blood coagulation and the fibrinolytic (or plasminogen/plasmin) systems determine the balance between the formation and dissolution of blood clots, but in addition contribute to the pathogenesis of various cardiovascular disorders such as thrombosis, atherosclerosis and restenosis. Furthermore, they participate in a variety of other (patho)biological processes such as embryonic development, reproduction, wound healing, cancer and brain function. Two recently developed technologies, gene targeting and gene transfer, that allow to manipulate the genetic balance of these proteinase systems in a controllable manner have allowed to more definitively elucidate the biological role of these systems. This review summarizes the insights that have been obtained from the gene targeting studies and discusses the use of adenovirus-mediated transfer of fibrinolytic genes to study and possibly to develop novel strategies for the treatment of restenosis and thrombosis.
Hemorheological Profile In Patients With Cardiovascular Risk Factors
Authors: Vayá A. , Martínez M. , Dalmau J. , Labios M. , Aznar J.
Published: May 2009

In order to find out whether hemorheological alterations precede the atherosclerotic lesions and could constitute an atherothrombotic risk factor, we studied the hemorheological profile in 150 healthy normotensive offspring whose parents were diagnosed as having essential hypertension WHO I-II grade and in another group of 40 children with familial hypercholesterolemia (FH) but without vascular atherosclerosis lesions, whose parents also suffer from FH. In offspring of hypertensive individuals, a significant increase in the fibrinogen level with respect to the control group was found both in males and females. In addition, only the female offspring showed a higher leucocyte count. FH children showed increased ery-throcyte aggregation and increased plasma viscosity with respect to the control group. The fact that the rheological alterations appear prior to the development of the vascular lesion suggests that they could play a role in the pathogenesis of the atherosclerotic process.
Effect of hmg-coa reductase inhibitors on red blood cell membrane lipids and haemorheological parameters, in patients affected by familial hypercholesterolemia
Authors: Martinez Marcial , Vaya Amparo , Marti Roberto , Gil Lorenzo , Lluch Irene , Carmena Rafael , Aznar Justo
Published: May 2009

Eighteen patients with familial hypercholesterolemia treated with lovastatin (40 mg/day) for three months were studied to find out whether the drug induces modifications in the lipid composition of the erythrocyte membrane and whether these induce changes in the rheological behaviour of the red blood cell. Our results show that the changes observed in plasma lipids correlate with a significant decrease in the cholesterol/phospholipid ratio of the red blood cell membrane. These changes in the lipid composition of the cell are statistically related to a decrease in the erythrocyte aggregability and an improvement in blood filterability probably due to an increase in the red blood cell deformability.
Adhesive Proteins At Endothelial Cell-To-Cell Junctions And Leukocyte Extravasation
Authors: Dejana E. , Zanetti A. , Del Maschio A.
Published: May 2009

Endothelial cell junctions are complex structures formed by transmembrane adhesive molecules linked to a network of cytoplasmic/cytoskeletal proteins. At least four different types of endothelial junctions have been described (tight junctions, gap junctions, adherence junctions and syndesmos or complexus adhaerentes). Leukocytes adhesion to endothelial cells is frequently followed by their extravasation. The mechanisms which regulate the passage of leukocytes through endothelial clefts remain to be clarified. Many indirect data suggest that leukocytes might transfer signals to endothelial cells both through the release of active agents and adhesion to the endothelial cell surface. These signals could induce the disorganization of interendothelial junctions and facilitate leukocyte transmigration.
Directed Search For Thrombomodulin Gene Mutations
Authors: Ireland H. , Kyriakoulis K. , Kunz G. , Lane D.A.
Published: May 2009

Thrombomodulin is a principle thrombin receptor located on the vascular endothelium. Thrombomodulin alters the specificity of thrombin, redirecting its procoagulant function to an anticoagulant function by making it a more efficient activator of protein C. While mutation of the genes of other components of this anticoagulant mechanism, protein C, protein S and factor V, is known to predispose towards venous thromboembolism, there are only a few reports of the investigation of thrombomodulin gene mutation. We present the design and evaluation of a strategy to investigate thrombomodulin gene mutation in arterial and venous thrombosis.
Precision And Accuracy Of The International Normalized Ratio In Oral Anticoagulant Control
Authors: van.den.Besselaar A.M.H.P.
Published: May 2009

Precision is defined as the agreement between replicate analyses of the same material. Within-laboratory precision of the prothrombin time (PT) and INR can be optimized by choosing an appropriate combination of thromboplastin and instrument. Accuracy (true value) of the International Sensitivity Index (ISI), required for the calculation of INR, depends on the choice of international reference preparation for the thromboplastin, and on the instrument used by the local laboratory. Interaction between thromboplastin and each patient’s individual coagulation factors influences the accuracy of the INR. The contributions of imprecision, inaccuracy, and interaction effects can be combined to calculate the total uncertainty of the INR using Tomenson’s equation. Confidence intervals for the INR were calculated in typical examples. The 95% confidence intervals of the INR around 3 are approximately as wide as currently recommended therapeutic target ranges.
The Anti-GpIIb-IIIa Agents: Fundamental And Clinical Aspects
Authors: Coller Barry S. , Anderson† Keaven M. , Weisman† Harlan F.
Published: May 2009

The platelet GPIIb/IIIa receptor mediates platelet aggregation induced by all physiologic agonists. Blockade of the receptor, either by monoclonal antibodies or small molecules patterned after the arginine glycine-aspartic acid (RGD) cell recognition domain, prevents arterial thrombosis in animal models much better than does aspirin. c7E3 Fab, the Fab fragment of the mouse/human chimeric antibody 7E3 (abciximab: ReoProTM), was shown to reduce ischemic events after angioplasty when given in conjunction with heparin and aspirin to patients at high risk in the EPIC study, but its was associated with an increase in bleeding. Preliminary data from the subsequent EPILOG study, in which a lower dose of heparin was used, demonstrated efficacy in low risk as well as high risk patients and no significant increase in major bleeding. Preliminary data from the CAPTURE study support the use of c7E3 Fab in patients with unstable angina who are candidates for PTC A within 24 hours. Positive trends toward decreased thrombotic events have also been observed in patients treated with small molecule inhibitors of GPIIb/IIIa receptors. This new class of agents thus holds promise for improving the therapy of angioplasty as well as perhaps other thrombotic phenomena.
Inherited Resistance To Activated Protein C Caused By Presence Of The FV:Q506 Allele As A Basis Of Venous Thrombosis
Authors: Dahlbäck Björn , Zöller Bengt , Hillarp Andreas
Published: May 2009

Inherited resistance to activated protein C (APC) was recently discovered as a cause of familial throm-bophilia and is now known to be the most common genetic risk factor for venous thrombosis. In a majority of cases, APC resistance is associated with a single point mutation in the factor V gene, which results in substitution of arginine (R) at position 506 by glutamine (Q) (FV:Q506). The mutation renders factor Va partially resistant to degradation by activated protein C (APC), which leads to a hypercoagulable state and a life-long 5–10-fold increased risk of venous thrombosis. The previously known inherited deficiencies of antithrombin, protein S or protein C, are in western societies together found in less than 10–15% of thrombosis patients, whereas APC resistance is present in 20 to 60% of the patients. A functional APC resistance test, which includes predilution of the patient plasma with factor V deficient plasma, is 100% sensitive and specific for the presence of FV:Q506. The FV:Q506 allele is common in populations of Caucasian origin (prevalence ranging between 1 and 15%), whereas it is not found in certain other ethnic groups such as in Japanese and Chinese. The thrombotic risk in individuals with APC resistant may be further increased by other genetic defects such as protein C or protein S deficiency and by exposure to circumstantial risk factors such as oral contraceptives, pregnancy, immobilisation and surgery.
Diagnosis And Clinical Characteristics Of Inherited Activated Protein C Resistance
Authors: Samama M.M. , Simon D. , Horellou M.H. , Trossaërt M. , Elalamy I. , Conard J.
Published: May 2009

The diagnostic strategies and clinical characteristics of thrombophilia associated with heterozygous or homozygous factor V Leiden mutation have been determined according to the literature and to a personal study in 51 families. Factor V mutation was present in the 51 propositi and in 84 out of 125 family members (81 heterozygous, 3 homozygous). Venous thrombosis was observed in all the propositi, in 17 of the 84 family members with the mutation and in 6 of the 41 with a normal APC resistance test and no mutation. An associated protein C or protein S deficiency was present in 5 families (10 %). The most frequent clinical manifestations were superficial or deep vein thrombosis and/or pulmonary embolism, but also thrombosis at an unusual site (cerebral, mesenteric or central retinal vein). A causal relationship is frequently difficult to demonstrate. A precipitating factor was observed in 84 % of cases and a recurrent thrombotic episode occured in 50 % of propositi. The risk of thrombosis associated with pregnancy was high in the post-partum period, especially in homozygous women. In the 28 homozygous subjects, markers of coagulation activation were frequently elevated in untreated patients. Finally, the efficacy of anticoagulant treatment is suggested but the long period often observed between treatment interruption and a recurrence does not militate in favour of long term treatment.
Regulation Of Fibrinogen Biosynthesis By Cytokines, Consequences On The Vascular Risk
Authors: Vasse M. , Paysant J. , Soria J. , Collet J.P. , Vannier J.P. , Soria C.
Published: May 2009

High level of fibrinogen in plasma is recognised as an important vascular risk factor. However, it is not known if the increase in fibrinogen is directly responsible for the vascular risk or is a marker of vascular inflammation. Our data strengthen the hypothesis that the fibrinogen level is a marker of vascular disease, since a parallel effect of cytokines on fibrinogen biosynthesis and on vascular injury was noted. Among the cytokines which induce the synthesis of fibrinogen, oncostatin M (OSM) is the most potent cytokine synthesised by activated monocytes for inducing fibrinogen synthesis by Hep G2 cells (human hepatoma cell line). Interestingly at the same concentrations needed for fibrinogen biosynthesis, OSM induces smooth muscle cell proliferation. In contrast, the cytokines IL-4, IL-10 and IL-13 which have a protective effect against vascular injury leading to atherosclerosis, dose dependently down regulate the biosynthesis of fibrinogen. This was due to both a decrease of IL-6 induced fibrinogen synthesis by hepatocytes, evidenced by a decrease in fibrinogen secretion in the medium and beta chain mRNA expression and to an inhibition of production of the hepatocyte-stimulating activity for fibrinogen biosynthesis (HSF) by LPS-activated monocytes. Noteworthingly, IL-10 induces a significant decrease of the production of OSM by LPS-activated monocytes. In situ activation of monocytes by cytokines in the vessel wall could also contribute to the deposition of fibrin(ogen) derivatives, identified as pathogenic factor.
Prolonged prophylaxis against postoperative venous thromboembolism
Authors: Bergqvist David
Published: May 2009

This review deals with the problem of delayed thrombosis and thereby the potential need of prolonged prophylaxis. The risk of late thrombosis and pulmonary embolism is discussed from pathogenetic factors and data on frequencies of thromboembolic complications in the literature. The problems concerning long term or prolonged prophylaxis are indicated and studies on prolonged prophylaxis – our own included – are analyzed. There is an urgent need to define which risk factors motivate prolonging thromboprophylaxis for more than the standard 7–14 days.
G-CSF for Treatment Intensification in High-Grade Malignant Non-Hodgkin’s Lymphomas
Authors: Steinke B. , Manegold Ch. , Freund M. , Reinold H.-M. , Fischer J.-Th. , Arnold H. , Lengfelder E. , Lutz M. , Zwingers T. , Münz A. , Hecht T.
Published: May 2009

Background: Hematologic growth factors may allow those intensification of chemotherapy possibly leading to an improvement of treatment results in high grade malignant non-Hodgkin’s lymphomas. In the present study the possibility of reducing the time intervals between treatment cycles of chemotherapy was examined. Patients and Methods: In 24 patients with high grade malignant lymphomas intervals between VIM/CHOP chemotherapy cycles were reduced from the original 21 to 17 and even 14 days. G-CSF 5 µg/kg was administered s.c. for ten days after each treatment cycle. Results: It was possible to apply chemotherapy in the scheduled, reduced interval in more than 80% of the cycles. Major side effects of G-CSF treatment were observed in only two patients experiencing bone pain. Other toxicity was chemotherapy related and seldom severe. Conclusions: With the administration of G-CSF, treatment intervals of VIM/CHOP chemotherapy can safely be reduced. Whether this will lead to better treatment results needs further examination.
Thrombopoietin
Authors: Baatout Sarah
Published: May 2009

The regulator of platelet count is believed to be thrombopoîetin (mpl ligand). It is thought to act on the megakaryocytic lineage affecting the proliferation of committed cells, the maturation of megakaryocytes and the blood platelet levels by activation of its receptor (the c-mpl). Recently, it has been purified and sequenced. Thrombopoîetin offers potential applications for treatment of thrombocytopenia.
Urinary Procoagulant Activity and Tissue Factor Levels in Patients with Diabetes mellitus
Authors: Qi Hasenqiqigel , Koyama Takatoshi , Nishida Kenji , Miyasaka Nobuyuki , Hirosawa Shinsaku
Published: May 2009

We characterized a factor important for the normal procoagulant activity in human urine and measured urinary tissue factor (TF) and thrombomodulin (TM) levels in patients with diabetes mellitus (DM). Urine shortened normal plasma-based clotting time, which is inhibited by antibody to the human TF. TF in urine presents in membrane-nonassociated and associated forms. The urine TF antigen levels in DM patients were significantly lower than those in healthy subjects, particularly in DM patients without retinopathy. Levels of TM in patients with DM and normal subjects were similar. Although urinary TF might be necessary to repair tissue injury of damaged sites in the excretory pathway of urine, the clinical relevance of the reduced TF in the urine needs further investigation.
Low Molecular Weight Heparin and Unfractionated Heparin for Prevention of Thrombo-Embolism in General Surgery: A Meta Analysis of Randomised Clinical Trials
Authors: Palmer A.J. , Schramm W. , Kirchhof B. , Bergemann R.
Published: May 2009

Low molecular weight heparin (LMWH), unfractionated heparin (UFH) and warfarin were compared with respect to efficacy and safety in the prevention of thrombo-embolism in general surgery. Meta-analysis (MA) with a priori definition of the MA protocol was used to combine the results from randomised trials with patients who underwent general surgery and deep-vein thrombosis (DVT) prophylaxis with LMWH, UFH or warfarin. Forty-four studies were identified for assessment and 33 were included, however, none for warfarin. For efficacy (DVT and pulmonary embolism) and major bleeding, no significant difference between the LMWH- and UFH-treated groups was demonstrated. The relative risk of minor bleedings for LMWH versus UFH was 0.75 (0.64-0.88; 95% confidence interval) and is significant (p < 0.05). Within the limitations of the MA, LMWH and UFH did not differ significantly in terms of prevention of thrombo-embolism, but LMWH had a significantly better safety profile. On this basis, LMWH may be preferable to UFH in the prevention of thrombo-embolism in general surgery.
Platelet Count and the Risk of Bleeding in Hospitalized Patients with Venous Thromboembolism Starting Anticoagulant Therapy
Authors: Monreal Manuel , Urrutia Agustin , Marti Salvador , Cuxart Alfons , Roncales Javier
Published: May 2009

In a series of patients with pulmonary embolism (PE) we have previously demonstrated that the risk of recurrent PE was inversely correlated to platelet count (PIC) levels. To find out whether PIC levels were also associated to a different incidence of heparin-related bleeding complications, we report our experience with 1,103 consecutive patients with venous thromboembolism (VTE) receiving full-dose heparin therapy. Six points of clinical and laboratory information were recorded on admission and then compared to the development of bleeding: the patient’s age and sex; the etiology of VTE; the type of heparin used (unfractioned, UFH, vs. low-molecular-weight, LMWH), the presence or lack of PE findings on lung scan, and the PIC levels on admission. Bleeding occurred in 64/1,103 patients (6%). Patients who bled were significantly older than those who did not (72 ± 11 vs. 64 ± 17 years; p = 0.0005). There were no significant differences in bleeding rate according to any of the risk factors that could have predisposed to VTE, but patients treated with UFH bled significantly more frequently than those on LMWH (48/636 vs. 16/467; odds ratio: 2.30; 95% confidence interval: 1.25-4.28). Finally, mean PIC levels were significantly lower at VTE diagnosis in patients who subsequently bled (227 ± 112 vs. 262 ± 110 × 109 liters-1; p = 0.01). The logistic regression analysis confirmed that all three variables were independent risk factors for bleeding complications. This is the first study to demonstrate that PIC levels (within the normal range) are inversely correlated with the risk of heparin-related bleeding. These findings may be of interest not only from the point of view of pathogenesis but also clinically, as they may be used in the decision as to which VTE patients could receive heparin therapy at home.
Factor-V (Arg506→GIn) Mutation in Ischemic Cerebrovascular Disease
Authors: Iniesta Juan-Antonio , Corral Javier , Fernández-Pardo Jacinto , González-Conejero Rocío , Vicente Vicente
Published: May 2009

Factor V Leiden is already well established to be involved in venous thrombosis but not in coronary heart disease. Results are conflicting and even antagonistic in cerebrovascular disease (CVD). In this study we examined the prevalence of factor V Leiden in 125 consecutive patients with ischemic CVD, 12 additional selected CVD patients with the first CVD episode before the age of 45 years, and 102 controls from the same area. Identification of the mutation was achieved using two molecular methods. The prevalence of factor V Leiden in patients with CVD was similar to that in the normal population. The presence of the mutation was independent of the age and severity of the ischemic episode. Finally, no significant clinical differences were found between patients with and those without factor V Leiden. Therefore, factor V Leiden cannot be considered as a genetic risk factor for CVD.
Pre-Analytical Variation in the Measurements of Sensitive Markers of Coagulation and Fibrinolysis: The Influence of Venipuncture and Mixing of Blood
Authors: Iversen Lene H.
Published: May 2009

The techniques adopted for venipuncture and the mixing of aspirated blood with anticoagulant were evaluated for their possible contribution in pre-analytical variation in estimating plasma prothrombin fragment 1+2 (Fl+2), thrombin-antithrombin complex (TAT), soluble fibrin and total fibrin(ogen) degradation products. Antecubital vein blood samples were simultaneously collected in 20 subjects from either arm by technologists with high and less blood sampling experience employing a crossover design. Fl+2 and TAT were significantly higher in plasma obtained by a less experienced technologist. Three different mixing procedures of blood with anticoagulants did not influence the levels of the markers. The results emphasize that experienced technologists should preferably be selected for collecting blood for analysis of coagulation markers.
Fibrinopeptide A, Prothrombin Fragment 1 + 2, Thrombin-Antithrombin Complex and D Dimer before and after Injection of a Nonionic Contrast Medium (lohexol)
Authors: Sorano G.G. , Paoletti P. , Casciu G. , Mameli G. , Marongiu F.
Published: May 2009

The principal aim of this study was to evaluate, on biochemical grounds, whether injection of a low-osmolar nonionic contrast medium (iohexol) can induce a prothrombotic state and/ or a change in fibrinolysis. Fifteen patients were submitted to urographic examination and the assays listed below were performed: before the injection (To), 1 h after (Ti), and 24 h after (T24) the injection of the contrast medium. The following assays were performed: fibrinopeptide A (FPA), prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), and D dimer (D-D). The assays were carried out on 6 of the patients to whom a saline infusion was administered. Only a mild statistically significant increase was found in FPA levels at 1 h after injection of the contrast medium (mean and CI 95%: T0 4.4, 3.7-5.5; T, 6.0, 4.9-9.1; p = 0.003). F1+2, TAT and D-D did not show any significant change after the injection. These findings show that after injection of iohexol, only a mild, though statistically significant, increase in FPA levels was observed as an expression of increased thrombin activity. In the absence of any significant increases in TAT, F1+2 and D-D, we have no evidence of a prethrombotic state.
Analysis of Glycoprotein la, lb, lIb and IV RNA in Platelets: Quantitative Determination Using Fluorescence-Based Polymerase Chain Reaction
Authors: Seidl C. , Siehl J. , Kirchmaier C.M. , Seifried E.
Published: May 2009

The aim of this study was to analyze the RNA level of glycoproteîn (GP) receptors in platelets. We have therefore established a quantitative fluorescence-based polymerase chain reaction (PCR) to analyze GP la, lb, lIb, and IV RNA. Isolation of platelet RNA was performed by guanidium isothiocyanate/phenol chloroform extraction. An internal standard consisting of cRNA copies from plasmid pAW109 was included before reverse transcription in each RNA sample and PCR amplification was performed using fluorescence-labeled primers. Subsequently, PCR fragments were separated by gel electrophoresis and quantitation of the GP-specific fragments was done by measuring the fluorescence intensities in comparison to the internal standard. Relative amounts of GP RNA/platelet were calculated taking into account the number of platelets used for isolation of platelet RNA and the platelet size as determined by flow-cytometric analysis. Using this method we analyzed the GPIa, lb, lIb and IV RNA content of platelets in healthy blood donors. In parallel experiments the number of GP cell surface receptors was measured by flow-cytometric analysis and correlated with the GP-specific RNA content. This method may be useful to study the GP-specific RNA content in platelets as well as in other tissues, such as megakaryocytes, especially in patients with congenital or acquired platelet function disorders.