bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lupus Anticoagulants and Thrombosis: Clinical Association of Different Coagulation and Immunologic Tests
Authors: Dlott Jeffrey , Norbis Francesca , Ruggeri Luisa , Cler Linda , Triplett Douglas , Barbui Tiziano , Galli Monica 
Published: March 2018

SummaryThe dilute Russell’s viper venom time (dRVVT) and the kaolin clotting time (KCT) are two among the most commonly used coagulation tests for the detection of lupus anticoagulants. The dRVVT seems superior to the KCT in identifying LA-positive patients at risk of thrombosis. However, this relationship is greatly influenced by both the source of reagents and the instrumentation employed to carry out the assays. Therefore, 4 dRVVTs (“home-made” dRVVT, DVV test, Bioclot LA, LA Screen), and one KCT (Kaoclot) were performed in two centers and compared for their retrospective correlation with the thrombotic complications of 72 patients with a previously established diagnosis of lupus anticoagulants. Two other assays (“home-made” KCT, and Colloidal Silica Clotting Time, CSCT) were performed in one of the two centers, and compared with Kaoclot for their clinical correlations in the same population of patients, 44 of whom (61%) had suffered from arterial and/or venous thrombosis. A rather good degree of inter-laboratory and inter-assay correlations of the different tests was found. However, a statistically significant association with thrombosis was found only with the coagulation profile generated using the “homemade” dRVVT. When the commercially available dRVVTs were used, none of the coagulation profiles remained associated with thrombosis. When the assays were analyzed separately, the association with thrombosis was statistically significant for LA screen (p = 0.0019), DVV test (p = 0.0043), and Bioclot (p = 0.0255), and of borderline significance for the “home-made” dRVVT (p = 0.0503) in one center. This last assay was also significantly associated with thrombosis in the other center (p = 0.0139). When venous and arterial thrombosis were considered separately, DVV test was statistically associated with venous thrombosis in both centers (p = 0.0076 and p = 0.0187, respectively), and LA screen in one center (p = 0.0303). No dRVVT was found to correlate with arterial thrombosis. Kaoclot, Colloidal Silica Clotting Time, and the “home-made” KCT did not correlate with thrombosis. The prevalence of IgG and/or IgM antibodies to cardiolipin, β2-glycoprotein I and prothrombin were 74%, 86% and 85%, respectively. Increased titers of IgG anticardiolipin antibodies were associated with arterial thrombosis (p = 0.0375), whereas IgM anti-β2-glycoprotein I antibodies were associated with venous thrombosis (p = 0.0433). In conclusion, these retrospective data support the notion that the dRVVT, rather than other coagulation or ELISA tests, are able to identify lupus anticoagulant-positive patients at risk of thrombosis. This property appears common to several commercially available dRVVT kits, making this type of assay the ideal target of future efforts of laboratory standardization.
Smooth Muscle Cell Migration Promoting Activity of Plasma Predicts Restenosis in Patients with Peripheral Arterial Occlusive Disease Undergoing Angioplasty
Authors: Janisch Sandra , Kvas Erich , Schnedl Wolfgang , Binder Bernd , Wojta Johann , Korninger Christian , Roller Regina 
Published: March 2018

SummaryEfficacy of percutaneous transluminal angioplasty (PTA) is limited by restenosis occurring in a large proportion of patients. Smooth muscle cell (SMC) migration is a major pathomechanism of restenosis. We studied SMC migration inducing activity of plasma from patients with peripheral arterial occlusive disease (PAOD) undergoing PTA.SMC migration was determined in a two-dimensional assay system after addition of 1/25 plasma dilutions. Mean increase in migration area was 65.5 ± 33.8% in normal controls and 67.7 ± 53.2% in patients with PAOD. 6 hours after PTA, plasmatic migration inducing activity was largely unchanged. In 19/30 patients with restenosis (6 months after PTA) migration promoting activity (82.7 ± 60.0) was significantly higher than in 11/30 patients with patent vessels (41.8 ± 21.0; p = 0.03). No correlation of clinical risk factors with outcome was observed. A weak correlation was found between plasmatic migration promoting activity and levels of epidermal growth factor and transforming growth factor-β.The capacity of human plasma to stimulate SMC migration in tissue culture can be used to assess the risk for restenosis after PTA in patients with PAOD.
Rare Coagulation Disorders
Authors: Peyvandi Flora , Mannucci P. M. 
Published: March 2018

SummaryThe type of hemorrhagic manifestations that occur in patients with recessively transmitted coagulation disorders and their optimal treatment are not well established as for hemophilia A and B and von Willebrand disease, due to the rarity of these disorders. In a Muslim country like Iran where consanguineous marriages are frequent these disorders are less rare. We chose to evaluate the pattern of bleeding symptoms in 237 Iranian patients with the inherited deficiencies of fibrinogen, factor II, combined factor V and factor VIII, factor V, factor VII and factor X. Considering “severe” life-endangering hemorrhages such as those in the CNS, gastrointestinal tract and from the umbilical cord and those potentially handicapping such as hematomas and hemarthroses; and “mild” epistaxis, menorrhagia, hematuria, oral and postsurgical bleeding, it would appear the most severe diseases are factor X and factor II deficiencies. For the remaining defects only a minority of patients, even those with unmeasurable plasma levels, had life-endangering hemorrhages or muscoloskeletal disabilities as a consequence of hemarthroses and hematomas. The relatively mild severity of clinical manifestations in recessive coagulation disorders commands safety as the primary criterion in the choice of replacement material for treatment. Hence, virally inactivated plasma and factor concentrates should be the products of choice.
Hemostatic Activation under Anticoagulant Treatment: A Comparison of Unfractionated Heparin vs. Nadroparin in the Treatment of Proximal Deep Vein Thrombosis
Authors: Marchetti O. , Haeberli A. , Mombelli G. , Stricker H. 
Published: March 2018

Summary
Background: Multiple clinical trials have been performed to compare standard heparin with low molecular weight heparin in the therapy of deep vein thrombosis, but little is known about the time course of the markers of hemostatic system during the treatment with these two heparin regimens.
Methods: Twenty patients with proximal deep vein thrombosis confirmed by duplex ultrasound and phlebography were randomly assigned to either unfractionated heparin (UH) given as an intravenous bolus of 80 U/kg followed by a constant infusion of 18 U/kg/h, or nadroparin 185 AXa IU/kg once daily subcutaneously. Oral anticoagulants were started at day 4. Markers of hemostatic activation (F1+2, FPA, TAT, D-dimer) were measured daily for 4 days. Primary end-points were the time course of these markers; secondary endpoints consisted in the evaluation of thromboembolic and hemorrhagic complications by clinical outcome and Marder score.
Results: Treatment with UH resulted in a rapid achievement of therapeutic heparin levels. UH reduced markers of fibrin formation and fibrinolysis more rapidly than nadroparin (p < 0.05). Within the nadroparin group activation of prothrombotic markers four hours after the subcutanous injection (peak level) was significantly lower when compared with the time prior to injection (trough level). Secondary endpoints showed no significant difference between the two groups.
Conclusion: Continuous intravenous perfusion of UH administered on a basis of a weight-adjusted nomogram controlled markers of the hemostatic system more rapidly than once-daily subcutaneously administered weight-adjusted nadroparin.
The Risk of Fetal Loss in Family Members of Probands with Factor V Leiden Mutation
Authors: Tormene Daniela , Simioni Paolo , Luni Sonia , Innella Barbara , Sabbion Paola , Girolami Antonio , Prandoni Paolo 
Published: March 2018

SummaryIn order to investigate the risk of fetal loss in carriers of factor V Leiden who are family members of probands with this mutation, we performed a retrospective cohort study including 109 women who had been pregnant at least once and were family members of 61 probands with venous thromboembolism and a single identified factor V Leiden mutation. The rate of pregnancies ending in unexplained fetal loss, early miscarriage, late miscarriage or stillbirth in women with the factor V Leiden was compared with that of women with normal genotype. In the 65 women who were carriers of factor V Leiden 31 of the 191 pregnancies (16.2% per pregnancy ) resulted in unexplained fetal loss, as compared to 13 of the 121 pregnancies (10.7% per pregnancy) in the 44 non-carriers (relative risk, 1.5; 95% CI, 0.8-3.2). After the first trimester of pregnancy, 25 pregnancies (13.1% per pregnancy) among carriers of factor V Leiden ended in fetal loss, as compared to 7 (5.8% per pregnancy) among females with normal genotype (relative risk, 2.3; 95% CI, 1.01 to 5.1). We conclude that carriers of factor V Leiden who are family members of probands with this mutation have a statistically significant and clinically important risk of late miscarriage or stillbirth. Studies addressing the benefit-to-risk ratio of adopting routinary thromboprophylactic measures following the first trimester of pregnancy in these women are strongly indicated.
Erythropoietin Improves Signaling through Tyrosine Phosphorylation in Platelets from Uremic Patients
Authors: Estebanell Eva , Cases Aleix , López-Pedret José , Castillo Ricardo , Ordinas Antonio , Escolar Ginés , Diaz-Ricart Maribel 
Published: March 2018

SummaryErythropoietin has shown to be effective in the correction of the hemostatic defect present in uremic patients. We have investigated the possible effect of recombinant human erythropoietin (rHuEPO) on the signaling processes occurring in platelets. Platelet suspensions were obtained from hemodialyzed patients before and after at least one month of initiating treatment with rHuEPO. Aliquots of non-activated or thrombin-activated platelets were treated to obtain platelet lysates or processed to extract platelet cytoskeleton. Samples were resolved by 8% SDS-polyacrylamide gel electrophoresis followed by Western blotting. After thrombin activation, proteins p120, p85, p78, p75, pp62, pp60, p59, p58, p56, p54 and p52 associated with the Triton-insoluble cytoskeletal fraction appeared phosphorylated in control profiles. In profiles from platelets obtained from uremic patients before treatment with rHuEPO, only proteins p58 and p56 appeared clearly and p54 was slightly phosphorylated. However, in platelets from the same patients under rHuEPO treatment, thrombin-induced phosphorylation improved to levels even above those observed in control profiles. Specially, the band at 54KDa appeared consistently more phosphorylated in all the patients under rHuEPO treatment. Although it is accepted that part of the hemostatic effect of erythropoietin is mediated by an increase in hematocrit, our study suggests that it enhances platelet signaling in uremic platelets which may explain the improvement of platelet response to activating stimulus before clinically noticeable elevation of hematocrit.
Abbrevations: rHuEPO = recombinant human erythropoietin; SDS-PAGE = sodium dodecyl sulphate-polyacrylamide gel electrophoresis; CPD = citrate/phosphate/dextrose; PRP = platelet-rich plasma; HBSS = Hanks’ balanced salt solution; EGTA = ethylene glycol bis (β-aminoethylether)-N,N,N’,N’-tetraacetic acid; EDTA = ethylenediaminetetraacetic acid, PMSF = phenylmethylsulphonyl fluoride, ECL = enhanced chemiluminiscence
Role of Intracellular Signaling Events in ADP-induced Platelet Aggregation
Authors: Daniel James , Dangelmaier Carol , Jin Jianguo , Kim Young , Kunapuli Satya 
Published: March 2018

SummaryHuman platelets express two distinct G protein-coupled ADP receptors, one coupled to phospholipase C through Gq, P2Y1, and the other to inhibition of adenylyl cyclase through Gi, P2TAC. We have recently shown that concomitant intracellular signaling from both the P2TAC and P2Y1 receptors is essential for ADP-induced platelet aggregation. Previous studies have tested whether ADP causes a decrease in the basal cAMP level and this reduction promotes platelet aggregation, but did not study the effect of decreased cAMP levels when the Gq pathway is selectively activated. Since we are now aware that platelet aggregation requires activation of two receptors, we investigated whether the function of P2TAC receptor activation, leading to inhibition of platelet adenylyl cyclase, could be replaced by direct inhibition of adenylyl cyclase, when Gq pathway is also activated, a possibility that has not been addressed to date. In the present study, we supplemented the P2Y1 mediated Gq signaling pathway with inhibition of the platelet adenylyl cyclase by using SQ22536 or dideoxyadenosine, or by selective activation of the α2A adrenoceptors with epinephrine. Although SQ22536, dideoxyadenosine, and epinephrine reduced the cAMP levels, only epinephrine could mimic the P2TAC receptor mediated signaling events, suggesting that reduction in basal cAMP levels does not directly contribute to ADP-induced platelet activation. Adenosine-5’-phosphate-3’-phosphosulfate, a P2Y1 receptor antagonist, completely blocked ADP-induced inositol 1,4,5-trisphosphate and inositol 1,3,4-trisphosphate formation suggesting that P2TAC-mediated activation of Gi (or other G proteins) does not activate phospholipase C. These results suggest that a signaling event downstream from Gi, independent of the inhibition of platelet adenylyl cyclase, contributes to αIIbβ3 activation.
Low Molecular Weight Heparin versus Acenocoumarol in the Secondary Prophylaxis of Deep Vein Thrombosis
Authors: Bielska-Falda H. , Noszczyk W. , Bielawiec M. , Witkiewicz W. , Filipecki S. , Michalak J. , Ciesielski L. , Mackiewicz Z. , Czestochowska E. , Zawilska K. , Cencora A. , Lopaciuk S. ,   among others
Published: March 2018

SummaryThe aim of this study was to determine the efficacy and safety of subcutaneous weight-adjusted dose low molecular weight heparin (LMWH) compared with oral anticoagulant (OA) in the prevention of recurrent venous thromboembolism. In a prospective multicenter trial, 202 patients with symptomatic proximal deep vein thrombosis (DVT) were included. As soon as the diagnosis of DVT was confirmed by phlebography, 101 were randomly assigned to receive LMWH (nadroparin) for secondary prophylaxis and 101 to receive OA (acenocoumarol). Patients in both groups were initially treated with nadroparin in a dose of 85 anti-Xa IU/kg s.c. every 12 h. Secondary prophylaxis with either nadroparin, 85 anti-Xa IU/kg s.c. once daily, or acenocoumarol was continued for at least 3 months. Three patients in the LMWH group and 6 in the OA group were excluded from analysis for various reasons. During the one-year combined secondary prophylaxis and surveillance period, 7 of of the 98 evaluable patients (7.1%) in the LMWH group and 9 of the 95 evaluable patients (9.5%) in the OA group had a documented recurrence of venous thromboembolism (Fisher ’s exact test, p = 0.61). Of these, 2 patients who received LMWH and 7 patients on acenocoumarol had recurrences in the 3-month period of secondary prophylaxis. Four patients (4.1%) in the LMWH group developed bleeding complications during this study period, as compared with 7 (7.4%) in the OA group (Fisher’s exact test, p = 0.37). There were two major bleedings, one in the LMWH group and one in the OA group. Eleven patients died, 5 (5.1%) in the LMWH group and 6 (6.3%) in the OA group. It is concluded that nadroparin in a dose of 85 anti-Xa IU/kg s.c. once daily provides an effective and safe alternative to oral anticoagulants in the secondary prophylaxis of DVT.
Immune Tolerance Therapy for Haemophilia A Patients with Acquired Factor VIII Alloantibodies: Comprehensive Analysis of Experience at a Single Institution
Authors: Spence K. J. , Waters E. L. , Beresford-Webb R. , Mitchell M. J. , Cuttler J. , Alhaq A. , Brown S. A. , Savidge G. F. , Smith M. P. 
Published: March 2018

SummaryEleven children with severe haemophilia A associated with the IVS 22 inversion and acquired high titre neutralising antibodies to factor VIII underwent immune tolerance induction. HLA class I and high resolution class II type is detailed for each patient. A three phase approach to immune tolerance induction was used. During phase 1, which lasted a median of six weeks, patients received factor VIII 100 IU/kg twice daily. Phase 2 comprised a factor VIII dose reduction to 100 IU/kg once daily, and continued for a median duration of 14 weeks. Subsequently 10 of the 11 patients satisfied the criteria of absent factor VIII neutralising activity by the Bethesda method, and a factor VIII elimination half life of greater than 5 h, allowing progression to phase 3, a further factor VIII dose reduction to 50 IU/kg three times weekly. A model for dose reduction as factor VIII tolerance evolves, based on pharmacokinetic analysis, is described.
Double Fluorescent-amplification Refractory Mutation Detection (dF-ARMS) of the Factor V Leiden and Prothrombin Mutations
Authors: Maher Caroline , Crowley Dolores , Cullen Carmel , Wall Carmel , Royston David , Fanning Séamus 
Published: March 2018

SummarySimultaneous fluorescent [F] detection of the factor V Leiden (G1691A) and the prothrombin 3’-untranslated region (G20210A) mutations were performed in a single tube polymerase chain reaction (PCR). Amplification refractory mutation detection system (ARMS) formed the basis of this assay design. Fluorescent-labelled primers incorporated into amplicons during the reaction facilitated detection directly by GeneScan analysis without further manipulation. To test the efficacy of this double [F]-ARMS (dF-ARMS) method, 48 patients with unexplained thrombotic tendencies were investigated for their factor V Leiden and prothrombin genotypes. These results corresponded exactly with data achieved using the more conventional methods of restriction fragment length polymorphism (RFLP)-PCR and direct DNA sequencing. Three out of the 48 patients in this group were found to be compound heterozygotes.
Plasmin-α2-antiplasmin Complex in Patients with Atrial Fibrillation
Authors: Feinberg William , Macy Elizabeth , Cornell Elaine , Nightingale Sarah , Pearce Lesly , Tracy Russell , Bovill Edwin ,   for the Stroke Prevention in Atrial Fibrillation Investigators
Published: March 2018

SummaryPlasmin-α2-antiplasmin complex (PAP) is an index of recent fibrinolytic activity. We examined PAP levels in patients with atrial fibrillation (AF) to determine whether these levels are correlated with clinical characteristics associated with stroke risk. We obtained blood for measurement of PAP in a non-random sample of 586 patients with AF on entering the Stroke Prevention in Atrial Fibrillation III Study. PAP levels were measured with an ELISA assay. PAP values were transformed with a natural logarithm (PAPln) prior to all analyses. Older age, female gender, recent congestive heart failure, decreasing fractional shortening, recent onset of AF, and coronary artery disease were each univariately associated with higher levels of PAP (all p <0.05, two-sample t-test, simple linear regression). Older age, recent congestive heart failure, decreasing fractional shortening, and recent onset of AF were independently associated with higher PAP levels by multivariate analysis (linear regression). Among patients receiving warfarin, PAP levels were not correlated with INR levels (linear regression, p = 0.60). Patients classified as high-risk for thromboembolism by our risk stratification criteria (systolic blood pressure >160 mm Hg, prior thromboembolism, recent congestive heart failure, poor left ventricular function, and women over age 75) had higher PAP levels than low-risk patients (antilog mean PAPln 5.6 vs 4.9, p <0.001, two-sample t-test). PAP levels in patients with AF are associated with clinical characteristics predictive of thromboembolism. Elevated PAP levels are particularly associated with poor left ventricular function and are not affected by anticoagulation. PAP levels may be a marker of stroke risk in patients with AF.Presented in part at the American Heart Association 22nd annual Joint Conference on Stroke and the Cerebral Circulation, Anaheim, CA, February, 1997.
Estimation of the von Willebrand Factor-cleaving Protease in Plasma Using Monoclonal Antibodies to vWF
Authors: Obert Bernadette , Tout Hélène , Veyradier Agnès , Fressinaud Edith , Meyer Dominique , Girma Jean-Pierre 
Published: March 2018

SummaryA protease present in plasma cleaves von Willebrand factor (vWF) at the peptide bond 842Tyr-843Met of the mature subunit. To quantify this vWF-cleaving protease activity in plasma we have developed a simple method based on the estimation by IRMA of the degradation of a constant amount of wild type recombinant vWF used as substrate, by serial dilutions of test plasma used as protease provider. vWFAg was estimated by two-site IRMA using as first coating antibody a monoclonal antibody (MoAb) whose epitope is localized on the C-terminal side of the cleavage site, and as second labeled antibody a pool of MoAbs specific for the N-terminal side. Because the proteolytic process leads to the progressive separation of the C- and N-terminal portions of the vWF subunit such an IRMA also shows a progressive apparent loss of vWFAg. In contrast, the levels of vWFAg estimated after proteolysis by regular IRMA remained essentially constant. Results obtained with this new method were compared with the analysis by SDS-agarose gel electrophoresis of the multimeric pattern of proteolyzed WT-rvWF and no significant difference was noted testing a series of 28 plasmas. As compared with normal pooled plasma, 14 normal individuals and 13 patients with various types of vWD had normal levels of protease activity (44-178%) by both methods. The validity of the method was confirmed by showing a lack of detectable protease activity in a patient with chronic relapsing thrombotic thrombocytopenic purpura. In conclusion our method appears as a useful tool for the quantification of the vWF-cleaving protease activity in plasma. Its sensitivity and specificity are similar to those of SDS-gel electrophoresis. However, this new IRMA has the major advantages of being much simpler and faster, and open to most research laboratories in the field.
The VITA Project: Prothrombin G20210A Mutation and Venous Thromboembolism in the General Population
Authors: Tosetto Alberto , Missiaglia Edoardo , Frezzato Maurizio , Rodeghiero Francesco 
Published: March 2018

SummaryRecently a new identified genetic variant in the 3’-untranslated region of the prothrombin gene (G20210A allele) associated with increased plasma prothrombin levels has been linked to an increased risk of venous thromboembolism (VTE). Most of our knowledge on the G20210A allele as a risk factor for VTE derives from a population-based case-control study and from studies on selected series of VTE patients. To determine the importance of the G20210A allele as a causative risk factor for VTE in the general population, we analyzed the cross-sectional data of the Vicenza Thrombophilia and Atherosclerosis (VITA) Project. One hundred sixteen cases of VTE, ascertained in a random fashion within the general population aged 18-65, were age and sex-matched with 232 healthy subjects. Heterozygosity for the G20210A allele was present in 4.3% of VTE cases and in 3.4% of controls, indicating a marginal increase of VTE risk in carriers of the allele (odds ratio: 1.26; 95% CI 0.4-3.9). However, the VTE risk was substantially higher in subjects with idiopathic VTE before age 45 or with recurrent, idiopathic VTE (odds ratio: 2.8; 95% CI 0.6-13.8) or in subjects with a family history of VTE (odds ratio: 7.6; 95% CI 1.8-32.8). Accordingly, our results suggest that the G20210A allele associates with VTE only in selected cases, and that screening for this genetic variant is not warranted for all patients with VTE.