bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunochemical Detection of the Thomsen-Friedenreich Antigen (T-Antigen) on Platelet Plasma Membranes
Authors: Glöckner Wolfgang M , Kaulen Hermann D , Uhlenbruck Gerhard 
Published: July 2018

SummaryPlatelet plasma membranes were found to possess the disaccharide β--galactosyl(1−3)-N-acetyl-D-galactosamine which was measured by gas chromatography after release by alkaline borohydride treatment and desialylation. Immunological evidence using the specific lectins from Arachis hypogoea and Agaricus bisporus and an anti-T serum confirmed the presence of this disaccharide, the immunodominant group of the Thomsen-Friedenreich antigen (T-antigen). This receptor was only found after prior neuraminidase treatment indicating that it is normally a cryptic antigen, i.e. masked by sialic acid in the native membrane. Evidence for a second receptor with terminal N-acetylgalactosamine was obtained using the lectin from Helix pomatia. The binding of myxovirus and the lectins from Phaseolus vulgaris (PHA) and Canavalia ensiformis (Con A) to platelet membrane was also demonstrated.The implication of the T-antigen in elimination of the platelets and its role in the haemolytic-uraemic syndrome is discussed.
Antibody-Induced Acute Factor X Deficiency: Clinical Manifestations and Properties of the Antibody
Authors: Vijaya Mohan Rao L , Zivelin Ariella , Iturbe Ignacio , Rapaport Samuel I 
Published: July 2018

SummaryA patient is described with serious bleeding due to a transient selective deficiency of factor X. Crossed immunoelectrophoresis of patient’s plasma with anti-factor X antibody revealed an abnormal factor X arc suggestive of the presence of plasma factor X/anti-factor X immune complexes. A similar abnormal arc was obtained on adding the patient’s IgG to normal plasma. Immunoblotting of factor X after reduced SDS-PAGE revealed that the patient’s IgG bound to the light chain of intact factor X but not Gla-domainless factor X. The patient’s IgG inhibited activation of factor X by Vila/tissue factor (TF), by IXa/VIIIa/phospholipid complex, and by Russell’s viper venom. The IgG failed to inhibit the proteolytic activity of factor Xa towards a chromogenic substrate. However, under reaction conditions of limited factor Xa availability, the IgG could be shown to impair hemostatic functions of factor Xa that require the participation of its light chain: activation of prothrombin by prothrombinase; activation of factor VII bound to TF; and inhibition of VIIa/TF activity by factor Xa/tissue factor pathway inhibitor complexes. A few earlier patients have been described with transient, selective factor X deficiency and serious bleeding, but in only one was evidence obtained of an antibody against factor X. It will be of interest to learn whether use of the techniques described in this report will permit the identification of immunoglobulin with similar binding and functional properties in future patients with this rare syndrome.
Inhibition of Platelet Recruitment to Arterial Lesions by Predeposition of Platelets Containing Encapsulated lloprost
Authors: Pfliegler George , El-Gamal Basiouny , José Badimon Juan , Badimon Lina , Crawford Neville 
Published: July 2018

SummaryDrugs can be encapsulated within blood platelets by reversible electroporation and can be haemostatically targeted to vessel wall injury sites. Initial studies with iloprost-loaded pig platelets and pig aorta tunica media in perfusion circuits are presented. After autologous reconstitution into blood, no significant difference was observed in the deposition of 111Indium labelled sham-loaded and untreated platelets onto the tunica media during perfusion under low and high shear conditions. In paired experiments (n = 10 pairs), the deposition of iloprost-loaded platelets was significantly lower (mean 61%) after 5 min perfusion than the deposition from blood containing sham-loaded (control) platelets. A similar significant reduction (mean 54%) was seen after 10 min perfusion. Pre-perfusion of iloprost-loaded platelets for 10 min under low shear conditions (212/s), followed by 5 min perfusion of 111Indium labelled normal platelets, significantly reduced the secondary platelet deposition (p <0.01) when compared with the deposition seen when control untreated platelets were preperfused. Significant differences (p <0.001) in secondary deposition were also observed when primary and secondary platelet perfusions were made under high shear (1690/s).Histology of the tunica media segments post perfusion, supported the inhibitory effect of predeposited iloprost-loaded platelets on secondary platelet recruitment. By exploiting their natural haemostatic propensity, drug-loaded platelets can be targeted to vessel wall injury sites. Appropriate drugs could be packaged that may passivate the carrier platelets at the lesion inhibiting thrombus formation or they may act as a depot for sustained drug release. This platelet drug delivery strategy may have application in the prevention of the thrombotic and reste-notic events that can occur post angioplasty, or following therapy with thrombolytics, or after more invasive surgical procedures involving vascular reconstruction or prosthetic implantation.
Evaluation of a Soluble Fibrin Assay in Patients with Suspected Deep Vein Thrombosis
Authors: Ginsberg Jeffrey S , Siragusa Sergio , Douketis James , Johnston Marilyn , Moffat Karen , Stevens Pamela , Brill-Edwards Patrick , Panju Akbar , Patel Ameen 
Published: July 2018

SummaryBackground. The objective of this study was to determine the clinical utility of an enzyme immunoassay (HIA) for soluble fibrin in patients with clinically suspected deep vein thrombosis (DVT).Methods and Results. 101 unselected patients with clinically suspected DVT underwent blood sampling for measurement of plasma levels of soluble fibrin, and objective testing for DVT. According to results of the objective tests, patients were classified as DVT-positive (n = 34) or DVT-negative (n = 67). Using different cut-points of soluble fibrin results, the sensitivities, specificities, positive and negative predictive values of the soluble fibrin assay were calculated. A soluble fibrin result of ≤0.75 mg/ml showed a sensitivity and negative predictive value of 100%, and a specificity of 17.9% for DVT, a soluble fibrin result of ≤ 1.40 mg/ml showed a sensitivity of 91.2% and a negative predictive value of 93.6%, and a specificity of 65.7% for DVT, whereas a soluble fibrin result of ≤ 8.0 mg/ml showed a specificity and positive predicive value of 100% for DVT.Conclusions. This study demonstrates that the soluble fibrin assay used in the study has potential clinical utility as a diagnostic test in patients with clinically suspected DVT and supports further evaluation of this assay.
Effect of Fibrinogen Substitution in Afibrinogenemia on Hemorheology and Platelet Function
Authors: Reininger Armin J , Reininger Cornelia B , Spannagl Michael , Mellinghoff Achim , Porr Astrid , Heinzmann Ulrich , Wurzinger Laurenz J 
Published: July 2018

SummaryFibrinogen substitution can correct bleeding in afibrinogenemia. We assessed the effect of fibrinogen substitution in a patient lacking immunoreactive fibrinogen. Fibrinogen and thrombin time were not measurable before, but became detectable within 30 min after substitution, parallelled by an increase in ADP-induced platelet aggregation from <10% to 32%. Platelet adhesion, measured by Stagnation Point Flow Adhesio- Aggregometry, was notdetectable prior to substitution but attained normal values thereafter. Scanning electron microscopy of adhering platelets revealed pseudopodia protrusion and spreading. Morphometry revealed two populations of spread platelets one of which demonstrated inhibited spreading as compared to healthy controls. Immunoelectron microscopy revealed normal GPIIb/IIIa receptor expression, both before and after substitution. Dynamic and kinematic viscosity of plasma and whole blood remained below the 99.9% confidence border of a healthy control group. In afibrinogenemia fibrinogen levels as low as 10% of normal concentration sufficed to normalize coagulation, platelet adhesion, and, partially, spreading.
Effects of 6-[p-(4-Phenylacetylpiperazin-l-yl)-phenyl]-4,5-Dihydro-3(2H)-Pyridazinone (CCI 17810) and Aspirin on Experimental Arterial Thrombosis in Rats
Authors: Lecker Dorothy , Kumar Abhilash 
Published: July 2018

SummaryAn experimental model for arterial thrombosis has been investigated in rats. A loop of polythene tubing inserted in the left carotid artery induced thrombus formation on the arterial wall at the points of contact with the tips of the cannula. Sprague Dawley (CFY) rats were more susceptible to the thrombotic stimulus than were Wistar (WAG) rats. Whole blood platelet adhesiveness measured by a glass bead column method was higher in CFY rats than in WAG rats.6 - [p - (4-Phenylacetylpiperazin-1 - yl) - phenyl] - 4,5 - dihydro-3(2H)-pyridazinone (CCI 17810) inhibited thrombus formation in CFY rats. Both the incidence of occlusion of the cannulated artery and the mean thrombus weight were reduced by CCI 17810 in doses of 25, 50 or 100 mg/kg administered orally twice daily; the effects were dose-related.The effects of aspirin depended on the dose administered. A high dose (200 mg/kg) did not inhibit thrombus formation whereas a low dose (20 mg/kg) reduced the incidence of occlusion and the mean thrombus weight. These results are in accord with the differential effects of aspirin on platelet and blood vessel wall cyclooxygenase.
Disseminated Intravascular Coagulation Is a Frequent Complication of Systemic Inflammatory Response Syndrome
Authors: Gando Satoshi , Kameue Takashi , Nanzaki Satoshi , Nakanishi Yoshimi 
Published: July 2018

SummaryTo evaluate the role of disseminated intravascular coagulation (DIC) and to determine the influence of antithrombin, protein C, and plasminogen activator inhibitor 1 on multiple organ dysfunction syndrome (MODS) and outcome in patients with systemic inflammatory response syndrome (SIRS), we made a prospective cohort study. The study subjects consisted of thirty-five patients who exhibited two or more of the conditions of SIRS for more than three consecutive days. They were classified into subgroups of survivors (n = 13) and nonsurvivors (n = 22). The global coagulation and fibrinolytic markers, antithrombin, protein C, and plasminogen activator inhibitor 1 were measured on the day of the diagnosis of SIRS, and also on the 1st, 3rd, and 5th days. The results of these measurements, demographic data, criteria of severity, incidence of MODS were compared between the subgroups. For prediction of patient’s death, a receiver operating characteristic (ROC) curve analysis was made. DIC was frequently associated with SIRS patients (29/35, 82.9%). A significant decrease in the DIC score was found in the survivors (p = 0.0001). None of them suffered from DIC on the 5th day. In the nonsurvivors, low levels of protein C and antithrombin and markedly high values of plasminogen activator inhibitor 1 continued up to the 5th day, no improvement of the DIC was observed during the study period and the number of the dysfunctioning organs were significantly higher than in the survivors. Plasminogen activator inhibitor 1 on the 5th day had prognostic value for the prediction of death on the SIRS patients. In conclusion, DIC occurs commonly in patients with SIRS and may be the main determinant for the outcome of these patients. Changes in antithrombin, protein C, and plasminogen activator inhibitor 1 are one of the aggravating factors of MODS. Furthermore, plasminogen activator inhibitor 1 is a good predictor of death in these patients.
Distribution and Occlusiveness of Thrombi in Patients with Surveillance Detected Deep Vein Thrombosis after Hip Surgery
Authors: Ascani Alessandra , Radicchia Stefano , Parise Pasquale , Nencl Giuseppe G , Angelli Giancarlo 
Published: July 2018

SummaryVenous thromboembolism is a leading cause of in-hospital postoperative morbidity and mortality. Postoperative deep vein thrombosis (DVT) is usually asymptomatic. A number of studies have consistently shown that the non invasive diagnostic methods are inaccurate in the screening of asymptomatic DVT. Failure of non invasive diagnostic methods to detect thrombi in asymptomatic patients has been suggested to be due to the features of thrombi in these patients. The aim of this study was to assess the distribution and the occlusiveness of thrombi in a series of 321 asymptomatic hip surgery patients with adequate bilateral venography of the lower limbs.Venography was performed 10 ± 1 days after hip surgery. DVT was found in 180 limbs (28.0%). The distribution of thrombi was as follows: 26 (14.4%) isolated proximal thrombi, 55 (30.6%) proximal and distal thrombi, 99 (55.0%) isolated calf thrombi. We found that 14 of the 81 proximal trombi (17.3%) involved the superficial femoral vein either as exclusive location or in association with calf veins. An involvement of common femoral, superficial femoral and popliteal vein was observed in 37 (45.7%), 39 (48.1%) and 44 (54.3%) cases of the 91 proximal DVT. These thrombi were non occlusive in 25 (67.6%), 22 (56.4%) and 26 (59.1%) limbs, respectively. An involvement of at least one peroneal, anterior tibial and posterior tibial veins was observed in 118,13 and 89 cases of the 220 distal thrombi. These thrombi were non occlusive in 61 (51.7%), 10 (76.9%) and 30 (33.7%) of the cases.We conclude that the majority of thrombi found in asymptomatic hip surgery patients are non occlusive. In view of this, non invasive diagnostic methods based upon venous flow measurement will be unlikely to improve the diagnosis of asymptomatic DVT. The high incidence of isolated superficial femoral vein thrombosis necessitates that real-time B-mode ultrasonography should be performed examining the entire proximal venous system.
Platelet-Associated Anti-Glycoprotein (GP) IIb-IIIa Autoantibodies in Chronic Immune Thrombocytopenic Purpura Mainly Recognize Cation-Dependent Conformations: Comparison with the Epitopes of Serum Autoantibodies
Authors: Kosugi Satoru , Tomiyama Yoshiaki , Shiraga Masamichi , Kashiwagi Hirokazu , Mizutani Hajime , Kanakura Yuzuru , Kurata Yoshlyuki , Matsuzawa Yuji 
Published: July 2018

SummaryPlatelet-associated and serum anti-glycoprotein (GP) IIb-IIIa autoantibodies were investigated in 57 patients with chronic immune thrombocytopenic purpura (ITP). In modified antigen capture ELISA (MACE) using GPIIb-IIIa-specific-, GPIIb-specific-, and GPIIIa-speci-fic-monoclonal antibody (mAb) for antigen capture, platelet-associated anti-GPIIb-IIIa antibodies were detected in 14 out of 37 patients (38%), and these antibodies could be detected with all 3 mAbs used for antigen capture. In the MACE using EDTA-treated platelets at 37° C, the reactivity of platelet-associated anti-GPIIb-IIIa antibodies in 9 out of 10 patients was markedly reduced in both cases of GPIIb-specific- and GPIIIa-specific-mAb used. Immunoprecipitation experiments further confirmed that the EDTA-treatment abrogated the antigenicity of GPIIb-IIIa for platelet-associated antibodies in 2 patients. Serum anti-GPIIb-IIIa autoantibodies were detected in 23 out of 57 patients (40%). However, only 7 out of 23 serum anti-GPIIb-IIIa antibodies could be detected with all 3 mAbs. The MACE using EDTA-treated platelets further showed that the features of serum anti-GPIIb-IIIa antibodies were different from those of platelet-associated antibodies even in the same patient. Our data demonstrate that the platelet-associated anti-GPIIb-IIIa antibodies mainly recognize the cation-dependent antigenic determinants on GPIIb-IIIa and that serum anti-GPIIb-IIIa antibodies may contain some components which differ in specificity from platelet-associated antibodies.
UHG-based Mutation Screening in Type 2B von Willebrand’s Disease: Detection of a Candidate Mutation Ser547Phe
Authors: Wood Nigel , Standen Graham R , Bowen Derrick J , Cumming Anthony , Lush Christopher , Lee Richard , Bidwell Jeffery 
Published: July 2018

SummaryWe have recently described a novel mutation screening technique for the diagnosis of type 2B von Willebrand’s disease (vWD). Analysis involves the use of a synthetic universal heteroduplex generator (UHG). To test the validity of the technique, we have applied UHG screening to seven type 2B vWD patients of previously unknown genotype. Characteristic heteroduplex patterns for Arg543Trp and Val553Met mutations were found in three patients and one patient, respectively. A fifth patient gave a novel pattern and direct sequencing revealed a hitherto unreported candidate mutation (Ser547Phe) 8 bases downstream of an “identifier” deletion in the UHG molecule. The two remaining patients gave normal heteroduplex patterns; an Arg578Gln mutation was identified by PstI digestion in one individual and no mutation could be identified in the sequence covered by the UHG in the final patient. Using a combination of UHG technology and restriction analysis, over 85% of type 2B vWD patients can be rapidly diagnosed by genotype.
Effects on Haemostasis of Hormone Replacement Therapy with Transdermal Estradiol and Oral Sequential Medroxyprogesterone Acetate: A 1 -year, Double-blind, Placebo-controlled Study
Authors:   The Writing Group for the Estradiol Clotting Factors Study
Published: July 2018

SummaryAfter menopause the haemostatic balance shifts towards a latent hypercoagulable state. To evaluate the effects of two regimens of transdermal estradiol (E2) combined with progestin on the balance between procoagulant factors and inhibitors, 255 women in physiological menopause for 1-5 years were randomly allocated to 1 year of treatment with cyclic transdermal E2 (50 Μg/day for 21 days) plus medroxyprogesterone acetate (MPA) (10 mg/day from days 10 to 21), continuous transdermal E2 (50 Μg/day for 28 days) plus MPA (10 mg/day from days 14 to 25), or placebo. Fibrinogen, factor VII (FVII), factor VIII:C (FVIII:C), antithrombin III (ATIII), protein C, protein S, heparin cofactor II (HCII) and plasminogen activator inhibitor (PAI-1) levels were measured at baseline and after 6 and 12 cycles. 167 women who took the treatment for at least 6 cycles were evaluable. The continuous treatment group had significantly lower final values of fibrinogen, FVII, ATIII, protein S and HCII than the placebo group; the cyclic treatment reduced fibrinogen in comparison with placebo but the difference was not significant.In conclusion, both regimens produce a clinically relevant decrease of fibrinogen levels; the continuous regimen affects also the levels of FVII and inhibitors suggesting that the haemostatic balance is shifted to a more physiological state.
Role of the A+ Helix in Heparin Binding to Protein C Inhibitor
Authors: Elisen Marc G L M , Maseland Machiel H H , Church Frank C , Bouma Bonno N , Meijers Joost C M 
Published: July 2018

SummaryInteractions between proteins and heparin(-like) structures involve electrostatic forces and structural features. Based on charge distributions in the linear sequence of protein C inhibitor (PCI), two positively charged regions of PCI were proposed as possible candidates for this interaction. The first region, the A+ helix, is located at the N-terminus (residues 1-11), whereas the second region, the H helix, is positioned between residues 264 and 280 of PCI. Competition experiments with synthetic peptides based on the sequence of these regions demonstrated that the H helix has the highest affinity for heparin. In contrast to previous observations we found that the A+ helix peptide competed for the interaction of PCI with heparin, but its affinity was much lower than that of the H helix peptide.Recombinant PCI was also used to investigate the role of the A+ helix in heparin binding. Full-length (wild-type) rPCI as well as an A+ helix deletion mutant of PCI (rPCI-Δ2-l 1) were expressed in baby hamster kidney cells and both had normal inhibition activity with activated protein C and thrombin. The interaction of the recombinant PCIs with heparin was investigated and compared to plasma PCI. The A+ helix deletion mutant showed a decreased affinity for heparin in inhibition reactions with activated protein C and thrombin, but had similar association constants compared to wild-type rPCI. The synthetic A+ helix peptide competed with rPCI-Δ2-11 for binding to heparin. This indicated that the interaction between PCI and heparin is fairly non-specific and that the interaction is primarily based on electrostatic interactions.In summary, our data suggest that the H helix of PCI is the main heparin binding region of PCI, but the A+ helix increases the overall affinity for the PCI-heparin interaction by contributing a second positively charged region to the surface of PCI.
Ablation Characteristics of Arterial Vessel Walls Irradiated with the Pulsed Dye Laser - An Analysis of Variance
Authors: Arndt Volker R , Duda Stephan H , Wehrmann Manfred , Huppert Peter E , Haase Konstantin K , Claussen Claus D 
Published: July 2018

Summary
Background and Objective: Since most clinical laser angioplasties require the use of over-the-wire delivery systems, we studied the effects of pulsed dye laser energy (504 nm, 1.4 μs) on arterial vessel walls in combination with a multifiber catheter system.
Material and Methods: Postmortem arterial segments (n = 368) were exposed under blood or saline. Laser pulses (n = 100-800) were transmitted via 9F-multifiber-catheters, at energy densities of 3-16 J/cm2. Ablation characteristics revealed by histologic examination and morphometry were analyzed by multiple analysis of variance.
Results: Ablation occurred more frequently in saline compared to blood. Below an energy density of 10 J/cm2 ablation occurred in saline only. Specimens irradiated under blood showed only thermal changes at 10 J/cm2. In saline, 92% of normal, 88% of fibro-fatty and 60% of calcified tissue showed ablation at 13 J/cm2. The average ablation threshold in saline was about 3-4 J/cm2 per pulse for normal tissue, 5 J/cm2 for fatty plaques, and 8-9 J/cm2 for calcified plaques. In blood, the average ablation thresholds did not differ significantly between the different stages of arteriosclerosis (12 J/cm2 for normal tissue, 11 J/cm2 for fatty plaque, and 10 J/cm2 for calcified tissue). Carbonization and vacuolization were seen regularly at energy levels ≥13.4 J/cm2.
Conclusions: Selective ablation of arteriosclerotic tissue with the pulsed dye laser could not be found. Further investigation is needed before an effective ablation of arteriosclerotic arterial tissue can be expected.
Activation of Factor X by Factor VIIa Complexed with Human-mouse Tissue Factor Chimeras Requires Human Exon 3
Authors: Fang Carrie H , Lin T-C , Guha Arabinda , Nemerson Yale , Konigsberg William H 
Published: July 2018

SummaryIn an attempt to define sequence elements in human and mouse tissue factor (TF) that are responsible for the species specificity observed in their interaction with human factor VIIa (HVIIa), we constructed human-mouse chimeric TF cDNAs, inserted them into plasmid vectors, and induced their expression in E.coli. Assays for procoagulant activity were carried out with the resulting E. coli lysates using (HVIIa) human and mouse (MVIIa). The ratio of the procoagulant activities, HVIIa/MVIIa, revealed that human TF exon 3 was essential for activity when the TF:VIIa complex was formed with HVIIa. By ligating the maltose binding protein (MBP) gene to TF cDNAs it was possible to construct, express and purify MBP-TF chimeras as well as to estimate their specific activities. With selected MBP-TF chimeras and HVIIa we determined kinetic parameters for the activation of human factor X. Replacement of exon 3 in human TF cDNA with the corresponding exon from mouse TF cDNA resulted in both lower affinity for HVIIa and failure to convert bound HVIIa into a potent protease