bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellular Localization of Activated Factor X by Xa-Specific Probes
Authors: Zacharski Leo R , Dunwiddie Christopher , Nutt Elka M , Hunt Jane , Memoli Vincent A
Published: July 2018

A probe, recombinant antistasin, that reacts specifically with the activated form of factor X (Xa) was used in immunohistochemical procedures to detect cellular sites of Xa generation within intact tissues. Factor Xa was detected on tumor cells in small cell carcinoma of the lung, renal cell carcinoma, and malignant melanoma. Tumor-associated macrophages (but not tumor cells) expressed Xa in adenocarcinoma and squamous cell carcinoma of the lung, and Hodgkin’s disease. Factor Xa in these locations corresponded to evidence reported previously for an intact coagulation pathway and thrombin formation associated with these tumor cells and macrophages. By contrast, only rare connective tissue cells stained for Xa in breast and colon cancer, tumor types shown previously to lack an intratumoral coagulation pathway and thrombin generation, and in normal liver, lung, breast, kidney, and placental tissues. Hepatocytes did not stain. These results suggest that such probes may be useful for studying the activation state of cell-associated factor X in situ within intact tissues.
Baboon Fibrinogen Adsorption and Platelet Adhesion to Polymeric Materials
Authors: Chinn Joseph A , Horbett Thomas A , Ratner Buddy D
Published: July 2018

The role of fibrinogen in mediating platelet adhesion to polymers exposed to blood plasma was studied by comparison of the effect of plasma dilution on fibrinogen adsorption and platelet adhesion, and by the use of coagulation factor deficient plasmas. Polyetherurethane substrates were first preadsorbed with dilute plasma, then contacted with washed platelets suspended in a modified, apyrase containing Tyrode’s buffer. Platelet adhesion was studied under static conditions in Multiwell dishes, and also under shearing conditions using a parallel plate perfusion chamber. Fibrinogen adsorption and platelet adhesion were measured using 125I radiolabeled baboon fibrinogen and min radiolabeled baboon platelets, respectively. Surfaces were characterized by electron spectroscopy for chemical analysis (ESCA).

When fibrinogen adsorption to Biomer was measured after 2 h contact with a series of dilute plasma solutions under static conditions, a peak in adsorption was observed from 0.26% plasma, i.e., adsorption was greater from 0.26% plasma than from either more or less dilute plasma. A peak in subsequent platelet adhesion to the plasma preadsorbed surfaces, measured after 2 h static incubation with washed platelets, was also observed but occurred on Biomer preadsorbed with 1.0% plasma.

When fibrinogen adsorption was measured after 5 min contact under shearing conditions, the fibrinogen adsorption peak occurred on surfaces that had been exposed to 1.0% plasma. A peak in platelet adhesion to these preadsorbed surfaces, measured after 5 min contact with the platelet suspensions under shearing conditions, was observed on Biomer preadsorbed with 0.1% plasma. Shifts between the positions of the peaks in protein adsorption and platelet adhesion occurred on other polymers tested as well.

Platelet adhesion was almost completely inhibited when baboon and human plasmas lacking fibrinogen (i. e., serum, heat defibrinogenated plasma, and congenitally afibrinogénémie plasma) were used. Platelet adhesion was restored to near normal when exogenous fibrinogen was added to fibrinogen deficient plasmas. Adhesion was also inhibited completely when a monoclonal antibody directed against the glycoprotein IIb/IIIa complex was added to the platelet suspension. Platelet adhesion to surfaces preadsorbed to von Willebrand factor deficient plasma was the same as to surfaces preadsorbed with normal plasma.

While it appears that surface bound fibrinogen does mediate the initial attachment of platelets to Biomer, the observation that the fibrinogen adsorption and platelet adhesion maxima do not coincide exactly also suggests that the degree of subsequent platelet adhesion is dictated not only by the amount of surface bound fibrinogen but also by its conformation.
Recommendations for the Evaluation and Treatment of Neonatal Autoimmune and Alloimmune Thrombocytopenia
Authors: Bussel J , Kaplan C , McFarland J ,   Working Party on Neonatal Immune Thrombocytopenia of the Neonatal Hemostasis Subcommittee of the Scientific and Standardization Committee of the ISTH
Published: July 2018

The following recommendations of the Neonatal Hemostasis Subcommittee of the Scientific and Standardization Committee of the ISTH for the management of neonatal immune thrombocytopenia were prepared by the working party on neonatal immune thrombocytopenia. Evaluation, diagnosis, and treatment of the mother and neonate with alloimmune and autoimmune thrombocytopenia are discussed and current recommendations provided. This document is likely to require frequent future revision(s).
Reconstrucción de pene luego de necrosis de glande por priapismo
Authors: Gaviria Gil Federico , Benavides Johana , Lopera Adrián
Published: July 2018

Introducción El priapismo se define como una erección parcial o completa que dura más de 4 horas en ausencia de estímulo sexual. Se clasifica en isquémico, no isquémico e intermitente. El primero corresponde a la mayoría de casos y puede producirse por un estímulo sexual o por medicamentos. El manejo inicial consiste en la aspiración de los cuerpos cavernosos y la inyección de simpaticomiméticos. Cuando esas medidas fallan, el manejo quirúrgico está indicado. Entre las complicaciones más frecuentes está la disfunción eréctil, sin embargo, en la literatura, hay muy pocos reportes de necrosis de pene.

Descripción del Caso Clínico Paciente de 60 años de edad que presentó priapismo isquémico luego de la inyección intracavernosa de prostaglandina E. Viene a consulta y le realizan lavado de cuerpos cavernosos con inyección de simpaticomiméticos que no fue exitoso; por lo que le realizan fístula espongio-cavernosa distal (Al-Ghorab) y rafia de uretra por lesión advertida. Consulta nuevamente por persistencia de edema, áreas necróticas y sangrado en glande. Se decidió iniciar manejo médico. Presentó evolución estacionaria y aumento en necrosis por lo que se derivó con cistostomía y se realizó desbridamiento de tejido necrótico inicialmente. Posteriormente se realizó Reconstrucción peneana + Uretroplastia peneana + Lavado desbridamiento de tejidos + Cistoscopia con buena evolución clínica.

Conclusiones Existen diferentes factores de riesgo para presentar priapismo de origen isquémico como es la inyección de medicamentos intracavernosos. La principal complicación que se presenta es la disfunción eréctil. Sin embargo, hay pocos casos descritos de necrosis de glande. En el caso de nuestro paciente se plantean diferentes hipótesis como factores contribuyentes a la necrosis como son el uso de simpaticomiméticos y/o la desvascularización del glande posterior a la cirugía. Al enfocar ese tipo de paciente, es indispensable realizar un adecuado manejo inicial para prevenir ese tipo de complicación que, aunque es poco frecuente, puede resultar catastrófica.
Linfoma tipo Burkitt, un inusual subtipo de linfoma testicular no Hodgkin en el adulto: reporte de un caso y revisión de la literatura
Authors: Cerquera Cleves Diana , Donoso Donoso Wilfredo
Published: July 2018

Objetivo Realizar el reporte de un caso de linfoma testicular no Hodgkin tipo Burkitt, presentando una revisión de la literatura y documentando las variaciones histológicas típicas, los métodos diagnósticos, el impacto del manejo inicial y el abordaje de las metástasis e infiltraciones tumorales en el pronóstico de esa patología oncológica.

Metodología Se describe el caso de un hombre de 36 años en quien se diagnosticó un linfoma testicular tipo Burkitt, durante el estudio de un síndrome proliferativo, que inició con signos y síntomas neurológicos conllevando a la extensión del estudio y demostrando múltiples lesiones metastásicas asociadas a la infiltración del sistema nervioso central. El tratamiento incluye múltiples modalidades entre las que se encuentra la quimioterapia, radioterapia local, profilaxis intratecal entre otras; sin embargo, el pilar del manejo del compromiso testicular sigue siendo el quirúrgico.

Conclusión El linfoma testicular no hodking es una patología rara, siendo aún más infrecuente el subtipo Burkitt, a pesar del pobre pronóstico, el diagnóstico oportuno y el desarrollo de nuevas terapias aplicadas en combinación, han permitido mejorar la sobrevida y disminuir el riesgo de recaída y progresión.
The Role of Venom Haemorrhagin in Spontaneous Bleeding in Bothrops jararaca Envenoming
Authors: Kamiguti A S , Rugman F P , Theakston R D G , Franca F O S , Ishii H , Hay C R M ,   BIASG
Published: July 2018

Thirty-eight patients bitten by Bothrops jararaca were investigated. Twenty-six had signs of local or systemic haemorrhage. Twenty-two of these had incoagulable blood, and these patients were found to have low fibrinogen levels (mean 0.17 ± 0.03 g/1), thrombocytopenia, very high thrombin-antithrombin III complex (850 ± 184 pg/1) and D-dimer (170 ± 44 μg/ml) antigen levels. Serum venom haemorrhagin levels were significantly higher in patients with clinical signs of haemorrhage (36.4 ± 6.4 ng/ml) than those without (11.7 ± 3.7 ng/ml; p <0.002). Twelve out of 13 patients with thrombocytopenia were bleeding. High levels of thrombomodulin (22.3 ± 1.5 ng/ml) and haemorrhagin (35.7 ± 7.7 ng/ml) were detected in these 12 patients, suggesting vascular endothelial damage. Haemorrhagin levels also correlated inversely with platelet count in these patients. It was concluded that thrombocytopenia is one of the main causes of bleeding inB. jararaca victims, possibly as a result of venom haemorrhagin activity.
Homozygous Antithrombin Deficiency: Report of Two New Cases (99 Leu to Phe) Associated with Arterial and Venous Thrombosis
Authors: Chowdhury V , Lane D A , Mille B , Auberger K , Gandenberger-Bachem S , Pabinger I , Olds R J , Thein S L
Published: July 2018

Inherited antithrombin deficiency is associated with an increased risk of thrombosis, primarily venous rather than arterial. Most affected individuals have inherited only a single copy of an abnormal antithrombin (AT) gene. Homozygously affected individuals, although rare, have a severe thrombotic history of early onset and often affecting the arteries. We report two new cases of type II HBS (heparin binding site) deficiency in which the propositi are homozygous for the previously reported mutation 99 Leu to Phe, and who have a severe thrombotic history. These cases are considered alongside existing homozygote and compound heterozygote cases.
Hereditary Protein C Deficiency Associated with Mutations in Exon IX of the Protein C Gene
Authors: Doig R G , Begley C G , McGrath K M
Published: July 2018

This report describes five families with symptomatic hereditary protein C deficiency. Using a polymerase chain reaction (PCR)-based method, the entire coding sequence and intron-exon boundaries of the protein C gene was amplified from genomic DNA. In each family a single point mutation in the protein C gene was identified. Two unrelated families were found to share the same mutation, while the other three had different mutations. In the first two families with type I protein C deficiency the normal cytosine residue at nucleotide position 8551 in the protein C gene was replaced by thymidine leading to substitution of the normal proline residue at amino acid position 279 by leucine. In the third family with type I deficiency a previously undescribed mutation was identified. In this family the guanosine residue at position 8559 was replaced by adenosine (glycine 282 substituted by serine). In the fourth family, also with type I deficiency, guanosine 8589 was replaced by adenosine (glycine 292 substituted by serine). The fifth family had type II deficiency and in affected members cytosine 8769 was replaced by thymidine (arginine 352 substituted by tryptophan). All these mutations lead to amino acid substitutions in the serine protease domain of the mature protein. All were able to be confirmed by restriction enzyme analysis of PCR-derived DNA. In addition the novel mutation at nucleotide position 8559 was also demonstrable using single strand conformation polymorphism (SSCP) analysis of PCR-derived DNA. These mutations were likely examples of deamination of methylated cytosine occurring in cytosine-phosphate-guanosine (CpG) dinucleotide sequences. These findings confirm the genetic heterogeneity of hereditary protein C deficiency in these families.
CD4+ Counts before and after Switching to Monoclonal High-Purity Factor VIII Concentrate in HIV-Infected Haemophilic Patients
Authors: Sabin Caroline , Pasi John , Phillips Andrew , Elford Jonathan , Janossy George , Lee Christine
Published: July 2018

Allogenic proteins that contaminate intermediate purity clotting factor concentrates may activate the immune system of HIV-infected haemophilic patients. In 37 haemophilic patients infected with HIV who had originally been treated with intermediate purity factor VIII concentrate and then changed to monoclonally-purified high purity factor VIII concentrate the rates of CD4+ decline (109/1 per year) were 0.06 before and 0.02 after a switch to high purity products (p = 0.01). The median follow-up of patients after the switch to high purity products was 1.7 years (range 0.2 to 3 years). This significant change in the rate of CD4 decline was independent of the starting CD4 count, age and antiretroviral therapy. This result is consistent with those from randomised trials of the introduction of high-purity concentrate. Given the strong association between the CD4+ count and survival, treatment with high purity rather than intermediate purity clotting factor concentrate may confer a survival benefit for HIV-infected haemophilic patients.
Displacement of Fibrin-bound Thrombin by r-Hirudin Precludes the Use of 131l-r-Hirudin for Detecting Pulmonary Emboli in the Rabbit
Authors: Rubens Fraser D , Ross-Ouellet Bonnie , Dennie Carole , Coates Geoffrey , Kinlough-Rathbone Raelene L , Hatton Mark W C
Published: July 2018

Pulmonary emboli are detectable by filling defects in the pulmonary vasculature upon pulmonary angiography. Emboli derived from venous thrombi are rich in fibrin to which thrombin remains bound. Hirudin, a specific thrombin inhibitor, binds to thrombin to yield a 1:1 stoichiometric complex. We examined whether 131I-recombinant hirudin (r-hirudin) could be used to detect pulmonary emboli in rabbits. Clots were formed by re-calcifying rabbit plasma in vitro, and then injected (0.034 ml) into a femoral vein to lodge in the lungs. 131I-r-hirudin (29 ± 4 μCi/kg) was injected intravenously but emboli could not be detected by gamma camera in real time. Post-mortem analysis of lung tissue showed that 131I-r-hirudin did not associate with emboli prepared with 125I-fibrin. Because of these findings, we used different techniques to look at the binding of hirudin to plasma clots. Clots formed in vitro were incubated with 131I-r-hirudin in the presence of equimolar amounts of 125I-albumin; specific binding of 131I-r-hirudin was not observed. Experiments with immobilized fibrin(ogen) showed that 125I-r-hirudin did not bind to and remain with fibrin-bound 131I-thrombin but did lead to the inactivation and displacement of up to 70% of bound thrombin as r-hirudin-thrombin complex; residual thrombin bound to fibrin remained active. Thus, released r-hirudin-thrombin complex is probably cleared rapidly from the region of the embolus in vivo; radioiodinated r-hirudin may not, therefore, be useful as a marker for detecting emboli.
Relation of Plasma Coagulation Factor VII and Fibrinogen to Carotid Artery Intima-Media Thickness
Authors: Sosef M N , Bosch J G , van Oostayen J , Visser T , Reiber J H C , Rosendaal F R
Published: July 2018

Plasma clotting factor VII and plasma fibrinogen have been claimed as independent risk factors for occlusive cardiovascular disease. The aim of this study was to investigate whether these coagulation parameters affect early atherosclerosis, additional to their possible effect on arterial thrombosis.

We used high-resolution quantitative ultrasonography to measure carotid intima-media thickness in 121 healthy volunteers, aged 18 to 56 years. It has previously been demonstrated that an increased artery wall thickness is seen in advanced atherosclerosis. To validate our methodology for relatively young individuals, we assessed the association of intima-media thickness with the risk-factor status of our subjects, by including classical cardiovascular risk factors, e. g. age, sex, serum cholesterol, smoking habits and blood pressure. Thereafter, we studied the effect of factor VII and fibrinogen plasma levels on carotid intimamedia thickness, as well as that of polymorphisms of the factor VII and fibrinogen genes.

All classical risk factors except smoking and family history were associated with intima-media thickness. When adjusted for by multivariate linear regression analysis, age, blood pressure and cholesterol appeared to be independent determinants of intima-media thickness. Factor VII and fibrinogen levels showed no association in multivariate analysis with intima-media thickness. We conclude that artery wall thickness measurement by ultrasound is a useful tool to investigate the role of clotting factors in early atherosclerosis. Factor VII and fibrinogen levels in young and middle-aged volunteers have no association with early artherosclerotic vessel wall changes.
Desulfated Hirugen (Hirudin 54-65) Induces Endothelium-Dependent Relaxation of Porcine Pulmonary Arteries
Authors: Glusa Erika
Published: July 2018

Desulfated hirugen (hirudin 54-65) at concentrations from 0.1 to 2 μM was found to relax PGF2α-precontracted ring segments of porcine pulmonary arteries with intact endothelium. The relaxation was associated with a pronounced increase in cGMP in the vessels. This endothelium-dependent relaxant effect depended on the extracellular calcium ion concentration and was probably due to the release of endothelium-derived NO as indicated by its susceptibility to blockade of the NO synthesis by NG-nitro-L-arginine. In the presence of indomethacin (3 μM) the maximum hirugen effect was significantly diminished by about 25%. In contrast, neither the sulfated hirugen nor recombinant desulfato hirudin at equimolar concentrations exerted endothelium-dependent relaxation. Hence, the relaxant effect did not correspond to the anticoagulant activity. Desulfated hirugen can be assigned to the group of well-known peptides causing vasodilatation via an endothelium-dependent mechanism.
The Influence of Acenocumarole on the Fibrinogen-turnover in Normal Subjects, Venous Thrombosis and Congestive Heart Failure
Authors: Maas A. P. C. van der , Teulings F. A. G , Schopman W , Ottolander G. J. H. den
Published: July 2018

Using 131Iodine-tagged fibrinogen the influence of acenocumarole on the biological half-life of fibrinogen was investigated in healthy patients, patients with venous thrombosis and patients with congestive heart failure.

In 16 healthy patients the mean t½ was 3.8 days. In two of them after administration of acenocumarole the t½ was lengthened. This supports the opinion of a continuous deposition of fibrin on the vascular endothelium in the hemostatic balance.

In 13 patients with venous thrombosis the mean t½ was 2.45 days, lengthening to the normal range after acenocumarole therapy. The time interval between the start of acenocumarole therapy and the moment of normalization of the t½ was approximately 4 days. The prothrombin time-index at this moment was 2.3 (thrombotest 5%), which argues in favour of a vigorous anticoagulant therapy.

In our 10 patients with congestive heart failure probably venous thrombosis occurred in 40%. Prophylactic anticoagulant therapy as in surgical patients therefore has to be considered.
The Kinin System of Human Plasma
Authors: Özge-Anwar Ayşe H. , Movat H. Z , Scott J. G
Published: July 2018

Human plasma was adsorbed to celite. The celite eluates were chromatographed on QAE-Sephadex A-50, followed by gel filtration, isoelectric focusing and preparative polyacrylamide electrophoresis.

By anion-exchange chromatography, factor XI a, kallikrein and y-globulin were isolated from the excluded protein peak. Factor XIa (MW ∼170,000) corrected the deficiency in plasmas deficient in factors XII or XI, but had no effect on the kininsystem. Its isoelectric point was about 8.0-8.5. Kallikrein had a molecular weight of ∼ 90,000 and a pi of 7.8-8.0 The two substances could be isolated also by polyacrylamide electrophoresis.

Highly anionic fractions contained a fragment of factor XII a (prekallikrein activator), which activated prekallikrein and retained some of the clot-promoting property of the intact factor XIIa molecule. Its molecular weight was about 37,000, the pi about 4.4 and it migrated as a prealbumin by disc electrophoresis.

It is concluded that, by massive contact exposure, most of factor XII a converts to the highly anionic, low-molecular-weight prekallikrein activator. Since the prekallikrein activator is a fragment of factor XII a, we recommend that it be referred to as “XII f”.
The Effect of Several Tissue Thromboplastins on the Activation of the Abnormal Factor X (Factor X Friuli)
Authors: Girolami A , Lazzarin M , Molaro G
Published: July 2018

The effect of several tissue thromboplastins on the abnormal factor X (factor X Friuli) has been investigated.

The prothrombin time varied between 33.6 and 69 sec. The prothrombin time percentile values (saline dilution curve and Quick’s formula for citrated plasma) varied between 6.6 and 22% and between 10.9 and 32.8%, respectively. The prothrombin time patient/normal ratio varied between 2.24 and 4.43.

The factor X level varied between 3.5 and 20% of normal.

Significant correlations were found to exist between the percentile factor X level and the prothrombin time in seconds, the percentile prothrombin time values and the prothrombin time patient/normal ratio. Thromboplastins of human origin yielded the lowest factor X values namely 5% thereby appearing to be practically “inert” with regard to the abnormal factor X. Thromboplastins obtained from rabbit lung on the contrary yielded the highest values, namely 15.3%. Thromboplastins obtained from simian or rabbit brain gave values intermediate between these two extremes.
Urokinase Levels in Urine after Nicotinic Acid Injection
Authors: Holemans R , McConnell D , Johnston J.G
Published: July 2018

1. Blood fibrinolytic activity and urokinase excretion were studied in a group of young healthy male subjects before and after intravenous injection of nicotinic acid. Although each of the subjects had a marked increase in blood fibrinolytic activity after injection of nicotinic acid, there was no significant change in urokinase excretion.

2. These data do not support the theory that urokinase is filtered blood activator of plasminogen. It is suggested that release of urokinase into urine is primarily dependent on the time of contact between urine and walls of collecting ducts and other parts of the urine conducting system.
The Monoiodoacetate (MIA) Tolerance Test, a New Quantitative Method for the Fibrin Stabilizing Factor (Factor XIII) Assay
Authors: Sigg P
Published: July 2018

A new quantitative test for the fibrin stabilizing factor (FSF, factor XIII) determination is described. The test is based on the principle of the reversible inhibition of the FSF action by monoiodoacetate (MIA).

The definition of the MIA tolerance is given. The normal range is about 45. The MIA tolerance is studied under various conditions. No FSF free material is necessary for its performance.
Blood Factor XI after Fat-Rich Meals
Authors: Egeberg O
Published: July 2018

Controlled meals were given to normal persons and to certain patients, and blood coagulation was investigated before and after the meal, especially with an assay sensitive for activated antihemophilic C factor (AHC5 = activated f. XI).

After bread and rich amounts of margarine (produced mainly from hydrogenated marine oils), the AHC’ assay in fresh plasma registered a significant acceleration about 5 hours after the meal. No significant changes were measured in the levels of AHA (f. VIII), AHB (f. IX) and proconvertin (f. VII). A weaker tendency to acceleration in AHC5 assay seemed also to occur after intake of vegetable margarine (produced from hydrogenated vegetable oils). Bread with low or high amounts of cow butter gave no acceleration.

The active principle in the postprandial plasmas could not be demonstrated after a few days of storage at — 20° C.

The hypothesis that the acceleration effect is due to an activation of blood AHC was supported by the observation that no corresponding effect was measured after margarine meals to patients with AHC deficiency.

Patients with von Willebrand’s disease showed the same activation as normals.

The activation seemed to be prevented by intake of linseed oil prior to the margarine meal.

The results are discussed.
Use of a Lyophilized Reference Plasma to Compare Coagulation Test Procedures
Authors: Kahan J , Nohén I
Published: July 2018

In 4 collaborative trials, involving a varying number of hospital laboratories in the Stockholm area, the coagulation activity of different test materials was estimated with the one-stage prothrombin tests routinely used in the laboratories, viz. Normotest, Simplastin-A and Thrombotest. The test materials included different batches of a lyophilized reference plasma, deep-frozen specimens of diluted and undiluted normal plasmas, and fresh and deep-frozen specimens from patients on long-term oral anticoagulant therapy.

Although a close relationship was found between different methods, Simplastin-A gave consistently lower values than Normotest, the difference being proportional to the estimated activity. The discrepancy was of about the same magnitude on all the test materials, and was probably due to a divergence between the manufacturers’ procedures used to set “normal percentage activity”, as well as to a varying ratio of measured activity to plasma concentration. The extent of discrepancy may vary with the batch-to-batch variation of thromboplastin reagents.

The close agreement between results obtained on different test materials suggests that the investigated reference plasma could be used to calibrate the examined thromboplastin reagents, and to compare the degree of hypocoagulability estimated by the examined PIVKA-insensitive thromboplastin reagents.

The assigned coagulation activity of different batches of the reference plasma agreed closely with experimentally obtained values. The stability of supplied batches was satisfactory as judged from the reproducibility of repeated measurements. The variability of test procedures was approximately the same on different test materials.
Comparative Inhibition of Extrinsic and Intrinsic Thrombin Generation by Standard Heparin, a Low Molecular Weight Heparin and the Synthetic ATIII-Binding Pentasaccharide
Authors: Lormeau Jean-Claude , Herault Jean-Pascal
Published: July 2018

The inhibiting effect of standard heparin, CY216 and the ATIII-binding synthetic pentasaccharide on extrinsic and intrinsic thrombin generation were quantified by evaluating the decrease of the total amount of active thrombin appearing in plasma after triggering coagulation.

Heparin as well as CY 216 produced the same quantitative inhibition of extrinsic and intrinsic TGs whereas pentasaccharide inhibited more efficiently extrinsic TG.

This pattern of inhibition was further confirmed on pure extrinsic or intrinsic coagulation respectively in factor IX- and factor VII-depleted plasmas.

Furthermore, selective suppression of the anti-thrombin activity of CY 216 by limited amounts of PF4 affected the intrinsic TG inhibition more markedly than the extrinsic one.

It was concluded that anticoagulant activity produced mainly through thrombin scavenging leads to similar quantitative impairment of extrinsic and intrinsic coagulation, while selective ATIII-mediated factor Xa inhibition results in a more marked effect against the extrinsic system.
Acquired Coagulopathy In Eight Immunosuppressed Patients With Disseminated Aspergillosis
Authors: Hussey C V , McClellan S L , Annesley W H , Farmer S , Komorowski R
Published: July 2018

We report a retrospective review of 8 immunosuppressed renal transplant patients with disseminated invasive aspergillosis and a profound coagulopathy; which in three of the cases resulted in uncontrollable hemorrhage. The coagulopathy is characterized by hypofibrinogenemia, modest prolongation of the PT and PTT, and modest elevation of FSP’s. In six of eight cases there was hypotension refractory to dopamine infusion. The diagnosis of DIC was excluded on the basis of FSP’s <30 μg/ml and the relatively mild prolongations of the PT and PTT. Primary fibrinolysis was excluded by normal Euglobulin lysis times. The index case displayed the most profound hemorrhagic manifestations; which did not respond to therapeutic doses of EACA or heparin. Mild correction of the thrombin time and a marked but transient clinical response did occur with intravenous protamine sulfate.

Strains of Aspergillus were isolated from premortem cultures in 3 cases and postmortem cultures in the remaining 5. All isolates were found to produce proteolytic enzymes with fibrinogenolytic and fibrinolytic activities. The clinical coagulopathy, refractory hypotension and abnormal coagulation test results in the cases were quite similar to the results obtained when pharmacologic doses of Brinase (a well characterized proteolytic enzyme derived from Aspergillus oryzeae) were administered to dogs. Thus, we propose that our patients’ coagulopathies were secondary to the in vivo effects of a nonspecific protease elaborated by their invasive aspergilli.
Comparison Of 125-I Fibrinogen Kinetics And Fibrinopeptide A In Patients With Disseminated Neoplasias
Authors: Mombelli G , Roux A , Haeberli A , Straub P W
Published: July 2018

To answer the question of whether and to what extent an elevated fibrinopeptide A (FPA) or an accelerated fibrinogen turnover reflect circulating thrombin action, the effect of heparin on FPA and on 125-I fibrinogen kinetics was studied in 15 patients with disseminated neoplasias. The plasma FPA levels were grossly elevated (4.6-20, mean 12.5 ng/ml) in 6 patients with evidence of thromboembolic disease or DIC, and moderately to grossly elevated (0.4-10.4, mean 4.8 ng/ml) in most of the other patients. The FPA fall found in 10/10 patients after heparin bolus suggested that plasma FPA were reflecting thrombin action on fibrinogen. However, in several cases the slew rate of FPA decrease was consistent with localized or extravascular, rather than with circulating thrombin action.

Although continuous heparin therapy normalized the FPA levels in 5 of the 6 treated patients, the acceleration of fibrinogen turnover was as important as in untreated patients (mean values in heparin treated and untreated patients: half-life t1/2: 2.85 vs 2.23 d, catabolic rate constant j3: 0.40 vs 0.48 d-1, turnover: 67.6 vs 70.2 mg/kg/d, respectively, with normal values of t1/2: 3.78-4.57 d, j3: 0.22-0.33 d-1, turnover 16.6-26.6 mg/kg/d). The comparison between data of the FPA-RIA and fibrinogen kinetics suggests that mechanisms other than thrombin-mediated fibrin formation substantially contributed to increase the fibrinogen turnover. It is concluded that the results of the FPA-RIA and of the 125-I fibrinogen kinetics have to be interpreted with caution in the diagnosis of low-grade or compensated intravascular coagulation.
Activation And “Inactivation” Of A Plasminogen Proactivator (Preurokinase) In Human Tissue Culture Media
Authors: Wijngaards G , Bernik M B
Published: July 2018

Besides active plasminogen activators, the synthesis of a proactivator (preurokinase) has been reported in cell and tissue cultures. It is suggested that slow activation of the proactivator in the culture medium occurs by an unknown proteolytic mechanism. Rapid activation can be obtained by incubation with plasmin or trypsin, whereas incubation with thrombin results in a preurokinase which has lost its capacity to be activated. These studies were performed with the fibrin plate method (FPM) which in itself involves further exposure of preurokinase to plasmin over a 16 to 20 hr period.

In the present study the effect of incubation of some culture media with plasmin and thrombin, on the activation of proactivator, was measured using the clot lysis time method (CLTM) and an immediate assay with the synthetic substrate S-2322.

The results with the CLTM showed that incubation of particular culture media with plasmin increases the activator activity immunologically related to urokinase. Incubation with thrombin was without effect, but when followed by incubation with plasmin a decreased level of activatable preurokinase was found. The decrease correlated positively with the thrombin concentration and incubation time and negatively with previous treatment of thrombin with antithrombin III. The S-2322 method showed very similar results, while comparison of the results of both CLTM and S-2322 method with those of the FPM revealed only small differences. Results indicate that preurokinase is hardly activated by plasmin in fibrinolytic assays, not even during the long incubation time of the FPM. Accordingly, it seems unlikely that there will be a positive feedback in thrombolysis as a consequence of activation of preurokinase by plasmin. (Supported, in part, by NATO Research grant RG 018.80).
On The Conversion Of High Molecular Weight Urokinase To The Low Molecular Weight Form
Authors: Barlow Grant H , Francis Charles W , Marder Victor J
Published: July 2018

The conversion of high molecular weight urokinase (HMW) to low molecular weight urokinase (LWM) by plasmin in vitro has been studied. The two molecular weight forms of urokinase were separated by SDS polyacrylamide gradient gel electrophoresis and active enzyme extracted from gel segments into isotonic saline after slicing the gel at 5 mm intervals. Extracts from gel segments were analyzed by the fibrin plate method, and electrophoretic separation of the two forms were shown to be complete by comparison with the migration of purified standards and by the absence of lytic zones between the peaks of activity. HMW was incubated with plasminogen and fibrinogen for various time intervals from 2.5 to 10 minutes, enzymatic activity inhibited with aprotinin, and the samples subjected to electrophoresis. Conversion from HMW to LMW was apparent in as little as 2.5 minutes and continued for the 10 minute duration of the experiments. Similar experiments starting with LMW showed no change in molecular weight. Incubation of HMW without plasminogen resulted in no conversion to LMW implying that this reaction was not autocatalytic. The same conversion may occur in vivo during therapeutic administration of urokinase when a “lytic state” is produced and plasmin activity is present. Possible conversion of HMW to LMW in vivo will need to be considered in evaluating the relative therapeutic efficacy of different urokinase preparations and in interpreting the results of clinical trials.
Purification Of High Affinity Plasminogen Activator (HAPA) From Blood By Affinity Chromatography On Fibrin-Celite
Authors: Husain S , Gurewich V , Lipinski B
Published: July 2018

Plasminogen activator (PA) from tissue and blood is known to have a high affinity for fibrin. This property was used to purify the HAPA from blood plasma. Flow properties and surface area sufficient for fibrin affinity chromatography were achieved by clotting fibrinogen in the presence of celite. This prevented gel formation. 50-70% of the PA in blood was found tightly bound to fibrin but could be eluted with arginine (0.2M). (Celite alone did not bind HAPA). SDS gel electrophoresis of the arginine eluate showed 2 major and 1 minor band. Gel filtration (Sephadex G-100 superfine) of the arginine eluate resulted in separation of a single activator peak corresponding to a MW of 70,000 daltons. Gel electrophoresis of the activator peak showed 2 bands corresponding to 70,000 and 40,000 daltons. The latter protein band is believed to represent a degradation product produced during sample preparation since its elaboration could be inhibited by adding proteolytic inhibitors. The purified HAPA is unstable and has a relatively low specific activity of 500 CTA units/mg, suggesting that it may be a proactivator. The unique fibrin affinity of the HAPA is believed to contribute importantly to the specificity of plasmin action in blood which appears to be confined to fibrin. Two other activators (145,000 and 70,000 daltons) were identified in the breakthrough peak. Their relationship to HAPA is unknown. Plasminogen also was in the breakthrough peak and was not adsorbed to fibrin under these experimental conditions. Affinity chromatography on fibrin-celite may lend itself to the isolation of HAPA from sources other than blood and for studying the interaction of other proteins on the fibrin surface.
On The Nature Of The Activated Prothrombin Complex
Authors: Penner J A , Cobel-Geard R , Hassouna H I
Published: July 2018

Prothrombin complex concentrates containing FVIII bypassing activity have been employed effectively in the management of patients with factor VIII and IX inhibitors. The active component has not been identified although the protease forms of factor IX and X, as well as VII exist in variable concentrations in these products.

As a means of establishing the role of each factor in the concentrates, monospecific antibodies to prothrombin, FX and FVII were coupled to Sepharose 4B by means of cross linking reagent cyanogen bromide. These insol- ubilized antibodies were used to selectively remove all prothrombin FX or FVII from the therapeutic concentrate, Autoplex (570 u/vial) supplied by Hyland Labs, Costa Mesa, by batch adsorption. A control was prepared by reacting the concentrate with cyanogen bromide treated beads whose active sites had been blocked with ethanolamine. Successful removal of specific factors from concentrates was evaluated by immunodiffusion assays and by standard clotting assays using substrate deficient plasma. Thrombin was not found to be present in any of the products following extraction. Thrombogenicity was tested in an animal model. Concentrates reacted with cyanogen bromide beads as a control and those lacking prothrombin were found to shorten clotting time of FVIII deficient plasma and to trigger intravascular coagulation in the animals (D.I.C.). Removal of FVII produced a concentrate that was more active than the control with respect to FVIII correction and induction of D.I.C. Concentrates depleted of FX, on the other hand, lost their capacity to correct FVIII deficient plasma and to initiate D.I.C. Our findings would suggest that the content of FX and its active form FXa plays a major role in the concentrates FVIII correcting activity and most likely is responsible for its thrombogenic characteristics.
Kinetic Analysis Of Prothrombin Activation By Des (l-44) Factor Xa
Authors: Skogen W F , Esmon C T , Cox A C
Published: July 2018

The region of factor X containing the gla residues was released by mild chymotryptic digestion and the resulting Des (1-44) factor X was converted to its activated form with the Russell’s viper venom factor X activator as described by others. The modified enzyme, factor Xa(-gd), retains its ability to activate prothrombin, the activation was still accelerated by factor Va, but the activation was no longer accelerated by phospholipid. The interaction between factor Va and either factor Xa or factor Xa(-gd) was studied kinetically. The rate of prothrombin activation was measured as a function of increased factor Va concentration in reaction mixtures where the factor Xa or factor Xa(-gd), prothrombin, and Ca2+ concentrations were constant. In the absence of phospholipid, analysis of the above data indicated an apparent dissociation constant (Kd’) of factor Xa for factor Va of 3.6 x 10-8 M. The removal of the gla domain lowered the apparent affinity of factor Xa for factor Va to 2.3 x 10-6 M indicating a role of the gla domain in the factor Xa-factor Va interaction even in the absence of phospholipid. Although the affinity was lowered, the V max of the reaction was identical for factdr Xa and factor Xa(-gd) in the presence of saturating concentrations of factor Va. With the addition of phospholipid, the Kd’ of factor Xa for factor Va was 4.7 x 10-10 M and V max increased some 297 fold. Phospholipid had no effect on the Kd’ of the factor Xa(-gd)-factor Va complex (Kd’ s 2.3 x 10-6 M) and V max was unaltered. These results demonstrate that phospholipid has little or no effect on factor Va function when factor Xa has lost its gla mediated Ca2+ binding sites.
Polyvinylpyrrolidone (PVP). A New Plama Fractionation Agent
Authors: Casillas G , Simonetti C
Published: July 2018

The techniques used currently to prepare F.VIII concentrates are chiefly based on alcoholic, cryo or PEG precipitation.

Here we described the preparation of F.VIII concentrate from human and bovine plasma using a new precipitating agent (PVP). The precipitation curves of F.VIII and fibrinogen in function of the PVP concentration,pH and temperature were studied and then the optimum conditions as regard recovery,purification and fibrinogen content were adjusted.

A concentrate ( 1/10 de volume of the original plasma) containing 8U F.VIII/ml (recovery 80%), 16mg/ml protein and 7mg/ml fibrinogen (recovery 20%) is obtained from human plasma in the following conditions: 4% PVP concentration, 5°C and extraction of the precipitate at 2-3°C with a 0.15M NaCl , 0.5M glycine solution.

For bovine plasma the conditions are similarexcept for the precipitation,which is performed at room temperature (15-20°C).The recovery of F.VIII and fibrinogen is 90% and 10% respectively and the protein content 12mg/ml. Small variations in the pH of plasmas do not modify the results.
Relationship Between Fibrinogen Proteolysis, Platelet Release And Fibrin Deposition Following Total Hip Replacement
Authors: Lane D A , Allen-Mersh T G , Ireland H , Wolff S , Jennings S , Grant P
Published: July 2018

It has been postulated that fibrin deposition is controlled by the relative competition of thrombin and plasmin for fibrin I. We have tested this hypothesis by measuring haemostatic activation products in the plasma of patients undergoing hip replacement. Thrombin sensitive fragment fibrinopeptide A (FpA), plasmin sensitive fragment Bβ1-42 and β thromboglobulin (βTG) have been measured before and after operation (n=26). The incidence of venous thrombosis was assessed by phlebography and I125 fibrinogen scanning. The mean preoperative FpA, Bβ1-42 and βTG concentrations were 1.80, 4.22 and 0.99 pmol/ml respectively. The mean FpA and βTG levels rose to 3.07 and 1.56 pmol/ml respectively on the sixth day after operation but the mean Bβ1-42 level rose more rapidly to a maximum of 10.9 pmol/ml on the fourth day after operation. In those patients who developed a thrombosis (n=9), the mean FpA level was higher on the first day after operation (2.83 pmol/ml) than in those patients (n=17) in whom thrombosis did not occur (1.66 pmol/ml). Conversly, the mean Bβ1-42 level was lower (4.76 pmol/ml) in those who developed a thrombus than in those without thrombus (6.79 pmol/ml). When the postoperative day 1 results were expressed as a ratio of FpA/Bβ1-42, the corresponding mean values of this ratio for the two groups of patients were 0.74 and 0.37. These results demonstrate that (a) there is an activation of the coagulation and fibrinolytic systems, and of platelets following hip replacement surgery (b) thrombus formation following major surgery is characterised by an increased action of thrombin on fibrinogen and a reduced action of plasmin on either fibrinogen or fibrin I (c) assays for FpA and Bβ1-42 may be useful for the detection of developing thrombi.
Studies On Coagulation Physiology In Perioperative Thromboembolism Prophylaxis In Surgery
Authors: Koppenhagen K , Häring A , Zühlke H , Wiechmann A , Matthes M , Hardieck J , Rieser R , Tank E , Breddin K
Published: July 2018

In a prospective and randomized double-blind study in 630 general surgery patients with different thromboembolism prophylaxis (130 patients with 5000 and 122 with 2500 I.U. of heparin, 128 with a fixed combination of 2500 I.U. of heparin and 0.5 mg dihydroergotamine ((2500-heparin-DHE)), 124 with 0.5 mg DHE and 126 with a placebo, 3 × daily) the influence of the medication on blood coagulation was examined by repeated pre-and post-operative determinations of blood-and coagulation parameters (activated partial thromboplastin time, heparin-plasma level, AT III, thromboplastin time, fibrinogen, thrombin time, thrombocyte aggregation test, β-thromboglobulin, Hb, erythrocytes, hematocrit, thrombocytes and differential blood picture). The frequency of postoperative thromboses and pulmonary embolisms was investigated by means of the radiofibrinogen test and lung scintigraphy. The results show that the lowest thromboembolism rate occurs in that patient collective in which there is in addition to the heparin application a simultaneous hemostatic effect of DHE. Side effects of the prophylaxis and influences on blood coagulation are dependent on the amount of heparin administered both in the single-drug low-dose treatment and in the combination therapy. The lowest rate of side effects was found in the group receiving 3×2500 I.U. of heparin and in the combination group 2500-heparin-DHE, but the combination treatment additionally affords the same thromboembolism protection as the routinely applied 3×5000 I.E. of low dose heparin.
Hypercoagulation And The Predictability Of Thromboembolic Phenomena In Total Hip And Total Knee Surgery
Authors: Kurica K , Holmes J , Peck S , Cox B , Brantigan C , Wenzel W
Published: July 2018

Forty patients admitted for elective total hip and total knee surgery were evaluated to determine the efficacy of the hypercoagulable profile in the predictability of high and low risk patients for the development of thromboembolic phenomena (proximal deep vein thrombosis and pulmonary embolism) after surgery. Patients were evaluated pre operatively with 99m Tc MAA venograms, ventilation perfusion lung scans, pneumatic plethysmography and a hypercoagulable profile including: thrombin generation test, plasma clot impedance test, antithrombin III. Patients with evidence of thromboembolic phenomena by 99m Tc scans or positive plethysmography were excluded. The hypercoagulable profile was repeated on the first post operative day. Both the hypercoagulable profile and the 99m Tc scans were repeated on the tenth post operative day or if the patient developed any signs or symptoms of thromboembolic phenomena. There was no prophylaxis given.

Ten patients were hypercoagulable pre operatively; four developed post operative thromboembolic phenomena. Nine patients became hypercoagulable post operatively; three patients developed thromboembolic phenomena as determined by 99m Tc criteria. The remaining nineteen patients were never hypercoagulable throughout their hospital course and were discharged without evidence of thromboembolic phenomena by 99m Tc imaging criteria.

The hypercoagulable screen successfully separates those patients at high and low risks for the development of post operative thromboembolic phenomena after total hip and knee surgery. These results are statistically significant to the one tail p 0.00001 level using Fisher s exact test.