bluuebunny/crossref_metadata_2025 huggingface dataset:
Pilotprojekt „Telefonisch-psychologische Beratung Unfallverletzter“ der Berufsgenossenschaft für Gesundheitsdienst und Wohlfahrtspflege – Wie wird das Angebot bewertet?
Authors: Ahnert Jutta , Vogel Heiner , Richard Matthias , Wilhelm Jürgen , Drechsel-Schlund Claudia , Neuderth Silke
Published: July 2018

Im Rahmen eines Pilotprojektes wurde ein telefonisch-psychologisches Beratungsangebot in 4 Bezirksverwaltungen der Berufsgenossenschaft für Gesundheitsdienst und Wohlfahrtspflege (BGW) implementiert und formativ evaluiert. Sachbearbeiter, Psychotherapeuten und die Versicherten wurden bezüglich ihrer Erfahrungen und Zufriedenheit mit dem Angebot befragt. Das telefonische Beratungsangebot wurde von ca. 15,5% der angeschriebenen Versicherten angenommen. Versicherte, die das Angebot angenommen haben, schätzen sich tendenziell stärker psychisch belastet ein, sind 3 Monate nach der Angebotsunterbreitung häufiger noch krankgeschrieben und nehmen im Anschluss häufiger eine Psychotherapie in Anspruch. Die Telefonate mit dem Psychotherapeuten werden von den meisten als hilfreich eingeschätzt. Auch von den beteiligten Psychotherapeuten und den Sachbearbeitern wird das Angebot positiv bewertet. Insgesamt kann die Implementierung als gelungen bewertet werden. Ein Wirksamkeitsnachweis im Rahmen einer randomisierten kontrollierten Studie wäre der nächste Schritt.
Factor VII and Fibrinogen Levels as Risk Factors for Venous Thrombosis
Authors: Koster T , Rosendaal F R , Reitsma P H , Velden P A van der , Briët E , Vandenbroucke J P
Published: July 2018

The plasma levels of coagulation factor VII and fibrinogen are well known risk factors for arterial thrombosis. We tested the hypothesis that this association also exists for venous thrombosis. Additionally, MspI and Haelll polymorphisms in the factor VII and fibrinogen genes have recently been reported to be associated with the concentration of both proteins in the plasma. However, no conclusion could be drawn with respect to an increase or decrease in thrombosis risk. We undertook a population-based case-control study, in which 199 patients with a first, objectively confirmed episode of deep vein thrombosis, aged less than 70, and without a known malignant disorder were compared to 199 age-and sex-matched healthy controls, to evaluate the clinical importance of these reported findings.

For fibrinogen we found a positive level-related association between the plasma fibrinogen level and thrombotic risk. Subjects with a plasma fibrinogen greater than 5 g/1 had an almost 4-fold increase of thrombosis risk. The frequencies of the different Haelll genotypes were out of balance only for the thrombosis patients, with a deficit of the H1H2 genotype. Possession of an H1H2 genotype was associated with a 40% reduction in thrombosis risk.

For factor VII, neither the plasma level nor the MspI genotypes were related to deep vein thrombosis, although possession of a M2 allele was clearly associated with significantly lower factor VII levels. The frequencies of the Mspl-genotypes were the same for patients and control subjects and, exhibited Hardy-Weinberg equilibrium.

Our results support that plasma fibrinogen, a determinant of arterial thrombosis is also a risk factor for venous thrombosis, while factor VII plasma concentration is unrelated to deep vein thrombosis, which is supported by the data from the DNA analysis of polymorphisms.
Low-Affinity Material Does not Contribute to the Antithrombotic Activity of Orgaran (Org 10172) in Human Plasma
Authors: Zammit Adrian , Dawes Joan
Published: July 2018

Orgaran is a LMW heparinoid composed of heparan sulphate (83% wlw) of which 4-5% has high affinity for antithrombin, dermatan sulphate (12% w/w) and chondroitin sulphate (59 wlw). To examine the contribution of the low-affinity fraction to Orgaran’s antithrombotic activity we have quantitated the binding of plasma proteins to Orgaran and its component fractions in whole, hirudin-anticoagulated human plasma. Antithrombin, largely bound to the high-affinity fraction, and histidine-rich glycoprotein, interacting with low-affinity components, were the dominant proteins bound to Orgaran. Vitronectin, fibrinogen, fibronectin, heparin cofactor 11, and apolipoprotein B were also detected in small amounts. The ratio of bound antithrombin, histidine- rich glycoprotein and vitronectin to GAG was negatively correlated with the Orgaran concentration in plasma, implying that the efficacy of Orgaran may not be linearly related to dose. Binding of antithrombin to the high-affinity fraction was not decreased by other plasma proteins or affected by addition of low-affinity material. Moreover, the antithrombin and anti-factor Xa activities of the high-affinity material were unaltered by low-affinity GAGs. On the basis of our results we conclude that the low-affinity material does not contribute to the antithrombotic activity of Orgaran by binding non-anticoagulant plasma proteins and releasing the high-affinity chains to interact with antithrombin and its target proteinases.
Physical Studies on Isolated Human Prothrombin Fragment-2. Comparisons with Human Prothrombin Fragment-1
Authors: Schaefer Daniel J , Scott Mary E , Gabriel Don A , Gerth Jean L , Aronson David L , Hiskey Richard G , Koehler Karl A
Published: July 2018

Variation of pH strongly affects the fluorescence intensity of human prothrombin fragment-1 in a manner suggesting contributions from a number of protropic equilibria including groups with apparent pKa values near 3.0. These results suggest a structural role for pKa
1 of γ-carboxyglutamic acid moieties. Added calcium ions (9 mM calcium chloride) quench the fluorescence titration curve.uniformly above pH 4. Below pH 4, however, the titration curve in the presence of calcium ions suggests that calcium-ion-dependent processes leading to fluorescence quenching are pH-dependent. Upon back titration of human fragment-1, from pH 9, hysteresis is observed.

Human prothrombin fragment-2 fluorescence titration curves are relatively broad at low pH suggesting the titration of normal carboxyl groups. The titration curves of fragment-2 are not affected by the presence of calcium ions, and hysteresis occurs upon back titration from low pH values. Circular dichroism (CD) Cotton effects appear at 232 nm and 280 nm and a trough appears at 203 nm in the CD spectrum of human prothrombin fragment-2. The Cotton effects in the region from 230 nm to 300 nm are sensitive to pH, ellipticity values at 232 nm increasing from approximately 300 at pH 2.5 to 1300 (degree-cm/decimole) at neutral pH and finally become negative at high pH values. In contrast to fragment-1, at neutral pH the fragment-2 Cotton effect at 232 nm is insensitive to the presence of 8 mM calcium chloride.
Effect of Sodium Chloride on Limulus Amebocyte Lysate
Authors: Schleef Raymond R , Kenney Dianne M , Shepro David
Published: July 2018

Concentrations of sodium chloride up to 3 M increase the time necessary for the clot formation from Limulus amebocyte lysate (LAL) induced with endotoxin. Sodium chloride at a concentration of 4 M prevents clot formation by either precipitation or denaturation of procoagulase. The time necessary for the activation of procoagulase by endotoxin is increased by a change in the sodium chloride concentration from 0.15 M to 0.588 M. No effect on the proteolytic phase or the polymerization phase of the clotting reaction is detected by the increase in sodium chloride concentration from 0.15 M to 0.588 M. The authors conclude that increased sodium chloride concentrations may aid the isolation of procoagulase.
The Binding of Diiodosalicylate and Flufenamate to the Plasma Antiactivator: Analysis of Chemical Fibrinolysis
Authors: Nanninga L B
Published: July 2018

The fibrinolytic effect of diiodosalicylate was expressed as apparent units urokinase. The dissociation constant of the urokinase-inhibitor complex is increased 19 times in the presence of 10-2 M diiodosalicylate. The binding of diiodosalicylate to the antiactivator was estimated and the increase in free urokinase in the presence of diiodosalicylate was calculated. With 10-2 M diiodosalicylate present only 4% of the inhibitor remains free to bind urokinase. Therefore, the fibrinolytic action of diiodosalicylate can be explained on the basis of its binding to the inhibitor and the release of free urokinase.
Direct Measurement of the Amount of Bound Collagen which Stimulates Platelet Aggregation
Authors: Kronick Paul L , Jimenez Sergio A
Published: July 2018

The amount of collagen which binds to platelets has been correlated with aggregating activity in a platelet aggregometer. Aggregating activity requires only 0.22 μg/ml (0.35 μg/ 109 cells) of collagen bound, the reaction saturating with 4.9 μg/ml (7.9 μg/109 cells). On the basis of the fraction of collagen bound and its hydroxyproline/proline ratio, it is concluded that the activity resides in the type I collagen component.
Adsorption of Fibrinogen and Fragment D of Fibrinogen onto the Insolubilized αChain of Fibrin
Authors: Matthias F R
Published: July 2018

After thrombin treatment insolubilized fibrinmonomer, which is obtained from insolubilized fibrinogen covalently bound to agarose, adsorbs soluble fibrin and its derivatives from solutions. The immobilized proteins are attached to the agarose by the ‘A’ αchain. After reduction of the disulfide bridges the β and γchains can be removed from the agarose.After thrombin treatment the immobilized αchain adsorbs fibrinogen and fragment D. To some extent the β and γchain do not seem necessary for the adsorption. The amount adsorbed increases, when thrombin treatment of the insolubilized protein follows the reduction process.This may indicate that the fibrinopeptides ‘A’ of the insolubilized αchain are better accessible after the removal of the β and γchains.
Separation of Plasminogen Activators from Human Uterine Tissue and a Comparison with Activators from Human Urine and Porcine Tissue
Authors: Kok Preben
Published: July 2018

Three types of plasminogen activator could be distinguished in extracts from human uterine tissue. The activators differed in thermostability or in mode of inhibition by EACA.

All the extracts contained stable as well as labile activators. The saline extracts were uniformly inhibited by increasing concentrations of EACA. Extracts made with 2 M ammonium thiocyanate were either uniformly inhibited by EACA or showed deflections indicating contamination with an activator, which was inhibited in a biphasic manner. It was possible to distinguish between: (1) An activator, abundantly present in the tissue, which was uniformly inhibited and stable. (2) Another uniformly inhibited activator, which was labile. (3) An activator, inhibited in a biphasic manner, similar to urokinase, which was present in varying amounts in uteri with the endometrium in the proliferative phase.

Gel filtration of the uterine extracts showed two major activity peaks corresponding to particle sizes of 60,000 dalton and about 10,000 dalton.

Antiserum to purified plasminogen activator, prepared from porcine ovaries, inhibited the activity of the human uterine extracts, but not the activities of human urokinase or urine. Urokinase antiserum in a concentration completely inhibiting human urine or urokinase, inhibited only 10% or less of the activities of human uterine extracts.
Influence of Moderate and Strenuous Daily Physical Activity on Fibrinolytic Activity of Blood: Possibility of Plasminogen Activator Stores Depletion
Authors: Keber Dušan , Stegnar Mojca , Keber Irena , Accetto Bojan
Published: July 2018

Fibrinolysis was studied in 10 alpinists during regular physical activity of different intensity. Blood was sampled at rest and after exposure to submaximal workload on the treadmill on three occasions: before and after 6 months physical conditioning (moderate physical activity), and after 6 weeks of an alpinistic expedition (strenuous physical activity). Measurements included submaximal working capacity, fibrinogen, euglobulin clot lysis time (ELT), whole plasma clot lysis time, and estimations derived from ELT - percent increase in fibrinolytic activity after exercise (RFS), and absolute increase in fibrinolytic activity after exercise (PAR).

Regular moderate activity increased the resting level of ELT, but strenuous activity decreased is. After each treadmill testing, a marked increase in fibrinolytic activity was observed. RFS was unaltered at all three testings. PAR increased after moderate activity, but decreased after strenuous activity.

The results indicate that regular physical activity can lead from enhanced to decreased resting activity of plasminogen activator in blood. It is presumed that increased release of activator during prolonged stress causes partial depletion of endothelial stores with the consequence of decreased activator activity in the blood.
Molecular Study of Glanzmann Thrombasthenia in 3 Patients Issued from 2 Different Families
Authors: Vinciguerra C , Trzeciak M C , Philippe N , Frappaz D , Reynaud J , Dechavanne M , Negrier C
Published: July 2018

In an effort to further understand Glanzmann thrombasthenia (GT) 3 patients from 2 different families were studied. After biochemical and immunological analysis these patients were classified as type I. We observed in the first family a new restriction site for Stu I in exon II of the glycoprotein (GP) Ilia gene caused by a homozygous nonsense mutation: 62 Arg to stop codon. The parents were heterozygotes for this mutation. We found in the second family a previously described nonsense mutation: 584 Arg to stop codon in exon 17 of the GPIIb gene. The father and his two affected sons were heterozygous for this genetic defect. This mutation 62 Arg to stop codon is a new description of a genetic defect associated with GT. Furthermore, the discovery of the same mutation in 3 affected families from different ethnic groups raises the possibility of either a hot spot mutation in the CG dinucleotide region of GPIIb gene, or an ancient mutant allele present in diffuse populations at a relatively high frequency
Fibrin D-Dimer, Haemostatic Factors and Peripheral Arterial Disease
Authors: Lee Amanda J , Fowkes F Gerald R , Lowe Gordon D O , Rumley Ann
Published: July 2018

Several haemostatic factors have been shown to have a predictive role in cardiovascular disease, although their relationship with prevalent peripheral arterial disease is not well reported. Using a random sample of 1592 men and women aged 55-74 years from Edinburgh, Scotland, we examined the relationship of von Willebrand factor (vWF), tissue plasminogen activator (t-PA) and fibrin D-dimer antigens and factor VII activity to peripheral arterial disease. t-PA antigen and fibrin D-dimer showed significant linear trends of increased levels with increasing severity of disease in both sexes (p ≤0.01) and vWF showed a similar pattern in men only (p ≤0.01). On multivariate analysis, fibrin D-dimer was independently related to the risk of intermittent claudication (p ≤0.01) and, among men, to the extent of arterial narrowing in the lower limb, as measured by the ankle brachial pressure index, (ABPI) (p ≤0.001). These results are further evidence of a role for intravascular fibrin deposition in the development of peripheral atherosclerosis.
Environmental and Genetic Factors in Relation to Elevated Circulating Levels of Plasminogen Activator Inhibitor-1 in Caucasian Patients with Non-Insulin-Dependent Diabetes Mellitus
Authors: Mansfield Michael W , Stickland Max H , Grant Peter J
Published: July 2018

To investigate the interaction of metabolic and genetic factors in relation to PAI-1, genotype was determined at a 4G/5G polymorphism in the PAI-1 gene promoter and at a Hind III RFLP of the PAI-1 gene in 189 Caucasian NIDDM patients. PAI-1 levels were equivalent in each genotype group and PAI-1 activity correlated with fasting insulin (r = 0.45), triglyceride (r = 0.39) body mass index (r = 0.44), cholesterol (r = 0.17) and glucose (r = 0.15). The regression slope (B) of PAI-1 activity on triglycerides was steeper in the 4G/4G group than the other two groups: 4G/4G B = 0.91, r = 0.62; 4G/5G B = 0.36, r = 0.27; 5G/5G B = 0.31, r = 0.29 (difference between slopes p = 0.02) and the association between PAI-1 activity and glucose remained only in the 4G/4G group (r = 0.35). These results confirm the association of PAI-1 levels with the features of insulin resistance and indicate that the association between PAI-1 levels and both triglyceride and glucose is influenced by genotype in the region of the PAI-1 gene promoter.
Plasminogen Activator Inhibitor-1 mRNA Is Induced by Hemorrhage in Endothelial and/Mesothelial Cells of the Rat Liver
Authors: Yamashita Masatomo , Darlington Daniel N , Imafuku Shiqichi , Gann Dionald S
Published: July 2018

We have recently shown that plasminogen activator inhibitor-1 (PAI-I) mRNA is elevated after hemorrhage in various tissues including liver. In this study, we set out to identify the cell types in the liver that are responsible for the increase in PAH mRNA after hemorrhage using in situ reverse transcription-polymerase chain reaction (in situ RT-PCR). Male Sprague-Dawley rats were cannulated and subjected to a 20 ml/kg hemorrhage within 3 min or 300 μg/kg of endotoxin. Pour hours later, the livers were harvested, fixed, frozen, and sectioned. RT-PCR showed an increase of PAI-I mRNA in liver 4 h after hemorrhage or endotoxin-treatment. Standard in situ hybridization could not detect PAI-I mRNA in the livers of either the hemorrhage, endotoxin, or control groups. However, in situ RT-PCR detected PAI-1 mRNA in vascular endothelial cells and capsular mesothelial cells, but not in hepatocytes, in both the hemorrhage and endotoxin groups. No signal was found in the control rats, or when the experimental protocol was modified to 1) omit the RT step, 2) precede the RT step with RNA digestion, or 3) use an irrelevant probe. These results demonstrate that hemorrhage induces PAI-1 mRNA in endothelial and mesothelial cells of liver.
Plasminogen Activator Inhibitor-1 (PAI-1) Promoter Polymorphism and Coronary Artery Disease in Non-Insulin-Dependent Diabetes
Authors: Mansfield Michael W , Stickland Max H , Grant Peter J
Published: July 2018

Elevated levels of PAI-1 are found in coronary artery disease (CAD) and non-insulin-dependent diabetes (NIDDM). PAI-1 may be involved in the pathogenesis of CAD through suppression of fibrinolysis, alternatively the high levels may result from vascular damage. There is evidence that PAI-1 levels are related to genotype at a PAI-1 promoter polymorphism. Genotype at this 4G/5G polymorphism was determined in 160 NIDDM (90 males and 70 females) patients with (n = 38) or without (n = 122) clinical evidence of CAD. Levels of cholesterol were higher (6.5 vs 5.9 mM, p <0.01) and of PAI-1 tended to be higher (PAI-1 activity 23.0 vs 20.4 U/ml) with CAD. The frequency of the 4G/4G genotype was increased and the 5G/5G genotype decreased, in the group CAD compared to those without (p <0.05). These results suggest that possession of the 4G/4G PAI-1 promoter genotype is a risk factor for the development of CAD in subjects with NIDDM.
Clinical Outcome of Orthopaedic Patients with Negative Lower Limb Venography at Discharge
Authors: Agnelli Giancarlo , Ranucci Valeria , Veschi Franca , Rinonapoli Emanuele , Lupattelli Luciano , Nenci Giuseppe G
Published: July 2018

Pharmacological prophylaxis for postoperative venous thromboembolism is generally restricted to the hospital stay. A high incidence of deep vein thrombosis (DVT) and pulmonary embolism presenting after hospital discharge has been reported and thus it has been claimed that pharmacological prophylaxis should be continued after discharge. The aim of this study was to perform a prospective survey to assess the prevalence of clinically overt thromboembolic events in hip surgery patients discharged with a negative venography without further pharmacological prophylaxis. We followed-up 213 patients with negative venography at discharge (105 elective hip replacement and 108 hip fracture patients). 186 patients (87.3%) were re-examined as outpatients one to two months after discharge. Five patients reported symptoms of DVT but the diagnosis was not confirmed by objective testing. The remaining 27 patients (12.7%) were followed up through their family doctor or by telephone call; in these patients the follow-up period ranged from 60 days to 2 years. Twenty-two patients (10.3%) were still alive and reported no signs or symptoms of venous thromboembolism. Three patients (1.4%) died for reasons not correlated with venous thromboembolism. Two patients could not be traced due to geographical inaccessibility; they were still alive after 1 year according to the records of their health care district. The results of our study suggest that in hip surgery patients with negative venography the prevalence of clinically overt thromboembolic events after hospital discharge ranges from 0 to 2.2% (95% C. I.). It is conceivable that the majority of late presenting postoperative DVT actually develop during the hospital stay and become symptomatic after hospital discharge.
Flow Cytometric Detection of Activated Platelets in Pregnant Women Prior to the Development of Pre-Eclampsia
Authors: Janes Sarah L , Kyle Phillipa M , Redman Christopher , Goodall Alison H
Published: July 2018

Pre-eclampsia is a common complication of pregnancy, in which platelets may have an early pathogenetic role. In this prospective study a whole blood flow cytometric method has been used to detect circulating activated platelets in pregnant women prior to the development of pre-eclampsia. Activated platelets were identified by bound fibrinogen or by CD63 antigen expression. Of 121 healthy primiparous women studied at 28 weeks of pregnancy, 18 (15%) developed clinical pre-eclampsia six to thirteen weeks later. The platelets of these women showed increased fibrinogen binding ex vivo (5.1% platelets positive, compared with 3.4% in those who completed a normal pregnancy, p <0.02), and increased CD63 antigen expression (0.73% positive compared to 0.45%, p = 0.01). In contrast, no differences between the women with different outcomes were detected at 28 weeks in platelet counts, or plasma ß-thromboglobulin levels. These findings confirm that whole blood flow cytometry is a sensitive technique for investigating platelet activation in a clinical setting and support the hypothesis that platelets have a critical role in the pathogenesis of pre-eclampsia
Targeting of Porcine Pancreatic Phospholipase A2 to Human Platelets: Introduction of an RGD Sequence by Genetic Engineering
Authors: Bekkers A C A P A , Vuurst H van der , Willigen G van , Akkerman J W N , Verheij H M
Published: July 2018

The possibility to induce specific disruption of activated platelets by binding of porcine pancreatic phospholipase A2 (PLA2) was tested by constructing a set of PLA2-mutants containing an Arg-Gly-Asp (RGD) sequence. One mutant was made with RGD as part of a surface-exposed loop (RGDloop). Four mutants were made with RGD as part of a C-terminal extension: one with RGD directly coupled to the C-terminus (RGDc) and three mutants (CRSx) with x = 22,42 and 82 hydrophylic non-charged amino acids between RGD and the enzyme. All mutants retained 20-80% activity of native PLA2 and showed little binding to resting platelets. The binding of the native enzyme and RGDloop was not increased following stimulation. In contrast, the mutants RGDc and CRSx showed stimulation-dependent binding to the platelet receptor GPIIb/IIIa, since GRGDS-peptide and a monoclonal antibody against the complex interfered with binding. In α-thrombin-stimulated platelets, CRS42 and CRS82 induced about 5% hydrolysis of [3H]-arachidonic acid-labeled phospholipids. Stimulation with a combination of a-thrombin and collagen (known to expose phosphatidylserine) increased hydrolysis to 11%. Despite the membrane disruption, the cells did not leak lactate dehydrogenase. We conclude that PLA2 can be targeted to activated platelets by introducing RGD in a C-terminal extension with a minimum distance (42 amino acids) between RGD and the enzyme. However, more hydrolytic activity is required to eliminate activated platelets among a suspension of resting platelets and other blood cells.
Oxidized LDL and Reduction of the Antiaggregating Activity of Nitric Oxide Derived from Endothelial Cells
Authors: Minuz P , Lechi C , Gaino S , Bonapace S , Fontana L , Garbin U , Paluani F , Cominacini L , Zatti M , Lechi A
Published: July 2018

Oxidized LDL has been observed to induce abnormalities in endothelial function which may be relevant for the progression of atherosclerotic lesions. We studied in vitro the possible effects of oxidized LDL on the antiaggregating activity of endothelial cells, which is dependent on release of prostacyclin and nitric oxide. We used an experimental model in which cultured human endothelial cells were placed in the aggregometer in contact with human platelets, after blockade of cyclo-oxygenase by adding acetylsalicylic acid. In this way the antiaggregant effect of endothelial cells was dependent on the release of nitric oxide alone; prevention of antiaggregant activity by preincubation of endothelial cells with 300 μM L-NG-mono-methyl-arginine confirmed this. When this system was used, endothelial cells (2–7.5 X 105ml) almost completely inhibited thrombin-induced (0.02–0.08 U/ml) platelet aggregation (2 × 108 platelets/ml), measured according to Born (11.1% ±8.5 vs 68.6% ±12.6, M ± SD). This antiaggregating activity was reduced when slightly oxidized LDL 100 μg/ml (35.2% ± 14.9, p <0.001), but not native LDL 100 μg/ml (7.5% ± 7.6), was added immediately before aggregation was induced.. Incubation of endothelial cells with oxidized LDL 100 μg/ml for 1 h did not affect the antiaggregating capacity, unless oxidized LDL was present during aggregation (18.3% ± 10.2 vs 35.8% ± 9.6, p <0.02). No significant direct effect of either oxidized or native LDL on stimulated platelet aggregation was observed. Our results indicate that slightly oxidized LDL can reduce the antiaggregating properties of the endothelium, probably by interaction with NO rather than through inhibition of its synthesis.
Post-Partum Factor VIII Inhibitors
Authors: Hauser I , Schneider B , Lechner K
Published: July 2018

In a retrospective study 51 published cases of post-partum factor VIII inhibitors were analyzed with regard to the outcome according to treatment. The overall outcome was favorable with 97% survival at two years. The probability of complete remission (CR, absence of the inhibitor and normalization of factor VIII activity) was almost 100% at 30 months. Steroid treatment appears to be not superior to no treatment, but patients treated with immunosuppressive drugs (cyclophosphamide, azathioprine, 6-mercaptopurine) had a significantly shorter time to CR. In the absence of a randomized trial this analysis may be helpful for decision-making in women with factor VIII post-partum inhibitors. Because of the retrospective study design, conclusions have to be regarded with caution.
Antibodies to Macromolecular Platelet Factor 4-Heparin Complexes in Heparin-induced Thrombocytopenia: a Study of 44 Cases
Authors: Amiral J , Bridey F , Wolf M , Boyer-Neumann C , Fressinaud E , Vissac A M , Peynaud-Debayle E , Dreyfus M , Meyer D
Published: July 2018

As heparin-PF4 (H-PF4) complexes are the target for antibodies associated to heparin-induced thrombocytopenia (HIT), an ELISA has been developed and optimised for testing antibodies binding to H-PF4. This test was consistently negative in 50 healthy subjects (A492 <0.3) and 35 patients with other causes of thrombocytopenia (A492 <0.5). In contrast, 43 out of 44 HIT patients showed antibodies to H-PF4 (A492 = 1.70 ± 0.81) including 5 patients with a negative platelet aggregation test. In one patient with HIT, antibodies to H-PF4 were already present at day 7, whereas platelet counts dropped ≤ 100 × 109/l only at days 11–12. Surprisingly, among 41 patients under heparin for >7 days, 5 showed antibodies to H-PF4, without HIT. These findings underline the major interest of this ELISA for the early diagnosis of HIT. We also showed that LMWH as well as other sulphated polysaccharides can bind to HIT antibodies in the presence of PF4 and that their reactivity is dependent on the molecular weight and the sulphation grade. The mechanism for HIT involves platelet PF4 receptors which bind the macromolecular H-PF4 complexes formed in the presence of a well defined heparin/PF4 ratio.
Familial Dysfibrinogenemia and Thrombophilia
Authors: Haverkate F , Samama M
Published: July 2018

Approximately 250 cases of dysfibrinogenemia have been reported; 55% were asymptomatic (detected by chance), 25% had a tendency to bleeding, and 20% were reported to have a tendency to thrombosis.

To establish a possible association between familial dysfibrinogenemia and thrombophilia, data on cases with both affections were collected in a study within the framework of the SSC Subcommittee on Fibrinogen of the International Society on Thrombosis and Haemostasis. Registry forms of 51 cases were received. Twenty-six cases fulfilled the (arbitrarily chosen) criteria of familial dysfibrinogenemia and of thrombosis not due to other causes. Protein C and protein S deficiency and APC resistance as a cause of thrombosis could not be excluded in probands on anticoagulants or investigated before the discovery of the assays.

The prevalence of dysfibrinogenemia in patients with a history of venous thrombosis is low, i.e. 0.8%, as deduced from 9 studies in 7 countries on 2376 patients. The 26 cases fulfilling the criteria are characterized by predominantly venous thrombosis at a young age. Severe bleeding was rare and limited to bleeding post partum. Homozygosity was established in 2 cases (Marburg and Naples), hypodysfibrinogenemia (less than 1.5 mg antigen per ml) in 5 cases. A high incidence of problems related to pregnancy, in particular thrombosis post partum and spontaneous abortions was noted amongst the 15 women with thrombophilic dysfibrinogen

An association between dysfibrinogenemia and thrombophilia is indicated by studies on relatives of the 26 probands. Analysis of 187 investigated family members showed that thrombophilia affected 20 persons exclusively in the group of 99 relatives with dysfibrinogenemia, no thrombosis was reported in the group of 88 relatives without the defect. Convincing evidence for such an association became apparent for only 5 individual propositi of whom 2 or more family members had both the defect and thrombotic episodes at a young age (Caracas V, Frankfurt IV/Vlissingen, Melun, Naples and Paris V, also named Dusart).

Mainly two mechanisms to explain thrombosis as a consequence of malfunctioning fibrinogen have been suggested: a) A defective binding of thrombin to abnormal fibrin which leads to increased thrombin levels (Malmö, Naples, New York I, Pamplona II, Poitiers), b) A defective stimulatory function of abnormal fibrin in the t-PA mediated fibrinolysis (Argenteuil, Chapel Hill III, Date, New York I, Nijmegen, Pamplona II, Paris V).

Defects at the molecular level, elucidated in 15 out of the 26 cases fulfilling the criteria, were localised in the C-terminal part of the γ-chain (3 cases), in the N-terminal part of the Bβ-chain (3 cases) and in the Aα-chain (4 cases) of fibrinogen. Why a particular molecular defect leads to malfunction of fibrin(ogen) is still unknown.
Incidence of Factor VIII Inhibitor Development in Severe Hemophilia A Patients Treated only with One Brand of Highly Purified Plasma-Derived Concentrate
Authors: Guérois Claude , Laurian Yves , Rothschild Chantal , Parquet-Gernez Armelle , Duclos Anne-Marie , Négrier Claude , Vicariot Monique , Fimbel Béatrice , Fressinaud Edith , Fiks-Sigaud Marianne , Derlon Annie , Berthier Anne-Marie , Gaillard Solange , Bertrand Marie-Anne
Published: July 2018

The incidence of factor VIII inhibitor was studied in a cohort of 56 previously untreated patients with severe hemophilia A (factor VIII below 1 U/dl). They received only one brand of highly purified factor VIII concentrate (HPSD-VIII) prepared by conventional chromatography with a solvent-detergent step for viral inactivation. Followup since the first infusion of HPSD-VIII was from 1 to 76 months (mean = 29) and cumulative exposure days (CED) from 1 to over 100 (median = 26). Five patients (9%) developed an inhibitor after 6 to 19 CED, only one being a high responder (2%), showing a low incidence of inhibitor compared with previous studies using high purity plasma- derived or recombinant products.
Antithrombotic Effect of a Recombinant von Willebrand Factor, VCL, on Nitrogen Laser-Induced Thrombus Formation in Guinea Pig Mesenteric Arteries
Authors: Azzam K , Garfinkel L I , dit Sollier C Bal , Thiam M Cisse , Drouet L
Published: July 2018

To assess the antithrombotic effectiveness of blocking the platelet glycoprotein (GP) Ib/IX receptor for von Willebrand factor (vWF), the antiaggregating and antithrombotic effects were studied in guinea pigs using a recombinant fragment of vWF, Leu 504-Lys 728 with a single intrachain disulfide bond linking residues Cys 509-Cys 695. The inhibitory effect of this peptide, named VCL, was tested in vitro on ristocetin- and botrocetin-induced platelet aggregation and compared to the ADP-induced platelet aggregation. In vivo, the antithrombotic effect of VCL was tested in a model of laser-injured mesentery small arteries and correlated to the ex vivo ristocetin-induced platelet aggregation. In this model of laser-induced thrombus formation, five mesenteric arteries were studied in each animal, and the number of recurrent thrombi during 15 min, the time to visualization and time to formation of first thrombus were recorded.

In vitro, VCL totally abolished ristocetin- and botrocetin-induced platelet aggregation, but had no effect on ADP-induced platelet aggregation. Ex vivo, VCL (0.5 to 2 mg/kg) administered as a bolus i. v. injection inhibits ristocetin-induced platelet aggregation with a duration of action exceeding 1 h. The maximum inhibition was observed 5 min after injection of VCL and was dose related. The same doses of VCL had no significant effect on platelet count and bleeding time. In vivo, VCL (0.5 to 2 mg/kg) had no effect on the appearance of the thrombi formed but produced dose-dependent inhibition of the mean number of recurrent thrombi (the maximal effect was obtained at 5 min following i. v. injection of the highest dose: 0.8 ± 0.2 thrombi versus 4 ± 0.4 thrombi in controls). The three doses of VCL increased the time in which the first thrombus in a concentration-dependent manner was formed. However, the time to visualize the first thrombus was only prolonged in the higher dose-treated group.

These in-vivo studies confirm that VCL induces immediate, potent, and transient antithrombotic effects. Most importantly, this inhibition was achieved without inducing thrombocytopenia nor prolongation of the bleeding time.
Use of a Low-Molecular Weight Heparin (Enoxaparin) or of a Phenformin-like Substance (Moroxydine Chloride) in Primary Early Recurrent Aborters with an Impaired Fibrinolytic Capacity
Authors: Gris Jean-Christophe , Neveu Sylvie , Tailland Marie-Laure , Courtieu Christophe , Marès Pierre , Schved Jean-François
Published: July 2018

An impaired fibrinolytic capacity, defined as an insufficient venous occlusion-induced shortening of the plasma euglobulin clot lysis time, is a common feature in women suffering from primary early recurrent unexplained miscarriages (1,2). We investigated the therapeutic effect of a low-molecular-weight heparin and of a phenformin-like substance.

In a prospective, randomized trial, 30 consecutive patients initially received either enoxaparin, 20 mg per day during one month, or moroxydine chloride, 1200 mg per day during one month. In case of fibrinolytic status normalization, they were treated during 6 months by the beneficial treatment which was planned to be continued during eventual pregnancies. Patients with hypofibrinolysis persistence received the alternative treatment during another month and a new evaluation was performed. No treatment was given when a persistent abnormal response to the venous occlusion test was evidenced. In case of positive response, the treatment was continued during 6 months. The primary study end-points consisted of any of the following: effect of the treatments on the fibrinolytic response; number of patients becoming pregnant during the 6 months following the last venous occlusion test; number of full-term pregnancies.

Concerning the effects on the fibrinolytic system, 20 out of 29 women responded to the first or second-line enoxaparin treatment whereas only 1 woman out of 19 responded to moroxydine chloride (p=0.00002). Concerning the effects on fertility, responders to LMWH were more likely to initiate a new pregnancy than non-responders (16/20 vs 2/10, p=0.002). In patients conceiving, LMWH responders were more likely to obtain live births than nonresponders (13/16 vs. 0/2, p=0.02). The 9 women who had not responded to both treatments and the one who had responded to moroxydine chloride are still childless. Thirteen of the 20 previously childless women who had responded to enoxaparin had a successful pregnancy whilst taking the low-molecular weight heparin (p=0.0009).

The low-molecular weight heparin enoxaparin was associated with successful pregnancies in patients with recurrent unexplained miscarriages associated with an impaired fibrinolytic capacity.
Magnetic Resonance Imaging of Deep Vein Thrombi Correlates with Response to Thrombolytic Therapy
Authors: Francis Charles W , Totterman Saara
Published: July 2018

Fibrinolytic therapy can result in rapid lysis of deep vein thrombi (DVT), but its use is limited by the failure of many patients to respond and by the increased risk of bleeding complications in comparison with anticoagulant therapy alone. Treatment could be improved by the ability to select patients most likely to respond. Since magnetic resonance (MR) imaging may be sensitive to thrombus age and structure, properties related to thrombolytic sensitivity, we have evaluated the ability of MR imaging to predict the response of DVT to thrombolytic therapy. Nine patients with venographically documented proximal DVT were treated with streptokinase, and MR imaging using a gradient recall echo sequence was performed before and after therapy. The proximal leg veins were divided into nine segments in each patient, and thrombus was present in 55 segments. The MR appearance of the thrombus in each segment was evaluated prior to therapy, and the amount of clot lysis was determined by comparing pre- and post-treatment MR images. MR imaging accurately identified thrombus in all cases in comparison with venography and also identified proximal extension into pelvic veins that was not identified venographically. Prior to treatment, the thrombus in eight of nine patients varied in appearance in different vein segments consistent with a course of progressive extension over time. Thrombi with low MR signal occurred more often in patients with symptoms of four days or less, and were also more common in partially occluded segments (10/12, 83%) than with total occlusion (7/43, 16%) (p < .001). Clot lysis correlated with the appearance of the thrombi occurring in 9/17 (53%) segments with a uniform low signal intensity compared to 2/38 segments (5%) with areas of high or intermediate intensity (p < .001). Clot lysis was also correlated with partial vein occlusion and with symptom duration of 4 days or less. However, even among partially occluded segments and in patients with shorter duration of symptoms, clot lysis occurred significantly more often in segments with low MR signal intensity. The association of low MR signal intensity with both shorter symptom duration and incomplete vein obstruction suggests that this appearance identifies newly formed thrombi which may be responsive to thrombolytic therapy. We conclude that MR imaging may be useful in predicting response and selecting patients for thrombolytic therapy.
Studies on the Neutralizing Effects of Protamine on Unfractionated and Low Molecular Weight Heparin (Fragmin®) at the Site of Activation of the Coagulation System in Man
Authors: Wolzt Michael , Weltermann Ansgar , Nieszpaur-Los Malgorzata , Schneider Barbara , Fassolt Anita , Lechner Klaus , Eichler Hans-Georg , Kyrle Paul A
Published: July 2018

In a double-blind, randomized, cross-over study the neutralizing action of protamine towards unfractionated heparin (UFH, 150 U/kg i.v.) and a low molecular weight heparin (LMWH, Fragmin®, 100 anti-Xa U/kg i.v.) was investigated in 15 healthy subjects in vitro by measuring activated partial thromboplastin time (APTT), thrombin time (TT) and anti factor Xa activity (anti-Xa) in venous blood and in vivo by determination of prothrombin fragment 1.2 (f1.2) and thrombin-antithrombin III complexes (TAT) in venous blood and in shed blood. UFH and LMWH caused a prolongation of APTT and TT, an increase in anti-Xa and significantly inhibited f1.2 and TAT formation in shed blood, whereas only a minimal effect on TAT and f1.2 formation in venous blood was noted. Administration of 1 mg protamine/100 U UFH resulted in a near complete reversal of APTT, TT and anti-Xa, whereas lower doses (0.25 and 0.5 mg) were less effective. The effects of UFH on f1.2 and TAT generation in shed blood were partially (60-70%) neutralized only by the high dose (1.0 mg). Application of 1 mg protamine/100 anti-Xa U LMWH caused a near complete reversal of both APTT and TT but had only a weak effect on anti-Xa. In shed blood, the effect of LMWH on TAT and f1.2 formation was reversed by protamine only by 14% and 23% respectively. Our data do not support the concept that to reduce the incidence of protamine’s potential clinical side effects, the administration of a lower dose of protamine than 1 mg protamine/100 U UFH is justified. Furthermore, a significant residual impairment of hemostasis is still detectable after administration of the recommended dose of protamine to neutralize the anticoagulant effects of a LMWH preparation.
On the Role of C1-Inhibitor as Inhibitor of Tissue-type Plasminogen Activator in Human Plasma
Authors: Huisman L G M , van Griensven J M T , Kluft C
Published: July 2018

An enzyme immuno assay was developed to measure complexes of tissue-type plasminogen activator (t-PA) with C1-inhibitor in order to study the role of C1-inhibitor as an inhibitor of t-PA in plasma. In vitro experiments with melanoma and recombinant t-PA learned that purified C1-inhibitor reacts with both single chain t-PA and two chain t-PA. The rate constants ranged from 3.0 to 5.2 M-1s-1 In plasma, melanoma and recombinant two chain t-PA were hardly inhibited by C1-inhibitor, in contrast to melanoma and recombinant single chain t-PA which were inhibited to the same extent by endogenous C1-inhibitor as they were by purified C1-inhibitor. In vivo, t-PA/C1-inhibitor complex could be measured in plasma in a few cases in healthy volunteers (0.62 ± 0.43 ng/ml t-PA equivalents), after exercise (0.84 ± 0.25 ng/ml t-PA equivalents) and after a desmopressin infusion (0.26 ± 0.04 ng/ml t-PA equivalents). However, t-PA/C1-inhibitor complex was found in plasma in all cases after venous occlusion (1.7 ± 0.5 ng/ml t-PA equivalents), in peritoneal fluid from patients suffering from peritoneal inflammatory disease (2.2 ± 1.3 ng/ml t-PA equivalents) and in plasma from healthy volunteers during a t-PA infusion (27.7 ± 18.5 ng/ml t-PA equivalents at peak level). In the last case, about 8 % of the infused dose of recombinant t-PA (alteplase) was inhibited by C1-inhibitor at peak level. The half-life (t1/2α) of t-PA antigen in plasma was found not to be altered when t-PA was inhibited by C1-inhibitor (4.0 min and 4.2 min, respectively). Thus, in vivo, t-PA/C1-inhibitor complex is mostly present when t-PA escapes rapid liver clearance and accumulates in one place (e.g. during venous occlusion or in peritoneal fluid) or when it circulates in high concentrations (e.g. during t-PA infusion).
Comparison of the Effects of Anticardiolipin Antibodies from Patients with the Antiphospholipid Syndrome and with Syphilis on Platelet Activation and Aggregation
Authors: Campbell Andrew L , Pierangeli Silvia S , Wellhausen Samuel , Harris Nigel E
Published: July 2018

Anticardiolipin antibodies (aCL) are induced both in the Antiphospholipid Syndrome (APS) and syphilis, but thrombosis, thrombocytopenia, and pregnancy loss occur only in the APS. Differences in specificity and function of aCL antibodies might explain clinical differences between APS and syphilis. This study compared the effects on platelet activation and aggregation of affinity purified IgG anticardiolipin antibodies from 6 patients with the APS (IgG-APS) and 5 patients with syphilis (IgG-syph). Platelet aggregation was studied by aggregometry and platelet activation by flow cytometry. In the presence of low concentrations of thrombin, ADP, or collagen, all 6 IgG-APS samples induced platelet aggregation and activation, but none of the IgG-syph samples had this effect. In the absence of platelet agonists, only 3 of 6 IgG-APS caused platelet aggregation and none caused platelet activation; IgG-syph had no effect. The IgG-APS samples but not IgG-syph bound phosphatidylserine by ELISA. We conclude that polyclonal antibodies specific for phosphatidylserine may induce platelet activation and aggregation in the presence of low concentrations of platelet agonists.
Hypercoagulable State Indicates an Additional Risk Factor for Atherosclerosis in Werner’s Syndrome
Authors: Goto Makoto , Kato Yasukazu
Published: July 2018

To assess the risk factors for atherosclerosis in Werner’s syndrome (WS), coagulation/fibrinolytic system parameters and lipid levels were investigated in 9 non-smoker patients with WS and compared with normal control values (N). The levels of thrombin antithrombin III complex (p <0.05), D-dimer (p <0.05), tissue plasminogen activator (p <0.005) and PA inhibitor 1 (p <0.01) were significantly increased, while the level of thrombomodulin (p <0.005) in the fasting plasma was significantly decreased in the WS cases compared with N. Lipid profiles confirmed that 8 of the 9 patients were of hyperlipidemia type IIb, 7 had hyperinsulinemia and 5 fulfilled the criteria for clinical diabetes mellitus. The hypercoagulable condition suggested the existence of multiple risk factors for atherosclerosis in WS in addition to the previously reported hyperinsulinemia and hyperlipidemia.