bluuebunny/crossref_metadata_2025_split huggingface dataset:
LIFE-EXPECTANCY OF DUTCH HEMOPHILIACS, 1972-1985
Authors: Rosendaal F , Smit C , Varekamp I , Bröcker-Vriends A , Suurmeijer T , Briít E 
Published: June 2019

The 1ife-expectancy of hemophiliacs has risen during the last decades from (for severe hemophilia) a mere 16 yrs in 1940, 23 yrs in 1964 to almost normal after coagulation factor preparations became available. Still, many hemophiliacs encounter ratings or refusals when applying for life-insurance.We carried out three mail surveys (1972, 1978, 1985) among Dutch hemophiliacs to establish excess mortality caused by hemophilia. Follow-up for non-respondents was carried out with help from the municipal authorities, while information on the deceased was obtained from the hemophilia treatment centers. To compare mortality with the general population, we constructed Kaplan-Meier reference curves for population groups with the same age and sex distribution, using national death tables. Pending completion of the follow-up for the 1972-1985 interval, this abstract supplies the results for the 1978-1985 period.The 1978 cohort included 578 individuals, with a mean age of 26 yrs (general male population: 33 yrs). None were lost to follow-up, 22 (3.8%) had died during the 7i yrs of observation. In the reference group 1.9% mortality would have been expected. So, overall relative mortality is increased twofold compared to the general male population (95% confidence interval 1.3-3.0). Patients with an inhibitor excluded, excess mortality did not differ much for severe, moderate and mild hemophilia (relative mortality: 2.3, 1.8, 1.5). In 11 cases hemorrhage was the cause of death, but in 6 cases this was associated with an underlying lethal disorder. In 9 cases the cause of death was not related to hemophilia and in 2 it remained unknown. An inhibitor was present in 4 (18%) of these 22 patients, but in only 4% of the total group of 578. In the 1972 survey 43% of the respondents who had applied for a life-insurance (n=199) reported a rating or a refusal, in 1978 47% of 227 and in 1985 53% of 676.The excess mortality caused by hemophilia is small and similar to that due to smoking cigarettes. Moreover, the excess may be caused in part by a carry-over effect from the time before modern treatment was introduced.
TWO FVIII GENE LESIONS DETECTED IN SEVERE AND MODERATE HAEMOPHILIA A
Authors: Bertagnolo V , Volinia S , Legnani C , Rodorigo G , De Rosa V De , Bernardi F 
Published: June 2019

DNAs from 15 haemophilia A patients from different families have been hybridized to FVIII cDNA probes for the exons 14-26.In a severely affected patient (FVIII:C 2 %) the TaqI site of exon 24 is absent originating an abnormal band of 4.2 Kb. A C toT transition in the CG dinucleotide of the TaqI site (TCGA) is the probable gene mutation. Since the transition in the sense strand should originate an additional Hind III site, which is not detected in our patient, we infer that the mutation occurred in the antisensestrand causing an aminoacid change (CGA →CAA, Arg → Gin). This isin accordance with the low activity of FVIII and with the absence of inhibitor. Infact Gitschier et Al reported in a patient with ahigh titre of anti-FVIII antibody and with <1% FVIII activity a C → T transition in the coding strand, originating a nonsense codon in the TaqI site of exon 24.In the Hindlll pattern from a moderately affected patient (FVIII:C 4%) the fragment containing the exon 18 is 2.5 Kb in size (normal 2.6 Kb). Since the patterns with other restriction enzymes are indistinguishable from normal a small mutation originating a new Hind III site is likely. Both altered patterns have been detected in the patients' mothers.Work supported by Ricerca Sanitaria Finalizzata Regione Emilia Romagna
THE ISOLATION OF COAGULATION FACTOR VIII FROM HUMAN BLOOD PLASMA BY AFFINITY CHROMATOGRAPHY
Authors: Riethorst W , te Booy M W P M , Beugeling T , Bantjes A , Over J , van Aken W G 
Published: June 2019

The need for high quality concentrates of coagulation factor VIII (FVIII:C) for treatment of haemophilia A is increasing. As the purity of FVIII:C obtained with existing large scale methods is poor and yields are low, another method for the isolation of FVIII is being developed primarily to avoid losses incurred during cryoprecipitation.Affinity gels were prepared by derivatizing Sepharose CL 4B with different positively charged ligand-spacer combinations. The adsorption of FVIII as well as the von Willebrand factor (VWF) from human blood plasma onto these gels was measured by a one-stage assay for FVIII:C, and enzyme immuno assays (ELISA) for FVIII:CAG and VWF:AG using monoclonal antibodies. The influences of pH, conductivity, ligand density, geltplasma ratio, and length and composition of the spacer as well as the adsorption kinetics were studied to obtain information about the types of interactions responsible for bonding of FVIII to the gels. A combination of at least electrostatic and hydrophobic interactions was concluded to play a role in most cases.At optimal conditions more than 90 % of FVIII could be adsorbed batch-wise from plasma at room temperature in less than one hour with a gel:plasma ratio of 1:20 (i.e. 2.5 g dried gel/1 plasma). In different runs 65-75 % of the FVIII:C applied was recovered by column-wise elution with a salt gradient. The eluate contained less than 0.34 % of the protein applied, which implies that FVIII was purified 190 times. Using fresh-frozen plasma (0.8 IU FVIII/ml) as a starting material for this one-step procedure the final specific activity was 2.3 IU/mg, which is significantly better than that obtained for FVIII isolated by cryoprecipitation. Furthermore, the F. VIII:C to VWF ratio in the eluate was approximately 1:1. The isolated FVIII:C was stable at room temperature and the supernatant plasma appears suitable for further fractionation. It is concluded that this method is worth scaling up and its use for purification of FVIII from other sources is anticipated.
IMMUNOPURIFICATI0N OF FVIII/vWF FROM PLASMA
Authors: MEJAN O , DELEZAY M , FERT V , CHEBALLAH R , BOURGOIS A 
Published: June 2019

At present, antihemophilic factor concentrates available for hemophilia A therapy raise some problems :- weak recovery of FVIIIC (20 to 25%)- specific activity generaly lower than 5IU/mg- loss of a large part of the von Willebrand factor, carrier of the FVIIIC- necessity to inactivate viral contaminants by treatments which induce a decrease in FVIII recovery. To solve these difficulties, an immunopurification process has been developed directly from plasma. A mouse monoclonal antibody (MAb) toward vWF, able to bind the FVIII/vWF complex under physiologic conditions and to release it in a suitable elution buffer preserving the FVIIIC activity has been selected. MAb coupling chemistry on gel beads has been optimised. The immunopurification process developed allows to treat 12 to 19 Liters of plasma with one gram of antibody in each cycle (i.e. 6h.). Immunoadsorbant can be used during 10 cycles with standard quality plasma and with an average recovery of 50% for FVIIIC. This process warrants an important elimination of contaminant virus (104 for HBs) an a release of the mouse MAb in purified FVIII lower than 10-9 M . These properties could justify an industrial application of this immunopurification process to produce therapeutic hemophilia A fractions.
CLOTTING FACTOR DEPENDENCY OF PROTHROMBINASE ACTIVITY IN DICOUMAROL PLASMA. THE IMPORTANCE OF A FACTOR IX DEPENDENT PATHWAY IN EXTRINSIC COAGULATION
Authors: Xi Ma , Béguin S , Hemker H C , Devilée P P 
Published: June 2019

We determined the generation of prothrombinase activity in plasma using a mathematical analysis of the thrombin generation curve (H. C. Hemker, G. M. Willems, S. Béguin. Thromb. Haemostas. 56, 9-17, 1986).Addition of the purified factor VII, IX or X to plasma from deeply anticoagulated patients (<15% level >10%) did not influence the rate and amount of prothrombinase formed. Only the amount of prothrombin in the starting plasma determined the course of thrombin generation. Adding increasing amounts of purified human clotting factor preparations to deficient plasmas showed that the treshold concentration under which factor VII, and IX start to have an effect on prothrombinase activity are 5% or lower. For factor X it is lower than 10%.From this it can be concluded that only the changes in prothrombin level must be held responsible for the anti thrombotic effect of oral anticoagulation. These conclusions are not modified if different types and concentrations of thromboplastin are used.We were able to show that at dilutions of human brain thromboplastin higher than 1:50, a factor IX and factor VIII dependent pathway plays an increasingly important role. This directly demonstrates the Josso pathway. The concentration of factor IX necessary for full activity is again <5%.We conclude that the antithrombotic effect of oral anticoagulant treatment, if it is mediated via the coagulation system, works via modification of the prothrombin level only.
ASIALO VON WILLEBRAND FACTOR ENHANCES PLATELET ADHESION TO VASCULAR SUBENDOTHELIUM
Authors: Ordinas A , Bastida E , Garrido M , Monteagudo J , de Marco L , Castillo R 
Published: June 2019

Native Von Willebrand factor (NvWF) binds to platelets activated by thrombin, ADP or ristocetin, and also supports the adhesion of platelets to subendothelium at high shear rates. In contrast, asialo von Willebrand factor (AvWF) induces platelet aggregation in absence of platelet activators. We investigated the role of AvWF in supporting the adhesion of platelets to rabbit vessel subendothelium under flow conditions at a shear rate of 2000 sec-1 for 5 min using the Baumgartner perfusion system. We also studied the effects of blockage of platelet GPIb or GPIIb/IIIa on platelet adhesion using monoclonal antibodies (Mabs),and we measured the rate of binding of 111I-labeled NvWF and AvWF to subendothelium. Perfusates consisted of washed platelts and red cells resuspended in a 4% human albumin solution to which increasing concentrations of NvWF or AvWF had been added. Platelets interacting with the perfused vessels were evaluated morphometrically using a computerized system. At a concentration of 1.2 /ig/ml the percentage of total coverage surface was 21.3 ± 4.8% and 40.0±14.6%, for NvWF and AvWF, respectively (p<0.01). Addition of either Mab against GPIb (LJlbl) or against GPIIb/IIIa (CP8) to the perfusates, reduced platelet deposition (p <0.01). The rates of binding of 111I-labeled NvWF and AvWF to perfused vessel subendothelium were similar (0.83±0.1μg and 0.95±0.1 μg ,respectively).Our results indicate that AvWF enhances the interaction of washed platelets with the vessel subendothelium under flow conditions. Furthermore, they suggest that this effect is related to the interaction of AvWF with platelets and not to an increased affinity of AvWF for subendothelium.
DDAVP IN DIABETES INSIPIDUS
Authors: Vicente V , Corrales J , Miralles J , Alberca I 
Published: June 2019

In order to investigate whether the response of von Willebrand factor (vWF), Factor VIII (FVIII) and tissue plasminogen activator (t-PA) to DDAVP infusion is governed by the integrity of the hypothaLamo neurohypophyseal axis, we studied the behaviours >of these proteins (FVIII, one stage; vWF antigen by electroimmunoassay and t-PA was measured in the plasma auglobulin fraction with added C-1 inactivator on fibrin plates) after DDAVP infusion (0.3 ug/Kg) in five patients with cranial diabetes insipidus, comparing them with the responses obtained in six healthy subjects.In spite of receiving a daily therapeutic dose of 10-20 ug of DDAVP the patients with diabetes insipidus showed normal basal levels of FVIII, vWF and t-PA. The increase in these parameters following DDAVP infusion were not significantly different in the two groups. These findings suggest that the integrity of the hypothalamo-hypophyseal axis is not neccessary for a response by vWF, FVIII and t-PA to occur after DDAVP infusion.
EFFECTS OF DDAVP AT COAGULATION AND FIBRINOLYTIC LEVELS : DIFFERENT MECHANISMS OF ACT ION-AN EXPERIMENTAL STUDY IN THE DOG
Authors: Pina-Cabral J M , Cunha-Monteiro A , Sousa-Dias M C , Agular-Andrade J 
Published: June 2019

After the injection of DDAVP in 39 non-anesthezised dogs (0.4 μg/kg) there was an average increase of factor VIII:C activity up to 145% (p<0.0001) and of fibrinolytic potential of euglobulin precipitate (t-PA) up to 196% (p<0.0001). The injection of DDAVP was repeated in each dog of a group of good responder animals at weekly intervals , but after : -A) Pentobarbital anesthesia (30 mg/kg)- the increase of factor VIILC was reduced from 164% to 116% (n=11; p<0.0005) and the increase in t-PA was reduced from 270% to 192% (n-11; p<0.05). -B) Injection of propranolol (tmq/kq) - the increase of factor VIILC was reduced from 167% to 110% (n=13; p<0.0005) and there was no decrease of fibrinolytic activity, (n-13; n.s.). -C) Splenectomv-the increase of factor VIILC was reduced from 166% to 122% (n=10; p<0.0005) and t-PA was increased from 196% to 256% (n=9; n.s.). There were no statistical significant differences in factor VIILC and fibrinolytic activities after repeating only the injection of DDAVP three times in the same animal at weekly intervals (n=5; n.s.).We conclude that the increase in F. VIII:C and fibrinolytic activities observed after DDAVP infusion are due to different mechanisms of action. On the one hand, pentobarbital anaesthesia reduced the increase of factor VIILC and t-PA , but on the other hand , beta-blockade and splenectomy influenced differently the behaviour of both biological activities.
DIFFERENTIAL CHANGESOF PLASMATIC MARKERS OF THE ENDOTHELIAL FOLLOWING dDAVP
Authors: Scrobohaci M L , Drouet L , Baudin B , Rodriguez A 
Published: June 2019

Plasmatic levels of tissue plasminogen activation is commonly assumed to be of endothelial origin ; Angiotensin converting enzyme can be of endothelial or monocytic origin;Fibronectin is mostly from hepatic origin but endothelium can participate. Protein S is a newly recognized endothelial protein. Plasmatic von Willebrand factor is mostly from endothelial origin as the factor megakaryocytic origin is stored in platelet αd granules.dDAVP by indirect effect stimulates release of endothelial factors,13 patients with moderate von Willebrand disease were submitted to an infusion of 0.4 ug/kg dDAVP and were followed for four hours after infusion.Interstingly the kinetics of release of each of the studied factors is totally different.-Tissue plasminogen activator israpidly released and come back alsoquickly to its original level,- Release of von Willebrand factor is delayed comparatively to tPA and stayed for a longer time at increased level,- Angiotensin converting enzyme is not affected by dDAVP while its level is stimulated by veno-occlusion- Fibronectin and Protein S arenot significantly modified by dDAVPFrom these results mechanism of action of dDAVP cannot be hypothesized, but it seems evident that the release (and so the endothelial metabolism) of each of the studied factorsis different and not linked.
INACTIVATION OF VIRUSES IN PLASMA ON TREATMENT WITH TRI(N-BUTYL) PHOSPHATE (TNBP) DETERGENT MIXTURES
Authors: Piët M P J , Chin S , Prince A M , Horowitz B 
Published: June 2019

Treatment of plasma with organic solvent/ detergent mixtures at the time of plasma collection or plasma pooling could reduce the exposure of technical staff to infectious virus and enhance the viral safety of final product. Treatment of plasma for 4 hours with 2% TNBP at 37°C or with 1% TNBP and 1% Tween 80 or Triton X-45 at 30°C resulted in the rapid and complete inactivation of ≥104 tissueculture infectious doses (TCID-50) ofvesicularstomatitis and Sindbis viruses, used as surrogates. TNBP and TNBP/Tween treatment of plasma was shown to inactivate ≥104 TCID-50 of human immunodeficiency virus. TNBPtreatment of plasma contaminated with 106 chimpanzee infectious doses (CID-50) of HBV and 105 CID-50 of NANBHV prevented the transmission of hepatitisto chimpanzees through 6 months follow-up.Immediately following treatment with 2% TNBP, the recovery of AHF, factor IX, factor V, and antithrombin IIIwas 75%,90%, 65% and 100%,respectively. A ⊕90% recovery of AHF was observed with TNBP/detergent mixtures. Treated plasma was fractionated intoAHF and prothrombin complex concentrates, immune globulin, and albumin by published techniques. Prior treatmentwithTNBP or TNBP and detergent did not affect the separations of desired proteins. Therefore, it appears possible to inactivate viruses in plasma prior to execution of standard fractionation procedures. If desirable, products prepared from TNBP-treated plasmacan be subjected to additional procedures to further insure virus safety.
EFFICIENCY OF STEAM TREATMENT PROCEDURES USED FOR VIRUS INACTIVATION IN HUMAN COAGULATION FACTORS
Authors: Barrett P N , Wöber G , Eibl J , Dorner F 
Published: June 2019

The transmission of viral agents from blood products derived from humanplasma has long been a serious healthproblem for the recipients. The majoragents involved are HBV, nonA nonB, Delta agent and HIV (LAV/HTLV-III). Wehave attempted to design product-specific viral inactivation procedures toprevent such transmission in blood products. Experiments were carried out with HIV, which is the only one of the above viruses which can be propagated and titrated in cell culture, and with a wide range of model viruses. High titre virus was added to blood products, and they were then subjected to different virus inactivation procedures.Heat treatment was carried out in aqueous solution with and without protein-stabilising agents, and it was demonstrated that such agents added toprevent loss of biological activity of blood products also resulted in a stabilisation of contaminating viruses.Therefore steam treatment inactivation procedures have been developed without the addition of such agents. Steam pressure, temperature and time of inactivation are the main variablesand these can be altered for each product to achieve an optimal balance between the degree of virus inactivation and retention of biological activity.It has been shown that each of thedifferent product-specific treatment procedures has a high HIV inactivation capacity.Studies with various model virusesalso demonstrated that the efficiencyof these procedures could be furtherimproved if necessary by altering various parameters such as steam pressure.
QUALITY ASSURANCE OF THERAPEUTIC HEPARIN/ORAL ANTICOAGULANT THERAPY IN A GENERAL TEACHING HOSPITAL
Authors: Brien W , Inwood M , Dillon K 
Published: June 2019

In preparation for the development of a standard anticoagulation protocol and as part of a quality assurance programme, a retrospective analysis of anticoagulation therapy in a teaching hospital was undertaken. The results of this audit were compared to the results of other workers who have previously emphasized controversial areas of anticoagulation therapy and potential benefits of a standard anticoagulation protocol.Charts from seventy-nine patients with a diagnosis of venous thrombosis were analyzed. Fifty-five percent of the patients were at increased risk of bleeding and forty-five percent had an extensive proximal vein thrombosis, but not apparent consideration of a heparin dose adjustment was noted. Patients received heparin for an average 9.7 days, with concomitant coumadin therapy for an average 4.8 days. Patients on heparin were over/ or undercoagulated on average 5.4 days and ninety-four percent of patients on coumadin had a PT (rabbit brain) greater than 18 seconds for at least one day. Sixty percent of patients had their dose changes noted in a tabular form for easy reference. Less than fifty percent had their hemoglobin or platelet counts followed while on heparin. The APTT and TCT are used to follow heparin therapy and discrepant results were noted in thirty-three percent. All patients' discrepancies were investigated automatically by the coagulation laboratory. Less than thirty percent of patients received formal teaching from the clinical pharmacist concerning coumadin therapy.We feel that these results show a need for a standard protocol for heparin coumadin therapy. It has been shown that a standard protocol favourable chemical, financial and therapeutic benefits
PHARMACOKINETIC BEHAVIOUR OF ANTITHROMBOTIC AND BLEEDING ENHANCING EFFECTS OF VARIOUS HEPARIN(OID)S IN RATS: THEIR RELATION WITH INTERACTIONS WITH FACTORS IIa AND Xa
Authors: Hobblen P M J , Vogel G MT , Meuleman D G 
Published: June 2019

The effects on thrombus formation and bleeding of various heparin(oid)s were studied at several time-intervals: in addition, the αXa-, αiia-, and thrombin generation inhibitory (IIaGI)-activities were measured amidolytically in plasma from these animals. The following substances were studied: heparin (HEP), the fraction of heparin with high affinity for ATIII (HA-HEP), a low molecular weight fraction of heparin (LMW-HEP), nitrous acid degraded heparin (NAD-HEP), FragrainR (FRA), Org 10172 and the fraction of Org 10172 with high affinity for ATIII (HA-10172). The substances were given in a dose of 800 αXa U/kg i.v. in the thrombosis model and in the double dose (1600 αXa U/kg i.v.) in the bleeding model because of the lower intrinsic effect on bleeding. The initial magnitude and the duration of the anti-thrombotic and bleeding enhancing effects of these substances are summarized in the table together with the half-lives of the αXa-, αia- and IIaGI-activities. NE: not estimated due to too low alla-activities.The following conclusions could be drawn concerning the duration of the effects: 1. in contrast with HEP most lower molecular weight substances showed different time courses of the anti-thrombotic and the bleeding enhancing effect 2. the duration of the antithrombotic effect of Org 10172 and HA-10172 is considerably longer than that of the other substances 3. the duration of the bleeding enhancing effect of Org 10172, HA-10172, NAD-HEP and FragminR is shorter than that of HEP, HA-HEP and LMW-HEP. Additional conclusions could be drawn by inspecting the time response curves and taking the magnitude of the effects into account: 4. Org 10172 and its high affinity fraction have a better benefit/risk ratio in comparison with the other substances, which even increases in time 5. the time-response curves of the anti-thrombotic effects seem to be associated with those of the aXa-activities and 6. the time-response curves of the bleeding enhancing effects seem to be related to those of thrombin inactivation.
BLEEDING EFFECTS ASSOCIATED WITH HEPARIN contaminants
Authors: Pangrazzl J , Oreste P , Torri G , Maggi A , Donati M B , Casu B 
Published: June 2019

Clinical use of heparin as an antithrombotic drug Is limited by the risk of excessive bleeding, generally ascribed to the anticoagulant activity of this mucopolysaccharide.Unexpectedly, some low molecular weight heparins with reduced anticoagulant activity are reported to cause bleeding in clinical and experimental studies. To approach this problem, a number of heparin preparations with various molecular weights were characterized by analysis of their 13C-NMR spectra. The bleeding potential of the same heparins was tested by measuring the "template" bleeding time (BT, a method exploring the mechanisms of primary haemostasis) in the rat tail, 15 min after i.v. administration of 0.75 mg/kg b.w. of the drug.Besides major NMR signals associated with known units of the regular and irregular regions of heparins, some of the preparations display 13C-NMR "extra-signals", which have a higher degree of relative intensity in the spectra of samples with higher haemorrhagic potential; indeed, all the samples exceeding in "extrasignals" a conventional intensity level of 2 had at least 70% prolongation of the BT over controls.These results suggest that specific contaminants, responsible for these13C-NMR "extra-signals", may also be responsible for the unusually high bleeding expressed by some heparin preparations. Work is in progress to identify these components and to evaluate which mechanism of primary haemostasis is involved in their haemorrhagic effect.