bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE INFLUENCE OF L-LYSINE ON FACTOR VIII ELUTED FROM MATRIX BOUND DEXTRAN SULPHATE
Authors: Harrison P , Saundry R H , Savidge G F 
Published: June 2019

Factor VIII/vWF displays high affinity for matrix bound sulphate groups. Linear salt and pH gradient elution from Dextran Sulphate Sepharose at 4°C resulted in complete separation of the complex from major protein contaminants with typical yields of 70-90% vWF:Ag and vWF (RCoF). Elution in physiological calcium concentrations gave VIII and VIII:Ag yields of 35% and 65% respectively. Addition of L-Lysine (1.0M) to all buffers inhibited VIII/vWF binding, although lysine gradients (0-1.0M) gave comparable binding and elution profiles as C-1.0M NaCl, but with impaired resolution between protein moieties. However, in the presence of L-Lysine, yields of VIII and VIII:Ag were significantly improved to 80% and 100% respectively when assay standardizations with appropriate lysine concentrations were performed. Furthermore, the binding of fibrinogen could be inhibited by 0.15M L-Lysine, 0.075M NaCl in the equilibrating buffer.The presence of enzymic activity, as assessed by S-2222 and S-2238 in the eluting fractions could be abolished by the application of recryoprecipitated material pre-adsorbed with Al(OK)3 and celite. Incorporation of lysine to the buffers with the associated increase in yields further supports the potential viability of the separation principle for large scale purification of Factor VIII.
FACTOR IX CONCENTRATES ARE THROMBOGENIC AT HIGH DOSES IN DOGS
Authors: Ferguson J , Dawes J , Prowse C V , Foster P R , Feldman P A , Smith J K 
Published: June 2019

A canine model has recently been established to assess the potential thrombogenicity of intravenously infused blood products. Elevated plasma levels of fibrinopeptide A (FpA) were identified as the most sensitive indicator of a thrombogenic response, and this was the only parameter to change significantly when issued batches of factor IX (II + X) concentrate were infused at a dose of 100 iu/kg. After infusion of 200 iu/kg, however, plasma FpA concentrations and FDP titres rose, the APTT was prolonged, and the platelet count and fibrinogen level fell. At this dose, therefore, FIX concentrates which were not identified by in vitro tests as potentially thrombogenic induced a response when infused into dogs.A batch of FIX concentrate which failed the criteria for in vitro thrombogenicity and was therefore not issued for routine use was infused at 100 iu/kg. Plasma FpA levels rose as did the FDP titre, and fibrinogen concentrations fell, but the APTT was only slightly prolonged. The thrombogenic response to 200 iu/kg of issued FIX concentrate was at least as severe as that following infusion of 100 iu/kg of this rejected batch.Thus, there is a threshold dose of FIX concentrate above which a severe thrombogenic response can ensue, and the current in vitro tests may not be a reliable indicator of potential thrombogenicity when FIX concentrates are infused at high doses. This should be taken into account when administering unusually high doses, particularly to patients who may have reduced levels of circulating protease inhibitors.
IMPORTANCE OF LARGE VON WILLEBRAND FACTOR (vWF) MULTIMERS IN vWF INTERACTION WITH PLATELET GLYCOPROTEIN IIb/IIIa
Authors: Yamamoto M , Ando Y , Watanabe K , Iri H , Araki Y , Murata M , Murakami H , Satoh K , Ikeda Y 
Published: June 2019

Recently it has been reported that, in addition to binding to glycoprotein (GP) lb, vWF also interacts with GPIIb/IIIa, although the physiological relevance of this interaction is not completeley clear. In this paper, we have investigated the role of different size of vWF multimers in vWF-mediated platelet aggregation. Different size of vWF multimers were purified from human plasma through Sephacryl S-1000 column according to the method of Fowler et al. Fractions were analysed by SDS-agarose gel electrophoresis by the method of Ruggeri et al. When each fraction was examined for ristocetin cofactor activity (RCo), only larger multimers exhibited significant RCo. The maximum extent of ristocetin-induced platelet agglutination by larger multimers (10 μg/ml) was 80%, while that of intermediate and lower multimers at the same concentration was 20% and 0%, respectively. Each fraction was then added to washed platelet suspensions in the presence of 10 μM ADP and 0.3 mM CaCl2. Only larger multimers induced platelet aggregation, while intermediate and lower multimers failed to induce platelet aggregation. The maximum extent of aggregation in the presence of larger multimers (10 μg/ml) was 70% of that in the presence of fibrinogen instead. Similar experiments were peformed using platelet-rich plasma from a patient with afibrinogenemia in stead of washed normal platelets. ADP caused significant aggregation only when purified vWF larger multimers or fibrinogen was added. This vWF-mediated aggregation was completely inhibited by monoclonal antibody to GPIIb/IIIa (1 μg/ml) and synthetic peptide, Arg-Gly-Asp-Ser, (1 mM).Our results indicate that larger multimers of vWF play major roles in vWF interaction with GPIIb/IIIa.
STUDY OF IIA VON WILLEBRAND'S DISEASE (VWD) VARIANTS TO DETERMINE DEGREE AND TYPES OF HETEROGENEITY
Authors: Enayat S M , Hill F G H , Sultan Y , Williams C W 
Published: June 2019

Thirty four IIA vWD patients (16 from kindred I, 2 from kindred II and 17 unrelated patients) from 19 families were studied to compare multimer patterns using discontinuous SDS gel electrophoresis on a variety of agarose gels. Platelet multi-mers and effect of EDTA on plasma multimers were also studied in some.The large kindred and 9 other patients showed identical multimer and triplet abnormalities. The 11 other patients showed different multimer patterns either by having intermediate multimers or different triplet patterns. The second kindred had a similar triplet abnormality to kindred I but had intermediate multimers. Two other patients showed similar patterns except on 2% agarose gels when differences in the lowest multimer was seen. Of the 3 patients of YS, one showed the common IIA pattern but also had intermediate multimers, another had an unusually faint upper triplet band, while the third in addition to a faint upper triplet band with ESVWF 2+ had no identification of minor or major bands with ESVWF 10+ Another patient lacked high and some intermediate multimers but had a normal triplet pattern. The pattern we have seen in Kernoff's patient (1) still appears unique. In kindred II abnormal triplets persisted and high multimers appeared in EDTA plasma. In kindred I (and similar patients) intermediate multimers and a change in triplet pattern was observed in EDTA while lysed platelets showed an abnormal pattern different to the plasma one.This emphasizes the heterogeneity of IIA vWD and the need to consider multimer deletion, triplet pattern, platelet multimers, effect of EDTA in trying to subclassify in order to study structure function relationships of vWF.1. Kernoff PBA, Gruson R, Rizza CR. (1974) A variant of factor VIII related antigen. Br. J. Haematol. 26: 435.+ESVWF 2 and 10 are monoclonal antibodies to vWF epitopes.
BLEEDING TIME IN TREATED PATIENTS WITH SEVERE VON WILLEBRAND DISEASE IS NOT CORRECTED ONLY BY GIVING NORMAL MULTIMERIC PLASMA VON WILLEBRAND FACTOR
Authors: Mannucci P M , Moia M , Altieri D , Monteagudo J , Castillo R 
Published: June 2019

Even though it is generally held that cryoprecipitate (cryo) and fraction I-0 correct the prolonged bleeding time (BT) in patients with von Willebrand disease (VWD), perusal of reported data indicates that the correction is usually short lasting and often partial. We decided to do a controlled study of the relationship between the multimeric structure of von Willebrand factor (VWF) in 5 patients with severe VWD after infusion of three plasma concentrates : "wet" cryo, lyophilized (lyo) cryo, and fraction 1-0 given in random order. The dosage of concentrates was tailored to achieve post infusion levels of RiCof above the lower normal limit (50 U/dL) for at least 3 hours. The post-infusion BT values are shown in the table.These findings indicate that the attainment of a normal BT is the exception rather than the rule after infusion of three plasma fractions used for treatment of severe VWD. In all the concentrates the proportions of large VWF multimers, calculated by scanning the electrophoretic gels, were the same as in normal standard plasmas. An intact multimeric structure was recovered in post-infusion plasma of patients treated with wet cryo, whereas there was post infusion loss of large multimers after lyo and fraction I-O. In conclusion, an intact multimeric structure in post infusion plasmas is necessary but not sufficient to sustain a normal BT in VWD patients.
HETEROGENOUS RESPONSES TO CRYOPRECIPITATE AND DDAVP IN TYPE IIA VON WILLEBRAND'S DISEASE (VWD)
Authors: Chediak J , Maxey B , Eldridge J , Telfer M C 
Published: June 2019

Von Willebrand's disease is an autosomal dominant disorder characterized by excessive mucocutaneous bleeding, prolonged bleeding time (BT), and reduce amounts of ristocetin cofactor activity (RiCof). The Von Willebrand factor antigen (VWF:Ag) shows either reduced amounts or no multimers (Types I and III), or a selective reduction of high molecular weight multimers (HMW) (Type IIA and IIB). Variable responses to DDAVP have been reported in IIA VWD suggesting that IIA patients (pts) are a heterogenous group. Some IIA pts may show RiCcf activity after DDAVP infusion even though no HMW multimers are found.Von Willebrand factor antigen, RiCof and BT were analyzed in five pts (2 females and 3 males) known to have Type IIA VWD. Baseline values shov/ed marked reductions of RiCof (less than 13% of normal), BT greater than 15 minutes, faster immunoelectrophoresis of VWF:Ag and absent HMW multimers. Immunoelectrophoresis of VWF:Ag by the Laurell technique gave variable amounts ranging from 10 to 125% or normal. Three adult pts received DDAVP (Stimate) or cryoprecipitate (cryo) and the responses on abnormal parameters were assessed up to 48 hours. In two pts the BT corrected with cryo, whereas in the third patient the correction was minimal. The three pts showed a normal decay of both VWF:Ag or RiCof after cryo. However, after DDAVP the decay of VWF:Ag and RiCof was similar to that after cryo in one patient and more rapid in two patients.In these two patients, the data would be compatible with the rapid proteolysis of endogenoue VWF released by the patient's endothelial cells, whereas the exogenous VWF given as cryo showed normal survival in the patient's blood.
THE EFFECT OF EARLY BLOOD TRANSFUSION ON THE OUTCOME OF GASTROINTESTINAL HAEMORRHAGE
Authors: Blair S D , Javanvrin S B , McCollum C N , Greenhalgh R M 
Published: June 2019

It has been suggested that mortality due to upper gastrointestinal haemorrhage may be reduced by restricting blood transfusion [1], We have assessed whether this is due to an anticoagulant effect in a prospective randomised trial.One hundred patients with severe, acute gastrointestinal haemorrhage were randomised to receive either at least 2 units of blood during the first 24 hours of admission, or no blood unless their haemaglobin was lessthan 8g/dl or they were shocked. Minor bleeds and varices were excluded As hypercoagulation cannot be measured using conventional coagulation tests, fresh whole blood coagulation was measured by the Biobridge Impedance Clotting Time (ICT). Coagulation was assessed at 24 hour intervals and compared to age matched controls with the results expressed as mean ± sem.The ICT on admission for the transfusion group (n=50) was 3.2±0.2 mins compared to 10±0.2 mins in controls. This hyper-coagulable state was partially reversed to 6.4±0.3 mins at 24 hours (p<0.001). The 50 allocated to receive no blood had a similar ICT on admission of 4.4±0.4 mins but the hypercoagulable state was maintained with ICT at 24 hours of 4.320.4 mins. Only 2 patients not transfused rebled compared to 15 in the early transfusion group (p<0.001). Five patients died, and they were all in the early transfusion group.These findings show there is a hypercoagulable response to haemorrhage which is partially reversed by blood transfusion leading to rebleeding
KINETICS OF LOW MOLECULAR WEIGHT HEPARIN IN MAN DETERMINED BY PROTAMINE CHLORIDE
Authors: Bode V , Franz R , Welzel D , Wolf H , Harenberg C 
Published: June 2019

Low molecular weight (LMW) heparin is characterized by a higher affinity to antithrombin HI, less inhibition of thrombin and increased inhibition of factor Xa. The half life of the antifactor Xa activity of LMW heparin is doubled compared to normal heparin. However, these parameters reflect the pharmacodynamics rather than the kinetic of the compound. We, therefore, analyzed the kinetics of LMW heparin after i.v. injection in man using protamine chloride for gravimetric evaluation of LMW heparin in the plasma samples.Six healthy adults received 100 units per kg body weight normal heparin or 100 anti Xa units per kg LMW heparin (Sandoz AG, Niimberg, FRG). To serial samples of venous blood protamine chloride was added in serial dilutions until the thrombin inhibition was antagonized. Since factor Xa inhibition of LMW heparin cannot be abolished completely by protamine chloride, two amounts of protamine chloride were added to the plasma samples ex vivo, until factor Xa was inhibited up to 0,2 and 0,04 units/ml. The following maximal plasma concentrations (C max) and half lives (T/2) were calculated (average values):The pharmacokinetics of normal heparin show no differences on thrombin and factor Xa interaction. LMW heparin, however, interacts to 30 % with thrombin and to 100 % with factor Xa; the half life on factor Xa is twice as long as on thrombin; releases endogenous compounds with antifactor Xa activity, which are neutralized only hardly by protamine chloride;and these endogenous compounds mediate in part the longer half life.
A NEW MUCOPOLYSACCHARIDE FROM STICHPUS JAPONICUS(SEA CUCUMBER) AND ITS ANTICOAGULANT PRORETIES
Authors: Takamatsu J , Saito H , Kamiya T , Muranaka Y , Minami Y F , Fan H T 
Published: June 2019

A new mucopolysaccharide(FGAG) has been isolated from the cell wall of Stichopus japonicua. The molecular weight of FGAG is about 50,000. The component sugar of the FGAG are identified as galactosamine, glucuronic acid, fucose and sulfate with the molar ratioof 1:0.94:0.84:3.60,respectively. The anticoagulant effects of FGAG were studied. At low concentration(lμg/ml), FGAG completely inhibited the rabbit plateletaggregation induced by thrombin and prolonged thrombin time of not only human plasma but purified fibrinogen solution to a similar extent, suggesting that action of FGAG is not depend on plasma component(antithrombin III and/or Heparin c.ofactor II).After intravenous injection into rabbits(lmg/kg),significant prolongation of activated partial thromboplastin time(APTT) was observed. Although the in vivo antithrombin activity of the FGAG was weaker than that of heparin.it lasted longer than that of heparin and was not inhibited by platelet factor 4.These results suggested that FGAG is a new and unique mucopolysaccharide with antithrombin activity and may come into use for the treatment ofDiseminated Intravascular Coagulation.
THE ROLE OF Tc-99m RED BLOOD CELL (RBC) VENOGRAPHY IN PATIENTS WITH CLINICALLY SUSPECTED DEEP VEIN THROMBOSIS
Authors: Leclerc J R , Welfson T , Rush C , Lepanto L , Arzoumanian A , Raymond F , Rosenthall L 
Published: June 2019

Although it has been available for a number of years, Tc-99m RBC venography has never been evaluated in an epidemiological study. We have compared Tc-99m RBC venography to impedance plethysmography (IPG) in 113 consecutive eligible patients with clinically suspected first episode of deep vein thrombosis (DVT). IPG was performed at initial presentation (day 0) and RBC venography within the next 72 hours.RBC venography was performed by labelling in vitro 5ml of patients' red blood cell with 20 millicuries of Tc-99m. Patients with an initially abnormal IPG underwent contrast venography to rule out a falsely positive test result. Patients with an initially normal IPG had the test repeated at day 1, 3, 5 to 7 and 10 to 14. Anticoagulant treatment was witheld in all patients who remained normal by serial IPG testing. All patients underwent a 3 month follow-up period. RBC venography was considered abnormal if there was a 50% or greater decrease in isotope concentration in a deep vein compared to the same vein in the other leg. The sensitivity of RBC venography was 79% with 95% confidence limits (C. L.) from 59% to 92%. Specificity was 61% (95% C. L. from 51% to 71%). Positive and negative predictive values were 37% (95% C. L. from 25% to 51%) and 91% (95% C. L. from 81% to 96%) respectively. None of the patients who remained normal by serial IPG testing died from or had objectively documented venous thromboembolism during the follow-up period. We conclude that : 1)RBC venography is non-specific and, 2) a decision to treat should not be made on the basis of the results of this test alone in view of its low positive predictive value.
PRESENCE OF THE LUPUS ANTICOAGULANT IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS DOES NOT CAUSE INHIBITION OF PROSTACYCLIN PRODUCTION
Authors: Rustin M H A , Bull H A , Dowd P M , Isenberg D A , Snaith M L , Machin S J 
Published: June 2019

The cause of the thrombotic tendency in patients having the lupus anticoagulant (LA) is unknown. Since inhibition of prostacyclin production by endothelial cells (EC) may be a pathogenetic factor, the effect of sera from normal subjects (NS, n=9), SLE (systemic lupus erythematosus) + LA (n=9) and SLE-LA (n=13) on the production of PGI2 by cultured human EC was studied.Confluent 1° cultures of human umbilical vein EC were incubated with 1, 5, 10 and 20% sera from the above for 24 hours. After stimulation with thecalcium ionophore A23187, 6-keto-PGF1α(the stable metabolite of PGI2) in the supernatant was measured by radioimmunoassay.A dose dependent inhibition of 6-keto-PGF1α was observed with all the sera but only the 10 and 20% sera from patients with SLE-LA produced a significantly greater inhibition than control sera. The mean production of 6-keto-PGFia (ng/104 cells) was 2.278 (NS), 2.6594 (SLE-LA) and 2.1418 (SLE + LA)after incubation with 1% sera for 24 hours. This decreased to 1.3647, 0.6517 and 0.942 respectively following incubation with 20% sera. This represented a 44% (NS), 71% (SLE-LA) and 62% (SLE + LA) inhibition of 6-keto-PGF1α production compared to serum free media.The non-significant reduction in prostacyclin production by sera from patients with SLE and the lupus anticoagulant suggests that other factors are responsible for the thrombotic tendency in these patients.
IN VIVO AND IN VITRO NEUTRALIZATION OF BACTERIAL TOXINES BY IGM ENRICHED AND CONVENTIONAL I. V. IMMUNOGLOBULINS
Authors: Dichtelmuller H , Stephan W 
Published: June 2019

Severe septic phenomena are caused bybacterial toxins. We therefore investigated the neutralization of toxins derived from Staphylococcus aureus and Pseudcmonas aeruginosa by different i.v. irtmunoglobulin preparations using hemolysis inhibition tests and mouse protection tests. The efficacy of conventional i.v. immunoglobulin containing preparations were compared with an IgM enriched i.v. immunoglobulin (Pentaglobin).For hemolysis inhibition tests sterile filtered supernatant of Staphylococcusaureus was prepared and given to human erythrocytes. When IgM enriched immunoglobulin was added, toxin depended hemolysis was inhibited. By addition of three different i.v. immunoglobulin preparationsno inhibition of hemolysis was observed. In order to confirm these results in vivo, mice were exposed to the toxic supernatant of Staphylococcus aureus intraperitoneally and treated with i.v. immunoglobulins (3.1 mg/animal) 30 min after toxin exposure. Significant protection of toxin exposed animals was achieved by IgM enriched i.v. immunoglobulin (92 % protection) but not by conventional i.v. immunoglobulin (17 % protection). Similar results were obtained when mice were exposed to toxic supernatant of Pseudcmonas aeruginosa instead of Staphylococcus aureus. We therefore conclude, that IgM is essential for neutralization of bacterial toxins and IgM enriched i.v. immunoglobulins are more effective in therapy of severe septic phenomena, compared to conventional i.v. immunoglobulins.
PERNATAL MANAGEMENT OF FETAL THROMBOCYTOPENIA
Authors: Daffos F , Forestier F , Kaplan C , Muller J Y 
Published: June 2019

Fetal thrombocytopenia resulting from alloimmunisation (NAIT] or from autoimmune pathology (ITP) may contribute to morbidity from hemorrhage particularly when bleeding occurs into the central nervous system.Utilizing a safe procedure for in utero blood samplings i.e. directpuncture under ultrasound guidance, we are able to propose a prenatal management. Considering NAIT we haveuntil now treated 6 patients. We propose a screening protocol for highrisk group based on maternal antecedents and immunological grounds. Fetal blood sampling is performed at 20th week of gestation allowing platelet count and typing. If there isincompatibility between the fetus and his mother two ways can be consFdered : absence or presence of thrombocytopenia. If the platelet countis normal, nothing is done until 37th week of gestation. In the other case, frequent ultrasound examinations are done. At the 37e week, a fetal blood sampling is performed andin utero maternal platelet transfusion is done in the case of thrombocytopenia, before the delivery. It is possible with this prenatal treatment to have vaginal delivery. Considering ITP. when the maternal status permit it. fetal blood samplingslet us to know exactly the fetal platelet count. By this way. the indication of delivery can be documented.This procedure offers a new possibility of easily taking iterative samples. until the end of pregnancyand represents a particular interest in the prenatal treatment of suchhemorrhagic disorders.
LEVELS OF TOTAL AND FREE PROTEIN S DURING NORMAL AND PATHOLOGICAL PREGNANCY AND IN POST-PARTUM
Authors: GRUEL Y , MOALIC P , DUROUCHET E , GUEROIS C , DELAHOUSSE B , LEROY J 
Published: June 2019

Levels of total and free Protein S (PS) were measured on plasmas from 28 women during normal (n = 15, mean age = 25) and pathological pregnancy (Hypertension or preeclampsia, n = 13, mean age = 27). Prepartum (PreP) samples were obtained in the third trimester between the 30th and the 40th weeks of gestation, and postpartum (PostP) blood collected in the 5 days after delivery. Total PS level was determined using Laurel 1 rocket immunoelectrophoresis (Diagnostica Stago, Asnifcres-France). Free PS was measured using the same method after precipitation of C4b-BP-Bound-PS by polyethylene glycol. C4b-Binding Protein (C4b-BP) determinations were conducted by Laurel 1 method as well. Results were expressed as a percentage (Mean ± SD) of a normal adult pool (n = 15).A significant decrease of free PS level was observed both in normal or pathological pregnancy and in postpartum. These data might be explained, by the increase of C4b-BP plasmatic level.*= p<0.05 (as compared to normal controls), **= p<0.01, ***= p<0.001 (Student´s t test).