bluuebunny/crossref_metadata_2025_split huggingface dataset:
Platelet Aggregation and Plasma Lipoproteins in Alcoholics During Alcohol Withdrawal
Authors: Desai K , Owen J S , Wilson D T , Hutton R A 
Published: July 2018

SummaryPlatelet aggregation, platelet lipid composition and plasma lipoprotein concentrations were measured each week in a group of seventeen alcoholics, without overt liver disease, for one month, following acute, total alcohol withdrawal. The platelets were initially hypoaggregable but, within 1-2 weeks of cessation of drinking, they became hyperaggregable and then gradually returned towards normal values. Hyperaggregability could not be explained by increases in either the cholesterol or the arachidonic acid content of the platelets. Plasma very-low-density lipoprotein cholesterol levels remained high throughout the study, but the initially raised levels of high-density lipoprotein (HDL) cholesterol fell by 26%. Low-density lipoprotein (LDL) cholesterol concentration rose by 10% after two weeks of withdrawal but then returned to about the starting level. The resulting changes in the plasma LDL-cholesterol: HDL-cholesterol ratio, which had increased by more than 50% after two weeks of abstinence, essentially paralleled the time course of enhanced platelet reactivity in all but four of the alcoholics. These findings suggest that alterations in plasma lipoprotein concentrations during acute alcohol withdrawal may be a contributory factor to the haemostatic disorders present in such patients.
Immunological Relationship Between the Fast-Acting Plasminogen Activator Inhibitors from Plasma, Blood Platelets and Endothelial Cells Demonstrated with a Monoclonal Antibody Against an Inhibitor from Placenta
Authors: Philips M , Juul Anne-Grethe , Thorsen S , Selmer J , Zeuthen J 
Published: July 2018

SummaryTwo plasminogen activator inhibitors (I and II) were demonstrated in human placenta. The complex between inhibitor I and tissue-type plasminogen activator was purified by immunoadsorption to solid-phase anti-activator antibodies. The purified complex (Mr 95.000) was used for immunization of mice and subsequent production of monoclonal antibodies. One antibody (F37), which reacted with both free and complex-bound inhibitor I, was used for further study by a method involving binding of the antibody to protein A-Sepharose, immunoadsorp-tion of antigen and analysis of the resulting supernatant by SDS-polyacrylamide gel electrophoresis and enzymography. The analysis showed that F37 reacted with the fast-acting plasminogen activator inhibitors recently demonstrated in plasma, blood platelets and endothelial cells, indicating that these inhibitors and inhibitor I share a common epitope. Inhibitor II did not react with F37. Inhibitor II is identical to the placenta inhibitor previously described by others. It reacted selectively with polyclonal antibodies against that inhibitor.
Vitamin K Antagonism of Coumarin Intoxication in the Rat
Authors: Wallin R , Susan D , Patrick D , Ballard J O 
Published: July 2018

SummaryAn in vitro system which expresses all enzyme activities related to vitamin K-dependent carboxylation of blood clotting factors was prepared from livers of rats overdosed with warfarin, difenacoum and dicumarol respectively. In this system, the activities of the two pathways that are known to produce active reduced vitamin K1 cofactor for the carboxylation reaction were measured. Also the ability of high concentrations of vitamin Kx to overcome inhibition of clotting factor synthesis was studied. In the systems prepared from livers of warfarin and difenacoum intoxicated rats, pathway I was inactive. Vitamin K epoxide reductase was also inactive which strongly suggests that this enzyme catalyzes the activity of pathway I in vivo. Reduction of vitamin by pathway II bypassed the inactive pathway I and resulted in carboxylation activity. This pathway therefore mediates the antidotic effect of vitamin K1 in the coumarin intoxicated liver. In the in vitro system prepared from dicumarol intoxicated livers the activity of pathway I was not significantly affected. Dicumarol however was a strong inhibitor when added to liver microsomes in vitro.
Electroblot and Immunoperoxidase Staining for Rapid Screening of the Abnormalities of the Multimeric Structure of von Willebrand Factor in von Willebrand’s Disease
Authors: Lombardi Rossana , Gelfi Cecilia , Righetti P G , Lattuada Antonella , Mannucci P M 
Published: July 2018

SummaryA new electrophoretic method is described for rapid screening of abnormalities of the multimeric structure of von Willebrand factor in von Willebrand’s disease. The method is based on the transfer of the separated proteins from agarose gels onto nitrocellulose foils followed by immunoperoxidase staining. It has the advantage of not requiring radio-iodinated antibodies and reduces the working time for the entire procedure from 5-6 days to 3 days. Electroblotting followed by immunoperoxidase staining differentiates patients with intact multimeric structure from those without intermediate and/or large multimers. The more subtle defects of the inner structure of the smallest multimers found in patients with type II von Willebrand’s disease can also be identified. A potential disadvantage of electroblotting and immunoperoxidase staining is the lesser sensitivity of this technique, which results in the detection of a smaller number of multimers (11-12 bands) than by autoradiography without transfer onto nitrocellulose (16-17 bands).
Visualization of von Willebrand Factor Multimers by Immunoenzymatic Stain Using Avidin-Biotin Peroxidase Complex
Authors: Aihara M , Sawada Y , Ueno K , Morimoto S , Yoshida Y , Serres M de , Copper H A , Wegner R H 
Published: July 2018

SummaryA technique for the detection of von Willebrand factor multimers separated by discontinuous SDS agarose electrophoresis has been developed using non-radioactive com-v pounds. The multimeric patterns were visualized by monospecific anti-human vWF:Ag followed by incubation with biotinylated antibody. After addition of avidin-biotin-peroxidase complex, the peroxidase activitiy was detected by 4-chloro-l-naphthol, giving sharp bands with a clear background.By this method, the differences of vWF : Ag multimers could be easily observed between normal plasma and the plasmas from variant type vWD (IIA, IIB, platelet-type). Large and intermediate multimers were absent in the plasma with vWD type IIA, while only large multimers were absent in the plasma with vWD IIB and platelet-type. The absence of large multimers was also observed in two commercial F VIII preparations having the ratio of vWF/vWF : Ag 0.18 and 0.63. The preparation with the ratio of 0.63 showed the presence of larger intermediate multimers.Electrophoresis in SDS 1.5% agarose gel revealed triplet structure of each small multimer, and a relative increase of the smallest subband was observed in vWD IIA plasma, platelet-type vWD plasma and commercial F VIII preparations.The procedures described are easy and safe to perform and are useful for screening or classifying cases with vWD in general laboratories.
Blood Platelet Plasminogen Activator Inhibitor: Two Different Pools of Endothelial Cell Type Plasminogen Activator Inhibitor in Human Blood
Authors: Sprengers E D , Akkerman J W N , Jansen B G 
Published: July 2018

SummaryAn assay for plasminogen activator inhibitor in human platelets is described. With this assay we find an average value of 6.8 × 10−8 IU/platelet (S.D. = 3.0 × 10−8; n = 20) in a healthy population. We characterized the PA-inhibitor from platelets and identified it as endothelial cell type plasminogen activator inhibitor, by its immunologic and functional properties. Besides the plasma pool of plasminogen activator inhibitor with a very high turnover rate, platelets constitute a second pool of plasminogen activator inhibitor in the circulation of the same order of magnitude. The two different pools of plasminogen activator inhibitor might have a different physiologic function.
The von Willebrand Factor in Myocardial Infarction and Unstable Angina: A Kinetic Study
Authors: Margulis Tamara , David Miriam , Maor N , Soff G A , Grenadier E , Palant A , Aghai Esther 
Published: July 2018

SummaryRecent studies have demonstrated elevations of von Willebrand Factor following acute myocardial infarction (AMI). In order to determine if this parameter may serve as a marker for AMI, we tested the blood levels of vWF and Factor VIII :C in 28 patients with AMI, 9 patients with unstable angina, 7 patients with atypical chest pain, and 25 healthy volunteers. The level of ristocetin cofactor activity of vWF was between 70 and 144% in the control group. In patients with AMI, the mean level of this activity was 175% on the first day following infarction, rose to a peak of 270% on the fifth and sixth days, and was still significantly greater than normal in all patients on the 14th day. The vWF: Ag level closely paralleled the rise of ristocetin cofactor activity of vWF, with a peak of 336% on day 5. FVIII :C was not significantly changed. No significant elevation of vWF was observed in patients with unstable angina. The ristocetin cofactor activity of vWF and vWF: Ag thus are sensitive biochemical indicators for recent AMI, and may serve as useful markers for up to 14 days following infarction, when the traditional enzymes have returned to normal levels.
α2-Antiplasmin: Functional Characterization and Metabolism in a Heterozygote Deficient Patient
Authors: Knot E A R , ten Cate J W , Lamping R J , Kian Gie Liem 
Published: July 2018

SummaryAn 81-year-old male with a mild life-long bleeding history and an α2-antiplasmin (α2-AP) plasma level of 55% biological activity and 41% antigen activity (normal range 80-140%) was studied. The ratio of plasminogen binding (PB): non-plasminogen binding (NPB) α2-AP assayed by modified crossed immunoelectrophoresis (CIE) was 7.3/2.7 (controls 6.3 ± 0.49 SD/3.7 ± 0.49 SD). The patient’s α2-AP showed decreased affinity for fibrin, i. e. 8.3% versus 32.4% of normal control α2-AP associated with fibrin during clotting of plasma. A metabolic study performed with human purified 125I-α2-AP(PB/NPB 7.7/2.3) showed a plasma radioactivity disappearance half-life of 72.9 h (n 60.1 ± 5.3 h) with a normal fractional catabolic rate and a reduced absolute catabolic (synthetic) rate of 0.70 mg/kg/day (n 2.10 ± 0.60 mg/kg/day). The exchange between the central and third compartment was increased. The increased α2-AP PB form and the increased plasma radioactivity disappearance half-life are suggestive of a slower conversion of the PB form into the NPB form and/or slower degradation of the PB form. The bleeding tendency in this patient could be explained by decreased synthesis of α2-AP and decreased binding to fibrin.
Calibration of BCT/441, the ICSH Reference Preparation for Thromboplastin
Authors: Thomson Jean M , Darby K V , Poller L 
Published: July 2018

SummaryAn international collaborative exercise has been undertaken to calibrate a secondary international reference preparation (IRP) of thromboplastin on behalf of the International Committee for Standardization in Haematology (ICSH). This preparation of British Comparative Thromboplastin (BCT/441) is required because supplies of the WHO primary IRP (BCT/253) are necessarily limited.The calibration was performed at seven centres with only a small degree of interlaboratory variation. As a result of this study an ISI value of 1.04 has been assigned to the preparation.Opportunity was also taken to assess the reliability of a simplified calibration based on lyophilised plasmas. The results of the latter appeared reliable.BCT/441 will be available to officially designated National Control Laboratories for calibration of local thromboplastins to promote prothrombin time standardization in oral anticoagulant control.
Monoclonal Antibodies Towards the Fast Inhibitor of Tissue Plasminogen Activator from Human Plasma and Serum
Authors: Urdén G , Johansson Ulla , Chmielewska Joanna , Brandt J , Wiman B 
Published: July 2018

SummaryHybridoma cells were produced by fusing mouse myeloma cells (SP 2/0 - Ag 14) with spleen cells from a Balb/c mouse, previously immunized with the partially purified complex between tissue plasminogen activator (t-PA) and its fast inhibitor from human plasma (serum). Screening with a radioimmunoassay revealed a number of hybridomas secreting antibodies directed towards the complex. Of these, about 1/3 reacted both with the complex and t-PA, whereas about 2/3 reacted only with the complex. Three of the latter hybridomas, producing antibodies directed towards the inhibitor-moiety in the complex have been cloned and the antibodies were studied in detail. PA-inhibitor activity in plasma or serum and t-PA/PA-inhibitor complex could be specifically adsorbed on all three insolubilized monoclonal antibodies (MCI, MC2 and MC3). None of the antibodies seems to be directed against structures of vital importance for the functional activity of the PA-inhibitor. In accordance with this finding the antibody with the highest avidity (MCI) reacts equally well with the PA-inhibitor alone or in complex with t-PA. A radioimmunoassay was devloped with this antibody and significant displacement was obtained with samples with PA-inhibitor concentrations above 2 AU/mL. In 13 plasma samples with different levels of PA-inhibitory activity a significant correlation was obtained when comparing this activity with the PA-inhibitor antigen as measured with the radioimmunoassay (r = 0.88).
Investigation of a Congenital Abnormal Plasminogen, Frankfurt I, and Its Relationship to Thrombosis
Authors: Scharrer I M , Wohl R C , Hach V , Sinio L , Boreisha I , Robbins K C 
Published: July 2018

SummaryA new abnormal plasminogen, Frankfurt I, has been identified in the plasma of a 42 year-old male patient who has recurrent deep vein thrombosis. Clinical laboratory data showed normal hemostasis test results. Since plasma plasmin generation rates gave low values, the fibrinolytic system was analyzed for a possible fibrinolytic system defect. Functional and antigen plasminogen concentrations both in the plasma and with the isolated, purified plasminogen showed that only 49% of the antigen concentration had potential functional active sites. Also, a reduced antigen concentration was found in both the propositus, and his mother (46% active sites).Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the purified Frankfurt I plasminogen showed a normal native Glu-plasminogen band. Crossed-immunoelectrophoresis revealed a peak with normal size and shape, but displaced with respect to normal Glu-plasminogen toward the anode, i. e., was, as a whole, more negatively charged. Isoelectric focusing followed by zymog-raphy on a agarose-fibrin plate proved this observation, but did not indicate a separation of the normal from the abnormal plasminogen molecular species, also, fewer bands were found in the abnormal plasminogen isozyme pattern.Kinetic studies of Frankfurt I Glu-plasminogen and plasmin led to the conclusion that most of the functional abnormality is related to absence of active sites in half of the molecules. The plasmin generated was very unstable in the absence of stabilizing ligands and/or substrates. After reduction, the plasmin was completely converted to the typical two plasmin chains, A and B.
Absence of Transplacental Passage of Pentosan Polysulfate During Mid Trimester of Pregnancy
Authors: Forestier F , Fischer A M , Daffos F , Beguin S , Diner H 
Published: July 2018

SummaryEight women who were going to have an abortion between the 18th and 23rd week of gestation for chromosomal abnormalities or haemoglobinopathies received intravenously 50 mg of pentosan polysulfate (PSP). Maternal results of haemostasis prior and after the injection of the drug were compared. Fetal coagulation parameters were tested on samples obtained by direct puncture of the umbilical cord under ultrasound guidance, 30 min after injection. Results were compared to those of normal fetuses at the same stage of gestation, obtained in the same conditions. In mothers’ plasma, 30 min after injection, APTT was prolonged, factor Xa generation was markedly impaired, and factor V level was deeply decreased. By contrast, no modifications of these parameters were observed in fetal plasma, 30 min after the injection of PSP to their related mothers when compared to control fetuses. Thus the absence of biological modifications induced by PSP injection could demonstrate that this drug does not cross through the placenta.
Hepatitis-Free Interval After Clotting Factor Therapy in First Infused Haemophiliacs
Authors: Morfini M , Rafanelli D , Longo G , Messori A , Rossi Ferrini P 
Published: July 2018

SummaryPost-infusion hepatitis is known to occur very frequently in haemophiliacs after treatment with unheated commercial clotting factor concentrates, obtained from large plasma donation pool. On the contrary, single-donor cryoprecipitate is likely to carry a lower risk of transmitting hepatitis.To evaluate this hypothesis, we retrospectively reviewed the medical records of 25 first infused haemophiliacs (from 1981 to 1984) treated with unheated commercial clotting factor concentrates (n = 19) or cryoprecipitate (n = 6).The hepatitis-free interval after the beginning of therapy was expressed as exposure days. The end point of each patient, i.e. the hepatitis occurrence, was defined as an increase of aminotransferases (ALT and AST) and/or the seroconversion of HBV-markers, which were checked every three months.The life-table method and log-rank test showed that cryo-precipitates had a significantly longer hepatitis-free interval (p = 0.0131, log-rank test) and a lower risk of transmitting hepatitis (p = 0.01-0.05, life-table method) than the commercial concentrates. However, the safety of cryoprecipitate therapy was shown to cover only a few exposure days, and so the real advantage of this product depends on the bleeding frequency of the patient concerned.We believe that these methods and our findings may be useful to assess and compare the safety of the new “heat-treated” clotting factor concentrates.
Bioavailability in Rats of Human Recombinant Tissue Plasminogen Activator After Subcutaneous and Intramuscular Injection
Authors: Garcia Frade L J , Poole S , Hanley S , Creighton L J , Curtis A D , Gaffney P J 
Published: July 2018

SummaryThe bioavailability of human recombinant tissue plasminogen activator (rt-PA) in rats was measured after subcutaneous (s.c.) and intramuscular (i.m.) injection. Rt-PA was absorbed after both i.m. and s.c. injection, giving peak plasma concentrations within 30 min and 1 h, respectively, with detectable concentrations up to 6 h. These peak values of bioavailable t-PA were obtained in a functional fibrin plate assay of euglobulin precipitates and expressed as +88% and +243% (for s.c. and i.m. routes respectively) above basal rat fibrinolytic activity. Prior injection of rt-PA, s.c. or i.m., significantly reduced the weights of thrombi induced in the inferior vena cava after injection.
Quantitative Immunoblotting of Plasma and Platelet Protein S
Authors: Schwarz H Peter , Heeb Mary Jo , Lämmle Bernhard , Berrettini Mauro , Griffin John H 
Published: July 2018

SummaryProtein S, the activated protein C cofactor, was measured in plasma and in platelets by a quantitative immunoblotting assay using a double antibody technique. Either whole plasma or platelet lysates were electrophoresed on sodium dodecyl sulfate polyacrylamide gels and transferred to nitrocellulose membranes by electroblotting. Based on the demonstration of proportional transfer of protein S from the gel to the nitrocellulose membrane, a reproducible and sensitive quantitative assay for protein S antigen (∼ 70,000 MW) was developed that correlated well with the Laurell rocket assay for plasma protein S. Pooled normal plasma contains 22 μg/ml protein S. Total platelet protein S antigen at ∼ 70,000 MW was determined in gel filtered platelets of ten healthy adults (mean, 163 ng per 1088 platelets). In the supernatants of thrombin-stimulated platelets, 63% of the total platelet protein S antigen was measured. Thus, quantitative immunoblotting is a useful method to detect low levels of protein S in platelets or in plasma with the advantage of giving qualitative information, i.e. apparent MW, of protein S.
Factor VIII: C (FVIII: C) Recovery and Half-Life After Infusion of Steam-Treated High Purity Factor VIII Concentrate in Severe Hemophilia A - Comparison of One-Stage Assay, Two-Stage Assay and a Chromogenic Substrate Assay
Authors: Hellstern Peter , Kiehl Ralf , Miyashita Chieko , Schwerdt Holger , von Blohn Gerhard , Köhler Michael , Büttner Maria , Wenzel Ernst 
Published: July 2018

SummaryFactor VIII :C recovery and half-life was measured in 16 hemophilia A patients under comprehensively standardized conditions. Each patient received the same lot of a steam-treated high purity FVIII concentrate at a dose of 19-33 U/kg body weight. A comparison was made between the one-stage assay, the two-stage assay and a chromogenic substrate test for FVIII :C determination using a FXa-sensitive chromogenic substrate. Factor VIII :C potency of the administered FVIII concentrate was measured using calibration curves derived from a concentrate standard and FVIII: C plasma levels were read from calibration curves derived from a plasma standard. The chromogenic assay showed a good reproducibility at FVIII: C levels between 0.015 and 0.50 U/ml. The FVIII :C recoveries calculated from the results of the one-stage assay, the two-stage assay and the chromogenic substrate test were 109 ± 20, 92 ± 14 and 81 ± 11% (x ± SD), respectively. The elimination half-lives of FVIII :C were calculated by non-linear least square analysis using a modified computerized Gauss-Newton algorithm. The half-lives calculated from the FVIII: C plasma levels measured by the one-stage assay, the two-stage assay and the chromogenic test were 23.8 ± 6.4, 22.2 ± 5.7 and 17.1 ± 4.8 h (x ± SD), respectively. No previous study has reported such long half-life values. Our findings indicate that measurements of recoveries and half-lives by the chromogenic FVIII :C assay and by computerized nonlinear least square analysis allow the possibility of individualized FVIII replacement therapy.
Piretanide: A New Synthetic Fibrinolytic and Anti-Platelet Agent
Authors: Chohan I S 
Published: July 2018

SummaryPiretanide, 4-phenoxy-3-(l-pyrrolidinyl)-5-sulfamoyl benzoic acid, a potent diuretic, enhances endogenous plasma fibrinolytic activity after a single dose of 6 mg administered orally. Acceleration of fibrinolytic activity becomes manifest within 1 h, reaches its peak in 3 h and is associated with little change in fibrinogen, however, it is accompanied with diminished urokinase excretion initially. Piretanide does not cause lysis of fibrin in vitro in any concentration. Primary platelet aggregation, induced by adenosine-diphosphate, is inhibited by piretanide, in vivo. In in vitro experiments piretanide leads to effective inhibition of ADP-induced platelet aggregation with complete inhibition at 5 mM concentration. Piretanide, after ingestion of a single dose of 6 mg, causes highly significant decrease of platelet factor-4 release.