bluuebunny/crossref_metadata_2025_split huggingface dataset:
FACTOR XIII CONCENTRATE FOR PROPHYLAXIS OF REBLEEDING IN SUBARACHNOID HEMORRHAGE (SAH) - RESULTS OF A PROSPER TIVE MULTICENTER PILOT STUDY
Authors: Thie A , Henze T h , Deggar D , Obering M , Clemers R , Kleinz H J , Lombard G F 
Published: August 2018

Rebleeding occurs in subarachnoid hemorrhage (SAH) in 20 - 25 % of patients, with a mortality rate being above 50 %. The cause of rebleeding is considered to be premature fibrinolysis of the fibrin clot surrounding the site of rupture. Since the stability of the fibrin clot is influenced by the activity of coagulation factor XIII, and moreover, a factor XIII deficiency has been reported in SAH patients, the question arises as to whether the incidence of rebleeding can be influenced by the administration of F XIII concentrate.During a period of 6 months, 69 patients with acute SAH were enlisted in an open, prospective, multicenter study. On admission, 5 patients were classified as stage I (7.2%) according to the Hunt and Hess scale, 22 as stage III (31.9%), 11 as stage IV (16%) and 9 as stage V (13%). Aneurysm was confirmed by angiography in 52 patients (75%). All the patients received 10 x 1250 U F XIII concentrate during the first 15 days after the initial hemorrhage. Surgery on the aneurysm was performed between day 3 and 32 (median: day 13) in 35 patients.A total of 7 rebleedings occurred in 6 patients (8.7%), of whom 2 were stage I - II and 4 were stage III - V cases. Cerebral infarction was observed in 10 patients (14.5%), and hydrocephalus requiring shunting occurred in 1 patient. There were no cases of peripheral thromboses or embolisms. After 4 weeks, the overall mortality rate was 26%. (stage I - II: 11.1%, stage III - V: 37.5%).The conventional approach in the prophylaxis of rebleeding in SAH is an early operation or intravenous administration of antifibrinolytics. However, as none of these measures significantly reduce overall mortality, the present pilot study investigated a new, therapeutic approach in which F XIII concentrates were administered in order to stabilize the fibrin clots and prevent premature fibrinolysis. The data so far show that Fibrogammin P is an effective and well tolerated agent for the prophylaxis of post-SAH rebleeding. In order to statistically confirm the results of the pilot study, we have, in the meantime, started a prospective, randomized, placebo-controlled, multicenter double-blind study, which will involve 750 patients over a period of 2 years.
MODIFICATION OF FIBRIN POLYMERIZATION INDUCED BY MONOCLONAL ANTIBODIES AGAINST FRAGMENT D DOMAIN OF FIBRIN/OGEN DEGRADATION PRODUCTS
Authors: Mirshahi M , Soria J , Soria C , Mirshaho S , Perrot J Y , Boucheix C , Bernadou A 
Published: August 2018

Monoclonal antibodies (McAb) are often used to detect the domains of a molecule involved in an important function of a biological system.In this work, the effect of 20 McAb directed against the D domain of fibrin/ogen degradation products (FbDP) were analyzed on fibrin polymerization. Two McAb which react with fragment D1 but not with fragment D3 inhibited both thrombin and reptilase-induced fibrin formation. It is therefore suggested that these 2 McAb recognize an epitope in the vicinity of the polymerization site "a" located in the JT 374-396 domain in fibrin/ogen molecule. (This sequence is only present in D1 and not in D3.An inhibitory effect on thrombin and reptilase-induced fibrin formation was also induced by 2 other anti D McAb which recognize an epitope present in both D1 and D3 fibrinogen-degradation products. Therefore, these 2 McAb do not react directly with the polymerizing site "a". A possible mechanism of this inhibition could be a conformational change induced by the binding of these McAb, leading to the masking of the polymerizing site "a". Another possible mechanism of the inhibitory effect is that thrombin and reptilase-induced fibrin formation may involve other sites on the fibrinogen molecule. It should therefore be suggested that unknown domains could be important for fibrin polymerization. These domains may act either directly or indirectly by inducing a three dimensional structure of the native molecule required for the expression of polymerizing domains.
IMMUNO-VISUALIZATION OF FIBRINOGEN AND FIBRIN IN GELS PRDUCED BY GELATION OF PLASMA WITH ETHANOL
Authors: Grøn B , Brosstad F 
Published: August 2018

The Ethanol Gelation Test(=EGT) is a well-documented simple,specific and frequently used test to detect plasma soluble fibrin(Godal & Abildgaard:Gelation of soluble fibrin in plasma by ethanol.Scand.J.Haanat.3,342,1966) .If soluble fibrin present in plasma amounts to 1% or more of the plasma-f ibrinogen conc.,the admixing of 0.15 ml 50% ethanol to 0.5 ml plasma in a test tube will-(subsequent to incubation for 10 min at 20°C)-upon tilting the test tube semi-horizontally produce a characteristic,(upwardly) convex gel. Although earlier studies have confirmed the validity and specificity of EGT as a means to detect soluble fibrin,we found it of interest to see to which degree such soluble fibrin is FXIII-stabilized EGT-positive(from patients with Disseminated Intravascular Coagula-tion(DIC) and EGT-negative plasma was studied as follows: The EGT test was performed as above,and the entire content of the test tube emptied upon a nylon micro-meshed membrane.Applying slight suction underneath the nylon manbrane the fluid was removed,leaving the ethanol precipitated material which was immediately dissolved in SDS (1%)-urea(5M)-Tris-HCl (0.15M,pH8.6). After incubation at 100°C for 1 min the material was SDS-electrophoresed on flat-bed agarose(2%) Subsequent to Western-blotting onto nitrocellulose and gelatine-blocking, the fibrin(ogen)-related pattern was reacted with either: a)polyclonal antibodies to fibrinogen,b)plyclonal antibodies to FPA or c)monoclonal antibody to FPA(gift from Dr.Nieuwenhuizen, Leyden, Holland) .Then,the fibrin(ogen)related pattern was developed using peroxidase-conjugated secondary antibodies.From the specificity of the primary antibodies used,it could be deduced that:1)A substantial amount of the soluble fibrin content of DIC-plasma was present in an oligomeric form(up to 6-mers) .2)These oligomers contained fibrinogen, i.e. thus representing FXIII-1 inked fibrinogen/fibrin hybride molecules .3) Even normal plasma contained some detectable oli-gomers(up to 3-mers) .4) Col lecting blood with all appropriate thrombin- and FXIII-inhibitors did not change the patterns obtained and described above.It may be concluded that soluble fibrin occurs mainly in a FXIII-stabilized,oligomeric form which contains fibrinogen Due to the nature of the polymerization process,the fibrinogen moiety of these hybride molecules must be end-located representing a physiological means to inhibit further polymer growth.
HUMAN PLASMA FIBRINOGEN MOLECULAR WEIGHT VARIANTS:CHARACTERIZATION BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND IDENTIFICATION BY SEQUENCE ANALYSIS
Authors: Müller E , Henschen A 
Published: August 2018

Human plasma has been shown to contain several fibrinogen variants which differ from each other in molecular weight. The three most common forms, with molecular weights of 340 kD, 305 kD and 270 kD, have been reported to change considerably in their relative amounts during certain pathophysiological processes such as acute phase reactions, disseminated intravascular coagulation, fibrinolytic disorders, liver disease and cancer. Though it has been suggested that the differences in molecular weight are due to degradation of one or both, respectively, of the carboxy-terminal parts of the Aα-chains, the removed or altered segments have so far never been precisely determined. Consequently, it has only been possible to speculate about the origin of the variants.The aim of this study was to isolate the various molecular weight variants from plasma and to characterize their peptide chain components proteinchemically. Fibrinogen was first isolated from plasma by glycin precipitation and the variants were then separated by stepwise ammonium sulfate precipitation, taking advantage of their different solubility.The peptide chain components of the various fractions were isolated by reversed-phase high-performance liquid chromatography (HPLC). The N-termini were identified by direct sequence analysis. Chemical and enzymatic cleavages of the peptide chains resulted in fragment mixtures which were compared with the corresponding mixtures obtained from commercial fibrinogen by HPLC fingerprinting. Finally, the fragments which differed were identified by N-terminal sequence and amino acid analysis so that the exact C-termini of the peptide chains,especially in the lower molecular weight variants,could be determined. With the help of this information conclusions may also be drawn about the origin of the lower molecular weight variants and about the mechanism by which they may he formed.
STRUCTURE AND FUNCTIONAL PROPERTIES OF A FIBRINOGEN EERIVATIVE FORMED BY LIMITED PROTEOLYSIS WITH RED BLOOD CELL
Authors: Lipinski B , Ewaskiewicz J , Niewiarowski S , Budzynski A Z 
Published: August 2018

Normal human plasma contains, in addition to fibrinogen (Mr 340,000), two major thranbin-coagulable fibrinogen derivative of Mr 320,000 and 300,000. Previous investigations demonstrated that these derivatives do not originate from plasmic cleavages, however, no enzyme(s) responsible for the cleavages have been identified. The purpose of this study was to investigate a possible role of red blood cells (RBC) in the formation of these physiologic fibrinogen derivatives. RBC ghosts were prepared from ACD blood obtained from normal donors after removal of leukocytes and platelets. Purified human fibrinogen, that contained only one band of Mr 340,000 as judged by SD6-PAGE, was incubated with RBC ghosts at 37°C. SDS-PAGE of the supemate revealed the presence of a single band of approximate Mr 275,000 after one hour of incubation. Proteolytic degradation of fibrinogen by RBC ghosts was inhibited by STI but not by trasylol, leupeptin or EDTA suggesting that putative enzyme is distinct frcm plasmin and calpain. Polypetide chain ánalysis of Mr 275,000 derivative demonstrated degradation of its A alpha chain. The derivative shewed an impaired binding to AEP-activated platelets as shown by decreased number of fibrinogen binding sites calculated frcm Scatchard plots.Study of polymerization reaction of Mr 275,000 derivative catalyzed by thrombin revealed significantly impaired kinetics.The maximum polymerization rate of Mr 275,000 monomers was 51% of that of intact fibrinogen. The data suggest that RBC ghosts contain enzyme (s) that are capable to induce a limited proteolytic degradation of fibrinogen that may contribute to alteration of its biologic functions inportant in hemostasis and thrombosis.
CALCIUM-INDUCED FORMATION OF FIBRINOGEN -- FIBRIN COMPLEXES
Authors: Kaminski M , McDonagh J 
Published: August 2018

Presence of calcium chloride (8.3 mM) at u = 0.1 enhanced precipitate formation in several different fibrinogen preparations. The precipitate had gel like properties and demonstrated syneresls when disturbed. Precipitation proceeded in the time dependent manner with a plateau after 30 min. The amount of precipitate ranged from 4-24% of total protein content of different preparations. Precipitates did form at u = 0.1 without calcium ion; however, the amount of protein was 3 to 7 fold less than when calcium ion was present.SOS gel electrophoresis of calcium precipitates demonstrated cross-linking of gamma chains. Cross-linking, but not precipitate formation was blocked by parachloromercurie-benzoate (PCMB). The precipitates were redissolved in 2M urea, treated with thrombin, and analyzed for flbrinopeptide content by HLPC. Precipitate formed in absence of calcium ion contained 19% of FPA and 89% of FPB. Precipitates formed in the presence of calcium ion contained 49% of the expected amount of FPA and 98% of expected FPB. The precipitation phenomenon could be reproduced after fibrin monomer-free fibrinogen (prepared by dialysis of calcium supernatants against calcium free buffer) was treated briefly with thrombin.The above finding suggests that calcium ion enhances polymerization of Intact fibrinogen and molecules missing one or two FPA's.
ROLE OF ANTITHROMBIN FOR INACTIVATION OF THROMBIN ON ENDOTHELIUM
Authors: Swedenborg J , Frebelius S , Nydahl S , Olsson P 
Published: August 2018

Inactivation of thrombin which occurs mainly on the endothelium requires binding of the enzyme to receptors on the endothelial cells. One receptor for thrombin is glycosaminoglycans (GAG). Antithrombin (AT), however, also binds to GAG and may be involved in endothelial inactivation of thrombin.The purpose of the present study was to study the role of AT for the inhibition of thrombin on endothelium. The experiments were performed on rabbit aorta segment in vitro. Thrombin in solution and on the endothelial surface was functionally assayed with aid of a synthetic chromogenic substrate (thrombinS) or fibrinogen (thrombinF). In the latter case liberation of fibrinopeptide A (FPA) was measured. Inactivation of thrombin was estimated by the difference between loss of thrombin from the solution and recovery of thrombin on the endothelial surface during the incubation with thrombin.Preincubation of the endothelium with AT or plasma increased the inactivation of both thrombinS and thrombinF but AT-free plasma had no such effect. Preincubation with heparin (5 IU ml) decreas-the inactivation of thrombin on the endothelium. Endothelial segments preincubated with AT caused a much more rapid inactivation of thrombin over time as compared to control segments. Aortic segments preincubated with heparin caused a slower inactivation of thrombin on the sruface as compared to control segments.It is concluded, that preincubation with AT enhances the inactivation of thrombin on the endothelium whereas preincubation with heparin has the opposite effect. Heparin causes liberation of endogenous AT from the endothelial surface which may explain the decreased inactivation on the surface in the latter case.
VASCULAR DAMAGE IN PATIENTS ON CHRONIC HEMODIALYSIS
Authors: Izumi K , Noguchi M , Iwasaki E , Deguchi K , Shirakawa S 
Published: August 2018

Calcification in the abdominal artery and endothelial cell function of the peripheral veins were studied in the patients recieving maintenance hemodialysis for the chronic renal failure.The grade of calcification was expressed by the aortic calcification index (ACI) calculation from the abdominal CT scan films. The endothelial cell function was estimated from the release capasity for tissue plasminogen activator (t-PA) and von Willebrand factor (vWF), and the fibrinolytic capacity (by ELT and fibrin plate lysis area) during 10-min venous occlusion (VO) of the cubital vein. The dialysed patients were divided into 4 groups according to the duration of hemodialysis : group A ; under 1 year (n=7), group B ; 1-4 years (n=14), group C ; 4-7 years (n=15) and group D ; 7-10 years (n=8).The level (X + SD) of vWF : Ag, vWF act. (RCoF) and t-PA in patients before VO were 439 ± 255(%),171 ± 42(%), 4.2 ± 0.6(ng/ml) in group A, 292 ± 157, 151 ± 35, 4.1 ± 1.2 in group B, 174 ± 114, 133 ± 47, 3.7 ± 0.8 in group C and 130 + 27, 66 ± 21, 3.1 ± 0.7 in group D, respectively. With the increase in the duration of hemodialysis, the release capacity for vWF and t-PA, and the fibrinolytic capacity during VO decreased regardless of the aggravation of fibrinolytic activity before VO, When the activity was estimated by ELT, Cl-inactivator resistant fibrinolytic activity and fibrin lysis area. These findings are thought to reflect the exhaustion of endotherial cells. In elder patients (60-80 years old), the release capacity for vWF and t-PA during VO decreased with the increase in the ACI level.It is conclude that the patients on chronic hemodialysis have a greater incidence of calcification of abdominal artery and lower function of endothelial cells in the cubital vein than non-dialysed control.
PERMSELECTIVITY OF CULTURED ENDOTHELIAL MONOLAYERS: EFFECT OF SIZE AND CHARGE OF THE TRANSPORTED MOLECULES
Authors: Bizios R , Blumenstock F A , Del Vecchio P J , Malik A B 
Published: August 2018

Known molecular size neutral dextrans (molecular weight (MW) range ∼6,000-∼500,000), anionic (dextran sulfate, ∼500,000 MW), and cationic (DEAE-dextran, ∼500,000 MW) were used to determine the permselectivity characteristics of bovine pulmonary arterial endothelial monolayers. The experimental system consisted of two compartments separated by a gelatinized polycarbonate membrane (0.8 μm pore size) on one side of which endothelial monolayers were grown to confluence. Dextran solutions (1 gram %) were prepared in phosphate buffered saline buffer (containing 0.5 gram % serum albumin) and placed on the luminal side. Transendothelial dextran transport at 37°C was studied as a function of time. Dextran concentrations were determined spectrophotometrically using the anthrone method. The results (mean ± S.E.) of the dextran concentrations in the abluminal compartment at 45 minutes are given in the table.The endothelial monolayers markedly restricted dextran transport compared to transport across gelatinized, polycarbonate membranes alone (controls). Furthermore, the results indicate that size and charge of the transported molecules determine the sieving mechanism responsible for their passage across the cultured endothelial monolayer. (Supported by HL32418.)
FACTOR VIII IN VIRUS INFECTED CELLS: A LIGHT MICROSCOPIC OBSERVATION
Authors: Bruggeman C A , Debie W H M , van Dam-Mieras M C E 
Published: August 2018

Viruses may be important in atherosclerosis as inciters of arterial injury or as modulators of the metabolism of the infected cells. Cytomegalovirus (CMV) is one of the members of the herpesvirus family ;that infect human beings. Virus was detected in arterial walls of patients with atherosclerosis (1). The effect of CMV on endothelial cells and on the metabolism of these cells was subject of this study.Human endothelial cells monolayers were established from cells obtained by collagenase treatment of human umbilical cord veins and arteries. The cells were grown in medium 199 containing growth factor and 20% fetal calf serum. All monolayers were near confluency at the time of viral infection. The cells were purified by FACS cell sorting using dilacLDL as marker (2). Infection of endothelial cells was performed using CMV laboratory strains ADI69 and Kerr and wild strains isolated from immunosuppressed patients (obtained by Dr. H.T. Wei land, Dept. Virology, University of Leiden, The Netherlands). Intracytoplasmic and intra-nuclear viral antigens were detected in 10-20% of the endothelial cells by fluorescence microscppy using TRITC-labeled monoclonal antibodies against CMV. Centrifugation of the cell monolayer during virus incubation resulted in an increase in the percentage of virus positive cells. The effect of virus infection on presence ot Tacxor VIII in the cells was studied using fluorescence microscopic examination of cell monolayers using a double staining technique. The presence of factor VIII in the cytoplasm of the cells was demonstrated using FITC-labeled antibodies and viral antigens were demonstrated by TRITC-labeled antibodies The results of these experiments showed that HCMV-infection of endothelial cells resulted in the disappearance of factor VIII from the cytoplasm of the endothelial cells at 48-72 hrs post infection without affecting the viability of the infected cells. The importance of this finding in relation to the function of the endothelial cells will be discussed.References:(1) Melnick, J.L. et al. The Lancet (1983): 644-647.(2) Voyta, J.C. et al. J. Cell Biol. 99 (1984): 2034-2040.
PURIFICATION AND PARTIAL CHARACTERIZATION OF A BIOACTIVE SUBSTANCE FROM RAT'S VESSEL WALL INDEPENDENT OF PROSTACYCLIN PRODUCTION
Authors: Kempfer A C , Maugeri N , Farías C , Bermejo E , Gimeno M , Lazzari M 
Published: August 2018

Our previous observations provided evidence that a bioactive substance (BAS) with inhibitory effect on platelet aggregation and with inotropic activity on smooth muscle preparations is present in aortic wall of rats treated previously with indomethacin. The ability to inhibit platelet aggregation was used for monitoring its purification and partial characterization. The original sample was extracted by rinsing aortic rings (1.5 mg dried rings) in buffer Krebs (300 μl) for 40 minutes at room temperature. The substance was purified by gel filtration (Bio-gel P-30, Sephadex G-100, Sephadex G-75) and ion exchange chromagra-phy (DEAE cellulose). In the last method, salt gradient elution was performed. Further purification by Sephadex G-50 resulted in removal of 90% of the contaminating substances without a loss of inhibitory activity. The main peak of both chromatographic procedures was analyzed on SDS-PAGE and PAGE with denaturing solvents. The substance was evident by Coomassie Brilliant Blue and periodic acid Schiff staining.In order to determine if the BAS was susceptible to proteolysis, an aliquot of the original sample (29 ug total protein) was incubated with trypsin (final concentration 0.3 μg/ml) and with chymotrypsin (final concentration 3 μg/ml). The BAS activity was not detected. An aliquot of the same original sample was incubated with neuraminidase (final concentration 1.2 units). The BAS activity was detected.The substance appeared to be stable for at least 18 hours at room temperature and 2 hours at 37°C, In addition it was stable over a pH range between 6.8 to 8.6, showing an anionic behaviour.The protein concentration of this substance determined by the method of Lowry was 1 μg/mlPartial characterization supports the conclusion that the substance present in aortic wall of rats is a homogeneous protein, which has a molecular size estimated at 55-65 kDa.
INHIBITORY EFFECTS OF ITP SERA ON BINDING OF ANTIPLATELET GLYCOPROTEIN (GP) IIb/IIIa MONOCLONAL ANTIBODIES TO HUMAN UMBILICAL VASCULAR ENDOTHELIAL CELLS (HUVE)
Authors: Nakajima T , Koyama T , Nishida Y , Tanaka H , Kakishita E , Nagai K 
Published: August 2018

Some ITP patients have specific autoantibodies to platelet GP IIb/IIIa. On the other hand, HUVE were shown to synthesize platelet GP IIb/IIIa like substances. Therefore, we studied the binding of ITP sera to HUVE by showing the inhibitory effect of ITP sera on the binding of anti-platelet GP IIb/IIIa monoclonal antibodies to HUVE. HUVE were cultured according to the method of Jaffe et al. 125-I-anti-platelet GP IIb/IIIa monoclonal antibody (125-I-Anti-GP) (40.3 mCi/mg), 40 yl, was added to a cell suspension of HUVE (1.5 × 104/500 μl) in a plastic RIA tube. After incubation for 30 min. at 4°C and centrifugation of 10,000 xg for 3 min., the radioactivity of the cell pellet was measured. Specific binding was determined by determining the difference between cell-bound radioactivity in the absence and presence of an excess amount of unlabelled ligand at 100 x concentrations. Scatchard analysis using 125-I-Anti-GP showed that the maximum binding capacity was 8 × 104/cell and Kd was 40.2 nM. The binding rate of 125-I-Anti-GP to HUVE treated with ITP (high PAIgG) sera (n=6) was 15.2±3.3% compared with 24.0±7.5%, observed for HUVE treated with normal sera (n=10). Treatment of ITP sera to HUVE significantly lowered the binding of 125-I-Anti-GP to HUVE (P<0.05). A combined analysis of SDS-PAGE and Western blotting of washed platelet and endothelial cell lysates shows that two proteins from each cells had similar or identical molecular masses to GP IIb/IIIa.These findings show that there are GP IIb/IIIa on the HUVE, ITP sera from our patients may have antibodies to HUVE GP IIb/IIIa and that anti-platelet GP IIb/IIIa antibodies in the ITP sera may bound not only to some platelets, but also to the HUVE