bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagnostic Efficacy of Plasma Urokinase-type Plasminogen Activator and Plasminogen Activator Inhibitor-2 in Differentiation of Hepatocellular Carcinoma from Cirrhosis
Authors: Song Kyung Soon , Lee Anna , Choi Jong Rak , Kwon Oh Hun 
Published: July 2018

SummaryWe determined the plasma antigen levels of urokinase-type plasminogen activator(u-PA) and plasminogen activator inhibitor 2(PAI-2) in 41 patients with hepatocellular carcinoma and 28 patients with different stages of liver cirrhosis. No significant differences of u-PA and PAI-2 levels were calculated between the two groups of tumor patients (HCC) and liver cirrhosis without tumor (non-HCC).Within both study groups, no significant differences were found in u-PA and PAI-2 levels of the different Child categories. Discriminative functions of both u-PA and PAI-2 (total error count estimates of 43.1% and 43.6%, respectively), were low compared to that (29.0%) of alpha-fetoprotein (AFP). The combinations of AFP and u-PA lowered the total error rate (21.9%) more than that of each marker alone. However, whether plasma u-PA and PAI-2 may be considered as a risk factor further investigation was needed and our findings raise the question as to whether these markers could be considered as useful screening markers for earlier detection of HCC in liver cirrhosis because discriminant functions of u-PA and PAI-2 were not significant.Sensitivities and specificities of u-PA and PAI-2 were also not high enough, resulting in the ranges of total diagnostic efficiency from 43% to 50%, and, from 49% to 63% , respectively, at different cut-off values. No direct relationship was detected between AFP and u-PA, between AFP and PAI-2, and between u-PA and PAI-2.
“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate
Authors: Arrighi Silvana , Rossi Roberta , Borri Maria Giuseppina , Lesnikov Vladimir , Lesnikov Marina , Franco Elena , Divizia Maurizio , Santis Maria Elena De , Bucci Enzo 
Published: July 2018

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.
Residence Time in Niches of Stagnant Flow Determines Fibrin Clot Formation in an Arterial Branching Model - Detailed Flow Analysis and Experimental Results
Authors: Reininger Armin J , Reininger Cornelia B , Heinzmann Ulrich , Wurzinger Laurenz J 
Published: July 2018

SummaryDeposition of blood components in branching flow has been investigated primarily with regard to platelets. We instead examined thrombin-induced fibrin clot formation in separated laminar as well as turbulent branching flow. The most rapid clot growth and largest clot mass was obtained at the lowest inflow rate. Increased inflow reduced the clot size and turbulence completely prevented clot formation. Examination of corresponding flow conditions revealed the recirculation zone in laminar flow to be characterized by two stationary, counterrotating vortices. Niches of stagnant flow, exhibiting long residence times, low wall shear rates and characterized by convergent flow, were spared between the bulk flow and these vortices. Here, fibrin clot growth continued even when shear rates were increased more than 100-fold. Our results indicate that, in branching flow, the long residence times and convergent flow characteristic of flow niches rather than shear rate are critical for fibrin clot formation.
Changes in Haemostatic Variables Induced by Oral Contraceptives Containing 50 μg or 30 μg Oestrogen: Absence of Dose-dependent Effect on PAI-1 Activity
Authors: Scarabin Pierre-Yves , Plu-Bureau Geneviéve , Zitoun Daniéle , Bara Lucienne , Guize Louis , Samama Michel Meyer 
Published: July 2018

SummarySeveral studies have suggested a dose-response relation between the oestrogen content of oral contraceptive (OC) and the risk of both venous thrombosis and arterial disease, when oestrogen doses were higher than 50 μg. However, there is no clear epidemiological evidence for a decrease in thrombotic risk with formulations containing less than 50μg oestrogen. Therefore, we investigated haemostatic variables in users of OC containing either 30 μg (35 women) or 50μg (29 women) ethinyl estradiol as compared with non users (64 women) matched for age and smoking status. Mean values of antithrombin activity were significantly lower in 30 γg or 50 μg oestrogen users than in non users (96% and 98% vs 105%, respectively, p<0.001), but they were not significantly different between the two groups of OC users. There was a significant increase in mean values of factor VII antigen in women taking either 30μg or 50μg oestrogen as compared with non users (96% and 101% vs 85%, respectively, p<0.005). Although the difference between both groups of OC users was not significant, a positive linear trend in factor VII levels was observed within the 0-50μg oestrogen range (p <0.001). Mean levels of fibrinogen were slightly higher in 30μg or 50μg oestrogen users than in non users (2.71, 2.66 g/l vs 2.55 g/l, respectively,), but there was no significant difference between the three groups. Mean values of PAI-1 activity were significantly lower in both groups of OC users than in non users (4.89 and 4.63 AU/ml vs 6.47 AU/ml, respectively, p <0.02), but this decrease was not dose-dependent. There was no significant difference in haemostatic variables between 30 μg oestrogen preparations containing either 100μg (13 women), 150μg (3 women) or 200μg (19 women) levonorgestrel. In 50μg oestrogen preparations, the wide range of different types of progestogens did not allow valid assessment of proge- stogens effect. These data provide further evidence for an alteration of blood coagulation and fibrinolysis in OC users within the 30μg-50μg oestrogen range. However, despite a possible dose-dependent effect of oestrogen on factor VII, our results suggest no substantial change in PAI-1 activity and other markers of thrombogenic risk when oestrogen content of combined OC is decreased from 50μg to 30μg. The potential role of progestogens in haemostatic system needs further investigations.
Aurintricarboxylic Acid Reduces Platelet Deposition in Stenosed and Endothelially Injured Rabbit Carotid Arteries more Effectively than other Antiplatelet Interventions
Authors: Golino Palolo , Ragni Massimo , Cirillo Plinio , Pascucci Immacolata , Ezekowitz Michael D , Pawashe Aruna , Scognamiglio Annalisa , Pace Leonardo , Guarino Angela , Chiariello Massimo 
Published: July 2018

SummaryIn the present study we tested the effects of different antithrombotic interventions on platelet deposition in experimentally-stenotic rabbit carotid arteries with endothelial injury. Platelet deposition, quantitated by labeling autologous platelets with 111 In-oxine, was significantly reduced compared to control animals by all interventions tested, i.e., R 68070, a drug with thromboxane A2 synthase and receptor blocking properties, BN 52021, a PAF receptor antagonist, aurintricarboxylic acid (ATA), an inhibitor of platelet glycoprotein (Gp) Ib/von Wille-brand factor (vWf) interaction, AZ-1, a monoclonal antibody against rabbit GPIIb/IIIa, the platelet receptor for fibrinogen, and AP-1, a monoclonal antibody against rabbit tissue factor. ATA was significantly more effective than all the other interventions in reducing platelet deposition in the stenotic vessels. We conclude that inhibition of Gp Ib/vWf interaction may be a more suitable target for antithrombotic therapy under conditions of high shear stress, like those produced in this model.
Induction of Immune Tolerance in a 7-Year-Old Hemophiliac with an Anaphylactoid Inhibitor
Authors: Harper James L , Gill Joan C , Hopp Russell J , Evans John , Haire William D 
Published: July 2018

Summary
Background: Anaphylactic reactions were a rare complication of low purity VIII concentrates, hut not with high purity VIII concentrates
Case: 7 y/o WM with severe hemophilia A, received only cryoprecipitate and monoclonally purified VIII concentrates; developed post-infusional urticaria. A 2-Bethesda-unit inhibitor was detected. Generalized urticaria and bronchospasm following factor developed as the titer increased. Skin tests demonstrated reactivity to plasma derived VIII, but not recombinant VIII (rhVIII). Attempts at desensitization using rhVIII failed. KLISA revealed an anti-VIIl IgB antibody. He was treated with a modified tolerance regimen using rhVIII starting at 500 U/day with aggressive premedication. The dosage increased by 200 U weekly as tolerated to a maximum of l00U/kg/d without symptoms. Results: His antibody titer decreased rapidly once he started l00U/kg/d. Six months later, the inhibitor was <1 Bethesda unit. Conclusion: Immune tolerance induction using a graduated dosage of rhVIII was successful.
Characterization of a cDNA for Rhesus Monkey Protein C Inhibitor – Evidence for N-Terminal Involvement in Heparin Stimulation
Authors: Radtke Klaus-P , Fernández José A , Villoutreix Bruno O , Greengard Judith S , Griffin John H 
Published: July 2018

SummarycDNAs for protein C inhibitor (PCI) were cloned from human and rhesus monkey
1
liver RNAs by reverse transcription and polymerase chain reaction (PCR) amplification. Sequencing showed that rhesus monkey and human PCI cDNAs were 93% identical. Predicted amino acid sequences differed at 26 of 387 residues. Pour of these differences (T352M, N359S, R362K, L3631) were in the reactive center loop that is important for inhibitory specificity, and two were in the N-terminal helix (M8T, E13K) that is implicated in glycosaminoglycan binding. PCI in human or rhesus monkey plasma showed comparable inhibitory activity towards human activated protein C in the presence of 10 U/ml heparin. However, maximal acceleration of the inhibition of activated protein C required 5-fold lower heparin concentration for rhesus monkey than for human plasma, consistent with the interpretation that the additional positive charge (E13K) in a putative-heparin binding region increased the affinity for heparin.
Conformational Changes in Low Molecular Weight Kininogen Alters Its Ability to Bind to Endothelial Cells
Authors: Hasan Ahmed A K , Zhang Jie , Samuel Mathew , Schmaier Alvin H 
Published: July 2018

SummaryThe plasma kininogens, high (HK) and low (LK) molecular weight kininogens, are the parent proteins for bradykinin, a potent vasoactive peptide that locally influences vascular biology. Binding of both HK and LK to the endovascular wall contributes to bradykinin delivery. Recently, we found one preparation of LK (LKd) which had reduced inhibition of biotin-HK binding to endothelium. The functional defect in LKd was not merely due to bradykinin loss because two preparations of bradykinin-free LK blocked biotin-HK binding. However, using two different particular monoclonal antibodies to bradykinin, LKd, but no other preparation of LK, had its epitope to bradykinin exposed on nonreduced samples on immunoblot. These data suggested that LKd had an altered conformation which exposed the amino terminal arginine of bradykinin to antigenic detection. The altered conformation of LKd allowed it to be more susceptible to trypsin proteolysis. On circular dichroism, the percentage of α-helix was significantly increased, indicating an alteration in the protein. This alteration in LKd was not due to a loss of molecular mass of the protein. On laser desorption mass spectroscopy, the molecular mass of LKd was similar to the other preparations of LK. Investigations were performed to ascertain the mechanism by which LKd had altered ability to bind to cells. LKd was found to be proteolyzed by an unknown protease at the beginning of domain 2 between threonine119and alanine120. Reduction of functional LK with dithiothreitol to expose its bradykinin epitope did not produce the LKd defect. Proteolysis of functional LK with plasma kallikrein, elastase followed by plasma kallikrein, chymotrypsin, or bromelain also did not produce the defect seen in LKd. These combined data indicated that LK maintains a particular conformation that allows the protein to orient itself such that it can bind to endothelial cells. Proteolysis in the surface exposed region between domains 1 and 2 probably allows for the protein to unfold and contributes to its lost ability to bind to endothelial cells.
Orientation of the Carboxy-terminal Regions of Fibrin γ Chain Dimers Determined from the Crosslinked Products Formed in Mixtures of Fibrin, Fragment D, and Factor XIIIa
Authors: Siebenlist Kevin R , Meh David A , Wall Joseph S , Hainfeld James F , Mosesson Michael W 
Published: July 2018

SummaryThere are two schools of thought regarding the orientation of the intermolecular ∈-amino-(γ-glutamyl) lysine isopeptide bonds formed between γ chains in the D domains of assembled fibrin fibers. Some investigators believe that these bonds are oriented parallel to the direction of fiber growth (longitudinally) at the contacting ends of fibrin D domains (‘DD-long’), whereas others believe that these bonds are oriented across the two-stranded fibril, between D domains in opposing strands (‘DD-transverse’). To distinguish between these two possibilities, the structure of crosslinked products formed in mixtures of fibrin, plasmic fragment D, and factor XIIIa were analyzed, based upon this rationale: Complex formation between D fragments and a fibrin template depends upon the non-covalent ‘D:E’ interaction between each fibrin E domain and two D fragments (‘D:fibrin:D’). If carboxy-terminal γ chains in the D:fibrin:D complex become aligned in a DD-long configuration, only crosslinked fragment D dimers (‘D-D’) will result and the fibrin ‘template’ will not become crosslinked to the associated D fragments. If instead, γ chain crosslinks form transversely between the D fragments and fibrin, covalently linked D-fibrin complexes will result.SDS-PAGE of factor XIIIa crosslinked mixtures of fibrin and fragment D demonstrated products of a size and subunit composition indicating D-fibrin and D-fibrin-D formation. Small amounts of D dimers were also formed at the same levels as were formed in mixtures of fragment D and factor XIIIa alone. Electron microscopic images of D-fibrin-D complexes prepared under physiological buffer conditions demonstrated that the D fragments were associated with the central E domain of the fibrin molecule, but that they could be dissociated from this non-covalent association in 2% acetic acid. These findings indicate that γ chain crosslinks occur transversely in D:fibrin:D complexes and permit the extrapolated conclusion that γ chain crosslinks are also positioned transversely in an assembled fibrin polymer.
Magnesium Modifies the Responses of Platelets to Inhibitory Agents which Act Via cAMP
Authors: Hardy E , Glenn J , Heptinstall S , Rubin P C , Horn E H 
Published: July 2018

SummaryThis study has investigated the interaction of raised extracellular magnesium and agents which act via cAMP with respect to inhibition of platelet aggregation and effects on platelet cAMP accumulation.Iloprost (3 ng/ml) and PGD2 (0.2 μg/ml) each caused time dependent increases in platelet cAMP which were significantly greater in the presence of 3 mM added MgS04 (p <0.01). Addition of ADP (5 μM) resulted in a fall in cAMP which remained higher in the presence of MgS04 (p <0.01).Forskolin (5 μg/ml) and DN9693 (100 μM) also caused increments in platelet cAMP but these responses were not influenced by added MgS04. Addition of ADP resulted in a further increase in cAMP which was augmented by MgS04 (p <0.03). This increase was abolished by adenosine deaminase (1.2 U/ml).These experiments show that MgS04 can modify the cAMP responses produced by iloprost and PGD2 and by forskolin and DN9693 when ADP is present. It appears that as well as inhibiting, ADP can also stimulate cAMP production under certain experimental conditions. This appears to be due to breakdown of ADP to adenosine.
Minimum Fragments of the Heparin Molecule Able to Produce the Accumulation and Change of the Sulfation Pattern of an Antithrombotic Heparan Sulfate from Endothelial Cells
Authors: Pinhal Maria A S , Santos Isabel A N , Silva Irani F , Dietrich Carl P , Nader Helena B 
Published: July 2018

SummaryHeparin and low molecular weight heparins stimulate two to three fold the accumulation of an antithrombotic heparan sulfate secreted by endothelial cells in culture. This led us to search for the minimum structural requirements of the heparin molecule able to elicit the enhancement of the heparan sulfate. Fragments were prepared from heparin by degradation with bacterial heparinase and heparitinases. A heparin pentasulfated tetrasaccharide was shown to be the minimum structural sequence able to enhance two to three fold the secretion of heparan sulfate by endothelial cells. The stimulation is specific for the endothelial cell, is concentration dependent and the effect is already noticed afterone hour of exposure of the cells to heparinand the tetrasaccharide. Degradation of the [35S]-heparan sulfate synthesized in the presence of heparin or the tetrasaccharide has shown a higher degree of sulfation of its iduronic acid residues.
Estimation of the Carbohydrate Moiety of von Willebrand Factor in the Plasma of Patients with Subtypes 2a and 2b of von Willebrand Disease
Authors: Romeuf Christophe de , Samor Bruno , Mazurier Claudine 
Published: July 2018

SummaryVon Willebrand disease (vWD) results from quantitative (types 1 and 3) or qualitative (type 2) deficiency of von Willebrand factor (vWF). This glycoprotein present in plasma is involved in platelet adhesion at the site of vascular injury and serves as the carrier of antihaemophilic A factor (FVIII). Whereas recent studies have identified mutations in patients suffering from type 2 vWD, the integrity of the carbohydrate moiety of vWF in these patients is still matter of debate. In order to analyse in the plasma milieu the carbohydrate content of plasma vWF from various well-characterized type 2 vWD patients, we developed a colorimetric assay in microtiter plate based on the use of peroxidase- conjugated lectins specific for either α 2-6 sialic acid or β 1-4 galactose. Removal of sialic acid from purified plasma vWF induced significant changes in the reactivity of both lectins. The analysis of various normal plasmas showed no influence of the blood groups and allowed us to compare various vWD patients. The reactivity of lectins for plasma vWFs from two type 2A and six type 2B vWD patients harbouring different mutations was not statistically different from that of a pool of normal plasmas. We conclude that the α 2-6 sialic acid and β 1-4 galactose content of plasma vWF is not altered in these patients affected with types 2A and 2B vWD.
Localization of Topically Applied TFPI Binding Sites in an Intimectomized Microvessel
Authors: Ornberg Richard L , Deune Gene E , Ozbek Mustafa R , Wun Tze-Chien , Khouri Roger K 
Published: July 2018

SummaryTissue factor pathway inhibitor, TFPI, has been shown to be highly effective as a topically applied antithrombotic in an arterial model of vascular thrombosis. To elucidate the mechanism and site of TFPI action, recombinant TFPI was conjugated to 30 nm diameter gold particles and used to localize the sites of TFPI binding in a traumatized microvessel by transmission electron microscopy. The model, the central artery of the rabbit ear, was transected, denuded of endothelial lining (intimectomized), and re-anastomosed. Prior to the restoration of blood flow, TFPI-gold or unconjugated gold particles in solution were applied by irrigation to the intimectomized vessel lumen. After 10 min of blood flow, the artery was harvested for electron microscopy. TFPI-gold binding was localized to the fine strands of fibrin that lined the lumen of the intimectomized section of the artery. Little or no binding was found on platelets, exposed smooth muscle, cell membrane fragments, or uninjured vessel segments. The TFPI-gold binding could be competed with native TFPI. TFPI-gold was inhibitory, although less potent than native TFPI, in a prothrombin time assay. Unconjugated gold exhibited very little binding in the vascular model. Hence, the TFPI-gold conjugate behaved like native TFPI. Our observations have identified the fibrin complex as an in vivo binding site for TFPI and suggest that this is an in vivo site of action for TFPI as a topical antithrombotic agent.
The Effects of KBT-3022, a New Anti-platelet Agent, on Hemorheological Properties in Guinea Pigs
Authors: Yamamoto Noriko , Yokota Koichi , Yamashita Akira , Oda Minoru 
Published: July 2018

SummaryUsing guinea pigs, a study was conducted on the effects of KBT-3022, a new anti-platelet agent, on hemorheological properties in various tests including blood filterability, blood viscosity, shear stress-induced red blood cell (RBC) deformability and contents of ATP and 2,3-diphosphoglycerate (2,3-DPG). Oral administration of KBT-3022 at 1 and 10 mg/kg significantly increased blood filterability, and significantly reduced blood viscosity at 10 mg/kg without changing the hematocrit, plasma fibrinogen concentration or plasma viscosity. KBT-3022 (10 mg/kg, p.o.) improved RBC deformability in response to shear stress, which was evoked by passing the blood through a thin tube. This dose of KBT-3022 also increased the contents of ATP and 2,3-DPG in RBC. These findings indicate that KBT-3022 may reduce blood viscosity as a sequel to improvement of RBC deformability through direct action on RBC. The increase in the intracellular levels of ATP and 2,3-DPG was considered to be involved in this improvement of hemorheological properties. These hemorheological effects of KBT-3022 appear to be promising for the treatment of patients with ischemic vascular disease.
A Novel Mechanism for Exposure of Fibrinogen Binding Sites on GPIIb-IIIa by a Monoclonal Antibody
Authors: Hato Takaaki , Watanabe Akito , Nakatani Shingo , Minamoto Yoko , Fujita Shigeru 
Published: July 2018

SummaryConformational changes in platelet membrane glycoprotein (GP) IIb-IIIa, whose nature is not defined, lead to exposure of fibrinogen binding sites. We have reported previously that F(ab’)2fragments of a monoclonal antibody, PMA4, directed against the GPIIb-IIIa complex- specific domain, induced binding of fibrinogen to platelets without causing intracellular activation, whereas Fab did not. In this study, we examined the mechanism responsible for the difference in the ability of PMA4 F(ab’)2and Fab to expose fibrinogen binding sites. PMA4 Fab had affinity for GPIIb-IIIa similar to that of PMA4 F(ab’)2. Addition of F(ab’)2goat anti-mouse Fab antibody to cross-link PMA4 Fab-bound GPIIb-IIIa molecules induced fibrinogen binding. There was a direct correlation between the number of molecules of PMA4 F(ab’)2and the amount of fibrinogen bound. PMA4 did not recognize ligand-induced binding sites (LIBS). These results suggest that the cross-linking of special sites on the GPIIb-IIIa complex-specific domain by bivalent antibody alters the conformation of GPIIb-IIIa to a state competent to bind soluble fibrinogen and that conformational changes in non-LIBS are involved in the mechanism for exposing fibrinogen binding sites on GPIIb-IIIa.