bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Functional Assay of Protein C in Human Plasma and fts Comparison with Amidolytic and Anticoagulant Assays
Authors: Guglielmone H A , Vides M A 
Published: July 2018

SummaryA simple and fast method for the quantitative determination of protein C activity in plasma is here described. The first step consists in the conversion of protein C in the test sample into activated protein C by means of an activator isolated from Southern Copperhead venom. Subsequently, the degradation of factor Va, in presence of protein C-deficient plasma, is measured by the prolongation of the prothrombin time which is proportional to the amount of protein C in the sample. The dose-response curve showed a linear relationship from 6 to 150% protein C activity and the inter- and intra-assay reproducibility was 3.5% and 5.6% respectively. In normal subjects, a mean of protein C level of 98 ± 15% of normal pooled plasma was found. Comparison with the anticoagulant assay in samples of patients with oral anticoagulant, liver cirrhosis, disseminated intravascular coagulation and severe preeclampsia revealed an excellent correlation (r = 0.94, p <0.001). Also, a similar correlation (r = 0.93, p <0.001) existed between amidolytic assay and the method here proposed for all the samples studied without including the oral anticoagulant group. These results allowed us to infer that this method evaluates the ability of protein C to interact with protein S, phospholipids, calcium ions and factor Va.
Modulation of Protein C Inhibitor Activity by Histidine-Rich Glycoprotein and Platelet Factor 4: Role of Zinc and Calcium Ions in the Heparin-Neutralizing Ability of Histidine-Rich Glycoprotein
Authors: Kazama Yoshiaki , Koide Takehiko 
Published: July 2018

SummaryEffects of zinc and calcium ions on the heparin-neutralizing abilities of histidine-rich glycoprotein (HRG) and platelet factor 4 (PF4) were examined. Both HRG and PF4 effectively neutralized the ability of heparin to accelerate the activated protein C (APC) and the thrombin inhibitions by protein C inhibitor (PCI). The heparin-neutralizing ability of HRG in the APC inhibition by PCI, however, was decreased in a Ca2+-dependent manner and apparently lost at 1 mM Ca2+, while it was enhanced by Zn2+ regardless of the presence or absence of Ca2+. The heparinneutralizing ability of HRG in the thrombin inhibition by PCI was not affected by Ca2+.In contrast to HRG, there was no significant difference in the heparin-neutralizing ability of PF4 in the presence or absence of 1 mM Ca2+. These results strongly suggest additional physiological functions of HRG and PF4 as modulators of PCI.
In Vivo Characterization of a New Synthetic Thrombin Inhibitor
Authors: Knabb Robert M , Kettner Charles A , Timmermans Pieter B M W M , Reilly Thomas M 
Published: July 2018

SummaryWe have examined the in vivo pharmacology of DuP 714 (Ac-[D]-Phe-Pro-boroArginine), a representative of a new series of synthetic thrombin inhibitors which contain a boronic acid derivative of arginine. Intravenous bolus injections of DuP 714 in anesthetized rats and conscious rabbits produced transient elevations of clotting times. Clinically relevant prolongations of the APTT were also observed in rabbits after i. v. infusion of less than 0.1 mg kg-1 h-1. Efficacy against venous thrombosis was demonstrated in a rabbit model of stasis induced thrombosis. Clots formed in 100% of control animals and only 33% of animals treated with 0.5 mg/kg DuP 714, and were less severe in treated animals. In a rabbit arterial-venous shunt model mimicking arterial thrombosis, occlusion occurred within 30 min in 72% of control animals vs. 11% of animals treated with 0.1 mg kg-1 h-1 DuP 714. Results indicate that DuP 714 is a highly effective anticoagulant which should be useful for the prevention of both venous and arterial thrombotic diseases.
Daytime Fluctuations of Plasminogen Activator Inhibitor 1 (PAI-1) in Populations with High PAI-1 Levels
Authors: Juhan-Vague I , Alessi M C , Raccah D , Aillaud M F , Billerey M , Ansaldi J , Philip-Joet C , Vague P 
Published: July 2018

SummaryThe mechanism underlying diurnal variations in PAI-1 as well as the cellular origin of PAI-1 in subjects with high PAI-1 levels are unknown. We evaluated diurnal changes (8:00 am vs 4:00 pm) in PAI-1 (functional and immunological assays), t-PA Ag and t-PA/PAI-1 complex levels in controls and subjects with high PAI-1 levels. Three test groups were recruited among obese hyperinsulinmic subjects, emergency care unit patients with inflammatory syndrome or infection and pregnant women.The classical afternoon decrease of PAI-1 level was observed in controls and obese subjects but its amplitude was greater in the latter. The decrease in t-PA Ag and t-PA/PAI-1 complex levels was the same in controls and in obese. As, in previous studies, elevated PAI-1 levels have been correlated with insulin resistance and a decrease in insulin sensibility has been described in the early morning, it is proposed that this “dawn phenomenon” could be implicated in the circadian variations of PAI-1 in controls and could be amplified in obese subjects. Great variability in PAI-1, t-PA Ag or t-PA/PAI-1 complex levels was observed in patients with acute inflammatory syndrome or infection for whom classical biorhythms are suppressed. No diurnal changes in PAI-1 and other fibrinolytic parameters were observed in patients with inflammatory syndrome or in pregnant women suggesting that other sources and/or other regulatory mechanisms of PAI-1 production are involved.
An Enzyme-Linked Immunosorbent Assay for Urokinase-Type Plasminogen Activator (u-PA) and Mutants and Chimeras Containing the Serine Protease Domain of u-PA
Authors: Declerck Paul J , Van Keer Leen , Verstreken Maria , Collen Désiré 
Published: July 2018

SummaryAn enzyme-linked immunosorbent assay (ELISA) for quantitation of natural and recombinant plasminogen activators containing the serine protease domain (B-chain) of urokinase-type plasminogen activator (u-PA) was developed, based on two murine monoclonal antibodies, MA-4D1E8 and MA-2L3, raised against u-PA and reacting with non-overlapping epitopes in the B-chain. MA-4D1E8 was coated on microtiter plates and bound antigen was quantitated with MA-2L3 conjugated with horseradish peroxidase. The intra-assay, inter-assay and inter-dilution coefficients of variation of the assay were 6%, 15% and 9%, respectively. Using recombinant single-chain u-PA (rscu-PA) as a standard, the u-PA-related antigen level in normal human plasma was 1.4 ± 0.6 ng/ml (mean ± SD, n = 27).The ELISA recognized the following compounds with comparable sensitivity: intact scu-PA (amino acids, AA, 1 to 411), scu-PA-32k (AA 144 to 411), a truncated (thrombin-derived) scu-PA comprising A A 157 to 411, and chimeric t-PA/u-PA molecules including t-PA(AA1-263)/scu-PA(AA144-411), t-PA(AA1-274)/scu-PA(AA138-411) and t-PA(AA87-274)/scu-PA(AA138-411). Conversion of single-chain to two-chain forms of u-PA or inhibition of active two-chain forms with plasminogen activator inhibitor-1 or with the active site serine inhibitor phenyl-methyl-sulfonyl fluoride, did not alter the reactivity in the assay. In contrast, inactivation with α2-antiplasmin or with the active site histidine inhibitor Glu-Gly-Arg-CH2Cl resulted in a 3- to 5-fold reduction of the reactivity. When purified scu-PA-32k was added to pooled normal human plasma at final concentrations ranging from 20 to 1,000 ng/ml, recoveries in the ELISA were between 84 and 110%.The assay was successfully applied for the quantitation of pharmacological levels of scu-PA and t-PA(AA87_274)/scu-PA(AA138-411) in plasma during experimental thrombolysis in baboons.Thus the present ELISA, which is specifically dependent on the presence of the serine protease part of u-PA, is useful for measurement of a wide variety of variants and chimeras of u-PA which are presently being developed for improved thrombolytic therapy.
Analysis of the Defective Signal Transduction Mechanism through the Platelet Thromboxane A2 Receptor in a Patient with Polycythemia Vera
Authors: Ushikubi Fumitaka , lshibashi Takafumi , Narumiya Shu , Okuma Minoru 
Published: July 2018

SummaryWe previously reported a patient with polycythemia vera whose platelets showed subnormal responses to thromboxane A2 (TXA2) (Thromb Haemostas 1987; 57: 158-64). The patient’s platelets showed normal binding activity to TXA2 analogues but the generation of second messengers was defective. We further studied the mechanism of this dysfunction in this work. The coupling of TXA2 receptor with its relevant GTP binding protein was examined using STA2(a synthetic TXA2 mimetic)-induced augmentation of GTPase activity as its measure. Only subnormal increase in the GTPase activity of the patient’s platelet membrane was found after STA2 stimulation. Down regulation of TXA2 receptor of the patient’s platelet also showed abnormal behavior. These results suggested that the defective coupling of TXA2 receptor with GTP binding protein could be included as a cause of defective signal transduction in this patient’s platelets. This defect might be due to the abnormality of TXA2 receptor itself if the receptor was down regulated by its phosphorylation through agonist-induced conformational change.
Human Platelets Contain Scinderin, a Ca2+-Dependent Actin Filament-Severing Protein
Authors: Rodríguez Del Castillo A , Vitale M L , Tchakarov L , Trifaró J-M 
Published: July 2018

SummaryA large body of biochemical and morphological evidence suggests that actin polymerizes in response to various stimuli which activate platelets. Previous work has shown the presence in platelets of gelsolin, a Ca2+-dependent regulator of actin filament length. This present work demonstrates that human platelets contain scinderin, another Ca2+-dependent actin filament-severing protein recently discovered in our laboratory. Extracts prepared from platelets were subjected to DNase-I-Sepharose 4B affinity chromatography. EGTA eluates from the affinity columns contained scinderin as demonstrated by mono and two-dimensional polyacrylamide gel electrophoresis and immunoblotting with scinderin antibodies. The concentration of scinderin in platelets was 75 fmol/mg total protein. This might represent 11% of the total actin filament-severing activity if both proteins are equally potent, on a molar basis, in severing actin filaments. Double staining immunocytochemical studies with antibodies against scinderin and rhodamine phalloidin, a probe for F-actin, also demonstrated the presence of scinderin in platelets. These findings suggest that scinderin may participate in the regulation of platelet actin networks.
Normalization of the Haemostatic Plugs of Dogs with Haemophilia A (Factor VIII Deficiency) Following the Infusion of a Combination of Factor Xa and Phosphatidylcholine/Phosphatidylserine Vesicles
Authors: Ni Hong yu , Giles Alan R 
Published: July 2018

SummaryThe bolus intravenous infusion of factor Xa in combination with phosphatidylcholine/phosphatidylserine (PCPS) vesicles, at a dose of 2.6 × 10-11 moles and 4.0 × 10-8 moles/kg body weight respectively, has previously been shown to correct the bleeding diathesis of haemophilic (factor VIII deficient) dogs (Br J Haematol 1988; 69: 491-7). The cuticle bleeding time (CBT) was used as the test to evaluate objectively this response. Transmission electron microscopy was performed to document the evolution of haemostatic plugs forming in the vascular bed of the injured cuticles of both normal and factor VIII deficient dogs with and without treatment with factor Xa/PCPS. The dosage previously shown to normalize the CBT in haemophilic and significantly shorten it in normal animals was used. Subjective and objective observations, using morphometric techniques, were made over a period of 25 min following injury induction. The administration of factor Xa/PCPS was associated with complete and sustained normalization of haemostatic plug development in the haemophiliacs including platelet recruitment, activation and compaction and subsequently fibrinous transformation. In the case of the normals, platelet activation, etc., was exaggerated and fibrinous transformation appeared to be accelerated. The haemostatic plugs forming in the treated haemophiliacs were indistinguishable from those forming in the normals and significantly different, with regard to all parameters measured, from the morphological appearances noted in the untreated haemophiliacs. These data suggest that the correction of the haemostatic defect previously observed results from the normalization of haemostatic plug formation and that this is sustained despite the promotion of systemic fibrinolysis that is also known to occur.
Soluble Fibrin Monomer Complexes Demonstrated by Agarose Gel Filtration and by Adsorption on Insolubilized Fibrinogen
Authors: von Hugo R , Hafter R , Stemberger A , Graeff H 
Published: July 2018

SummaryIncubation of fibrinogen with small amounts of thrombin resulted in the occurrence of soluble fibrin monomer complexes. These complexes consisted predominantly of a derivative with a higher molecular weight than that of fibrinogen. It was characterized by its relative electrophoretic mobility in 5% PAA gel (0.28 × 10-5 cm2/V × sec) and its elution position prior to the fibrinogen peak following gel filtration. Using adsorption chromatography on insolubilized fibrinogen the derivative dissociated at a ratio of almost 1 : 1 into one part which was adsorbed and into fibrinogen which was not adsorbed. The part which was adsorbed seemed to be the thrombin mediated fibrin monomer. This study confirms the concept that dissociable dimeric fibrinogen-fibrin monomer complexes occur after limited action of thrombin on fibrinogen.
The Filtragometer: A New Device for Measuring Platelet Aggregation in Venous Blood of Man
Authors: Hornstra G , ten Hoor F 
Published: July 2018

SummaryA new device for the direct assessment of spontaneous platelet aggregation in human venous blood is described: the Filtragometer. The principle of the method is based on measurement of the pressure difference across a filter with pores of 20 μπι diameter through which blood from a forearm vein is drawn. Platelet aggregates, obstructing the filter, cause a change in the pressure difference which is proportional to the degree of platelet aggregation. The measurement takes only a short time and a small amount (5-10 ml) of blood.Platelet aggregation as measured with the Filtragometer depends on the type of anticoagulant used. The Filtragometer response decreases on inhibition of platelet stickiness in vitro by prostaglandin E1 and in vivo by aspirin ingestion. Moreover it appeared to be higher in a group with a high thrombosis tendency than in a group less susceptible to fatal arterial thrombosis.The Filtragometer seems especially useful in monitoring the results of diet and/or drug therapy.
Maternal Serum FDP and Circulating Fetal Red Cells throughout Pregnancy. A Longitudinal Study
Authors: Hoq M. S , Pepper J , Prescott R. J , Robertson J , Cash J. D 
Published: July 2018

SummaryThe presence of fetal red cells in the maternal circulation and the serum FDP content of 73 women was followed serially throughout a normal pregnancy. There was a significant increase in the mean serum FDP levels in late pregnancy, which was due to episodic elevations occurring in approximately 65% of women. These transient elevations appeared to increase in frequency and severity as pregnancy progressed. There was also an increase in the number of occasions fetal red cells were detected in the maternal circulation in the later months of pregnancy, but this phenomenon did not appear to be associated in any way to the serum FDP elevations. It is concluded that the episodic rises in serum FDP occurring in normal pregnancy are not related to episodes of occult disseminated intravascular coagulation secondary to placental haemorrhage as was previously hypothesized. Their etiology and clinical significance remain unknown.
Adverse Effect of Heparin in Thrombin-Antithrombin III Interaction
Authors: Marciniak Ewa 
Published: July 2018

SummaryThrombin, while reacting in the presence of heparin, impairs the inhibitory capacity of antithrombin III so that subsequent inhibition of thrombin or factor Xa is decreased or abolished. This adverse effect of heparin has been observed directly with at least 1.5 Iowa units of thrombin per each unit of purified human antithrombin III participating in the reaction. The inhibitory capacity was then totally destroyed and some residual thrombin remained in the active form. With a lower enzyme/inhibitor ratio inactivation of thrombin in the presence of heparin was fast and complete, however, a significant decrease of inhibitory capacity below that found in reaction without heparin, has been established by measuring the residual antithrombin III activity. In defibrinated human plasma at least 2 units of thrombin per each antithrombin III unit were required to demonstrate directly the adverse effect of heparin, but a fast depletion of inhibitory capacity has been also observed after repeated additions of small thrombin portions into plasma heparinized in vitro or in vivo. Portions of enzyme initially added disappeared with great velocity; subsequent portions, however, accumulated building up a high thrombin level not seen in the absence of heparin. The accumulation of residual enzyme was more extensive in plasma containing about 1 heparin unit per ml than anticoagulant at lower concentrations and was particularly noticeable in antithrombin III deficient plasma. These results may have some bearings on the approach to heparin therapy in the event when thrombin continuously generates or when a marked deficiency of antithrombin III exists.
Einfluß von Zytostatik auf das Gerinnungssystem
Authors: Fellin F. M. , Barsigian C. , Martinez J. , Base W. 
Published: July 2018

ZusammenfassungZytostatika werden sehr viel in der Behandlung von Malignomen verwendet. Blutungskomplikationen und thrombotische Ereignisse treten bei Patienten mit Karzinomen entweder durch die Krebserkrankung selbst oder aufgrund der Behandlung der Krebserkrankung auf. Die Mechanismen für die thrombotischen und hämorrhagischen Syndrome sind bisher noch unzureichend untersucht. Diese Arbeit gibt eine Übersicht der wesentlichen thrombotischen und hämorrhagischen Zustände, die sich aus der Anwendung antineoplastischer Substanzen ergeben, und versucht eine Darstellung des gegenwärtigen Wissensstandes der Pathophysiologie dieser Zustände.
Wrist Swelling in Kienböck's Disease
Authors: Ichinose Hirofusa , Nakao Etsuhiro , Shinohara Takaaki , Tatebe Masahiro , Yamada Harumoto , Nakamura Ryogo 
Published: July 2018

Background and Purpose Wrist swelling is a frequent clinical manifestation of Kienböck's disease, but no study has reported the site and pathology of wrist swelling in this disease. The aim of this study is to elucidate the site and pathology of wrist swelling in Kienböck's disease.
Materials and Methods Dorsal and palmar soft tissue thicknesses of the wrist were measured on standard lateral radiographs of the wrist in 26 patients with Kienböck's disease and 30 subjects without intra-articular lesion. Axial magnetic resonance imaging (MRI) views were examined to detect the site of swelling. The dorsal capsular ligament in three patients with Kienböck's disease underwent histological examination.
Results Radiographic study confirmed dorsal wrist swelling in 24 of 26 (92%) patients examined compared with the contralateral unaffected wrists. MRI demonstrated thickening of the dorsal capsular ligament and extensor layer with synovial proliferation. Histological examination revealed nonspecific chronic inflammation.
Conclusion Dorsal wrist swelling in Kienböck's disease is a common manifestation and constitutes a part of pathology of Kienböck's disease, although further study is required to clarify the relation between wrist swelling and etiology of Kienböck's disease.
Level of Evidence This is a Level III study.
Short-Term Results after Total Trapeziectomy with a Poly-L/D-Lactide Spacer
Authors: Kestens Bart , Van Laere Sven , Goubau Jean , Goorens Chul , Van Royen Kjell 
Published: July 2018

Background Proximal migration of the first metacarpal can be seen after total trapeziectomy and various techniques have been described to prevent this subsidence.
Purpose We hypothesized the insertion of a poly-L/D-lactide spacer to prevent proximal migration of the first metacarpal without the need of an additional ligament reconstruction, allowing early mobilization and less demanding rehabilitation.
Patients and Methods Ten thumbs were treated with a total trapeziectomy and insertion of a poly-L/D-lactide scaffold. Clinical and radiological evaluation was performed after 6 months and 1 year. Patient satisfaction, pain, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score, mobility of the thumb, and strength were assessed.
Results Pain according to the visual analog scale decreased (p = 0.01) and QuickDASH score decreased (p = 0.02) significantly after 1 year. Radiological evaluation after 12 months showed a collapse of the scaphometacarpal distance of 45% (p = 0.01). Osteolysis of the distal scaphoid pole and/or proximal metacarpal was seen in 6 out of 10 cases. Because of the osteolysis, the use of the poly-L/D-lactide scaffold was discontinued in our practice.
Conclusion In this limited series, total trapeziectomy with the use of the poly-L/D-lactide scaffold provides significant pain reduction and improvement of overall function. Radiographic evaluation shows significant collapse of the scaphometacarpal distance after 1 year and frequent signs of osteolysis. We do not encourage the use of the poly-L/D-lactide scaffold with total trapeziectomy before long-term clinical and radiological follow-ups of the osteolysis are available.
Hydro-social metabolism: scaling of birth rate with regional water use
Authors: Pande Saket , Pandit Akshay 
Published: July 2018

AbstractPopulation growth is often intuitively linked with proportionally higher use of fresh water resources. However, this implies that water use per capita does not change with population growth. We not only find that birth rates of regions are negatively related with its water use per capita (i.e., higher birth rate is associated with lower water use), but also that birth rates scale with the latter with a negative power. We use population and water withdrawal data from 1950 to 2005 at irregular 5-year intervals; with virtual water content, virtual water trade and agricultural production data from 1960 to 2000 for the seven continents to investigate the scaling relationship and interpret it through the lens of metabolism theory. Our analysis reveals that the scaling exponent lies between −1/3 and −1/2. Deviations from the power relationship are observed for Europe and Africa, which are attributed to lower than expected and higher than expected birth rates, respectively. Europe’s deviation from the average scaling relationship may be due to the higher rate of return on human capital in industrialized countries. But why Africa deviates, while other developing and developed regions follow the power relationship more closely, remains a puzzle.