bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Prostacyclin and of the Stable Prostacyclin Analogue ZK 36374 on Forearm Blood Flow and Blood Platelet Behaviour in Man
Authors: Cowley A J , Heptinstall S , Hampton J R
Published: July 2018

PGI2 and ZK 36374 were each infused into volunteers and the effects on forearm blood flow and on platelet behaviour were determined. Infusions of PGI2 or ZK 36374 did not alter resting forearm blood flow but both agents reduced the extent of the vasoconstriction that occurred in response to cold. ZK 36374 appeared to be a much more potent inhibitor of platelet behaviour than PGI2 when blood was taken while the infusions were in progress, but the effects of both agents were no longer evident one hour after the infusions were terminated. There was an inverse relationship between the extent of cold-induced vasoconstriction and the concentration of sodium arachidonate that was needed to induce platelet aggregation for different individuals. Infusions of PGI2 affected both parameters equally but ZK 36374 had a greater effect on platelet behaviour than on blood flow. It is possible that very low doses of ZK 36374 would result in inhibition of platelet behaviour without producing adverse haemodynamic effects.
The Electrophoretic Mobility Heterogeneity of Human Platelet Subpopulations of Different Buoyant Densities
Authors: Jung Stephanie M , Tanoue Kenjiro , Yamazaki Hiroh
Published: July 2018

Human platelets were separated into density subpopulations by using a step-wise gradient of Percoll in Tris-NaCl buffer. The absolute value of the electrophoretic mobility (EPM) of the density subpopulations was found to be a linear function of the density of the platelets, with EPM becoming less negative with increasing platelet density. Platelet volume distributions, mode volume, and sialic acid and protein contents were found to increase with platelet density, while no differences were found in GPU, GPIII, and GPIV contents among the subpopulations. An estimate of charge density was made from the ratio between the PAS-staining material (membrane GP’s) and platelet surface area. The ratio was found to decrease as platelet density increased, consistent with the less negative EPM values observed for the higher density platelets. This lower surface charge of heavier platelets, which would lower charge repulsion between cells, agrees with the premise that heavier platelets are more active.
Platelet Activation in Psoriasis
Authors: Berrettini Mauro , Parise Pasquale , Costantini Vincenzo , Grasselli Serena , Nenci Giuseppe G
Published: July 2018

Recent epidemiological studies have suggested that psoriasis represents a risk factor for thrombotic vascular diseases. In order to evaluate the possible role of hemostatic changes in the development of thrombotic episodes in psoriasis, some parameters of the hemostatic “balance” were investigated in 22 male psoriatic patients and compared to those of 22 male control subjects. Incidence of known risk factors for vascular diseases (diabetes, hypertension, smoking, dyslipidemia) was comparable in the two study groups. There were no statistically significant differences in platelet count, circulating platelet aggregates, platelet production of malondialdehyde (MDA), total plasma anti thrombin and fibrinolytic activities. In patients with psoriasis the incidence of spontaneous platelet hyperaggregability and plasma levels of β-thromboglobulin were significantly higher than in control subjects. Platelet regeneration time, measured as MDA recovery after aspirin ingestion, was significantly shorter in psoriatic patients. These data suggest that an in vivo platelet activation occurs in patients with psoriasis and could contribute to the development of thrombotic complications. The release of mitogenic and inflammatory substances by activated platelets may play a role in the histogenesis of psoriatic lesions.
Determination of Plasma Protein S - The Protein Cofactor of Activated Protein C
Authors: Bertina R M , van Wijngaarden A , Reinalda-Poot J , Poort S R , Bom V J J
Published: July 2018

Protein S, an important cofactor of activated protein C, and C4b-binding protein were purified from human plasma. Specific antibodies against the purified proteins were raised in rabbits and used for the development of immunologic assays for these proteins in plasma: an immunoradiometric assay for protein S (which measures both free protein S and protein S complexed with C4b-binding protein) and an electroimmunoassay for C4b- binding protein. Ranges for the concentrations of these proteins were established in healthy volunteers and patients using oral anticoagulant therapy. A slight decrease in protein S antigen was observed in patients with liver disease (0.78 ± 0.25 U/ml); no significant decrease in protein S was observed in patients with DIC (0.95 ± 0.25 U/ml).

Criteria were developed for the laboratory diagnosis of an isolated protein S deficiency
An Inhibitor to Factor VIII: C in a Patient with Possible Combined Haemophilia A and von Willebrand’s Disease
Authors: Taylor L D , Dean F L , Tiedemann K , Ekert H
Published: July 2018

A factor VIII inhibitor has been found in a patient with an unusual combination of factor VIII-related properties. The inhibitor is directed specifically against the clotting activity (VIII :C) of the factor VIII complex. It behaves in a similar fashion to high responding inhibitors of factor VIII seen in haemophilia A patients and it was characterised as an immunoglobulin of the IgG class. Laboratory results from the patient and his family show considerable variation of factor VUI-related properties between various individuals. Overall, the data suggests the co-existence of haemophilia A and von Willebrand’s disease in the family and the presence of both diseases in the patient.
Binding of Various Thrombin Fractions to Fibrin and the Influence of AT-III on Their Adsorption
Authors: Nilsen D W T , Brosstad F , Kierulf P , Godal H C
Published: July 2018

Human thrombin with high affinity for fibrin was obtained by subjecting purified thrombin to affinity chromatography on Sepharose insolubilized fibrin monomers, after addition of a radioiodinated subsample of thrombin, molar ratio 1:600. As judged by radioprofiling of the electrophoretic distribution of high-affinity thrombin on 10 per cent polyacrylamide gel containing urea/SDS, the preparation consisted of 70 per cent a-thrombin, 28 per cent β-thrombin and only 2 per cent γ-thrombin. Although a-thrombin was bound more strongly to insolubilized fibrin monomers than the other subfractions, complete separation of the individual components could not be achieved.

High-affinity thrombin was employed for studies on thrombin adsorption to polymerized fibrin, assuming equal behaviour of labelled and unlabelled thrombin.

o avoid passive entrapment of thrombin within the fibrin meshwork at physiological pH, ionic strength and calcium concentration, the optimal fibrinogen concentration was found to be 2.94 umol/1. During such conditions, adsorption of thrombin to polymerized fibrin did not exceed 65 per cent of added thrombin, despite an increasing availability of fibrin-related thrombin binding domains obtained by reducing the thrombin concentration.

Adsorption of thrombin to polymerized fibrin increased by 25 per cent when the ionic strength was reduced to 0.05 mol/1. These findings suggest the presence of thrombin subfractions with different affinities for polymerized fibrin.

Aggregates of high-affinity thrombin formed during its preparation by affinity chromatography, but were prevented by adding polyethylene glycol (m.w. 6,000, final conc. 6.6 g/1). Such aggregates were not inactivated by AT-III, but could still adsorb to polymerized fibrin.

In its monomeric form fibrin-adsorbed thrombin was inactivated by AT-III and could then be extruded from the clot upon syneresis and retraction, but a small fraction remained attached to polymerized fibrin, exhibiting minor amidolytic activity.
Increased Plasma Noradrenaline During Severe Sodium Restriction Does Not Stimulate Platelet Release in Essential Hypertension
Authors: Kjeldsen S E , Lande K , Gjesdal K , Jackson M B , Westheim A , Frederichsen P , Leren P , Eide I
Published: July 2018

Seventeen 50-year old hypertensive men, previously untreated with blood pressure 157 ± 4/110 ± 2 mmHg (means ± SE) were given a low sodium diet for 2 weeks. During the second week, the diet was supplemented with potassium. The urinary Na+/K+ excretion ratio changed from 2:1 to 1:4 and 1:11, respectively.

Sympathetic noradrenergic tone increased considerably during the first week. Thus, venous plasma noradrenaline increased from 254 ± 22 to 347 ± 28 pg/ml (p <0.001) and arterial concentration from 253 ± 36 to 317 ± 42 pg/ml (n = 10, p <0.001). No significant change was observed in sympathetic adrenal tone as reflected by normal plasma adrenaline in venous (42 ± 5 vs 43 ± 6 pg/ml, ns) or arterial blood (71 ± 10 vs 82 ± 15 pg/ml, n = 10, ns) or in venous plasma concentration of the blood platelet release product beta-thromboglobulin (BTG) (50 ± 8 vs 43 ± 5 ng/ml, ns). During the second week sympathetic noradrenergic tone remained highly significantly elevated compared to baseline but still no change in plasma adrenaline or plasma BTG was found.

Thus, whereas sodium depletion did increase plasma noradrenaline concentration markedly in these hypertensive men, no change in adrenaline concentration was observed, and blood platelet release reaction was unchanged. Plasma noradrenaline within the physiological concentration range does not seem to serve as a regulator of in vivo platelet function.
An Enzyme-Linked Immunosorbent Assay (ELISA) for the Measurement of Plasmin-α2-Antiplasmin Complex in Human Plasma - Application to the Detection of In Vivo Activation of the Fibrinolytic System
Authors: Holvoet Paul , Boer Auke de , Verstreken Maria , Collen Désiré
Published: July 2018

An enzyme-linked immunosorbent assay (ELISA) is developed for the measurement of plasmin-α2-antiplasmin complex in human plasma. Microtiter plates were coated with a mixture of two murine monoclonal antibodies directed against human α2-antiplasmin and bound plasmin-α2-antiplasmin complex was quantitated with a peroxidase-conjugated monoclonal antibody directed against human plasminogen. The lower limit of sensitivity of the assay was 0.01 nM of plasmin-α2-antiplasmin complex in 100-fold diluted human plasma, allowing detection of 1 nM in undiluted plasma samples. After 100-fold dilution of the plasma samples, the assay was no longer influenced by the presence of the precursors plasminogen and α2-antiplasmin.

At a concentration of 2.0 nM of plasmin-α2-antiplasmin complex in plasma, intra- and interassay variation coefficients were 4.2 and 5.5 percent respectively. In plasma samples of 25 control subjects the levels of plasmin-α2-antiplasmin complex were below 1 nM. Extensive in vivo activation of the fibrinolytic system during thrombolytic therapy with streptokinase resulted in the generation of elevated levels of plasmin-α2-antiplasrnin complex up to 690 ± 150 nM.

No measurable levels of plasmin-α2-antiplasmin complex were found in the plasma of 32 patients with acute deep vein thrombosis nor in the plasma of 11 patients with recurrent deep vein thrombosis.

These findings indicate that plasmin-α2-antiplasmin complex is generated during in vivo activation of the fibrinolytic system and that its assay may be useful to monitor thrombolytic therapy but not for the diagnosis of venous thrombosis.
Aggregation of Washed Platelets from Non-Anticoagulated Human Blood Is Not Reversible
Authors: Bowry S K , Müller-Berghaus G
Published: July 2018

Most of the knowledge acquired on platelet function and biochemistry has been obtained from platelets prepared from blood anticoagulated with sodium citrate. Using washed platelets from human blood (PNB) to which no anticoagulants were added, we report on responses not observed with platelets prepared from citrate-anticoagulated blood. Native blood was passed rapidly (within 5 min of venepuncture) through a Sephadex G-25/G-50 column to remove divalent ions and thus prevent coagulation. Platelets were separated from the gel-filtered blood by differential centrifugation. Responses of PNB to thrombin, collagen, calcium ionophore, ristocetin, release of 14C-5hydroxytryptamine and p-thromboglobulin, and generation of thromboxane A2 were similar to those observed for citrated platelets. Comparison of PNB with thrombin-treated platelets, which demonstrate an increase of platelet factor 3 activity, a reduction of the adenylate energy charge and an impairment of clot retraction, indicated the absence of platelet activation. Unlike citrated platelets, however, aggregation of PNB in response to ADP was irreversible in the presence of Ca2+ and fibrinogen, even at concentrations as low as 0.2 μM ADP, with aggregation taking up to 25 times longer to reach the same extent of aggregation as for citrated platelets. PNB did not aggregate to epinephrine even in the presence of Ca2+ and fibrinogen. Sodium citrate impaired ADP-induced aggregation and clot retraction of PNB. Thus citrate affects platelet function and may cause changes resulting in the unphy-siological behaviour and responses of platelets.
Urinary Beta-Thromboglobulin Correlates with Impairment of Renal Function in Patients with Diabetic Nephropathy
Authors: Hopper A H , Tindall H , Davies J A
Published: July 2018

TBeta-thromboglobulin (βTG) is a platelet-specific protein and since its concentration in plasma rises when platelets are activated, it has been used as an indicator of platelet involvement in vascular disease. Since platelets might be involved in the pathogenesis of diabetic microvascular disease we measured urinary βTG in 20 insulin-dependent diabetics with nephropathy and compared the results with those from 20 normal subjects. Measurement of βTG in urine was undertaken to avoid errors induced by blood sampling and to gain information over a prolonged period using a single assay. Measurements were made of βTG, β2-microglobulin and total protein in urine collected for 24 h and creatinine and β2 microglobulin in plasma. Survival of indium-111-labelled platelets was measured in nine patients. Urinary PTG was significantly (p <0.02) increased in the 20 patients compared with 20 normal volunteers (median value 1.3 vs 0.8 μg/24 h). There was a strong correlation between urinary βTG excretion and plasma creatinine concentration (r = 0.8, p <0.0001) and plasma β2-microglobulin concentration (r = 0.9, p <0.0001). Urinary βTG concentration did not correlate with platelet survival. The results indicate that although urinary βTG is significantly increased in patients with diabetic nephropathy its concentration in urine correlates with indicators of glomerular filtration rather than with a test of platelet activation.
An Enzyme Immunoassay (ELISA) for the Quantitation of Human Factor VII
Authors: Boyer C , Wolf M , Rothschild C , Migaud M , Amiral J , Mannucci P M , Meyer D , Larrieu M J
Published: July 2018

A new solid phase enzyme-linked immunosorbent assay (ELISA) was developed for the quantitation of human Factor VII antigen (F VII Ag), using a monospecific rabbit anti-F VII antiserum. Anti-F VII F(ab′)2 fragments were adsorbed to polystyrene plates. The binding of serial dilutions of control or test plasma, containing F VII, was detected by incubation with peroxidase-labeled anti- FV II IgG followed by the addition of hydrogen peroxyde and O-phenylenediamine. This ELISA is specific, sensitive (detection limit: 0.05%) and accurate (coefficient of variation: 1.5-4% for within- and 1.6-9% for between-assays). F VII coagulant activity (F VII C) and F VII Ag were determined in large populations of controls and patients. In normal plasma (n = 38), F VII Ag ranged from 83 to 117% and the correlation coefficient between F VII Ag and F VII C was 0.94. In patients with severe (F VII C inf. 1%) congenital F VII deficiency (n = 5), F VII Ag was undetectable in two cases (inf. 0.05%) and markedly reduced (0.35 to 5.6%) in the three other cases. In patients with liver cirrhosis (n = 15), F VII Ag ranged from 21 to 59% and was in good correlation with F VII C (r = 0.84). In dicoumarol treated patients (n = 15), the levels of F VII Ag ranged from 51% to 79% and a poor correlation (r = 0.52) with F VIIC was observed. In “compensated” DIC (n = 5), levels of F VII Ag varied from 60 to 186%, with significantly higher F VII C levels (from 143 to 189%). In contrast, in “decompensated” DIC (n = 7), low F VII Ag and F VII C levels were observed (from 7 to 27%). In patients with deep-vein thrombosis (n = 25), high levels of F VII Ag (from 102 to 136%) and F VII C (from 110 to 150%) were demonstrated. In surgical patients, no significant difference was observed before and one day after intervention.
Effect of Pentosan Polysulphate Administration in Man on the Formation of Covalent Complexes Between Heparin Cofactor II and Thrombin Generated in Plasma by Contact Activation
Authors: Dol F , Sié P , Dupouy D , Boneu B
Published: July 2018

An assay for the quantification of pentosan polysulphate (PPS) in plasma is described. As PPS has been shown to potentiate thrombin inhibition by the second heparin cofactor (HC II), the principle of this assay was to measure the formation of covalent complexes between HC II and the thrombin generated in plasma after contact activation and recalcification. The complexes were quantified by using purified 125I-HC II added to the plasma as a tracer and SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The assay was sensitive to low PPS concentrations (limit of detection: 0.1 μg/ml) and therefore suitable for the measurement of PPS in plasma after its administration to man.

The clearance of PPS was studied in 3 subjects receiving respectively 10, 50 and 100 mg intravenously (IV) and in 3 subjects receiving 35 mg subcutaneously (SC). PPS was still detectable 8 h after 50 and 100 mg IV and 6 h after 35 mg SC. The activated partial thromboplastin time (APTT) was, in comparison, relatively insensitive but for concentrations above 1 μg/ ml the values derived from the APTT and from the SDS-PAGE method fitted. The results were also in general agreement with those reported by McGregor et al. (5) who used a sensitive competitive binding assay. This indicates that low concentrations of PPS previously measured chemically are also pharmacologically active in plasma.
Haemophilia B Leyden in Greece
Authors: Mandalaki T , Louizou C , Dimitriadou C , Briët E
Published: July 2018

In this paper, a five generation Greek family is described with haemophilia B. The disease is characterized by a normal ox-brain prothrombin time, normal levels of the vitamin-K dependent clotting factors VII and X and a proportional reduction of factor IX acttivity and antigen levels all of which is consistent with the cross-reacting material negative form of haemophilia B. However, in this family the factor IX levels in the three patients of generation V are around 1 U/dl while the three older patients in generation III have factor IX levels ranging from 28 to 44 U/dl. In the oldest patient of generation V we observed a rise of the factor IX level from 1 U/dl up to the age of 13 to 10 U/dl at age 14. In addition, the older patients have very mild bleeding symptoms or none at all, while the young ones have occasional spontaneous haemorrhages in muscles and joints, compatible with severe or moderately severe haemophilia. The disease appears to be similar to haemophilia B Leyden which has been described in a Dutch family.
Evaluation of p-Amidinophenyl Esters as Potential Antithrombotic Agents
Authors: Pizzo Salvatore V , Turner Denise , Porter Ned A , Gonias Steven L
Published: July 2018

Three p-amidinophenyl esters have been synthesized and characterized as irreversible inhibitors of the vitamin-K dependent proteinases; factors IXa, Xa and thrombin (Turner et al. [4])+. In the present report we describe the in vitro and in vivo effects of these agents on standard coagulation tests in vitro and in blood from animals treated with the compounds. At a concentration of 500 μM, the three esters increased the activated partial thromboplastin time (PTT) of pooled human plasma 3 to 5-fold. The prothrombin time increased 1.4 to 3.7-fold under similar conditions. The p-amidinophenyl ester of cinnamic acid (CINN) showed the most pronounced effect on both assays. This ester also is the best inhibitor of human factors IXa and Xa, while the p-amidinophenyl ester of benzoic acid (BENZ) is a slightly better α-thrombin inhibitor (4). The effect of these esters on the thrombin clotting time correlated with in vitro kinetic measurements of α-thrombin inhibition rates. Both BENZ and CINN increased the assay endpoint more than 6-fold. The three esters also were studied using mouse plasma. A comparable effect on the PTT was noted. Intravenous administration of 300 αl of 1 mM CINN as a single bolus in mice caused a 2.3-fold increase in the PTT which remained 1.2-fold normal 2 h later. The BENZ and a-methyl-cinnamic acid (MECINN) esters were somewhat less effective as predicted from their in vitro effect on the PTT. This investigation and previous studies indicate that these compounds demonstrate low toxicity at therapeutic levels. It is concluded that the p-amidinophenyl esters may be useful in antithrombotic therapy.
Gel Filtration Patterns of Factor VIII Coagulant Antigen and Factor VIII Related Antigen in Normal and von Willebrand’s Disease
Authors: Chediak Juan , Peake Ian , Bloom Arthur
Published: July 2018

Gel filtration (sepharose 2B CL) patterns of factor VIII coagulant antigen (VIIIC :Ag) and factor VIII related antigen (VIIIR: Ag) were obtained using normal plasma and plasma from patients with von Willebrand’s disease. The latter group consisted of five individuals with normal mobility of factor VIIIR :Ag on cross-immunoelectrophoresis (Type I) and five others with abnormal (increased) mobility (Type II). Results showed that the elution of VIIIC: Ag was delayed in those subjects whose ratio of VIIIR :Ag to VIIIC :Ag was reduced. It has previously been reported that VIIIR :Ag exerts a stabilizing influence on the coagulant activity of factor VIII (VIII: C); our data suggests that when VIIIR :Ag is deficient, abnormal (low molecular weight) forms of VIIIC: Ag circulate.
The Ability of Fibrinogens, FI and FII, to Support ADP- Induced Platelet Aggregation
Authors: Phillips H M , Mansouri A , Perry C A
Published: July 2018

Fibrinogen plays an integral part in ADP-induced platelet aggregation. Controversy exists in regard to the role of the carboxy termini of fibrinogen Aa chains in this reaction. We have attempted to clarify this problem in view of the availability of a highly purified FII fibrinogen fraction. Kabi fibrinogen or its purified fractions FI, FII and FIII-IV-V were added to washed platelets in the presence of Tyrode-HEPES buffer pH 7.4. Aggregation was initiated by the addition of calcium and ADP. These fibrinogen fractions equally promoted ADP-induced platelet aggregation. The major difference among these fractions is in their Aα chains. The FI fraction contains intact Aα chains while FII and FIH-IV-V fractions have one and two partially degraded Aα chains at the carboxy terminal portion respectively. We conclude that the carboxy terminal portion of the Aα chain does not play an important role in promoting ADP-induced platelet aggregation.
Functional and Antigenic Antithrombin III Values in Plasma and Serum from 115 Regular Blood Donors and Antithrombin III In Prediction of Postoperative Thrombosis
Authors: Nilsen D W T , Jeremic M , Weisert O K , Fønstelien E , Godal H C
Published: July 2018

Antithrombin III (AT-III) was determined functionally using chromogenic substrate (S-2238) and immunologically using radial immunodiffusion (RID) in plasma and serum from 115 blood donors. There was a decrease in functional activity by 43.5% and in antigen concentration by 18.4% during in vitro coagulation when corresponding serum and plasma samples were compared. A positive correlation was found between the two methods in plasma (r=0.784) as well as in serum (r = 0.658). RID in serum correlated well with RID in plasma (r = 0.811), but the correlation for S-2238 in plasma and serum was poor (r = 0.411). Functional AT-III decrease during coagulation was uncorrelated with age and fibrinogen, and was not statistically affected by sex, smoking or blood groups.

Preoperative functional AT-III activity was measured in 25 patients undergoing elective hip replacement, 60% of whom developed postoperative thrombosis. The functional activity in serum discriminated well between the thrombotic and nonthrombotic group of patients (p<0.025), whereas the activity in plasma showed only a minor difference.
1-O-Hexadecyl-2-Acetyl-SN-3-Glycerophosphoryl- choline (PAF): Some Effects on the Aggregation of Human Platelets by Thrombin or Collagen
Authors: Hornby Edward J , Perry Colin R
Published: July 2018

1-O-hexadecyl-2-acetyl-sn-3-glycerophosphorylcholine (PAF) was examined as a potential mediator of aggregation induced by thrombin or high concentrations of collagen in indomethacin treated platelet rich plasma by investigating the response to collagen and thrombin of platelets previously desensitised to PAF. No reduction in the response to collagen or thrombin was observed and it was concluded that PAF was not a mediator of non-prostanoid dependent aggregation in platelets exposed to thrombin or collagen.
Enhancement of the Release Reaction Not Accompanied with Enhanced Phosphatidylinositol Turnover in the Reserpinized Rabbit Blood Platelets
Authors: Watanabe Y , Soda M , Fukamachi N , Kobayashi B
Published: July 2018

Thrombin-induced platelet release reaction examined with secretion of calcium and N-acetylglucosaminidase was significantly enhanced in the platelets from reserpine-treated rabbits as compared with the control. On the other hand, 32P-incorporation into phosphatidic acid was suppressed in the reserpinized platelets in activated state. Thrombin induced phosphatidylinositol (PI)- breakdown, which was examined by decreases in radioactivity and content of PI, and an increase in diacylglycerol, was not enhanced in the reserpinized platelets as compared with the control. The phosphorylation of the specific protein coupled to thrombin- induced platelet PI-breakdown was not stimulated in the reserpinized platelets as compared with the control. In contrast to PI, PC-degradation by thrombin was significantly stimulated in the reserpinized platelets. Possible existence of pathway(s) other than that associated with an enhancement of Pl-tumover is conceivable as a mechanism involved in platelet release reaction.
Inactivation of Thrombin by the Aortic Endothelium
Authors: Swedenborg J , Dryjski M , Olsson P
Published: July 2018

The aim of the investigation was to clarify the uptake of thrombin on vascular endothelium and the inhibition of thrombin on the endothelium in the presence or absence of plasma. Segments of porcine aorta were used. Thrombin was labelled with 125I and its enzymatic activity was assayed amidolytically using a specific chromogenic substrate. After exposure to the endothelium both enzymatic activity and radioactivity disappeared from the thrombin solution and were recovered as surface bound activities.

The enzyme activity confined to the endothelium rapidly disappeared in the presence of plasma but no activity was recovered in the plasma. The surface confined radioactivity, however, decreased slowly and was quantitatively recovered in the plasma. In the absence of plasma, i. e. in the presence of a balanced Ringer’s solution, only slow disappearance of thrombin enzymatic activity occurred although the rate of disappearance was higher than that of release of radioactivity.

It is concluded that thrombin, taken up on the endothelium, is almost instantaneously inhibited by an interaction mechanism with plasma and then released in an inactive state. The endothelium itself, however, seems to slowly inhibit bound thrombin and then release it.
Standardization of Factor VIII – IV. Establishment of the 3rd International Standard for Factor VIII: C Concentrate
Authors: Barrowcliffe T W , Curtis A D , Thomas D P
Published: July 2018

An international collaborative study was carried out to establish a replacement for the current (2nd) international standard for Factor VIII: C, concentrate. Twenty-six laboratories took part, of which 17 performed one-stage assays, three performed two-stage assays and six used both methods. The proposed new standard, an intermediate purity concentrate, was assayed against the current standard, against a high-purity concentrate and against an International Reference Plasma, coded 80/511, previously calibrated against fresh normal plasma.

Assays of the proposed new standard against the current standard gave a mean potency of 3.89 iu/ampoule, with good agreement between laboratories and between one-stage and two- stage assays. There was also no difference between assay methods in the comparison of high-purity and intermediate purity concentrates. In the comparison of the proposed standard with the plasma reference preparation, the overall mean potency was 4.03 iu/ampoule, but there were substantial differences between laboratories, and the two-stage method gave significantly higher results than the one stage method. Of the technical variables in the one-stage method, only the activation time with one reagent appeared to have any influence on the results of this comparison of concentrate against plasma.

Accelerated degradation studies showed that the proposed standard is very stable. With the agreement of the participants, the material, in ampoules coded 80/556, has been established by the World Health Organization as the 3rd International Standard for Factor VIII :C, Concentrate, with an assigned potency of 3.9 iu/ampoule.
The Effects of Age, Gene Source and Familial Severity on Factor VIII in Normals and Haemophilia Carriers: Analysis by Multiple Regression
Authors: Duncan Bruce M , Tunbridge Lynn J , Lloyd John V
Published: July 2018

There are conflicting views on the effects of age, gene source and familial severity on levels of factor VIII in carriers of haemophilia. Different workers have found that factor VIII increases with age, is higher in paternal carriers, and is higher in carriers from families with more severe haemophilia. Other workers have disagreed with these findings. In this study we explored some of the causes of this conflict. We measured factor VIII related antigen and factor VIII coagulant activity on 40 normal females and 48 carriers, and analysed the results by multiple regression and analysis of covariance. Our results indicated that both factor VIII coagulant activity and factor VIII related antigen increased with age, but were unaffected by the familial severity of haemophilia or whether the defective gene came from the mother or the father. We found that the conflicting reports of previous authors were due to high inter-correlations of the studied variables.
Interaction of Human Tumor Cells with Human Platelets and the Coagulation System
Authors: Al-Mondhiry Hamid , McGarvey Virginia , Leitzel Kim
Published: July 2018

This paper reports studies on the interaction between human platelets, the plasma coagulation system, and two human tumor cell lines grown in tissue culture: Melanoma and breast adenocarcinoma. The interaction was monitored through the use of 125I- labelled fibrinogen, which measures both thrombin activity generated by cell-plasma interaction and fibrin/fibrinogen binding to platelets and tumor cells. Each tumor cell line activates both the platelets and the coagulation system simultaneously resulting in the generation of thrombin or thrombin-like activity. The melanoma cells activate the coagulation system through “the extrinsic pathway” with a tissue factor-like effect on factor VII, but the breast tumor seems to activate factor X directly. Both tumor cell lines activate platelets to “make available” a platelet- derived procoagulant material necessary for the conversion of prothrombin to thrombin. The tumor-derived procoagulant activity and the platelet aggregating potential of cells do not seem to be inter-related, and they are not specific to malignant cells.
Effect of Neutral Proteases from Blood Leukocytes on Human Platelets
Authors: Bykowska K , Kaczanowska J , Karpowicz M , Stachurska J , Kopeć J
Published: July 2018

Two highly purified neutral proteases from human leukocytes i.e. elastase-like protease (ELP) and chymotrypsin-like protease (CLP) do not destroy human platelets since no difference was found in 51Cr liberation from control and enzyme-treated platelets. As with pancreatic chymotrypsin (α-CT) ELP does not induce the release of 3H-serotonin while CLP provokes 3H- serotonin secretion, in an enzyme concentration and time dependent fashion. The rate and degree of 3H-serotonin release by CLP is similar to that produced by thrombin. Incubation of platelets at 37° C for 30 min with α-CT or ELP renders them resistant to thrombin-releasing activity. Thrombin did not liberate any additional label from platelets which lost over 60% of serotonin during the preceding incubation with CLP. α-CT and ELP do not aggregate platelets either in the presence or absence of apyrase. CLP does aggregate platelets suspended in Tyrode buffer without apyrase but not in the presence of apyrase (100 mg/1). The action of α-CT, ELP and CLP on washed platelets induces a progressive prolongation of lag phase and a decrease in changes of light transmission during aggregation by thrombin. Similarly to α-CT-treated platelets, those subjected to CLP action aggregate in the presence of human fibrinogen.

It is concluded that: (1) neutral proteases possibly contribute to development of defects in platelet function in pathological states associated with liberation of leukocyte content into the circulation, (2) CLP similarly to a-CT, exposes fibrinogen receptors but in contrast to α-CT, CLP aggregates platelets and stimulates serotonin secretion.
The Behaviour of Various Platelet Function Tests During Long-Term Prostacyclin Infusion in Patients with Peripheral Vascular Disease
Authors: Sinzinger H , Horsch A K , Silberbauer K
Published: July 2018

In 20 patients with peripheral vascular disease treated with prostacyclin (5 ng/kg/min) we observed a significant activation of platelet function as measured by platelet proteins, ADP- induced aggregation platelet sensitivity and platelet count. Only the platelet survival was significantly prolonged by the treatment.
Indications of 5-Aminolevulinic Acid and Intraoperative MRI in Glioma Surgery: First Cases in Latin America in a Single Reference Center
Authors: Ramina Ricardo , Silva Júnior Erasmo , Constanzo Felipe , Coelho Neto Maurício
Published: July 2018

Introduction The improvement on the extent of resection (EOR) of gliomas with the combination of 5-aminolevulinic acid (5-ALA) and intraoperative magnetic resonance imaging (iMRI) has been demonstrated in previous studies. We present our results with the combined use of 5-ALA and (iMRI) in the surgery of glial lesions.

Methods A total of 64 cases of patients with intracranial gliomas who underwent image-guided surgery using 5-ALA with and without (iMRI) were reviewed. All patients underwent an early postoperative MRI to evaluate the EOR. Other intra-operative techniques (awake surgery, electrophysiological stimulation and monitoring) were also performed according to the location of the tumor.

Results A total of 18 tumors did not show intraoperative 5-ALA fluorescence (according to the World Health Organization [WHO] classification of tumors, 2 WHO-grade I, 14 WHO-grade II, 1 WHO-grade III and 1 WHO-grade IV), and 46 tumors showed intraoperative 5-ALA fluorescence (3 WHO-grade II, 3 WHO-grade III, 40 WHO-grade IV). In 28 of the 46 5-ALA positive cases, a safe 5-ALA free resection was achieved. In the 5-ALA negative cases, the (iMRI) findings guided the EOR, and complete resection was achieved in 11 cases. Complete resection was opted out in gliomas infiltrating eloquent areas.

Conclusions The combined use of 5-ALA and IMRI showed improved results in glioma surgery, offering the safest maximal EOR. In the 5-ALA positive cases (mostly high-grade), fluorescence was a more useful tool. In the 5- ALA negative cases (mostly low-grade), the (iMRI) was decisive to guide the EOR of the tumor.
Rückengesundheit beginnt im Kopf
Authors: Fleichaus Joachim
Published: July 2018

Das vorgestellte Kurskonzept zur Förderung der Rückengesundheit setzt auf eine Kombination von Training, Patienteninformation und
verhaltenstherapeutischen Elementen. Es bietet Therapeuten die Chance, sich mit Rückenschulkursen ein zweites Standbein für die Praxis aufzubauen. Die Kurse
können auf vereinfachtem Wege durch die Zentrale Prüfstelle Prävention zertifiziert werden.
Fallbeispiel Neurotraining – „Mir fehlt total die Idee“
Authors: Dassel Alexander , Horst Renata , Grell Niklas
Published: July 2018

Das Gewebe von Patienten in der Neuroreha hat oft schon über Jahre an Elastizität verloren. Erst wenn der Leidensdruck zu groß wird, sind Patienten bereit, daran zu arbeiten. Herr G. beispielsweise will wieder mit einer Tasche in der Hand durch Türen treten können. Anfangs fehlt ihm dazu die Idee. Sein Physiotherapeut unterstützt ihn, indem er sein Fasziengewebe beeinflusst.
Electromagnetic properties of the Great Pyramid: First multipole resonances and energy concentration
Authors: Balezin Mikhail , Baryshnikova Kseniia V. , Kapitanova Polina , Evlyukhin Andrey B.
Published: July 2018

Resonant response of the Great Pyramid interacting with external electromagnetic waves of the radio frequency range (the wavelength range is 200–600 m) is theoretically investigated. With the help of numerical simulations and multipole decomposition, it is found that spectra of the extinction and scattering cross sections include resonant features associated with excitation of the Pyramid's electromagnetic dipole and quadrupole moments. Electromagnetic field distributions inside the Pyramid at the resonant conditions are demonstrated and discussed for two cases, when the Pyramid is located in a homogeneous space or on a substrate. It is revealed that the Pyramid's chambers can collect and concentrate electromagnetic energy for the both surrounding conditions. In the case of the Pyramid on the substrate, at the shorter wavelengths, the electromagnetic energy accumulates in the chambers providing local spectral maxima for electric and magnetic fields. It is shown that basically the Pyramid scatters the electromagnetic waves and focuses them into the substrate region. The spectral dependence of the focusing effect is discussed.
Optimal control RF pulses for excitation and suppression of NMR signals in a conductive medium
Authors: Kharkov Boris , Strouk Leonard , Skinner Thomas E. , Jerschow Alexej
Published: July 2018

In this work, optimal control theory was used to design efficient excitation schemes in highly conductive materials, where both the radio frequency field strength and phase vary as a function of penetration depth. A pulse was designed to achieve phase alignment between signals at different depths within the conductor and thus to obtain higher signals from that region. In addition, an efficient suppression pulse was designed by insuring mutual suppression between the signals from various depths in the sample. The performance of the new approach was demonstrated experimentally for a bulk lithium sample for the excitation problem and for a biphasic metal/liquid sample for the selective suppression pulse.
Tunable direct-indirect band gaps of ZrSe2 nanoribbons
Authors: Li Shujing , Zhou Mei , Wang Xiaohui , Zheng Fawei , Zhang Ping
Published: July 2018

The atomic and electronic structures of armchair and zigzag ZrSe2 nanoribbons have been investigated systematically. Both the armchair and zigzag ZrSe2 nanoribbons are nonmagnetic semiconductors, while their bandgaps show quite different behaviors depending on the ribbon width. We find that all the zigzag ribbons possess direct energy gaps, which smoothly decline with the increasing ribbon width. On the other hand, energy gaps for the armchair ribbons change from direct gaps to indirect ones as the ribbon width increases and exhibit a width-dependent oscillation behavior. Moreover, the semiconducting behaviors and the bandgap types are robust, and they remain unchanged in bilayer and multilayer thin films with inter-layer interactions. These findings indicate that ZrSe2 nanoribbons are promising candidate materials for applications in nanoelectronic devices.
Magnetic diagnostic suite of the C-2W field-reversed configuration experiment
Authors: Roche T. , Thompson M. C. , Griswold M. , Knapp K. , Koop B. , Ottaviano A. , Tobin M. , Magee R. , Matsumoto T. ,   TAE Team
Published: July 2018

A fundamental component of any magnetically confined fusion experiment is a firm understanding of the magnetic field. The increased complexity of the C-2W machine warrants an equally enhanced diagnostic capability. C-2W is outfitted with over 700 magnetic field probes of various types. They are both internal and external to the vacuum vessel. Inside, a linear array of innovative in-vacuum annular flux loop/B-dot combination probes provide information about plasma shape, size, pressure, energy, temperature, and trapped flux when coupled with established theoretical interpretations. A linear array of B-dot probes complement the azimuthally averaged measurements. A Mirnov array of 64 3D probes, with both low and high frequency resolution, detail plasma motion and MHD modal content via singular value decomposition analysis. Internal Rogowski probes measure axial currents flowing in the plasma jet. Outside, every feed-through for an internal probe has an external axial field probe. There are many external loops that measure the plasma formation dynamics and the total external magnetic flux. The external measurements are primarily used to characterize eddy currents in the vessel during a plasma shot. Details of these probes and the data derived from their signals are described.
Deformation of contacting interface between polymer hydrogel and silica sphere studied by resonance shear measurement
Authors: Mizukami Masashi , Ren Huai-Yin , Furukawa Hidemitsu , Kurihara Kazue
Published: July 2018

The deformation of the interfaces between a soft material and hard material in contact plays an important role in the friction and lubrication between them. We recently reported that the elastic property of the contact interface dominated the friction of the interface between a flat polymer hydrogel [double network (DN) gel of 2-acrylamide-2-methylpropanesulfonic acid and N,N-dimethylacrylamide] and a silica sphere [Ren et al., Soft Matter 11, 6192–6200 (2015)]. In this study, in order to quantitatively describe the dependence of the elastic response on the geometrical parameters of the deformed interfaces, we employed the resonance shear measurement (RSM) and investigated the deformation of the interfaces between a flat DN gel and silica spheres by varying the curvature radius (R = 18.3, 13.8, 9.2, 6.9 mm). Resonance curves were analyzed using a mechanical model consisting of the elastic (k2) and viscous (b2) parameters of the contact interface. The obtained elastic parameter (k2) increases at higher loads and for smaller silica spheres, while the viscous parameter (b2) was negligibly low for all the conditions. The relations between the elastic parameter (k2), geometric parameters of the deformed contact interface, and the applied normal load were investigated. The elastic parameter (k2) was found to be proportional to the arc length (arc) (radius of contact area, r), i.e., k2 ∝ arc or k2 ∝ r. We introduced the term “elastic modulus of the contact interface, Econtact” as a proportionality constant to describe the elastic parameter of the deformed interfaces (k2): k2 (N/m) = arc (m) × Econtact (Pa). Thus, the friction (f) between the DN gel and the silica sphere can be described by the following equation: f = felastic = arc (m) × Econtact (N/m2) × Δx (m) (Δx: shear deformation of the contact interface between the DN gel and silica sphere). The Econtact value determined from the slope k2 vs arc was 493 ± 18 kPa. The RSM measurement and the analysis presented here can be a unique method for characterizing the specific properties of the deformed interfaces between soft and hard materials.
Protein encapsulation via polyelectrolyte complex coacervation: Protection against protein denaturation
Authors: Zhao Mengmeng , Zacharia Nicole S.
Published: July 2018

Complex coacervation can be used as a route to compartmentalize a variety of solutes such as organic small molecules, inorganic nanoparticles, and proteins within microscale coacervate droplets. To obtain insight into the accumulation of proteins within complex coacervate phases, the encapsulation of Bovine Serum Albumin (BSA) within complex coacervates containing cationic polyelectrolyte poly(allylamine hydrochloride) (PAH) and anionic polyelectrolyte poly(acrylic aid) (PAA) was investigated as a function of mixing sequence, total polyelectrolyte concentration, BSA overall concentration, and the mixing molar ratio of PAA/PAH. Mixing BSA having a negative net charge with the polycation PAH before coacervation, increasing the total polyelectrolyte concentration and PAA/PAH molar ratio, or decreasing the BSA overall concentration led to more efficient protein encapsulation. Preservation of the secondary structure of BSA during the complex coacervation process was confirmed using circular dichroism spectroscopy. Our study shows that PAA-PAH coacervates can serve as a protective system against the denaturation of BSA when exposed to extremes of pH, high temperatures, as well as in solution of urea. Additionally, it was found that by encapsulation of proteins within coacervates via complex coacervation, the complexation between proteins and heavy metal can be efficiently inhibited. Protection of BSA against severe environmental conditions via encapsulation within polyelectrolyte coacervates provides new insights and methods to issues of maintaining stability and function of proteins.
Establishment success and persistence of threatened plant translocations in south west Western Australia: an experimental approach
Authors: Dillon Rebecca , Monks Leonie , Coates David
Published: July 2018

Establishment of viable threatened plant populations through translocations presents significant practical and logistical challenges. To address these challenges there is a need for experimental studies that inform refinement of translocation methodologies to optimise seedling survival during the establishment phase. In the present study we investigated the effect of three post planting techniques on the survival and growth of six translocated threatened plant species in south-west Western Australia over a 10-year period. Planted seedlings received summer watering for the first year, mulch or protection from vertebrate herbivores. Survival of seedlings was significantly enhanced in both watering and fencing treatments, but was not positively influenced by the mulch treatment. Plant growth was also significantly improved by the fencing treatment. Results showed that both fencing and supplementary summer watering were two very effective approaches for enhancing seedling establishment and plant persistence. We emphasise the value of integrating an experimental approach involving long-term monitoring into threatened plant species translocations and recovery programs for improving plant translocation success.