bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution Of Platelets In PTFE Bypass Grafts
Authors: Christenson J T , Megerman J , Hanel K C , L’Italien G J , Abbott W M , Strauss H W
Published: July 2018

Autologous platelets labeled with Indium-lll-oxine were used to examine the thrombotic process by which small diameter bypass grafts often fail. PTFE grafts were inserted into the carotid and femoral arteries of dogs, and labeled platelets were injected. Thirteen 6 cm grafts (Group I) were harvested after 3 hrs as follows: after systemic heparinization, the graft and adjacent arterial segments were perfuse-fixed in situ, cut open longitudinally, rinsed gently in saline and counted in a well counter. The flattened specimen was then placed inside an x-ray cassette for 24-48 hrs, depending on measured total activity. Fifteen 4 cm grafts (Group II) were similarly harvested, but 4 days later. All grafts included herein were patent. The autoradiograph was developed in an automatic processor and subjected to densitometry to quantitate platelet deposition. Each graft image was divided into 3 longitudinal segments.

The average density in the proximal and distal artery was zero. Significant differences (p<.01) were measured between segments within each group, and between the 2 groups. Deposition in the distal segment, compared to that in the proximal segment, was 65% greater in group II than in group I. With time, therefore, platelets were preferentially deposited toward the distal anastomosis. The tendency to form occluding thrombus is thus non-uniform along the length of PTFE bypass grafts. No dependence of platelet deposition on flow was observed; their distribution appears to be independent of flows ≥ 60 ml/min. Efforts to reduce thrombosis in current PTFE bypass grafts should focus on the influence of the distal anastomosis on blood-surface interactions within the graft.
The Heparin-Glotar Surface; Mdde Of Action And Practical Application
Authors: Olsson P , Larsson R , Lins L-E , Nilsson E
Published: July 2018

A heparinized surface with non-thrombogenic characteristics was prepared by stabilization of an ionic heparinamine complex with glutardialdehyde. The process can be applied to a large variety of materials.

The coating makes the surface platelet canpatible because np fibrinogen is adsorbed. The interaction of the surface with plasma coagulation system is based upon its ability to adsorb active coagulation enzymes (thrombin) and to promote inhibition of the adsorbed enzyme in the presence of circulating anti thrombin III. The sequence involving enzyme adsorbaticn and subsequent inhibition is regenerative. Investigations on blood vessels have revealed that the intact endotheliim exerts a similar mode of action with regard to inhibition of coagulation enzymes.

When the heparin in the surface coating is substituted for glucosaminoglycans with less anticoagulant activity than heparin, the created surfaces is still platelet compatible and maintains the ability to adsorb enzyme, but loses the ability to generate inhibition of the adsorbed enzymes. Such surfaces are highly thrcmbogenic.

The heparin surfaces have been tested experimentally for various applications. A heparin coated intravascular pO2 sensor was used for accurate measurements without recalibrations for several days. A non-heparinized electrode deteriorated within hours. Hemodialysis was performed on non-heparinized dogs using surface-heparinized hemodialysis set.
The Effect Of Purification On The Quarternary Structure Of Factor VIII-VWF
Authors: van Mourik J A , Over J , Hellings J A
Published: July 2018

As an index of denaturation, the ratio of Factor VIII coagulant antigen (VIII:CAg) to Factor VIII coagulant activity (VIII:C) as measured in plasma, cryoprecipitate and cryosupernatant plasma from fresh and stored blood and in several concentrates. The ratio of VIII: CAg to VIII: C was close to unity for both cryoprecipitate and factor VIII concentrates, suggesting that VIII: CAg is lost concurrently with VIII: C during cryoprecipitation and further fractionation. Together with VIII:C, a substantial amount of VIII: CAg was recovered in the cryosupernatant. Storage of blood for 24h before processing resulted in a 30% loss of VIII: C from the separated plasma, but the level of VIII: CAg was not affected. In cryoprecipitate, prepared from this plasma, VIII: C and VIII: CAg were both 30% lower than in that prepared from fresh plasma. A corresponding rise of VIII: CAg, but not of VIII: C, in the cryosupernatant was found.

Gel chromatographic analysis revealed that the rise of VIII: CAg in cryosupernatant, prepared from stored blood, was due to an increased amount of VIII: CAg that eluted after the void volume which was no longer associated with VIIIR: Ag. Such an increase in dissociated VIII: CAg was not detected in the plasma derived from stored blood prior to cryoprecipitation.

It is concluded that during storage of blood molecular changes are induced in the factor VIII complex, which makes the complex more liable to dissociation during the subsequent cryoprecipitation procedure. Similarly, losses of VIII: C during further purification of the Factor VIII complex should be interpreted in terms of dissociation of the VIII: C constituent unit and not merely considered as a result of denaturation of VIII: C present in the native complex.
An Apparent Effect Of Size Distribution Of FVIIIR: Ag Multimers On Immunoradiometric Assays
Authors: Lamb M A , Reisner H M , Cooper H A , Wagner R H
Published: July 2018

Immunoradiometric assays (IRMA) of FVIIIR: Ag from normal and certain variant VWD plasmas have suggested possible antigenic differences in the molecules. Studies reported thus far have used antibody specific for normal FVIIIR: Ag. We have further studied this question of antigenic differences using 2 populations of antibody isolated from an antisera prepared against highly purified human FVIII. Isolated IgG was labeled with [125-I]. The population of labeled IgG “specific” for variant FVIIIR: Ag was separated by immune complex formation with a VWD plasma previously shown, by 2% agarose crossed immunoelectrophoresis, to contain only the lower molecular weight multimers of FVIIIR: Ag. The “specific” labeled IgG was obtained by low pH dissociation and subsequent G-200 chromatography. [125-I] IgG “specific” for normal FVIIIR: Ag was similarly obtained after immune complex formation with pooled normal human plasma. Liquid phase IRMAs were performed using differential precipitation with ammonium sulfate or PEG to separate antigen-antibody complexes from free antibody. Using antibody “specific” for normal FVIIIR: Ag, a lack of parallelism was noted in the dose-response curves of variant plasmas as well as a decrease in maximum antibody bound, as compared to normal. Interestingly, when this antibody was absorbed with the variant VWD plasma and the remaining antibody used in IRMAs, none was bound by either variant or normal plasma.

Using antibody “specific” for variant FVIIIR: Ag, a similar lack of parallelism in dose-response curves and a decrease in maximum antibody bound were observed. Therefore rather than antigenic differences as previously implied, these results suggest that the discrepancies noted in IRMAs of variant and normal plasmas are a function of the size of the FVIIIR: Ag multimers.
Hemagglutination Assay For Determination Of Human Factor VIII:C
Authors: Kang E P , DeSouza D I , Fitzpatrick M J , O’Neill S P
Published: July 2018

New methods for the determination of human factor VIII clotting protein (F. VIII:C) have been developed utilizing hemagglutination technique without using any other coagulation proteins in the assay. A 50% ammonium sulphate precipitate of the plasma from a hemophilic patient containing high titer of F. VIII:C inhibitor was purified on an affinity column of sepharose 4B covalently linked to F.VIII:C by CNBr. The 2.8 M MgCl2 eluted protein, after dialysis against 0.1 M phosphate buffered saline (pH 7.4), was coupled on either fresh or stabilized human erythrocytes by using either chromic acid or glutaraldehyde as the coupling agent. Serial dilutions of human plasma or F. VIII concentrate were added to the anti-F.VIII:C coated red cell suspension on a microtiter plate. For the stabilized cells, the plate was incubated on a vibration-free surface at room temperature. The results were read after two hours. For the fresh cells, the plate was incubated at room temperature for 30 minutes and was centrifuged at 300 Xg for ½ minute. It was then placed on a tilted platform at a 600 angle. The results were read after 10 minutes. By these methods, it is possible to determine the detectable level of F.VIII:C in plasma and the F.VIII:C concentration in cryoprecipitates and F.VIII concentrates.
Tissue Extract Induced Platelet Stimulation, Primary Hemostasis And Thrombosis
Authors: Breddin K , Bender N , Kirchmaier M C
Published: July 2018

Subcutaneous tissue, blood vessels, muscle and different organs of different species (Human, pig, dog and rat), contain an activity which within seconds transformes disk shaped platelets into sphered forms with pseudopodes (stimulated platelets) in freshly drawn citrated blood or whole blood.

Morphologic platelet changes were investigated using interference contrast microscopy. Retention was measured with a modified glass bead filter.

Platelet stimulation was accompanied in vitro by enhanced adhesion and enhanced aggregability. The tissue extracts did not induce platelet aggregation. The active fractions were free of thromboplastic activity. In vivo reversible platelet stimulation could be demonstrated in rat mesenteric vessels. Even in the presence of the platelet stimulating tissue extracts plgtelets retained their disklike shape if incubated at 37°C.

It is likely that local release of this Hemostasis Activating Factor (HAF) from damaged cells intensely and rapidly enhances primary hemostasis in the presence of von Willebrand factor. Atheromatous material is rich in platelet stimulating activity. The role of local platelet stimulation at defective endothelial cells, vessel wall ruptures and atheromatous plaques as a trigger for thrombus formation has to be established.
Concentrations Of Several Hormons In A Factor XIII Preparation Of Placental Origin
Authors: Krämer W , Mittelstaedt G H V , Schmidt R , Heene D L
Published: July 2018

A 13 year old male patient suffering from an inborn factor XIII deficiency was treated by a factor XIII concentrate to cure a pseudotumor at the leg. Under treatment the patient showed clinical symptoms which were regarded as notyet observed hormonal side effects. The used preparation was made of human placenta. It seemed to be instructive to analyse in this concentrate the amount of several placental hormons.

Three randomised charges of this factor XIII preparation were investigated for the hormonic activity of LH, prolactin, FSH, cortisol, HPL, free oestriol, total oestriol and testosteron. All determinations were carried out by RIA. Elevated concentrations for testosteron and up to the reach of the second period of pregnancy for LH and total oestriol were found.

It is necessary to pay attention to hormonal side effects in treating patients with factor XIII preparations made of placental origin.
Involvement Of Factor VII In Intrinsic Coagulation Pathway: Synthetic Substrate Assay For Coagulation Factor Activities In Plasma
Authors: Aiyappa P Ashok
Published: July 2018

A spectrophotometric assay system to measure the coagulation factor activities in plasma is developed. The reagent system contains a soluble surface activator to initiate the contact phase activation, phospholipids and Ca++. The plasma is diluted with the reagent in a ratio of 1:100 and incubated at 37°C for 5 minutes. Subsequently, the thrombin generated is measured by the addition of a synthetic tripeptide chromogenic substrate (Sarc-pro-Arg- pNA) relatively specific for thrombin. This assay system is sensitive to the deficiency of all the clotting factors (XII, Prekallikrein, XI, IX, VIII, V, X and Prothrombin) conventionally measured by the APTT test system. However, it differs from the clotting time assay in that it is sensitive to deficiency of Factor VII as well. The adsorbed plasma, when mixed with the Factor VII deficient plasma, failed to correct the Factor VII deficiency, where as the Serum reagent corrected the Factor VII deficiency. Addition of purified Factor VII to the Factor VII deficient plasma resulted in the generation of thrombin, suggesting that Factor VII is obligatory for thrombin generation under the assay conditions. Thus the existance of an Intrinsic Coagulation Pathway involving Factor VII is indicated. This assay system should prove to be useful for studying the interrelationships between various coagulation pathways.
A New Factor Control Plasma For Establishing Calibration Curves For Factor-Assay In Extrinsic And Intrinsic System
Authors: Spaethe R , Lampart A , Naumann M , Strauss J
Published: July 2018

We present a lyophilised human plasma which is optimal for calibration curves and factor control in extrinsic as well as in intrinsic system. Comparative assays were carried out between factor control plasma and a fresh plasma pool which was frozen at -70°C from 15 normal young men. The fresh plasma pool and the factor control plasmas for the calibration curves were diluted with Owren’s veronal buffer pH 7,35 in a geometric sequence. All deficiency plasmas (American Dade, Division of American Hospital Supply Corporation) were used according to the instructions of the manufacturer. All assays were carried out by two independant investigators.

For the extrinsic system Thromboplastin C and FS (American Dade) were used. With this thromboplastin the callibration curves for the fresh plasma pool and the factor control plasma showed an identical course when plotted semilogarithmically. The calibration curves for the factors II, V, VII, and X showed a good correlation to normal plasma pool.

For the intrinsic system the PTT-reagent Actin (American Dade) was used. The measuring times for the calibration curves of the factor control plasma are slightly longer than of the fresh plasma pool.

When factors determined in factor control plasmas are read from the fresh plasma calibration curves, the range of normal values is from 90 to 105% for the factors in extrinsic system and from 80 to 105% in intrinsic system. According to these assessments, the factor control plasma seems to be appropriate for establishing calibration curves for factor assays as well as for calibration of thromboplastin time. This is a contribution to further standardization of coagulation assays.
Studies On The Catabolism And Distribution Of Fibrinogen In Rats. Application Of The IodogenR Labelling Technique
Authors: Nieuwenhuizen W , Emeis J J , Vermond A , Kurver P , Heide D V D
Published: July 2018

Catabolism and body distribution of fibrinogen was assessed in an homologous system. Rat fibrinogen was labelled with recently published iodogenR labelling technique: 125I was incorporated in fibrinogen at a ratio 0.5:1. Radioclottability appeared to be greater than 95%. The preparation was biologically screened in a rat for 48 hours. With the biologically screened fibrinogen, catabolism and body distribution parameters in the rat were determined by following the blood radioactivity versus time. Data were analyzed using a two-compartment mathematical model described by the function x (t) = C1e-a1t + C2 e-a2t.

From the constants C1, C2, a1 and a2 were calculated: transcapillary efflux rate constant = 0.056 ± 0.014 h-1 transcapillary reflux rate constant = 0.22 ± 0.06 h-1 fractional catabolic rate constant = 0.039 ± 0.013 h-1 intravascular fraction of fibrinogen pool = 77 ± 3% extravascular fraction of fibrinogen pool = 23 T 3% biological half-life time = 23 ± 1 h
Stabilized Fibrin Urea-Dispersion In Normal Plasma And Serum
Authors: de Cataldo F , Baudo F , Mussini E , Redaelli R
Published: July 2018

Clots from human normal native platelet-poor-plasma are dispersed by the addition of urea, final concentration 2.5 M. Cross-linked fibrin, preincubated in undiluted plasma and serum, is also dispersed by urea. Clot-dispersion is not inhibited by EACA, added to plasma prior to clotting or preincubation, at the final concentration of 5×10-2 M which inhibits streptokinase-plasminogen activation in the same plasma sample.

Characterization of this activity has been carried out by the following procedures:
1. Ammonium-suiphate-fractionation. The activity is recovered in the material precipitated at 13-17% concentration. 2. Sephadex chromatography (G 200, 150, 100). The activity is recovered in the protein material with 150.000-300.000 daltons, eluated at pH 7.2.
3. Dialysis of the ammonium-sulphate-precipitate against a solution buffered with TRIS or phosphate 0.1 M, pH range b-8.5 at 4°C. The activity is recovered in the gelatinous material selectively precipitated at pH 7.2.
4. Standard preparative electrophocusing on Sephadex plate
(Ultrodex LKB). The activity is recovered only in some of the thirty protein-fractions.

EACA does not inhibit the fibrin dispersing activity of these different materials.

These results indicate the presence in normal plasma and serum of a fibrin-dispersing activity different from plasminogen.
A Clinical Comparison Of Chromogenic, Fluorometric, And Natural (Fibrinogen) Substrate Assays For Determination Of Antithrombin-III
Authors: Bick R L , McClain B J
Published: July 2018

Antithrombin-III (AT-III) is a key modulator of hemostas- sis; decreases are thought to be associated with thrombosis, and the degree of decrease is thought to be indicative of severity of an intravascular clotting process. The popularity of AT-III determinations has been associated with the development of several different methodologies. To assess the clinical applicability of these different methodologies, chromogenic (Abbott), fluorometric (Dade), and fibrinogen (Cutter) substrate assays were performed on 84 individuals with disseminated intravascular coagulation (DIC) or intravascular thrombosis (DVT, PE). Severity of the intravascular coagulation or thrombosis was clinically graded as 1 through 6 by one observer; thromboscintograms were used to confirm the clinical impression: single calf thrombosis = 1, DIC = 6. Multiple linear regression analyses were performed to correlate assay resus with clinical severity of disease. All patients were expected to have abnormally low AT-III levels because of documented intravascular thromboses. However, three were normal by the fluorometric assay, 26 were normal by the chromogenic assay, and 12 were normal by the fibrinogen-substrate assay. When comparing assays the correlations were as follows: Cutter vs. Dade: r=0.70; Cutter vs. Abbott: r=0.70; Dade vs. Abbott: r=0.64. When correlating the assay method with severity of intravascular coagulationAihrombosis the following was found: Cutter: r=0.44, Dade: r=0.76, and Abbott: r=0.43. The means and standard deviations for the entire population are as follows: Cutter = 79.8 ∓ 29.2, Dade = 79.0 ∓ 19.8, and Abbott = 102.0 ∓ 30.2. Based upon this study the most clinically applicable and useful assay appears to be the fluorometric method (Dade). Because of diagnostic accuracy, automation, and ease of performing the assay this is the recommended method and, therefore has been the assay adopted in our laboratory for routine clinical use.
Antithrombin III Activity Levels In Serum: Results Of A Large Survey Study Using A New Method Of Sample Preparation
Authors: Gray A , Uhlmeyer K , LaBonte R , Bailey L
Published: July 2018

The determination of Antithrombin III (AT III) levels in serum is of major interest because the serum AT III level will reflect both the level of AT III in the circulation (plasma AT III) and the level of procoagulant factors in the circulation (which consume the AT III during serum formation in vitro). Serum samples are also more readily available for testing in reference laboratories who normally receive very few citrated plasma samples. A collaborative study was performed to test AT III levels on all serum samples sent in to the Bio-Diagnostics Medical Laboratory for chemistry panel testing during a one month period.

It has been recognized that the level of prothrombin consumption during serum formation will vary widely depending on the sample handling conditions. Only a small amount of thrombin generation is required for complete defibrination of a blood sample. Some serum samples collected in glass without an anticoagulant still had normal plasma levels of prothrombin and AT III. This may indicate early removal of platelets by centrifugation, low levels of contact factors or rapid anticoagulation kinetics. A new method was devised to standardize the complete activation (and thus AT III consumption) of samples received from approximately 800 offices and clinics collecting and mailing the samples under various conditions. To 100 ul sample serum was added 10 ul of commercial thromboplastin/calcium ion solution to activate the sample extrinsically. After at least five minutes, the samples were assayed for their AT III activity using the Quanticheck AT III assay on an Abbott VP. A total of 5800 samples were assayed with a mean value of 83 ± 1 (2 S.D.). There were 132 samples outside of the normal range of 74 ± 20 % AT III (determined on 99 normal adults).
Antithrombin-III Deficiency Causing Deep Vein Thrombosis And Pulmonary Embolism In A Young Male
Authors: Genth K , Schaefer J , Frank J , Krämer W , Weinei B , Heene D
Published: July 2018

A 34 year old male was admitted to the hospital with typical clinical symptoms of acute pulmonary embolism caused by deep vein thrombosis in the upper leg detected by phlebography. Pulmonary embolism was verified by the lung-perfusion-scintigram. The patient developed an infarct pneumonia with hemoptoe. Episodic thromboembolic phenomena occurred due to antithrombin-III deficiency (AT-III). The method, using homogenic substrates exhibited low AT-III activity of 8.6 IU/ml(25°C) due to a familiar AT-III deficit. Fiberoptic pulmonary catheter was placed into the pulmonary artery to measure pulmonary artery pressure (PAP, PCP), right ventricular pressure (RVP) and to determine cardiac output (CO) using the dye dilution technique. Heart rate (HR), central venous pressure (CVP) and aortic pressure (AOP) were recorded continuously. Patient received immediately fibrinolytic therapy, initiated by an initial dose of streptokinase (SK)(250 000 IU/20 min.), followed by a maintenance dose (100 000 IU/h), lasting 3 days. M-mode echocardiography detected before SK a moderate enlarged right ventricle and a small left ventricle, indicating a low output. After SK these values were improved. In conclusion, this case demonstrated a serious thromboembolic disorder, related to AT-III deficit. SK-therapy improved the hemodynamic situation.
Inherited Deficiency Of Antithrombin III In Two Italian Families. Different Behaviour After Long-Term Anticoagulant Treatment
Authors: Manotti C , Pini M , Poti R , Quintavalia R
Published: July 2018

An inherited deficiency of antithrombin III (AT III), measured with four different, functional and immunological, methods, was found in 8 out of 11 examined members and in 3 out of 11 examined members of two Italian families (D.M. and A. families). Biological activity, measured with Abildgard’s clotting assay and with an amidolytic method, ranged between 17 and 75%. Cross immunoelectrophoresis, with or without heparin, performed in the two propositi and in 1; other relatives, showed a normal pattern of migration.

A different behaviour of AT III after anticoagulation with acenocoumarin was seen in two long-term treated subjects. The proposita of the D.M. family, who had a history of recurrent thrombotic accidents, did not show any increase of AT III levels, measured in the first two weeks and after 6 and 12 months of therapy. A significant (about 50%) increase both with the functional and immunological methods was on the contrary observed in the propositus of A. family, who had undergone surgery because of mesenteric vein thrombosis. Until now both patients have been free of thrombotic recurrences.

Our findings confirm previous reports of variable effects of oral anticoagulants on AT III levels in subjects with congenital deficiency.
Application Of Enzyme Kinetic Analysis In The Development Of An Automated Ant I Thrombin III Assay
Authors: Perry J F , Wehrly J A , Coleman P L
Published: July 2018

The need for adherence to basic enzyme kinetics principles in the measurement of coagulation enzymes with synthetic substrates has recently been addressed by the ICTH Subcommittee on Synthetic Substrates. We describe an assay for anti thrombin III (AT III) that was developed through characterization of the system kinetic parameters and their subsequent cooptimization. A large field of thrombin substrates and reaction buffers was surveyed for combinations yielding lowest Km values. Those selected were further analyzed by multi-variate response surface analysis to maximize reaction kcat while simultaneously minimizing Km. The resultant optimized system provides a kinetically valid means to measure thrombin and forms the basis for the AT III determination. The addition of the AT III activator heparin leads to the final optimized assay design. The analytical performance of the automated method evaluated through studies on precision, linearity, interference and correlation, was acceptable. The linear range of the method is 0-150% Normal Human Plasma (NHP). Day-today precision at the medical decision level of 80% NHP shows a CV of 3%.
Platelet Factor 4 (PF4) And Protamine Sulfate (PS) Neutralization Of Heparin Fractionated According To Charge Density
Authors: Poon M-C , Hurst R E
Published: July 2018

Both PF4 and PS have been postulated to neutralize heparin by electrostatic complex formation. The present study examined the role of charge density (Z) of the heparin in neutralization reactions with PF4 and PS. Fractions varying systematically in charge density were isolated from 3 hog mucosal (HM) heparins (2 decolorized and 1 undecolorized) using 2 phase sequential extraction system. Fractions were similarly isolated from a decolorized beef lung (BL) heparin. Thrombin inhibition (ThI) assays were performed in the absence and presence of a constant amount of PF4 or PS for each fraction and for a series of dilutions of a standard heparin. The potencies of fractionated heparins varied systematically in a non-linear manner with Z2. However, in all heparins studied, potency curves generated in the presence of PF4 and PS paralleled each other closely. With the 2 decolorized heparins, these curves also closely paralleled the potency curves generated in the ThI assay in the absence of PF4 or PS (ThI-buffer curves), but for the undecolorized heparin, the ThI-buffer curve was distinctly of steeper slope with greater potency. In contrast, with BL heparin , the ThI-buffer curve was of shallower slope and of lower potency.

The parallel behavior of PF4 and PS curves supports a similarity in the mechanism of neutralization. The potency of heparin fractions is related to their charge density. With decolorized HM heparins, PF4 and PS do not selectively neutralize a subfraction with different potency, but with the undecolorized heparin, PF4 and PS is somewhat selective towards neutralizing more potent heparin species. In contrast, with BL heparin, a less active heparin species is apparently preferentially inactivated by PF4 and PS, and moreover, the activity is less subject to neutralization.
Behaviour Of Exogenous Heparin In Patients With Nephrotic Syndrome
Authors: Fischer A M , Guillot M , Girot R , Léon M , Triadou P , Dautzenberg M D , Jacques C , Josso F
Published: July 2018

Behaviour of exogenous heparin was studied in 35 subjects after intravenous injection of 50 u/kg heparin : 10 healthy control adults, 8 control children with normal hemostatic system, 17 children with nephrotic syndrome without renal insufficiency. Blood samples were collected before injection and 15 min, 30 min, 60 min and 120 min later, for the following tests : APTT, thrombin time, automatised heparin assay using a chromogenic substrate (S-2238). Heparin behaviour was assessed by two criteria : recovery (plasma heparin level) 15 min after the injection ; halflife of recovered heparin. Results were compared with the following parameters : WBC and platelet count ; serum albumin and lipids ; plasma antithrombin III, α2 macroglobulin and fibrinogen ; histological findings when available

In nephrotic children, mean heparin recovery was lower than in the control groups, very poor or even negligible in 9/17 cases. Heparin halflife was close to 37 min in most patients, shorter than in healthy controls (mean : 46 min), and dramatically decreased in 4 cases.

No significant correlation was observed between the observed heparin behaviour and the considered parameters ; sensitivity to heparin was notably unrelated to plasma antithrombin III level. Insensitivity was observed in three patients with amyloidosis.
Local Delivery of Platelets with Encapsulated lloprost to Balloon Injured Pig Carotid Arteries: Effect on Platelet Deposition and Neointima Formation
Authors: Banning Adrian , Brewer Lesley , Wendt Maria , Groves Peter H , Cheadle Hilary , Penny William J , Crawford Neville
Published: July 2018

Local delivery of a drug to the arterial wall during angioplasty is an approach which might reduce the incidence of occlusive events such as thrombosis and restenosis, without the risk of systemic side effects. By exploiting their natural primary haemostatic properties, platelets, with encapsulated drugs, can be targeted to a vessel wall injury site and act as a depot for sustained release. The platelet plasma membrane can be reversibly permeabilised by high voltage, short duration electrical pulses (electroporation). Drugs will diffuse into porated platelets and become trapped on resealing. We have studied the effects of autologous platelets, electroloaded with the stable prostacyclin analogue, iloprost, on platelet deposition and neointima formation in a pig carotid angioplasty model. Iloprost loaded or control platelets were delivered locally and immediately to the balloon injured site using a double balloon delivery catheter. Acute platelet deposition was measured using 111-Indium, and neointima formation at 21 days post angioplasty was assessed by morphometric analysis. In pigs treated with iloprost loaded platelets, platelet deposition on the artery at 2 hours post injury was dramatically reduced (to approximately monolayer coverage), when compared with arteries from pigs treated with control platelets. In pigs with deeply injured arteries, i.e. with extensively ruptured internal elastic lamina (IEL), platelet deposition was reduced by 88% compared with control arteries (118 ± 20 X 106/cm vs. 14 ± 2 X 106/cm, means ± SE, 2P <0.001). In minimally injured arteries (IEL intact) a 65% reduction in platelet deposition was observed (55 ± 24 X 106/cm vs. 19 ± 3X 106/cm, 2P <0.002). A high concentration of free iloprost, delivered to the angioplasty site, with control platelets, had far less effect on platelet deposition, substantiating the advantage of platelet encapsulation. At 21 days post injury, morphometry of the carotid arteries after treatment with iloprost loaded platelets showed significant reductions in intimal area and intimal/medial ratios in minimally injured vessels (P <0.05) as compared with vessels from pigs treated with control platelets. With deeply injured vessels, the mean differences (control vs. treated) for the same morphometric parameters were not significant.

This novel approach of electro-encapsulating drugs within autologous platelets, and using them as highly biocompatible and biodegradable drug targeting vehicles might, with the appropriate choice of encapsulated agent, have potential for reducing the incidence of occlusion after angioplasty and thrombolysis procedures.
A Common Thrombomodulin Amino Acid Dimorphism Is Associated with Myocardial Infarction
Authors: Norlund Lena , Holm Johan , Zöller Bengt , Öhlin Ann-Kristin
Published: July 2018

Endothelial dysfunction and haemostatic imbalance are believed to be important aetiological factors in the development of acute coronary syndromes. Thrombomodulin (TM) is an integral membrane protein crucial for normal endothelial function and activation of the protein C anticoagulant pathway. We have investigated the importance of a common C/T dimorphism in the TM gene (nucleotide 1418) for development of premature myocardial infarction (MI). The C/T dimorphism predicts an Ala455 to Val replacement in the sixth EGF-like domain of TM. The dimorphism was investigated in 97 MI survivors and 159 healthy controls. The C allele was significantly more frequent among patients than controls (p = 0.035). The allele frequency for the C allele was 0.82 in the patients and 0.72 in the control group. The plasma concentration of TM was investigated among healthy controls but was not related to the C/T dimorphism. In conclusion, the association of the C allele with premature MI, suggests that the TM gene and the C/T dimorphism may be aetiological factors involved in the pathogenesis of MI. Possibly, the Ala455 to Val replacement may affect the function of the TM molecule and the activation of the protein C anticoagulant pathway.
Clinical Features in 36 Patients Homozygous for the ARG 506 → GLN Factor V Mutation
Authors: Emmerich Joseph , Alhenc-Gelas Martine , Aillaud Marie-Françoise , Juhan-Vague Irène , Jude Brigitte , Garcin Jean-Marie , Dreyfus Marie , de Moerloose Philippe , Le Querrec Agnès , Priollet Pascal , Berruyer Micheline , Vallantin Xavier , Wolf Martine , Aiach Martine , Fiessinger Jean-Noël
Published: July 2018

We analyzed the clinical features of 36 patients homozygous for the Arg 506 to Gin factor V mutation and found a circumstantial event at risk for thrombosis in 29 of the 31 patients with thrombosis. The most frequent predisposing factors were the post-partum period and the use of oral contraceptives in women, and surgery in both sexes. Venous thrombosis recurred in 48% of the patients. One patient had a myocardial infarction at age 33 years, and also had an antiphospholipid syndrome. Homozygous Gin 506 mutation leads to far less severe thrombotic complications than homozygous protein C and protein S deficiencies and does not seem to predispose patients to arterial thrombosis.
Purpura Fulminans Induced by Disseminated Intravascular Coagulation following Infection in 2 Unrelated Children with Double Heterozygosity for Factor V Leiden and Protein S Deficiency
Authors: Inbal Aida , Kenet Gilly , Zivelin Ariella , Yermiyahu Tikva , Bronstein Tamar , Sheinfeld Tomy , Tamari Hana , Gitel Sanford , Eshel Gill , Duchemin Jerome , Aiach Martine , Seligsohn Uri
Published: July 2018

Purpura fulminans is associated with homozygous protein C and homozygous protein S deficiency or may follow bacterial or viral infections. We present 2 children from 2 unrelated Arab families with purpura fulminans who were double heterozygotes for factor V Leiden inherited from their fathers and protein S deficiency inherited from their mothers. No previous thrombotic events have occured in either patient or their respective family members. In one patient sepsis accompanied by disseminated intravascular coagulation appeared to be the trigger of purpura fulminans. In the other patient varicella infection preceded purpura fulminans and was also associated with disseminated intravascular coagulation. This report emphasizes the need for evaluation of hereditary defects in the inhibitory mechanisms of blood coagulation in patients with purpura fulminans at any age.
SQ 22536, an Adenylate-Cyclase Inhibitor, Prevents the Antiplatelet Effect of Dazoxiben, a Thromboxane-Synthetase Inhibitor
Authors: Bertelé Vittorio , Falanga Anna , Tomasiak Marian , Cerletti Chiara , Gaetano Giovanni de
Published: July 2018

This study shows that dazoxiben, a selective inhibitor of thromboxane A2-synthetase in human platelets, inhibited arachidonic acid-induced platelet aggregation in platelet-rich plasma samples from four out of 16 healthy volunteers. In these four “responder” samples, the anti-aggregating effect of dazoxiben was prevented by the compound SQ 22536, a 9-substituted adenine analogue, endowed with an inhibitory activity on adenylate-cyclase. The compound SQ 22536 also counteracted the antiaggregating effect of prostaglandin D2, a known activator of platelet adenylate-cyclase. When platelet thromboxane A2-syn- thetase was blocked by dazoxiben, a marked increase of prostaglandin D2 was concomitantly observed both in “responder” and “non responder” samples. The compound SQ 22536 blunted the increase in platelet cAMP caused by either dazoxiben and sodium arachidonate or prostaglandin D2. It is suggested that the antiaggregating effect of dazoxiben is mediated by newly synthesized prostaglandin D2. The latter acts by stimulating adenylate-cyclase and increasing cAMP levels. The compound SQ 22536 prevents both phenomena. In “non responder” samples some factors - still to be defined - might counteract similarly to the compound SQ 22536 the antiaggregating activity of PGD2.
Standardization of Factor VIII – III. Establishment of a Stable Reference Plasma for Factor VIII-Related Activities
Authors: Barrowcliffe T W , Tydeman M S , Kirkwood T B L , Thomas D P
Published: July 2018

An international collaborative study has been carried out to establish a reference plasma for Factor VIII-related activities. The freeze-dried reference plasma, coded 80/511, was assayed against fresh normal plasma, local standards and another freeze- dried plasma. There was good agreement between laboratories for the comparison of the two freeze-dried plasmas, but wide variation in the comparison of plasma 80/511 with fresh normal plasma and local standards, indicating the differences in Factor VIII content of local pooled plasmas. There were no significant differences between the one-stage and two-stage assays of VIII :C, or between electroimmunoassay (EIA) and immuno- radiometric (IRMA) assays of VIII R:Ag. However, in VIII R: RCoF (ristocetin co-factor) assays, the aggregometry methods gave lower values than the macroscopic and counting methods for the comparison of freeze-dried against fresh normal plasmas. From the combined results of assays against each laboratory’s fresh normal plasma, potencies were assigned to plasma 80/511.

Results from accelerated degradation studies indicated that losses of each VIII-related activity in plasma 80/511, when stored at -20° C, should be less than 0.01% per year, indicating its suitability to serve as a long-term reference preparation. Plasma 80/511 has been established by the WHO Expert Committee on Biological Standardization as the 1st International Reference Preparation for Factor VIII-Related Activities in Plasma.
Non-orthogonal configuration interaction with single substitutions for the calculation of core-excited states
Authors: Oosterbaan Katherine J. , White Alec F. , Head-Gordon Martin
Published: July 2018

In this paper, we present the non-orthogonal configuration interaction singles (NOCIS) method for calculating core-excited states of closed-shell molecules. NOCIS is a black-box variant of NOCI, which uses A different core-ionized determinants for a molecule with A atoms of a given element to form single substitutions. NOCIS is a variational, spin-pure, size-consistent ab initio method that dramatically improves on standard CIS by capturing essential orbital relaxation effects, in addition to essential configuration interaction. We apply it to the calculation of core-excitations for several smaller molecules and demonstrate that it performs competitively with other Hartree-Fock and DFT-based methods. We also benchmark it in several basis sets.
Invited Article: Label-free nerve imaging with a coherent anti-Stokes Raman scattering rigid endoscope using two optical fibers for laser delivery
Authors: Hirose Keigo , Fukushima Shuichiro , Furukawa Taichi , Niioka Hirohiko , Hashimoto Mamoru
Published: July 2018

A coherent anti-Stokes Raman scattering (CARS) rigid endoscope using two optical fibers to deliver excitation beams individually is developed. The use of two optical fibers allows the correction of longitudinal chromatic aberration and enhances the CARS signal by a factor of 2.59. The endoscope is used to image rat sciatic nerves with an imaging time of 10 s. Imaging of the rabbit prostatic fascia without sample slicing is also demonstrated, which reveals the potential for the application of the CARS endoscope to robot-assisted surgery.
Investigation of variable thermo-physical properties of viscoelastic rheology: A Galerkin finite element approach
Authors: Qureshi Imran Haider , Nawaz M. , Rana Shafia , Nazir Umar , Chamkha Ali J.
Published: July 2018

Galerkin finite element (GFEM) algorithm is implemented to investigate the variable viscosity, variable thermal conductivity and variable mass diffusion coefficient on viscoelasticity and non-Newtonian rheology of Maxwell fluid. Computer code is developed for weak form of FEM equations and validated with already published benchmark (a special case of present work). Theoretical results for velocities, temperature and concentration are displayed to analyze the effects of arising parameters including variable Prandtl number and variable Schmidt number. Shear stresses (only for Newtonian case) heat and mass fluxes at the elastic surface are computed and recorded in tabular form.
Visible spectroscopy diagnostics for tungsten source assessment in the WEST tokamak: First measurements
Authors: Meyer O. , Giacalone J. C. , Gouin A. , Pascal J. Y. , Klepper C. C. , Fedorczak N. , Lotte Ph. , Unterberg E. A. , Fehling D. T. , Harris J. H. ,   WEST Team
Published: July 2018

The present work concerns the measurements obtained with the Tungsten (W) Environment in Steady-state Tokamak (WEST) visible spectroscopy system during the first experimental campaign. This system has been developed in the framework of the WEST project that equipped the existing Tore Supra device with a tungsten divertor in order to test actively cooled tungsten Plasma Facing Components (PFC) in view of preparing for ITER operation. The goal of this diagnostic is to measure the PFC sources and the deuterium recycling with spectral, spatial, and temporal resolution adapted to the predicted power deposition profiles on the objects observed. Three kinds of PFCs are monitored: the Ion Cyclotron Resonance Heating (ICRH) antenna and Low Hybrid Current Drive (LHCD) launcher W limiters; one of the 6 W inner bumpers; and the upper and lower W divertors. Large-aperture in-vessel actively cooled optical systems (f-number ∼ 3) were installed for each view and connected to optical fibres. A total of 240 optical fibers can be distributed on various detection systems including a fast response-time, multi-channel, filtered photodetector-based “Filterscope” system, developed by Oak Ridge National Laboratory (USA) as well as grating spectrometers optimized for multi-sightline analysis. The first WEST experimental campaign conducted in 2017 has been dedicated to plasma start-up development during which the visible spectroscopy system has provided crucial information related to the impurity content first and then impurity sources. The diagnostic setup for that first experimental campaign was limited to the inner bumper and outer limiters but was sufficient to demonstrate that the optical setup was in accordance with the specifications. The radiance calibration procedure allowed us to estimate fluxes from the main limiter of about 8 × 1018 atoms/(s m2) and to show a first W source radial profile along the outboard limiter.
Novel nested saddle coils used in miniature atomic sensors
Authors: Wu Wenfeng , Zhou Binquan , Liu Gang , Chen Linlin , Wang Jing , Fang Jiancheng
Published: July 2018

A novel uniform magnetic field coil structure with two pairs of saddle coils nested is proposed in order to minish the aspect ratio without losing much field uniformity, which is significant in innovative miniature atomic instruments and sensors. Optimal configuration parameters are obtained from the Taylor expansion of the magnetic field. The remainder terms are used to estimate the field uniformity and optimize the configuration while minishing computation time. Compared with traditional saddle coils, the nested saddle coils have unique advantages in miniature applications where the aspect ratios are strictly limited. The optimized nested saddle coils were manufactured by Flexible Printed Circuit (FPC) technology and the magnetic field uniformities were verified experimentally using a flux-gate magnetometer. Furthermore, the example application of a miniature nuclear magnetic resonance (NMR) gyro demonstrates the practical use of the nested coils.
Photochemistry and spectroscopy of small hydrated magnesium clusters Mg+(H2O)n, n = 1–5
Authors: Ončák Milan , Taxer Thomas , Barwa Erik , van der Linde Christian , Beyer Martin K.
Published: July 2018

Hydrated singly charged magnesium ions Mg+(H2O)n, n ≤ 5, in the gas phase are ideal model systems to study photochemical hydrogen evolution since atomic hydrogen is formed over a wide range of wavelengths, with a strong cluster size dependence. Mass selected clusters are stored in the cell of an Fourier transform ion cyclotron resonance mass spectrometer at a temperature of 130 K for several seconds, which allows thermal equilibration via blackbody radiation. Tunable laser light is used for photodissociation. Strong transitions to D1–3 states (correlating with the 3s-3px,y,z transitions of Mg+) are observed for all cluster sizes, as well as a second absorption band at 4–5 eV for n = 3-5. Due to the lifted degeneracy of the 3px,y,z energy levels of Mg+, the absorptions are broad and red shifted with increasing coordination number of the Mg+ center, from 4.5 eV for n = 1 to 1.8 eV for n = 5. In all cases, H atom formation is the dominant photochemical reaction channel. Quantum chemical calculations using the full range of methods for excited state calculations reproduce the experimental spectra and explain all observed features. In particular, they show that H atom formation occurs in excited states, where the potential energy surface becomes repulsive along the O⋯H coordinate at relatively small distances. The loss of H2O, although thermochemically favorable, is a minor channel because, at least for the clusters n = 1-3, the conical intersection through which the system could relax to the electronic ground state is too high in energy. In some absorption bands, sequential absorption of multiple photons is required for photodissociation. For n = 1, these multiphoton spectra can be modeled on the basis of quantum chemical calculations.
Spin transition of ferropericlase under shock compression
Authors: Zhang N. B. , Cai Y. , Yao X. H. , Zhou X. M. , Li Y. Y. , Song C. J. , Qin X. Y. , Luo S. N.
Published: July 2018

Planar shock compression experiments are performed at 9–105 GPa on polycrystalline ferropericlase (Mg0.94Fe0.06)O to investigate its Fe2+ spin transition. Forward and reverse impact configurations are used to obtain Hugoniot and shock-state sound velocities. While wave profiles, shock velocity–particle velocity and pressure–density measurements show negligible/weak indications of a phase transition, the shock-state sound speed data clearly manifest a phase transition in the range of 36–62 GPa at the nanosecond time scales. These shock data reveal the phase transition as the spin transition identified in static compression experiments and first-principles calculations.