bluuebunny/crossref_metadata_2025 huggingface dataset:
A P-Selectin/CD62P Monoclonal Antibody (LYP-20), in Tandem with Flow Cytometry, Detects in vivo Activated Circulating Rat Platelets in Severe Vascular Trauma
Authors: Chignier Elza , Parise Maud , McGregor Lilian , Delabre Caroline , Faucompret Sylvie , McGregor John
Published: July 2018

P-selectin, also known as CD62P, GMP140 or PADGEM, is present in platelet a-granules and endothelial cell Weibel-Palade bodies and is very rapidly expressed on the surface of these cells on activation. In this study, an anti P-selectin monoclonal antibody (LYP20) was used, in tandem with flow cytometry, to identify activated platelets at the site of induced vascular trauma or in peripheral blood. Moreover, electron microscopy was performed to characterize sites of vascular trauma and quantify the number of adhering platelets. The same induced vascular trauma was observed to result into animals responding in 2 different ways (Group I, Group II) following the degree of platelet activation. Five rats, out of 14 with induced vascular trauma, had more than half of their circulating platelets expressing P-selectin when drawn at the site of the trauma (67.4% ± 3.44) or in peripheral blood (78.5% ± 2.5) (Group I). In the remaining 9 animals a much smaller proportion of circulating platelets expressed P-selectin when assayed from trauma sites (18% ± 3.34) or in peripheral blood (18.0% ± 4.30) (Group II). Enhanced P-selectin expression by circulating platelets in Group I, compared to Group II, appears to be linked to the degree of activated platelets adhering at sites of trauma (171 ± 15 × 103 platelets versus 48 ± 31 × 103 platelets per mm2). In the 5 control animals, that were not operated on, platelets expressing P-selectin when drawn at the site of a mock trauma (7.0% ± 1.84) or in the peripheral blood (11.2% ± 3.30) showed little activation. In addition, no platelet adhesion was seen on the vascular bed of these animals. Results from this study show that analysis of P-selectin (CD62P) expression, in circulating platelets, is a valuable and rapid marker of platelet activation following severe vascular trauma induced in rats. However, activated platelets were not detected to the same extent in the peripheral blood of all animals having undergone vascular trauma. It is conceivable that platelets, depending on the degree of activation, may be actively sequestered in organs and prevented from circulating. Alternatively, P-selectin may be rapidly endocytosed, or not expressed, by activated circulating platelets depending on the type of agonists implicated in vivo activation.
Association of a Variable Number of Tandem Repeats (VNTR) in Glycoprotein Ibα and HPA-2 Alloantigens
Authors: Simsek S , Bleeker P M M , van der Schoot C E , von dem Borne A E G Kr
Published: July 2018

The human platelet alloantigen HPA-2 (Koa/Kob) system is involved in two clinical syndromes, neonatal alloimmune thrombocytopenia and platelet transfusion refractoriness. Wb have previously described that the human platelet alloantigens HPA-2a(Kob) and HPA-2b(Koa), are caused by a Thrl45Met amino acid polymorphism in the N-terminal globular domain of the human platelet glycoprotein (GP) Ibα. In the present study the question was addressed as to whether a genetic association exists between this Thrl45Met polymorphism and the recently described variable number of tandem repeat (VNTR) polymorphism in GP Ibα. Such an association has already been suggested by serological analysis (Ishida et al., 1991). This VNTR polymorphism results from a 13-amino-acid sequence repeat in the macroglycopeptide region of GP Ibα. Therefore, we developed a PCR method to analyze the VNTR region of 106 normal individuals who were also analyzed for the HPA-2 polymorphism. In this method genomic DNA derived from mononuclear cells was purified, the polymorphic region was amplified by PCR and was electrophoresed on agarose gels. Differences in the size of the PCR products made VNTR typing possible. Genotyping for the HPA-2 system was done by allele-specific restriction site analysis of PCR products with the restriction enzyme Sfa NI. The DNA derived from 12 HPA-2 (a-b+) subjects, contained only the B variant (with 3 repeats) of the VNTR polymorphism. The D variant (with 1 repeat) was only found in HPA-2a positive individuals. The C variant (with 2 repeats) was found to be strongly associated with HPA-2a. However, two members of a family with a HPA-2 (a+b+) genotype were found to be homozygous for the C variant of the VNTR polymorphism. This shows that the C variant can also be associated with HPA-2b. The A variant (with 4 repeats) was not encountered in the population studied. The strong association of HPA-2 and VNTR polymorphism, lying 761 bp apart on the GP Ibα gene, indicates linkage disequilibrium.
The Role of the Finger Domain of Tissue-type Plasminogen Activator (t-PA) and Plasminogen Activator Inhibitor 1 (PAI-1) in Initiation and Progression of Thrombolysis
Authors: Stringer Harold A R , van Swieten Peter , Horrevoets Anton J G , Smilde Annelies , Pannekoek Hans
Published: July 2018

We further investigated the role of the finger (F) and the kringle-2 (K2) domains of tissue-type plasminogen activator (t-PA) in fibrin-stimulated plasminogen activation. To that end, the action of purified (wt) t-PA or of variants lacking F (del.F) or K2 (del.K2) was assessed either in a static, human whole blood clot-lysis system or in whole blood thrombi generated in the “Chandler loop”. In both clot-lysis systems, significant differences were observed for the initiation of thrombolysis with equimolar concentrations of the t-PA variants. A relatively minor “lag phase” occurred in thrombolysis mediated by wt t-PA, whereas a 6.4-fold and 1.6-fold extension is found for del.F and del.K2, respectively. We observed identical lag-times, characteristic for each t-PA variant, in platelet-rich heads and in platelet-poor tails of thrombi. Since plasminogen activator inhibitor 1 (PAI-1) is preferentially retained in the platelet-rich heads, we conclude that the inhibitor does not interfere with the initial stage of thrombolysis but exerts its action in later stages, resulting in a reduction of the rate of clot lysis. A complementation clot-lysis assay was devised to study a potential interplay of del.F and del.K2. Accordingly, clot lysis was determined with combinations of del.F and del.K2 that were inversely varied in relation to equipotent dosage to distinguish between additive, antagonistic or synergistic effects of these variants. The isobole for combinations of del.F and del.K2 shows an independent, additive action of del.F and del.K2 in clot lysis. Under the conditions employed, namely a relatively high concentration of fibrin and Glu-plasminogen and a low concentration of t-PA variant, our data show: i) the crucial role of the F domain and the lack of effect of PAI-1 in initiation of thrombolysis, ii) the lack of importance of the fibrimbinding domains of t-PA and the regulatory role of PAI-1 in advanced stages of thrombolysis.
Neonatal Platelets Are Less Reactive than Adult Platelets to Physiological Agonists in Whole Blood
Authors: Rajasekhar Damodara , Kestin Anita S , Bednarek Francis J , Ellis Patricia A , Barnard Marc R , Michelson Alan D
Published: July 2018

Previous studies have reported that the platelets of healthy term neonates have either diminished or normal reactivity compared to the platelets of adults. To circumvent the methodologic problems of previous studies, we used a whole blood flow cytometric method to study neonatal platelet reactivity to thrombin, a combination of ADP and epinephrine, and U46619 (a stable thromboxane A2 analogue). Inclusion in the assay of the peptide GPRP (an inhibitor of fibrin polymerization) enabled us to study platelet reactivity to human α-thrombin in whole blood. Umbilical cord blood and day 1 peripheral blood were collected from 30 healthy term neonates and compared to peripheral blood from 20 normal adults. In whole blood samples without added agonist, there were no significant differences between neonates and adults in the platelet binding of monoclonal antibodies 6D1 (GPIb-specific) or 7E3 (GPIIb-IIIa complex-specific). As determined by S12 (a P-selectin-specific monoclonal antibody), neither neonates nor adults had circulating degranulated platelets. However, in both cord and peripheral whole blood samples, neonatal platelets were significantly less reactive than adult platelets to thrombin, ADP/epinephrine, and U46619, as determined by the extent of increase in the platelet surface expression of P-selectin and the GPIIb-IIIa complex, and the extent of decrease in the platelet surface expression of the GPIb-IX complex. For example, as compared to maximal platelet surface P-selectin in adults (with thrombin 10 U/ml), thrombin 1 U/ml resulted in platelet surface P-selectin of 95 ± 2% (mean ± S.E.M.) in adult peripheral blood, but only 70 ± 4% in cord blood and 70 ± 3% in neonatal peripheral blood (p <0.0001). Thrombin 0.1 U/ml resulted in platelet surface P-selectin of 49 ± 4% in adult peripheral blood, but only 10 ± 2% in cord blood and 17 ± 2% in neonatal peripheral blood (p α0.0001). Similar results were obtained in a washed platelet system. In summary: 1) Compared to adult controls, neonatal platelets are hyporeactive to thrombin, a combination of ADP and epinephrine, and a thromboxane A2 analogue in the physiologic milieu of whole blood. 2) The hyporeactivity of neonatal platelets compared to adult platelets is the result of a defect intrinsic to neonatal platelets. 3) Whole blood flow cytometry is particularly advantageous for neonatal studies because only 5 μl of blood per assay is required.
Increased Levels of Soluble Adhesion Molecules in Type 2 (Non-Insulin Dependent) Diabetes mellitus Are Independent of Glycaemic Control
Authors: Steiner M , Reinhardt K M , Krammer B , Ernst B , Blann A D
Published: July 2018

Patients with Type 2 (non-insulin dependent) diabetes mellitus are at increased risk of thrombosis and the premature development of atherosclerosis. This may be related to damage to the endothelium (which may be the primary target tissue for the disease process) resulting from a loss of normal glycaemic metabolic control. Thus changes in endothelial cell function, such as modified release of soluble leukocyte and platelet adhesion molecules, may be important. Accordingly, E-selec-tin, von Willebrand factor (vWf), vascular cell adhesion molecule (VCAM) and intercellular adhesion molecule (ICAM) were measured in serum from 60 patients and 76 controls. Raised levels of vWf (p = 0.0002), E-selectin (p <0.0001) and VC AM (p = 0.003) in patient’s samples failed to correlate with glycaemic control as assessed by levels of fructosamine and glycated haemoglobin, or with 24 h urine albumin. Levels of ICAM were not increased in our patients. Levels of the two endothelial cell products, vWf and E-selectin, failed to correlate although E-selectin correlated with low density lipoprotein cholesterol (p = 0.016). vWf correlated with VCAM (p <0.001) and hypertension (p = 0.032). We conclude that levels of soluble adhesion molecules vWf, E-selectin and VCAM are raised in Type 2 diabetes mellitus. The mechanisms for these changes appear to be independent of glycaemic control but may relate to concurrent hypertension and/or hypercholes-terolaemia.
The Effects of Insulin-Like Growth Factor-1 on Plasminogen Activator Inhibitor-1 Synthesis and Secretion: Results from In Vitro and In Vivo Studies
Authors: Padayatty S J , Orme S , Zenobi P D , Stickland M H , Belchetz P E , Grant P J
Published: July 2018

In vitro studies have shown that insulin and IGF-1 releases the fibrinolytic inhibitor plasminogen activator inhibitor-1 (PAI-1) from cells of hepatic origin. To investigate the effects of IGF-1 on fibrinolysis: 1) cultured hepatoma cells were grown in the presence of IGF-1 and media collected for secreted PAI-1 and cells probed for PAI-1 mRNA, 2) 8 hypopituitary patients were treated with recombinant human growth hormone (rhGH) and 3) 5 type 2 diabetic patients were treated with recombinant human IGF-1 (rhIGF-1). Treatment of Hep G2 cells with IGF-1 (1000 ng/ml) increased secretion of PAI-1 from a median value of 80 ng/106 cells (range 21-91) to 144 ng/106 cells (range 128-169) after 24 h (p <0.01). Synthesis of PAI-1 mRNA increased in a similar fashion. Treatment of hypopituitary patients with rhGH led to an increase in circulating IGF-1 from a mean value of 166 (range 41-324) ng/ml at baseline to 322 (77-575) ng/ml at 4 weeks and 259 (104-533) ng/ml after 8 weeks (p <0.02). Despite this, no changes in circulating PAI-1 or fibrinolysis occurred. Type II diabetic patients treated with rhIGF-1 showed an increase in circulating IGF-1 from a mean value of 120 ng/ml (range 109-196), at baseline to 823 ng/ml (585-894) after 5 days. This also was not associated with changes in circulating PAI-1 or in fibrinolysis. The results confirm that IGF-1 induces the synthesis of PAI-1 in Hep G2 cells. However, marked increases in IGF-1 had no effect on circulating PAI-1 or fibrinolysis.
Fluorogenic Fibrinogen and Fibrin Facilitate Macromolecular Assembly and Dynamic Assay of Picomolar Levels of Plasminogen Activators under Well Mixed Conditions
Authors: Wu Jung-He , Diamond Scott L
Published: July 2018

Fibrinogen labeled with fluorescein isothiocyanate (FITC) was tested for its ability to serve as a template for macromolecular assembly as well as to provide a fluorogenic signal to allow continuous monitoring of plasminogen activation and fibrinolysis. As dilute solutions of FITC-fibrinogen or FITC-fibrin fiber suspension were degraded during lysis, release of fluorescent fragments abolished proximity- based quenching and resulted in a 2.0- or 3.6-fold increase in fluorescence intensity, respectively. Addition of plasmin at a final concentration of 10 pM to FITC-fibrinogen (10 nM) produced a detectable level of fluorescence dequenching. The assay had sufficient sensitivity to detect plasmin activity in the presence of excess antiplasmin activity, indicating the dissociation of a reversible antiplasmin-plasmin complex. The detection limit of the reaction assay was 20 pM and 200 pM of recombinant tPA and urokinase, using 10 nM FITC-fibrin and 10 nM and 5 nM plasminogen, respectively. The 10-fold greater sensitivity of the assay for tPA was likely due to the molecular assembly of tPA and plasminogen on the FITC-fibrin. Addition of thrombin (1 U/ml) and plasmin (0.1 nM) to 10 nM FITC-fibrinogen produced fluorescence quenching at first due to fibrinogen polymerization followed by dequenching due to fibrinolysis. Addition of 10 mM ∈-aminocaproic acid to mixtures of thrombin and plasmin allowed the quenching assay of thrombin activity in the presence of active plasmin. FITC-fibrinogen could be copolymerized with recalcified platelet poor plasma (isolated from citrated whole blood) to yield fibrin that was fluorogenic. Dequenching was observed when plasmin was used to degrade the fibrin formed from the platelet poor plasma. Given the large signal generated upon degradation of the fluorogenic fibrin(ogen), at least 105 determinations can be run from 100 mg of FITC-labeled fibrinogen using a standard fluorimeter and 0.1 to 3.0 ml reaction volumes. The versatility of the fluorogenic fibrinogen substrate allowed the configuration of assays to detect and measure the activity of thrombin, plasmin, tPA, uPA, and α2-antiplasmin. The ability to assemble blood proteins on a fluorogenic fibrinogen or fibrin template provides unique opportunities for the dynamic study of binding and enzymatic events on the fibrin surface under well mixed conditions.
Von Willebrand Activity of Low Molecular Weight Human Factor VIII Increases by Binding to Gold Granules
Authors: Furlan Miha , Perret Beat A , Beck Eugene A
Published: July 2018

Human factor VIII/von Willebrand protein is a population of multimers which vary in size but contain apparently identical subunits. Large-molecular-weight forms possess higher ristocetin cofactor/von Willebrand activity than the native smaller oligomers. Disulfide reduction of large factor VIII multimers results in progressively decreasing molecular size and a loss of ristocetin cofactor activity. Small molecular forms of factor VIII were adsorbed onto gold granules (average diameter 20-30 nm) and thereby increased their ristocetin cofactor activity. The amount of adsorbed material and the extent of activation were dependent on the pH of the colloid suspension. The maximum recovery of von Willebrand activity was observed at pH 4.75. Aggregation of fixed human platelets by factor VIII-coated gold particles was dependent on ristocetin concentration and was not competitively inhibited by unbound low-molecular-weight factor VIII. These results suggest that the subunits of the native small factor VIII species possess potential binding affinity for platelet receptors, which is manifested following formation of large factor VIII polymers. We conclude that an optimal size of remarkably high molecular weight is required for efficient aggregation of platelets by factor VIII as occurs during the primary phase of hemostasis.
Blood Fibrinolytic System in Rana tigrina
Authors: Srivastava V M , Dube B , Dube R K , Agarwal G P , Ahmad N
Published: July 2018

Fibrinolytic activity is well demonstrable in the blood of Rana tigrina. There occurs prompt lysis of diluted plasma; and the plasma euglobulin fraction shows lysis on both unheated and heated fibrin (human or bovine) plates, implying the presence of plasmin-like enzyme in this fraction. The fibrinolytic activity is remarkably inhibited by the erythrocyte-lysate and is moderately enhanced by leucocytes-thrombocytes. EACA suppresses the lysis of dilute cell-free plasma clots at concentration of l0-4M or more, possibly indicating the presence of plasminogen activator in the plasma. Activation of fibrinolysis by human urokinase and not by streptokinase, shows the probable presence of plasminogen and absence of proactivator.
Heterogeneity of Molecular Size of Factor Vlll/von Willebrand Factor in von Willebrand's Disease
Authors: Mikami S , Takahashi Y , Nishino M , Okubo Y , Fukui H
Published: July 2018

Patterns of VIIIR:AG in the plasma and its fractions, cryoprecipitate and cryosupernatant, from various types of von Willebrand’s disease (vWd) were observed by SDS 1.5% polyacrylamide gel electrophoresis - crossed immunoelectrophoresis (SDS PAGE - CIE).

VIIIR:AG in normal cryoprecipitate showed several precipitin peaks which correspond to molecular weights ranging from 8 X 105 to 1 X 10
7 daltons and are similar to those in normal plasma. Normal cryosupernatant VIIIR: AG gave smaller molecular weights from 8 X 10
5 to 2 X 10
6 daltons.

VIIIR:AG in the plasma and cryoprecipitate from 2 patients with classical vWd gave low precipitin peaks with molecular weights in normal range. VIIIR:AG from 2 patients with subgroup A variant which showed fast anodal migration on the conventional CIE, presented 3 peaks with molecular weights of 8 X 105 to 3 X 106 which are similar to those in normal cryosupernatant. VIIIR: AG from 2 patients with subgroup B variant which showed normal migration on the CIE, gave normal patterns through all fractions.
Substrate Recognition by Vitamin K-Dependent Carboxylase
Authors: Ulrich Magda M W , Soute Berry A M , van Haarlem L Johan M , Vermeer Cees
Published: July 2018

Decarboxylated osteocalcins were prepared and purified from bovine, chicken, human and monkey bones and assayed for their ability to serve as a substrate for vitamin K-dependent carboxylase from bovine liver. Substantial differences were observed, especially between bovine and monkey d-osteocalcin. Since these substrates differ only in their amino acid residues 3 and 4, it seems that these residues play a role in the recognition of a substrate by hepatic carboxylase.
A Quantitative Enzyme Immunoassay for Primary Fibrinogenolysis Products in Plasma
Authors: Koppert P W , Kuipers W , Nobel B Hoegee-de , Brommer E J P , Koopman J , Nieuwenhuizen W
Published: July 2018

We have developed a two-step enzyme immunoassay (EIA) that allows the quantitation of degradation products derived from fibrinogen (FbgDP) and that does not detect degradation products derived from cross-finked (XDP) or noncrosslinked fibrin (fdp).

The EIA is based on two monoclonal antibodies (FDP-14 and Y-18), developed in our institute. FDP-14 is used as catching antibody. It complexes exclusively with degradation products, irrespective whether these are derived from fibrinogen or from fibrin. It does not complex with intact fibrinogen or fibrin. Y-18 is reactive with fibrinogen and fibrinopeptide A-comprising fibrinogen fragments. It is used, conjugated with horse-radish peroxy-dase, as tagging antibody.

The FbgDP-EIA is highly specific, accurate and sensitive. The coefficient of variation is between 3 and 8%; the lower detection limit is less than 0.025 μg/ml.

The assay has been applied to plasma from patients with suspected disseminated intravascular coagulation (DIC), to plasma from patients undergoing streptokinase (SK) therapy for acute myocardial infarction and to plasma from newborn babies.

DIC patients had no or very low levels of FbgDP, but high levels of other degradation products, SK-treated patients showed high levels of degradation products two hours after termination of the SK infusion. A considerable fraction of these degradation products was shown to be FbgDP. Plasma from newborn babies contained elevated levels of FbgDP associated with prolonged prothrombin times.
Mapping of Epitopes on Human Tissue-Type Plasminogen Activator with Recombinant Deletion Mutant Proteins
Authors: Zonneveld Anton-Jan van , Veerman Harry , Brakenhoff Just P J , Aarden Lucien A , Cajot Jean-Francois , Pannekoek Hans
Published: July 2018

An antigen assay based on a monoclonal antibody directed against the light chain of tissue-type plasminogen activator (t-PA) was developed to quantify seven recombinant (r) t-PA deletion mutant proteins. These recombinant proteins were then employed to map different epitopes on t-PA which interact with a panel of twenty-three monoclonal anti-t-PA antibodies. Twenty were directed against domains on the heavy chain, two against the “finger” domain, three against the “epidermal growth factor-like” domain, five against the kringle 1 domain, and ten against the kringle 2 domain. Only three monoclonal anti-t-PA antibodies interact with the light chain. The finding that the epitopes of each of the monoclonals could be determined with the deletion mutant proteins supports the hypothesis of autonomous folding of structural domains and emphasizes the validity of the use of the recombinant t-PA-deletion mutant proteins for structure-function studies.
The Animal Models for Hemorrhage and Thrombosis in the Neonate
Authors: Kisker C Thomas
Published: July 2018

Animal models have added significantly to our understanding of adult hemorrhagic and thrombotic diseases. Few models, however, have been developed for studies of the hemostatic disorders in the fetus and newborn. This report reviews the current information on animal models of fetal and neonatal hemostasis. The requirements of a relevant model are addressed and previous studies using fetal and neonatal animal models are reviewed. A recommendation of a single animal for all studies of fetal and neonatal hemostasis is not possible. However, the lamb has been the most frequently studied and appears to provide relevant information regarding normal development and the factors which may adversely influence hemostasis in the fetus and newborn.
Metformin Decreases the High Plasminogen Activator Inhibition Capacity, Plasma Insulin and Triglyceride Levels in Non-Diabetic Obese Subjects
Authors: Vague Ph , Juhan-Vague I , Alessi M C , Badier C , Valadier J
Published: July 2018

We have previously observed a positive correlation between Plasminogen Activator Inhibition capacity (PA Inhibition), Body Mass Index (BMI) and plasma insulin levels in a population of non diabetic subjects. The anti diabetic biguanide Metformin which decreases insulin resistance has been reported to increase the blood fibrinolytic activity. Therefore we have studied the effect of Metformin on PA Inhibition levels in obese subjects with normal glucose tolerance. Eighteen obese women (O) (BMI: 31.4 ± 1.13, m ± S.E.M.) were compared to age matched controls (C) (BMI: 20.2 ± 0.8) and randomized to a 15 days treatment by Metformin (M) (1.7 g/day) or placebo (P) in a double blind study while on a weight maintaining diet. O compared to C had higher levels (m ± S.E.M.) of PA Inhibition (9 ± 1.8 IU/ml, versus 2.88 ± 0.29 p <0.01), lower euglobulin fibrinolytic activity (EFA) (4.95 ±1.17 mm versus 9 ± 0.29 p <0.05), higher plasma insulin (24.1 ±2.1. uU/ml), versus 12 ± 1 p <0.01) and triglyceride (1.32 ± 0.16 mmol/1, versus 0.8 ± 0.08 p <0.05). After 15 days of treatment, in group M a significant decrease in PA Inhibition (5.51 ± 1.4, versus 9.48 ±2.1 p <0.05) in plasma insulin (18.5 ±0.1, versus 24.5 ± 3.5, p <0.05) and plasma triglyceride (1.08 ± 0.1, versus 1.47 ± 0.3 p <0.05) and an increase in EFA (6.50 ± 0.28, versus 5.25 ± 0.35 p <0.05) were observed. No significant variation was observed in group P.
Using a Monoclonal Antibody to Identify Patients with Type I and Type II von Willebrand’s Disease
Authors: Hall Jeffrey D , Willis Dean W , Evatt Bruce L , Jackson Debra W
Published: July 2018

Three monoclonal antibodies produced against vWF:Ag by conventional hybridoma technique did not inhibit factor VIII coagulant activity (F.VIII:C) but did inhibit VIII ristocetin cofactor activity. The antibodies were used in an indirect competitive ELISA for quantifying von Willebrand’s antigen (vWF: Ag) and compared with values obtained by the Laurell technique using commercial antibody by means of a ratio: ELISA/Laurell. For one monoclonal BD2-CC9, vWF:Ag values obtained in the two assays were in good agreement for normal and hemophilia A plasmas (normal, n = 19, ratio = 1.13 ± .17, hemophilia A, n = 10, ratio = 0.91 ± .15). However, type II vWD patients had a disproportionately low value of vWF: Ag with the ELISA. Use of the ratio normalized the difference among individual plasma values and allowed a significant separation of type II vWD plasma (n = 9, ratio = 0.46 ± .19) from normal plasma (p = .0001) and type I vWD plasma (n = 8, ratio = 1.52 ± .34) from type II vWD plasma (p = .0003) using BD2-CC9. Although the sample size was small, the greater degree of discrimination among the vWD plasmas tested with BD2-CC9 (compared with the other two antibodies [CA3-AE4, CC6-BG10]) suggests that this antibody may recognize conformational epitopes that reflect the degree of multimeric polymerization of the vWF molecule rather than simply recognize a decreased number of antigenic sites in a basic subunit. BD2-CC9 may be valuable in investigating the various types of vWD and/or the process of polymerization of this complex protein.
Platelet Procoagulant Properties Studied with Snake Venom Prothrombin Activators
Authors: Speijer Han , Govers-Riemslag José W P , Zwaal Robert F A , Rosing Jan
Published: July 2018

Purified snake venom prothrombin activators were used to probe the procoagulant properties of platelet membranes. Human platelets were able to stimulate prothrombin activation by the venom activators from Oxyuranus scutellatus and Notechis scutatus, while the prothrombin activator from Echis carinatus was not affected by the presence of platelets. The prothrombinconverting activity of platelets was further studied with the venom activator from Oxyuranus scutellatus and with the factor Xa-Va complex as prothrombin activating enzymes. Stimulation of platelets with collagen, collagen plus thrombin or with the Ca-ionophore A23187 resulted in a considerable increase of platelet prothrombin converting activity probed with the factor Xa-Va complex as well as with the prothrombin activator from Oxyuranus scutellatus. The stimulatory effect of activated platelets on the rates of prothrombin activation by Oxyuranus scutellatus was similar to that determined for factor Xa-Va-catalyzed prothrombin activation. Compared to non-stimulated platelets, platelets stimulated with thrombin plus collagen exposed 20-times more procoagulant sites for as well the factor Xa-Va complex, as for the venom activator from Oxyuranus scutellatus. The actual number of procoagulant sites per platelet determined with the factor Xa-Va complex was in close agreement with the number of sites determined with the venom activator. Also the time course of appearance of procoagulant activity during platelet stimulation by collagen plus thrombin was comparable for both activator complexes. Phospholipase A2 treatment of stimulated platelets resulted in an almost complete loss of their ability to stimulate prothrombin activation by the enzyme from Oxyuranus scutellatus or by factor Xa-Va complex. The findings presented in this paper suggest: a) that the factor Xa-Va complex and the prothrombin activator from Oxyuranus scutellatus recognize the same procoagulant sites on both stimulated and unstimulated platelets and b) that negatively-charged phospholipids are essential components of these procoagulant sites.
Vulvar Hemangioma: Case Report
Authors: Silva Janine Medeiros da , Calife Emily Ramos , Cabral João Victor de Sousa , Andrade Hildemárzio Pinheiro Falcão de , Gonçalves Ana Katherine
Published: July 2018

Hemangioma is a benign neoplasm that may affect the vulva, and it can cause functional or emotional disability. This article reports the case of a 52-year-old female patient with a history of a genital ulcer for the past 3 years and who had undergone various treatments with creams and ointments. The patient was biopsied and diagnosed with vulvar hemangioma and was subsequently submitted to surgical excision of the lesion. We emphasize the importance of following the steps of the differential diagnosis and proceeding with a surgical approach only if necessary.
Acute Otologic Infections in Pediatric Patients
Authors: Tipton Courtney , Honsinger Kristen , Harris Michael , Malhotra Prashant
Published: July 2018

This article summarizes significant acute infections involving the pediatric temporal bone. First, the management of acute otitis media (AOM) is discussed, including the medical and surgical management of invasive intracranial and extracranial complications associated with advanced disease. The clinical and radiographic findings, microbiology, and management of acute mastoiditis are discussed in greater detail, followed by the presentation and treatment of acute otitis externa (AOE). Finally, we discuss infectious considerations in auditory implants. The indications and use of both cochlear implants (CI) and bone conduction hearing implants have rapidly expanded in children, requiring greater understanding of managing infections in the context of these devices.
Long wavelength stacking induced shift of the near-infrared photoluminescence from unintentional MOVPE grown InGaSb/GaSb quantum wells
Authors: Ahia Chinedu Christian , Tile Ngcali , Navarro Amalia , Blanco Beatriz Galiana , Botha Johannes Reinhardt
Published: July 2018

The effect of stacking on the near-infrared photoluminescence (NIR-PL) of InGaSb/GaSb quantum wells (QWs) which were inadvertently formed during an attempt to fabricate stacked InSb/GaSb quantum dots (QDs) using atmospheric pressure Metalorganic Vapor Phase Epitaxy (MOVPE) are investigated in this work. The morphology of uncapped dots was studied by means of scanning probe microscopy (SPM) which shows a significant deviation in the shape and density of dots grown directly on the buffer compared to those that terminated an “embedded-dot” sample. Cross-sectional scanning transmission electron microscopy (STEM) and transmission electron microscopy (TEM) of the capped structures clearly revealed the formation of QWs in the capped structures. An increase in the number of InSb QD-layers, which metamorphosed into QWs, was observed to cause an increase in the luminescence spectral line width and a long-wavelength shift of the QW PL lines, together with an enhancement in the strength of PL emission. Variations in layer thicknesses and alloy composition introduced as a result of inter-diffusion of Ga and In which is enhanced by the prolonged annealing time of the QDs (during spacer/cap layer deposition) and In adatom migration is suggested to alter the morphology of the capped dots and induce a change in PL peak positions and the spectral linewidth of the NIR low energy lines.
Small-amplitude three-dimensional structures in magnets
Authors: Borisov A. B. , Kiselev V. V. , Raskovalov A. A.
Published: July 2018

A new class of small-amplitude magnetic defects has been discovered in an unbounded medium and film of three-dimensional ferromagnets in the Heisenberg model. Such structures contain sources and vortices. It is shown that their dipolar configurations have finite energy. Stability of the discovered structures is discussed.
A combination of imaging techniques reveals a new method of measuring irregular dust in plasmas
Authors: Liebendorfer Adam
Published: July 2018

By bringing together long-distance microscopy with phase-resolve resonance, researchers have measured the charge properties of zinc oxide double tetrapod dust particles.
Optogalvanic gas sensor based on Rydberg excitation shows promise for NO detection
Authors: Michaud Sarah
Published: July 2018

Results from a proof-of-concept study show that selective Rydberg excitations could be used to create optogalvanic gas sensors with promising sensitivity and selectivity.
The use of face-threatening acts in the construction of in- and out-group identities in British parliamentary debates
Authors: Mollin Sandra
Published: July 2018

Identity construction is group membership construction in that humans bring their individual selves into being by declaring and performing their belonging to in-groups which are constructed in contrast to out-groups, as suggested in Tajfel’s theory of social identity. In parliamentary discourse, the establishment and reinforcement of in- and out-group identities is particularly important, since parliamentary discourse represents an institutionalized arguing game of ‘us’ versus ‘them’ (between political parties). One decisive way in which these group identities are construed and maintained is through the use of face-threatening acts (FTAs), analyzed here in British House of Commons debates on health policy. A taxonomy of FTAs in this context is developed, allowing for an analysis of addressers and addressees, and close interpretation of examples leads to the conclusion that FTAs are used to denigrate the out-group and strengthen in-group identification at the same time.
“And you know, Jeremy, my father came from a very poor background indeed”
Authors: Fetzer Anita
Published: July 2018

This chapter examines the discursive construction of identity in political discourse and considers collective identities as the default in that context. It utilises an integrated approach informed by interactional sociolinguistics and discourse pragmatics. Departing from the premise that discursive identities are co-constructed, reconstructed and – possibly – deconstructed in and through the process of communication, it focuses on those contexts in which political agents depart from the default by entextualising non-collective identities, e.g., private-domain-anchored family person or ordinary citizen. The ‘doing’ and ‘undoing’ of discursive identities in discourse is reflected in the importation of private-domain-anchored communicative styles and genres, such as colloquial expressions and small stories, contributing to the ongoing process of hybridisation of institutional discourse in general and political discourse in particular. The discursive construction, re- and deconstruction of identities in political discourse is a multifaceted endeavour which exploits the structural, pragmatic and cognitive constraints of a discourse genre as well as those of institution and society.
Nations as persons
Authors: Musolff Andreas
Published: July 2018

The paper analyses the construal of collective identities in the Middle East conflict, with special regard to the nation-as-person metaphor. This metaphor has been highlighted by proponents of Conceptual Metaphor Theory and Critical Metaphor Analysis as being instrumental in conceptualizing collective political entities as (pseudo-)personal identities. On the other hand, it has been critically argued that the nation-as-person metaphor should not be over-generalized and it has even been condemned as a fallacious theoretical construct. In view of the metaphor’s controversial status, the paper studies a corpus of ten speeches delivered by the Israeli and Palestinian political leaders B. Netanyahu and M. Abbas to the UN General assemblies in the period 2011–2015. Instances of emphatic use and enactment of the nation-as-person metaphor by the speakers are analysed in detail for their contextual implications and their function in collective identity-construction. The main finding is that whilst the nation-as-person metaphor is not ubiquitous in a statistical sense, it informs the fundamental pragmatic stance of the speakers as personifications of their nations’ collective identities vis-à-vis other nations. In conclusion, it is argued that such collective identity construction both expresses and shapes the progress of conflict communication.
From similarity to evidentiality
Authors: Gipper Sonja
Published: July 2018

This chapter argues that the synchronic uses of the Yurakaré (isolate, central Bolivia) polyfunctional suffix ‑shi plausibly reflect a diachronic path of semantic extension, first from a derivational suffix expressing similarity to an uncertain visual/perceptual evidential, and from there to an inferential evidential. Evidence for this claim comes from the correlation of the properties of the synchronic uses with well-known tendencies of semantic change, and from a sociolinguistic analysis of the synchronic uses of ‑shi. A cross-linguistic comparison further shows that there are various other languages with a similar evidential marker. For some of these languages, similar paths of diachronic development are plausible.
MDPbiome: microbiome engineering through prescriptive perturbations
Authors: García-Jiménez Beatriz , de la Rosa Tomás , Wilkinson Mark D
Published: July 2018

Motivation

Recent microbiome dynamics studies highlight the current inability to predict the effects of external perturbations on complex microbial populations. To do so would be particularly advantageous in fields such as medicine, bioremediation or industrial scenarios.

Results

MDPbiome statistically models longitudinal metagenomics samples undergoing perturbations as a Markov Decision Process (MDP). Given a starting microbial composition, our MDPbiome system suggests the sequence of external perturbation(s) that will engineer that microbiome to a goal state, for example, a healthier or more performant composition. It also estimates intermediate microbiome states along the path, thus making it possible to avoid particularly undesirable/unhealthy states. We demonstrate MDPbiome performance over three real and distinct datasets, proving its flexibility, and the reliability and universality of its output ‘optimal perturbation policy’. For example, an MDP created using a vaginal microbiome time series, with a goal of recovering from bacterial vaginosis, suggested avoidance of perturbations such as lubricants or sex toys; while another MDP provided a quantitative explanation for why salmonella vaccine accelerates gut microbiome maturation in chicks. This novel analytical approach has clear applications in medicine, where it could suggest low-impact clinical interventions that will lead to achievement or maintenance of a healthy microbial population, or alternately, the sequence of interventions necessary to avoid strongly negative microbiome states.

Availability and implementation

Code (https://github.com/beatrizgj/MDPbiome) and result files (https://tomdelarosa.shinyapps.io/MDPbiome/) are available online.

Supplementary information

Supplementary data are available at Bioinformatics online.
Computational enhancement of single-cell sequences for inferring tumor evolution
Authors: Miura Sayaka , Huuki Louise A , Buturla Tiffany , Vu Tracy , Gomez Karen , Kumar Sudhir
Published: July 2018

Motivation

Tumor sequencing has entered an exciting phase with the advent of single-cell techniques that are revolutionizing the assessment of single nucleotide variation (SNV) at the highest cellular resolution. However, state-of-the-art single-cell sequencing technologies produce data with many missing bases (MBs) and incorrect base designations that lead to false-positive (FP) and false-negative (FN) detection of somatic mutations. While computational methods are available to make biological inferences in the presence of these errors, the accuracy of the imputed MBs and corrected FPs and FNs remains unknown.

Results

Using computer simulated datasets, we assessed the robustness performance of four existing methods (OncoNEM, SCG, SCITE and SiFit) and one new method (BEAM). BEAM is a Bayesian evolution-aware method that improves the quality of single-cell sequences by using the intrinsic evolutionary information in the single-cell data in a molecular phylogenetic framework. Overall, BEAM and SCITE performed the best. Most of the methods imputed MBs with high accuracy, but effective detection and correction of FPs and FNs is a challenge, especially for small datasets. Analysis of an empirical dataset shows that computational methods can improve both the quality of tumor single-cell sequences and their utility for biological inference. In conclusion, tumor cells descend from pre-existing cells, which creates evolutionary continuity in single-cell sequencing datasets. This information enables BEAM and other methods to correctly impute missing data and incorrect base assignments, but correction of FPs and FNs remains challenging when the number of SNVs sampled is small relative to the number of cells sequenced.

Availability and implementation

BEAM is available on the web at https://github.com/SayakaMiura/BEAM.
CNEFinder: finding conserved non-coding elements in genomes
Authors: Ayad Lorraine A K , Pissis Solon P , Polychronopoulos Dimitris
Published: July 2018

Motivation

Conserved non-coding elements (CNEs) represent an enigmatic class of genomic elements which, despite being extremely conserved across evolution, do not encode for proteins. Their functions are still largely unknown. Thus, there exists a need to systematically investigate their roles in genomes. Towards this direction, identifying sets of CNEs in a wide range of organisms is an important first step. Currently, there are no tools published in the literature for systematically identifying CNEs in genomes.

Results

We fill this gap by presenting CNEFinder; a tool for identifying CNEs between two given DNA sequences with user-defined criteria. The results presented here show the tool’s ability of identifying CNEs accurately and efficiently. CNEFinder is based on a k-mer technique for computing maximal exact matches. The tool thus does not require or compute whole-genome alignments or indexes, such as the suffix array or the Burrows Wheeler Transform (BWT), which makes it flexible to use on a wide scale.

Availability and implementation

Free software under the terms of the GNU GPL (https://github.com/lorrainea/CNEFinder).
Ontology-based validation and identification of regulatory phenotypes
Authors: Kulmanov Maxat , Schofield Paul N , Gkoutos Georgios V , Hoehndorf Robert
Published: July 2018

Motivation

Function annotations of gene products, and phenotype annotations of genotypes, provide valuable information about molecular mechanisms that can be utilized by computational methods to identify functional and phenotypic relatedness, improve our understanding of disease and pathobiology, and lead to discovery of drug targets. Identifying functions and phenotypes commonly requires experiments which are time-consuming and expensive to carry out; creating the annotations additionally requires a curator to make an assertion based on reported evidence. Support to validate the mutual consistency of functional and phenotype annotations as well as a computational method to predict phenotypes from function annotations, would greatly improve the utility of function annotations.

Results

We developed a novel ontology-based method to validate the mutual consistency of function and phenotype annotations. We apply our method to mouse and human annotations, and identify several inconsistencies that can be resolved to improve overall annotation quality. We also apply our method to the rule-based prediction of regulatory phenotypes from functions and demonstrate that we can predict these phenotypes with Fmax of up to 0.647.

Availability and implementation

https://github.com/bio-ontology-research-group/phenogocon
The Inverse Spectral Problem for Periodic Conservative Multi-peakon Solutions of the Camassa–Holm Equation
Authors: Eckhardt Jonathan , Kostenko Aleksey
Published: July 2018

We solve the inverse spectral problem associated with periodic conservative multi-peakon solutions of the Camassa–Holm equation. The corresponding isospectral sets can be identified with finite-dimensional tori.
The macroecology of passerine nest types, in the light of macroevolution
Authors: McEntee Jay P. , Zelazny Zoe , Burleigh J. Gordon
Published: July 2018

Passerine birds build a diversity of nests to lay and incubate eggs, and to house nestlings. Open cup, dome, and hole (or cavity) nests have distinct advantages and/or disadvantages related to predation risk and thermoregulation. We used macroecological and macroevolutionary approaches to test contrasting predictions from considering these consequences. Patterns of prevalence across latitude and elevation for the roofed nest types (holes and domes) provide no evidence that their thermoregulation benefits promote colonization of colder environments. These patterns are more consistent with the role of predation in determining where dome-nesting species in particular occur. Macroevolutionary analyses suggest that diversity patterns for nest types along major ecological gradients mostly arise from how clades with conserved nest types have diversified across gradients, rather than arising from local adaptation. Lastly, we reveal a negative relationship between body mass and latitude in hole-nesting passerines, which runs counter to Bergmann’s rule.

Statement of authorship

JPM and JGB designed the study. JPM and ZZ compiled data from the literature. JPM performed statistical analyses with input from JGB. JPM and JGB wrote the manuscript, and ZZ contributed to revisions.

Data accessibility statements

Data were obtained from existing sources in the literature, cited in the manuscript.