bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in Platelet Aggregability after Ovariectomy
Authors: Yamazaki Hiroh , Motomiya Takeshi , Sonoda Minoru , Miyagawa Noboru 
Published: August 2018

SummaryChanges in platelets in 48 patients with uterine myoma before and after hysterectomy with and without ovariectomy were examined. Bilateral ovariectomy in 25 cases (ovariec-tomized group) and unilateral or non-ovariectomy in 23 cases (control group) were performed at the hysterectomy. Platelet count and an appearance rate of secondary aggregation decreased at one day after and increased at one week after the operation, similarly in both the ovariectomized and the control group. The appearance rate of secondary aggregation was reflected in an intensity of aggregation at 5 min after the addition of reagent to PRP. At one month after the operation, the appearance rate of secondary aggregation induced by 3 μM ADP showed a statistically significant decrease in comparison with the preoperation value (P <0.05) and the enhancement of 5-min aggregation was still observed in the control group, while ceased in the ovariectomized group. The difference between the two groups was significant (P < 0.05). There was almost no change in the speed and intensity of primary and secondary aggregation during the observation period. No significant differences in collagen-induced aggregation were noted between the two groups. The results suggest that ovarian hormones, mainly estrogen, facilitate platelet activation which is mediated by the so-called secondary aggregation.
“Dirty” Fiber - “Clean” Fiber: A Theory of the Organization of Fibrin from Fibrinogen
Authors: Branson Herman E 
Published: August 2018

SummaryA theory of fibrin formation is proposed in which gel fiber fabrication is coordinated by two distinct sets of complexing filaments emanating from spherical fibrinogen-derived structural subunits. The formulation is an attempt to correlate the previously reported ultramicroscopic negative-contrast images of fibrinogen and fibrin with a similar but unique spheroidal body observed during the organization of dysfibrin Seattle. This slow clotting dysfibrinogen manifested a predisposition to form aperiodic fibers when thrombic proteolysis and polymerization were curtailed by the progressively earlier application of an acid stain embedment reagent (uranyl acetate). The unstriated fibers were unevenly surrounded by the electron dense stain and manifested a “dirty” appearance. This “primordial” fiber was comprised of linear chains of (10 nm) complexed spheres with (15 nm) lateral filamentous projections. Fibrinogen Seattle consistently generated typically striated (26 nm), “clean”, or “mature” fiber gels when polymerization was allowed to proceed. The proposed role of these lateral filaments is to engage, align, and stabilize similar processes on globular subunits in adjacent linear chains of the “primordial” fiber. The behavior of the negative contrast reagent during the fibrinogen to fibrin conversion is assessed as a reflection of the distribution and orientation of polar residues. The“clean” or striated fiber is depicted as a highly fenestrated hollow cylinder with a hydrophilic interior. The model is fitted to ultrastructural studies on the progression of transamidation of fibrin by factor XIIIa.
A Simple Rapid Method for Isolating Soluble Fibrin Complexes from Fibrinogen by Treatment with Thrombin and t-AMCHA
Authors: Hayashi Shigeru , Yamada Kaneo 
Published: August 2018

SummaryUsing treatment with thrombin associated with trans-aminomethylcyclohexane carboxylic acid (t-AMCHA), a simple and rapid method for isolating soluble fibrin complexes (SFC) from fibrinogen in the plasma was developed. By this procedure, the recovery rates of SFC and early FDP (mainly X) increased according to the concentration of t-AMCHA, reaching a maximum at 286 mM t-AMCHA. On the other hand, the recovery rate of fibrinogen remained below 1.5% and that of late FDP was almost 100% at all concentrations of t- AMCHA. These results suggested that SFC and FDP could be isolated from fibrinogen by thrombin and t-AMCHA (286 mM) treatment. Moreover, it was possible to isolate SFC from FDP using gel filtration after treatment with thrombin and t-AMCHA. The SFC could be quantified by assay of the eluted fractions containing SFC by the staphylococcal clumping test.
Localization of Tissue Fibrinolysis in the Gastrointestinal Tract
Authors: Stenberg Björn , Risberg Bo , Bois Marc , Zettergren Lennart , Peterson Hans-Inge 
Published: August 2018

SummaryTissue fibrinolysis in the stomach and intestine of the rat was studied with a histochemical technique. After perfusion of blood vessels to reduce the influence of circulating plasminogen activator and inhibitor fibrinolysis was localized mainly to submucosal arteries and to the serosa of the gastrointestinal tract. This is opposite to previous observations, in which tissue fibrinolysis in the gastrointestinal tract was suggested to be mainly localized to veins. A method for semiquantitative analysis of tissue fibrinolysis in the rat stomach is described.
Tranexamic Acid and Gastric Fibrinolysis in the Rat
Authors: Stenberg Björn , Risberg Bo , Peterson Hans-Inge 
Published: August 2018

SummaryAn optimal inhibition of tissue fibrinolysis, studied by a histochemical fibrin slide technique in the rat stomach, was obtained by administration of tranexamic acid in a dose of 60 mg/100 g body weight. A significant fibrinolysis inhibition was found within 5 min, when tranexamic acid in this dose was given either intravenously or intragastrically. A prolonged duration of fibrinolysis inhibition was observed after intragastric administration. After 4 hr no inhibitory effect of tranexamic acid could be recorded, irrespective of the route of administration.
Changes in Platelet Functions, Coagulation and Fibrinolysis in Uncomplicated Cases of Acute Myocardial Infarction
Authors: Knudsen J Bjerre , Gormsen J , Skagen K , Amtorp O 
Published: August 2018

SummaryPlatelet aggregation and serotonin-release in vitro and some coagulation and fibrinolysis parameters were studied closely in 12 patients with non-complicated acute transmural myocardial infarction from the very beginning, for 3 weeks.The aggregability with ADP, epinephrine and collagen and the serotonin-release was significantly reduced the first days. Significantly increased aggregability and serotoninrelease developed after a week, with peak activity on days 14-16. Most patients still exhibited increased activity at the discharge on days 21-22.Positive ethanol gelation tests developed after day 1 in most patients with a peak at day 5, contemporary with peak activities of factor VIII and negatively correlated to factor XIII activity, quantitated biologically. These values were normalized on discharge. Antithrombin III (Xa) remained unchanged, normal to slightly elevated.The fibrinolytic activity decreased after day 1 with lowest activity on day 5, contemporary with peak activity of antiplasmin. Around 50% of the patients showed decreased activity on discharge.
Acquired von Willebrand’s Syndrome during Autoimmune Disorder
Authors: Pizzuto Javier , Ambriz Raul , de la Paz Reyna Maria , Monrroy Luis M , Morales Manuel R , Aviles Agustin , Conte Guillermo , Enriquez Ruben 
Published: August 2018

SummaryA case with evidence of acquired von Willebrand’s syndrome associated with systemic lupus erythmatosus and Sjögren’s syndrome is described. The patient, who had no family history of bleeding, presented a haemorrhagic diathesis of recent origin, the bleeding time was prolonged, procoagulant Factor-VIII and von Willebrand factor levels were low and platelet aggregation was decreased with different concentrations of Ristocetin®.No improvement was seen after the tranfusion of cryoprecipitates, and there was no increase in procoagulant Factor-VIII.Clinical improvement resulted after treatment with corticosteroids, and later, the laboratory abnormalities characteristic of von Willebrand’s disease became normal. The level of procoagulant factor-VIII reached the very high level of 810%.
The Turnover in Normal Dogs of Prothrombin and Its Fragments; Effect of Induced Intravascular Coagulation
Authors: Owen Charles A , Mann Kenneth G , McDuffie Frederic C 
Published: August 2018

SummaryWhen 125I-labeled canine prothrombin was given to normal adult dogs intravenously, it was calculated that 240% of the plasma prothrombin crossed the capillary barrier per day, 410% of the interstitial prothrombin returned to the blood stream daily, and 79% of the plasmatic prothrombin was catabolized per day. These data are in close agreement with those observed for bovine prothrombin in calves by Takeda (1970).When derived from normal dog prothrombin, prethrombin-1 is a mixture of 2 polypeptides, one larger than the other, and both present in about equal amounts. The longer peptide, “prethrombin-1-long,” was catabolized twice as fast as prothrombin, and the shorter, “prethrombin-1-short,” 4 times faster. Prothrombin fragment-1 was catabolized by the normal dog still more rapidly.The catabolism of prothrombin was not accelerated in 3 dogs receiving continuous infusions of a thromboplastic emulsion of dog brain. Nor was the level of prothrombin in their plasma remarkably altered.
The Plasminogen Content of Commercial Preparations and of Normal Donor Plasma in Relation to the Plasmin Content ot the 1st International Plasmin Reference Preparation
Authors: Wolf Peter 
Published: August 2018

SummaryKabi human plasminogen and plasmin and two Behringwerke preparations of human plasminogen were examined for antigen content, purity and specific activity with the 1st International W.H.O. human plasmin reference preparation and with the plasminogen content of an 8 donor normal plasma pool. In relation to the plasminogen content of the preparation with the highest specific activity, the 8 donor plasma pool contained 0.186 mg/ ml of plasminogen. This plasminogen on complete conversion to plasmin by streptokinase or urokinase corresponded to 4.35 International units/ml of plasmin as defined by the International reference preparation.Protein adsorption from highly purified plasminogens of low protein content induced variable underestimates of antigen and of biological activity. To prevent this it is recommended to issue these purified preparations in an inert carrier medium or alternatively to release these preparations with data pertaining to salt content and optical measurement prior to lyophilisation. When standards of high purity and low protein content are being examined for antigen and enzyme, it is recommended likewise that an inert protein carrier should be present in the diluent. Measurement of proactivator was considered to be unsuitable in reference to proactivator content of highly purified plasmin and plasminogen.
Potentiating Effect of Adrenaline on Adenosine Diphosphate - Induced Reduction in Rabbit Circulating Platelet Count: Inhibition by Dihydroergotoxine
Authors: Holmes Ian B 
Published: August 2018

SummaryThe number of circulating platelets was monitored in anaesthetized rabbits by a contiuous flow technique, using a Technicon Autocounter®. Transient reductions in circulating platelet count induced by a submaximal dose of adenosine diphosphate (ADP) were potentiated by concomitant infusion of adrenaline at doses (1-25 μg/kg i.v.) which did not influence platelet count when infused alone. The adrenaline effect was dose-dependent. Repeated infusions of adrenaline at 15 min intervals resulted in reproducible reductions in circulating platelet count during an observation period of at least 105 min.Dihydroergotoxine (DHET), administered either i.v. (2.5 - 10 μg/kg) or intraduodenally (i.d.; 25 - 100 μg/kg), inhibited adrenaline-induced potentiation dose-dependently; ADP- induced effects were not influenced. Duration of action was relatively long, and significant inhibitory activity was still apparent 50 (i.v.) and 115 (i.d.) min after drug administration.DHET doses inhibiting adrenaline-induced potentiation of platelet aggregation in the rabbit are similar to doses used in the treatment of impaired human cerebral function. It is conceivable that DHET could prevent activitation of human platelets by catecholamines released into the blood stream in clinical stress situations.
Differential Contribution of Oxidative and Glycolytic Energy to Thrombin-Induced Platelet Functions
Authors: Kobayashi Bonro , Watanabe Yasuko , Takasugi Naoyuki , Kurita Makiko 
Published: August 2018

SummaryWhen washed rabbit-blood platelets were preincubated in an artificial medium in the absence of external substrates, they aggregated in response to a low concentration of thrombin. The aggregation was completely inhibited after the preincubation with respiratory inhibitors. When glucose together with the respiratory inhibitors was added during the incubation, the aggregation was accelerated, whilst it was counteracted when Krebs-cycle substrates were added.ATP was generated actively during the incubation in the absence of external substrates, as well as in the presence of succinate. The ATP-generation was extremely inhibited by oligomycin. When glucose was added during the incubation with the respiratory inhibitor, the comparable amount of ATP with those in the oxidative systems was generated. Metabolic ADP was accumulated in the oxidative systems, particularly in the presence of succinate, in contrast to its low level in the glucose + oligomycin system. The results suggest that the counteraction of the aggregation by the Krebs-cycle substrate is attributed to the low adenylate energy charge. It is suggested that anaerobic glycolysis creates favorable energy condition for aggregation as compared with oxidative phosphorylation, although the washed platelets can be energized to a level above threshold of the aggregation when either one of the two energy generating systems is exerted.After the incubation of the platelets in the presence of thrombin, a higher level of metabolic ATP was observed under glycolytic condition, than under oxidative condition. Pulse-labelling experiments showed that ADP produced during the aggregation was rephosphorylated in a later part of the incubation in the glucose + KCN-fortified system. In the succinate-fortified system, the re-phosphorylation was very slow. The results suggest that oxidative phosphorylation is reduced in platelet aggregates treated with thrombin.
Platelet Adhesiveness to Glass
Authors: Page R L , Mitchell J R A 
Published: August 2018

Summary1. When anticoagulated blood is placed in a rotating glass flask, the blood/air interface initiates platelet aggregation, and the aggregates are trapped on the flask wall, without adhering to it, by the thin film of blood which forms during rotation. The interface; allows CO2 loss so that the pH of the rotating blood rises markedly and this rise is associated with the release of 3H-5HT from platelet. When CO2 diffusion and consequent pH rise is prevented, platelet loss and 3H-HT release are significantly reduced.2. A simple method for assessing the adhesiveness of single platelets to glass using a Neubauer haemocytometer chamber has been developed. The results obtained are independent of platelet number which allows the test to be used in conditions in which abnormal platelet behaviour is associated with a low platelet-count.3. Adhesiveness was negligible in heparinised PRP, and was greater in EDTA PRP than in citrated PRP. Heparin abolished the increased adhesiveness observed with the other anticoagulants and adhesiveness did not seem to be directly related to residual plasma calcium concentrations. Platelets adhered more readily to siliconised glass surfaces than to untreated glass, and adhesion was markedly temperature-dependent, being maximal at 4°C in heparinised PRP, and at 20° C in EDTA PRP.4. Adhesiveness was enhanced by aggregating agents, this enhancement being prevented by inhibitors of aggregation such as the dipyridamole analogue VK 774. Adhesiveness was unaffected by acetyl-salicylic acid.5. Adhesiveness increased markedly after surgical operations and myocardial infarction. Within-person variation was considerable, and the test is of no value in individual patients.
Coagulation in the Sand Crab (Ovalipes Bipustulatus)
Authors: Madaras F , Parkin J D , Castaldi P A 
Published: August 2018

SummaryThe coagulation mechanism of the sand crab (O. bipnsulatus) has been investigated. From the coagulocytes (amoebocytes) present in the crab haemolymph (blood), fibrinogen (coagulogen) was isolated. It was shown to be homogeneous by electrophoresis on S.D.S. polyacrylamide gel and had a molecular weight similar to the A α-chain of human fibrinogen. Unlike human fibrinogen it cannot be dissociated by reduction. In fibrin polymerization, a crosslinking process takes place and this process was inhibited by glycine ethyl ester. A fibrin stabilizing factor is present in the crab haemolymph and this protein was able to cross-link human fibrin in the same manner as human factor XIII.
Inactivation of Factor VIII by a Mechanism Independent of the Generation of Thrombin
Authors: Triantaphyllopoulos D C 
Published: August 2018

SummaryThrombin first activates and then inactivates factor VIII and for this reason thrombin has been considered responsible for the inactivation of factor VIII which occurs during clotting. Experiments described in this paper indicated that the activity of factor VIII is not reduced in factor IX or factor X deficient sera, while on the other hand this factor becomes inactivated in blood anticoagulated with high concentrations of hirudin which inhibit thrombin activity completely. This suggests that some other factor, besides thrombin, which is generated only in trace amounts in factor IX or factor X deficient plasmas, is also able to inactivate factor VIII. Purified factor X activated with insolubilized trypsin was added to purified preparations of factor VIII, which were free of both fibrinogen and prothrombin. Factor Xa was allowed to act for 5-60 minutes and then inactivated with phenylmethanesul- fonyl fluoride. Depending on the duration of the action of factor X a partial or complete inactivation of factor VIII was observed. This inactivation was also observed in the presence of hirudin, thus excluding the possibility that the effect was due to contamination with trace amounts of thrombin.
Studies on Metabolism of Urokinase and Mechanism of Thrombolysis by Urokinase
Authors: Ueno Tatsuo , Kobayashi Norio , Maekawa Tadashi 
Published: August 2018

SummaryPharmacokinetics of intravenously injected 125I-labeled urokinase (125I-UK) of a molecular weight of 33,000 daltons in normal rabbits and patients with various diseases were investigated. The plasma clearance of 125I-UK in rabbits was described by a biexponential curve within six hours with a half-life of 8 minutes, 2.3 hours, respectively. The radioactivity in the liver and kidneys 15 minutes after iv injection with 125I-UK was 9.6% and 14.0% of the radioactivity injected, respectively. Approximately 80% of the total radioactive material injected was excreted in the urine in 18 hours. No increase in activator activity in the urine was observed after a large amount of UK injection. Activity uptake of 125I-UK by experimentally induced arterial thrombus was little. Lysis of the stasis thrombus was produced by injecting 7.5 × 104 IU of UK in only one out of 8 rabbits. In vitro contact experiment revealed that transfer of 125I-UK to plasma clot is slow (24 hours for 10% of 125I-UK by plasma clot). In 4 patients plasma clearance of 125I-UK was essentially similar to that in rabbits. From the results obtained optimal dosage regimen of UK administration for complete thrombolysis in vivo was discussed.
Plasminogen Activator (Urokinase) from Cultured Cells
Authors: Lewis L James 
Published: August 2018

SummarySecretion of large quantities of urokinase by cultured renal cells suggested tissue culture as a means of production to meet demand for the material and to obtain guidelines for optimization of production. Rates of secretion and overall yields of urokinase from confluent cultures of renal cells have been studied in relation to species differences, effects of passage of cells, inoculum density, and volume of maintenance media. Aided in part by an advantage gained through addition of glycine to maintenance media, it is now possible to harvest urokinase at concentrations of the order of 800 CTA units per ml. Such concentrations are of the order of 102 times that occurring in human male urine.
Influence of Coagulation on the Activation of Plasminogen by Streptokinase and Urokinase
Authors: Takada Akikazu , Urano Tetsumei , Takada Yumiko 
Published: August 2018

SummaryHuman plasma was mixed with Ca++ or thrombin, and urokinase (UK) or streptokinase (SK) and a chromogenic substrate (S-2251: H-D-Val-Leu-Lys-pNA) specific to plasmin. The hydrolysis of S-2251 was higher when clot was formed by the addition of Ca++ or thrombin than in the absence of clot. The hydrolysis of S-2251 by euglobulin in the presence of UK was also higher when clot was formed, thus, inhibitors may not be related to the better activation of plasminogen, in the presence of fibrin clot. It may be suggested that plasminogen was better activated by activators (UK and SK) in the clot than in its absence.
Turning psychology into policy: a case of square pegs and round holes?
Authors: Walker Carl , Speed Ewen , Taggart Danny 
Published: August 2018

AbstractThis paper problematizes the ways in which the policy process is conceived in published psychological research. It argues that these conceptions of the policy process fail to adequately reflect the real-world dynamism and complexity of the processes and practices of social policy-making and implementation. In this context, psychological evidence needs to be seen as one type of evidence (amongst many others). In turn this requires researchers to take account of broader political processes that favour certain types of knowledge and disparage others. Rather than be regarded as objective and scientific, policy in this characterisation is regarded as a motivated form of politics. This multi-layered, multi-level hybrid structure is not immediately amenable to the well-intentioned interventions of psychologists. While the tendency of many psychologists is to overestimate the impact that we can have upon policy formation and implementation, there are examples where psychological theory and research has fed directly into UK policy developments in recent years. This paper draws on the recent Improving Access to Psychological Therapies (IAPT) initiative and the work of personality researcher Adam Perkins on the UK’s social security system to ask whether psychology has a sufficiently elaborated sense of its own evidence base to legitimately seek to influence key national areas of public policy. The article cautions against dramatic changes to policy predicated upon any one reading of the variegated and, at times, contradictory psychological evidence base. It concludes that, in order to meaningfully contribute to the policy development process in a way which increases equality and social justice, psychologists need to be more strategic in thinking about how their research is likely to be represented and misrepresented in any particular context. Finally some possible directions for psychologists to take for a more meaningful relationship with policy are suggested.