bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controlled-flow Instruments for Simulating in Vivo Thrombosis
Authors: Clark H. G , Shinoda B. A , Mason R. G 
Published: June 2018

SummaryA technique has been developed which allows an estimation of the clotting tendency of blood under conditions which simulate in vivo flow in various regions of the circulatory system. Minimum contact between blood and foreign surfaces other than the walls of the tubular test cell is obtained. Early pre-clotting and clotting events which alter the apparent viscosity of blood are resolved within three seconds of their onset. Increases in apparent viscosity slow the oscillations of the test system, and frequency, differential frequency, or amplitude can be monitored continuously. A standard tubing material may be used to evaluate effects of antithrombotic or other agents. For the present studies, the instrument was used with native blood at 28° or 37° C to produce shear rates comparable to those present in venous flow. Gum rubber, vinyl, glass and silicone tubing have been investigated for their effects on activation of the intrinsic coagulation system of human blood. In order of increasing-time to formation of thrombus are glass, vinyl, rubber, silicone. Thrombi were adherent to glass and rubber but not to Tygon or Silastic tubes. Time sequence studies during flow in silicone tube with native blood indicate progressive shortening of Stypven and partial thromboplastin time values, and progressive decrease in leukocyte and platelet counts. Addition of a commercial bovine collagen preparation to native normal blood in Silicone tubing decreased the thrombus time value by 40% while addition of the experimental agents RA 233 or VK 744 decreased this value by 50% and 70% respectively. Aspirin therapy produced a 158% increase in thrombus time values. Light microscopic studies of thrombi formed in this closed system revealed thrombus structure comparable to that of classic venous thrombi.
Effect of Corticosteroids upon Fibrinogen Metabolism in Rabbits
Authors: Seligsohn Uri , Rapaport Samuel I. , Shen Stephen M.-C. , Kuefler Paul R. 
Published: June 2018

SummaryThe effect of pharmacologic doses of adrenal corticosteroids upon plasma fibrinogen level, incorporation of 75Se-Methionine (75SeM) into fibrinogen, and disappearance of plasma 125I-fibrinogen was evaluated in rabbits. Single 25 mg doses of hydrocortisone or cortisone transiently increased both 75SeM incorporation into fibrinogen and plasma fibrinogen levels, but 1 to 5 mg doses of hydrocortisone had no significant effect upon plasma fibrinogen levels. Repeated daily injections of 25 mg of hydrocortisone did not increase plasma fibrinogen levels progressively. Two doses of 25 mg of hydrocortisone, given 24 hr apart, failed to alter the rate of disappearance of plasma 125I-fibrinogen radioactivity, i.e., plasma fibrinogen catabolism. Intramuscular injection of 2.5 ml of propylene glycol solvent caused a prolonged rise in plasma fibrinogen level, whereas injection of 25 mg of corticosterone dissolved in propylene glycol resulted in an attenuated and transient rise in plasma fibrinogen level. Apparently, the presence or absence of a coexistent inflammatory stimulus determines the overall effect of large pharmacologic doses of corticosteroids upon fibrinogen metabolism in the rabbit. In the presence of inflammation, corticosteroids decrease synthesis with a resultant fall in plasma fibrinogen level; in the absence of inflammation, corticosteroids may increase synthesis transiently with a resultant slight increase in plasma fibrinogen level.
Effect of Aspirin and Benadryl on Human Platelet Oxidative Phosphorylation and Aggregation
Authors: Yue Kenneth T. N. , Davis James W. , Aldridge E. Gray 
Published: June 2018

SummaryTightly coupled oxidative phosphorylation in washed human platelets and in lysates has been demonstrated. Both aspirin (25 μM) and Benadryl (0.15 mM) inhibited phosphorylating oxidation but had no effect on uncoupled respiration. It is likely that they were not involved in the electron transport chain but specifically affected the phosphorylation reactions similar to the action of oligomycin. Preincubation of Benadryl (1.3 mM) with platelet-rich plasma (PRP) at room temperature for 2 min inhibited ADP-induced platelet aggregation by 62% and abolished the second phase of aggregation. Addition of Benadryl to aggregating platelets in PRP during ADP-induced aggregation caused immediate disaggregation whether added during the first or second phase of aggregation. Aspirin had no such effect.
Technical Remarks on the Microscopical Demonstration of Tissue Plasminogen Activator
Authors: Pandolfi M , Bjernstad A , Nilsson Inga Marie 
Published: June 2018

SummaryThe authors examine some variables capable of influencing the results obtained with the fibrin slide technique for microscopical demonstration of fibrinolytic activators in tissues (Todd’s method).The speed of freezing of the tissue specimen proved to be especially important. Slow freezing of the specimen should be avoided since it results in sections of poor quality and may alter the distribution of fibrinolytic activity. The optimal thickness of the sections lies between 6 and 8 (jim. The concentration of fibrinogen used as substrate may vary between 0.7 and 2.0% and the thickness of the fibrin film between 0.07 and 0.21 mm. Increasing the temperature of incubation from +4° C to +37° C enhanced fibrinolysis, but had no effect on the distribution of fibrinolytic activity in the sections. Storage of the sections at —20° C and at +4° C for 6 days had no apparent effect on their fibrinolytic activity. Storage at 28° C resulted in a considerable loss of the fibrinolytic activity of the sections. The error of a method to assess the strength of fibrinolytic activity of the section is determined.
Gerinnungsphysiologische Analyse der Wirkung synthetischer Thrombininhibitoren
Authors: Maekwaedt F 
Published: June 2018

ZusammenfassungEs wurde der Einfluß von jeweils einem Vertreter aus der Gruppe der kompetitiv, der substratartig und der irreversibel wirkenden synthetischen Inhibitoren für Serinproteinasen auf den Ablauf der Blutgerinnung analysiert. Demnach läßt sich die Gerinnung nur von den kompetitiv wirkenden Inhibitoren aufhalten, deren Reaktionsgeschwindigkeit die der Ferment-Substrat-Reaktion erreicht. Ihre Wirkung kommt durch eine Hemmung des Gerinnungsfermentes Thrombin zustande, die sich nicht nur auf die Fibrinogenumwandlung beschränkt, sondern auch auf andere Wirkungen des Thrombins im Gerinnungssystem, wie die Auslösung der Plättchenaggregation und die Reaktion mit dem Antithrombin des Blutes, erstreckt.
Platelet Aggregation in Diabetes Mellitus and the Effect of Insulin in Vivo on Aggregation
Authors: Hassanein A. A , El-Garf Th. A , El-Baz Z 
Published: June 2018

SummaryADP-induced platelet aggregation and calcium-induced platelet aggregation tests were studied in 14 diabetic patients in the fasting state and half an hour after an intravenous injection of 0.1 unit insulin/kg body weight. Platelet disaggregation was significantly diminished as compared to a normal control group, and their results were negatively correlated with the corresponding serum cholesterol levels. Insulin caused significant diminution in the ADP-induced platelet aggregation as a result of rapid onset of aggregation and disaggregation. There was also a significant increase in platelet disaggregation. In the calcium-induced platelet aggregation test, there was a significant shortening of the aggregation time, its duration, and the clotting time. The optical density fall due to platelet aggregation showed a significant increase. Insulin may have a role in correcting platelet disaggregation possibly through improvement in the intracellular enzymatic activity.
Some Effects of Calcium and Strontium Ions on Three Basic Reactions of Blood Coagulation
Authors: Sakuragawa Nobuo , McCoy Lowell E. , Seegers Walter H. 
Published: June 2018

SummaryCalcium ions accelerated all three basic reactions of blood coagulation at an optimum concentration of 0.01 M. Strontium ions were practically ineffective as substitutes for calcium ions in the formation of autoprothrombin C (factor Xa), but functioned just as effectively as calcium ions in the formation of thrombin. Inhibition was the primary effect of strontium ions in fibrin formation. It is suggested that calcium ions function differently in each reaction. Echis carinatus venom was found to form thrombin directly from its precursor and, likewise, formed autoprothrombin C from its precursor.
Quantitative Monitoring of Intravascular Coagulation and Fibrinolysis in the Lungs of Rats
Authors: Coombey D , Tyler H. M 
Published: June 2018

SummaryA method is described whereby the arrival and subsequent lysis of thrombin- induced, 125I-labelled, pulmonary emboli can be quantitatively monitored in the rat. A scintillation probe placed over one lung monitors radioactivity in that organ ; serial counts or a continuous recording of radioactivity can be made. Radioactivity counted in serial blood samples also reflect the defibrination and fibrinolytic processes. The influence of the inhibitor EACA, and the lytic agent Brinase are described.
Glutaraldehyde Fixation of Human Blood Platelets
Authors: Sixma J. J , Linssen W. H , Geuze H. J 
Published: June 2018

SummaryHypertonic glutaraldehyde solutions produce dilatation of the surface connected system and shrinking of the cytoplasma. Hypertonic solutions produce swelling of the platelets. Good results are obtained with 1% glutaraldehyde M 0.07 M phosphate buffer (275 mosmol) 4 parts to 1 part platelet rich plasma. High glutaraldehyde concentrations do not affect the platelet ultrastructure.
The Effect of Alpha- and Beta-Receptor Blocking Agents on Collagen-Induced Platelet Release Reaction (A Comparison with ADP-Induced Release)
Authors: Kubisz P , Suranova J 
Published: June 2018

SummaryThe mechanism of the platelet release reaction, induced by collagen, is in certain respects different from that of ADP. Besides other facts, the PF 4 release and the availability of PF 3 and APh are not influenced by the concentrations of alpha or beta-receptor blocking agents which clearly interfere with the ADP-induced release.The possible role of thrombosthenin (or its alpha-receptors in the participation of the release reaction is discussed.
The Dual Sample Aggregometer
Authors: Gerloff J , von Kaulla K. N 
Published: June 2018

SummaryAn improved platelet aggregometer is described which permits the simultaneous recording of two aggregation curves obtained under technically strictly identical conditions which can be recorded with any single pen recorder. The curves are superimposed thus facilitating the visual or mathematical assessment of differences in the aggregation pattern. The instrument is particularly suitable for serial testing of aggregation inhibiting agents. It is equally suitable in the conventional way as any single channel aggregometer for routine testing of platelet aggregation.
Disseminated Intravascular Coagulation Induced by Liquoid in Normal, Thrombocytopenic and Granulocytopenic Rabbits
Authors: Skjørten F , Evensen Stein A. 
Published: June 2018

SummaryDisseminated intra vascular coagulation was induced by the synthetic acidic polymer Liquoid (sodium polyanethol sulfonate) in normal rabbits, in rabbits with a combined thrombocytopenia and granulocytopenia induced by busulphan, and in rabbits with a selective granulocytopenia induced by nitrogen mustard. One hour after the injection of Liquoid, light microscopy showed deposits with the staining properties of fibrin in glomerular capillaries and hepatic sinusoids of animals from all pretreatment groups. After 2 h, there was an increase in the deposits in all groups, most marked in rabbits with normal platelet and leukocyte counts prior to Liquoid injection.By electron microscopy, normal animals injected with Liquoid showed predominantly fibrillar deposits in glomerular and hepatic capillaries. The center of some of these deposits was composed of granular masses. Animals with combined thrombocytopenia and granulocytopenia, or with selective granulocytopenia showed purely granular deposits.We conclude that both types of deposits are derived from fibrinogen. The fibrillar material is assumed to be polymerized fibrin, whereas the granular material may possibly represent complexes formed between fibrin monomers and other plasma proteins, including fibrinogen precipitated by Liquoid.
Studies of the Metabolism and Distribution of Prothrombin in Healthy Men with Homologous 125I-Prothrombin
Authors: Takeda Y 
Published: June 2018

SummaryA method was described for preparation of purified human prothrombin using repeated barium citrate adsorption and citrate elution, (NH4)2S04 fractionation, Sephadex chromatography and isoelectric precipitation. The produced prothrombins were then physicochemically analyzed. The extinction coefficient was 12.7 ± 0.82 (SD) and the specific activity, 2,563 ± 420 (SD) Iowa units per mg prothrombin. The amino acid composition in g% was as follows: aspartic acid, 8.64; threonine, 5.87; serine, 4.16; glutamic acid, 11.15; proline, 3.91; glycine, 3.96; alanine, 4.65; half cystine, 4.68; valine, 4.46; methionine, 1.14; isoleucine, 2.93; leucine, 6.18; tyrosine, 4.52; phenylalanin, 4.19; lysine, 4.78; histidine, 1.73; ammonia, 1.85; arginine, 6.91. The tryptophan and carbohydrate contents were not determined. The prothrombins were then labeled with 125I in a ratio of about 0.25 atom iodine per molecule of prothrombin and were used for studies of the metabolism and distribution of prothrombin in thirteen healthy men. A model was proposed for the human prothrombin system based on the assumptions that prothrombin is catabolized intravascularly without the formation of thrombin, and was tested against the observed behavior of injected 125I- prothrombin. The model closely predicted the observed behavior of 125I-prothrombin. The analytical results of the tracer data in thirteen healthy men by the methods derived from the model were as follows: The plasma prothrombin, 6.65 ± 1.10 (SD) mg per kg; the interstitial prothrombin, 6.0 ^ 1.9 (SD) mg per kg; the half-life of plasma 125I-prothrombin, 2.29 ± 0.14 (SD) days ; the transcapillary transfer rate of prothrombin, 10.2 ± 3.9 (SD) mg per kg per day; and the catabolic (synthetic) rate of prothrombin, 4.3 J: 1.0 (SD) mg per kg per day. These results support the concept that in healthy men prothrombin is degraded in plasma or spaces in rapid exchange with it generation of appreciable amounts of thrombin.
The Effects of Bile Salts on Some Coagulation Components and Related Enzymes
Authors: Engel A. M , Alexander B 
Published: June 2018

SummaryCertain purified bile salts, individually or in a mixture, profoundly affect - either inhibiting or enhancing - the esterolytic activities of thrombin, trypsin, and plasmin, the clotting activity of thrombin, and caseinolysis by trypsin. They also promote SK-induced fibrinolysis and impair FI clottability. These effects are directly related to bile salt concentration but not to the critical micellar concentration.A very unusual effect was observed with deoxycholate and FI : besides inhibiting FI clottability, the salt induces spontaneous gelation. In addition, it binds strongly to the protein, as has been already reported for another plasma protein, albumin, and to a lesser degree, to alpha- and beta-globulins.Noteworthy is the fact that activation of pancreatic juice trypsinogen by thrombin also was increased by prior thrombin exposure to the salts. On the other hand, thrombin-induced platelet aggregation was slightly inhibited by the bile salt mixture, which, when added to PRP moderately inhibited the ADP-induced aggregation. No effect was observed on the conversion of F II in plasma via the thromboplastic mechanism when deoxycholate, or cholate, or glycocholate was added to the system.It is postulated that the bile salt mixture enhances SK-induced fibrinolysis by direct action, either on SK, or on the SK-activator complex, attributable to the detergent properties of the salts.The physiologic and pathologic implications of our results with respect to hemostasis and pancreatitis are discussed.
Identification of Fibrinogen Derivatives in Plasma Samples
Authors: Graeff H , von Hugo R 
Published: June 2018

SummaryThe observation of fibrinogen derivatives with a molecular weight higher than the parent molecule in human cases of DIC initiated the present methodological study. These derivatives were identified by the following methods : 2.5 M β-alanine precipitation of the plasma samples, PAA gel electrophoresis, intra gel immunoprecipitation and agarose gel chromatography. In the plasma of a patient with severe eclampsia and laboratory signs of DIC two derivatives with a molecular weight higher than that of fibrinogen were identified according to their relative electrophoretic mobilities: 0.18 and 0.28 × 10−5 cm2/V × sec (fibrinogen: 0.43 × 10−5 cm2/V × sec). Electrophoretic studies in the presence of 5 M urea indicated that the 0.28 derivative is a complex probably formed by fibrinogen and a fibrin monomer.
An Evaluation of Impedance Plethysmography and 125I-Fibrinogen Leg Scanning in Patients following Hip Surgery
Authors: Cruickshank M K , Levine M N , Hirsh J , Turpie A G G , Powers P , Jay R , Gent M 
Published: June 2018

SummaryVenous thromboembolism is a common post-operative complication in patients following hip surgery. 125I-fibrinogen leg scanning and impedance plethysmography (IPG), are often used in the detection of venous thrombi in such patients. Information on the sensitivity and specificity of these non-invasive tests for the diagnosis of venous thrombosis following hip surgery is relevant for both patient management and for choosing the appropriate outcome measure for clinical trials evaluating new prophylactic regimens.We determined the sensitivity and specificity of the IPG alone, the 125I-fibrinogen leg scan alone, as well as the combined use of the two tests from a retrospective analysis of 685 hip surgery patients who participated in clinical trials of anti-thrombotic prophylaxis. These patients were followed prospectively with non-invasive tests. Bilateral venography was attempted either when one or both screening tests became positive or on day 10-14 post-operatively if both screening tests remained negative. Adequate venography was obtained in 1,010 (73.7%) legs and thrombi were identified in 198 (19.6%) legs.The sensitivities of the IPG and leg scanning were 12.9% and 44.6% respectively; the corresponding specificities were 98.1% and 95.0%. The sensitivity of a positive result on one or both screening tests was 49.6% with a specificity of 93.9%.Therefore, leg scanning and IPG, even in combination, are not sufficiently accurate to be recommended as the only strategy for the diagnosis of venous thrombosis following hip surgery. Venography should be considered in all patients undergoing surveillance testing either when one or both of the screening tests become positive or on day 10-14 if the screening tests remain negative.
The Polymerization of Fibrin Prepared from Fibrinogen Haifa (γ275Arg→His)
Authors: Siebenlist Kevin R , Mosesson Michael W , Di Orio James P , Tavori Shulamith , Tatarsky lllana , Rimon Abraham 
Published: June 2018

SummaryFibrinogen Haifa is a congenital heterozygous fibinogen variant (γ275 Arg→His) characterized by prolonged thrombin and reptilase times and normal fibrinopeptide (FPA, FPB) release. We compared the polymerization rate (by turbidity measurements at 350 nm) and the ultrastructure of Haifa α-, β-, and α, β-fibrin with that of normal. Haifa α, β-fibrin polymerized less rapidly than did normal and formed a highly branched matrix with a smaller mean fiber diameter; this network closely resembled that of normal α, β-fibrin with EDTA added. In the presence of CaCl2 (1 to 10 mM), Haifa α, β-fibrin polymerized more rapidly than in buffer alone and possessed a matrix structure closely resembling that of normal fibrin. From these observations it appears that the functional defect in Haifa fibrin can be related to the inability of the abnormal molecule to effectively utilize available calcium. The polymerization profile of Haifa α-fibrin differed only modestly from that of normal α-fibrin, whereas that of Haifa β-fibrin was markedly impaired. This finding plus similarities in the ultrastructure of Haifa and normal α-fibrin specimens suggests that the defective γ chain structure of Haifa fibrinogen results in greater impairment of the carboxy terminal “b” polymerization domain reacting with the site exposed by cleavage of FPB (“B” site) than it does that of the carboxy terminal “a” domain reacting with the site exposed by cleavage of FPA (“A” site). Whether this effect is due to absolute differences in the degree of impairment of these two types of polymerization sites, or whether proper utilization of the “B” to “b” site is dependent upon participation of the “A” to “a” site remains to be determined.
Procoagulant Activity of T Lymphoblastoid Cells in Extrinsic and Intrinsic Coagulation Systems
Authors: Barrowcliffe T W , Marshall Dianne E , Trickett Lynne P , Hubbard A R , Gray Elaine , Thorpe R 
Published: June 2018

SummaryWe have measured the procoagulant activity (PCA) of four T lymphoblastoid cell lines (Jurkat, CEM, HSB-2 and Molt 4) as well as normal peripheral blood T lymphocytes, before and after stimulation with phytohaemagglutinin (PHA), using clotting and amidolytic methods.Of the four cell lines only one, Jurkat, gave enhanced PCA after stimulation with PH A. This activity was shown to be tissue factor-like by its dependence on factor VII in plasma and in an amidolytic assay with purified factors VII and X. Jurkat was also the only one of the four cell lines to secrete interleukin-2. All four cell lines promoted the generation of large amounts of thrombin in platelet-free plasma in glass tubes. This activity was dependent on the presence of plasma factor VIII, and was probably due to phospholipids in the cell membranes. Normal T lymphocytes gave intrinsic PCA in the thrombin generation test which was only 15% of that of the lymphoma cells.These results show that some T lymphocytes can develop PCA in both intrinsic and extrinsic systems and this should be taken into account in studies of the PCA of mixed leukocyte populations.
Distinguishing Plasma Lupus Anticoagulants from Anti-Factor Antibodies Using Hexagonal (II) Phase Phospholipids
Authors: Rauch Joyce , Tannenbaum Marion , Janoff Andrew S 
Published: June 2018

SummaryThe association of lupus anticoagulant antibodies with thrombosis, thrombocytopenia, and multiple spontaneous abortions underlines the importance of diagnostic assays which are able to distinguish these antibodies from anti-factor antibodies and factor deficiencies, as all three prolong in vitro coagulation assays measuring activated partial thromboplastin time (APTT). Heparin also prolongs the APTT assay and often interferes with the detection of lupus anticoagulant activity. The present study describes a direct and simple dilute APTT assay in which plasma is preincubated with hexagonal (II) phase phosphatidyl ethanolamine (PE). Using this system, the lupus anticoagulant antibody activity of 10 randomly selected plasmas from SLE patients was inhibited by 81.2-99.5%, while prolongation of the APTT assay by 6 different anti-factor antibody-containing plasmas, 5 factor deficient plasmas, and 6 heparin-containing plasmas remained unaffected. Inhibition was dependent on epitopes exposed when PE was presented in the hexagonal (II) phase. This data suggests that hexagonal (II) PE is specifically recognized by lupus anticoagulant antibodies in SLE patients and may play a role in the etiology of the disease.