bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Mechanism of Action of α2-Antiplasmin
Authors: Wiman B. , Lijnen R. , Collen D.
Published: May 2019

The reaction between plasmin and α2-antiplasmin has been studied. The stoichiometric 1:1 complex between the enzyme and the inhibitor is formed in a rapid reaction during concomitant release of a non-disulfide bonded 8000 M2-peptide. The complex is very stable but can be dissociated in diluted NH4OH regenerating plasmin activity. The inhibitor-moiety obtained in this way has lost a peptide from its COOH-terminal part by cleavage of a Leu-Met peptide bond. From the data obtained and in analogy with trypsin-trypsin inhibitor complexes it is suggested that plasmin attacks a specific Leu-Met bond in the COOH-terminal portion of the inhibitor. A covalent bond is probably formed between the active site seryl residue in plasmin and the carbonyl group of the specific leucyl residue in α2-antiplasmin. Kinetically the extremely high reaction rate between plasmin and α2-antiplasmin is dependent upon an interaction of the inhibitor with one of the lysine-binding sites in plasmin. The latter structure is also in part responsible for the interaction between plasminogen and fibrinogen. Fibrinogen inhibits the reaction between plasmin and α2-antiplasmin in a competitive way suggesting that plasmin involved in fibrin(ogen) degradation is protected against α2-antiplasmin. This partly explains the selective action of plasmin in vivo.
Modifications of α2-Plasmin Inhibitor During Treatments by a Defibrinating Agent
Authors: Samama M. , Conard J. , Cazenave B. , Derlon A. , Gaudric A. , Coscas G.
Published: May 2019

A defibrination agent (Defibrase®) has been administered to 8 patients with retinal vein occlusion. Defibrase has been infused sub-cutaneously at a dose of 0.5 B. U./kg/day for 5 days followed by 1 to 2 B.U./kg twice a week, for 2 other weeks, so that fibrinogen level was maintained below 100 mg/100 ml. The tests performed were the following : fibrinogen, FDP, soluble complexes, plasminogen, α2 macroglobulin, antithrombin III, α2-plasmin inhibitor (amidolytic and Laurell methods), blood and plasma viscosity. They have been done before treatment and repeated daily for 5 days and then on the 8th, 11th, 14th and 21st day.

A decrease in fibrinogen, viscosity, plasminogen and an increase in FDP and soluble complexes have been observed, as already described. The results of the α2- plasmin inhibitor shows a decrease of about 50 % that is slightly more pronounced by the Laurell method than the amidolytic method. The plasmin-α2 plasmin inhibitor complex detected by crossed immunoelectrophoresis is present in various amounts.
Fibrinolysis Inhibition After a Standardized Trauma, Total Hip Replacement Surgery
Authors: Bagge L. , Carlin G. , Hjelmstedt Å. , Högstorp H. , Jakobsson H. , Modig J. , Saldeen T.
Published: May 2019

Inhibition of the fibrinolytic system with delayed elimination of fibrin from the lungs after trauma is probably an important factor in the pathogenesis of the delayed microem-bolism syndrome. In the present investigation the posttraumatic inhibition of the fibrinolytic system was studied in 20 patients. Lowered levels of plasminogen and plasminogen activators in the blood as well as a decreased response to the venous occlusion test were found after trauma. The most impressive finding was a heavily increased fibrinolysis inhibition activity (FIA) measured by a clot lysis assay with a maximum 3 days after traum in plasminogen depleted serum. After gel filtration of these sera on Sephadex G-25 the protein-fractions showed a loss of FIA but the same posttraumatic increase as in whole serum. Antibodies against the primary fibrinolysis inhibitor (PFI) (“α2-antinlasmin”) strongly reduced the FIA in posttraumatic serum. A good correlation was seen between the increase of PFI with affinity to plasminogen (PFI:α) and FIA whereas PFI:β (with lower of no affinity to plasminogen) showed a weak correlation to the posttraumatic FIA increase. The strong FIA of the fraction adsorbed to the plasminogen was apparently due to PFI:α and not to α2-macroglobulin or α1-antitrypsin. This investigation showed that PFI:α seem to be of major importance for the posttraumatic increase in FIA.
An Objective Trial of Alternative Methods of Heparin Administration
Authors: Bentley P.G. , Ward V.P. , Kakkar V.V.
Published: May 2019

Although it ts generally agreed that heparin is truly a life saving drug, the best method of administration remains to be determined. 100 patients with calf vein thrombosis were randomly allocated to receive either subcutaneous (SC) or intravenous (IV) heparin for seven days. Venography was performed in each patient to confirm the exact size and site of thrombus and was repeated at the end of heparin treatment. IV heparin was administered using a constant infusion pump. Platelet count, haemoglobin and haematocrit estimations were performed at the beginning, mid point, and end of hep rin treatment. The dose of heparin to be administered was determined by dally estimation of KCCT. In SC group, thrombi increased in size in 2%. remained unchanged in 50% and decreased in 48%. In IV group, they increased in size in 20%, were unchanged in 62% and decreased in 18%. The difference in decreases in size was significant (P < 0.01). Pre-treatment lung scans corfirmed the presence of emboli in 10 patients in SC and 11 in IV group; post treatmel scan showed improvement in 60% in SC compared to 91% in IV group. The mean daily heparin requirement (±SD) was 36,998 ± 7. 12IU in the SC group and 36,814 ± 6.63 IU in the IV group. The average KCCT fluctuation index in the SC group was 59.08 seconds compared to 64.4 seconds in the IV group. Major bleeding complications occurred in 2 patients on SC heparin and in 4 treated with IV heprin. The clinical signficance of these will be discussed
Seperation of Man’s and Rabbit’s megakaryocytes populations from sternal bone marrow
Authors: Dupont H. , Dupont M.A. , Lorient F. , Boisseau M. , Bricaud H.
Published: May 2019

In order to assess the role of the megakaryocytes disturbance in several pathological thrombotic situations, we designed a technic for concentration and seperation of megakaryocyte population from bone marrow.

Humann bone marrow megakaryocyte were isolated from sternal punction by two consecutive gradiebts of isosmoler Bovine serum albumine (B.S.A) solution in HANKS without Ca++ and Mg++ (Ph = 7.4) and density from 1.0024 to 1.0087 gm/ml at 1 g. Starting with Suspensions of bone marrow cells containing only 0.04% megakaryocyte, the proportion of megakaryocytes was enriched 50 times.

Five populations of Rabbit megakaryocyte were separated by B.S.A. density gradient centrifugation from 1,050 to 1.098 gm/ml at 100 g dating 20 mn. The cytophotometric evaluation of megakaryocyte ploidy degree required a novel separation according to the megakaryocyte size by velocity sedimentation in B.S.A. gradient at 1 g. By these technics, the proportion of megacaryocyte was enriched 60 to 100 times in each homogenous class. Then, qualitative and quantitative study were realized by cytopkotametric evaluation of DNA-Feulgen at 560 nm and residues ariginyls and lysyls in histones at 370 and 592 nm and correlated with ultrastructural features. Thus modifications of megakaryocytopoiesis in atherosclerotic coronary disorder in Man and experimental atherosclerosis in rabbit were recognized.

Supported by D.G.R.S.T. Grant 77.7. 1406
Role of Erythropoietin in Megakaryocyte Colony Formation in Man
Authors: Vainehenker W. , Breton-Gorius J.
Published: May 2019

We have recently realized megakaryocyte (MK) colony formation in culture from blood and bone marrow progenitors using the plasma clot technique. In this study, the MK stimulating factor was an erythropoietin (Epo) either a poorly purified one(step III from anaemic sheep serum, a crude serum from anaemic mice, an urinary human Epo) or a highly purified one (GOLDWASSER). Similar results were obtained with all these Epo. A linear relationship was found between the number of colonies and seeded cells. However with less than 5.105 plated cells from the blood, no MK colonies were obtained, although erythroid colonies could be grown. In contrast, without Epo, spontaneous colonies could be observed which represented 1/5 th of the maximum plating efficiency , in these eases no erythroid colonies were present. These data suggest that Epo itself acts an a MK colony stimulating factor; but is not the only factor involved in the formation of MK colonies. This in vitro technique will be useful of in determining the factors regulating megakaryocytopoiesis.
Simultaneous Frame-assisted Stereotactic Placement of Subdural Grid Electrodes and Intracerebral Depth Electrodes
Authors: Reinacher Peter C. , Altenmüller Dirk-Matthias , Krüger Marie T. , Schulze-Bonhage Andreas , Urbach Horst , Trippel Michael , Coenen Volker A. , Delev Daniel
Published: May 2019

Background and Study Aims In complex cases of drug-resistant focal epilepsy, the precise localization of the epileptogenic zone requires simultaneous implantation of depth and subdural grid electrodes. This study describes a new simple frame-assisted method that facilitates the simultaneous placement of both types of intracranial electrodes.

Material and Methods Ten consecutive patients were evaluated and divided into two groups. Group A included patients with simultaneous frame-assisted placement of depth and subdural grid electrodes. In group B, depth electrodes were implanted stereotactically; grid electrodes were implanted in a separate surgery.

Results The placement of the subdural grid was accurate as individually designed by the epileptologists in all five patients from group A. In group B, one patient showed a slight and another one a significant deviation of the subdural grid position postoperatively. The mean surgical time in group A was shorter (280±62 minutes) compared with the mean duration of the surgical procedures in group B (336±51 minutes).

Conclusion The frame-assisted placement of subdural grid electrodes facilitates the surgical procedure for invasive video-electroencephalography monitoring in complex cases of drug-resistant focal epilepsy in which a combination of depth electrodes and subdural grid electrodes is needed, by reducing the surgical time and guaranteeing highly accurate electrode localizations.
Sulphinpyrazone Reduces Deposition of Fibrin on Dialyser Membranes
Authors: Woods H.F. , Ash Gillian , WESTON M.J.
Published: May 2019

Activation of platelets may be responsible for thrombus deposition on dialyser membranes during haemodialysis despite adequate anticoagulation with heparin. This thrombus deposition increases residual blood loss within the dialyser and may impair dialyser efficiency thus limiting the reuse of disposable dialysers. To determine whether the antiplatelet agent sulphinpyrazone reduces such thrombus deposition dialyser 131I-fibrinogen and platelet fibrinogen levels during dialysis were compared in thirteen pairs of dialyses in five patients during a nontreatment control period and while the patients were receiving sulphinpyrazone 200 mg tds. The mean fibrin deposition within the dialysers measured as gram x10-3 of clottable fibrinogen was significantly less during the treatment period (2.5) than during the control period (5.3).Sulphinpyrazone reduced the fall in platelet count during dialysis. Plasma fibrinogen levels during haemodialysis were significantly higher with sulphinpyrazone treatment compared to control dialyses and this difference could not be explained solely by reduction of fibrin deposition on the dialyser membranes. It is probable that sulphinpyrazone reduces fibrinogen consumption within the patient during dialysis as well as within the dialyser membrane itself.
In Vivo Detection of Platelet Deposition in Coronary Artery Bypass Grafts in Dogs and Its Prevention with Platelet-Inhibitors
Authors: Fuster V. , Chesebro J.H. , Dewanjee M.K. , Kaye M.P. , Josa M. , Byrne J.W.
Published: May 2019

At 8 and 32 hours after saphenous vein bypass graft surgery in 7 dogs, in vivo images of the graft were obtained with a gamma camera after I.V. injection, 2 hours postoperatively of autologous 111In-Iabelled platelets. Platelet deposition in the grafts could be imaged from the scintiphotos. Under identical conditions, in 9 dogs treated with Dipyridamole (2.5 mgs/kg/day) plus Aspirin (15 mgs/kg/day) (D + ASA), the grafts had significantly less platelet deposition as estimated by imaging (P <0.01). The in vitro radioactivity ratios (mean ± S.E.) of isolated graft sections to nontarget tissues of control and treated animals are as follows:

This noninvasive technique may be a promising tool for a better understanding of the role played by platelets in the process of occlusion of saphenous vein bypass grafts in man and its prevention with platelet inhibitors.
Experimental Atherosclerosis: Surface Ultrastructural Studies in the Rabbit Aorta
Authors: Rodman N.F. , Jagannathan S.N. , Jenkins J.J. , Rodman J.A.
Published: May 2019

Numerous techniques have been employed in the study of experimental atherosclerosis. This study employs critical point drying, cryofracture and transmission and and scanning electron microscopic studies of experimental atherosclerosis in New Zealand white rabbits. Rabbits were maintained on a diet containing 1% cholesterol and 5% Wesson oil and had serum cholesterol levels of 1800 to 2100 mg/dl. Animals were sacrificed at 100 days, 181 days, 217 days, 225 days and 246 days after starting the atherogenic diet. Animals were fixed by perfusion, using Tyrode’s solution followed by Trump’s fixative. Most severe lesions were in the ascending aorta. Least severe lesions were in the common iliac arteries. Very early lesions had widened intimal spaces containing free lipid and smooth muscle cells containing lipid vacuoles. These lesions had distinct borders or were irregular and diffuse. More severe lesions had micro-ulcers at irregular borders. Endothelium over the surface of such lesions was variable and usually intact. An occasional cell with microvilli was observed. By cryofracture cells contained lipid vacuoles with multiple intercommunications. In later lesions cholesterol clefts were also seen. Lipid vacuoles were also observed 1n endothelial cells and in smooth muscle cells of the superficial media. It seems reasonable to conclude that lipid is transported into the subendothelial intimal space and there taken up by smooth muscle cells.
Immuno-Electronmicposcopical Localisation of Fibrinogen And Factor VIII-VWF in Cryostat Ultrathin Sections of Human Blood Platelets.
Authors: Sander H.J. , Slot J.W. , Bouma B.N. , Geuze J.J. , Sixma J.J.
Published: May 2019

Blood platelets fixed in a mixture of 2% paraformaldehyde and 0-0.2% glutaraldehyde in phosphate buffered saline were soaked in 1M sucrose and frozen in liquid nitrogen. Ultra-thin cryostat sections obtained at -70°C were incubated with immunoadsorbed rabbit IgG anti-fibrinogen and anti VIII-VWF. Goatantirabbit IgG conjugated to ferritin was utilized as second layer. The fixation techniques did not allow us to identify dense bodies. Fibrinogen was localized on the cell surface and in invaginations of the platelet and on nearly all granules. In washed platelets fibrinogen was present on the granules but not on the cell surface, or in invaginations. VIII-VWF was only demostrable in samples fixed in 0.2% paraformaldehyde or acetone. The ultrastructure of these samples was poor but results indicating a localization in granules were obtained. Studies with TRITC-labeled goat-anti-rabbit IgG indicate a similar localization for fibrinogen and VIII-VWF. Double labelexperiments are currently in progress.
Decrease in Platelet Adenine Nucleotides Content In Patients With Dic, Thrombosis and After Operation
Authors: Yamazaki H. , Motomiya T. , Miyagawa N. , Watanabe C. , Yahara Y. , Okawa Y. , Onozawa Y.
Published: May 2019

Conditions which induce platelet release reaction in vivo are not yet obvious. To detect the conditions, platelet ATP and ADP content (firefly luciferase method) and plasma beta-thromboglobulin level were measured in 51 healthy young volunteers, 10 patients with typical DIC syndrome during time course of cancer, 27 patients in acute stage of thrombosis in cerebral, coronary and femoral arteries, 29 patients in recovery stage of thrombosis and 69 patients one day before, and one day, one week and one month after a laparotomy. Platelet count and volume were counted by a Coulter Counter and Channelyzer. Platelet aggregation induced by ADP, adrenaline and collagen was also measured. In the healthy, platelet mode volume was 4.21 ± 0.08 μ3 (mean ± SE). beta-TG was 29.9 ± 5.9 ng/ml, and ATP and ADP contents were 5.81 ± 0.17 and 3.19 ± 0.09 μmoles/1011 platelets and ATP/ADP was 1.82 ± 0.05. In DIC, acute stage of thrombosis and one week after laparotomy, platelet volume became to smaller and ADP content decreased significantly. Changes in beta-TG level were rather variable. Platelet aggregation increased in thrombosis and postoperative state, while it decreased in DIC. In DIC, decrease in ATP and ADP content was marked as compared with other groups. It suggests that ADP content In platelets may reflect release reaction in vivo. Following the release reaction, platelet aggregability may increase. However, platelets with large decrease in adenine nucleotides content may have hypofunction.
Activation of Factor VIII by Thrombin as Measured by Competition Kinetics
Authors: Sandberg H. , Brodén K. , Andersson L.-O.
Published: May 2019

It is known that the procoagulant activity of purified Factor VIII is strongly increased when incubated with concentrations of thrombin below 0.1 unit/ml. It has been assumed that this also is a mechanism of physiological importance thus that activation of Factor VIII by low concentrations of thrombin is one step in normal blood coagulation. The rate constant tor the reaction between Factor VIII and thrombin was estimated by two different methods. In one method formation of “activated” Factor VIII in a system containing thrombin, purified Factor VIII and albumin added as stabilizer was measured. In the other method the competition of purified Factor VIII as substrate for thrombin was compared with fibrinogen and a chromogenic peptide substrate. As expected it was found that thrombin had higher affinity for Factor VIII than for fibrinogen. The values calculated for the second order rate constant, using 240,000 as the molecular weight of the reactive unit in Factor VIII, were similar for the various systems, around 106s-1M-1.
Isolation and Characteristics of High-Activity Heparin
Authors: Danishefsky Isidore , Radoff Steven , Bender Michael , Villanueva German
Published: May 2019

Chromatography of heparin from beef lung on Biogel P-100 yielded a series of fractions with different anticoagulant activities. The assays for activity of the products were based on their effect in accelerating the inhibition of thrombin by antithrombin. Residual thrombin was measured by its effect on the clotting of fibrinogen and by its action on the chromogenic substrate H-D-Phe-Pip-Arg-p-nitroanilide (S-2238). Fractions with as much as 6-10 times the clotting activity of the original heparin, were obtained. The activities per mg of heparin were highest in fractions eluted in, or near, the void volume of the column. In addition to glucosamine and uronlc acid, the most active fractions contained considerable amounts of protein. The amino acids included glycine, serine, threonine, alanine, aspartate and glutamate. Experiments with heparin from porcine intestinal mucosa gave similar results.

Affinity chromatography of the highly active fractions on antithrombin-Sepharose showed that all of these materials are bound to the gel and that relatively large proportions are eluted with 1 M and 3 M NaCl.

It is concluded that the common heterodisperse heparin preparation contain a series or components ranging from extremely high activities to no activity. On the basis of the elution volumes of the fractions, the activities are directly related to molecular weight.
Association of the Platelet-Specific Alloantigen PIA1 (Zwa) with the Platelet Membrane Glycoprotein IIIa
Authors: Kunicki T.J. , Aster R.H.
Published: May 2019

We have previously shown that PIAtelets from patients with Glanzmann’s thrombasthenia are deficient in the membrane alloantigen. PIA1 (Zwa), found on PIAtelets of nearly all normal subjects. It was therefore of interest to determine whether the PIA1 marker is carried on one or both of the membrane glycoproteine (GP Hb and GP IIIa) known to be lacking in thrombasthenic PIAtelets. PIA1 antigen activity waa measured in an assay in which antibody-induced 51Cr release from enzyme-treated target PIAtelets is inhibited by test material. Membrane glycoproteins were isolated by sequential lectin affinity chromatography of DOCA extracte of PIAtelets, by indirect immunoprecipitation of detergent-solubilized extracta of 125-I labelled PIAtelets and by preparative SDS-PAGE electrophoresis. By each of the three separatory procedures, PIA1 was found to be associated with GP IIIa but not with other glycoproteins. PIA1 is situated on the portion of GP IIIa susceptible to cleavage in situ by trypsin but not by chymotrypsin, bromelain, or papain, requires intact disulfide bonds for its expression, and appears to be determined by a polypeptide sequence in GP IIIa rather than by a polysaccharide configuration. PIA1 appears to be the first alloantigen to be aseigned to a platelet membrane constituent and the fourth pep tide-determined alloantigen system to be assigned to a human cell membrane protein.
Increased Prostacyclin Generation in Minipig Vascular Tissue After Atherogenic Diet
Authors: Sinzinger H. , Clopath P. , Silberbauer K.
Published: May 2019

The effect of an atherogenic diet on PGI2-generation was studied in 24 miniature pigs fed a diet consisting of 25.6% lard, 2.65% peanut oil, 2.65% cholesterol and 69.1% commercial minipig chow. In all the minipigs the abdominal aortic endothelium was detached with an arterial embolectomy catheter. Prostacyclin generation in the thoracic and abdominal aorta and pulmonary artery was assessed in terms of inhibition of platelet aggregation compared with the effect of a synthetic standard. Blood and tissue lipid levels and the morphology of the arteries and different organs were examined. PGI2-formation was greater in the pulmonary artery, followed by thoracic and abdominal aorta. Balloon catheterization caused a 50% decrease in PGI2-synthesis. PGI2-production increased with ascending blood and tissue lipid levels; at the highest serum cholesterol level (1147 mg%) saturation of PGI2-release by the thoracic aortic segment was observed. In control animals (4) PGI2-generation in thoracic and abdominal aortic segments was 35% lower in the male than in the female pigs.
Reduced Polymerization of Factor VIII/Von Willebrano Factor in Variants of Willebrand’s Disease
Authors: Meyer D. , Obert B. , Piêtu G. , Zimmerman T. S. , Laverqne J.M.
Published: May 2019

F. VIII/vWF was isolated from plasma (1-3 ml) by preparative counter immunoelectrophoresis using rabbit anti-human F. VIII/vWF IgG. F. VIII/vWF was separated from IgG in the immunoprecipitants, without reduction, by SDS-1% agarose electrophoresis and analyzed by scanning at 540 nm. Multiple forms of F. VIII/vWF were observed in a series of increasing M.W. (1-10.106) when testinn normal (n = 5) and hemophilia A (n = 2) plasmas, cryo-precipitate (n = 3), or purified F. VIII/vWF (n = 31. Glutaraldehyde cross-linked IgM was used as marker. In classical vWD (n = 3), all molecular forms of F. VIII/vWF were present but in reduced quantities. In such cases, VIII:C, VIIIR:Ag (Laurell and I.R.M.A.) and VIIIR:RCo were reduced to the Same extent (30-40%) and there was no qualitative abnormality of F. VIII/vWF. In variants of vWD (n = 4, unrelated cases), only the 5 bands of lower M.W. (1-5.106) were present and in greater amounts than normal. These patients also lacked VIIR:RCo and showed an abnormal 125-I-radio-crossed immunoelectrophoretic pattern (lack of the large, slow-moving, forms of VIIIR:Ag) and an abnormal dose response curve by I.R.M.A., Similarities of the results by SDS-adifferent types of vWD.
Assessment of Clinical Hypercoagulability Tendency
Authors: von Kaulla E. , von Kaulla K.N.
Published: May 2019

Optimal assessment of hypercoagulability which may result in various types of intravascular clotting requires the following procedures. No storage of blood specimens, analyzation right after withdrawal of blood (with few persons involved in work), blood obtained with siliconized, not plastic syringes. Use of citrate Na as anticoagulant by only 20 % dilution, further dilution increases but does not decrease coagulability. Hypercoagulability can be correctly assessed with the thrombin generation test resulting in a curve leaving clotting factors in their natural relation and platelets in suspension. Synthetic substrates can be misleading. Some patients with a prothrombin time in therapeutic range have a normal thrombin generation showing that they are not protected. Short antithrombin III times reflect reduction of another protection against intravascular clotting. They must become prolonged by prothrombin-depressing agents, if not these agents are ineffective. Platelet aggregation induced by stirring only reveals another type of hypercoagulability tendency which cannot be treated with anticoagulants. Prolonged euglobulin lysis time reflects loss of yet another type of protection again, an intravascular clotting potential. Fast test for fibrin monomeres should be added. The tests mentioned revealed various types of hypercoagulability in most of the many patients who were referred to us for assessment of this tendency.
Anticoagulant Control with Chromogenic Measurements of Factors X and VII
Authors: Famodu A.A. , Ingram G.I.C. , Darby S.C.
Published: May 2019

Prothrombin time ratios (Manchester reagent) and parallel assays for factor X with Russell’s viper venom by coagulation (charcoal-filtered ox plasma) and chromogenic (S2222, pH8.6) methods were performed on plasma samples from coumarin-treated patients, following strict biometrical designs. Clotting times were read manually and colour change by spectrophotometer. Duplicate reaction tubes were read on each plasma in PTs and on each dilution tested in assays. Residual errors were calculated in logs. to homogenize the variance and expressed as coefficients of variation; the precision of assays was measured as λ=(residual SD)/slope. Readings of the S2222 end points were highly reproducible, but this did not yield better agreement between replicate reactions nor a significantly higher precision in assays . For stabilized patients, similar correlations were obtained between both assays and the PT ratio: for coagulation X, r31 = 0.897; for S2222 X, r36=0.902. Posterior probability density functions have also been calculated. Similar data for factor VII assays in newly anticoagulated and in stabilized patients will also be given.
Fibrinolysis in Serun Associated with Intrinsic Blood Coagulation
Authors: Wolf P.
Published: May 2019

The concept of a dynamic equilibrium between blood coagulation and lysis suggests that clotting and fibrinolysis are triggered off together during the coagulation sequence. To validate this hypothesis the fibrinolytic activity of serum has been investigated at various intervals after coagulation has occurred in normal blood by intrinsic clotting. The rate of fibrinolysis wae assessed by the effect of serum in causing the release of red cells from standard clots; and also by a fluorimetric method involving measurement of the liberation of soluble protein from Fluram (Roche)-labelled fibrin clots by serum. Both methods gave similar results in showing that fibrinolysis is maximal in fresh serum and diminishes rapidly in sterile serum incubated at 37°C. The time course of this process was studied by arresting the intrinsic coagulation of normal blood at various intervals after venepuncture by the addition of EDTA before clotting had occurred. Maximal fibrinolytic activity was found to develop at around 3 min. (i.e. about 7 min. before clot formation). The significance of these results will be considered in relation to: augmented fibrinolysis in disseminated intravascular coagulation; factors normally limiting the propogation of thrombi in veins; and the aetiology of pulmonary embolism.
Determination of Plasma Urokinase Levels by Chromogenic Assay Levels: Comparison of Levels Attained During Infusion of Tissue Culture and Urinary Source Urokinase Preparations
Authors: Barlow Grant H. , Marder Victor J.
Published: May 2019

Plasma urokinase levels were determined using the chromogenic substrate L-Pyroglutamyl-glycyl-L-arginine-p-nitroanalide (KABI S2444) on plasma samples collected before, during and after Infusions of tissue culture or urinary source urokinase (J, Lab. Clin. Med. 92:721, 1978). Each patient received a 2,000 IU/lb loading dose followed by an hourly rate of 2,000 IU/lb for 12 hours. There was no correlation between plasma urokinase level and critical concentration of drug or body weight and no difference in the effects of each preparation on laboratory reflections of a lytic state, such as the whole blood euglobulln lysis time, plasminogen or fibrinogen concentration. However, the chromogenic assay of urokinase activity showed that the urinary source material achieved a significantly higher plasma blood level at two hours and disappeared more rapidly after termination of the infusion than was observed with the tissue culture material. Although both urokinase infusions achieved plasma levels in excess of that required to produce a fibrinogenolytic state, it is likely that a significantly lower concentration is sufficient to produce a lytic state and that a larger dose of tissue culture material would be required to achieve this critical plasma urokinase level.
Treatment of Severe Pulmonary Embolism by Rapid Injection of Urokinase
Authors: Robert D. , Tempelhoff G. , Canamella A. , Thomas L. , Fournier G. , Ducreux J.L. , Gerard M. , Gioanni J.
Published: May 2019

Twenty severe pulmonary emboli (8 of which occured within S days of an operation) were treated by the injection, in a few minutes, of 10,000 to 15,000 CTA units/kg of Urokinase by peripheral (6 cases) or central (14 cases) IV route in conjunction with immediate effective heparinization, These severe pulmonary emboli were characterized mainly by a state of shock reversible a few hours after the administration of Urokinase ; 50% devascularization shown by diagnostic angiography, improved by an average of 41% in angiography 5 days after administration of Urokinase; hypoxemia in unaided breathing (average PaO2 : 40 Torr). Three deaths occurred 7, 31 and 40 days after Urokinase. In comparison with classic methods of treatment with Urokinase (UKII 85% - UKI 15%), this procedure is well tolerated, less dangerous (in terms of the bleeding factor), less costly and simpler ; but its efficacy, while evident, should be determined with accuracy.
Impaired Blood and Tissue Fibrinolysis in Patients With Recurrent Venous Thrombosis
Authors: Schiavoni M. , Parato M. , Ciavarella-Berlingerio R. , Frontera T. , Cicolella A.
Published: May 2019

Blood and tissue fibrinolysis were studied in 70 patients(p.) with recurrent venous thrombosis. The fibrinolytic activity and the release of plasminogen activators “fibrinolytic capacity” by 10 min. venous occlusion were detected by using acetate-buffered diluted clot lysis time, euglobulin lysis time and resuspended euglobulin precipitate on unheated fibrin plates. Plasminogen activator content in the wall of superficiel hand veins in 40 p, was measured by Pandolfi’s modified histochemical technique. Our studies showed a significantly low content of plasminogen activators in the vessel walls in, more then 60% of p. in good correlation with blood defective fibrinolytic activity and/or capacity.
Platelet Adhesion to Collagen is Inhibited by 5’ -Adenosine Diphosphate but Unaffected by Cell Shape
Authors: Meyer F.A. , Weisman Z. , Frojmovic M. M.
Published: May 2019

The effect of ADP on the adhesion of rabbit platelets to collagen from unstirred suspensions has been investigated. Reduced binding was seen at ADP concentrations sufficient for platelets in PRP suspensions to undergo shape change (>10-8M). However, shape change per se was not involved. The time dependence of the effect of ADP on platelet shape and on platelet adhesion did not correlate. Also reduced adhesion still occurred if shape change was prevented e.g. by treatment with 1 µM PGE1 or with fixatives. Washed platelet preparations in spite of being fully shape-changed also adhered less well in the presence of ADP. As expected platelets whose shape was changed without ADP being involved, e.g. by a cold exposure treatment, displayed normal binding to collagen.

ADP binding to the platelet per se is not sufficient, since reduced adhesion to collagen is seen only some time after binding has taken place. Also AMP blocked the effect of ADP on platelet adhesion if added before but not after ADP. The time dependent event that occurs is likely to be local since reduced platelet adhesion was seen with fixed platelets. It is unlikely to result from the conversion of ADP to ATP. Although ATP does inhibit adhesion, it does so only at much higher concentrations and then only after a lag period similar to that seen with ADP.

Our findings imply that some of the agents reported to reduce platelet adhesion to collagen may do so by causing ADP to be released from the platelet. Surface shape and chemistry
Rellase Reaction of Avian Thrombocytes
Authors: Krajewski T. , Wachowicz B.
Published: May 2019

Washed thrombocytes from geese, chickens and ducks were aggregated by serotonin, thrombin or acid-soluble collagen. During the process of thrombocyte aggregation only very small amounts of adenine nucleotides were released/about 1 % of total amounts/. However, proteins secreted during this process represented 10- 15 % of total thrombocyte proteins and resembled proteins from mammalian platelets. Chromatographic analysis /Sepharose 6B, Sephadex (G-100, SDS-polyacrylamide gel electrophoresls/of protein compounds released from thrombocyte showed the presence of 11 different protein fractions among which albumin, fibrinogen and β-thromoeglebulin constituted the main components, in the released protein material heparin-neutralizing activity was found.
Clinical and Experimental Evaluation of the Interaction of Anticoagulant Drugs with Radiologic Contrast Media
Authors: Moncada R. , Messmore H. L. , Fareed J. , Scanlon P. J. , Parvez Z.
Published: May 2019

Although clinical incompatibilities of antihistamines and protamine with radiologic contrast media are well recognized, no report is available on the interaction of heparin, Coumadin, dextrans and other anticoagulants with these agents. We have employed the automated activated clotting time (ACT), prothrombin time (FT), partial thromboplastin time (PTT) and the thrombin time (TT) methods to monitor the anticoagulant actions of contrast media and its interaction with various anticoagulant drugs in patients undergoing angiography, A strong synergism of the anticoagulant action of heparin was observed in patients given heparin along with contrast media. Studies conducted in human volunteers revealed that contrast media at a 1-5 mg/ml level (clinical, 0.5-0.6 mg/ml) produce a strong synergistic effect on the anticoagulant action of heparin, oral anticoagulants, dextrans, and antiplatelet drugs. When blood obtained from patients undergoing angiography was supplemented with 0.25 u/ml heparin, the ACT, PTT and TT were equal to 1.5-2.0 units of heparin. Conventional amounts of protamine are incapable of neutralizing this synergistic interaction. These studies show that contrast media temporarily augments the degree of anticoagulation in patients undergoing angiography, which should be taken into consideration in patients undergoing vascular angiography.
Functional Assessment of the Post-Thrombotic Limb by Foot Volumetry
Authors: Crawshaw H.M. , Ruckley C.V.
Published: May 2019

Functional assessment may be important in the selection of treatment for the post thrombotic limb. Phlebography demonstrates the anatomy of the veins and their valves but this information is often incomplete and does not necessarily reflect venous function. Pressure measurements correlate well with function, but this invasive technique is not practicable for routine use or repeated measurements.

Foot volumetry is a simple non-invasive technique which measures volume at rest and gives a continuous record of changes during exercise (Thulesius et al 1973). However reports on the reproducibility of this technique and its use in the study of venous function are few. On the basis of history, clinical examination and in those with suspected deep venous insufficiency ascending phlebography, 63 patients were divided into 3 groups: normal superficial varicose veins and deep venous insufficiency. There was good reproducibility. Preliminary analysis indicates that deep venous insufficiency may be diagnosed on the basis of a reduced expelled volume on exercise and a more rapid refilling phase after exercise. We conclude that foot volumetry is a useful non-invasive technique in the assessment of deep venous insufficiency. Further studies concerning its application to selection of specific treatment for the post-thrombotic limb are indicated.

Thulesius et al (1973)VASA 2 325-329
Subcutaneous Heparin in the Prevention of Venous Thrombosis After Elective Aortic Bifurcation Graft Surgery
Authors: Belch J.J.F. , Lowe G.D.O. , Pollock J.G. , Forbes C.D. , Prentice C.R.M.
Published: May 2019

In a randomised double-blind controlled trial 24 patients undergoing elective aortic bifurcation graft surgery received subcutaneous calcium heparin (2, 500 u preoperatively then 5,000 u 12 hourly or 7 days) and 25 control patients received saline injections. All patients received the routine dose of intravenous sodium heparin intraoperatively. The trial was terminated because of excess bleeding complications in patients on subcutaneous heparin (8 vs. 1, p<0.05). Deep venous thrombosis was diagnosed by 125I-fibrinogen scanning in 8 control patients and 3 patients on heparin (p>0.05). In this group of patients the risk of bleeding due to subcutaneous heparin appeared to outweigh the benefit of thrombotic prophylaxis.
Prevention of Deep-Vein-Thrombosis (DVT) in Hysterectomy Patients by Low-Dose-Heparin, Heparin-Dihydroergotamin and Acenocoumarol
Authors: Kunz S. , Briel R. C.
Published: May 2019

In major gynecological surgery an incidence of 15 - 35% DVT is found. However there are no data concerning the incidence of DVT following hysterectomy, the most common operation in gynecology. Therefore, in 288 patients undergoing elective hysterectomy a 125-J-fibrinogen uptake test was carried out, starting 2 hours postop and repeated every 24 hours for 8 days. Results: Of the 97 patients who received heparin alone (2 x 5000 IU/24 h) 15, 5% developed DVT. In the heparin-dihydroergotamin group (101 patients, 2 x 5000 IU heparin + 0 . 5 mg DHE) only 5, 9% positive scans were found (2p <0.05). In the acenocoumarol group (prophylaxis was begun 36 hrs. postop. in 90 patients) the frequency was 11.1%. Mean time for the onset in the heparin and heparin-DHE group was 4 and 3 days resp., in the acenocoumarol group 1 day. Duration of positive scans: 98, 53 and 50 hours. Localisation: 65 - 72 % calf-vein thrombosis;14 % bilateral in the heparin, 0 in the heparin-DHE and 9 % in the acenocoumarol group. No differences were registered in complications, side effects, blood volume insuction drainages, postop. fall of hemoglobin, standard morbidity and hematoma.
Inhalation of Heparin and its Effect on Blood Coagulation
Authors: Hellgren M. , Hägnevik K. , Blombäck M.
Published: May 2019

Heparin was administered by aerosol inhalation in principle according to Jaques et al. to 13 volunteers. The effects were investigated with activated partial thromboplastin tune (APT-time), thrombin-time and antithrombin III (Odegaard. Heparin concentration was measured in plasma according to Teien et al. and platelets were counted. Four volunteers received 700-800 IU heparin and 9, 1300 IU/kg b.w. Blood samples were drawn before, after and once a day for 10 to 21 days. Controls inhaled normal saline and blood samples were drawn for 12 days. No untowards effects were noted either on the day of inhalation or during observation period.

On the day of inhalation heparin concentration in plasma increased in the heparin-group but not in the control group. A maintained level of heparin was measured up to 3 weeks afterwards in 9 of the 13 volunteers. The heparin concentrations increased fren mean values of 0.014 IU/ml plasma to a maximal mean value of 0.040 IU/ml plasma in the high dose and 0.039 IU/ml plasma in the low dose group. During the observation period heparin mean level was about 0.020 to 0.030 lu/ml plasma in the heparin group. In the control troup there was no measurable heparin. The APT and thrombin times were prolonged during the day of inhalation in the high-dose but not in the lew-dose group. Antithrombin III and ptc remained unchanged in both groups and no changes were noted in the control group.
Heparin Treatment of Deep Venous Thrombosis: Clinical Usefulness of Blood Tests
Authors: Holm H.A. , Abildgaard U. , Bjerkelund Chr.
Published: May 2019

280 patients with phlebographically proven DVT have been treated with heparin infusion for 5 days followed by control phlebography. Daily blood samples were analyzed for heparin activity by 3 different assays (amidolytic assay, APTT, thrombin cl. time) to see if there exists a correlation between the clinical effects (on the local thrombotic process, on embolization, and on bleeding complications) and the results of laboratory tests.

Four patients suffered from major bleedings, and one was fatal. Compared to mean results, heparin activity was clearly exessive in three of these patients, particularly with the amidolytic assay. About ten per cent of the patients had minor bleedings.

A transient drop in the antithrombin concentration was observed in most patients, but sustained subnormal concentration (<70 %) was seen in ten patients. One patient developed thrombocytopenia and DIC. The influence of heparin dosage on heparin activity / concentration and on the thrombotic process will be evaluated.
The Measurement of Heparin by the APTT
Authors: Poller L. , Thomson Jean M. , Fletcher D. J.
Published: May 2019

In a previous international collaborative survey*, it was shown that some commercial PTT reagents and techniques were unsuitable for measuring the anticoagulant effect of heparin. In vitro studies, with a variety of commercial heparins further supports this finding. A similar pattern of results has also been obtained with blood samples from patients receiving parenteral heparin administration.
Heparin Standardization
Authors: Exner T. , Uhr E. , Rickard K.A.
Published: May 2019

Heparin is a major therapeutic item in any hospital and although local supplies are assumed to meet BP criteria, physicians often note differences in clinical results when the source of a supply is altered. BP and USP specifications require testing of heparins using animal blood thromboplastin tests - conditions which may not be particularly relevant to human use. A new method for determining heparin potency relative to a standard involves making equal dilutions of these heparins in several patients’ plasmas and determining the PTTK’s. The ratios of these PTTK’s to the initial PTTK of each plasma, when plotted for one heparin against the other, fall on a straight line and may be treated in the same way as recently proposed for thromboplastin calibration by the WHO. Features of heparin vary in importance depending on the particular application. Heparin used at high levels during bypass should be completely neutralizable by protamine. Mini-dose heparin needs to be standardised in terms of factor xa inactivation rate whereas that used for routine continuous infusion might best be standardised from its effect in vitro on the PTTK of normal plasma. We have recently investigated 3 tests for assessing heparins. 1. effect of their in vitro addition on the PTTK of normal plasma. 2. effect on factor xa inactivation. 3. protamine neutralisability as detected by the PTTK. The latter test was most accurate, demonstrating significant differences between sources of heparin and detecting variations in batch potency previously suspected by clinicians.
Behaviour of VIII—Related Properties in Response to Infusion of DDAVP in Patients With FVIII-Complex Disorders
Authors: De Mitrio V. , Petronelli M. , Ranieri P. , Vetrugno G. , Francia F. , Ciavarella N.
Published: May 2019

We have infused DDAVP(1-desamino-8-D-arginine vasopressin)(0,4ug/Kg b.w.) in 15-20 min., during tooth extraction, in 1 patient(pt) with moderate hemophilia A,2 pts with classical von Willebrand’s disease(vWd), 1pt with vWd variant and 2 pts with FVIII+FV combined deficieney. At fixed times from infusion (0.15’,6h,24h)we have studied the behaviour of FVIII-related properties (VIII:C,VIIIR:AG,VIIIR:RCo). In every pt DDAVP increased all 3 FVIIT-relatcd properties, particularly the VIII:C augmented 4-5 fold the basal levels in the hemophilic and FVIII+FV deficiency pts, while it always reached the normal levels in vWd pts. In one of classical vWd pts, DDAVP permitted us to estimate the electrophoretic mobility(EM) of FVIII-related protein(undosable at 0 time by Laurell technique)which resulted normal, In the pt with vWd vari ant(C=7%, RCo < 5%, AG=100%, abnormal EM)the RCo reached only 18% and the EM always maintained abnormal. In the FVIII+FV deficiency pts the response of FVIII-related properties was similar to the hemophilic pt, while FV did not undergo any increase.
Effect of Dextran 70 on the Platelet Distribution of Ex Vivo Thrombi
Authors: åberg M. , Rausing A. , Hedner U. , Bergent S.-E.
Published: May 2019

Infusion of dextran 70 impairs the function of factor VIII and increases the lysability of ex vivo thrombi. To find out whether this increased lysability is accompanied by any morphological changes of the thrombi dextran was infused into four healthy volunteers and one patient with von Wiilebrand’s disease. Dextran was also given to four dogs with 51Cr labelled platelets and 1-1abelled fibrinogen. The thrombi were studied in light microscopy and the distribution of isotopes measured. Dextran caused marked changes in the morphology of the thrombi. The platelet aggregates constituting the head were not formed and the platelets were more evenly distributed in the thrombi. The changes were most pronounced 2-4 hours after the infusion. In the patient with von Wiilebrand’s. disease the structure of the thrombus was abnormal already before the infusion of dextran. Even a small dose of dextran given to this patient prevented the formation of a platelet head. When factor VIII concentrate was given the platelet aggregates constituting the head of thrombus again formed. The findings indicate that factor VIII is of importance for the formation and coherence of the platelet aggregates in ex vivo thrombi. Dextran given intravenously reduces platelet aggregabiIity by impairing the function of factor VIII. The alteration of platelet function, accompanied bv profound changes in the morphology of ex vivo thrombi, may explain the increase in lysability which has been previously shown by us.