bluuebunny/crossref_metadata_2025 huggingface dataset:
Coagulation Disorders in Fulminant Hepatitis Treated by Dialysis
Authors: Morfini M. , Martinelli F. , Cinotti S. , Boncinelli S. , Mazzotta F. , Paci P. , Bandini S. , Tonelli F. , Cordopatri F. , Morettini A. , Pacini F. , Rossi Ferrini P.
Published: May 2019

A young man, 28 years old, was admitted to Infectious Division with transaminases over 2500 U/ml, reduced cortical activity and decerebrate posturing. A prolonged APTT, Prothrombin below 15%, very low levels of Factor II, V, VII (5-20%). At III by S-2238 (17%), Antiplasmin (20%) and Plasminogen(5%) by S-2251, Preltallikrein by S-2302 (5%). Fibrinogen (70mg%) but very high VIII AHF(4.5U/ml}, VIII AGN (4.0U/ml) and VIII VWF (3.8U/ml) were recorded. After 3 daily dialysis sessions with polyacrilonitrile membrane (RP 6) a marked improvement was observed. The patient awoke while prothrombin and platelet recovery took place, fibrinogen,VIII AHF and Factor V rose over normal value to 600mg%, 7.5U/ml and 3U/ml rispectively. Antiplasmin, Plasminogen, PKK showed a slow but costant improvement. Unfortunatly a venous thrombosis and sepsis set in during the 2nd day after dialysis, with a rapid decrease of platelets. Heparin infusion 1 mg/kg b.w. was infused every 6 hrs. After 15days platelet returned to normal value and VIII AHF to initial level but it was still higher (4U/ml) than normal value after 2 mounths from recovery.
Scoring System for Diagnosis of Disseminated Intravascular Coagulation (DIC)
Authors: Sutor A.H.
Published: May 2019

A scoring system for diagnosis of DIC is proposed which encludes anam estic, clinical and laboratory criteria. From anamnestic criteria triwerinp event which lead to microeirculatory disturbances, like peripheral stasis (hysovolaemia, cardia; insufficiency) thrombin-inducers (septicaemia, haemolysis) and vascular damage (haemolytic-uraemic-syndrome, g ant haemangioma) score1 point as well as a positive etnanol gelation test. Clinical parameters include all organs which show sirns of a throrr. ho-haemormafic syndrom. They represent shock-orpans and can be diagnosed clinically by simultaneous appearance of bleeding symptoms and microthromrosis, like oliguria and haematuria (shock-orean kidney) or purpura and “Intravital death sports” (shock-orfran skin) or haemoptoe and hyaline membrane (shock-organ lunps). Laboratory parameters of DIC include the annearanee of helmet cells, of leuko- or neutropenia, of thrombocytopenia and of the demonstration of consumption coagulopathy (low F I, II, V, XIII) and of fibrinolysis (increased FDP, low plasminogen, low Antithrombin III). From our experience a score of 7 points or more is compatible with DIC.
Methods of Analysis of Drug Action on Fibrinolysis in Vitro
Authors: Wolf P.
Published: May 2019

Drugs may Influence the rate of fibrinolysis in vitro la various ways: chloroform accelerates fibrinolysis by suppressing inhibitors of plasminogen activation or plasmin action; heparin accelerates fibrinolysis Indirectly by Inducing abnormal clot structure which is more susceptible to lyeia; 6-amlno-hexanoic acid has a dual mode of action it accelerates plasmin generation from plasminogen in plasma or serum or from plasminogen already absorbed on fibrin clots; simultaneously this drug competitively Inhibits further attachment of plasminogen to fibrin.

This is s demonstration of methods of analysis by which the above conclusions have been reached. The methods illustrated are; (i) baaed on measurement of red cell release from standard blood-elote; (ii) dependent on determination fluorlmetrically of the soluble protein liberated from labelled fibrin in the presence and absence of added plasminogen; and(iii) assay of the rate of plasmin generation using S2Z51 chromogenic substrate. The methods are fully documented and possible ways in which they may find applications for other investigations are also outlined.
Accuracy of Weighted Platelet Mean Life Span in 4-Day Platelet Survival Studies
Authors: Casals F.J. , Paulus J. M.
Published: May 2019

A platelet survival test of short duration, if available, would prove useful in clinical trials which evaluate the effects of antithrombotic agents. To determine the accuracy of a 4-day survival test the weighted mean of the linear and logarithmic estimates of mean longevity was computed from simulated data based on gamma (GA) or logistic-exponential (LE) functions of known mean longevities. Seventeen different sets of parameters were used for GA and 11 for LE. For each set the % circulating activity was calculated at 12 sampling times from 0.02 to 3.8 days and 30 simulated tests were created by introducing measurement errors having the same distribution as that experimentally determined in 28 normal subjects. The mean square error ranged from 3 .7 to 12.6 % for LE functions and 8.5 to 12.6 % for GA (except one value of 17.6 %). Eliminating all samples prior to 8hrs did not affect the mean error. By relying on the most significant part of the survival curve, the 4-day test appears as accurate as the 10-day one while promising to be easier to repeat and better accepted by patients
MDA Production in Human Platelets Subpopulations after a Single Intake of Aspirin, A Kinetic Study
Authors: Boneu B. , Sie P. , Eche N. , Caranobe C. , Bierme R.
Published: May 2019

Kinetics of platelet of various densities was studied using the MDA method. MDA nroduc-tion was stimulated by arachidonic acid (500/μM) and was measured on each four isolated Subpopulation according to Corash. The following points were checked : PRP preparation procedures do not exclude a platelet subpopulatioti with different characteristics of volumes and densities ; MDA production is equivalent whatever the platelet densities ; the reproducibility of the platelet separation into the four subpopulations is good (CV : 5 -10%) After a single intake of 0.50 g of aspirin (with 3 different volunteers) the following results are observed : (1) Between day 1 and 7 the curves of the WA reappearance in the four subpopulations are divergent. (2) On the seventh day, the MDA recovery in light platelets is near 90% but only 50% in the dense ones. (3) Between day 7 and 12, the MDA level in the dense platelets reaches the level of light platelets. These data suogest the two following hypotheses. (A) Young platelets are heterogeneous but mainly light ; during the first days of their life span, they nresent an increase in their density (analoqy with the erythrocytes), (B) The comparison of these results witn those of Corash (Blood, 1378, 52, 726) may suggest that light platelets would present a shorter turn over than heavy platelets.
Computerized Platelet Aggregation Analysis: A New Method
Authors: Zeller J.A. , Dayhoff R.E. , Ledley R.S. , Kulkarni Y.G.
Published: May 2019

Computerized Platelet Aggregation Analysis (CPAA) is a new direct, microscopic methedo-logy using image analysis to quantitate thousands of free platelets and aggregates in platelet rich plasma suspensions and determine the percentage of platelets present in discrete aggregate size groups. CPAA is sensitive to the earliest stages of platelet aggregation which are not recognized by light transmission aggregometry (0% change in light transmission). Platelets of ten normal irxiividuals aged 20-40 years were stimulated by a spin bar (SB) (1100 rpm) for a one minute and a ten minute period. The mean values are shown below for different aggregate size groups.

There is no significant increase in the number of aggregates between one and ten mirais of stimulation except for size group 9-40, which shows a minimal increment (P .025). All platelet suspensions contained aggregates of size group 3-8 platelets/aggregate and 4 of 10 specimens had aggregates of size 9-40,No aggregates larger than 41 platelets were found. CPAA can also be applied to the study of larger sized platelet aggregates induced in abnormal individuals.
Pre-Aggregation changes in plate let volume
Authors: Gear A.R.L.
Published: May 2019

Previous research on whether platelet volume increases durinq the morphological changes precedinq aqqregation is controversial; resistive-countinq techniques reveal an increase, centrifugal methods do noL. A computerized, resistive-particle counter has therefore been used to size platelets before and after incubation with ADP. The effects of EDIA and centrifugation were also evaluated. ADP (2 mH) significantly increased mean platelet volume from 4.81 to 5.47(p<.001). CDIA (2 mM) inhibited this increase by 50%, and both centrifugation and EDIA also caused platelet swelling.

Platelet shape was experimentally manipulated with colchicine, chlorpromazine and temperature cycling, to test the hypothesis that changes in resistive-volume stem from artifacts of particle shape. Scanning-electron microscopy confirmed that these treatments caused extensive sphering of disc-shaped platelets. However, subsequent exposure to ADP resulted in major increases in resistive volume, and in the case of chlorpromazine, no pseudopodia were extruded. It is concludedthat platelet volume can increase durinq pre-aqqreqation reactions, and that earlier research based on centri-Tuqation in the presence of EDIA failed tn reveal the increase because of inhibitory and swelling effects. This work mas supported, in part, by PHS Grants AM-20727, HL-1S289, and HL-7D759.
Platelet Rheoaggregometry in Native Blood
Authors: Musumeci V. , Zappacosta B. , Marra R. , Carloni L. , Ricerca B.M.
Published: May 2019

Platelet aggregation in vivo by shearing forces has been claimed to play the Pathogenesis of thrombosis. A physiological approach to the in vitro study of this phenomenon reguires the use of native blood ana a well defined shear rate. An apparatus was constructed by using a couette viscometer geometry in order to produce in 1 ml of native blood contained in disposable plastic tube a predetermined shear rate, the extent of platelet aggregation was measured by determining in the sample before and after shearing the platelet aggregate ratio according to the method of Wu and Hoak with minor modifications. A large series of unrela eu patients affected by miscellaneous disorders including symptomatic atherosclerosis was investigated by shearing blood for 1 min at a shear rate of 100 sec-1. No correlation was found between platelet aggregate ratios before and after shearing. Platelet aggregation ratio after blood shearing showed in atherosclerotic subjects a more evident trend toward abnormal values.
Myocardial Infarction and Coronary Thrombosis : A Rheological Evaluation
Authors: Dintenfass L.
Published: May 2019

A study of 94 patienis at Sydney Hospital and at the Royal Prince Alfred Hospital showed that a resolution and reliability of Theological (viscosity) methods is increased by a subraaxiraal exercise test (on a bike ergometer). Patients with more than 70% occlusion of the coronary arteries exhibit significant correlations between the maximum diastolic blood pressure ly, mmHg I and blood viscosity (x, cP) : y = 0.102x - 2.0 ± 1.57, r=0.608, and between the resting diastolic blood pressure and blood viscosity (at 180 rec. sec.) measured prior to the exercise test:y - 0.103x - 1.2 ± 1.02, r=0.797. Patients without severe coronary occlusion show a significant correlation only subsequent to the exercise test. All patients show a significant correlation between the square root of the sub-maximal exercise work (y, Kgm) and blood viscosity (x, cP):y = -11.29x + 154 ± 29, P < 0.05, and an even more significant correlation between the square root of the sub-maximal work and plasma viscosity: y = -180. 4x + 315 ± 28, P < 0.001. Furthermore, the viscosity of blood in the severe disease was significantly higher 16,45 ± 1.75 cP) than in ‘normals’ (5.44 ± 0.75 cP) or in highly fit men (4.94 ± 0.65 CP).
In Vivo Comparison of Heparin and Other Mucopolisacarids Antithrombotic effect
Authors: Szwarcer E. , Giuliani R. , Martínez Aquino E.
Published: May 2019

20 dogs(between 15-20kgs weight) were protected against experimental vein thrombosis using either heparin or M945 (orally absorbable, MW10-20.000 mucopolisacarid. Syntex Arg). Vein thrombosis was induced using XIIa-XIa con centrates, and the minimal concentration to be infused to each animal, that would induce a 4/4 size thrombous was determined. Stasis was induced with atraumatic clamps, and yugular and femoral veins were used. Heparin and M945 were compared in their KCCT, TT effects, related to their AntiXa potentiating effect. Differing from heparin, infused M945 has nearly no actions on KCCT or TT

The experience showed that with nearly no actions on blood coagulation, AntiXa was enhanced as when using heparin, and dogs were protected aeainst experimental thrombosis.

This results stress for the first time in in vivo studies the possibility of inhibiting deep vein thrombosis development without hemostatic changes
The Activation of Prothrombin by XIA & X2A and Inhibition by Fragment 1
Authors: Ong T.C. , Esnouf M.P.
Published: May 2019

The rate of conversion of prothrombin by Xa and Ca++ is increased 20,000-fold following the addition of Factor V and phospholipid. A comparison of the rates of thrombin formation ob tained with XIA and X2A showed that XIA had only 70% the activity of X2A. The addition of Fragment 1(2.4nmoles) to mixtures of Xa, prothrombin (4.3nmolesl, phospholipid and Ca++ reduced the rate of thrombin formation by 40%. This inhibition was relieved by adding an optimal amount of Factor V. When des-carboxy Fragment 1 was added no inhibition in the rate of thrombin formation was observed. These results suggest that the inhibition caused by Fragment 1 is dependent on intact γ - carboxyglutamic acid residues and is due to the competition for the Ca++ mediated prothrombin binding sites on the phospholipid or Xa. The effect of Factor V in abolishing the inhibition caused by Fragment 1 indicates the importance of the interaction of prothrombin with Factor V in forming the prothrombinase complex.
Antithrombin III (At III) in Factor IX Concentrates
Authors: Gomperts Edward D. , Izadi Parvin
Published: May 2019

AT III was assessed in different batches of two commercial Factor IX concentrates. The assay procedures were the Laurell QIE for AT IIIAGN with functional activity being assayed using both a commercial kit and the chromogenic substrate S2160. There was considerable variation between the separate products and among the different batches. In one product. AT IIIAGM varied between 2.6 and 15%, the other between 75 and 145% of pooled control plasma. Functional activity assessed with the commercial kit varied between batch and products but generally was greater than antigen in one product; less than antigen in the other. S2160 dependent assays failed to corre Hate with these levels. The chromogenic system demonstrated considerably more functional activity in all samples tested. Heparin failed to induce heparin co-factor (HCF} activity as assessed by the S2160-IIa, S2222-FXa and thrombin-fibrinogen systems. This observation was confirmed by 2DIE where all samples failed to show increased heparin-induced migration. It can be assumed that AT III in at least some commercial concentrates contains AT IIIAGN. This AT III has no HCF activity but functional activity varies considerably depending upon method of assay. α1 AT and α2M antigen are present, but in considerably smaller guantities than AT III.
Plasma ß-Thromboglobulin and Glycosylated Hemoglobin(Hb A1) in Type I and Type II Diabetes Mellitus
Authors: Schernthaner G. , Silberbauer K. , Sinzinger H. , Müller M.
Published: May 2019

Platelet hyperactivity is a common feature in diabetes meliitus. ß-thrombo-globulrn (ß-TG) - which is released during platelet aggregation - seems to be a useful Index of platelet involvement in thrombotic disease. Howeverthere is no detained information regarding metabolic control on platelet function in diabetes me 1litus, Therefore we studied the plasma ß-TG concentrations and the hemoglobin A1(Hb Airparameter of diabetic longterm control)levels in 7o patients with type-I(insulin-dependent) diabetes(D), ibo patients with type II D (non-insulin-dependent)as well as in 70 healthy controls (C). Plasma-ß-TG levels were determined by radioimmunoassay, Hb Al concentrations by ion-exchange chromatography. ß-TG levels were significantly increased in type-I and in type-II D compared to C (p<0,01, resp.<0,0011. Hb Al concentrations were significantly higher in both groups of diabetics than in the C <p< 0,005, resp. <0,005). No correlation could be found between the ß-TG levels and the Hb A1 concentrations neither in the type I nor in the type II diabetics. These data suggest that the degree of metabolic control is not the main factor in disturbed platelet function in diabetes mellitus.
Quantitative Index of the Blood Clot Elasticity
Authors: Pieptea R. , Pieptea M. , Pieptea D.
Published: May 2019

One of the most characteristic feature of the blood clot is the elasticity, its capacity of doing passively a mechanical work. The information about this property given by the thrombelastographic Am is quite relative, Mathepltical Modelling of the active phase of the blood coagulation, phenomenon,

allowed us a proper evaluation of this quality, by the definite integral of the function. The index of the clot elasticity (Q) can be calculated according to the formula:

and represents the relative value (Q%) of the clot elasticity obtained, in the sample of blood to be examined, against the absolute value (100%) in the hypothetical case with sudden coagulation and inextensible fibrin.

The normal values of this index are: 17 < Q < 25%. Underneath, (Q < 17%) there is a reduced elasticity, so as above,(Q > 25%), the figure snows, an increased elactricity.

a, xc and xm are parameters which can be measured on the thrombelastographi tracing. λ is calculated:

.
Haemorheological Effects on Thrombocyte Adhesion and Aggregation Found Under Controlled Flow Conditions
Authors: Richardson P.D.
Published: May 2019

Thrombocyte adhesion and aggregation in a vessel or on a chamber wall can be measured most readily if the flow is controlled and steady, and continuous observation is used. Videotape recording is very helpful for subsequent quantification of the dynamics. The adhesion of each thrombocyte can occur for a finite time interval:this interval has been observed to have a wide range. Platelets which escape often leave open a site which attracts other platelets preferentially. The rate of change of adhesion density (platelets/mm2) is affected by the local shear rate and the shear history upstream. Aggregation is affected similarly, and also proceeds with some platelet turnover. The role of erythrocytes in facilitating cross-stream migration of thrombocytes (which can enhance the growth rate of large thrombi) appears due in part to convective flow fields induced by the motion of erythrocytes in a shear flow, which can be demonstrated theoretically and experimentally. Observations of the phenomenlogy of adhesion and aggregation under controlled flow conditions and comparison with fLu id-dynamically based theory allows representation in terras of a small number of parameters with prospects of prediction of behaviour over a wide range of haemodynamic conditions; biochemical changes lead to changes in values of the parameters, so that activating agents and inhibiting agents modify values in different directions.
Factor VIII Structure and Function: Progress and Problems
Authors: Zimmerman T.S.
Published: May 2019

The last several years have seen considerable progress in our understanding of Factor VIII. Factor VIII has been shown to exist in vitro as different size multimers of the 200,000 MW subunit. The von Willebrand “bleeding time” factor appears to reside in the larger multimers whereas the Factor VIII procoagulant activity is associated with all of the different size forms. It has been suggested that this size heterogeneity results from in vitro changes. The role of carbohydrate in the Factor VIII von Willebrand function has been the subject of considerable study. It is clear that altering the carbohydrate composition of the Factor VIII molecule reduces or abolishes its ristocetin cofactor. Initial studies of Factor VIII carbohydrate in von Willebrand's disease showed it to be decreased. However, more recent studies of larger numbers of patients showed normal carbohydrate content in the great majority, even in those who lack von Willebrand factor activity. The ristocet in cofactor test has been of great help in defining relationships of the von Willebrand factor to factor VIII procoagulant activity yet the ability of ristocetin cofactor activity to truly reflect the bleeding time abnormality is open to question. The relationship of the Factor VII procoagulant activity to the Willebrand factor also remains a subject of controversy. Though Factor VIII procoagulant activity can clearly be separated from the von Willebrand factor in vitro, the in vivo relationship is unclear. Recent evidence has suggested that Factor VIII procoaguJant activlly may function as a serine esterase. However, the precise manner in which Factor VIII procoagulant activity exerts clot promoting functions is still a mystery.
The Relationship of the Quaternary Structure of Factor VIII to its Biological Activities
Authors: Counts R. B. , Paskell S.L.
Published: May 2019

Purified factor VIII exists as a homologous series of multimers in which the protomeric unit is a dimer of the basic subunit. On reduction by 2-mercaptoethanol, clotting activity (VIII:C) persists at 90% of the initial activity when the only species present are monomers and dimers. In contrast, Von Willebrand activity (VIII:VWF) is lost concurrently with the disaggregation of multimers and is decreased to 5% of the starting activity when only monomers and dimers remain. VIII:Ag reactivity with rabbit antibody is Likewise lost on reduction, but the VIII:C activity of the reduced protein is inhibitable by hemophilic a-VIII antibodies. Unreduced VIII binds to fresh or formalin fixed platelets in the presence of ristocetin or vancomycin. Although the apparent Ka for binding is high, approximately 5 x 108 M-1, binding is dependent on an excess or ristocetin. On removal of ristocetin or vancomycin by serial dilution, platelet-bound factor VIII readily dissociates. Reduced factor VIII also binds to platelets in the presence of ristocetin with a Ka of approximately 108M-1, but does not cause platelet aggregation. These data suggest that the multimeric structure of factor VIII is not necessary for VIII:C activity nor for binding to platelets but may be important for VWF platelet-aggregating activity.
Enzymatic Degradation of the Factor VIII-Von Willebrand Protein:A Unique Tryptic Fragment with Ristocetin Co-Factor Activity
Authors: Martin S. E. , Marder V.J. , Francis C.W. , Loftus L.S. , Barlow G.H.
Published: May 2019

Highly purified von Willebrand protein was obtained from pooled human cryoprecipitate using polyethylene glycol precipitation followed by agarose gel chromatography, and concentrated by dialysis against 20% polyethylene glycol-20,000. Subsequent partial hydrolysis with trypsin destroyed all of the procoagulant activity and 97% of the ristocetin co-factor activity of the original purified material. Such digests were gel filtered and then analyzed by determinations of biological activities and by SUS-Polyacrylamide gel electrophoresis. All of the ristocetin co-factor activity present in the digest was found in a 100,000 dal ton fragment. Larger fragement thmoecular weights 150,000-260,000 daltons as well as smaller fragments (< 50,000) lacked ristocetin co-factor activity. Fragments smaller than 50,000 dal tons did not react with heterologous antisera. These observations suggest that the ristocetin co-factor activity of the intact von Willebrand molecule is located in one or more specialized regions, partially retained in this unique intermediate-sized tryptic degradation product.
Factor VIII Clotting Antigens Studied by Immunoradiometric Assay
Authors: Peake I.R.
Published: May 2019

Antigens related to procoagulant factor VIII (FVIIIC) were detected and measured using an immunoradiometric assay based an an inhibitor to FVIIIC which arose in a poly transfused severe haemophiliac. Good agreement between FVIIIC and FVIIIC antigen (FVIIICAg) is seen in normal and mild von
Willebrand’s disease (vWd) plasma while in severe vWd levels of FVIIICAg up to 5% are recorded. In haemophilia, FVIIICAg le vels are reduced generally to a level below that of FVIIIC. FVlllCAg is also present in serum and is stable at 370 for 24 hours in plasma. Thus its measurement has
considerable potential for the diagnosis of haemophilia, particularly in blood samples obtained from the young infant, umbilical cord, or fetus. FVIIICAg was assayed in several factor VIII concentrates and the ratio of FVIIICAg to FVIIIC correlated with the degree of purification of the concentrate. Unlike FVIII related antigen (FVIIIRAg) FVIICAg was not detected in human card endothelial cell culture medium, and was present in only law levels in washed platelets. Results of gel filtration of plasma FVIIICAg depended on the anticoagulant used but in general FVIIICAg was often detectable without FVIIIC or FVIIIRAg in the included fractions. The results confirm the existence of two broad types of factor VIII antigens and are consistent with the two molecule hypothesis on the nature of factor VIII.
Microrheology of Normal and Platelet Aggregate-Containing Blood
Authors: Benner K.U.
Published: May 2019

Preformed arterio-venous (a-v)-shunts are assumed to be the normai pathway for the non-nutritive portion of total blood flow passing different organs. Partial or total blockage of minute vessels can result in a redistribution of flow towards these a-v-channels. There is, however, a substantial area of circulation, where the existence of a-v-shunts sensu strictiori has been denied (e.g. in the skeletal muscle). Therefore, experiments were designed to study microrheolcgical effects of ADP-induced platelet aggregates (or latex globules, ϕ 25/um) on isolated and autoperfused canine gastrocnemius muscles. During volume-constant perfusion of the maximally vasodilated, resting muscle the capillary transport coefficients (PxS) of 4-amino-antipyrine (indicator diffusion method; CRONE, 1963) decreased from 138.2 ± 25.9 to 21.3 mlxmin-1 x 100g-1 upon microembolization, During pressure-constant perfusion the aggregates produced likewise a decrease of PxS in the working muscle associated with an increase of flow resistance and a decrease of O2-uptake and muscle performance. It is concluded, that the capillary exchange surface is reduced by aggregate-emboli decreasing the wor-capacity of the muscles, and due to the microembolization some fraction of muscle blood flow may be non-nutritional.
The Influence of Shear Rate and Red Cell Concentration on Platelet Adhesion and Thrombus Formation in Human Blood
Authors: Turitto V.T. , Weiss H.J. , Baumgartner H. R.
Published: May 2019

The interaction of platelets with subendothelium requires the transport of platelets to the vicinity of the surface, as well as the basic cell-surface reaction. Exposure of subendothelium to human citrated blood flowing in an annular perfusion chamber at wall shear rates (α) of 50-10,000 sec-1 indicates that a diffusion controlled (DC) transport regime exists below 650 sec- l in which platelet adhesion (C+S) was strongly dependent on α, and thrombus formation (T) was absent . Above 800 sec-1, an apparently reaction controlled (RC) regime predominates in which C+S was independent of α, and T increased in both extent and size. Variation of hematocrit (H) from 0-701. in the RC regime (2600 sec-1) lead to a steady increase of C+S with H, and an exponential increase in T as H increased from 30 to 70%. In the DC regime (200 sec-1) virtually no thrombi were formed for all H, and C+S increased as H increased to 40%; above 40%, C+S became independent of H. Thus, at low α (venous), the platelet-subendothelial reaction is controlled primarily by the arrival rate of platelets at the surface and the red cells increase this transport for H up to 40%. At high α (microcirculatory) , the platelet-vessel wall reactivity becomes more dominant and red cells increase the ability of platelets to attach to the subendothelium.
Malignancy and the Haemostatic System; Introductory Remarks
Authors: Donati Maria Benedetta
Published: May 2019

The haemostatic system, with the complexity of its various components, comprises a number of activities which may play a role in tumor growth and metastasis formation. In particular, the ability of some cancer and/or leukemic cells to adhere to and cross the vascular endothelium, to induce platelet aggregation, to release procoagulant and/or fibrinolytic activities, to adhere to polymerizing fibrin and other substrates (such as collagen) could influence their invasive potential. In vitro observations on such properties of cancer and/or transformed cells have received over the past 20 years, some experimental in vivo support, although indirect. Treatment with drugs active on the haemostatic system has proved effective in reducing metastatic growth in some instances. However, both the suitability of the models used and the mode of action of the drugs employed have been
questioned. As a paradigmatic example, the mechanism where by warfarin reduces metastasis formation in a number of experimental models is still a matter of discussion. Finally the shift from experimental work to possible clinical application presents a number of difficultures. Nevertheless, some preliminary information is available which could orient future efforts in this puzzling field.

Supported by CNR (Italy) and NIH, NCI (USA).
Requirement of a Plasma Factor for Platelet Aggregating Material (PAM) Extracted from Tumor Cells
Authors: Pearlstein E. , Karpatkin S.
Published: May 2019

Platelets are required for experimental tumor metastases and severallines of tumor cells aggregate platelets. We have extracted a sedimentable sialo-lipo-protein from SV40 transformed Balb C3T3 fibroblasts which is capable of aggregating heparinized rabbit or human platelet rich plasma (PRP) at 2.5 ng/ml via the release reaction; whereas a similar extract obtained from non-transformed 3T3 cells barely has activity at 40 μg/ml. PAM activity is not inhibited by collagenase (310 units/ml) but is inhibited by neuraminidase (2 mg/ml), trypsin (l ug/ml) or boiled phospholi pase A (0-1 ug/ml)-Platelet aggregation is preceded by a 1 minute (avg.) lag period in PRP, and can be inhibited by EDTA (5mM), indomethacln (0.05 mM). adenosine (0.1 mM) and dibutyrl cyclic AMP (0.1mM). Gel filtered (washed) platelets do not aggregate with PAM. However, reconstitution withplasma results in typical PAM-induced platelet aggregation preceded by a lag period. PAM binds to platelets. When PAM is coupled to sepharose beads treated with cyanogen bromide, platelets adhere to these beads. PAM-sepharose beads, aggregate PRP, as well as washed platelets in the presence of a plasma factor, following a lag period; sepharose beads alone or sepharose beads coupled to albumin or fibrinectin have no effect. The lag period can be abolished by prior incubation of plasma with PAM for 5 min at 37°C. The plasma factor is labile at 56°C for 30 min. However, the PAM-plasma productis stable to heating at 56°C for 30 min. These data suggest that the plasma factor may be a labile enzyme which con-
Plasminogen Activator Released from malignant Tumours
Authors: Åstedt B.
Published: May 2019

Urokinase-1ike plasminogen activators are released from carcinomas in vitro and in vivo. In organ or cell culture of ovarian carcinoma three forms of plasminogen activators with molecular weights of about 90,000, 54,000 and 31,000 daltons are released with mainly the high molecular weight forms in early cultures and low mol ecu lar weight forms in late cultures. They are inactivated by diisopropylfluoronhosphate and resemble urokinase in respect of active site and Immunologic determinants. Eased on the cross-reaction between urokinase and tumour plasminogen activator a radio immunoassay was devised using urokinase of 50,000 daltons and monn-specific antiserum against this fraction, and applied for determination tumour plasminogen activator.

Tumour activator and urokinase are neutralized by the naturally occurring inhibitors alpha2-antiplasmin, alpha1-antitrypsin and alpha2-macroglobulin. An inhibitor derived from placenta inhibits the tumour plasminogen activator and urokinase, but not the tissue plasminogen activator.
Stypven Time Measurement of Plasma After Filtration: Effects of Cigarette Smoking
Authors: Chao F.C. , Tullis J.L. , Alper C.A. , Silbert J. E.
Published: May 2019

Normal plasma contains nonsedlmentable platelet factor-3 (NS-PF3) activity, thought to be caused by circulating platelet membrane fragments. Stypven time (ST), an assay for PF-3 activity, of plasma prepared by differential centrifugation and by filtration through 0.22 μ Millipore filters were Investigated. The average ST for platelet-rich plasma (PRP), low-spin platelet-poor plasma (LSPPP), medium-spin PPP (MSPPP), high-spin PPP (HSPPP) and filtered PPP (FPPP) was 28.0, 40.4, 43.4, 61.7 and 65.5 sec, respectively (27 determinations). Filtration of plasma did not affect factor V and X activities. Material eluted from filters after filtration of plasma consisted of membrane vesicles with high PF-3 activity. ST were then measured in plasma preparations obtained from smoking (S) (>15 cigarettes/day) and nonsmoking (NS) healthy male individuals, ages (A) between 45-64. Data obtained were grouped according to age and smoking habits (Gr. I, 9 S, A 45-64; Gr. II, 14 NS, A 45-54; Gr. III, 7 S, A 55-64; Gr. IV, 14 S, A 55-64) and subjected to two-way analysis variance employing the BMDP2V program. Significant shortening of ST was noted in LSPPP (p<0.02) and MSPPP (p<0.02) in smoking groups which, however, showed no significant differences in PRP (p>0.8), HSPPP (p>0.06) and FPPP (p>0.4). Results suggest smoking individuals exhibit significantly higher NS-PF3 activity in plasma.
Human Platelets Possess an Inducible and Saturable Receptor Specific for Fibrinogen
Authors: Edgington T.S. , Marguerie G.A. , Plow E.F.
Published: May 2019

Fibrinogen is required for ADP-dependent aggregation of human platelets; but the molecular basis for the requirement is not: known. Fibrinogen, rendered free of fibronectin, plasminogen, VIII, II and XIII, was radiolabelled (125I-fg) and used as the probe for a platelet receptor. Platelets were isolated by differential centrifugation, washed in calcium-free Tyrode’s solution containing 0.2% albumin and isolated by exclusion from Sepharose CL 2B. 125I-fg bound to platelets only after ADP stimulation, and binding was characteristic of a saturable receptor. Specificity was established by demonstration that fibrinogen completely inhibited binding of 125I-fg, competing with the same affinity, whereas other proteins were without effect. SDS polyacrylamide gel electrophoresis of the platelets after reduction demonstrated 125I polypeptide chains with migration identical to Aα, Bβ and γ chains; and fibrinopeptide A was on the bound 125I-fg indicating that fibrinogen per se is bound. Scatchard analysis of binding at optimal concentration of ADP (≥ 5 μM) indicated 4,644 ± 186 receptors with a
dissociation constant Kd = 1.3 x 10-7 M, comparable to that estimated directly from the aggregation reactions. Receptors induced at different ADP concentrations appeared to have the same affinity for fibrinogen, indicating the probable existence of only a single class of receptors. We conclude that a specific saturable receptor is rapidly induced on human platelets by ADP, and postulate that this event may play a Significant role in the observed in vitro aggregation phenomenon and perhaps the primary hemostatic function of platelets. Supportedby NIH grant HL-16411.
Purification of a Plasminogen Activator from Venous Occlusion Plasma
Authors: Binder B.R. , Spragg J.
Published: May 2019

Following 15 minutes venous occlusion blood samples were drawn from human volunteers into EDTA and Polybrene as anticoagulants. The plasma of each donor (60-80mls) was fractionated by reverse (NH4)2SO4 gradient solubilization, elution from octyl-Sepharose with 50% ethylene glycol, and sequential gel filtration according to the method described for the purification of vascular plasminogen activator (Binder et al. JBC, 254, 1979, in press). A plasminogen activator (PA), demonstrately active on a plasminogen-rich but in active on a plasminogen-free fibrin plate, was purified by this procedure and characterized as having an apparent MW of 65.000-72.000, a pI of 8.0 - 8.3, and yielding a single protein stainable band on acid disk gels a t the region of PAactivity eluted from gels run in parallel. From the elution pat terns on the different columns used in the purification scheme, from the molecular weight value, the isoelectric point, and the mobility on acid polyacrylamide gels, it is concluded that the presently isolated and purified PA is identical to that already described as vascular plasminogen activator.
Activation of Normal and Abnormal (Genetic Variant) Human Factor IX
Authors: Bertina R.M. , Linden I.K. van der
Published: May 2019

Isolated human factor IX (single chainjjMW 63,000) has been activated in three ways;

a) in the presence of factor XIa and Ca2+ active 2-chain factor IXa (MW 47,000; MWHC 27,500) is formed via an inactive 2-ehain intermediate (MW 63,000, MWHC 44,500);

b) in the presence of thromboplastin, factor VII and Ca2+ essentially the same sequence of reactions takes place as sub a;

c) in the presence of RVV-X active 2-chain factor IXa (MW 63,000; MWHC 30,0001 is formed The dependance of these three reactions on the Caconcentration has seen studied.

A genetic variant of factor IX was found that like PIVKA IX can be separated from normal factor IX by electropheresis in the presence of Ca. Again like PIVKA IX this variant shows a strongly reduced affinity for binding to Al(OH)3. These findings suggested an abnormality in the Cabinding properties of this variant.

The activation of the isolated variant factor IX by the foremen!ioned activators will be compared with that of normal factor IX.
In Vivo Activation of the Extrainsic Pathway by F.E.I.B.A
Authors: Mariani G. , Romoli D. , Salvitti C. , Avvisati G. , Hassan H.J. , Mazzucconi M.G.
Published: May 2019

The effect on extrinsic blood coagulation pathway of the infusion of different doses (10 to 100 U./Kg b.w.) of FEIBA in three hemophiliacs with high-titre inhibitor was studied. The concentrate induces a striking shortening of Thrombotest strictly related to the infused dose. The shortening of Thrombotest seems to be due to an activation of factors VII and X. The antigen related to factor VII remains always at the prelnfusion levels. Factor VII-like activity induced in vivo by FEIBA is dramatically reduced after a 24 hrs, in vitro incubation at 4°C with heparin (1 U./ml). No significant changes were observed concerning Fibrinogen, FDP, At-III (amidolytic) and Platelet count, whatever dose was given. These data suggest that FEIBA induces in vivo a strong activation of recipient’s own factor VII and X) proportional to the dose. This activation is short living and its 50% disappearance time is of 210 minutes.
Suloctidil Does not Inhibit Vascular Prostacyclin Activity in Rats
Authors: Villa S. , Cavenaghi A.E. , de Gaetano G.
Published: May 2019

Suloctidil [1-(4-isopropyl-thiophenyl)-2-n-octylaminopropanol, Continental Pharma, Belgium] is a drug which inhibits platelet aggregation in human beings and possesses antiplatelet aggregation and antithrombotic properties in several animal models. In the present study, the acute effect of suloctidil on vascular prostacyclin activity was evaluated in rats.. Male CD rats (250-300 g) were given the drug (200-400 mg/kg b.w.) orally 1 h before testing. Prostacyclin activity was measured as the plotelet aggregation inhibitory potency of supernatant buffer following 4 min incubation with rings of either abdominal aorta or inferior vena cava. Treatment with suloctidil did not induce any significant modification of prostacyclin activity. In contrast, in vivo platelet aggregation induced by i.v. infusion of ADP (1 mg/kg) or collagen (2.6 mg/kg) was significantly (p < 0.001) inhibited. It is su.ggested that suloctidil may interfere with platelet function without affecting the potential antithrombotic activity of the vascular wall.
Purification of Staphylocoagulase by a Bovine Prothrombin-Sepharose 4B Column and its Physicochemical Properties
Authors: Igarashi H. , Morita T. , Iwanaga S.
Published: May 2019

Staphylocoagulase is known to coagulate human plasma, but not bovine’s, by forming an active molecular complex with prothrombin. However, there is no enough knowledges in respect to the molecular mechanism of prothrombin activation with staphylocoasulase. A new simplified method was developed for the large-scale purification of coagulase from culture filtrates of Staphylococcus aureus. strain st-213, using Sepharose AB covalently linked with bovine prothrombin. This affinity column adsorbed strongly the coagulase, which was eluted with 1.0 M NaSCN. The yield of coagulase activity was in the range of 75 to 85X, The purified coagulase showed a single symmetrical peak by ultracentrifugal analysis (S20,w=6.47), and it gave a single precipitin line against anti-purifled staphylocoagulase serum, as revealed by the immunodiffusion test. However, the preparation was shown to contain three active components by the isoelectric foccusing method, suggesting some microheterogeneity. The molecular weight estimated by SDS-gel electrophoresis was 71,000 (major material). No cystine residue was found in the purified material and its NH2-terminal sequence was Ile-Ile-. It is of interest that staphylocoagulase interacts strongly with bovine prothrombin-Sepharose AB, whereas it does not form any active complex with the prothrombin, unlike human prothrombin.
Selective Binding of Different Molecular Species of Factor VIII to Isolated Human Platelet Membranes and to Intact Thrombin Stimulated Platelet
Authors: Koutts J. , Zimmerman T.S.
Published: May 2019

Factor VIII is a necessary co-factor in the primary haemostatic interaction between platelets and the subendothelial tissues exposed at sites of vascular damage. We present evidence here of direct binding of factor VIII to isolated human platelet membranes (without the requirement of ristocetin) and to thrombin stimulated intact platelets. This binding is saturable and a function heterogeneity for-factor VIII, corresponding to its known molecular heterogeneity can be demonstrated. Thus, in normal plasma, only the larger molecular forms of VIII:Ag bind to platelet membranes. Various fractions of plasma VIII:Ag enriched in the larger molecular form of VIII:Ag, such as cryoprecipitate, the heavier fraction on sucrose density gradient ultracentrifugation and the void volume fraction of a 4% agarose column show a high percentage of VIII:Ag binding. Conversely the cryosupernatant, the lighter fractions from a sucrose idensity gradient and the VIII: Ag eluting after the void volume fraction of a 4% agarose column show little, if any, :binding to platelet membranes. In patients with typical von Willebrand’s disease, who have reduced levels of qualitatively normal VIII:Ag, a normal proportion of their VIII: Ag binds. In “variant” von Willebrand’s disease, where there is a plasma , deficiency of the larger molecular forms of VIII:Ag and a disproportionately low ristocetin co-factor activity; there is no significant binding of their plasma VIII :Ag. A number of commercial factor VIII concentrates are also shown to be relatively depleted of the large VIII:Ag form and to have a very low platelet binding capacity. Physiologically, thrombin appears :to be an initiator of the factor VIII - platelet interaction.
XaI (Antithrombin III) Activity in Relation to Postoperative Deep Vein Thrombosis (DVT)
Authors: Wallenbeck I. , Bergqvist D. , Hallböök T. , Yin E.T.
Published: May 2019

65 patients (21 controls, 20 low-dose heparin, 24 dextran) undergoing hip or elective general surgery were tested for Xal activity with a Differential Xal Assay. The test uses activated F X as substrate for determining the biological activity of Xal in two test systems. 1) Comprehensive test measures the ability of undiluted plasma to neutralize Xa in presence of circulating accelerators or antagonists of Xal. 2) Specific test quantitates total Xal activity in a highly diluted plasma system. For screening of DVT, 125-fibrinogen and/or thermography was used. Classification into minor and major DVT was made. Mean preoperative Xal was 8-10% lower in patients who developed postoperative DVT (both tests). Hip fracture patients had significantly lower initial values than patients undergoing elective surgery (comprehensive test). Postoperatively, Xal activity in patients with minor or no DVT remained constant. In patients with major DVT, Xal activity was significantly lower (20-45% in comprehensive and 15-30% in specific test) on operation and first two postoperative days and then returned to preoperative levels. Patients who developed OVT showed the same pattern of Xal despite prophylaxis. Of 14 major DVT, 10 were diagnosed when Xal activity had normalized. This indicates that a decrease in Xal activityimmediately after trauma, can identify patients disposed to develop major thromboembolic complications.
Collagen as a Substrate for Tissue Transglutaminase
Authors: Jeleńska M.M. , Fésüs L. , Kopeć M.
Published: May 2019

Heat-denatured (60°C for 1 h) unlabelled and [125I]-labelled type I and type III calf skin collagers were found to be crosslinked into high molecular weight polymers by guinea pig liver transglutaminase as demonstrated by SDS gel electrophoresis. Transglutaminase catalyzed incorporation of [14C]-putrescine into all subunits of denaturated collpgen of both types. This enzyme also catalyzed the formation of co-crosshnks between denaturated type I and III collagens and fibrinogen, fibrin as well as fibrin already crosslinked by factor XIII. Factor XIII was not effective ir-induction of these reactions. Non-denatured collagens both soluble and in the forn. of reconstituted fibrils were neither crosslinked nor co-crosslinked with fibrin and fibrinogen by liver transglutaminase. The results presented indicate that glutamine and lysine residues cf collagen in its native state are not accessible for liver transglutaminase, vhich catalyzes formation of crosslinking glutamyl bonds.
The Diagnosis of Established Deep Vein Thrombosis
Authors: Hull R. , Hirsh J.
Published: May 2019

It is now generally accepted that the clinical diagnosis of deep venous thrombosis (DVT) is inaccurate both because of low sensitivity and specificity. Because more than 50% of symptomatic patients fail to show thrombi on venography, anticoagulant therapy on the basis of clinical symptoms of DVT is not acceptable. Venography has been the standard reference method for the diagnosis of DVT but is invasive and consequently associated with patient morbidity. Impedance plethysmography (IPG) and Doppler ultrasonography (Doppler) are both non-invasive and, in patients with clinically suspected DVT, are sensitive and specific tests for proximal DVT. Both tests are relatively insensitive to calf DVT. IPG has the advantage of being an objective technique whereas Doppler is subjective and its accuracy may suffer in inexperienced hands. 125I fibrinogen leg scanning (leg scanning) is an inappropriate test when used alone in patients with clinically suspected DVT as it is insensitive in the upper thigh, may be negative in 30% of patients with established DVT and may take up to 72 hours to become positive. The combination, however, of IPG and leg scanning provides an accurate approach for the detection of both proximal and calf DVT in patients with established DVT. This approach is not associated with patient morbidity and offers the clinician an alternative to venography.