bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aggregation of Platelet Membrane Vesicles by ADP
Authors: Watanabe K. , Yamamoto M. , Ando Y. , Ikeda Y. , Toyama K. , Deguchi N. 
Published: May 2019

The study was performed to examine biochemical and biophysical changes in platelet membrane vesicles(PMV) when aggregated by ADP. PMV was isolated from normal donors by using glycerol lysis technique, and was suspended in 10mM Tris, 0.15M NaCl buffer, pH 7,4. Aggregation of PMV was readily observed under phasecontrastmlcroscopy within 3 min after addition of ADP(5mM), while AMP, UDF or GDP was without effect. Light scattering Intensity of PMV suspension determined by Lasernepherometer increased with addition of ADPCJmM), reaching plateau within 2 to 3 min, also indicating that vesicles were rapidly aggregating in suspending medium. In electronmicroscopic observation, amorphous floccuent materials were seen between aggregated PMV by ADP. This PMV aggregation by ADP was inhibited by the treatment of PMV with either neuraminidase(0.1u/ml) or trypsin(20μg/ml) and was hardly observed in PMV from a patient with thrombasthenia.The addition of ADF(10mM) to PMV suspension resulted in the reduction in electronhoretic mobility of PW(0.301±0.057μ·cm/sec·V, control ;1.194±0.037) and increase in membrane microviscositv (p value; 0.277, control; 0.255).Changes in protein profiles in aggregated PMV were examined by SDS Polyacrylamide gel disc electrophoresis. One protein band(M.W. 200,000) disappeared and instead, there observed increased coomassie blue staining intensity at the top of the gel.The results suggest that these biochemical and biophysical changes in PMV may in part explain the mechanisms of platelet aggregation By ADP.
Heparin-Affinity of Antithrombin III in a Family With Congenital Antithrombin III Deficiency
Authors: Sas G. , Bánhegyi D. , Petö I. 
Published: May 2019

We found a new thrombophilic family with antithrombin III/ AT-III / deficiency. In the members of this family both immunologic and functional methods revealed similarly decreased levels of AT-III. Gelfiltration displayed identical size of AT-III molecule of patient and normal alike. On the basis of tnese findings we assumed that in this family normal AT-III is produced Dut only in diminished quantity. Experiments on the heparin-affinity of AT-III did not support this assumption. The AT-III of the proposita migrated slower than that of normal person in the heparinized agarose gel. In the course of the heparin-affinity chromatography the AT-III of the proposita could be eluted at lower salt concentrations than normal AT-III.Thus we conclude that even in the case of “true” AT-III deficiency the molecule might have some qualitative deviation from normal.
Thrombasthenia: A Model for Studying Platelet Activation in the Absence of Aggregation
Authors: Levy-Toledano S. , Maclouf J. , Hardisty R.M. , Caen J.P. 
Published: May 2019

In response to the ionophore A 23 187, thrombasthenic platelets undergo normal shape charge, serotonin release and metabolism of 14C-arachidonic acid (including liberation from prelabelled platelet phospholipids and conversion to thromboxane B2 and HETE). These responses, using either PRP or washed platelets, are accompanied by a characteristic optical density (OD) change in the absence of aggregation. This change was associated with the formation of a central contractile gel mass and central apposition of organelles, but lactic dehydrogenase determinations showed no evidence of platelet lysis. These reisuits can be mimicked by stirring A 23 187 with normal platelets in the presence of EOTA or EGTA. The OD change in this system was inhibited by chlorpromazine, propranolol and other drugs which interfere with membrane transport of Ca2+ but not by colchicine, cyto-, chalasin B, prostaglandin Ej, creatine phosphate/creatine Phosphokinase or antimycin and deoxyglucose.These findings show that the action of ionophore on thrombasthenic platelets provides a model for dissociating platelet thromboxane formation, contraction and secretion, all of which are dependent on intracellular calcium shifts, from aggregation, for which extracellular calcium is required; they suggest that the underlying membrane glycoprotein abnormality in thrombasthenia may result in a failure to react with extracellular calcium.
Removal of Potentially Thrombogenic Material from a Concentrate of Factors II, IX & X by Polyethylene Glycol Precipitation
Authors: Foster P. R. , Patterson M. R. , Johnson A. J. , Middleton S. M. 
Published: May 2019

Polyethylene glycol(PEG) precipitation has beer used for the removal of hepatitis B surface antigen (HBsAg) from a concentrate of factors II, IX & X of intermediate purity. HBsAg is precipitated into a fraction PI at 20% (w/v) PEG and pH 6.5 while factors II, IX & X remaining in the supernatant are subsequently precipitated at 30% (w/v) PEG and pH. 5.2These various fractions have been assessed for the presence of potentially thrombogenic materials by in vitro tests. In comparison with the starting material the precipitate rich In factors II, IX & X has a significantly increased non-activated partial thromboplastin time (NAPTT) and a decreased rate of factor Xa generation. By contrast the waste fraction (PI) exhibits a significantly decreased NAPTT and an increased rate of factor Xa generation suggesting that potentially thrombogenic material has been selectively precipitated. This procedure has been used to prepare a factor II, IX & X concentrate containing 100 U FIX/ml with reduced contamination by both HBsAg and thrombogenic materials.
Inhibitory Activity of Foy on Thrombin and Activated Factor X.
Authors: Kōsakl G. , Ohno H. , Imaoka S. , Hirata F. 
Published: May 2019

When hypercoagulable state prolongs, DIC will develop regardless of the presence of naturally circulating anticoagulants. And heparin has been used In order to reinforce them in the treatment and prevention of DIC. The mechanism of anticoagulant action of FOY [Ethyl-p-(6-guanldlnohexanoyloxy)benzoate methanesulfonate] was Investigated, since It was reported that it has anticoagulant activity and that it is very effective in the treatment of DIC.POY was found to possess inhibitory effect on hydrolytic activity of thrombin on synthetic substrate as well as that of activated factor X, plasmin and plasma kallikrein. The mode of action was competitive and the strongest inhibition was against plasma kallikrein (Ki:0.2μM), secondly to thrombin(0.97μM), thirdly to plasmln(1.6μM) and then to activated factor X(8.5μM), judging from their Ki values. The inhibitory effect of FOY in coagulant activity of thrombin on fibrinogen was stronger than that against fibrlnolyi » activity of plasmin. Synergetic effect of FOY with AT III was then studied. FOY was found to inhibit residual activity of thrombin or activated factor X which was not neutralized by AT III and heparin. It was postulated that the inhibitory action of FOY was not affected by the presence of AT III and heparin, since Km values of thrombin and activated factor X and Ki value of FOY were not altered in the oresence of AT III and heoarin.
Complement-Dependent Platelet Agglutination and Lysis of Rabbit Platelets by Endotoxin
Authors: Heinrich D. , Müller-Berghaus G. 
Published: May 2019

The effect of bacterial endotoxin on platelets from normal rabbits (NoR) and C6-deficient rabbits (C6defR) was studied. Platelets were washed, labeled with 14C-serotonin and 51chromium and resuspended in Tyrode/albumin (TA), normal rabbit plasma (NoP) or C6-deficient rabbit plasma (C6defR). When incubated with endotoxin (final conc. 100-200 ug/ml) the following results were obtained:Conclusion: To induce platelet agglutination by endotoxin alternate pathway complement activation up to C3/5 is necessary. Complement activation of C6-9 results in 14C-serotonin release and platelet lysisSupported by the Deutsche Forschungsgemeinschaft
Resistance to Atherosclerosis in Pigs with Cenetic and Therapeutic Inhibition of Platelet Function
Authors: Fuster V. , Fass D.N. , Bowie E.J.W. 
Published: May 2019

Platelets appear to play an important role in the development of atherosclerosis. Accordingly, we have investigated whether pigs with genetically impaired platelet function in the form of homozygous von Willebrand’s (vW) disease and normal pigs treated with the platelet inhibitors Dipyridamole (6 mgs/kg/day) plus Aspirin (15 mgs/kg/day) (D+A) are resistant to atherosclerosis when compared with normal control pigs matched by breed and weight. The three groups of pigs received a high (2%) cholesterol diet from age 3 to 9 months and then quantitation of the fibrous atherosclerotic plaques was performed in the distal third of the aortas since in pigs this is the region prone to the development of lesions.
Normal pigs. Of 11 pigs, 8 (73%) had significant plaques involving more than 10% of the aortic surface (mean surface 18%), Homozygous vW pigs. Of 7 pigs, only 1 (14%) had a small plaque (surface 3%) (p<0.01 rank≤test). Normal pigs treated with D+A. Of 7 pigs, only 1 (14%) had significant plaques (mean surface 8%) (p< 0.05 rank≤test).These findings suggest a resistance to the development of atherosclerosis In pigs with genetic and therapeutic inhibition of platelet function.
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.
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
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.
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.
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.
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
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
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.
Protein Concentration Dependence of Calcium Binding to Prothrombin Fragment-1
Authors: Brenckle G. M. , Peng C. W. , Jackson C.M. 
Published: May 2019

Calcium binds to prothrombin and prothrombin fragment-1 with apparent positive cooperativity. It has previously been suggested that the cooperativity is induced by a conformation change in the protein. Another process which can induce cooperativity is ligand induced self-association. Calcium has been shown to induce dimerization in prothrombin and fragment-1. If such an intermolecular process is responsible for the apparent cooperativity, the calcium binding should become non-cooperative at the limit of zero protein concentration. The protein concentration dependence of calcium binding to fragment-1 was investigated using ultraviolet difference spectroscopy and the Hummel-Dryer equilibrium binding technique. A maximum of 10 sites was found on fragment-1 at high calcium concentration (10 μM). The maximum in the Scatchard plot was observed to decrease at fragment-l concentrations less than 10 μM. The difference spectral data was analyzed utilizing the equilibrium binding data. The apparent dissociation constant ob tained from difference spectral titrations is protein concentration dependent. At low protein concentration (1-2 μM) the maximal spectral change occurs with 2 or less Caions bound, while at higher concentrations (50-100 μM), the maximum is reached after ~5 sites are filled.(Supported by HL14l47, Specialized Center of Research on Thrombosis, NHLBI).