bluuebunny/crossref_metadata_2025_split huggingface dataset:
Circulating Platelet Aggregates In Thrombotic Pathologies
Authors: Rodzynek J J , Schoenfeld P L , Martin T , Léautaud P , Wettendorff P , Delcourt A 
Published: July 2018

The dosage of circulating platelet aggregates following Wu and Hoak (CPA) was performed in 52 healthy volunteers acting as normal controls (N), in 205 consecutive patients admitted in a general hospital for pathologies other than thrombotic or cardiac ischaemia (group I), in 59 consecutive admissions for deep venous thrombosis (group II), in 45 consecutive admissions for pulmonary thromboembolism (group III), in 35 consecutive admissions for acute coronary insufficiency (group IV) and in 73 consecutive admissions for acute myocardial infarction demonstrated by electrocardiogram and specific enzymes (group V). The percentage of positive tests (CPA 0.80) in those various groups appeared as follows: In conclusion: The positivity of CPA is not a specific indicator of a thrombotic disease neither of acute coronary insufficiency (36.5% false positive tests). CPA is not sensitive for the diagnosis of thrombotic conditions.In the setting of ischaemic heart disease, CPA positivity appears with higher frequency when myocardial necrosis is demonstrated, However the two groups don’t differ significantly on a statistical basis (P non significant).
Platelet Adhesion And Aggregation In Behcet’S Syndrome
Authors: Brook J G , Aviram M , Haim S , Markel A , Weiner A , Marmur A , Berkowits Y , Bornstein I , Youdim M 
Published: July 2018

Both venous and arterial thrombosis can be a feature in some patients with Behcet’s Syndrome. The pathogenesis of the coagulopathy is as yet ill understood. We have examined platelet adhesion and platelet aggregation in 14 patients with proven Behcet’s Syndrome and compared them with matched controls. Platelet adhesion was measured by two techniques recently developed in our laboratory. In the first platelet adhesion is determined when platelet rich plasma is applied to a glass slide while applying a predefined centrifugal force. In the second method citrated whole blood is pumped through an inert silicone tube and applied to a glass slide in the form of a stagnation point flow field. The number of platelets adhering to the slide per unit area is determined. The conditions of blood flow through this system were similar to those prevailing in arteries of similar size. Adhesion is found to be significantly greater in Behcet’s patients by both methods. There was a 30% increase in platelet adhesion in the Behcet patients. Platelet aggregation was determined by the Born method. Platelet rich plasma was used and 5HT, epinephrine, ADP, and collagen were the aggregating agents. In our hands platelets from the Behcet’s patients are more sensitive to aggregation induced by epinephrine and ADP than platelets from our controls.It appears that disturbed platelet function may play an important role in the coagulopathy of Behcet’s Syndrome.
Platelet Norepinephrine Fluxes In Normotensive Subjects And Essential Hypertensive Patients
Authors: Legrand C , Dubernard V , Meyer P 
Published: July 2018

Disturbed neuronal metabolism and storage of monoamines has been described in various experimental and human hypertensive diseases. Since blood platelets are considered as valid models of sympathetic neurons, the uptake and release of [3H] norepinephrine (NE) was investigated in platelets isolated from normal subjects and from patients having essential hypertension. In addition, the intracellular metabolism of [3H] -NE was followed by high performance liquid chromatography.In basal conditions, NE was found to be slowly incorporated into the platelets and approximately 25% of the absorbed radioactivity was recovered as a sulfoconjugate metabolite which is thought to represent the cytoplasmic form of the monoamine. The uptake of NE was inhibited by drugs known to interfere with the platelet serotonin accumulation at the plasma membrane level (chlorimipramine, ouabain) or at the vesicular storage level (tyramine, reserpine). In addition, drugs which impair the intravesicular storage of monoamines leading to their accumulation in the cytoplasm, induced a marked increase in platelet NE metabolism and release.The uptake of norepinephrine was slightly reduced in platelets from essential hypertensive patients. A marked increase in spontaneous NE release was measured in correlation with increased intracellular NE metabolism. The results are compatible with impaired intravesicular storage of the monoamine leading to increased diffusion through the plasma membrane.
Circulating “Empty” Platelets In Hemolytic Uremic Syndrome And Thrombotic Thrombocytopenic Purpura
Authors: Lüchters G , Budde U , Klehr U , Müller N 
Published: July 2018

In two patients (1 male, 1 female) the diagnosis of hemolytic uremic syndrome (HUS) and in one male patient the diagnosis of thrombotic thrombocytopenic purpura (TTP) was confirmed. All patients showed a platelet aggregating factor in plasma. PgI2-stimulating activity of patient’s plasma was defective or absent. Platelet count was low and platelet aggregation was severely impaired. Even with high amounts of ADP (20 μM) only first phase aggregation could be seen. Epinephrine induced aggregation was absent. The highest amount of collagen used (20 μg/ml) induced only a small aggregation and no ATP-secretion. Thrombin stimulated ATP-secretion was decreased while Ristocetin induced aggregation was normal. ATP- and ADP-content of platelets was low and ATP/ADP ratio was raised above the normal value. Platelet spreading was severely impaired.From these findings we conclude that at least part of the platelets in these related diseases are circulating “empty” platelets which underwent degranulation in the patient’s blood vessels.
Beta - ThrombogloBulin And HA - Platelet Factor 4 In Multiple Myeloma, Hodgkin Disease And Malig - Nant Lymphoma - Effects Of Therapy
Authors: Klingemann H G , Eqbrinq R , Havemann K 
Published: July 2018

Determination of platelet specific proteins Beta-Thromboglobulin ( β-TG) and High Affinity Platelet Factor 4 (PF 4) in plasma has been proved as useful marker for an enhanced release reaction in some diseases, mostly due to an in - creased platelet aggregation. To evaluate suit - able marker for a prethrombotic state in some myeloproliferative diseases ue investigated patients suffering from multiple myeloma, Hodgkin disease and malignant lymphoma. β- TG and PF 4 were measured in platelet poor plasma using RIA - kits (Amersham-Buchler / Abbott Labor.). In addition ue determined; platelet count, spontaneous and collagen induced platelet aggregation, the activity of AT III and of the clotting factors I, V, VIII, XIII and the concentration of FDP.RESULTS: Normal range was found to be 0-55 ng/ml forβ-TG and 0-12 ng/ml for PF 4. Both release proteins were increased in 17 out of 25 patients with myeloma, in 13 out of 15 patients with Hodgkin disease and in 10 out of 12 patients with malignant lymphoma. A correlation to the severity of the diseases were demonstrable. Chemotherapy caused a decrease of β -TG and PF 4 levels in some cases. However no correlation could be found between β- TG and PF 4 levels and in vitro tests of platelet aggregation. Further clotting assay provided evidence for an activation of clotting (like DIC) in a few patients. Other possibilities - like the release of the platelet specific proteins by immunocomplexes, prostaglandins or proteolytic enzymes from granulocytes must taken into account.
A Radioimmunoassay For The Quantitation Of Bovine Platelet Factor 4 And Its Use In Monitoring Artificial Heart Implants
Authors: Clark D M , Deneris J , Workman E F , Olsen D 
Published: July 2018

A radioimmunoassay for the quantitation of bovine platelet factor 4 (PF4) has been developed for use on bovine plasma. The assay utilizes classical radioimmunoassay techniques; 50λ of standard or plasma are mixed with 250λ 125I- bovine PF4 and 250λ goat anti-bovine PF4 for two hours at room temperature. Antibody-bound PF4 is separated from free PF4 by precipitation with ammonium sulfate. The resulting standard curve has a least detectable dose of 50 ng/ml, a 50% intercept around 400 ng/ml, a range of 01000 ng/ml and is unaffected by the presence of heparin in samples. Plasma samples are collected using a two-Vacu- tainer technique employing Thrombotect™ collection tubes (Abbott Laboratories) which have been developed to minimize any in vitro platelet release. The mean PF4 concentration of 7 healthy control calves was 55 ng/ml with a range of 0 to 180 ng/ml. PF4 levels were measured serially in calves which had undergone artificial heart implantation.In one calf with a pre-operative PF4 level of 99 ng/ml, the PF4 level increased to 638 ng/ml during post-surgical complications 7 days after surgery and subsequently decreased to 230 ng/ml after coumarin therapy 27 days after surgery. A similarly implanted calf without post-surgical complications had a pre-operative PF4 level of 180 ng/ml and a 20 day post-surgical level of 245 ng/ml. These data suggest that PF4 levels are elevated in post-surgical hypercoaguable states and that measuring PF4 provides a useful tool for monitoring the post-surgical patency of artificial surfaces such as prosthetic valves, artificial hearts, left ventricular assists and thoracic surgery in general. This program is under further investigation to increase the understanding of platelet involvement in such systems, to determine how long PF4 elevations exist prior tc the.onset of clinical symptoms and to follow the success or failure of anticoagulant therapies.
Modification Of The Haemostatic System By Atherogenic Diets In Rats
Authors: Badimon J J , Badimon L , Villaverde C A 
Published: July 2018

We have studied the haemostatic system and its modification due to different atherogenic diets in Sprague-Dawley rats. The diets administrated were an original previous ly described atherogenic model and its two constituent phases; a first phase of 3 days (hypervitaminic-D2) that produced calcic infiltration followed by a second one of 12 days (hyperlipidic) that induced lipid deposition.The hypervitaminic diet induced a highly significant (2p< 0.001) increase on triglycerides (TGL); the total-CHO/ HDL-CHO ratio decreased slightly. It induced a highly increase of the index of thrombodynamic potential (ITP) with out modification of fibrinolytic activity and fibrinolytic inhibitors.The hyperlipidic diet induced a highly significant increase (2p<0.001) of TGL, CHO and VLDL. The total-CHO/ HDL-CHO ratio decreased markedly (2p <0.001). This diet by itself did not produced vascular morphological lesions. It was obtained a slight increase in the ITP, a significant de crease in fibrinolytic activity of whole blood without modT fication of diluted blood fibrinolytic activity and an increase in the level of fibrinolytic inhibitors.The experimental model, arranged by the two phases consecutively given, induced a highly (2p<0.001) increase of CHO, TGL and VLDL. The total-CHO/HDL-CHO ratio decreased markedly (2p <0.001). The ITP was also increased; fibrinolytic activity of whole blood was diminished without modifica tion of diluted blood and fibrinolytic inhibitors were increased.Thus, this experimental model induced an atheroscle- ritic pattern with activation of the coagulation system, due to the hypervitaminic phase, and decrease of fibrinolytic activity and increase of fibrinolytic inhibition, due to the hyperlipidic phase.
Hemostatic Variables In A Group Of Traffic Police Men
Authors: Mandalaki T , Hatzakis A , Louizou C , Antonopoulou A , Vergi M , Polichronakis E , Trichopoulos D 
Published: July 2018

A study of various haemostasis parameters in a group of twenty-two traffic policemen working under special conditions, i.e. in locations of heavy traffic (5 hours shifts in the centre of Athens) is presented. These normal subjects (aged 22-39) are subjected to physical and psychological stress and to the effect of increased air pollution. Pretests were conducted before the beginning of the shift (6 a.m.) and postests were conducted at the end of the shift (12 noon).The following tests were performed: 1. Prothrombin Time (P.T.), 2. Activated Partial Thromboplastin Time (A.P.T.T.), 3. Fibrinogen, 4. Euglobulin Lysis Time (E.L.T.), 5. Fibrin Degradation Products (F.D.P.), 6. Platelets, 7. Platelet Aggregation by A.D.P., 8. PF4 9. F VIII:C, F VIII:Ag, F VIII:Rcof, 10. Antithrombin III (AT III).Results: Significant decrease of Fibrinogen, ELT and AT III, significant increase in APTT, FDP. Increase in PF4 levels. The results are indicative of the occurence of an activation of the fibrinolytic mechanism after the shift with signs of consumption of certain coagulation factors. There is an adverse effect on the hemostatic balance of traffic policemen during their service.
Influence Of Yoga Or Blood Coagulation
Authors: Chohan I S , Nayar H S , Thomas P , Geetha N S 
Published: July 2018

Yoga,an ancient Indian cult,is knovn to endow one with perfect physical,mental and spiritual health. Its effect on blood coagulation is not known. A pilot study was conducted, Seven adult males underwent a combination of yogic exercises, daily one hour,for 4 months. Parameters of blood coagulation were estimated before commencement of yoga and then repeated at the end of training. These included: haemoglobin(Hb) gm/dl,haematocrit (Hct), blood platelet counts in thousands/cu mm, activated partial thromboplastin time(APTT) sec, platelet aggregation time(FAT) sec, fibrinogen mg/dl, and euglobulin fibrinolytic activityfFA) measured as area of lysis in sq mm. Final results were compared with the initial ones. All values are expressed as Mean ± SEM.Following yoga, Hb Showed a significant rise from 13.5 ±;, 0.1 to 14.5 ± 0.3 and so did Hct from 44.5 ± 1.1 to 49.3 ± 1.2. FA increased significantly from 271 ± 36 to 443 ± 6 4, it was accompanied by a fall in fibrinogen from 2 54± 17 to 202 ± 10. APTT prolonged from 16.4 ± 0.2 to 17.4 ± 0.7 and so did PAT from 3 3 .O ± 3 .? to 40.1 ± 9.75 though differences here were not significant. Blood platelet counts showed a marginal but significant rise from 336.6 ± 26.3 to 391.6 ± 10.0.This study suggests that yoga induces a state of hypocoagulability evident by raised FA,fall in fibrinogen,suppressed platelet activity and low levels of activated clotting factors. Yogic exercises,therefore,may be instituted for prevention of cardiovascular and thrombotic disorders in man. Benefits of yoga seem to accrue from oarasympathodominance and symnathetic quiescence of the autonomic nervous system brought about by yoga.
Quantitation of the Coagulation Inhibition in Vivo Due to Breakdown Products of Fibrin
Authors: Mitchell P. S , Beller F. K 
Published: July 2018

SummaryDegradation products of human fibrinogen were prepared by in vitro lysis of fibrin clots by urokinase activation and injected into rabbits on a quantitative basis. The dose necessary to anticoagulate the animal was equal to 2½ to 3 times the animals’ fibrinogen level. The effect on whole blood clotting time and thrombin time lasted for approximately 2 hrs. The “r” time of the TEG returned to normal after 1 hr while the “Max” value remained abnormal for more than 120 min. Degradation product E was shown to clear more rapidly than D by immunochemical techniques. The overall T ½ clearance was found to be approximately 12 hrs.
Effects of Trans-4-Aminomethylcyclohexane Carboxylic Acid as an Antifibrinolytic Agent on Arterial Wall and Experimental Atherosclerotic Lesions in Rabbits
Authors: Kato N , Morimatsu M , Tanaka K , Horie A 
Published: July 2018

SummaryEffects of trans-4-aminomethylcyclohexane carboxylic acid (t-AMCHA) as an antifibrinolytic agent on the experimental arteriosclerosis produced by cholesterol feeding and on the experimental thromboembolism induced by autogenous fibrin clot injection were observed in rabbits. Effect of inhibited fibrinolysis on the arterial wall itself was also observed.Administration of 500 mg/kg body weight of t-AMCHA highly inhibited the lysis time of serum, but there was no influence on the plasma fibrinogen level.There was no significant difference in the cholesterol level, sudanophilia of the aorta and the accumulation of foam cells in the aorta and pulmonary arteries between t-AMCHA + cholesterol group and cholesterol group.Edema in the subendothelial layer of the aorta and elastic pulmonary artery, proliferation and swelling of the endothelial cells, and edema of the subendothelial layer of large muscular pulmonary arteries were increased in the incidence and severity in t-AMCHA treated animals. Localized intimai fibrous thickening was found in large muscular artery in t-AMCHA treated animals. Small fibrin thrombi and angitis were rarely found in muscular pulmonary artery in t-AMCHA treated animals.Fibrinolytic activity of blood and dissolution of clots in the pulmonary arteries were depressed by t-AMCHA treatment in the animals injected autogenous fibrin clots, while the inflammatory reaction in the arterial wall was less severe as compared with that of untreated animals.It was reasonable to presume that the inhibition of fibrinolysis would promote the development of atherosclerosis through its influence on the fibrin dissolution on and in the arterial wall, and on the vascular permeability of the arterial wall.
Effets du Sodium et du Calcium sur la Conversion du Fibrinogène en Fibrine
Authors: Marguerie G , Hudry G , Hollard G 
Published: July 2018

RésuméUne méthode simple est décrite pour étudier l’effet de la force ionique sur la transformation de fibrinogène en fibrine. L’influence du Sodium et du Calcium a été étudiée. Nos résultats semblent montrer que l’augmentation de la concentration en sel affecte la polymérisation des monomères de fibrine. Un effet particulier du calcium est discuté.
Protection by Aspirin against Experimentally Induced Arterial Thrombosis in Dogs
Authors: Danese C. A , Voleti Ch D. , Weiss H. J 
Published: July 2018

SummaryThe possible anti-thrombotic properties of drugs which interfere with platelet aggregation were studied. Segments of the peripheral arteries of dogs were isolated, injured either by endarterectomy or chemically by instillation of 0.1 N H2 S04 (chemical injury). Two days later, the segments were examined for the presence of thrombosis. In animals which received only a placebo, 29% of the chemically-injured segments and 43% of the endarterectomized segments became totally occluded with thrombi. Treatment with aspirin (600 mg per day) reduced this incidence to 2 and 11% respectively (p < .05) while treatment with dipyridamole (DPM) (200 mg per day) had no effect. In a second study, aspirin ingestion reduced the incidence of total occlusion in chemically-injured segments from 38 to 0%. Connective-tissue induced platelet aggregation decreased in aspirin treated animals, while DPM had no effect. The findings support previous suggestions that aspirin, perhaps by inhibiting platelet aggregation, has anti-thrombotic properties.
The Coagulability of Partially Lysed Fibrinogen Effect of pH and Ionic Strength
Authors: Triantaphyllopoulos D. C , Torres Mary 
Published: July 2018

SummaryAddition of thrombin to plasma obtained from dogs injected with plasmin clotted more fibrinogen when the plasma was diluted with saline than when it was diluted with distilled water. In contrast, more fibrin was formed in dilutions with distilled water when thrombin was added to intact plasma obtained prior to the injection of plasmin.The same phenomenon was observed with purified human fibrinogen submitted to limited digestion with plasmin and was found to be pH dependent. When the pH was greater than 7.3 more fibrin was formed if the fibrinogen was diluted with saline than if it was diluted with distilled water. The opposite was observed at pH values lower than 7.2.Similar results were obtained with the fraction of partially lysed human fibrinogen which precipitates at 25% saturation with ammonium sulfate. The same fraction, however, obtained from partially digested bovine fibrinogen did not react exactly the same way. In dilutions with distilled water there was an inverse relationship between the pH value and the amount of protein which clotted; but the reverse did not apply to the same extent in dilutions with saline.At variance to the above observations the clottability of purified intact fibrinogen was not significantly altered by changes in pH or in ionic strength.The clottability of partially lysed human plasma could be reversed (more fibrin in distilled water than in saline) after exhaustive dialysis against oxalated (pH 7.0) but not against citrated (pH 7.8) saline indicating that the change in clottability was due to a change in pH.
Concentration of Platelet Cofactor I (Factor VIII) from Bovine Serum*
Authors: Mammen Eberhard F 
Published: July 2018

SummaryA method for obtaining concentrates of platelet cofactor I (factor VIII) from ether extracted bovine serum has been developed. Platelet cofactor I is inactivated during the coagulation process by undergoing a complex formation, which is broken by ether extraction.In each of 13 preparations from 1,000 ml of extracted serum an average total activity of 3,055 platelet cofactor I units was isolated. The specific activity was 4,760 units per milligram tyrosine and 138 units per milligram protein (Biuret.)In the paper electrophoresis the fractions were homogeneous. Using immunoelectrophoretic techniques three bands were found against anti-bovine serum from rabbits. The preparations activated purified prothrombin in the presence of platelets, Ac-globulin and calcium ions. They substituted in the thromboplastin generation test for adsorbed plasma and corrected the delayed thromboplastin generation of hemophilia A plasma. They also corrected the prolonged recalcification times of hemophilia A plasma. The preparations lost their activity upon storage at room temperature and in the icebox rapidly. Also freeze drying resulted in a complete loss of activity.
Hypercephalinemia and Experimental Venous Thrombosis in the Rat
Authors: Nordöy Arne F 
Published: July 2018

Summary and ConclusionNine, 18 and 36 mg per kg body weight of a crude cephalin prepared from rat brain were suspended in saline and injected intraperitoneally in rats. The influence on coagulation, platelet adhesiveness, antifibrinolytic activity and incidence of experimental venous thrombosis was studied.The following observations were made:1. The recalcification time of plasma was shortened maximally one hour after the injection, with gradual return to normal values. Normal recalcification time was obtained 24 hours after the injection of the lowest dose, whereas it was still slightly shortened after the higher doses.2. The number of adhesive platelets increased, whereas no antifibrinolytic activity was found.3. An increased incidence of experimental venous thrombosis was observed.Thus, there seems to be a relation between increased platelet adhesiveness, accelerated recalcification time and the tendency to venous thrombosis.
Activated Human Hageman Factor (XII)*
Authors: Speer R. J , Ridgway Helen , Hill J. M 
Published: July 2018

SummaryAn improved method for the isolation of highly purified active human Hageman factor has been described. An overall recovery of 25% with a purification of 106 has been achieved. Certain of the physical and chemical characteristics of XII have been elucidated. Selective chemical modification of functional groups and a variety of enzymatic assays have been employed in an effort to shed light on the mechanism of action of this procoagulant.