bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Method for Plasminogen Standardization
Authors: Gajewski J , Markus G 
Published: June 2018

SummaryA method for the standardization of human plasminogen is proposed, based on the stoichiometric interaction between plasminogen and streptokinase, resulting in inhibition of proteolytic activity. Activation of a constant amount of plasminogen with increasing amounts of streptokinase yields linearly decreasing activities, as a function of streptokinase, with a sharp transition to a constant residual level. The point of transition corresponds to complete saturation of plasmin with streptokinase in a 1:1 molar ratio, and is therefore a measure of the amount of plasminogen present initially, in terms of streptokinase equivalents. The equivalence point is independent of the kind of protein substrate used, buffer, pH, length of digestion and, within limits, temperature. The method, therefore, is not subject to the variations commonly encountered in the usual determination based on specific activity measurements.
Assay of the Antifibrinolytic Activity in Human Plasma by Means of the Lysis Time Method
Authors: Ygge J , Berg W , Korsan-Bengtsen K 
Published: June 2018

SummaryA one-stage lysis time method to determine the total antifibrinolytic activity of human plasma is described. Purified fibrinogen, thrombin, plasminogen, and urokinase were used in the test system. The necessity of using a high plasminogen concentration compared with the urokinase concentration is pointed out. The concentration of the reagents has to be carefully standardized.A straight line will be obtained in a semi-logarithmic system when plasma dilutions are plotted against.

The validity of this relation is investigated when the concentrations of plasminogen, fibrinogen, and urokinase are varied. It is also shown that this relation is valied when the antifibrinolytic activity is increased postoperatively and after delivery.The antifibrinolytic activity is expressed as a percentage of the activity of a standard plasma. The standard plasma does not change its antifibrinolytic activity during storage at —20° C for at least three months.The error of the method is about 2%.Finally, the present report includes an experiment, the result of which makes it probable that the main action of plasma tested in this one-stage lysis time system is an antiplasmin activity.
Initial Studies of a Potent Antiheparin Agent (Ubiquin®)
Authors: Goodsell E. B , Krause R. A , Kimura E. T 
Published: June 2018

SummaryUbiquin (oligo-3-(N-methylmorpholinium)-l,2-propylene oxide chloride) is a stable, water soluble, active heparin antagonist producing prompt neutralization when administered in a 1:1 ratio to rats and dogs. Initial studies indicate that it is devoid of any effect on coagulation per se; nor are there any obvious side effects manifested during the process of neutralization. The acute toxicity is less than that of other compounds in use: toluidine blue, protamine and hexadimethrine.
Absent Plasma Second Phase Platelet Aggregation Factor in a Patient with Hageman Trait
Authors: Okonkwo P , Post R , Sise H 
Published: June 2018

SummaryA case is described of a patient with factor XII deficiency in whom the second phase of platelet aggregation was missing after addition of ADP to platelet rich plasma. There was very little aggregation on addition of epinephrine, collagen or thrombin. Clot retraction was absent, but all other platelet functions were normal and there was a very minor bleeding tendency. The defect was corrected by normal platelet poor plasma and was found to be due to a missing cofactor of platelet aggregation normally found in fraction 1–0. The defect could be distinguished from that seen in subjects ingesting aspirin as well as from the defect seen in patients with a long bleeding time, defective platelet aggregation with ADP, epinephrine and collagen at low concentrations, no correction by addition of normal platelet poor plasma, and a history of mild bleeding disorder. It is thought that this defect may exist in otherwise normal individuals and that attention in this case was called to it by the presence of the deficiency of factor XII. It could be conclusively shown that factor XII is not necessary for normal platelet aggregation.
Factor XII Defect and Hemorrhage Evidence for a New Type of Hereditary Hemostatic Disorder
Authors: Egeberg O 
Published: June 2018

SummaryIn some members of 4 Norwegian families, a slight to moderate bleeding tendency was found to be associated with a partial blood factor XII defect, the factor activity about half of average normal level. In keeping with the low factor XII, surface activation rate of factor VII in plasma was found significantly decreased.The disorder seems to be transmitted as an autosomal intermediately dominant trait.A high incidence of cerebral apoplexy was recorded in the patients, and the first cerebrovascular attack had in most affected patients occurred at a relatively early age.In some of the patients attacks of localized edema, severe headache and abdominal pain, and different types of allergy remind of the problems of the demonstrated non-coagulation properties of factor XII.The results are discussed.
New Families with Factor XII Deficiency
Authors: Egeberg O 
Published: June 2018

SummaryHereditary factor XII deficiency is reported in 2 unrelated Norwegian families.Case 1 was a 50 year old female, who was investigated because of a subcutaneous hematoma of unexplained cause. She had bruised easily, but neither she nor members of her family had suffered from definite and marked bleeding tendency. In the last years she had had hemoptyses of unknown cause. Five years ago she had a slight cerebral vascular episode with temporary hemiparesis in extremities. A sister had died 46 year old in cerebral apoplexy. The parents were first cousins.Case 2 was a 72 year old male. He had no definite history of bleeding tendency, neither had members of his family. He suffered from diabetes, hypertension and vascular encephalopathy. After the age of 67 he had several attacks of cerebral apoplexy with paresis of extremities, ataxia and parkinsonism.Blood factor XII was for both case 1 and case 2 found lower than 1% of normal average, while other coagulation factors were in the main normal. A probable partial factor XII deficiency was demonstrated in some of the relatives of case 1 and case 2, consistent with the hypothesis that the principal patients were homozygous for their coagulation abnormality.The study lends some support to a hypothesis that a factor XII defect might contribute to a hemostatic disorder, and especially to an increased risk for cerebral apoplexy.
Fibrinogen Recovery in Fibrinolytic Dogs
Authors: Dulock M. A , Kolmen S. N 
Published: June 2018

SummaryHypoprothrombinemic dogs with or without a superimposed hypofibrinogenemia were allowed to recover spontaneously or under the influence of vitamin K. The hypoprothrombinemic status was corrected more rapidly in K-treated animals irrespective of the fibrinogenemic status.Hypofibrinogenemic dogs, irrespective of supplemental vitamin K, showed a biphasic rate of recovery. The initial phase was accelerated when vitamin K was administered, the second phase was not altered by vitamin therapy.It is suggested that vitamin K influence fibrinogen recovery in a manner analogous to its influence on prothrombin recovery; namely, “finalization” of precursor protein and accelerated release of the protein into the circulating fluid compartments.
Protection by Catatoxic Steroids against Phenindione Overdosage*
Authors: Selye H 
Published: June 2018

SummaryIn rats the severe and often fatal hemorrhagic diathesis induced by phenindione overdosage can be prevented by various catatoxic steroids such as ethylestrenol, SC-11927, spironolactone, norbolethone and oxandrolone. Conversely, steroids previously shown to possess no catatoxic potency in other test systems offer little or no protection against phenindione intoxication.
Inhibition of Platelet Aggregation by Dialysable Fibrinogen Degradation Products (FDP)
Authors: Stachurska Jolanta , Latałło Z , Kopeć Maria 
Published: June 2018

SummaryDuring prolonged proteolysis of fibrinogen by plasmin dialysable, low molecular fragments accumulate which inhibit platelet aggregation induced by thrombin, ADP, adrenaline and noradrenaline. These fragments isolated by dialysis were separated on sephadex G-25 column. The active component has probably a molecular weight lower than 5,000 and does not contain aromatic amino acids.
Platelet Reactions and Immune Processes
Authors: Jobin F , Tremblay France , Morissette M 
Published: June 2018

SummaryWe have studied the effect of chymotrypsin substrates and inhibitors on the aggregation of human platelets by collagen, latex, and epinephrine :1. We have found that platelet aggregation was inhibited by most chymotrypsin substrates and inhibitors which we studied.2. In general, there was a positive correlation between the effectiveness of the compounds as chymotrypsin substrates or inhibitors on one hand, and as platelet aggregation inhibitors on the other hand. However aromatic amino acid derivatives acetylated on the α-amine group were much less effective with platelets than they are with chymotrypsin.3. Chymotrypsin substrates and inhibitors also inhibit the anaphylactic release of histamine. The view is presented that the platelet release reaction and the mast cell release reaction have several common biological and biochemical features.4. The possible role of platelet esterases in platelet thrombogenetic reactions is discussed in the light of the present knowledge of the role of cell bound esterase in several inflammatory or immune cellular processes.
Amino Acid Transport into Human Platelets and Subsequent Incorporation into Protein
Authors: Cooper I. A , Firkin B. G 
Published: June 2018

SummaryHuman platelets are known to contain various protein components. Among them are fibrinogen and other soluble proteins. The origin of such proteins has not been clear.Studies were designed to demonstrate the ability of the platelet to incorporate amino acids and subsequently utilise these for de novo protein synthesis.Seven different 14C labelled amino acids were used, cysteine, lysine, serine, glutamic acid, proline, valine und leucine.Active incorporation into platelets of all these amino acids was demonstrated with some evidence for incorporation of cysteine, lysine and serine into the fibrinogen and soluble protein.
The Effect of Adenosine Monophosphate, Arcaine and Anti-Inflammatory Agents on Thrombosis and Platelet Function in Rabbits
Authors: Peterson Jane , Zucker Marjorie B. 
Published: June 2018

SummaryThrombi were produced by exposing femoral veins of rabbits to sodium morrhuate followed by partial ligation. The incidence of occlusive thrombosis in 30 min was 95% in animals with or without the infusion of 50-60 ml isotonic saline/kg body weight in 1½–2½ hrs. Comparable infusion of 0.04 M adenosine monophosphate reduced the incidence to 53% (p < 0.01). Arcaine was ineffective even at a toxic concentration. Injection of up to 180 mg phenylbutazone, 25 mg sodium salicylate, or 8.5 mg acetylsalicylic acid (ASA) per kg did not affect the incidence of occlusive thrombosis, but from 15 to 100 mg ASA per kg reduced the incidence to 46% (p < 0.01). Suspensions of connective tissue or collagen particles caused somewhat greater release of platelet-bound 14C-serotonin in heparinized than in citrated, platelet-rich rabbit plasma, and ASA more readily inhibited connective tissue- or collagen-induced aggregation in the latter. With varying connective tissue concentrations, this drug caused a constant reduction in the amount of 14C-serotonin released from the platelets in citrated, platelet-rich rabbit plasma, whereas considerably greater inhibition was observed in many samples of citrated, platelet-rich human plasma.
Quantitative Determination of Plasminogen
Authors: Bruhn H. D , Müller L , Duckert F 
Published: June 2018

SummaryA modification of the caseinolytic assay for plasminogen is described. This assay system is characterized by the following features :1. Urokinase is used as activator achieving a complete activation of the plasminogen whereas with streptokinase caseinolytically inactive plasminogen-activator complexes are formed.2. All incubation times are reduced to the minimum which is still compatible with accuracy.3. Results are expressed in percent of a standard of ten normal plasmas.4. In this two-stage assay-system (activation of plasminogen to plasmin, digestion of casein by plasmin) both stages proceed simultaneously in the same system, thus the plasmin formed is stabilized “in statu nascendi” by the casein.5. Several conditions (stability of plasminogen in frozen plasma, use of anticoagulants, reproducibility) are defined.
A Fixation-Shadowing Technique for Electron Microscopic Visualization of Platelets, Subcellular Material, and Fibrin
Authors: Stewart G. J 
Published: June 2018

SummaryPlasma components were visualized in three-dimensional detail by a method which depends on attaching plasma components, including platelets and fibrin, to a siliconized surface where they can be fixed, dehydrated and shadowed. Citrated PRP and blood contained a mixed population of discoid and dendritic platelets. Discoid platelets were thin with gently changing elevations and depressions on their surfaces. Dendritic platelets exhibited a random number and arrangement of dendritis. The “bodies” of dendritic platelets appeared to be thicker than discoid platelets. After thrombin action, the “bodies” from which dendrites radiated resembled various irregularly shaped geometric forms whose thickness was approximately equal to their width. Continued thrombin action caused disintegration of platelet membranes.Fibrinogen could not be resolved. However, after thrombin action, extensive polymerization of fibrin monomers into protofibrils about 130 Å wide was observed well before appreciable lateral or vertical polymerization had occurred. Later, large strands with frequent points of Y-type branching were common.The method has clinical potential since the entire procedure is simple and can be completed in less than an hour.
Changes in the Ultrastructure and Number of Platelets Induced by an Adrenochrome Complex
Authors: Stewart G. J 
Published: June 2018

SummaryAdrenochrome semicarbazone injected intramuscularly into apparently healthy human volunteers resulted in a decrease in the number of circulating platelets after 30 min. The decrease ranged from 9 to 44% with an average of 24%. The platelet count returned to near normal by 60 min. A similar concentration had no effect in vitro. The sodium salicylate carrier used to solubilize the adrenochrome complex had no effect on platelet numbers in vivo or in vitro.
Blood taken 30 min post injection and prepared by a fixation-shadow cast technique contained many disintegrating platelets and a high concentration of membrane fragments and free organelles. Thin sections of platelets revealed extensive intracellular alteration, but physically intact limiting membranes. Many free vesicles of various sizes and shapes and a few free mitochondria were shown in cross section.Two major metabolites isolated from human urine after adrenochrome semicarbazone injection caused platelet disruption when added to citrated PRP in vitro. The disruption was reflected by a decrease in the number of platelets and by the electron microscopic appearance of fixed-shadow cast preparations.It is suggested that the sequence of events observed in this study may represent, greatly exaggerated, a process which occurs in the body constantly as a small amount of epinephrine seems to be metabolized through an adrenochrome pathway.
Prostaglandins and Platelet Aggregation in Vivo
Authors: Kloeze J 
Published: June 2018

SummaryProstaglandins E1 and ω-homo-E1 which were shown previously to inhibit adenosine diphosphate (ADP)-induced platelet aggregation in vitro have now been found to inhibit this process also in vivo. Both prostaglandins inhibit transient thrombocytopenia induced by intravenous injection of ADP; PGE1 increases also the LD 50 of ADP when injected in high amounts into young rats. In both cases platelet aggregation in vivo is the primary cause of the phenomena observed.The symptoms observed on overdosing ADP by intravenous injection are unconsciousness within 10-20 sec after completion of the injection immediately followed by respiratory arrest and eventual death of the animal, generally within 10 min. It seems that blocking of the supply of blood to the brain by platelet thrombi, which on histological examination were found to occlude blood vessels in different organs, is the most important causative factor of the symptoms observed.
Laboratory Control of Oral Anticoagulants
Authors: Loeliger E. A , Meuwisse-Braun J. B , Muis H , Buitendijk F. J. J , Veltkamp J. J , Hemker H. C 
Published: June 2018

SummaryThe therapeutic range in oral anticoagulation, which is defined as the range of hypocoagulability resulting in optimal thrombosis prophylaxis and an acceptable bleeding tendency, is monitored by assay procedures of which the majority are modifications of Quick’s original prothrombin time test. With respect to individual patients on stabilized anticoagulation, the different modifications commonly used give the same information, the reliability depending more on the accuracy than on the sensitivity of the tests. The results do not appear to be comparable in terms of conventional reference curves or prolongation ratios of the coagulation times found, but on the basis of painstakingly defined normal and patient plasma, the mean of the factor II and factor X activity present in patients’ plasma proved to be a useful common denominator. In terms of this common denominator, the therapeutic range to be aimed at lies between (8 to) 10 and 20(to 25)percent.
Coagulation Findings in Rats with Experimental Hypersplenism and Their Changes after Splenectomy and after Administration of Adrenaline
Authors: Pudlák P , Farská I , Brabec V , Pospíšilová V 
Published: June 2018

Summary1. The following coagulation changes were found in rats with experimental hypersplenism: a mild prolongation of the recalcification time, shortened times in Quick’s test, a lowered activity in plasma thrombin time and shortened times in the partial thromboplastin test. Concentrations of factor II, V, VII (+X), VIII and X did not differ from those of normal control rats.2. The administration of adrenaline to hypersplenic rats induced the correction of the partial thromboplastin test, Quick’s test and plasma thrombin time to normal values. Concentrations of coagulation factors were not significantly changed. An increase was found in factor V.3. Splenectomy performed in hypersplenic rats was followed by a shortened recalcification time, a prolongation of the partial thromboplastin test and of the test with partial thromboplastin and kaolin. A prolongation was also observed in Quick’s test. Complete correction of plasma thrombin time was not observed. The concentration of factor VII increased.4. The administration of adrenaline to splenectomized rats with experimental hypersplenism did not induce any significant changes with the exception of a corrected plasma thrombin time and a decreased concentration of factor VIII.5. A different reaction of factor VIII to adrenaline in normal and hypersplenic rats is pointed out.
A Machine for the Determination of the Whole Blood Clotting Time
Authors: Watt D. L 
Published: June 2018

SummaryThe whole blood clotting time in glass tubes is widely used for the control of heparin therapy. In the investigation of coagulation disorders the whole blood clotting time is commonly done both in glass tubes and in tubes with non-wettable surfaces.This presentation concerns the development of a portable mechanical device, the Coagulation Timer, to perform this test. The end point is measured automatically by a photo-electric mechanism. Only a few minutes are required to draw blood and place samples in the machine, which may then be left unattended.Data are presented to show that results obtained using glass tubes in the Coagulation Timer correlate well with those of a technician using a modification of the Lee White method. Further data are presented establishing the normal range for the whole blood clotting time using polystyrene tubes in the Coagulation Timer.
The Treatment of Patients with Factor-V Deficiency
Authors: Rush B , Ellis H 
Published: June 2018

SummaryTwo patients with congenital factor-V deficiency and a third with a combined deficiency of factor V and factor VIII are described. Under cover of fresh frozen plasma, tooth extractions were performed on two of these patients and spontaneous bleeding arrested.It is concluded that the achievement of a blood level of factor V of 20 per cent once daily is sufficient to assure adequate haemostasis. A low recovery of factor V activity in the plasma following infusion was found. However, in spite of this, adequate blood levels were easily attained due to the excellent preservation of factor V activity in the stored fresh frozen plasma.
Platelet Function in Congenital Afibrinogenemia
Authors: Gugler E , Lüscher E. F 
Published: June 2018

SummaryPlatelet functions have been studied in relation to hemostasis in two patients with congenital afibrinogenemia.Neither in the plasma nor in the aqueous platelet extracts of these patients was fibrinogen detectable by immunoelectrophoresis or with the aid of the Ouchterlony technique. ADP-induced platelet aggregation, adhesion to connective tissue particles, viscous metamorphosis under the influence of thrombin, clot retraction activity of the platelets, as well as their factor 3 activity were all found normal. Abnormal was the behaviour of the patient’s platelets on glass surfaces : they were unable to adhere to glass and the typical spreading on such surfaces was equally missing. This defect was normalized in vitro by the addition of small amounts of fibrinogen and correspondingly the patients platelets showed normal adhesiveness after fibrinogen transfusions. Normal platelets, suspended in afibrinogénémie plasma lost their adhesiveness toward glass surfaces.After transfusion of Cohn fraction I the prolonged bleeding time of the patients was normal and the clinical improvement presisted for a period of about 3 weeks, this inspite of the fact, that no fibrinogen was detectable by the usual methods 10 days after the transfusion.The significance of these results as well as their implications for the role of fibrinogen in hemostasis are discussed.
Observations on Factor VIII (Antihaemophilic A Factor) Stability in Rabbit and Rat Plasma Estimation of Factor VIII in Rat Blood by a New Method
Authors: Nilsson D , Waaler B. A 
Published: June 2018

Summary1. Factor VIII activity of rat and rabbit plasma can be measured with a modification of the thromboplastin generation test.2. Using this method it can be shown that factor VIII activity is unstable on storage and on repeated freezings and thawings in oxalated plasma from the two animal species. The factor VIII activity is especially unstable in oxalated rat plasma, from which it disappears almost completely by four or more repeated freezings and thawings.3. A rat oxalated plasma, which had been frozen and thawed ten times, could be used as a factor VIII-free reagent in a simple one-stage test system for measurements of this factor in rat or rabbit plasma.4. The method developed may be used with rat tail capillary blood as test material, making repeated observations on rats possible. The use of the method is discussed.