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Die vorliegende Arbeit beschaftigt sich mit Analysen des Blutes im Rahmen groserer Untersuchungsreihen zur Implantation eines kunstlichen Herzens beim Kalb.

The course of an infection apparently caused by a filterable virus of the blood of the shore crab. Carcinus maenas , has been experimentally studied in this host both at Roscoff, France. where it was originally found, and at Woods Hole, Mass., where the local species was also found susceptible. Although a portion of the infected animals die with the symptoms of inadequate blood clotting, recovery of this function occurred promptly in about two-thirds of the animals. Half of the animals that recovered this function did so within 4 to 6 days. Recovery was not accompanied by disappearance of the virus from the whole blood. In tests done as late as 40 days after recovery, virus was still present. Autointerference was demonstrated after acute infection. It was found in the serum of animals with manifest disease on all days tested and in whole blood of animals taken more than 2 days after the clotting defect appeared. It was not demonstrable within the whole blood within the first 2 days of disease. The role of this in the recovery phenomenon is discussed.

Three different lots of 50 mg. capsules of dicumarol produced markedly different effects on the blood clotting mechanism in dogs. Upon microscopic examination of the content of the capsules, a relationship between the particle size of dicumarol and the dissolution rate, inhibition of normal prothrombin activity and plasma concentration was found.A general linear relationship was observed between the logarithm of drug concentration in plasma and the pharmacological effect of dicumarol produced by the three capsules. Also, as the area under the plasma concentration-time curve increased, so did the area under the percent inhibition of normal prothrombin activity-time curve produced by the three dicumarol capsules.

SummaryThe enzyme kinetics of competitive inhibition under conditions prevailing in clotting tests are developed and a method is given to measure relative amounts of a competitive inhibitor by means of the t — D plot.

Hemorrhagic diatheses in childhood constitute a variety of disorders with a common tendency to bleed. They may be manifested in the form of petechial spots, purpuric extravasations or ordinary loss of blood from free surfaces. These clinical expressions of a disorder of the blood represent active hemorrhagic disease in all grades of severity. But there is a comparable group of disturbances of the blood in which a tendency to bleed or clot representing potential hemorrhagic disease may be precipitated by a sudden change in the vascular system. These latent aspects of hemorrhagic disease have thus far been neglected. Hemorrhagic disease, latent or active, results from an alteration in either the vascular system or its blood content. An understanding of the mechanism must be based first on knowledge of the normal formative tissue. The reticulo-endothelium is the common hematopoietic tissue which is capable of giving rise to different varieties of blood

Summary. Investigations have been carried out on the chemical groupings in factor VIII with a view to discovering the biochemical mechanisms involved, and the chemical groups responsible, for its particular blood clotting properties. Bovine factor VIII has been treated with iodine, hydrogen peroxide, iodoacetamide and the sodium salt of p-Chloromercuribenzoic acid. Each of these reagents is known to react with thiol groups. Each inactivates factor VIII and, in the case of the mer- cury compound, factor-VIII activity can be regenerated using cysteine. Preliminary results indicate that similar effects are obtained using human factor VIII. It is concluded that factor VIII contains thiol groups situated at or near to the active sites of clotting. Possible applications of these new findings are also discussed. In particular, it may provide more insight into the storage stability of factor-VIII concentrates.

SummaryRepresentatives of modern thrombolytic agents have been shown to possess certain in vitro clot accelerating activities, which a variety of experiments indicate to be due to a ‘Hageman-like’ effect. This activity is surface dependent and remarkably resistant to long keeping (in active plasmin) and to acid heating, unlike ‘surface factor’ (‘activation product’). The effect is quite powerful under certain test conditions, but it remains to be seen whether it is of any significance during the use of thrombolytic agents therapeutically.

SummaryIt is demonstrated that clotting time in a thrombotest experiment bears a linear relationship to the inverse of factor X concentration under conditions in which the ratio of factor X to the factors II and VII is equal to or smaller than the ratio in normal plasma.A similar relationship occurs with other thromboplastins as long as factor V and fibrinogen are present in excess, i. e. when the dilutions are made with BaSO4 absorbed plasma.Contact activation causes deviation from the observed straight-line relationship.

There are, as is known, several methods for preparing serum to be used for therapeutic and diagnostic purposes, but the clotting process and the defibrination followed by centrifugation have widely been employed with noticeable efficiency in practical work. While by the former method clear and sterile serum is obtainable, simply allowing the blood to clot, the latter gives higher percentages in the gain of serum. It often occurs, however, by employing the latter method that the material is accidentally contaminated during the process of centrifugation and the serum obtained becomes quite unfit for use. In order to prevent the accidental contamination and to obtain a large possible amount of sterile seerum, several kinds of apparatus have atreacly been designed. As it will be of great interest to know which is the best method, which is the best apparatus and in what condition the serum gain is largest, I have made some experiments, employing the known methods and apparatuses, to determine, as a first step, the relation between the yield of serum and the amount of bleeding, slight starvation, atmospheric pressure, temperature, size and shape of glass jar, etc. The apparatuses used in my experiments are:1) The apparatus used in the Pasteur Institute, Paris.2) The bucket for blood clotting designed by the Laboratory of the Indian Civil Veterinary Department.3) Latapie's apparatus.The results obtained are as follows:1) The yield of serum depends upon the individuality of animals and the total sum of the serum which is obtained from the usual clot at 2-day-intervals during 9 days amounts to 41-64% of the whole blood drawn.2) The percentage of serum from the first bleeding (4000c.c.) was lower by 6.5% than that from the second which, being same in the quantity of blood, took place 2 days later.No influence of an atmospheric pressure and slight starvation upon the yield of serum has been observed.4) The adequate temperature for separation of serum is about 20°C.5) The amount of serum obtained is proportional to the height of glass jar.6) The compressive method employed in the Veterinary Laboratory at Buitenzorg (Java) is most applicable in horse and swine blood. According to the experiments, this method requires no complicated apparatus, shortens the time necessary for collec-ting serum, gives serum 4-13% more than that obtained from the usual clot, and the serum is guite free from hemoglobin. As for the bucket of Indian Civil Veterinary Laboratory, it seems to be more favourable to use it for the preparation of serum from cattle blood, though the serum is often found in an impure state, slightly mixed with red blood corpuscles.

IT IS now common knowledge that chicks on certain specialized diets devoid of vitamin K show spontaneous internal and subcutaneous hemorrhages. Such birds are known to have a greatly reduced plasma prothrombin concentration and hence demonstrate a prolonged blood clotting time. Once a vessel is ruptured it is to be expected that the escaping blood would fail to clot rapidly and a hemorrhagic appearance result. However, no satisfactory explanation is yet available as to why the small vessels in the vitamin K-deficient birds spontaneously break down. Dam and Schonheyder (1934) suggested that the hemorrhages were initiated by traumatic stimuli. Almquist (1937) conceded such a possibility but also observed that many sources of bleeding were on protected surfaces of the body or located internally, indicating the hemorrhages to be completely spontaneous. In this laboratory we have had the experience of observing hundreds of vitamin K-deficient chicks. Practically all of these birds . . .

SummaryThe effect of chronic intoxication of rabbits with beta-aminopropionitrile on blood clotting and fibrinolysis was studied.The increase of clotting time of whole blood and recalcified plasma accompanied with the decrease of factor IX, XI and XIII level were observed. On the other hand the significant increase of fibrinogen content and soluble complexes of fibrin monomers level was found.A deep inhibition of fibrinolytic activity of plasma was stated. The decrease of thromboplastic and fibrinolytic activity of saline extracts of some internal organs was also observed. The mechanism of above described changes and their significance in pathology are discussed.

There have been conflicting reports concerning the effect of the ingestion of fat on the coagulation of blood. A shortening of the whole blood clotting time (WBCT) or of the plasma clotting (recalcification) time was found by several investigators to follow the intake of fat, either in the form of cream or of a more complex meal of fat.'?. 1°. w, i6,23, 27 • At least 3 groups of investigators failed to confirm these findings in that they did not recognize any significant changes in whole blood clotting as a result of the ingestion of fat.'' Another discrepancy exists even among reports which affirm the phenomenon of fat-induced shortening of the blood clotting time. Waldron and his associates' found it to occur consistently within 1 hr. after the meal, even though very little fat was given (60 ml. of 20 per cent cream, i.e., 12 Gm. of fat). Other investigators, however, observed maximal acceleration of whole blood clotting to occur 2 to 6 hr. after the meal of fat,'' ' , 6 ' 2 3 usually coinciding with the height of the lactescence of plasma.

SummaryThe roles played by the blood clotting system and by fibrinolysis in the haemostatic balance are discussed. The significance of the tissue thromboplastin and the tissue activator of plasminogen for local haemostasis is emphasized, and their relation to anticoagulant therapy considered. Problems specific for coronary thrombosis, cerebral thrombosis and cerebral haemorrhage have been mentioned.

1. Es wird eine neue Methode zur adaquaten Untersuchung der Blutgerinnungsvorgange an unverandertem Vollblut beschrieben, welche erstmalig die fortlaufende Bestimmung der Fibrinelastizitat zur Grundlage hat. Sie erfast damit bei sehr kleiner Fehlerbreite quantitativ die direkte biologische Funktion der Gerinnung. Gleichzeitig mit der Fibrinelastizitat wird fortlaufend und quantitativ die Fibrinviscositat, die Retraktion und die Fibrinolyse aufgezeichnet, wobei sich die kritischen Zeitpunkte eindeutig darstellen.

Die Gerinnungsaktivitaten von Extrakten aus 10 Tage alten Erythrocyten unterscheiden sich nicht signifikant von denen aus frischen Erythrocyten. Durch mehrfache Extraktion mit Ather und Chloroform konnen nahezu alle thromboplastischen Substanzen der Erythrocyten extrahiert werden; die nach Extraktion verbleibenden Substanzen verlangern die Gerinnungszeiten von recalcifiziertem Citratplasma. Nach Zugabe der thromboplastischen Substanzen zu plattchenreichem Normalplasma bilden sich Zeichen eines Thromboplastinuberschusses aus, die durch einen fruhzeitigen Plattchenzerfall erklart wurden; dabei wird der Thromboplastinuberschus durch die mit Fettlosungsmitteln extrahierten Fraktionen deutlicher.

Accountants were selectively chosen as a self-controlled group for studying effects of cyclic occupational stress upon serum cholesterol and blood clotting time, since their routine work schedule is interrupted by urgent tax deadlines, associated with severe occupational stress. Forty male accountants (age 28 to 56) were bled biweekly for serum cholesterol and monthly for blood clotting time from January to June 1957. Complete records also were kept of weight, exercise, diet, relative work load, and any exposure to unusual avocational stress. When studied individually, each subject's highest serum cholesterol consistently occurred during severe occupational or other stress, and his lowest at times of minimal stress. The results could not be ascribed to any changes of weight, exercise, or diet. Marked acceleration of blood clotting time consistently occurred at the time of maximum occupational stress, in contrast to normal blood clotting during periods of respite. The possible implications of these results are discussed in relation to the problem of clinical coronary artery disease.

In recent years, indications have appeared in the literature that the observed postoperative bleeding in gastric patients depends mainly on biological changes in the blood the presence of thrombopenia in such patients, decreased blood clotting and leukopenia. We set out to test this opinion on our clinical material.

SummaryA basic biomathematical analysis of quantitative clotting test data becomes highly significant in the light of a complex logic which indicates a possible accord with certain postulated biophysical principles. Rectilinear plots are obtainable with one or other of two methods of analyzing the clotting-time data for an experimental system in which prothrombin is converted into thrombin by thrombokinase in the presence of specified cofactors.Determinants of enzymic activity fit the postulate of Michaelis-Menten kinetics and the Lineweaver-Burk double-reciprocal rectilinear plot. This holds when the ∼ substrate variable is (a) thrombokinase (as precursor of the true prothrombin-convertor enzyme), (b) specific cation (Ca++, Sr++, or Ba++), and (c) factor V (AcG). The validated assays are particularly meaningful in the case of factor V, and suggest a new system of unit age (AcGact)- Tentative Km values are given for these “substrate” functions.Determinants of effective thrombin (activated prothrombin) quasi-activity are studied by rectilinear log-log plots of endpoint clotting-times against the factor variable, when this is (a) prothrombin, (b) prothromboplastic phospholipid (cephalin), but (c) factor V (AcG) only to a limited extent. The discussion explains how these findings accord with certain colloidal principles that modify a basic enzyme formula based on “the inverse law.”Evidence of complexing of both substrate and enzyme with certain factors is provided, especially by exploring effects of successive suboptimal additions. The following mechanisms could explain the facts: (a) prothrombin + phospholipid form a colloidal (micellar) substrate complex ; (b) the true activating enzyme is thrombokinase after specific activation by cation (Ca++, normally) ; (c) factor V plays a dual role (in (a) and (b)), thus acting after the manner of an amboceptor. These key reactions should be added to the current “cascade” concept of blood clotting.

Summary A case of giant splenic hemangioma associated with thrombocytopenia and fibrinogen deficiency is described. The case presented clinically with severe bleeding and splenomegaly. Treatment with prednisone and transfusions of fresh blood and fibrinogen, was unsuccessful in controlling the hemorrhage. Following splenectomy, the patient improved considerably, the bleeding tendency disappeared and the blood findings became normal. The relationship between giant heman-giomata, either visceral or cutaneous, and the disturbed mechanisms of blood clotting is discussed.

In eight patients suffering from severe hemorrhagic disease it was possible to demonstrate the presence of circulating inhibitors, not heparin-like in nature. Anti-PTC was identified in two PTC deficients, anti-AHF in 5 hemophilics and both, primarily anti-AHF, in one idiopathic case. Possible etiologic factors inducing the appearance of such inhibitors included repeated transfusions of whole blood and plasma in all and a previous pregnancy in the idiopathic case. Two patients showed increases of gamma-globulin and presence of inhibitor in 25-33 per cent ammonium sulfate plasma fractions. Cortisone therapy was ineffective in two cases.

Three cases of extradural haematoma during ventricular drainage are reported and the relevant literature has been reviewed. Aetiology, diagnosis, and management are discussed. Defective blood clotting is mentioned as a possible precipitating factor.

SummaryIn its dependence upon prothromboplastic phosphatide and calcium ions, in the conversion of prothrombin to thrombin, Autoprothrombin C is a thromboplastic enzyme. The only other demonstrated accessory factor is V, and any needs for VII, X, XI, or XII are ruled out by the present experiments, as were VIII or IX formerly. The lipid requirement may be satisfied by either phosphatidylserine (PS) or phosphatidylethanolamine (PE), purified from human blood platelets. Comparisons are made with Russell’s viper venom (“stypven”), and with trypsin. The trypsin potentiation of factors VII and X is prevented by pancreatic inhibitor (PI). However, when PI is added after this maximal potentiation, it is no longer inhibitory. The present status of knowledge concerning enzymes in relation to blood coagulation is discussed.

SummaryThe interaction of cephalin and a phosphoinositide fraction extracted from beef brain was investigated. Variance analysis performed on the experimental data evidence a highly significant interaction between the 2 moieties as could be observed graphically by the non-parallelism of the regression lines.

Under certain restricted conditions purified thrombin can be added to purified prothrombin and the latter transforms to a derivative called autoprothrombin II. Except in 25% sodium citrate solution, it has not been converted to thrombin. It functions as a cofactor with purified platelet factor 3 in the conversion of prothrombin to thrombin. Serum from healthy persons and in hemophilia A contains autoprothrombin II activity that can be adsorbed on BaCO3. Autoprothrombin II, prepared in the laboratory, can be added to the two types of adsorbed serum and the autoprothrombin II activity is restored to the serum. Serum from PTA patient, and a patient receiving dicumarol was found to contain very little autoprothrombin II activity. By adding an appropriate quantity of autoprothrombin II, prepared in the laboratory, the autoprothrombin II activity of the PTC serum was not completely restored whereas it was with the other two serum samples.

SummaryPIVKA, the circulating anticoagulant protein found in vitamin K deficiency can, on kinetical grounds, be recognized as an analogue of factor X. The existence of analogues of other vitamin K-dependent clotting factors cannot be ruled out, but need not be assumed to explain the experimental results.

Several investigators have reported the occurrence of a syndrome in chicks which is similar to scurvy in appearance.1, 2, 3 Since several different diets were used in those studies employing different protein sources, it seemed useful to compare the effects produced by various proteins when fed with the same basal ration in order to observe if other proteins allowed the same symptoms to occur as did fish meal, as reported by Holst.The syndrome has been well described independently by Holst, McFarlane, et al., by Dam, and by Schonheyder.4 In using a ration similar to the one employed by Holst we were able to produce this syndrome which is characterized by (1) the production of hemorrhages without respect to location, (2) an anemia, and (3) a prolonged blood clotting time.Feeding experiments. Two groups of experiments were carried on. The diets used and results were as follows :Diet I—Control. Of 100 parts, corn 55, wheat 20; skim milk 20, NaCl 0.5, cod liver oil (Patch) 1, Ca3 (PO4)4 1, CaCO3 1, dried yeas...

An extensive literature is available on the role of lipids on blood clotting in vitro, but attempts to investigate the influence of lipids upon haemostasis itself, that is the arrest of bleeding, have been few. The only papers found in literature were those by Hirschfelder (1915), Hanzlik (1918a, b) and Hanzlik and Weidenthal (1919), where it was shown that crude cephalin when applied to the wound has some effect on the control of skin bleeding. Through the use of dog hind-leg preparation, adapted for studies on haemostasis in vivo, Cruz and Oliveira (1958) have provided experimental evidence to support the view that coagulation is not necessary for the arrest of bleeding in skin cuts, showing that normal bleeding times were obtained during perfusion with a noncoagulable blood sample (citrated arterial blood). In such preparations only arterial blood stops bleeding, whereas venous blood has no effect (Cruz, Oliveira and Magalhaes, 1958). We have used the inability of venous blood to arrest bleeding to demonstrate the haemostatic properties of various substances (Cruz, Oliveira and Magalhaes, 1959; Cruz, Magalhaes and Oliveira, 19600), which, when added to venous blood, converted it into haemostatic blood. It has been shown that crude cephalin was the active component of several organ extracts able to convert the non-haemostatic venous blood into haemostatic blood (Cruz et al, 1959). As a first attempt to identify the active substance of crude cephalin, Folch's fractionation method (Folch, 1942) was used, and the haemostatic capacity of fractions I, HI and V tested. The results, showing that most of the activity of crude cephalin is to be found in fraction V (Fy), are presented in this paper.

Blood clotting induced by non-purified norethynodrel is no longer observed in adult female rats when purified norethynodrel (99.7% pure) is used. Analysis of the times of bleeding and of coagulation of these rats treated with purified and non-purified norethynodrel clearly demonstrate that the purification of progestin eliminates the thromboembolic side effects. It is debated whether or not the concentration of estrogens can fully explain these side effects associated with the use of oral contraceptives. Furthermore, degradation products and/or contaminants during synthesis of this progestin would be, in large part, responsible for this blood clotting side effect in the female rat.

This paper reports a study of total thrombocyte counts, prothrombin index, clotting-times, and qualitative and quantitative determinations of the megakaryocytes in dogs with experimentally produced Hepatitis contagiosa canis. The megakaryocytes were studied in rib-marrow sections. A marked decrease was noted in the total number of thrombocytes down to less than 20,000 platelets per mm3 within 4–7 days of the inoculation. The prothrombin index changed very little. The haemorrhagic tendency in Hepatitis contagiosa canis is considered to be due to the thrombocytopenia in combination with vascular damage. A decrease in the number of megakaryocytes and qualitative changes in these cells were demonstrated. A prolongation of the clotting-time was established and its causes are discussed.