Spatial Substitutes of the Lead Vector Triangle

Kowarzyk, H; Kowarzyk, Zofia; Jagielski, J

doi:10.1038/2061365a0

Cited by 5 publications

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“…Die Wirkung der Hemmstoffe laBt sich auch bei der durch APC bewirkten Umwandlung von gereinigtem Prothrombin in Gegenwart von Calciumionen, Acceleratorglobulinen und Lipiden untersuchen. Wie das in Abb 2. dargestellte Versuchsbeispiel mit Ixodin zeigt, wird die Thrombinbildung bei Zusatz einer ausreichenden Hemmstoffmenge zum Aktivierungsansatz vijllig verhindert.…”

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Versuche zur Hemmung der Autoprothrombin C-Wirkung

Markwardt¹,

Hoffmann²,

Landmann³

1964

Thromb Haemost

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Versuche zur Hemmung der Autoprothrombin C-Wirkung

Markwardt¹,

Hoffmann²,

Landmann³

1964

Thromb Haemost

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“…The Nelson-Brody effect could be con sidered if (a) the electrical resistance of the blood were the main factor affecting the phenomena, and (b) if in all homeotherms the dipole orienta tion were mostly radial. Previous work, however, demonstrated that the changes in QRS amplitude in poikilotherms and in homeotherms are not dependent upon the resistance of the filling solution (saline, glucose, or olive oil) [7,9], Furthermore, it was shown [5] that in the chicken heart, the magnitude of the surface potential is mostly dependent upon dipoles oriented tangentially as is the case in poikilotherms; yet, the chicken ECG shows a decrease in QRS amplitude during bleeding of the same type as homeotherms [I3j. These observations suggest that neither the resistance of the intraventricular mass nor the differences in the dipoles orienta tion can explain the differences in the QRS amplitude changes during bleeding.…”

Section: Discussionmentioning

confidence: 99%

Role of the Cardiac Conduction System in Determining the QRS Amplitude after Bleeding

Manoach¹,

Grosman²,

Varon³

et al. 1974

Cardiology

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The QRS complex in the ECG of poikilotherms is increased by bleeding. The opposite reaction is observed in homeotherms. In previous studies, the type of QRS response to hemorrhage and infusion was ascribed to a phylogenetic difference, namely the presence or absence of a specialized conduction system in the heart. In order to substantiate the role of the specialized conducting system, two mammalian preparations were designed using the same species (cat) under conditions allowing both specialized conduction and cell-to-cell conduction. Comparison of the changes observed during bleeding or transfusion in the R’ wave of cats with bundle branch block, and in the depolarization wave obtained by ventricular pacing (both of which mimic poikilotherm conduction), with the changes in the R wave in normal cats, clearly show the dependence of the changes in QRS amplitude on the type of conduction system in the heart.

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“…The third line of investigation was based on the isolation and characterization of a specific protein of the "prothrombin complex" designated autoprothrombin C, which was first described by Kowarzyk and Marciniak in 1961 [53]. Autoprothrombin C is now accepted as being equivalent to Factor Xa.…”

Section: Historical Backgroundmentioning

confidence: 99%

The Chemistry and Enzymology of Bovine Factor X

Henriksen¹,

Jackson²

2008

Semin Thromb Hemost

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In the currently proposed schemes for blood coagulation [14,57,94], Factor X lies at the point of convergence of two distinguishable routes by which clotting is initiated. These two routes have been labeled the intrinsic and extrinsic coagulation pathways. Factor X exists in the plasma in an enzymatically inactive or zymogen form which, during coagulation, is activated to yield the proteolytic enzyme Factor Xa. Activation of Factor X via the intrinsic pathway requires only plasma-contained clotting factors, while the extrinsic pathway requires the participation of tissue-derived substances as well as plasma factors. The only known physiologic substrate for Factor Xa is another zymogen, prothrombin, which is activated to yield the protease thrombin. In turn, thrombin acts upon fibrinogen-yielding fibrin, which polymerizes to form a fibrin clot. Since the activation of Factor X is the first reaction common to both the intrinsic and extrinsic coagulation pathways, this activation process must be viewed as a key event in initiating thrombin formation as well as subsequent fibrin clot formation. Likewise, control of this activation process, as well as the consequent action of Factor Xa, becomes critical to regulating the formation and subsequent action of thrombin.A vitamin requirement for normal blood coagulation was first shown from the work of Dam [12], who named this vitamin "vitamin K." It was subsequently demonstrated that vitamin K was necessary for the formation of four specific plasma proteins, blood coagulation factors VII [52,77], IX [64,71,84], and X [3,42,84] in addition to prothrombin [89]. Of these proteins, in addition to Factor X itself, one is the substrate for Factor Xa, and the other two are responsible for Factor X activation.In the present discussion, we shall consider the isolation and characterization of Factor X, the process by which it is activated to yield Factor Xa, and finally the properties of Factor Xa as a proteolytic enzyme. This is not intended as a comprehensive review of all work in the field, but rather a presentation of what we believe to be salient features of Factor X chemistry and enzymology as well as recent developments in this field. The authors recognize that the development or our understanding of the chemistry and function of Factor X is the product of the contributions of many workers, some of whom may not be explicitly credited. We apologize for such omissions and would welcome their being called to our attention.

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Spatial Substitutes of the Lead Vector Triangle

Cited by 5 publications

References 0 publications

Versuche zur Hemmung der Autoprothrombin C-Wirkung

Versuche zur Hemmung der Autoprothrombin C-Wirkung

Role of the Cardiac Conduction System in Determining the QRS Amplitude after Bleeding

The Chemistry and Enzymology of Bovine Factor X

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