scholarly journals The Biological Half-Time of Hageman Factor

1965 ◽  
Vol 13 (01) ◽  
pp. 001-007 ◽  
Author(s):  
J. J Veltkamp ◽  
E. A Loeliger ◽  
H. C Hemker
Keyword(s):  
Polycythaemia Vera ◽  
Factor Xii ◽  
Half Time ◽  
Hageman Factor ◽  
A Value ◽  
Biological Half Time

SummaryThe biological half-time of factor XII was assessed (a) after transfusion of freshly-drawn, normal intact ACD-plasma into a patient having Hageman trait and suffering from polycythaemia vera, and (b) with blocked synthesis in a patient suffering from acute liver dystrophy due to phosphoric intoxication. The results obtained suggest that the biological half-time under normal conditions has a value between 50 and 70 hrs.

Generation Of Factor XII-Dependent Plasminogen Activator Activity In Human Plasma Measured With A Fluorogenic Substrate

1981 ◽  
Author(s):  
G Dooijewaard ◽  
C Kluft
Keyword(s):  
Human Plasma ◽  
Plasminogen Activator ◽  
Minor Role ◽  
Factor Xii ◽  
Dextran Sulphate ◽  
Fluorogenic Substrate ◽  
A Value ◽  
Substrate Activation ◽  
Factor Xiia ◽  
A Minor

A rapid fluorometric assay for measurement of amidolytic activity in human plasma was developed, using the plasminogen activator sensitive synthetic substrate t-BOC-L-valyl--glycyl-L-arginine-β-naphthylamide. The plasma is diluted in a reaction cuvet containing 0.050 M Tris HC1 buffer (pH 8.0) and 150 μM substrate. Activation of plasminogen proactivator(s) is initiated at 37°C by the addition of 10 μg dextran sulphate (MW 500,000)/ml. The concentration of β-naphthyl- amide released is recorded fluorometrically as a function of time. The slope of this curve at any time t is proportional to the concentration of activator. Thus, in a single assay, the entire time-dependent profile of activation and subsequent inhibition is monitored; this provides 1. a value for an optimum plasminogen activator content in the plasma, and 2. the time it takes to reach the optimum. The plot of optimum activator content against μl of plasma added is linear for dilutions more than 100-fold, suggesting that under these conditions the optimum content approaches the content of proactivator(s) originally present.The activator content measured predominantly consists of contributions of a factor XII-dependent process since 1. without dextran sulphate or with plasmas deficient in factor XII or prekallikrein no activity could be generated, and 2. plots of optimum activator content against dextran sulphate concentration show sigmoidal-shaped saturation curves as found previously for the kallikrein generation in human plasma. Contributions of factor XIIa and kallikrein only partly account for the content measured and studies with plasmas deficient in factor XI point to a minor role for this factor, if any. Further identification of the activator (s) involved is in progress.

Activation of factor XII (Hageman Factor): Enhancing effect of a potentiator

1977 ◽  
Vol 10 (2) ◽  
pp. 309-313 ◽  
Author(s):  
John Y.C. Chan ◽  
Clement E. Burrowes ◽  
Henry Z. Movat
Keyword(s):  
Factor Xii ◽  
Enhancing Effect ◽  
Hageman Factor

scholarly journals Factor XII (Hageman Factor) Deficiency: a rare harbinger of life threatening complications

2019 ◽  
Vol 33 ◽  
Author(s):  
Liaqat Ali Chaudhry ◽  
Wael Yasin Mohamed El-Sadek ◽  
Ghazala Aslam Chaudhry ◽  
Feddha Eid Al-Atawi
Keyword(s):  
Factor Xii ◽  
Hageman Factor ◽  
Factor Deficiency ◽  
Life Threatening

Pattern of Uptake of Americium-241 by the Rat Skeleton and its Subsequent Redistribution and Retention: Implications for Human Dosimetry and Toxicology

1983 ◽  
Vol 2 (1) ◽  
pp. 101-120 ◽  
Author(s):  
N.D. Priest ◽  
G. Howells ◽  
D. Green ◽  
J.W. Haines
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Cortical Bone ◽  
Female Rat ◽  
Half Time ◽  
Bone Surface ◽  
Similar Model ◽  
Phagocytic Cells ◽  
Biological Half Time

The distribution and retention of intravenously injected 241Am in the skeleton of the female rat has been investigated using autoradiographic and radiochemical techniques. The studies were designed to assess the dosimetric and toxicologic implications of an 241Am intake by man. They showed that in the rat approximately one third of the intravenously injected 241Am was deposited in the skeleton where it appeared to be retained with a long biological half-time. The studies also showed: 1241Am is initially deposited onto all types of bone surface including endosteal surfaces, periosteal surfaces and those of the vascular canals within cortical bone, but seems to be preferentially deposited onto those that are resorbing, 2 Bone accretion results in the burial of surface deposits of 241Am, 3 Bone resorption causes the removal of 241 Am from surfaces, 4 Resorbed 241Am is retained by phagocytic cells (probably macrophages) in the bone marrow, 5 The transfer of 241Am from the phagocytic cells in the marrow to adjacent bone surfaces seems to occur, (local recycling). 6 The possibility that some of the 241Am removed from the bone surfaces enters the blood and is redeposited in bone, (systemic recycling) cannot be dismissed These results show that 241Am deposition and redistribution in bone shares many characteristics with other 'bone surface-seeking radionuclides' typified by 239Pu. Consequently, it is suggested that a similar model to that used to calculate annual limits of intake for 239Pu in man would be suitable for the calculation of corresponding values for the 241Am isotopes.

Simultaneous deficiencies of early components of complement (C) and hageman factor (Factor XII)

1973 ◽  
Vol 51 (2) ◽  
pp. 101-101
Author(s):  
M GLOVSKY ◽  
C KASPER ◽  
A ALENTY ◽  
I GIGLI
Keyword(s):  
Factor Xii ◽  
Hageman Factor

scholarly journals Induction of expression of monocyte interleukin 1 by Hageman factor (factor XII).

1992 ◽  
Vol 89 (24) ◽  
pp. 11969-11972 ◽  
Author(s):  
Z. Toossi ◽  
J. R. Sedor ◽  
M. A. Mettler ◽  
B. Everson ◽  
T. Young ◽  
...  
Keyword(s):  
Interleukin 1 ◽  
Factor Xii ◽  
Hageman Factor
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