99/00764 Re-evaluation of the biological half-time of caesium in Japanese male adults

1999 ◽  
Vol 40 (1) ◽  
pp. 76
1983 ◽  
Vol 2 (1) ◽  
pp. 101-120 ◽  
Author(s):  
N.D. Priest ◽  
G. Howells ◽  
D. Green ◽  
J.W. Haines

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.


1985 ◽  
Vol 8 (3) ◽  
pp. 203-210 ◽  
Author(s):  
Isamu Tanaka ◽  
Shigeko Ishimatsu ◽  
Koji Matsuno ◽  
Yasushi Kodama ◽  
Kenzaburo Tsuchiya

1962 ◽  
Vol 17 (3) ◽  
pp. 429-432 ◽  
Author(s):  
F. R. Gibb ◽  
P. E. Morrow

Six dogs each received two 60-min exposures, 6 months apart, to an aerosol of iron 59 oxide, having an average count median diameter of 0.09 μ and a geometric standard deviation of 1.8. The concentration of iron 59 in the inspired air ranged between 0.004–0.017 μc/liter. Lung measurements were made immediately after each exposure and up to 30 days postexposure. This procedure was followed in both initial and repeat exposures of each dog. A probe-type scintillation detector fitted with a focusing collimator was used to limit the measurements to specific respiratory tract positions on each dog. The biological half-time for alveolar clearance in the 12 studies ranged from 44 to 82 days with an average value of 62 days (sd 8.8 days). This consistency suggests the probability of a normal clearance rate and the possibility of its use as a functional test. Submitted on July 11, 1961


1983 ◽  
Vol 21 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Seiva YAMAGUCHI ◽  
Kenichi SANO ◽  
Nobuhiro SHIMOJO

1989 ◽  
Vol 56 (4) ◽  
pp. 473-484 ◽  
Author(s):  
H. Mailhot ◽  
R. H. Peters ◽  
R. J. Cornett

1965 ◽  
Vol 13 (01) ◽  
pp. 001-007 ◽  
Author(s):  
J. J Veltkamp ◽  
E. A Loeliger ◽  
H. C Hemker

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.


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