Whole body counting

Am that has been deposited into specific organs or tissues, such as the lungs, liver, bones, or lymph nodes, can be detected and quantified using whole body counting techniques that appropriately... 

In assessing initial exposure, whole body counting techniques measure amounts of americium that have been deposited within organs or tissues and have not been excreted. In cases of accidental ingestion, some of the americium may have been excreted in the urine or through the feces, before exposure is assessed. In... 

Moore MR, Meredith PA, Watson WS, et al. 1980. The percutaneous absorption of lead-203 in humans from cosmetic preparations containing lead acetate, as assessed by whole-body counting and other techniques. Food Cosmet Toxicol 18 399-405. 

Transfer of technetium from seawater to animals has been studied by laboratory experiments using 95mTc, The advantages of 95mTc over "Tc are 95mTc emits y-rays, thus whole-body counting techniques can be used, and it has a sufficiently high specific activity because of its relatively short half life (61 d). 

Holma, B. (1967). Lung clearance of mono- and di-disperse aerosols determined by profile scanning and whole body counting A study on normal and S02 exposed rabbits. Acta Med. Scand. (Suppl.) 473 1-102. 

Hemphill FM, Hesselgren RD. 1971. Thorotrast quantities and whole body counts. Health Phys 21 85-89. 

When Thomson et al. (45) used an occulsive balloon to perfuse 54Mn into the duodenum and proximal jejunum of eight subjects, the rate of absorption averaged 27% over a 1 hour period. Mena et al. (46) had previously found a lower rate of absorption, 3%, for orally administered 54Mn by whole body counting for two weeks. However these authors felt that the measurements may have underestimated the amount actually absorbed since they could not account for the amount that had been absorbed and re-excreted. 

In healthy subjects the differences in the rate of zinc turnover are relatively small and a standard correction can be made. Otherwise repeated measurements of the rate of excretion can be used to extrapolate retention to absorption values at the time for intake of the meal. The retention measurements is done after two weeks to allow for long bowel transit time. The endogenous extretion of 65 Zn during this period is only about 10%. The radionuctide technique with 65 Zn and whole body counting are described in more detail in an other paper (15). 

Absorption of vitamin B12 can be investigated in several ways after oral delivery of radioactive vitamin B12 (e.g. containing Co) and subsequent measurement of radioactivity in faecal excretion, whole body counting or liver uptake, plasma radioactivity or the popular Schilling test. For the Schilling test, urinary excretion of radioactive vitamin B12 is measured 24 h following oral delivery, and impaired absorption may indicate intrinsic factor deficiency bacterial colonization of the small intestine (stagnant gut syndrome) or ileal disease. 

Absorption of stable zinc measured by this method compared to absorption of Zn measured by whole body counting are in agreement within the limits of error of the two methods (10) ... 

Normal Zn absorption was confirmed by whole-body counting of Zn. However the subjects retention of Zn was extremely shorty and turnover of Zn was faster when he was free-living than when he resided on the metabolic unit and consumed a carefully-controlled gluten-free diet (19). 

All of our absorption calculations, such as those presented above, have been based on the assumption that the first pulse of excretion represented unabsorbed isotope and subsequent excretion was post-absorptive These absorption values agree with metal absorption determined by other means, such as whole-body counting ... 

Whole body counting is performed on control groups from Helsinki, Liviisa, and Olkiluoto yearly. Lapps who are a risk group for radiocaesium incorporation are monitored in cooperation with the University of Helsinki. 

Miltenberger, R.P., Greenhouse, N.A. and Lessard, E.T., Whole body counting results from 1974 to 1979 for Bikini Island residents. Health Phys., 39 (1980) 395-507. 

Validation of the model. The Farris et al. model simulations were compared to an extensive set of data collected by the authors on the metabolism and distribution of an orally dosed bolus of radiolabeled methylmercury in male Sprague-Dawley rats. In a distribution study, tissue samples were collected on days 3, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, and 98 post-dosing. In a metabolism study with the same dosing regimen, whole body counts and 24-hour feces and urine samples were collected daily for 15 days post-dosing, and then twice weekly. 

A second animal bioassay method is the whole body counting method which has been described by Welch and Van Campen (5). In this method, food containing a radioactive tracer is given to the animals in a single dose and retention of the tracer in the whole animal over time is measured. Advantages include 1. the use of... 

To further evaluate the method, a series of meals were formulated and prepared to duplicate those of Cook and Monsen (7) (see Table I). These meals were chosen because they were used by Cook and Monsen in a study involving human subjects and, therefore, provided a means for comparison of in vitro and human in vivo methods. A rat in vivo method was also used in this study. The meals were homogenized, spiked with Fe, and administered to rats via stomach tube. Iron retention was measured using whole body counting. Figure 5 compares results obtained using these three methods. 

Tracer Adults (12) 17 (8-34) Healthy subjects without a pre-dosing fast. Absorption estimate based on whole body counting. LeRoy et al. 1966... 

Kozheurov VP. 1994. SICH-9.1 - A unique whole-body counting system for measuring Sr-90 via bremsstrahlung. The main results from a long-term investigation of the Techa River population. Sci Total Environ 142 37-48. 

If necessary whole-body counts are also taken. Whole-body counting is carried out with the subject being surrounded by numerous scintillation or solid state detectors in a heavily shielded room. The natural body content of is easily detected and is a control of the effici cy of this technique. 

The detector arrays scan the subject for normal whole-body counting, but the scanning detector geometry can... 

All subjects were measured in the whole-body counter in a supine position. The first count was a whole-body count with the detectors scanning over the subject. The counts were acquired in MCS mode simultaneously with the normal acquisition in an attempt to determine the location of (other than in the thyroid). The second count was a thyroid count where the subject remained supine, but also extended the neck to raise the thyroid gland above the clavicles. The results from the latter counts were used to determine the retention parameters. 

Edible tissues from terrestrial animals, aquatic animals, and fowl are measured for radionuclide content to estimate the radiation dose to humans from food consumption. Organs and tissue that concentrate radionuclides, such as radioiodine in thyroids or radiostrontium in bones and teeth, are analyzed as indicators of such radionuclides in the environment. Domestic animals are sampled at the normal time of slaughter. Wildlife samples can be obtained from hunters or by special collections. Because radionuclide concentrations in animal tissues vary widely, depending on species, feed or inhalation intake, location, and individual metabolism, multiple animals must be sampled to establish a normal range of radionuclide concentrations. Radionuclides that emit gamma rays can be measured in live animals by a technique similar to whole-body counting in humans. 

Individuals occupationally exposed to plutonium in the past are continually monitored in programs across the country. For example, whole body counting studies are currently conducted at Los Alamos National Laboratory in New Mexico. Animal studies conducted at the Lawrence Berkeley Laboratory, University of California, Berkeley, by P. Durbin are evaluating the behavior and movement of plutonium inhaled into the lungs. Models used to estimate body burden based on urinary excretion data and other biological measurements of plutonium (Leggett and Eckerman 1987) are under continual revision. 

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