The geometrical efficiencies of a point and a disc source on the radiation detection by a detector with circular window were calculated by a polynomial expression. Those were calculated in the case of a source off the center line of the detector window, too. It was found that the geometrical efficiency Gpof a point source at a point P (x, z) off the center line, in the case of z≥5A, can be approximately expressed as: Gp/Go=1.0-1.54 (x/z) 3+0.89 (x/z) 3 Go=1/2 (1.0-D/z) : geometrical efficiency of a point source on the center line. The geometrical efficiency Gsof a disc source (radius R) on the center line, in the case of z≥5A, can be approximately expressed as: Gs/Go=1.0-0.84 (R/z) 2+ (R/z) 3
The recoveries of very low level210Po in airborne dusts, in an electrochemical displacement treatment, were determined. Two methods were used here, the one is a direct method by the use of natural210Po and the other is a tracer method. Both recoveries determined by two methods agreed well with each other. The recoveries of210Po in airborne dusts, at 10-12and 10-13Ci could be considered as being better than 90%. The values are similar to the ones at higher levels.
This study was undertaken to clarify the absorption and excretion of cadmium in the body. The excretion into the feces and urine, the absorption and excretion through the gastrointestinal tract, the distribution of109Cd were investigated in mice by means of the sample measurement and the whole body autoradiography. Orally administered109CdC12was poorly absorbed from the gastrointestinal tract into the body and the greater part of the109Cd was excreted into the feces. Intravenouslly injected109CdC12was excreted into the gastrointestinal tract through the gastrointestinal wall and the bile duct, and excreted into the feces. In either oral administration or intravenous injection, the109Cd was excreted into the urine a little. To compare the absorption and excretion in each gastrointestinal tract divided into 10 parts, 109Cd was relatively well absorbed in the lower part of small intestine, and excreted in the middle and lower part. The109Cd absorbed into the body was distributed to the liver, the kidney, the gastrointestinal wall, the pancreas, the salivary gland and the other tissues. It is concluded from the results obtained that the greater part of ingested cadmium (inorganic cadmium) is excreted into the feces and a little part of it is absorbed into the body, and a little part of the absorbed cadmium is excreted into the gastrointestinal tract and subsequently excreted into the feces.
This is a report on the basical and clinical study of Thyopac 4 method developed by RCC, which is a simple method of measuring thyroxine (T4) in the blood. The procedure of Thyopac 4 was easier than that of Res-O-Mat T4 and Tetrasorb T4 method, and automatic counter was available to this method. Stable values were obtained about 30 to 40 minutes of incubation time at about 23°C room temperature. Concerning variation of the measurement values σ was ±12.3%. Normal values ranged from 4.7 to 12.9 μg/dl. These values were compared with Res-O-Mat T4 values, thyroidal uptake of 131I and Thyopac 3 values measured at the same time. The correlation and the clinical value were as follows: Thyopac 4 value was well correlated with Res-O-Mat T4 value and Thyopac 4/Res-O-Mat T4=0.938±0.02 with the correlation rate of 89.3%. Thyopac 4 value was also well correlated with the 24-hour thyroidal uptake of131I with the correlation rate of 82.7%. In the correlation between Thyopac 4 value and Thyopac 3 value Katayama line was determined, of which upper line was θ=∠35°, and lower line was μ=∠11°18'. Various diseases were divided by these lines. When we assume Thyopac 4/Thyopac 3=Thyopac FTI value, the correlation between Thyopac 4 value and Thyopac FTI value was significant with the correlation rate of 94.0%, and the correlation between Thyopac FTI value and the 24-hour thyroidal uptake of131I was also significant with the correlation rate of 84.2%. As described above, the measurement of thyroxine in the blood by Thyopac 4 was very simple and valuable from both basical and clinical points of view.
The method for determining unsaturated iron binding capacity (UIBC) using resin strip was investigated. This method can be performed at room temperature, and the limits of incubation temperature and time are not so strict. In case the room temperature is too low, it can be compensated by prolonging the incubation time accordingly. The exact amount of serum being taken up, a fairly good reproducibility could be obtained. In the normal serum, majority of UIBC values were 150-250μg/dl, in many cases with hyperthyroidism, however, the UIBC values were higher, in many cases with malignant tumor the UIBC values were within the normal range.
A part of transferrin in serum is binding iron, and the rest of it is designated as unsaturated iron binding capacity (UIBC) . The UIBC is defined as the capacity for binding iron. The sum of UIBC and serum iron content is total iron binding capacity (TIBC) . In general, UIBC and serum iron content are in inverse proportion with each other, but the value of UIBC is also variable owing to the increase and decrease of transferrin. Although a lot of chemical methods have been applied to the determination of UIBC, it is troublesome to keep the experimental apparatus free of iron and it is not easy to prepare the standard solution of iron. Since a several years the authors have been em-ploying the method using59Fe for the determination of UIBC. A few of studies on this method were made, and the results are reported here. Results: The differences in the duplicated determination of UIBC were found to be 0.2-32.0 (14.2) μg/dl. Notable differences were observed in the case of hyperferremia. This indicates that much cautions should be taken for the determination of UIBC which is of low value. Under consideration of the effect of temperature on the reaction rate, the preferred incubation time was studied at 22°C and 37°C. At 22°C the reaction continued along with time, while at 37°C the reaction reached to plateau after 30 min, and thereafter the rate of reaction was almost constant. The effect of skill in measuring of the serum volume on the value of UIBC was little in the case of hyperferremia, however it was very notable in the case of normal and hypoferremia. The serum iron content and the value of UIBC which were determined at the same time correlated inversely to each other, although there were variations in each case. The normal values of UIBC were found to be 163-265 (211±37. 5) μg/dl in 21 men and 148-275 (215±32.8) μg/dl in 23 women, respectively.