Lithium benzoate was irradiated at various thermal neutron fluence in reactors. A plot of the specific activity of benzoic acid derived from irradiated lithium benzoate vs, the thermal neutron fluence measured with59Co activation detectors gave a linear relationship on a logarithmic graph paper in the range of thermal neutron fluence from 1.3×1014to 2.2×1017 ncm-2. This finding indicates that lithium benzoate is available as an activation detector for recoil tritiation by the6Li (n, α) 3H reaction.
Since deuterium gas is different from hydrogen gas in thermal conductivity, the deuterium quantity of deuterated hydrogen HD can be determined with a thermal conductivity detector. HD is obtained by the isotopic exchange reaction between heavy water and hydrogen gas by means of a platinum catalyst. H2 (G) +HDO (L) _??_CatalystHD (G) +H2O (L) We developed a high activity platinum catalyst. A simple method for determination of heavy water was achieved by combined use of gas chromatography and platinum catalyst. After the isotopic reaction between sample heavy water HDO and hydrogen, the generated water is removed by molecular sieve. The deuterium quantity of the generated HD is measured by injecting it into a thermal conductivity detector of gas chromatograph under flowing carrier hydrogen gas, as the chromatogram. The value of coefficient of variation in the analytical results is less than 3%, and 0-100% heavy water is able to be determined simply and rapidly with good reproducibility.
This paper describes the biological radiation effects of carbon-14 and tritium labeled 5-fluorouraeils (5-FU) which were given intraperitoneally at resonable dose (14C: 1.85 MBq/kg (0.05 μCi/kg), 3H: 3.7 MBq/kg (0.1 μCi/kg) ) and its forty times dose once a day for 3 days in mice. The results indicated that the change of body weight, urine and feces volume and its radioactivity, and organ weight and its residual radioactivity except pancreas were not observed any significant difference between three groups of both14C and3H, but white blood cell number markedly decreased proportionally with radioisotope dose of both14C and3H and also red blood cell number decreased by [6-3H] -5-FU 148 MBq/kg i.p. The results suggest that high level radioisotope dose of both14C and3H 5-FUs have no biological radiation effects on the studies of drug metabolism in vivo, however that in the case of hematogenie organ, the biological radiation effect is not disregarded.
A correlative study of autopsy findings and retrospective review of gallium scintigrams were performed in 106 older ages cases. Of these cases studied, 57% demonstrated positive gallium study in the present series. Histological correlation was undertaken in cases of lung cancer. Among them, squamous cell carcinoma showed the highest incidence of positive results (83%), whereas adenocarcinoma was the lowest (35%) . There is no apparent correlation between subtypes of histological classification of adenocarcinoma and abnormal accumulation of gallium. However, abnormal accumulation of the nuclide seems to be rather related with interstitial reactions, namely fibrotic changes, lymphocyte infiltration and vascularization.
A radiometric method for the determination of manganese, based on the exchange reaction between*Zn-EDTA and Mn in the presence of PAN has been developed. The Zn-PAN complex formed due to exchange, was proportional to Mn content. When the complex was extracted into chloroform from ammonia-ammonium chloride buffers, at pH 8.5, 4-50μg Mn could be determined. Effect of diverse ions on the exchange has also been studied.
Determination of iron (II) by radiochemical displacement of65Zn from Zn-PAN has been studied. pH 5.5 in borate buffers was suitable for the quantitative displacement. Interference due to diverse metal ions has also been reported.
Self irradiation of the CaSO4: Tm-TLD (National UD-200S), a commercial thermoluminescense dosimeter (TLD) of high sensitivity, was measured by keeping 10 samples taken from each of 10 batches of the TLD in a lead brick enclosure located underground for 20 days. In one batch was observed a very high self-irradiation of 186±26 fA/kg (2.6±0.36μR/h), which was about 3 times as large as for the other 9 batches. The source of this high self irradiation was investigated by the analysis of variance and identified to be the cap of the holder of thermoluminescent detectors which incorporates the Sn-Pb alloy filter for the energy compensation.
Usefulness of three kinds of TSH kits by immunoradiometric assay (IRMA) was evaluated. They were able to measure low levels (less than 0.1 μIU/ml) in serum thyroid stimulating hormone (TSH) with incubation of short time (4 hours) . In particular, RIABEAD II kit had a highly specific affinity for TSH and the normal range (±2 S.D.) using it showed from 0.20 to 3.50 μIU/ml in 150 normal subjects. In patients with hyperthyroidism and in patients with hypothyroidism, the values of TSH were lower and higher than those of normal subjects, respectively. Another kits showed similar results. These results indicate that these TSH-IRMA kits are useful to evaluate serum TSH levels exactly.