Nonylphenoxypolyethoxyethanol-toluene scintillator (NT-scintillator) has been found to possess excellent characteristics for counting tritium or carbon-14. Counting characteristics of the NT-scintillator for aqueous samples were examined in detail. By using 1N NaOH, 2N HCl and the NT-scintillator, various samples were incorporated in large quantities as stable homogeneous solutions for extended periods and counted at a constant efficiency. The present method was also shown to be applicable for the determination of radioactivities of tritium and carbon-14 doubly labeled compounds with the least troubles.
For liquid scintillation counting, the digestion techniques of biological materials by commercially available solubilizers, which belong to quarternary ammonium hydroxide, such as Hyamine X10, NCS, Soluene 100 and Digestin were studied. Six kinds of liquid scintillators: PPO+POPOP or butyl PBD in toluene, Davidson's DAM 611, Butler's cocktail, INSTA GEL and Triton X100 in toluene were examined against the solubilizers without biological sample for the colouring and the chemiluminescence and after the experiment, three liquid scintillators, butyl PBD in toluene and both of ether systems, were omitted from the next tests for the sake of their strong colouring. Comparing with the solubility of biological material; wet and dry muscular tissue of chicken, liver, kidney, spleen, plasma and blood of rat, the velocity of solubilization vse the amount of sample was measured. The maximum dissolved weight of sample to 1ml of each solubilizer is 200 mg in wet case and 100 mg in dry case, respectively. The chemiluminescence due to the mutual action between the scintillator and the solubilized biological sample in strong amine base was observed and its phenomenon decayed by neutralization with extremely small quantities of glacial acetic acid for toluene scintillator or 0.5 N hydrochloric acid for emulsion scintillator. The decolouring treatment for blood and spleen samples by 30% hydrogen peroxide was also described. It is concluded that the solubilizers dissolved in toluene (Soluene and NCS) are superior to those in methanol (Hyamine and Digestin), on the viewpoint of their digestion abilities and tritium counting efficiencies.
Triiodothyronine (T-3) concentration in sera from normal subjects and patients with various thyroid disorders was determined using radioimmunoassay kits. Value of normal subjects showed 135.8±24.9 ng/dl and there was no difference between male and female subjects. T-3 concentration in sera of hyperthyroid patients was 549.6±203.9 ng/dl and that in hypothyroid was 20 ng/dl. T-3 concentration in sera of patients who had received131I therapy or antithyroid drugs administration for thyrotoxicosis showed normal value. Sera from hypothyroid patients who were under treatment with thyroid hormone and maintained normal metabolic rate also showed normal T-3 level. Result of T-3 concentration determination, T-3 test and T-4 test showed correlation of some degree.
We have tested the TSH radioimmunoassay kit (Daiichi Radioisotope Labs., Ltd.) for its basic and clinical determinations. The results of serum TSH in various clinical states and TRH tests were also reported. The sensitivity, reproducibility and recovery of the assay were satisfactory. In normal subjects, serum TSH showed 5.6μU/ml in average, hyperthyroid subjects showed low, and primary hypothyroid subjects showed high levels. With TRH tests, hyperthyroidism showed low or non response, whereas primary hypothyroidism showed exaggerated and delayed response. In secondary hypothyroidism, increase or no increase of serum TSH were observed. In observed values, there was a good correlation with the values obtained by the use of NIH kits.
The authors carried out a scintigraphy and a linear scan in 23 patients with congenital atresia of the bile ducts using131I-BSP, and compared to discriminate from those in infantile hepatitis. The liver scintigrams and the linear scans were taken immediately, 3 hours, and 24 hours after the intravenous injection of131I-BSP. In congenital atresia of the bile ducts, the scintigram revealed no picture of131I-BSP excreted in the intestinal tract even after 24 hours, but many pictures excreted in the kidney in general. In linear scanning study, the scanning curves were similar in every test time, there being many backgrounds. In infantile hepatitis, on the other hand, the scintigram showed the increasing excretion in the intestinal tract with time and the reducing background. Also in the linear scan, the curves showing the excretion in the intestinal tract were obtained.