The present studies examine the effect of starvation together with cold or hot exposure on thyroid hormone levels in rats. At 23°C starved for 5 days, serum thyroid hormone levels decreased significantly compared with fed rats, averaging 3.6±0.5μg/dl of thyroxine (T4), 47±11 ng/dl of triiodothyronine (T3), 1.4±0.3 ng/dl of free T4 and 39.6±5.1 pg/ml of reverse T3, respectively. At 15°C rats starved for 5 days, serum free T4level significantly more increased than that of 23°C starved rats, while serum T4level and T3did not increase significantly. At 30°C rats whether concomitant starvation or not, serum thyroid hormone levels of both group markedly more decreased than control rats. These experiment provide additional evidence that thyroid gland and the peripheral metabolism of thyroid hormone respond to variety situations such as cold or hot exposure together with starvation or not.
Intraduodenally administered14C-urokinase (14C-UK) was located in Macaca Irus by autoradiography. Sagittal sections, approximately 40pm thick, of a frozen monkey were applied against X-ray films. Autoradiograms thus obtained indicated that a part of intraduodenally administered14C-UK was incorporated into the systemic blood circulation by transintestinal mucosal membrane.
With the purpose to use for therapeutic drug monitoring (TDM), blood concentrations of tobramycin (TOB) in each patient were measured by radioimmunoassay (RIA) . A RIA kit of TOB (Clinical assay-Japan Travenol) was evaluated for precision and recovery, in that partial improvement of the method was made, in order to measure low level of TOB. The RIA was compared with high-performance-liquid-chromatography (HPLC), bioassay (BA) and 2 kinds of enzyme immunoassay (EIA) (EMIT and SLFIA) . The RIA of TOB revealed high precision (1.8-2.4% in C.V.) and high reproducibility (5.0-6.9% in C.V.) . It was found that this RIA kit can be used for measuring low level of serum TOB concentrations by a modification of the method. The total range of measurable blood level is from 0.1 to 16.0μg/ml. The nearly one to one correspondence was observed between RIA and other 4 methods, when 154 samples obtained from 18 cases were measured. A representative case of TDM for TOB was demonstrated, in which predicted concentrations agreed fairly well with actual measured values at steady state. It was concluded that the RIA kit is useful for clinical application of TDM for the adequate dosage regimen of TOB. Modification of the method for rapid assay of a small number of samples will increase the clinical usefulness.
It is well known that very large storage tanks for radioactive liquids are necessary for the disposal of liquid radioactive waste. In vitro tests in radioimmunoassay in nuclear medicine are rapidly increasing for clinical examination causing marked increase in the volume of liquid radioactive waste. Thus we have developed a system for decontaminating radioactivity from liquid waste. In the first step, the liquid waste is boiled by a sterilizer and, in the second step, this sterilised liquid is filtered by a cylindrical filter (Toyo filter No.84) . After filtration, the liquid waste is passed into a beaded charcoal column and an ion exchange resin (Amberlite IRA 402) column. After these treatments, the radioactivity level of liquid waste is lowered to less than 1 % of the original radioactivity. We are now in the planning stages of building an apparatus for practical use.