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[en] To deveolp 99mTc instant labelling kits of dimercaptosuccinic acid (DMSA), glucoheptonic acid (GH), and tin colloid, molar ratios of the host compound to the stannous chloride, amount of the stannous chloride and pH were, respectively, controlled. The labelling yields and radiochemical purities were checked by means of a paper chromatography. Animal studies and clinical applications were also carried out. The results indicated that DMSA/SnCl2 2H2O 3/1(mole/mole), SnCl2 2H2O 410ug/ml/vial, pH 2.5, Ca GH/SnCl2 2H2O 53/1(mole/mole), SnCl2 2H2O 350 ug/ml/vial, pH 6.5, NaF 100ug/vial, SnCl2 2H2O 150 ug/ml/vial, pH. 5.6 etc, were optimal conditions for the preparation of DMSA-, GH-, and tin colloid-kits, respectively. (Author)
[en] Various TSH RIA kit components were prepared. Conditions for 125I labelling of h-TSH were optimized by diminishing the amount of chloramine-T, extending reaction time and lowering reaction temperature. Yield, specific activity, and immunological activity could be maintained moderately under such mild reaction conditions. The mixture of polyethyleneglycol (PEG) and second antibody worked effectively as a B/F separation agent. Even though the mixture was made with more diluted PEG and second antibody than those of using the sole component separately, the time required for the B/F separation was shorter in case of using the mixture. The sequential saturation technique was efficient than those of applying ordinary equilibrium saturation technique in assay sensitivity and assay precision points of view.
[en] Various experiments for the quality control of Tc-99m labelled radiopharmaceuticals such as Tc-99m-phytate, Tc-99m-MDP, Tc-99m-Tin Colloid, Tc-99m-DISIDA, Tc-99m-DTPA,Tc-99m-DMSA, Tc-99m-Gulcoheptonate, TC-99m-Pyrophosphate, Tc-99m-HSA, and Tc-99m-HAM were carried out. Labelling yield and radiochemical purity of each of the instant labelling kit of KAERI made were determined by means of radiochromatography. Biodistribution in mice and whole body or specific organ imagings of rabbits were also carried out and discussed the relationship between the data of biodistributions and radiochemical purities. Labelling yeilds were above 98% for almost all of the labelling kits. The radio-pharmaceuticals were accumulated at each target organ with moderate specifities. In case of radiochemical purity of above 98%, the biodistribution and gamma imagings were also better. The kits of MDP and DISIDA were stable at least for four moths while the other kits at least eight months. (Author)
[en] To develop 99mTc instant labelling kit of d,1-HMPAO and 131I labelled IMP for the regional cerebral blood flow scintigraphic use, d,1-HMPAO and IMP were synthesized. The former was prepared from 2,3-butadione monoxim and 2,2-dimethyl-1,3-propanediamine in the presence of cation exchange resin, and then selective reduction of imine bond with sodium borohydride followed by fractional crystallization of diastereometric mixture of HMPAO. The latter was prepared by condensation of p-iodophenylpropanone with isopropylamine, and then reduction of double bond with sodium borohydride. For the preparation of 99mTc labelled HSA, experiments on incorporation of bifunctional chelating agent of DTPA to HSA, establishment of optimal conditions of 99mTc labelling, determination of labelling yield and radiochemical purity, and examination of stability were carried out. (Author)
[en] To develop 131I-labelled m-iodobenzylguanidine (1311-MIBG), various experiments such as synthesis of MIBG, establishment of labelling conditions, determination of radiochemical purity, and examination of stability were carried out. 1) m-Iodobenzylguanidine (MIBG) sulfate was synthesized with a total yield of 62.4% by the condensation of m-iodobenzylamine hydrochloride with cyanamide via MIBG bicarbonate. Its physical properties, IR, 1H-NMR, and elemental analysis data were nearly identical to those of literature. 2) Freeze-dried or vacuum-dried kit vials were prepared from the mixture so as to contain MIBG (2 mg), ascorbic acid (10 mg), copper (II) sulfate (0.14 mg), and tin (II) sulfate (0.5 mg) per vial. Copper (I) catalyzed radioiodination of MIBG was carried out using kit vials and 0.01 M H2SO4 as solvent at 100 .deg. C for 30 min under nitrogen atmosphere (optimal conditions). Labelling yield was 98% and radiochemical purity was 99.5%, respectively. 3) Solid-phase radioiodination of MIBG was carried out at 155 .deg. C for 30 min using the prepared vials to contain MIBG (2 mg) and ammonium sulfate (10 mg). Duplicate reactions under the same conditions showed labelling yield of 95% and radiochemical purity of 99.5%. 4)131I-MIBG prepared either by catalytic or by solid-phase exchange method showed radiochemical purity of 99% even after 3 days storing at room temperature.
[en] For the development of 99mTc Labelled 3-Iodo-2 , 4, 6-trimethyl-iminodiacetic acid (99mTc IOTIDA), various experiments such as synthesis of IOTIDA, establishment of labelling conditions, determination of radiochemical purity, examination of stability, and organ distribution of rat were carried out. 1) IOTIDA was synthesized with a total yield of 42% from the stating material of trimethylaniline via chloraacetylation, iodination, and condensation with iminodiacetic acid (IDA). 2) Freeze-dried instant labelling kits were prepared from aqueous solution (pH 5.8-6.0) so as to contain 40 mg IDA compound and 0.4 mg SnCl2 per vial. Labelling of the contents of kit vials with Na99mTcO4 exhibited formation of two kinds of complex (II) with time. Labelling yield and radiochemical purity were above 99.5% based on the two complexes overall. 3) 99mTc IOTIDA maintained high radiochemical purity of above 99% until 6 hours after preparation at room temperature. Instant labelling kits stored at 4 .deg. C for 6 month period also exhibited high labelling yield of above 99%. 4) Results obtained from animal experiments showed that most of the 99mTc IOTIDA was rapidly excreted through hepatobiliary track into the intestines but with negligible renal excretion.
[en] In order to develop 99mtechnetium-labelled human albumin microsphere (HAM) for lung scintigraphy, various experiments such as preparation and fractionation of HAM, establishment of optimal labelling conditions, determination of radiochemical purity, stability test and biodistribution of 99mTc-HAM were carried out. HAM was prepared from the suspension of I ml aqueous human serum albumin (25%) in 130 ml of olive oil at 130 - 135 .deg. C with vigorous stirring. The resulting HAM was fractionated with microsieve to get the desired particle size (15 - 50 μ) and autoclaved for sterilization. The HAM particles were treated with stannous chloride and the pH of the suspension was adjusted to 3.0 - 3.5 with phosphate buffer. After freeze-drying the contents of single reaction vial containing 5 mg of HAM and 0.2 mg of SnCl2 it was reacted with Na99mTcO4. The labelling yield was higher than 99.5% and the stability of 99mTc-HAM was high enough to maintain 99.1% of radiochemical purity up to 24 hours. Lung and liver uptake in mice was found to be 94% and 0.9%, respectively. Excellent rabbit and human lung scans were also obtained.
[en] For an effective solid-phase labelling of protein with 125I, studies on the immobilization of lactoperoxidase (LPO) on the inner wall of polystyrene tubes were carried out. Labelling of bovine serum albumin (BSA) and insulin was also practiced using the LPO immobilized tubes. The immobilized enzyme of about 2.5 μ g/tube was sufficient for small scale labelling since the results of radio-paper chromatography of the labelling mixture of insulin indicated that the yields were sufficiently high (80%) even in the reactions conducted at room temperature for 60 sec. The results of the Sephadex column chromatography indicated that the labelled products were not contaminated with LPO-125I, and the radiochemical purity of the products was more than 90%. In considering the general trend that the 125I labelled protein obtained by using LPO maintains its intactness better than those obtained by using chloramine-T, together with the tendency of yield enhancing with increase of reactants-concentration, the LPO immobilized tube method is estimated to be one of the simple methods of labelling. The product might be applicable without further purification.
[en] Using stannous chloride, optimum conditions for 99mTc labelling of some scanning agents such as phytic acid (PA), dimercaptosuccinic acid (DMSA), and calcium diethylenetriaminep- entacetate (Ca-DPTA) were established. Methods of separation and identification of the labelled compounds were practiced by a paper- or thin layer- chromatography. Biodynamic studies of the compounds were also carried out. The results indicate that the molar ratios of the chelating agent and stannous chloride varies only with the concentrations of the chelating agents, and thus the amounts of the stannous chloride per labelling tube were neatly constant(500-600 μg) regardless the variation of the molar ratios. It suggests that the given experimental conditions require about 500 μg of stannous chloride regardless of the chelating agents. Under alkaline pH, the labelling yields were drastically decreased due to the probable formation of colloidal tin compounds. Biodynamic clara showed characteristic patterns with each compound indicating that they are all suitable far the relevant scanning applications.
[en] Biodistribution studies has been carried out to elucidate the cause of poor bone imagings often encountered in using methylenediphosphonate (MDP)-99mTc and establish effective conditions in using the popular bone imaging agent. After 150 minutes from the I.V. injection of MDF-99mTc to mice, the radioactivities accumulated at bone (B), liver (L), and stomach (S) were counted. The radiochemical purity (RCP), the volume, the radioactivity concentration and the amount of radioactivity of MDF-99mTc were controlled. Data were expressed either in %cpm/g-organ or %cpm/organ. The organ distribution ratios (B/L and B/S) were correlated with the RCP, the volume of injection, the radioactivity concentration etc. Results indicated that the RCP plays a major role in biodistributions. High radioactivity concentration and injection of a small amount is recommended. Negligible effect was observed with the amount of radioactivity. It has been confirmed that the up-to-date methods of RCP determinations cannot sensitively detect the sharply affecting trace impurities. A particular biodistribution pattern of crossed B/L and B/S lines was observed in case of using MDF-99mTc of low RCP. In such a case, rather a higher dosage would be effective for improving the contrast between bone and liver.