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  • Author or Editor: Jiunn-Guang Lo x
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Abstract  

The reactions of recoil38Cl atoms produced through the37Cl(n,)38Cl process in the CF3Cl–C2H4 gas phase are described in this work. The CF3Cl is a chlorine source as well as moderator. Scavengers, such as O2 and H2S, were added to the system to discriminate the reactions induced by energetic and/or thermal chlorine atoms. The radioactive38Cl-labeled products were separated using gas-chromatogarphic technique followed by an external proportional counter for quantitative determination of the product yeids. The mechanisms of the chemical reactions are predicted to account for the formation of these organic compounds.

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Abstract  

Reaction of recoil tritium atoms with ethyl alcohol in the gas phase has been studied in the presence of moderator and scavenger. The total amount of tritium produced from3He (n, p) T reaction under given irradiation conditions is determined by adding methane as a monitor for each set of sample. The HT, CH3T, C2H5T and C2H4TOH yields were due to the decrease of hot reaction with increasing moderator pressure. On the other hand, the C2H3T yield, due to the unimolecular reaction of excited CH4TOH* or C2H5T* moleculas, decreased with increasing pressure. All tritiated compounds were analyzed by radio gas chromatography.

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Abstract  

The pertechnetate ion to forms a yellow complex with cysteine ( max=420 nm) under anaerobic conditions. The kinetic order with respect to pertechnetate and cysteine has been determined by HPSEC and titration method. The oxidation state of the yellow Tc-cysteine complex was determined by potentiometric titration.

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Abstract  

Lipiodol has excellent retainable ability in hepatoma cells. This agent can be labeled with radioisotope (131I) and mixed with tissue adhesive (Histoacryl), and then alttached on the lesion of liver by intrahepatic arterial administration. In this study, we attempt to obtain the optimal ratio of Lipiodol to Histoacryl and evaluate the consolidation of blood in vitro and toxicity and biodistribution in vivo. The ratio of131I Lipiodol/Histoacryl mixture (L/H), concentration of heparin and flow rate of blood are varied by simulating the installation of bloodstream to test the time of consolidation. In addition, the optimal ratios of the L/H mixtures are assessed in vitro in heparinized human blood. According to those results, Lipiodol and Histoacryl mixed with 1∶1 or 2∶1 ratio have an ideal time of 13 to 15 seconds in vitro; in addition, 1.2∶1 ratio is an optimal ratio in the biodistribution study. Interestingly, heparin and acetic acid does not alter the consolidation time, in addition, no variation occurs when varying the flow rate of blood. The consolidation of L/H mixture with blood is incubated in the 37°C, normal saline bath for 24 hours. No dissociation of free131I is found. The optimal mixture is also injected into the hepatic artery of the Sprague-Dawley rats carrying for 24 hours. No dissociation of free131I is found. The optimal mixture is also injected into the hepatic artery of the Sprague-Dawley rats carrying hepatocellular carcinoma (NIS1 cell line). Radioactive consolidate is well confined in the tumor without evidence of leakage of the mixture to the lung or distribution of free131I in the thyroid. In conclusion, this mixture has the merits of both irradiation and embolization of the tumor. The131I Lipiodol/Histoacryl mixture (1.2∶1) is a promising alternative for intrahepatic arterial administration to treat hepatic tumors. Histoacryl can confine the131I and, also, embolize the tumor vessels.

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Abstract  

The labeling behavior of cysteine with99TcO 4 ion and/or99mTcO 4 ion at different cysteine concentrations reductant and pH values has been studied by chromatography, and the labeling yield was calculated. Three major Tc-complexes, yellow, reddish brown and green can be separated by gel filtration chromatography (GFC). Thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and ion-exchange chromatography (IC) were used to separate the complexes collected from GFC. The TLC, HPLC data show the pertechnetate accompanied with a yellow complex; the green and purple complex contain more than two complexes. Electrophoresis and IC data show that the complexes carry a negative charge. The conductivity, UV-VIS, flow beta-detector with HPLC and autoradiography are also applied to analyze complex formation.

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Abstract  

Tolonium chloride is a common reagent in the diagnosis of oral premalignant and malignant lesions. This study establishes the optimal preparation of radioiodinated tolonium chloride (RTC) and evaluate its radiochemical and biological characteristics. Instant thin layer chromatography (ITLC), ion exchange chromatography (IC), paper electrophoresis, and the effect of pH on labeling efficiency revealed the chemical characterization of RTC. Biodistribution, blood clearance, urinary excretion, toxic effect, and Lugol’s solution effect on the thyroid uptake of RTC revealed RTCs biological characteristics. The optimal labeling condition was pH = 2.96 after 15 h stirring, the labeling efficiency was 60%. After purification by IC, the radiochemical purity of RTC was 94%, and the shelf life of RTC was at least 90 days. In the biodistribution study, the liver was major target organs, approximated 6.11% of injected dose accumulate in per gram of tissue (6.11% ID/g) at 10 min after injection. The tissue-to-blood radioactivity ratio significant (p < 0.05) increased with reaction time. In liver, the tissue-to-blood radioactivity ratio was 2.2 ± 0.51 at 10 min after injection, and increased to 22.4 ± 4.52 at 120 min after injection. The blood clearance study showed a significant decrease in blood radioactivity. The radioactivity in the blood was about 2.76% of the injected dose per milliliter blood at 10 min post-injection, but decreased to 0.12% at 120 min post-injection. Lugol’s solution does not affect the thyroid uptake of RTC. Almost all the administered RTC recovered at 60 h after injection, with 79% recovered in feces and 17% recovered in urine. This study shows that RTC is non-toxic, and may be suitable as a liver imaging agent.

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