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  • Author or Editor: A. El-Bayoumy x
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Abstract  

An adopted method for the preparation of high radiochemical purity 125I-atenolol was investigated. Direct radioiodination of atenolol was carried out using N-bromosuccinamide or hydrogen peroxide as an oxidizing agent. The reaction proceeds well within 30 min at room temperature (25 ± 1 °C) and afforded a radiochemical yield up to 97% as pure as 125I-atenolol. Different chromatographic techniques (electrophoresis, TLC and HPLC) were used to determine the radiochemical yield and purity of the labeled product. Biodistribution studies were carried out in normal Albino Swiss mice and the results indicate that 125I-atenolol can be used safely as myocardial imaging agent.

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Abstract  

Extraction of Eu3+ from 0.1M aqueous perchlorate medium by thenoyltrifluoroacetone (HTTA) and by mixtures of HTTA and tributylphosphate (TBP), HTTA and triphenylphosphine oxide (TPPO), HTTA and trioctylphosphine oxide (TOPO) and HTTA and triphenylarsine oxide (TPAsO) has been studied at various temperatures allowing for the elucidation of the mechanism of extraction in each case and a comparison between the various bases.

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Abstract  

Polyclonal antibody production in mammals is generally associated with multiple injections of antigens and adjuvant and repeated blood sampling procedures. In the production of second polyclonal antibodies, a number of critical steps can be identified that may influence the outcome of the animal experiment (immunological results and the pain and suffering of the animals). The goal of this work was to evaluate critical steps in the production of these antibodies, and to optimize production protocols that will ultimately result in effective antibody responses. This work was achieved through immunization of two healthy sheep by purified Alpha feto protein (AFP) antigen. Also, the present study involved the preparation of AFP standards from human cord blood. Furthermore, preparation of a radiolabeled AFP tracer of a high specific activity using 125I isotope by chloramine T method was undertaken. Moreover, this study provides that there was no observable difference between the Scottish Antibody Production Unit (SAPU) and Sigma SAM IgG and the two second antibodies obtained from the local sheep sera.

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Abstract  

Celecoxib was labelled effectively with 99mTc. The labeling yield was found to be influenced by the amount of celecoxib, the amount of stannous chloride dihydrate, the reaction time, the temperature and the pH of the reaction mixture. The importance of stannous chloride dihydrate arises from its function as a reducing agent for pertechnetate to form complex celecoxib. The suitable amount required to produce high labeling yield of 99mTc-celecoxib was 500 μg SnCl2·2H2O. The pH of the reaction medium was found to play a significant role in this labeling process. The labeling reaction was performed at a neutral medium (pH 7). The labeling reaction proceeds well at room temperature (25 ± 1 °C) and the complex decomposes by heat. The labeled celecoxib (99mTc-celecoxib) showed a good localization in inflamed foci and a good imaging must be taken 4 h post injection.

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Abstract  

A study on the labeling of hippuran with no-carrier-added131I assisted by Cu(I) and excess of ascorbic acid is described. The role of ascorbic acid is to prevent the oxidation of Cu(I) to Cu(II) which activates the hydrolysis of o-iodohippuric acid to o-iodobenzoic acid. The use of Cu(I) allows an almost quantitative (97–99%) labeling yield to be obtained within 10–15 minutes at 100°C. The reaction is assumed to take place via the formation of an organocopper complex favoring the exchange reaction between radioiodine and inactive iodine in the hippuran molecule. The activation energy of the reaction was calculated to beE=12.2 kcal/mol.

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Abstract  

Human AFP was used as an antigen for the development of monoclonal antibodies by the hybridoma technique. Balb/c mice were immunized with highly purified AFP. The preparation of I125-AFP was carried out by lactoperoxidase oxidation method, preparation of AFP standards was carried out from cord sera. The antibody titer of the serum was tested by RIA-AFP system. The spleen of the immunized Balb/c was fused with Sp20 mouse myeloma cells. The cells from the positive hybridomas were cloned twice using limiting dilution method. Eleven stable clones were thus established for secreting monoclonal antibodies to AFP. Cells in this growth phase were chosen for freezing.

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