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  • Author or Editor: Y. Shafiq x
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Abstract  

(6-3H)-Thymidine, (5-3H)-methyl-thymidine, and (5-3H)-thymidine were synthesized by the use of tritiated water. The specific activities of the products were 3.3, 3.4 and 3.0 mCi/mM, respectively. These tritiated thymidines are important tracers to study human lymphocytes and human chromosomes.

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Abstract  

A99Mo/99mTc generator, system was made with a performed titanium molybdate gel. The irradiation was carried out at a medium neutron flux of 1.5×1013 n cm–2·s–1. The irradiated matrix was loaded on top of a column composed of hydrous zirconium oxide alumina. The elution efficiency and the amount of total technetium per mCi99mTc in the generator eluents have been determined. Molybdenum breakthrough has also been determined and compared with literature values. The influence of the particle size, water content, neutron flux and molybdenum content on the total99mTc-activity has been investigated.

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Abstract  

Mouse serum was fractionated and isolated to pure mose sub-class immunoglobulin (IgG1, IgG2a, IgG2b) on protein A-sepharose 4B Microprecipition method was used to ascertain the purity of mouse IgG-sub class, labeling and coupling efficiecy with90Y and99mTc were determined by paper chromatography as a simple and rapid tool for analysis. The parameters investigated included the ratios of DTPA: IgG2a and DTPA: Sn, pH and protein concentrations. The optimal coupling efficiency for90Y was achieved at DTPA to IgG2a molar ratio of 11 pH 8,4 and specific activity of 2 Ci/g for IgG2a coupled with about 1 goup of DTPa per 1 molecule of IgG2a, while the optimal coupling efficiency for99mTc was achieved at a DTPA to IgG2a molar rato of 50:1, pH4 and specific activity of 1 Ci/g for IgG2a. Affinity column chromatography with sephadex G50 and protein A sepharose 4B were used to determine the immunoreactive and non-immuoreactive mouse antibody IgG2a coupled with DTPA at different molar ratios and99mTc90Y atoms incorporated into each antibody. Anti-IgG2a affinity column and anti-human transferrin affinity column were used to determine in vitro stability of99mTc DPTa-IgG2a. Freeze-dried kit of IgG2a-Sn-DTPA to be labeled with99mTc was prepared under sterile condition Each vial contained 1.0 mg IgG2a-Sn-DTPA in about 100 l.

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Abstract  

Kits were developed for labeling sulphur microcolloids with99mTc. The microcolloids were prepared to get the desired particle size. The stannous chloride was treated with sulphide ions released from thioacetamide in the presence of carboxymethyl cellulose and the pH of the reaction was adjusted to 3.0. The contents of single reaction vial were reacted with99mTc, the radiochemical yield was higher than 95%. Sulphur-microcolloid kits were stable and the stability was followed for 6 hours. The freeze-dried kits were followed more than three months after production and were found stable. Bone marrow uptake in rabbits was determined to be about 36%. The preparation of99mTc-sulphur microcolloid is performed in single step process and axellent node scintigraphy was obtained using experimental animal.

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Abstract  

Correlation between the in vivo distribution and the chemical formulation of99mTc-PYP complex has been studied. We chose mice to evaluate in vivo biodistribution and gel chromatography column scanning technique for radiochemical analysis. The influence of the pH, Sn(II), pyrophosphate concentration and molar ratios of Sn: PYP on the labelling of pyp with99mTc has been investigated in vitro and in vivo. The reaction between99mTc and Sn-PYP was complete within a few minutes. The stability studies were evaluated against dilution. Induced myocardial infarction was evaluated in rats. The clinical evaluation showed excellent definition of sternum and ribs with little blood background activity with normal subjects. Discrete localization of abnormally high activity was shown in the site of recent infarction of the left ventricular myocardium.

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Abstract  

The distribution of four different commercially available A, B, C, D kits (99mTc-sulfur colloid) for hepatoimaging was compared in mice by organ radioassay and in rabbits for blood clearance. The distribution of kits A and C (single step kits) was assessed in the human by blood clearance, external liver, spleen measurement, and scintillation camera imaging. Kit A reaches a high concentration in liver within 15–20 minutes with relatively high surrounding tissue background, and superior spleen scintiphotos. However, when kit C was used, a high activity concentration in the liver was reached within 10–15 minutes with low tissue background and faint visualization of the radiotracer in the spleen. Blood clearance of the four99mTc-sulfur colloids was determined in rabbits. The data obtained indicated that the four hepatoagents exhibit rapid blood clearance but the initial decrease of blood activity curve of kit D was relatively faster than the other three hepatic agents. The biodistribution is similar for the four99mTc-S-colloids but the blood retained higher activity residue using kit A compared with others. The formation of99mTc-sulfur colloid using kits B, D (multistep kits) involves many steps after the addition of99mTcO 4 to the reagent. These procedures are time consuming, required facilities at the medical institutions and give rise to the radiation exposure. While single step kits A and C have the same diagnostic value, the use of kit C allows a reduction of absorbed radiation, which may be useful in the liver exploration in children.

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Abstract  

Labelling of DTPA bicyclic anhydride coupled antibodies were investigated by determining the effect of DTPA: antibodies, DTPA: Sn molar ratios, pH, dimer and polymer formation of antibodies coupled with DTPA, using three different radionuclides, [111In,90Y and99mTc]. Analyses were performed with by Whatman No. 1 paper strips. Under optimal conditions we have achieved specific activities of111In or90Y labelled antibodies of about 37 kBq/1 g for IgG coupled with about 2 DTPA groups per molecule and protein concentration of 15 mg/ml.

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