No abstract available

No abstract available

[en] Two coumarins, 4-bromomethyl-6,7-dimethoxy-2-oxo-2H-benzopyran (1) and 4-bromomethyl-7-methoxy-2-oxo-2H-benzopyran (3), were radio-iodinated using trifluoroacetyl hypoiodite. The dimethoxy derivative 1 gave only a single regioisomer 3-[¹²⁵I]iodo-4-bromo-methyl-6, 7-dimethoxy-2-oxo-2H-benzopyran (2). The average yield for no-carrier-added preparations of 2 was 30%. ^125/127I-2 and ¹²⁷I-2 were produced in over 50% yield. In no-carrier-added syntheses 7-methoxy-coumarin 3 gave 3-[¹²⁵I]iodo-4-bromomethyl-7-methoxy-2-oxo-2H-benzopyran (5) as the major product (30%) accompanied by a small amount (3-7%) of the 6-[¹²⁵I]iodo-analog 4. When an equimolar amount of iodide was used (i.e. carrier-added syntheses) 4 and 5 were produced in over 20% yield each. Under these conditions the 8-iodo-regioisomer was not formed from either 1 or 3 possibly as the result of steric effects. Sonication greatly accelerated rates of radioiodination reducing the time required to achieve quantitative substitution of ¹²⁷I from about 4 h to 20 min. (author)

[en] Peptide labelling with radioactive isotopes is always a compromise between peptide chemistry, labelling chemistry, and biological receptor tolerance. Therefore new ways for isotope introduction are always useful. The present contribution describes the introduction of iodine isotopes onto synthetic polypeptides by means of the Gattermann/ Sandmeyer reactions. Peptides containing the nitrophenylalanyl residue are reduced to the corresponding aminophenylalanyl, diazolized to the diazonium phenylalanyl peptide and converted to the iodophenylalanyl peptide in the presence of copper. Two examples are presented: angiotensin II and enkephalin. In both cases, the iodophenylalanyl residue is well accepted by the biological target. (author). 13 refs.; 4 figs

[en] Short communication

[en] The resources to conduct dosimetry and optimize treatment for radioiodine therapy of Grave's disease patients are not always readily available in resource-deficient regions, with limited Nuclear Medicine facilities and serving a large population. The calculation of activity required to achieve cure remains debatable and dependent on multiple factors. A standardized fixed activity had been a necessity in our setting to be able to benefit patients, without requiring the excessive arduous preparation that may be required. The aim of this study is to investigate the efficacy of a fixed radioiodine activity in treatment of Grave's disease. Patients treated with a fixed dose of 10mCi between the periods of 2014 to 2015 were evaluated. A 2 year post initial treatment review was done to assess treatment response. We included 104 patients, 87 females and 17 males, (mean age 41.1±13.4 years). Of the 83 patients with follow up data, there was a 90.4% successful treatment response (36% euthyroid; 64% hypothyroid) with 85.3% responding after only 1 administration, 13.3% required a single repeat and 1.3% a second repeat. There was a total of 8 non-responders. No statistically significant relationship to response to treatment was demonstrable for fT4 (p= 0.468) and TSH (p = 0.137) levels at the time of treatment. There was no correlation of response with gender (p=0.87). A fixed low empiric radioiodine activity of 10mCi may be optimal for curing hyperthyroidism due to Grave's disease and justification for higher activity should be specified. This method of therapy may be beneficial where resources are limited and where patient numbers are too high. (author)

No abstract available

No abstract available

[en] Two patients have recently been seen with recurrent epidermoid carcinoma in the nasopharynx. Both have achieved local control and are disease-free after a brachytherapy procedure. The technique for interstitial nasopharyngeal brachytherapy is described

[en] Short communication