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

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

[en] Graves' disease is the most common cause of hyperthyroidism. Clinical features include thyroid enlargement, eye signs, tachycardia, heat intolerance, emotional lability, weight loss, and hyperkinesis. Three modes of therapy are available. The preferences of the patient and physician are usually prime considerations in devising the therapeutic plan. Radioactive iodine is the most frequently used and safest method of treatment for adults. Antithyroid drugs are preferred for children and pregnant women. Surgery is usually reserved for patients in whom the other forms of treatment are not acceptable. Considerable patient education during the decision-making process enhances the success of the therapeutic plan

[en] Radioiodine-labeled pharmaceuticals have been used extensively in diagnostic nuclear medicine. We have developed a rapid and mild method for incorporating radioiodine into functionally substituted molecules. The new process involves the reaction of the radioiodide ion with organoboranes in the presence of gentle oxidizing reagents. The radioiodide is utilized nearly quantitatively in a matter of seconds. The radiochemical yields are excellent, and parallel those obtained when iodine monochloride is reacted with organoboranes