Reoperation was performed in 110 of 185 patients with a differentiated thyroid carcinoma. In 25 patients (23 per cent) the indication for reintervention was a large thyroid remnant and in the other 85 (77 per cent) persistent or recurrent cancer was suspected. In 32 (29 per cent) of the 110 patients undergoing reoperation no evidence of cancer tissue was found. Tumour tissue in 33 patients (30 per cent) was resectable. Of 45 patients (41 per cent) with residual tumour after operation 24 showed only occult thyroid carcinoma with a raised serum thyroglobulin level. Eight of 21 patients with macroscopically persistent tumour died from the disease during a mean follow-up of 2.3 years. In 13 of 38 patients the investigated recurrent tumours were histologically less differentiated than the primary lesions, stressing the importance of total tumour clearance. The treatment of choice for persistent and recurrent differentiated thyroid carcinoma is surgical reintervention, if feasible, before radioiodine and radiation therapy are considered.

The concentration-time-course in serum as well as the urinary excretion of Praziquantel and metabolites were studied, in healthy volunteers, using the 14C-labelled compound, at dose levels of 14 and 46 mg/kg. The analytical methods applied comprised determination of radioactivity (Praziquantel and metabolites in toto) as well as unmetabolized drug by two specific methods (gas liquid chromatography, fluorometry).Depending on the dose, the concentration maximum of radioactivity in serum was observed 2 to 4 hrs after administration. In contrast, the concentration maximum of the unmetabolized drug was attained at 1 to 2 hrs after administration. Compared to the concentrations of 14C-radioactivity, the concentrations of unmetabolized drug were smaller by a factor of about 10 2, indicating rapid and almost complete metabolism of Praziquantel.The radioactivity was eliminated from serum with a half life of approx. 4 hours whereas the half life of unmetabolized drug was found to be approx. 1.5 hours.On the basis of the radioactivity values, 84±3% of the 14 mg/kg dose and 80±6% of the 46 mg/kg dose were found to be excreted renally within 4 days. More than 90% of the renally excreted drug was recovered within the first 24 hours.The excretion data indicate a virtually complete enteral absorption of the drug.

We investigated the natural course of subclinical thyroid dysfunctions in geriatric patients, especially regarding their association with mortality rate. Ninety-three randomly selected chronically ill geriatric patients 64- 87 (median: 77) yr of age participated in the screening study with a 2-yr follow-up. Serum thyrotropin (thyroid- stimulating hormone [TSH]), free thyroxine, triiodothyronine, and antibodies against thyroid peroxidase were measured. During the follow-up, patients with suppressed TSH levels who were otherwise euthyroid (untreated) had a higher mortality rate than patients with normal TSH (5/8 vs 18/64; p < 0.05). The initial clinical state of these two subgroups did not differ significantly. Two-thirds of patients with treated hyperthyroidism died. The mortality rate of patients with initially subnormal but not suppressed TSH level was average and did not differ statistically from either the euthyroid or the hyperthyroid groups. Only 1 of 13 euthyroid patients with positive thyroid antibody titers developed a subsequent subclinical hypothyroidism. Subclinical hyperthyroidism was found to be associated with a higher mortality rate in chronically ill geriatric patients, which justifies screening for thyroid dysfunction and treatment of subclinical hyperthyroidism. In addition, a subnormal but measurable TSH was not indicative regarding the future development of hyperthyroidism. Finally, during the 2-yr follow-up, antibody positivity in the euthyroid cases did not prove to be predictive for the subsequent development of hypothyroidism.