ABSTRACT
A multicentre study was undertaken to assess the cytogenetic damage to peripheral blood lymphocytes in 31 patients treated with 131I for thyrotoxicosis using the cytokinesis-blocked micronucleus assay. The results were compared to those for eight thyroid carcinoma patients using the same method. For each patient, blood samples were taken immediately before and 1 week after iodine administration. The first blood sample was divided into three fractions and each fraction was subsequently irradiated in vitro with 0, 0.5 and 1 Gy 60Co gamma rays, respectively. After blood culture for 70 h, cells were harvested, stained with Romanowsky-Giemsa and the micronuclei scored in 1000 binucleated cells. For both patient groups, a linear-quadratic dose-response curve was fitted through the data set of the first blood sample by a least squares analysis. The mean increase in micronuclei after 131I therapy (second blood sample) was fitted to this curve and the mean equivalent total body dose (ETBD) calculated. Surprisingly, in view of the large difference in administered activity between thyroid carcinoma patients and thyrotoxicosis patients, the increase in micronuclei after therapy (mean +/- S.D.: 32 +/- 30 and 32 +/- 23, respectively) and the equivalent total body dose (0.34 and 0.32 Gy, respectively) were not significantly different (P > 0.1). The small number of micronuclei induced by 131I therapy (32 +/- 29), compared with external beam radiotherapy for Hodgkin's disease (640 +/- 381) or cervix carcinoma (298 +/- 76) [1], gave a cancer mortality estimate of less than 1%. This also explains why late detrimental effects in patients after 131I treatment have not been reported in the literature.
Subject(s)
Iodine Radioisotopes/adverse effects , Thyrotoxicosis/radiotherapy , Adult , Aged , Aged, 80 and over , Dose-Response Relationship, Radiation , Female , Half-Life , Humans , Iodine Radioisotopes/pharmacokinetics , Iodine Radioisotopes/therapeutic use , Male , Micronucleus Tests , Middle Aged , Radiometry , Radionuclide Imaging , Risk Assessment , Thyroid Gland/diagnostic imaging , Thyroid Neoplasms/diagnostic imaging , Thyrotoxicosis/complicationsABSTRACT
A new two-site immunoenzymometric method using monoclonal antibodies was developed for measuring CK-BB mass concentrations in cerebrospinal fluid (CSF). Within- and between-assay coefficient of variation values for the method varied between 6 and 9%. Assay results are not affected by presence of sulfate and sialic acid groups on the enzyme. In comparison to catalytic activity measurements, a steady decline in the enzyme's specific activity was observed after acute head trauma. Repetitive measurements of CK-BB mass concentration in cerebrospinal fluid during the first 24 h after trauma enabled the estimation of brain lesion size. Clinical outcome of acute head trauma patients evaluated by Glasglow Outcome Scale, correlated well with cumulative CK-BB release after trauma. Also in neonates, CK-BB determinations in CSF correlated well with clinical findings.
