Measurement of telomerase activity in clinically obtained tumor samples may provide important information for use as both a diagnostic marker and a prognostic indicator for patient outcome. In order to evaluate telomerase activity in tumor tissue without radiolabeling the product, we developed a simple telomeric repeat amplification protocol-silver-staining assay that is less time-consuming, is safe and requires minimal equipment. In addition, we determined the sensitivity of the silver-staining method by using extracts of telomerase-positive thyroid carcinoma cell lines which were serially diluted from 5,000 to 10 cells. Telomerase activity was also assayed in 19 thyroid tumors, 2 normal controls and 27 bone marrow aspirates. The results indicate that the technique permits the detection of telomerase activity from 5000 to as few as 10 cells. We propose that it could be immediately applicable in many laboratories due to the minimal amount of equipment required.

Estradiol has well-known indirect effects on the thyroid. A direct effect of estradiol on thyroid follicular cells, increasing cell growth and reducing the expression of the sodium-iodide symporter gene, has been recently reported. The aim of the present investigation was to study the effect of estradiol on iodide uptake by thyroid follicular cells, using FRTL-5 cells as a model. Estradiol decreased basal iodide uptake by FRTL-5 cells from control levels of 2.490 ± 0.370 to 2.085 ± 0.364 pmol I-/µg DNA at 1 ng/ml (P<0.02), to 1.970 ± 0.302 pmol I-/µg DNA at 10 ng/ml (P<0.003), and to 2.038 ± 0.389 pmol I-/µg DNA at 100 ng/ml (P<0.02). In addition, 4 ng/ml estradiol decreased iodide uptake induced by 0.02 mIU/ml thyrotropin from 8.678 ± 0.408 to 7.312 ± 0.506 pmol I-/µg DNA (P<0.02). A decrease in iodide uptake by thyroid cells caused by estradiol has not been described previously and may have a role in goiter pathogenesis.

OBJETIVO: Comparar em recém-nascidos (RN) duas estratégias diferentes para o rastreamento do hipotiroidismo congênito (HC), a dosagem primária de TSH no sangue colhido do cordão umbilical (método 1) e a dosagem primária de T4 no sangue colhido por punção de calcanhar no 2º dia de internação (método 2). MÉTODOS: Os autores compararam as duas estratégias em 10.000 RN. Dosaram o TSH por método imunofluorimétrico sensível em papel de filtro e o T4 por radioimunoensaio em papel de filtro. A coleta de sangue do calcanhar foi realizada no 2º dia de vida RESULTADOS: Os dois programas diagnosticaram todos os casos de HC nos RN (4 casos, 1/2.500 RN). O índice de rechamada por coleta inadequada foi nulo no método 1 e de 8,5% (850 RN) no método 2. O índice de reconvocação para confirmação de resultados foi de 0,06% (6 RN) no método 1 e de 2,25% (225 RN) no método 2; quando este método incluía também a dosagem suplementar de TSH, o índice baixou para 1,63% (163 RN). CONCLUSÃO: Os dados dos autores evidenciam a superioridade técnica da coleta de sangue a partir do cordão umbilical em relação à punção de calcanhar, assim como da dosagem primária de TSH em relação à de T4, uma vez que apresentam índices muito menores de reconvocação.

OBJECTIVE: Compare two different strategies in newborn screening for congenital hypothyroidism, primary TSH in the umbilical cord blood (method 1) and primary T4 in blood collected from the heel in the 2nd day of life (method 2). METHODS: We compared both strategies in 10,000 newborns, measuring TSH by a sensitive immunofluorimetric assay and T4 by a radioimmunoassay. RESULTS: Both strategies detected all cases of hypothyroidism (4 cases, 1/2,500 newborns). The recalling index owing to insufficient amount of blood to perform the assays was zero in method 1 and 8.5% (850 newborns) in method 2. The recalling index for confirmation of the results was 0.06% (6 newborns) in method 1 and 2.25% (225 newborns) in method 2; when method 2 included supplementary TSH, the recalling index was reduced to 1.63% (163 newborns). CONCLUSION: Our data indicate the technical superiority of the umbilical cord blood compared to heel and primary TSH compared to primary T4 in the neonatal thyroid screening for congenital hypothyroidism.

Os valores das dosagens de T3 e de T4 diferenciaram os pacientes com boa e má evolução durante a internação em unidade de terapia intensiva. OBJETIVO. Procurar indicadores para o prognóstico de doentes graves por meio do estudo seqüencial dos níveis séricos dos hormônios tiroidianos. MÉTODOS. Os autores mediram as iodotironinas (T3, T4 e rT3) por ocasião da entrada e da alta de 42 pacientes internados em unidade de terapia intensiva. Verificaram, também, os dados referentes à última coleta de outros 17 doentes, transferidos para a UTI após o início do quadro clínico. RESULTADOS. Comparando pacientes que evoluíram bem com aqueles que foram a óbito, observaram, nos primeiros, níveis iniciais normais de T4 em 76% dos casos, valores que se mantiveram estáveis ou se elevaram em 65% dos pacientes durante a internação, de tal forma que níveis normais de T4 estavam presentes em 70% dos casos por ocasião de sua alta. Ao contrário, 56% dos pacientes que evoluíram mal já apresentavam T4 inicial baixo, que diminuiu ainda mais em 95% dos pacientes durante a internação, notando-se valores baixos em 81% dos casos por ocasião da última amostra. Os valores de T3 e de T4 em conjunto também diferenciaram os pacientes com boa e má evolução. CONCLUSÃO. Os autores sugerem que a observação dos níveis séricos das iodotironinas pode oferecer importante subsídio na avaliação prognóstica de doentes em estado grave.

In order to find prognostic parameters in patients with severe diseases, we analyzed sequentially the levels of thyroid hormones. METHODS. We measured iodothyronines (T3, T4 and rT3) in 42 patients before the admission and after the discharge in an intensive care unit. In addition, we also measured the iodothyronines in other 17 patients after the discharge. RESULTS. Comparing the group of good outcome with the patients who died, we observed in the former group initial normal T4 levels in 76% of the patients, which were maintained in 65% of them during hospitalization and in 70% of them at the time of delivery from the intensive care unit. Patients who died, however, presented initial low T4 levels in 56% of them, decreasing values in 95% of them during hospitalization and low levels in 81% of patients at the last dosage. The combined profile of T3 and T4 also differentiated good and bad outcome. CONCLUSION. We suggest that serial analysis of serum levels of thyroid hormones may help the evaluation of critical care patients.