RESUMEN
We have examined the ability of IgGs obtained from 8 endemic cretins to inhibit TSH-stimulated thyroid cell growth in culture. Clinical and laboratory evidence for hypothyroidism was present in six subjects; the two remaining patients had borderline low serum T4, normal T3 and exaggerated TSH response to TRH. In six patients 2 mg IgG exhibited an inhibitory effect in the cellular growth expressed by a diminished incorporation of 3H-thymidine into the DNA of TSH-stimulated FRTL-5 cells (range: 26-87% inhibition). Seven patients presented clinically with thyroid atrophy of relatively small thyroid enlargements for the degree of chronic iodine deficiency that was present in the area. The remaining subject had a large multinodular goiter and IgG purified from this patient had no inhibitory effect in the FRTL-5 cellular growth. A direct relationship was noted between the degree of thyroid growth inhibition (%) and the basal serum TSH concentration. We conclude that the presence of thyroid growth inhibiting immunoglobulin may be related to the absence of thyroid growth or even thyroid atrophy in endemic cretins.
Asunto(s)
Hipotiroidismo Congénito/inmunología , Inmunoglobulinas/inmunología , Glándula Tiroides/patología , Tirotropina/antagonistas & inhibidores , Adolescente , Adulto , Atrofia/patología , Brasil , División Celular/efectos de los fármacos , Línea Celular/efectos de los fármacos , Hipotiroidismo Congénito/patología , Femenino , Crecimiento/efectos de los fármacos , Humanos , Masculino , Tirotropina/farmacologíaRESUMEN
We designed an in vitro assay to detect the presence of lactose in the tracheal aspirates of premature, ventilator-dependent infants. This method was employed to identify recurrent, unrecognized aspiration, which could prolong the requirements for ventilator support and contribute to the development of chronic lung disease. One hundred five determinations of lactose were performed on the tracheal fluid obtained from 42 ventilator-dependent infants who were receiving enteral feedings. There was a wide range of lactose levels (0 to 3,270 nmol lactose/ml tracheal aspirate). Six infants had samples that were highly suggestive of aspiration (greater than 200 nmol lactose/ml tracheal aspirate). Twenty infants had questionably positive samples (25 to 200 nmol lactose/ml tracheal aspirate), and 16 infants had samples that were considered negative for aspiration (less than 25 nmol lactose/ml tracheal aspirate).