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R Santelices

Publications and source records attributed to R Santelices.

12 recordsLinked to original sources
PubMed1984

Low molecular weight thyroglobulin leading to a goiter in a 12-year-old girl.

We characterized the abnormal thyroglobulin (TG) in the thyroid and serum of a 12-yr-old girl with a large sporadic multinodular goiter first noted at age 4 yr. She developed normally and had no clinical evidence of hypothyroidism. However, her serum T4 was less than 1.0 microgram/dl, T3 was 125 ng/dl, and TSH was 155 microU/ml. Serum PBI was 9.7 micrograms/dl, and more than 90% was not extractable with butanol. The 24-h radioactive iodine uptake was 55%, not dischargeable by perchlorate. Hormone formation was tested by the administration of 131I before surgery. [131I]T4 and [131I]T3, but not 131I-labeled iodotyrosines, were present in the thyroidal venous blood. Hydrolysis of 10,000 X g supernatants from three randomly obtained samples of the goiter revealed 66-77% of the 131I as iodotyrosines, 2-4% as iodothyronines, and 10-12% as undigestable material; the MIT to DIT ratio ranged from 3.1-8.7, and the T4 to T3 ratio ranged from 2.3-8.3. The TG level was 2.5 mg/g in the goiter and 9.4 micrograms/ml in the serum. The RIA displacement curves for the goiter and serum TG levels were both identical to the curve produced by normal human TG. The iodine contents of goiter and serum TG were 0.49% and 0.47% (wt/wt), respectively. The T4 to T3 ratio was lower in the goiter (approximately 5) than in the serum iodoprotein (approximately 45), whereas the calculation of the T4 to T3 ratio in the thyroidal secretion was less than 1. The goiter and serum TG bound normally to Concanavalin A, indicating that they contained carbohydrate. When either serum- or goiter-soluble proteins were gel-filtered (Bio-Gel A-5m), TG immunoreactivity and stable iodine elution profiles were the same, suggesting that no significant amounts of other iodoproteins were present in the thyroid or circulation. Both serum and goiter TG elution volumes corresponded to mol wt of approximately 9 X 10(4). A sedimentation rate of 10-11 S was found for both goiter and serum TG. An abnormally low mol wt of 8.5-9.0 X 10(4) was determined by sodium dodecyl sulfate-electrophoresis, in good agreement with the estimates from gel filtration studies. A single band was present on sodium dodecyl sulfate-electrophoresis regardless of whether the TG was reduced before the analysis. Thus, it is very unlikely that the low molecular weight was due to partial hydrolysis.(ABSTRACT TRUNCATED AT 400 WORDS)

Child↗
PubMedDate not supplied

[Validation of the radioimmunoassays for pituitary gonadotropins II. Human follicle stimulating hormone (author's transl)].

The present paper summarizes the experience of the authors in the setting up of the radioimmunoassay (RIA) for human follicle simulating hormone (H-FSH), with the purified antigen for radioiodination, the F-FSH standard and the specific antibodies kindly donated by the National Pituitary Agency of the National Institutes for Arthritis, Metabolic and Digestive Diseases of the National Institutes of Health, Bethesda, MD. U.S.A. The conditions for the RIA have modified somewhat and simplified with respect to the suggested instructions accompanying the reagents. Thus, the amount of Chloramine T and the time of exposure of the labeled H-FSH (H-FSH) has been studied. It is always purified on Sephadex G-100 immediately before addition to the RIA and in this manner it may be used for up to 2 month after labeling when kept at --20 degrees C. Curves obtained at different dilutions of the H-FSH Standard, carried out with phosphosaline buffer, pH 7.4-7.8 (PBS) containing 1 % human serum albumin, or with horse plasma, of with PBS containing 0,25 % serum from non-immune rabbits (RIA Buffer) have been compared iwth those abtained by serial dilutions of sera from post-menopausal with these diluents. The most consistent results were obtained with the RIA buffer as diluent. The redisual error was smaller, and serial of dilution curves of the H-FSH standard were parallel to those of plasma and acetone precipitates of urine from post-menopausal women. Parallelism was not god using those serum. Results using PBS contianing human seum albumin were poor. PBS containing bovine serum albumin was avoided as some batches were found to interfere with the binding of the F-FSH to the antibody. The stability of the different dilutions of the H-FSH standard prepared in RIA buffer was tested. It was found that the standard curves could be prepared, pipetted into the RIA tubes and kept ready, frozen at --20 degrees C for one to two months. This shortens the actual setting up of a given RIA and decreases interassay variation of results. Parallelism of the H-FSH standard curve with serial dilutions (in RIA-buffer) of sera from women on the day of the preovulatory was confirmed. The data obtained in men and women, during stimulation with LH-RH are also given. No cross reactivity was found the HCG or sera from women, in agreement with the fact that the antiserum had been absorbed with HCG. There is, however, a considerable degree of cross reactivity with H-TSH; Thus, sera containing 15 muU/ml H-TSH or more, would give false H-FSH results. Such H-TSH values are not only found in hypothyroid patients, but might be reached during TRH responses to TRH.

Adult↗