Thyrotoxicosis in childhood.
Evidence supports the presence of a genetic predisposition to an abnormality in immune surveillance, with environmental factors precipitating the development of Graves' disease.
Child↗
Biomedical subjects
T P Foley
Publications and source records attributed to T P Foley.
The relationship between autoimmune thyroid disease and iodine intake: a review.
There is evidence to suggest that elevated levels of iodide in the diet are associated with autoimmune thyroid disease (ATD) in susceptible individuals, and that autoimmune thyroiditis (Hashimoto's disease) is less common in susceptible individuals who live in regions with dietary iodine deficiency. There are epidemiologic studies in endemic goiter areas that report an increase in ATD, particularly thyroiditis, after the therapeutic administration of iodized salt, bread and oil. Lymphocytic infiltration of the thyroid is rarely found in patients from severe endemic goiter regions, yet there is a reversal of this observation after dietary iodine supplementation. Thyroid antibodies, both thyroglobulin (TgAb) and peroxidase (TpAb) or microsomal, were not detected in serum from patients with endemic goiter, but became positive in 43% of subjects three and six months after therapy with iodized oil, and there developed transient hyperthyroidism. Similarly, the addition of iodine to the diet or the administration of iodine-containing medications increases the frequency of ATD and the severity of existing autoimmune thyroiditis. Furthermore, autoimmune thyroiditis has been induced by the administration of excess iodide to strains of chickens and rats that are genetically predetermined to develop the disease. We are beginning to understand the pathogenesis of ATD. In hyperthyroidism the evidence clearly supports the hypothesis that TSH receptor antibodies (TRAb) stimulate the TSH receptor to induce excessive and sustained secretion of thyroid hormones. Cellmediated immune mechanisms, such as antibody dependent cellmediated cytotoxicity (ADCC), initiate the lymphocytic infiltration and thyrocytotoxicity in autoimmune thyroiditis. The mechanisms that initiate the development of the abnormal immune response and the relationship of ATD with excess iodide are poorly understood. There is evidence that an increase in the iodination of thyroglobulin (Tg) enhances its immunogenicity. The results of clinical and experimental studies support the requirement of a genetic predisposition to the development of ATD that may be precipitated by exposure to certain environmental factors. Another mechanism supported by experimental data is the direct toxic effect of excess iodide on iodide-deficient thyroid glands. High concentrations of iodide after oxidation to iodine causes epithelial necrosis and inflammation associated with lipofuscin accumulation suggestive of toxicity mediated by lipid peroxidation from excessive amounts of free radicals. The epithelial damage would initiate inflammatory and immune responses. Although these mechanisms would relate to the onset of autoimmune thyroiditis on exposure to excessive amounts of iodide, the relationship of iodide intake and autoimmune hyperthyroidism is less clear.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Spondylo-metaphyseal dysplasia Algerian type: confirmation of a new syndrome.
We report on a further case of a recently described type of spondylo-metaphyseal dysplasia in a 12(10/12)-year-old Polish boy. The original paper described the disorder in five relatives in an Algerian family.
Body Height↗
Maternally transferred thyroid disease in the infant: recognition and treatment.
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Female↗
Effects of perinatal undernutrition on elimination of immature myosin isoforms in the rat diaphragm.
The effect of perinatal undernutrition on the postnatal elimination of immature myosin isoforms in rat diaphragm muscle was examined using electrophoretic and immunocytochemical techniques. Electrophoresis of native myosin showed that neonatal bands were present in diaphragm muscles of both control and undernourished rats on day 4. By day 21, the neonatal bands were diminished in the control diaphragm compared with the diaphragm of the undernourished rats. Neonatal bands persisted on postnatal day 30 in the diaphragm of the undernourished rats but not in the diaphragm of control rats. No significant difference in the time course of elimination of embryonic myosin light chain (LCemb) was observed between the diaphragm muscles of control and undernourished rats with two-dimensional gel electrophoresis. Immunocytochemical analysis demonstrated embryonic myosin heavy chain (MHCemb) in all myofibers of the diaphragm muscle of both groups at day 4, but this isoform was not detected in either group by day 14. Reactivity with anti-neonatal myosin heavy chain (MHCneo) indicated that rate of elimination of the MHCneo was delayed in the undernourished state as compared with the normal rats (P less than 0.001). Serum triiodothyronine levels were measured at 14, 21, and 30 days and were significantly lower in the undernourished rats compared with age-matched controls. These data demonstrate that the normal postnatal decrease in MHCneo, but not MHCemb or LCemb, is affected by the nutritional state of the animal. We speculate that these alterations in myosin isoform transitions are induced by hypothyroidism associated with undernutrition.
Aging↗
Sonographic findings in maternal hyperthyroidism. Fetal hyperthyroidism/fetal goiter.
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Adult↗
Longitudinal assessment of L-thyroxine therapy for congenital hypothyroidism.
We evaluated the longitudinal response in 43 infants with congenital primary hypothyroidism during the first year of L-thyroxine therapy. Diagnosis was confirmed by serum thyroid hormone measurements by 4 weeks of age in 38 infants and between 40 and 80 days of age in the remainder. This group of infants was divided by radionuclide thyroid imaging into 34 infants with thyroid dysgenesis and nine with dyshormonogenesis. The group with thyroid dysgenesis was subdivided into 21 infants with athyreosis and 13 with residual thyroid tissue (11 ectopic and 2 hypoplastic glands). L-Thyroxine therapy, at an average dose of 10 to 14 micrograms/kg/day, was begun immediately after diagnosis, and serum concentration of total thyroxine, free thyroxine, triiodothyronine, reverse triiodothyronine, and thyroid-stimulating hormone were determined serially. Serum concentration of total and of free thyroxine became normal within 1 week of the start of therapy in all groups. Despite a similarly mild degree of hypothyroidism at diagnosis observed in infants with dyshormonogenesis or with ectopia or hypoplasia, those with dyshormonogenesis had a more sensitive response to initial thyroid hormone replacement than did patients with thyroid dysgenesis, as judged by L-thyroxine does and thyroid-stimulating hormone suppression. We conclude that the prompt restoration of clinical and biochemical euthyroidism during early infancy with doses of L-thyroxine between 10 and 14 micrograms/kg/day is a safe and effective method of therapy for children with congenital hypothyroidism.
Congenital Hypothyroidism↗
Juvenile Graves disease: usefulness and limitations of thyrotropin receptor antibody determinations.
Thyrotropin receptor antibodies (TRAb) were measured in serum from 49 patients with active and inactive juvenile Graves disease, and the results were compared with values from control subjects and patients with Hashimoto disease. With a thyrotropin binding inhibition immunoglobulin (TBII) assay, TRAb were found in serum from 25 (93%) of 27 patients with untreated, active Graves disease. The TRAb values remained positive in 20 (72%) of 29 patients during the first 6 months of antithyroid therapy and in 13 (54%) of 24 patients during the second 6 months. After discontinuation of antithyroid therapy, 15 patients experienced 18 episodes of relapse of thyrotoxicosis; during relapse TRAb values were positive in all but one patient. Among 19 patients who remained clinically and biochemically euthyroid after cessation of antithyroid therapy, TRAb were not detected in 28 (78%) of 36 serum specimens. Of the eight positive values from six patients, no antiidiotypic antibodies were found, and thyroid stimulating immunoglobulins (TSI) were not detected in four specimens. The TRAb determination correctly predicted the subsequent clinical course in 26 (72%) of 36 patients. Furthermore, TRAb values and results of triiodothyronine suppression tests were in agreement in 27 of 36 patients, or 75% of the time. TSI were present in serum from only 19 (73%) of 26 patients with active disease; however, TSI were negative in all patients with inactive Graves disease. During the management of Graves disease, TRAb measurements by TBII determinations are valuable in the diagnosis of active disease, assist in the decision to discontinue antithyroid drug therapy, and are useful as the T3 suppression test to predict the clinical course of the disease. The TSI measurement is most useful to determine the activity of the disease when TRAb values are positive in a euthyroid patient.
Adolescent↗
Clinical studies with recombinant-DNA-derived methionyl human growth hormone in growth hormone deficient children.
Thirty-six children with growth hormone deficiency were treated for up to 48 months with methionyl human growth hormone (hGH) synthesised by DNA recombinant methods. The growth rate for these children increased from 3.2 +/- 1.1 cm/yr to 10.5 +/- 2.2 cm/yr (mean +/- SD). This was similar to the effect of pituitary hGH in ten GH deficient children, 3.8 +/- 1.0 to 10.1 +/- 1.1 cm/yr. Serum somatomedin C rose from 0.26 +/- 0.23 U/ml to 0.79 +/- 0.53 U/ml after 6 months of methionyl-hGH therapy, similar to the effect of pituitary hGH. The incidence of antibody formation to methionyl-hGH was higher than that observed with pituitary hGH (Kabi) but poor growth was observed only in the one patient on methionyl-hGH who acquired high-titre high-binding-capacity antibodies to hGH. No consistent changes in levels of antibodies to Escherichia coli proteins were detected. No other allergic manifestations or systemic side-effects were demonstrable.
Adolescent↗
Growth hormone therapy for patients with Turner's syndrome.
The linear growth of 8 patients with Turner's syndrome during human growth hormone (GH) administration was documented. Mean growth velocity was significantly greater during GH treatment (4.9 +/- 0.8 cm/year) than before treatment (3.3 +/- 0.8 cm/year, p less than 0.001). Growth velocity was related to dosage but not correlated with chronologic age, skeletal age or weight.
Adolescent↗
Growth hormone therapy and tumor recurrence. Findings in children with brain neoplasms and hypopituitarism.
We report the outcome of growth hormone (GH) therapy in 34 children (17 boys and 17 girls) with brain tumors in whom hypopituitarism developed. The types of tumors included the following: craniopharyngiomas (18); germinomas (four); astrocytomas (three); chromophobe adenomas (three); medulloblastomas (two); glioma (one); dermoid (one); retinoblastoma (one); and metastatic rhabdomyosarcoma from the pelvis (one). Ninety-four percent of the patients were GH deficient post-tumor therapy, which consisted of surgery with and without radiotherapy. Twenty-four of 34 patients received GH. Eight of 24 patients receiving GH had recurrence of tumor; 16 were tumor free eight to 72 months after initial therapy. Eleven patients had 12 recurrences. Patients with tumor recurrence had a considerably lower growth rate during the first year of GH therapy than those without recurrence (mean, 3.5 +/- 1.3 cm/yr v 6.2 +/- 2.5 cm/yr). Three of 11 patients with recurrence had not received GH therapy; however, one was receiving testosterone intramuscularly monthly at the time of a second recurrence. Thus, 24 of 34 patients with brain tumors and hypopituitarism received GH therapy. Eight (33%) of 24 had tumor recurrence, compared with three (30%) of ten who did not receive GH. The data suggest that GH therapy is probably not associated with increased rate of tumor recurrence.
Adolescent↗
Growth hormone releasing hormone and growth hormone: genetic studies in familial growth hormone deficiency.
Four families with growth hormone (GH) deficiency, either isolated or with other pituitary hormonal deficits are described. Members of each underwent pharmacological testing for GH secretion and infusions of GH releasing hormone (GHRH) to determine the locus of the defect in GH secretion. In addition, we have extracted DNA from white blood cells to characterize the GHRH and GH genes. All members tested had the normal complement of GH and GHRH genes. Four generations of one family with isolated GH deficiency, autosomal dominant were studied. The younger members showed minimal GH responsiveness to a single infusion of GHRH. However, the older members did not respond even after 30 doses of GHRH given intravenously every 3 h. Two members of a family with the autosomal recessive type of isolated GH deficiency had large GH increases after GHRH infusion. Thus in these families the GH secretory defect lies within the hypothalamus. Members of two families with pituitary deficiency (GH and other tropic hormones) of the autosomal recessive type had variable responses to GHRH and varying amounts of pituitary tissue seen on high resolution CT scans. Although it is not possible to delineate the precise location of the secretory defects in these latter two families, a hypothalamic defect is probable based on the responses to multiple trophic stimuli. Heterogeneity of structure and function exists within and between families with isolated GH deficiency and within and among families with pituitary deficiency. It is from the study of such families in which all members presumably have the same underlying defect that one can more readily decide on a pathogenetic mechanism.
Adolescent↗
Women, men, and examination scores.
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Adult↗
Production of an insulin-like growth factor by osteosarcoma.
To test the possibility that osteosarcoma cells produce their own growth factors, we measured levels of insulin and somatomedin C (SMC), an insulin-like growth factor, in culture media of two cell lines derived from patients with that disease. SMC but not insulin levels increased three- to ten-fold over a period of 7 days paralleling the increases in cell number. Production of SMC was inhibited by cycloheximide.
Cell Division↗
Comparison of physiologic and pharmacologic assessment of growth hormone secretion.
To determine if pharmacologic and physiologic tests are equally effective in the assessment of growth hormone (GH) secretory status, serum GH levels were measured during sequential tests with intravenous arginine infusion and insulin-induced hypoglycemia (arginine-insulin tolerance test [ AITT ] ) and during sleep in 62 children, aged 2.1 to 17.3 years. Responses during AITT and sleep were concordant in 53 patients and discordant in nine patients. Arginine-insulin tolerance test results were consistent with the subsequent clinical course in 80% of the patients while nocturnal sampling was consistent with the subsequent clinical course in 93% of the patients. Thus, the failure of a normal serum GH response to pharmacologic stimuli is not always a diagnostic indicator of GH deficiency. Additional investigation of discordant GH responses to pharmacologic and physiologic stimuli may lead to a further understanding of the control mechanisms of GH secretion.
Adolescent↗
Characterization of somatostatin specific binding in plasma cell membranes of human placenta.
Somatostatin is a known inhibitor of hormone secretion and of nutrient transport. Because somatostatin-like immunoreactivity has been detected in amniotic fluid and the placenta has both hormone secretory and nutrient transport functions, we investigated the possible existence of somatostatin receptors on placenta cell membranes. Binding of 125I-Tyr1- and 125I-Tyr11-somatostatin (5-21%) to solubilized placenta cell membranes was observed. Binding was time-, temperature-, and pH-dependent and occurred maximally with incubation at concentrations of 25 micrograms of membrane protein. Displacement of binding of 125I-Tyr1 and Tyr11 somatostatin by cold cyclic and linear somatostatin and somatostatin analogs Ala-5, Ala-8, and Ala-11 was observed. Scatchard analysis of data revealed high capacity of (Ro 0.44 mol/micrograms X 10(-12) but low affinity (Kd 1.8 M X 10(-7) binding sites similar to that reported in other tissues. Binding was not reversible under our experimental conditions. The significance of this low affinity binding of somatostatin to placenta cell membranes remains to be determined.
Binding, Competitive↗
Human serum spreading factor: relationship to somatomedin B.
Human serum spreading factor (SF) is a blood glycoprotein that promotes the attachment and spreading of a variety of cell types in serum-free culture, as well as affecting migration, proliferation and differentiation of some cell types under appropriate conditions. The amino acids occupying 17 of the first 23 positions from the NH2-terminus of SF were determined, and this sequence was found to be identical to that reported for somatomedin B (SmB) by Fryklund and Sievertsson (FEBS Letters 87:55). Immunoassay of SF in plasma from subjects with conditions related to altered GH levels indicated that serum SF levels were not GH-responsive to any marked degree. No effect of purified SF was observed in a cell growth assay used previously to detect mitogenic activity in SmB preparations. These results support the conclusion that SF acts as a substratum molecule to elicit its biological effects in cell culture, and does not act in a manner similar to peptide growth factors. These data also are consistent with the conclusion of Heldin et al. (Science 213:1122) that the mitogenic activity of SmB preparations is derived from a contaminating factor, and is not due to SmB.
Amino Acid Sequence↗