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Biomedical subjects

D H Solomon

Publications and source records attributed to D H Solomon.

At least 163 records · Page 9Linked to original sources
PubMed1977

Assays for antigen-stimulated lymphocyte-derived migration enhancement and inhibition factors from patients with thyroid diseases and their relatives.

Cell-mediated immunity to thyroid antigens was studied by means of an assay for antigen-stimulated leukocyte migration inhibition factor (LIF) in 5 groups of subjects: patients with Graves' disease, Hashimoto's thyroiditis, their relatives and normal controls. We also sought evidence for the possibility that the hypothesized migration enhancement factor (MEF) might be produced by lymphocytes from patients with autoimmune disorders. We found little evidence of LIF production and none of MEF production by the leukocytes of patients with autoimmune thyroid diseases upon exposure to thyroid antigens. Similarly, either no or only minimal amounts of LIF were demonstrated in culture supernatants of leukocytes of their immediate relatives.

Antibodies↗
PubMed1976

Human thyroid adenyl cyclase-stimulating activity in immunoglobulin G of patients with Graves' disease.

UNLABELLED: We have studied the characteristics of the stimulation of adenyl cyclase (AC) activity in human thyroid plasma membranes by thyroid-stimulating hormone (TSH) and by immunoglobulin G (IgG) from the sera of patients with Graves' disease. AC activity was measured as adenosine 3',5'-cyclic monophosphate (cAMP) generated by membranes in a 10 minute incubation. IgG from two patients with Graves' disease possessed particularly potent human thyroid AC-stimulating activity; the dose-response curves with these IgGs were essentially parallel to those obtained with TSH. As little as 30 mug of the IgG of one patient with Graves' disease or 8 muU of TSH caused significant AC stimulation. A Lineweaver-Burk plot of the data suggested similarity in the site of action of both TSH and human thyroid adenyl cyclase stimulator (HTACS) in Graves' IgG. Submaximal doses of HTACS and TSH had additive effects on AC stimulation, but a large dose of a Graves' IgG with potent AC stimulating activity did not enhance AC stimulation by a maximal dose of TSH. The effect of HTACS on AC was slower in onset and longer in duration than an equipotent dose of TSH. HTACS was detectable in IgGs of 9 of 15 untreated hyperthyroid Graves' disease patients; its concentration, however, did not correlate significantly with tests of thyroid function, nor with long-acting thyroid stimulator (LATS) activity. In another 11 treated patients with Graves' disease, selected for the presence of LATS, HTACS and LATS were significantly correlated. We observed no inhibition of LATS activity in a Graves' IgG chosen for such testing because of its high titer of HTACS and no detectable LATS. However, an inhibitor of HTACS was detected in 2 of 4 IgGs; one of these two IgGs also inhibited AC stimulation by TSH. CONCLUSIONS: 1) Some Graves' disease IgGs contain a human thyroid AC stimulator (HTACS), probably different from LATS. 2) HTACS may act via a common pathway with TSH; it differs from TSH, however, in having a slower onset and a greater effect during more prolonged incubation with plasma membranes. 3) There is also an inhibitor of HTACS activity in some Graves' disease IgGs.

Adenylyl Cyclases↗
PubMed1976

A radioimmunoassay for measurement of 3,3'-L-diiodothyronine (T2).

A sensitive, specific and reproducible radioimmunoassay (RIA) for measurement of 3,3'-L-diiodothyoride (T2) in concentrated ethanol extracts of serum and amniotic fluid is described. The T2 binding antiserum was prepared aby immunization of rabbits with T2-human serum albumin conjugate. Of various thyroid hormone derivatives tested, only 3-L-monoiodothyonine cross-reacted significantly with T2 binding sites on the antiserum...

Amniotic Fluid↗
PubMed1975

Evidence for normal thyroidal adenyl cyclase, cyclic AMP-binding and protein-kinase activities in Graves' disease.

The adenyl cyclase, cAMP-binding and protein-kinase activities have been studied in thyroid glands from patients with Graves' disease in comparison with normal thyroid glands. The basal and TSH-stimulated adenyl cyclase activities were tested in crude plasma membrane preparations. The characteristics of the intracellular binding of cAMP, i.e., the maximal binding capacity (MBC) for cAMP and affinity constant (Ka) of the binding, and the basal and cAMP-stimulated protein-kinase activities, were estimated in both the soluble and particulate fractions of thyroid tissue. All of these parameters studied were essentially normal in Graves' disease. It is concluded that hyperthyroidism in Graves' disease is probably not a result of qualitative or quantitative abnormalities in the adenyl cyclase-cAMP protein-kinase system.

Adenylyl Cyclases↗
PubMed1975

Acute effects of corticosteroids on thyroid activity in Graves' disease.

We studied the effects of administration of dexamethasone, 2 mg orally every 6 hr for 4 doses, on circulating thyroid hormone levels in hyperthyroid Graves' disease patients and in normal subjects. Serum triiodothyronine (T3), thyroxine (T4) and thyroglobulin (Tg) fell significantly below baseline values within 24 to 48 h after the first dose of dexamethasone in hyperthyroid patients; the values returned to or toward baseline levels in the subsequent 5 to 6 days. Serum T3 fell transiently in normals but to a much smaller degree than in hyperthyroid patients; T4 and Tg showed no significant change. Dexamethasone had ni inhibitory effect on the thyroid response to exogenous TSH in the hyperthyroid patients. Studies in vitro demonstrated lack of any appreciable effect by dexamethasone or hydrocortisone on stimulation of human thyroid adenyl cyclase by TSH or immunoglobulin G(IgG) from patient with Graves' disease. The fall in serum T3 without a change in serum T4 in normals suggested an effect of dexamethasone on peripheral conversion of T4 to T3. However, the markedly greater, more persistent drop in T3 in the hyperthyroid patients, as well as the associated drop in T4 and Tg, suggested an additional effect of dexamethasone administration on thyroid secretion in these patients. Preservation of thyroidal response to TSH during dexamethasone administration both in vivo and in vitro indicated that dexamethasone had not impaired thyroidal cellular processes per se. The data were consistent with an effect of dexamethasone on thyroid stimulator. The putative stimulator does not appear to be normal pituitary thyrotropin (TSH), since TSH was not detected in serum of anyof the patients studied. Additionally, the changes observed were too rapid to be explained by a steroid-induced fall in the level of a circulating IgG thyroid stimulator. The data are consistent with the possibility that there may be a non-TSH non-IgG thyroid stimulator in Graves' disease.

Adolescent↗
PubMed1975

Opposite effects of dexamethasone on serum concentrations of 3,3',5'-triiodothyronine (reverse T3) and 3,3'5-triiodothyronine (T3).

Dexamethasone, 2 mg every 6 hours for 4 doses, was given to 4 hypothyroid patients receiving treatment with synthetic thyroxine (T4) and to 8 untreated hyperthyroid patients with Graves' disease, and serum concentrations of thyroid hormones were measured by radioimmunoassays. Serum concentration of 3,3'5'-triiodothyronine (reverse T3, rT3) increased appreciably within 8 hours after the first dose of dexamethasone, was maximum at 24-32 hours after beginning dexamethasone, and remained elevated for about 24 hours after discontinuing the steroid. The mean baseline serum rT3 was 58 ng/per 100 ml in treated hypothyroid patients and 119 ng per 100 ml in patients with Graves' disease; the corresponding maximal post-dexamethasone serum rT3 values were 87 and 170 serum concentration of 3,3',5-triiodothyronine (T3) decreased. The decrease in serum T3 was significant at about 24 hours after beginning dexamethasone and was maximal at about 30 hours in both groups of cases under study. The decrease in serum T3 persisted in treated hypothyroid cases for about 24-48 hours and in Graves' disease cases as long as studied, at least 5 days after discontinuing hexamethasone. The changes in serum rT3 and T3 could not be attributed to the effect of dexamethasone on serum protein binding of the iodothyronines because the dialyzable fractions of rT3 and T3 following steroid administration were not different from those before it. Serum T4 did not change appreciably in treated hypothyroid cases, but decreased in Graves' disease cases from a mean baseline value of 23.5 mug per 100 ml to 18.4 mug per 100 ml 3 days after beginning dexamethasone. In addition, 3 hyperthyroid cases were studied before, during, and after administration of dexamethasone, 2 mg every 6 h for 5 days. Serum rT3 increased again as noted above and the increase persisted until about 24 hours after the last dose of the steroid. Serum T3 decreased considerably and remained decreased as long as studied, at least 4 days after discontinuing the steroid. Serum T4 decreased appreciably in 2 of the 3 cases studied. The data suggest that 1) conversion of T4 to T3 and to rT3 may occur via two distinct pathways in the metabolism of T4; 2) the changes in serum rT3 and T3 observed in our study may be due in part at least to a steroid-induced 'shift' in the metabolism of T4 whereby conversion of T4 to T3 is diminished and that to rT3 is enhanced; 3) in addition to the effect on peripheral metabolism of T4, steroids appear to reduce the circulating thyroid hormones in Graves' disease by another mechanism, probably by reduction in thyroid secretion.

Adult↗
PubMed1975

Reciprocal changes in serum concentrations of 3,3',5-triiodothyronine (T3) in systemic illnesses.

Serum concentrations of 3,3',5'-triiodothyronine (reverse T3, rT3) were measured in adult patients with several systemic illnesses whose serum total and/or free T3 were low, serum total T4 was low or normal, and free T4 was either normal or elevated. The mean serum rT3 was 76, 46, and 77 ng per 100 ml in patients with hepatic cirrhosis, chronic renal failure, and acute febrile illnesses, respectively; the values in patients with hepatic cirrhosis and acute febrile illness were significantly higher than, and values in patients with renal failure did not differ significantly from, the mean serum rT3 (41 ng per 100 ml) in normal subjects. The mean serum rT3 in another group of patients from Calcutta, India, who had severe protein calorie malnutrition (PCM), was 53 ng per 100 ml; it was significantly higher than the corresponding value, 22 ng per 100 ml, in the same patients after feeding treatment. Mean serum rT3 in patients with systemic illnesses was not so high as that (151 ng per 100 ml) in the normal newborn, who also has low serum T3 and normal or high T4. High serum rT3 in patients with systemic illness could not be attributed to increased serum protein binding of rT3; whenever studied, the dialyzable fraction of rT3 was not decreased but actually increased. The mean serum-free rT3 was 450,207, and 366 pg per 100 per 100 ml in patients with hepatic cirrhosis, chronic renal failure, and acute febrile illnesses, respectively; each of these values was significantly higher than the corresponding value, 98 pg per 100 ml, in normal subjects. The mean serum free rT3, 516 pg per 100 ml, in newborn cord sera was similar to that in patients with hepatic cirrhosis but was higher than that observed in patients with chronic renal failure and acute febrile illnesses. High serum rT3 and low serum T3 in patients with PCM improved to normal or towards normal after feeding treatment. Since the peripheral metabolism of T4 is normally the predominant source of T3 as well as rT3 in man, our data, demonstrating reciprocal changes in serum rT3 and T3 and no consistent change in serum T4, suggest that body metabolism of T4 may be so altered in systemic illness that the conversion of T4 to rT3 may be increased while that to T3 is decreased. The mechanism or the biological significance of such a diversion of T4, from the normally occurring conversion to highly potent T3, to the generation of poorly calorigenic rT3 in systemic illness, is not clear at this time. The data in patients with PCM demonstrate, however, that such a change in the metabolism of T4 can be reversible.

Acute Disease↗
PubMed1973

Neutralizing and non-neutralizing antibodies to bovine thyroid-stimulating hormone and its subunits.

To test the possibility that the long-acting thyroid stimulator (LATS) might represent an immune complex either of thyroid-stimulating hormone (TSH) with anti-TSH or of a subunit of TSH with an appropriate antibody, we immunized rabbits with bovine TSH (bTSH), bLH (luteinizing hormone), and their alpha and beta subunits (bTSHalpha and bTSHbeta). Binding, neutralizing, and nonneutralizing antibodies were demonstrated in the antisera obtained. First, antisera to TSH, TSHbeta, and TSHalpha all bound [(125)I]TSH and [(125)I]TSHbeta. Anti-bTSHbeta antisera bound [(125)I]bTSHbeta better than did anti-TSH sera, while the binding of [(125)I]bTSH was similar with both types of antiserum. Second, the thyroid-stimulating activity (McKenzie bioassay) of TSH could be neutralized by incubation with various dilutions of anti-TSH or anti-TSHbeta. Finally, when incubation mixtures containing TSH and dilutions of anti-TSHbeta antisera that only partially neutralized TSH were treated with an antiserum against rabbit immunoglobulins to precipitate immune complexes, the bioassay response of the TSH was abolished. This phenomenon was not observed when antiserum to the intact hormone was substituted in the incubation mixture. The removal of TSH biological activity from a mixture of TSH and anti-bTSHbeta by addition of an anti-immunoglobulin indicated that biologically active immune complexes were formed between TSH and anti-TSHbeta but not between TSH and anti-TSH. The time-course of the bioactivity and several other characteristics of these complexes differentiate them from LATS.

Animals↗
PubMed1973

The effects on rabbits of immunization with bovine thyroid-stimulating hormone and its subunits.

Rabbits were immunized with bovine thyroid-stimulating hormone (bTSH), bovine Inteinizing hormone (bLH), and their subunits. In two immunization experiments, thyroid-stimulating activity was found in the serum of 6 out of 12 rabbits immunized with bTSHbeta subunits. The thyroid-stimulating activity in the anti-bTSHbeta sera was greater at 2 h than at 8, was eluted with the globulin fraction from Sephadex G-100, was completely neutralized by both anti-bTSH and anti-rabbit gamma globulin, and was completely suppressed by administration of triiodothyronine (T(3)) to the immunized rabbit. These findings led to the conclusion that the thyroid-stimulating activity resided in soluble complexes of rabbit TSH bound to anti-bTSHbeta. Two of nine rabbits immunized with bTSH developed thyroid-stimulating activity in their serum, but it was nonsuppressible by T(3). None of the animals immunized with bTSHalpha, bLH, bLHbeta, or bLHalpha developed serum thyroid-stimulating activity.Hypopituitary hypothyroidism, evidenced by decreased serum thyroxine (T(4)) and thyroidal (131)I uptake and by the histologic appearance of large follicles with flat cells, was found in the bTSHbeta- and bTSH-immunized animals, despite the presence of thyroid-stimulating activity in the serum of many. The reasons for this paradox are unclear; possibly the complexes block the effect of TSH on the rabbit thyroid.

Animals↗