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Biomedical subjects

R Volpé

Publications and source records attributed to R Volpé.

At least 109 records · Page 6Linked to original sources
PubMed1984

Graves' disease in pregnancy years after hypothyroidism with recurrent passive-transfer neonatal Graves' disease in offspring. Therapeutic considerations.

Symptoms and signs of severe hypothyroidism developed in a young woman at age 15. These symptoms progressed for a year; at age 16, she was found to have a firm goiter, thyroid autoantibodies, very low serum thyroxine and high thyrotropin values, indicating autoimmune thyroiditis with hypothyroidism. She received L-thyroxine, 0.20 mg per day, and was well until age 24 when she became pregnant. In the first trimester, manifestations indicative of hyperthyroidism developed; these were only ultimately recognized immediately after delivery of a 32-week still-born goitrous baby. Despite the discontinuation of thyroxine therapy, the hyperthyroidism persisted and was confirmed as Graves' disease by elevated thyroxine, triiodothyronine, and radioactive iodine uptake values, a diffuse scanning result, and the presence of thyroid-stimulating antibody. The patient was treated with propylthiouracil and became pregnant while receiving that regimen. Later, several months after delivery, the patient was treated with radioactive iodine, ultimately became hypothyroid, and has been treated ever since with thyroxine. She became pregnant again and, because of the continuing high titers of thyroid-stimulating antibody, received propylthiouracil, 100 mg daily, commencing in the third trimester of pregnancy, to avoid probable fetal hyperthyroidism due to the transplacental transfer of thyroid-stimulating antibody. In each of the last two pregnancies, when the infants were born, they seemed normal (because of the transplacental effect of propylthiouracil), but passive-transfer neonatal hyperthyroidism developed in each within 10 days after delivery, ultimately requiring treatment by conventional means. This case illustrates the following points: (1) Hyperthyroidism occasionally develops years after hypothyroidism. (2) In young women, high titers of thyroid-stimulating antibody may produce fetal and neonatal passive-transfer hyperthyroidism even at a time when the mother herself is no longer hyperthyroid; transplacental treatment of the fetus by maternal propylthiouracil ingestion may thus be necessary during the last trimester, but only when there is a high degree of probability that the fetus is at risk. (3) Because the infants had been protected in utero by the placental transfer of propylthiouracil, neonatal hyperthyroidism did not develop until several days after delivery.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1984

Human minimal androgen insensitivity with normal dihydrotestosterone-binding capacity in cultured genital skin fibroblasts: evidence for an androgen-selective qualitative abnormality of the receptor.

We have studied a kindred in which two parts of siblings, maternal first cousins, have a form of "minimal" androgen insensitivity that permits morphogenesis of unambiguous male external genitalia, but interferes with normal virilization at puberty. All four had gynecomastia that required reductive surgery. Apart from this common phenotype, they varied considerably in the temporal and regional aspects of their subvirilization and appreciably in their androgenic responsiveness to pharmacological doses of testosterone. The cultured genital skin fibroblasts from one set of siblings have an androgen-receptor activity with the following properties: (1) a normal maximum-binding capacity (Bmax) with 5 alpha-dihydrotestosterone (DHT), or the synthetic androgen, methyltrienolone (MT; R1881) as ligand; (2) a higher than normal apparent equilibrium dissociation constant (Kd) for DHT (0.77 nM) but not for MT; and (3) an elevated dissociation rate (k) of DHT-receptor (0.013 min-1, 37 degrees C), but not MT-receptor, complexes within intact cells. In addition, prolonged incubation with MT, but not DHT, augments the specific androgen-binding activity of the mutant cells as much as that of the controls. Normal cells yield lower values of apparent Kd for DHT (0.1-0.3 nM) after 2- than after 0.5-hr incubation (0.3-1.8 nM), and 1-hr values are intermediate. This occurs despite concurrent catabolic consumption of DHT from the medium and is considered to reflect transformation of initial, low-affinity DHT-receptor complexes to subsequent, higher-affinity states by a process that depends on time and initial ligand concentration. The mutant complexes described here can readily attain the highest state of affinity with MT, but have an impeded, variably expressed ability to do so with DHT. These findings suggest that a structural mutation at the X-linked locus that encodes the androgen-receptor protein is responsible for its androgen-selective dysfunction. Synthetic, nonhepatotoxic androgens, with corrective effects in vitro comparable to those of MT, may be therapeutically useful for these subjects.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1984

A micro reverse haemolytic plaque technique for the detection of antithyroglobulin antibody producing-lymphocytes in Hashimoto's thyroiditis.

Employing a micro reverse haemolytic plaque (RHP) technique, antithyroglobulin antibody producing B-lymphocytes have been detected in thyroglobulin challenged peripheral blood lymphocyte cultures from patients with Hashimoto's thyroiditis. The method employs a monolayer of sheep red blood cells instead of a semi-solid matrix as a medium for the development of plaques. This technique which requires very small amounts of immunoreagents, is therefore much less expensive than the macro methods. In our studies of patients with Hashimoto's thyroiditis, peripheral lymphocytes of patients produced a significantly greater number of plaques than lymphocytes from normal subjects on challenging with thyroglobulin. There was a good correlation between the thyroid antibodies detected by the haemagglutination tests in the sera of the patients and the production of plaques by their lymphocytes. The RHP assay also appeared to be more sensitive than the haemagglutination test. The technique should lend itself for the study of the effect of various lymphokines on cultured lymphocytes.

Antibody-Producing Cells↗
PubMed1984

Spontaneous secretion of thyroid autoantibodies by cultured peripheral blood lymphocytes from patients with Hashimoto's thyroiditis detected by micro-ELISA techniques.

The spontaneous in vitro production of anti-thyroglobulin (aTg) and anti-microsomal (aM) antibodies by mononuclear cells (MNC) from patients with Hashimoto's thyroiditis (HT) was analysed by an ELISA detection system. MNC from 35 HT patients spontaneously produced detectable levels of both autoantibodies in vitro (i.e., without mitogenic or antigenic stimulation). aTg was quantified using a reference aTg IgG standard and ranged from 55 to 9,000 ng aTg. Specificity of aTg by ELISA was assessed using heterologous Tg antigen (Ag). Microsomal Ag obtained by gel filtration was far less contaminated with Tg than the ultracentrifugation pellet. Specificity of aM ELISA was assessed using insulinoma membrane as unrelated Ag and by blocking aM detection only with microsomal Ag. aM levels in the 35 supernatants ranged from 0.1 to 1.12 OD. A direct correlation was found between aM serum titres detected by haemagglutination and in vitro aM spontaneous production, but not for aTg. This lack of correlation for aTg might have biological relevance. Tg restimulation in vitro enhanced aTg production in only four out of 18 cases, of which only one was significant. This system provides a tool for studies of the immunoregulation of thyroid autoantibody formation in vitro.

Antibody Specificity↗
PubMed1983

Graves' antibody.

Explore the source record for details and available documents.

Antibodies↗
PubMed1983

Evidence for cell-mediated immunity and specific suppressor T lymphocyte dysfunction in Graves' disease and diabetes mellitus.

Migration inhibition of purified peripheral T lymphocytes in response to pancreatic islet cell antigen or thyroid antigen was used to study cell-mediated immune mechanisms in patients with diabetes mellitus (IDDM) and Graves' disease (GD). In response to islet cell antigen, T lymphocytes of subjects with IDDM for less than 3 yr exhibited migration inhibition, whereas those of normal subjects, noninsulin dependent diabetics, and subjects with IDDM for longer than 3 yr did not. Admixture of T lymphocytes from normal subjects with T lymphocytes from patients with IDDM for less than 3 yr substantially ameliorated the migration inhibition of the IDDM subjects to islet cell antigen. Migration of T lymphocytes from GD subjects was markedly inhibited by thyroid antigen and marginally inhibited by islet cell antigen. Admixture of GD T lymphocytes significantly ameliorated the migration inhibition of IDDM T lymphocytes to islet cell antigen, despite sensitization to thyroid antigen of the GD T lymphocytes. We conclude: 1) sensitization to islet cell antigen in IDDM of recent onset is confirmed; 2) the ability of normal and GD T lymphocytes to ameliorate the migration inhibition of IDDM T lymphocytes strongly suggests correction of deficient suppressor T lymphocyte function; 3) the ability of GD T lymphocytes to ameliorate migration inhibition of IDDM T lymphocytes to islet cell antigen is evidence for an antigen-specific rather than a generalized suppressor T lymphocyte defect in GD; and 4) similarly, the normalization of migration index of GD T lymphocytes in response to thyroid antigen by those IDDM T lymphocytes not sensitized to thyroid antigen is again evidence for an antigen-specific and not a generalized suppressor T lymphocyte defect in IDDM.

Antigens↗
PubMed1981

Allosuppressor T lymphocytes abolish migration inhibition factor production in autoimmune thyroid disease: evidence from radiosensitivity experiments.

The ability of normal T lymphocytes to abolish the production of migration inhibition factor by antigen-sensitized T lymphocytes of Graves' disease (GD) and Hashimoto's thyroiditis (HT) in response to thyroid antigen has been studied by a modified migration inhibition factor test using isolated T lymphocytes alone. The production of migration inhibition factor was consistently abolished when normal T lymphocytes were mixed with GD or HT T lymphocytes in various ratios (1:9, 2:8, 5:5) as reported previously (Okita et al. 1980b). However, prior in-vitro irradiation (1000 rad) of the normal T lymphocytes resulted in loss of their ability to abolish migration inhibition factor production by the antigen-sensitized T lymphocytes of GD and HT. The effect is consistent with the radiosensitivity of suppressor T lymphocytes and indicates that the effect of normal T lymphocytes on GD and HT T lymphocytes is one of allosuppression. The results support the view that there is a defect in suppressor T cell function in GD and HT.

Antigens↗
PubMed1981

T-lymphocyte sensitization in Graves' and Hashimoto's diseases confirmed by an indirect migration inhibition factor test.

T-Lymphocyte sensitization in Graves' disease (GD) and Hashimoto's thyroiditis (HT) was studied by an indirect migration inhibition factor test using normal T-lymphocytes as second stage indicator cells. In the first stage, mononuclear cells or T-lymphocytes, fractionated by the standard Ficoll-Hypaque procedure from the blood of patients with untreated GD and HT, were cultured in Eagle's medium containing thyroid antigen, and their cell-free supernatants were saved. Normal T-lymphocytes as second stage indicator cells were packed in capillary tubes and placed in planchettes with the above supernatants to complete the indirect migration inhibition factor test. Inhibition of the migration of indicator T-lymphocytes was demonstrated when either GD or HT culture supernatants were employed. Moreover, there was a good correlation between the indirect using the culture supernatants and the direct migration inhibition factor test using mononuclear cells or T-lymphocytes. On the other hand, in both direct and indirect migration inhibition factor tests using mononuclear cells and mononuclear cell culture supernatants, respectively, in the presence of human liver antigen as a nonspecific antigen, there was no significant difference between controls and patients. From these results, we can conclude that GD and HT T-lymphocytes are sensitized to thyroid antigen and produce the lymphokine, migration inhibition factor, into the supernatant when exposed to this antigen.

Adult↗
PubMed1981

Suppressor T lymphocyte dysfunction in Graves' disease: role of the H-2 histamine receptor-bearing suppressor T lymphocytes.

The allo-suppressor effect of normal T lymphocytes on the production of migration inhibition factor by sensitized T lymphocytes of Graves' disease in response to human thyroid antigen has been studied further by a modified migration inhibition factor test employing purified T lymphocyte preparations. The production of migration inhibition factor was consistently abolished when normal T lymphocytes were mixed with the Graves' disease lymphocytes in various ratios (1:9, 2:8, and 5:5). However, pretreatment of the normal T lymphocytes with cimetidine (an H-2 histamine receptor antagonist) led to a demonstrable loss in their allo-suppressor properties, whereas pretreatment with chlorpheniramine (an H-1 histamine receptor antagonist) had no such effect. These studies indicate that a subset of normal T lymphocytes bearing H-2 histamine receptors suppresses the production or release of migration inhibition factor by sensitized T lymphocytes, and further suggest the possibility that there may be an abnormality in the H-2 receptors on Graves' disease suppressor T lymphocytes. It is conceivable that this defect is fundamental in the pathogenesis of Graves' disease.

Adult↗
PubMed1981

Immunological aspects of autoimmune thyroid disease.

There is considerable evidence to indicate that autoimmune thyroid diseases (both Graves disease and Hashimoto thyroiditis) are primary disorders of the lymphoid system. Evidence is now available to indicate that both cell-mediated and humoral immune factors are important in the pathophysiological expression of these conditions. The basic genetic defect in these disorders now appears to be the presence of a specific defect in suppressor T lymphocytes, which in turn permits the survival and expansion of a randomly appearing "forbidden" clone of thyroid-directed, organ-specific, helper T lymphocytes. These then cooperate with already present groups of appropriate B lymphocytes, which in turn produce humoral immunoglobulins directed against the thyroid. There appear to be subtle genetic differences that distinguish between Graves disease and Hashimoto thyroiditis, leading to their different expressions. Indeed, subtle genetic differences between different groups of patients with Graves disease may reveal whether there is a complete defect in immunoregulation (thus preventing any immunological remission) or a partial defect in immunoregulation, in which case the possibility of remission does exist. The role of stress in precipitating hyperthyroidism may be via stress-related physiological effects on partially defective suppressor T lymphocytes.

Antibody Formation↗
PubMed1981

Subacute thyroiditis.

The term "subacute thyroiditis" has come to be applied to two rather distinct forms of inflammation of the thyroid gland, both of which run courses lasting several weeks to several months. While it is clear that the term "subacute thyroiditis" connotes a temporal quality only, and could conceivably apply to any inflammatory process of intermediate severity and duration, by current usage it excludes several forms of infective (ie, bacterial fungal) thyroiditis. On the other hand, it specifically includes a painful form of thyroiditis of probable viral origin (de Quervain or pseudogranulomatous thyroiditis), and a painless form of thyroiditis, which may be called "subacute lymphocytic thyroiditis." The latter term does not necessarily imply that there is any relationship to chronic lymphocytic thyroiditis, as will be discussed carefully below.

Autoimmune Diseases↗