Search PubMed⌕ Search

Biomedical subjects

L Baldet

Publications and source records attributed to L Baldet.

At least 19 recordsLinked to original sources
PubMed1992

Thyroid hormone generalized resistance.

The syndromes of thyroid hormone resistance may affect overall or only some tissues. The generalized resistance is an inherited disease which involves a familial eumetabolic or hypometabolic goiter, increased free thyroid hormones with normal or elevated plasma TSH levels; children may present mental retardation, deafness, short stature and delayed bone age. The disease is frequently misdiagnosed. In vivo and in vitro tests may be used to assess the diagnosis. The defect of increment of sex hormone-binding globulin after administration of T3 may be useful in the demonstration of the disease. Therapy uses high T4 or T3 doses in hypometabolic patients. The generalized thyroid hormone resistance could be linked to abnormalities at the T3 receptor and c-erb A gene level, as a consequence of different point mutations or deletions involving the hormone-binding domain.

Drug Resistance↗
PubMed1992

[Endemic goiter in the La Kara region (Togo). Analysis of etiologic factors].

Among 6,035 people living in 3 villages from the area of La Kara (Togo), 984 randomized subjects were investigated to evaluate goiter prevalence and related etiologic factors. Creatinine and thiocyanates (SCN-) were measured in urine, thyroid hormones and TSH in plasma. Iodine was evaluated in urine, water, salt, soil, millet and sorgho. The amount of cassava was evaluated in food. Mean goiter prevalence was 32%, reaching to 45.9% in one village; urinary iodine remained in a low range (27.2 +/- 2.18 micrograms/g creatinine in adults, 34.3 +/- 6.7 in children--m +/- SEM) independently of the presence of endemic goiter. Urinary SCN- was increased. Low iodine values were found in food, salt, soil and water which contained few mineral elements except flour which was increased in the samples collected in one of the 3 villages. Cretinism was absent, T4, T3, TSH remained in a normal range. This study confirms a high prevalence of endemic goiter in the area of La Kara with iodine deficiency, leading to an urgent iodine supplementation.

Goiter, Endemic↗
PubMed1991

[Incidence of endemic goiter on Reunion Island. A search for etiological factors].

In an epidemiological study carried out in Reunion Island, 1,686 randomized school children aged from 11 to 15 years were examined for goitre by cervical palpation. A detailed questionnaire was fully completed by each child and his parents. The iodine level was measured in 168 urinary samples and in the salt and water consumed in the various places investigated. The overall incidence of goitre was 8.2 percent, rising up to 19.7 percent in the mountainous part of the island. The mean urinary iodine level was 40.2 +/- 2.7 micrograms I/g creatinine (m +/- SEM) and fell to 20.0 +/- 3.7 in the highlands. Water and salt contained little iodine. A significant relationship was noted between the presence of goitre on the one hand and sex, familial incidence of goitre, cassava consumption and distance from the coast on the other hand. This study demonstrates that endemic goitre and iodine deficiency are present in a limited area of Reunion Island.

Adolescent↗
PubMed1991

[Pathology of thyroid hormone receptors].

The syndrome of resistance to thyroid hormones may affect overall or only some tissues. The generalized resistance associates a familial eu or hypometabolic goiter, increased free thyroid hormones with normal or elevated plasma TSH levels. The inheritance of the disease is autosomal dominant in most of the patients. In vivo or in vitro tests may be used to assess the diagnosis. Therapy refers to high doses of T3 or T4. Pituitary resistance to thyroid hormones leads to hyperthyroidism with normal or high TSH levels. The treatment uses different TSH suppressive drugs. Peripheral resistance associates hypometabolism with normal T4-T3 secretion and needs high T3 doses for therapy. An inherited abnormality of T3 nuclear receptor seems to be the consequence of a mutant gene. Hypersensitivity to thyroid hormones associates hypermetabolism with low or normal free thyroid hormone levels and increased T3 nuclear receptors.

Drug Resistance↗
PubMed1990

A case of hypersensitivity to thyroid hormones with normally functioning thyroid gland and increased nuclear triiodothyronine receptors.

A 52-year-old male presented himself with tachycardia crises which appeared first during childhood, increased in frequency without goiter or exophthalmos. Cardiac and adrenergic diseases were excluded. The thyroid function was normal regarding T4, free T4 and T3, TBG, radioiodine uptake, TSH and T3 suppressibility; however the TSH response to TRH was decreased. The lymphocyte nuclear T3 receptor was found with an affinity close to that of normal volunteers (Ka: 1.42 x 10(10) M-1 vs 1.95 +/- 0.35 x 10(10) M-1) and a binding capacity markedly increased (9.9 vs 3.7 +/- 0.4 fmol T3/100 micrograms DNA). Pindolol was inefficient on the dysrhythmia which disappeared with carbimazole and relapsed after withdrawal of the antithyroid drug. Under carbimazole, the plasma T4 markedly decreased (27.7 +/- 3.6 nmol/l) but the patient remained euthyroid. The clinical course and the laboratory data suggest that the tachycardia crises are the consequence of a hypersensitivity of the heart to thyroid hormones, associated with an increased number of T3 nuclear receptor sites in lymphocytes.

Carbimazole↗
PubMed1989

The management of differentiated thyroid cancer in Europe in 1988. Results of an international survey.

In order to know how thyroid nodules and differentiated thyroid cancers are investigated and treated in 1988, an international inquiry was performed by mean of a questionnaire based on a well-defined case report of a 35-year-old female with a solitary small thyroid nodule. Clinicians were asked to indicate their diagnostic and therapeutic approaches to the reported case and to some variations. Analysis of the 157 responses from thyroid experts showed that three in vitro tests (sensitive-TSH, free T4 and total T4) and three in vivo tests (99mTc or radioiodide scintiscan, fine needle aspiration and ultrasonography) were performed most frequently. In the case of a solid and cold nodule and in the absence of fine needle aspiration results, 19% of respondents advocated suppressive therapy and 81% surgery. In the same clinical case, but whom fine needle aspiration had been performed and cytology was benign, surgery was advocated by 24%, suppressive therapy by 48% and a regular follow-up without treatment by 28% of respondents. When surgery was performed and the diagnosis was a differentiated thyroid cancer, (near) total thyroidectomy was more frequently chosen than partial thyroidectomy in both papillary (60 and 40%, respectively, of respondents) and follicular (74 and 26%, respectively, of respondents) cancers; 80% of clinicians did not change their surgical technique in relation to histological type of the tumour. Total thyroidectomy was more often recommended in most of the clinical or anatomical variations compared with the basic case report. Pre- or postoperative hormonal therapy was initiated with L-T4 and TSH suppression was controlled by sensitive-TSH and thyroglobulin determinations. After total thyroidectomy, 131I was used with similar modalities for papillary and follicular cancers to ablate a thyroid remnant.

Adult↗
PubMed1989

Novel immunoradiometric assay of thyroglobulin in serum with use of monoclonal antibodies selected for lack of cross-reactivity with autoantibodies.

A multisite immunoradiometric assay for measurement of serum thyroglobulin (Tg), designated Magnogel-IRMA-Tg, has been developed, involving magnetic microbeads (Magnogel). This assay is based on the use of five anti-Tg monoclonal antibodies (MAbs) directed against three antigenic regions on the Tg molecule that are not recognized by anti-Tg autoantibodies (aAbs). Four of these MAbs, directed against two antigenic domains, were coupled to the magnetic beads and were used to trap the serum antigen. Another MAb, directed against the third region, was iodinated and served as the labeled second antibody. The Magnogel-IRMA-Tg technique is reproducible, rapid, and sensitive (lower detection limit, 3 micrograms/L). The assay reliably measures serum Tg in the presence of anti-Tg aAbs.

Antibodies, Monoclonal↗
PubMed1989

Multi-center study of a new technique for measuring free thyroxin in serum.

In a multi-center trial we evaluated the accuracy of a new assay kit for free thyroxin (T4), the Behring free T4 RIAgnost, in 1036 subjects: 379 normal subjects, 536 patients with thyroid dysfunction, and 121 subjects with no thyroid dysfunction but with conditions that potentially could interfere with the assay. The kit combines immunoextraction and the use of a modified tracer. Although some limitations remained in using a direct assay method for free T4 in certain nonthyroid conditions, this test was superior to one based on the use of a T4 analog. This kit seems to be very accurate for the diagnosis of untreated thyroid pathologies.

Adolescent↗
PubMed1988

[Value of triiodothyroacetic acid as suppressive treatment of the thyrotropin secretion in thyroid pathology].

Fifty-six patients were treated with triiodothyroacetic acid (TRIAC) for its suppressive effect on the pituitary-thyroid function. Thirty of these patients had undergone partial thyroidectomy for benign goitre, and among these 14 had developed hyperplasia of the remaining thyroid tissue (group I); 18 presented with homogeneous or nodular goitre (group II); 8 had been thyroidectomized for carcinoma (group III). Before TRIAC was prescribed, thyroid hormones had been used in 33 patients, exerting a suppressive effect on the thyrotropic hormone in 4 patients of group III and producing signs of intolerance in 24 cases. TRIAC was administered in doses of 700-1,750 micrograms/day to all patients of group I and II, and combined with LT4 100 micrograms/day to group III patients. Suppression of the thyrotropic secretion was obtained in all group III patients and in 88 p. 100 of groups I and II patients. Thyroid gland hypertrophy regressed or disappeared in 21 patients of groups I and II, and no relapse or metastasis was observed in group III. TRIAC was well tolerated in all but one patients.

Adolescent↗
PubMed1987

[Study of discrepancies between "ultra-sensitive" TSH and thyroid hormones levels].

TSH levels were determined by "ultra-sensitive" assay (TSH-US) in 1300 sera and compared to thyroid hormone (TH = TT3 and FT4) values. Discordant results were observed in 186 cases divided into 3 groups according to TSH-US and TH values. Clinical data obtained in discordant cases showed that most of the subjects (75%) were under treatment (antithyroid drugs, suppressive or replacement hormone therapy) or had been treated by surgery or 131I when the sera were drawn. Among the patients who had not been treated (25%) we found moderate or subclinical hyperthyroidism (toxic adenoma or goitre) or hypothyroidism. In conclusion, most of the discordant results proved consonant when the clinical or therapeutic data were taken into account.

Humans↗
PubMed1987

Antigenic domains on the human thyroglobulin molecule recognized by autoantibodies in patients' sera and by natural autoantibodies isolated from the sera of healthy subjects.

We determined the regions on the human thyroglobulin (hTg) molecule recognized by anti-hTg autoantibodies (aAbs) in the sera of patients with Hashimoto's thyroiditis, Graves' disease, and thyroid carcinoma and by anti-hTg natural aAbs isolated from the sera of healthy subjects. Fifteen anti-hTg monoclonal antibodies (MAbs) directed against six distinct antigenic regions were used for this study. The anti-hTg aAbs in the patients' sera recognized mainly region II and occasionally region IV. The natural aAbs were present in the serum at low concentrations; consequently, we isolated and concentrated them for this investigation. The isolated natural aAbs inhibited the interaction of the anti-hTg MAbs with the majority of the antigenic regions identified. Region II was not well recognized, however, by these natural aAbs. This difference in specificity between the anti-hTg aAbs and the anti-hTg natural aAbs may have diagnostic significance.

Autoantibodies↗
PubMed1987

Are pituitary and thyroid function tests useful for the monitoring of antithyroid drug treatment and the post therapeutic control of Graves' disease?

The control of Graves' disease patients treated with antithyroid drugs (ATD) involves monitoring the dose of ATD, the duration of therapy and the prediction of the long-term outcome of the disease. The sequential follow-up of free thyroid hormones and ultrasensitive TSH (USTSH) helps in monitoring of ATD therapy, except in patients complemented with thyroid hormones. The normalization of early thyroid uptake of radioiodine or pertechnetate, which seems to be closely related to circulating thyroid-stimulating immunoglobulins, confirms the remission that leads to stopping ATD therapy. The raise of plasma USTSH in a normal range within the six months following ATD withdrawal is another indicator of remission. However, the post therapeutic course of Graves' patients remains unpredictable: late relapses and hypothyroidism may occur despite the normalization of the pituitary-thyroid axis, leading to a yearly clinical control with USTSH evaluation.

Antithyroid Agents↗
PubMed1987

Thyroid stimulating antibody: an index of thyroid stimulation in Graves' disease?

Early (20 min) thyroid radio-iodine uptake (ERU) and thyroid-stimulating antibodies (TSab) were determined in 27 untreated unselected patients with Graves' disease at the time of diagnosis. In 21 subjects the same tests were further performed in parallel during combined carbimazole-L-T3 therapy (mean duration of follow-up: 10.8 +/- 5.8 months; mean +/- SD). TSab was determined by a cAMP-human thyrocyte culture stimulation assay and expressed in microliter-equivalent of a TSab standard/ml (microliter-eq/ml). Before treatment, ERU, ranging from 15 to 54% of the injected dose (normal less than or equal to 8% dose) correlated with serum T3 (r: 0.54; P less than 0.01); TSab, ranging from 6 to 85 microliter-eq/ml was detected in 21/27 patients. There was a significant correlation between ERU and TSab (Spearman rank test: r: 0.57; P less than 0.01). During the first months of treatment, 5 of the 21 patients sequentially studied had undetectable TSab levels throughout the study and in these patients ERU decreased by 57% of its initial value; the remaining 16 subjects were divided into two groups according to ERU changes: in group A (9 patients), initial ERU decreased by 50% or more or the absolute value became less than 20% of the dose and TSab decreased from 10.9 +/- 4.8 microliter-eq/ml to 5.3 +/- 1.6 microliter-eq/ml (P less than 0.01); in group B (7 patients), the fall of ERU was less than 50% or the absolute value remained greater than 20% of the dose and TSab values remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1979

The TRG Test. Which is the best index of TSH release?.

Prolonged (two hours) TRH tests were performed on 29 controls and 182 thyrotoxicosis patients of varying thyroid status after treatment with radioiodine. The object was to find which of the simple measurements of TSH from the TRH test most faithfully reflected the total amount of TSH (TTSH) released in response to the TRH. The simple indices compared were the absolute levels of TSH (ATSH) achieved at intervals during the test, and the increments in TSH (delta TSH) recorded at the same points in time. TTSH was measured by planimetry of the area beneath the response curve. Patients were classified as normo-responders, hyper-responders or hypo-responders according to normal limits for TTSH deduced from the controls. When each simple index of TSH response was substituted in turn for TTSH, the overall frequency of misclassification was considerably greater for ATSH than for delta TSH. This was largely due to the wide variability of passive or basal TSH secretion, which seriously confused the distinction between normally-responsive and hypo-responsive patients when ATSH was used. The delta TSH measured at 30 minutes gave the best overall results in terms of least classification error and closest correlation with TTSH.

Adult↗
PubMed1978

[Hyperthyroidism].

Explore the source record for details and available documents.

Graves Disease↗
PubMed1978

[Chronologic study of free T3 and T4, of responses to TRH and of the suppression test during treatment of Basedow's disease].

32 patients with Graves' Disease were investigated before treatment, during ATD therapy and after recovery with a normal T3 suppression test. Before treatment, TRH response was negative with elevated values of plasma TT4, AFT4, TT3 and AFT3. The 3d, 6 - 9 and 12-18 months and after recovery, several patients remained unresponders to TRH despite normal AFT4 and AFT3 in serum. In an opposite way some patients were responders, 1 month after ATD withdrawal, at the 6-9 month, with elevated values of AFT4 or AFT3. The discrepancy between TRH response and T3 suppression test is pointed out after recovery. The unresponsiveness of TSH to TRH unexplained by serum AFT4 or AFT3 may be due to : 1) a decrease in pituitary TSH stores. 2) an unknown factor inhibiting TSH release during Graves' disease 3) an hypersensitivity of thyreotrop cells to T3.

Graves Disease↗
PubMed1978

[Interference of T4 in different serum T3 radioimmunologic determination kits].

The cross reactivity of T3 antibodies for T4 was studied with five T3 RIA kits. T4 used was provided from T4 RIA Kits (Abbot Beckman, Corning). The results are shown on the table indicating the concentration of T3 or T4 required to displace 50% of the T3 125 from anti T3. The cross reactivity for T4 of T3 antibodies from Lepetit and Phadebas was the same and was smaller than cross reactivity with the other laboratories. In clinical practice serum T4 levels of hypo and euthyroid subjects are not so high to false T3 determination. In hyperthyroid subjects the diagnosis cannot be influenced by this cross reactivity. However, the study of the kinetic and monodeiodination of T4 into T3 may be wrong when T4/T3 ratio increases.

Cross Reactions↗