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Biomedical subjects

M Linquette

Publications and source records attributed to M Linquette.

At least 19 recordsLinked to original sources
PubMed1989

[New elements in the diagnosis and treatment of thyrotropic pituitary adenomas with hyperthyroidism].

Although thyrotropin-secreting pituitary tumors are rather exceptional, the authors have studied 5 new cases from 1982 to 1988. This apparently growing pattern is due to a more accurate diagnosis because of new laboratory measurements: --Immunoradiometric assay (IRMA) of ultra-sensitive thyrotropin (TSH); --Radioimmunoassay (RIA) of free alpha subunit of TSH; --Molar ratio of free alpha subunit/TSH before and after TRH stimulation; --Morphologic assessment of pituitary adenoma by computed tomographic scanning and nuclear magnetic resonance imaging; --Characterization of thyrotropin-secreting cells by immunohistochemical technics and identification of secretion products in cultured cells. The authors illustrate these new topics with a case report harboring a partial resistance to thyroid hormones. A 6-month treatment with somatostatin analogue (SMS 201.995) is reported, before transphenoidal ablation of the adenoma.

Adenoma↗
PubMed1987

[The syndrome of tissue resistance to thyroid hormones].

Known since 1967 and usually familial, the syndrome of tissue resistance to thyroid hormones may take one of two different forms, depending on the receptors involved. When resistance affects both peripheral and pituitary receptors, plasma thyroid hormone levels are high despite the lack of thyrotoxicosis, thyroxine and triiodothyronine are ineffective, even in high dosage, and plasma TSH increases to explode under TRH. When resistance only affects pituitary receptors, there is moderate thyrotoxicosis with paradoxical and inappropriate TSH increase. Contrary to expectations, nuclear receptors to triiodothyronine are perturbed in only a few cases. Reduction of thyrotropic hyperfunction, which is the primary purpose of treatment, can be achieved with D-forms of thyroid hormones or with somatostatin and its derivatives.

Humans↗
PubMed1979

[Comparative action of L-dopa and bromocriptine on thyreostimulating hormone (T.S.H.) in primary hypothyroïdism (author's transl)].

The comparative action of fixed I-dopa (500 mg orally) and bromocriptine (2,5 mg orally) doses on T.S.H. of 20 patients (8 men and 12 women) with primary hypothyroïdism was studied. T.S.H. was significantly decreased from first hour with I-dopa (p less than 0.005) and the greater decrease was reached at the second hour. T.S.H. was the thereafter progressively increased and was like basal value at the fifth or the sixth hour of the test. T.S.H. was likewise significantly decreased from first hour with bromocriptine (p less than 0,01), but the decrease was progressive during the six hours and the greater decrease was reached at the sixth hour (p less than 0,005). The decreased T.S.H. was greater for woman than for man as much with I-dopa (p less than 0,005), as with bromocriptine (p less than 0,002). The greater decrease was the same with I-dopa or bromocriptine. These results were comparatively discussed with others. They favoured an inibiting action of dopaminergic axis on T.S.H. secretion in primary hypothyroïdism.

Adult↗
PubMed1979

["Low triiodothyronine (T3) syndrome": "thyroxine (T4) euthyroidism" evidence (author's transl)].

As first described in serious systemic illnesses isolated decreased T3 plasma concentration was related to impaired peripheral conversion of T4, to T3 with preferential production of reverse T3 (rT3). A "low T3 syndrome" was seen in 47 out of 109 patients with extra-thyroidal diseases. Metabolic state, TSH and TSH responses to TRH were normal despite of low T3 concentration. Euthyroidism seems mainly due to T4 itself in these patients.

Aged↗
PubMed1979

[Pituitary adenomas with cells containing bêta MSH, alpha and bêta endorphins and without ACTH (author's transl)].

By using immunohistoenzymatic techniques, cells of 4 pituitary adenomas are revealed with beta MSH, alpha and beta endorphins antisera but do not react with 1--24 and 17--39 ACTH antisera. These data suggest that adenomatous cells are able to synthesize and LPH-like molecule without ACTH. The levels of plasmatic LPH and beta MSH, studied by RIA, stay normal. These results are discussed.

Adenoma↗
PubMed1979

[Wermer's syndrome (author's transl)].

The authors present a brief report on a familial case of Wermer's syndrome, and review the principal characteristics of this "multiple endocrine neoplasm" which usually affects the parathyroids, pancreas, and anterior pituitary.

Adult↗
PubMed1979

[Orthostatic hypotension in complicated diabetes mellitus: study of the renin-angiotensin-aldosterone system (author's transl)].

Plasma renin activity (P.R.A.) and plasma aldosterone (P.A.) were studied basally and after various stimuli in eight diabetic subjects with orthostatic hypotension and autonomic neuropathy. Five of them had chronic renal failure and proteinuria. On a diet containing 100 mEq Na/24 H, mean P.R.A. was 0,80 +/- 0,32 ng/ml/h in the supine position and 0,95 +/- 0,43 ng/ml/h in the upright position (N.S.); mean P.A. was 111 +/- 77 pg/ml in the supine position and 234 pg/ml in the upright position (p less than 0,01). On a diet containing 10 mEq Na/24 H, mean P.R.A. was 1,54 +/- 0,76 ng/ml/h in the supine position and 2,44 +/- 1,53 ng/ml/h in the upright position (N.S.). There was little stimulation of P. R. A. by low sodium intakes. After furosemide (n = 6), epinephrine + norepinephrine (n = 4) or diazoxide (n = 2), there was no stimulation of P.R.A. and P.A. Thus in diabetic patients with orthostatic hypotension and autonomic neuropathy basal values of P.R.A. and P.A. are in the normal range but there is dysregulation of renin-angiotensin-aldosterone system.

Adult↗
PubMed1978

Changes in pituitary gonadotropins during the amenorrhoea-galactorrhoea syndrome due to sulpiride.

Sulpiride, a dopamine receptor blocker which raises prolactin, was given to six women with idiopathic amenorrhoea for 10 days and to eleven women with regular cycles for 3 to 6 months. The latter group developed galactorrhoea and amenorrhoea during treatment. Basal LH AND FSH concentrations showed no significant changes. At 3 months but not at 10 days (amenorrhoea group) or 6 months (regular menses group) the area-under-the-curve of LH response to LHRH was increased. FSH responses to LHRH was not altered. The significance of these results to the hyperprolactinaemia-amenorrhoea syndromes are discussed.

Amenorrhea↗
PubMed1978

[Pituitary adenoma with alpha, 17-39 ACTH and beta, MSH cells, without hypercorticism (author's transl)].

In one case of pituitary basophil adenoma, the majority of the cells contains numerous small granulations which, by using immunohistoenzymatic technique, react with alpha, 17-39 ACTH and beta, MSH antisera. The reaction with anti beta, 1-24 ACTH is negative. The radioimmunoassay of ACTH reveals an increase of plasmatic ACTH, but the cortisol cycle stays low. This data suggests that this functional adenoma releases a product of which has an immunological relationship with ACTH, without biological activity.

Adenoma, Basophil↗