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Biomedical subjects

A Murat

Publications and source records attributed to A Murat.

At least 55 records · Page 3Linked to original sources
PubMed1997

Multiple endocrine neoplasia type 2: management of patients and subjects at risk. French Study Group on Calcitonin-Secreting Tumors (GETC).

Multiple endocrine neoplasia type 2 (MEN-2) is an inherited multiglandular disease with age-related penetrance and variable expression. The prognosis of MEN-2 is linked to the carcinological evolution of medullary thyroid cancer (MTC), which depends mainly on the stage of discovery, and to the incidents related to pheochromocytomas. The emphasizes the need for early diagnosis and management of MEN-2. Since 1993, mutations evidenced on the protooncogene RET have allowed subjects at risk to be identified, thus leading to a three-step management of these patients. (1) For all the potentially affected members of a MEN-2 family, screening by molecular genetics of the ret gene enables one to identify the subjects at risk who bear the mutation. When no mutation is observed, a linkage analysis study may be proposed. (2) In the subjects at risk, early screening for the various types of endocrine lesions may then start in childhood and be performed using specific biological markers of MTC, pheochromocytoma and primary hyperparathyroidism, and particularly, basal and pentagastrin-stimulated calcitonin measurement, which is known to be the most sensitive marker for the monitoring of MTC. (3) This step of biological investigations enables the earliest possible treatment of any endocrine lesion detected before it is expressed clinically, thus improving the prognosis of MEN-2. When genetic screening cannot be performed, only annual clinical and biological monitoring remain available in all members of a family affected with MEN-2.

Drosophila Proteins↗
PubMed1996

131I-6 beta-iodomethylnorcholesterol scintigraphy: an assessment of its role in the investigation of adrenocortical incidentalomas.

OBJECTIVE: Most incidentally discovered adrenal tumours ('incidentaloma') are benign adrenocortical adenomas. It has been suggested that 131I-6 beta-iodomethylnorcholesterol (IMC) scan could specify the degree of functional autonomy of such adenomas depending on whether they prevent contralateral adrenal tracer uptake. Our purpose was to examine this hypothesis in a correlated scintigraphic and endocrine study. DESIGN: Prospective study evaluating the prevalence of unilateral IMC uptake (tumour uptake with no visualization of the contralateral adrenal gland) and bilateral uptake (uptake in both the tumoral and the contralateral adrenal glands) in patients with unilateral incidentaloma. Comparison of adrenocortical function and of IMC scan after dexamethasone (DXM) in the two scintigraphic groups thus defined. PATIENTS: Thirty-five patients with a unilateral mass highly suggestive of benign adrenocortical adenoma on CT scan. MEASUREMENTS: The IMC scan was performed in basal conditions (baseline scan) and after DXM (suppression scan). Adrenocortical function assessment included basal measurements of 11-deoxycortisol, 17 alpha-hydroxyprogesterone (17-OHP), dehydroepiandrosterone sulphate (DHEAS), plasma cortisol and ACTH, urinary free cortisol (UFC), overnight and low-dose DXM suppression test, and CRH test. RESULTS: The baseline scan showed 16 patients (46%) with unilateral uptake (group A) and 19 (54%) with bilateral uptake (group B). Patients in group A exhibited lower ACTH values at 0800h (P = 0.05) and higher cortisol values after an overnight DXM suppression test (P = 0.02), than did patients in group B. In addition, 3 patients in group A failed the overnight and the low-dose DXM suppression tests. Adrenal masses were larger in group A than group B (P = 0.04) and an inverse correlation was found in the whole population between tumour size and ACTH value at 0800h (P = 0.05). On the suppression scan performed in 14 patients (7 in each group), patients in group A continued to exhibit unilateral tumour uptake and bilateral uptake was suppressed in 72% of patients in group B. An adrenal mass was removed in 3 patients of group A with confirmed benign adrenocortical adenomas. In the post-surgical period, the contralateral gland was again visualized in a baseline scan and the hormonal evaluation returned to the normal range. CONCLUSION: Unilateral 131I-6 beta-iodomethylnorcholesterol tumour uptake is a frequent feature in benign adrenocortical adenomas. Hormonal data and scintigraphic profiles obtained after dexamethasone, as well as hormonoscintigraphic changes observed after surgery, provide evidence that unilateral uptake is related to functioning adenomas with various degrees of autononomy and suggest that the 131I-6 beta-iodomethylnorcholesterol scan could be a valuable tool for screening 'subclinical' Cushing's adenomas.

Adenoma↗
PubMed1996

[Detection of residual lesions and metastases of medullary thyroid cancer].

Persistent hypercalcitoninemia represents a frequent situation particularly in case of inadequate surgery of medullary throid carcinoma (MTC). This event conducts to a surgical re-exploration after excluding the presence of distant metastases. After adequate initial surgical treatment the localisation of the residual or recurrent tumor tissue is often difficult with conventional imaging techniques. Immunoscintigraphy and selective venous sampling for calcitonin measurements have a good diagnostic sensitivity for cervical or mediastinal localisations and also for distant metastases. However complete remissions are not the rule after cervical and/or mediastinal reintervention which are proposed to patients who are free of distant metastases. This underlines the necessity of early diagnosis of MTC and adequate first neck operation.

Calcitonin↗
PubMed1996

[Pathologic study with immunohistochemistry of 61 pancreatic endocrine tumors in 16 patients suffering from multiple endocrine neoplasia type I (MEN I). Review of the literature].

The Multiple Endocrine Neoplasia (MEN I) or Wermer's syndrome is an uncommon disease which is most often inherited and affects mainly parathyroid glands, pancreatic islets and pituitary gland. The aim of this study concerning 61 pancreatic tumors in 16 patients suffering from MEN I was to define the macroscopic, histological and immunohistochemical characteristics of these tumors. The pancreatic endocrine tumors as part of the MEN I syndrome concern multiple tumors of small size, localized most often to the pancreas's tail. In 79% of cases, these tumors have a different predominating peptidic hormonal secretion in a same patient though most of them have plurihormonal secretions. The pancreatic polyendocrinopathy detection imposes a family investigation to look for a type I polyendocrinopathy.

Adolescent↗
PubMed1995

RET mutations in exons 13 and 14 of FMTC patients.

RET is a receptor tyrosine kinase gene which is responsible for three different inherited cancer syndromes namely multiple endocrine neoplasia type 2A (MEN 2A), type 2B (MEN 2B) and familial medullary thyroid carcinoma (FMTC) as well as for Hirschsprung disease (HSCR), a congenital disorder affecting the intestinal motility. Germ-line mutations in the RET exons 10 and 11 were demonstrated in the majority of the MEN 2A and FMTC patients. On the other hand, one codon of RET exon 16 is preferentially changed in MEN 2B patients. Recently, a germ-line mutation in the exon 13 was described in one FMTC family as well as in four sporadic MTCs. In the present study, we observed the same exon 13 mutation in two FMTC families. In addition, we identified a previously unreported substitution of RET exon 14 in two unrelated FMTC families. Both mutations segregate with the disease in these four FMTC families and involve the tyrosine kinase domain of RET. Haplotype analysis using polymorphic markers tightly linked to the RET gene indicates that in each pedigree the mutation arose as an independent event.

Adult↗
PubMed1995

Multiple endocrine neoplasia type 1 in France: clinical and genetic studies.

Multiple endocrine neoplasia type 1 (MEN1) is a hereditary syndrome characterized by the involvement of several endocrine glands, including the parathyroid glands, the pancreatic islet cells, the anterior pituitary gland and other neuroendocrine tissues. In order to build up a French MEN1 register, a collaborative network was developed through the 'Groupe d'Etude des Néoplasies Endocriniennes Multiples de type 1' or GENEM 1. A 2-year follow-up in 40 medical and surgical units allowed the identification of more than 150 individual patients and 45 MEN1 families, and defined the major clinical features of the disease in our series. Multiple endocrine neoplasia type 1 is inherited as an autosomal dominant trait. The gene causing this syndrome has been localized to chromosome 11, band 11q13, and molecular genetic markers flanking the MEN1 locus are of use in identifying disease gene carriers in predisposed families. Selected data were presented in order to discuss the management of patients by combined clinical, biochemical and genetic screening. The set-up of a national register by a multi-disciplinary and collaborative medical and surgical network will facilitate further research on the clinical management of MEN1 patients and the basic physio-pathology of the disease.

Adolescent↗
PubMed1994

Inter- and intrasubject variability of solid and liquid gastric emptying parameters. A scintigraphic study in healthy subjects and diabetic patients.

This study was performed to assess: (1) the inter- and intrasubject variability of gastric emptying measurements by a scintigraphic method in 12 healthy subjects and 14 diabetic patients, and (2) the reproducibility of diagnosis of either the presence or absence of gastroparesis. To address this issue, radiolabeled solid-liquid meals were ingested by all subjects on two separate days. High intersubject variability of gastric emptying measurements was shown in both populations. Intrasubject variability was higher in diabetic patients than in healthy subjects. However, there was no significant difference between the means of any parameters obtained on two separate days. The reproducibility of the diagnosis of gastroparesis was excellent for all parameters; the solid half emptying time was the most reproducible parameter (92% in healthy subjects and 93% in diabetic patients). The means +/- SD of the difference between the two separate days' half emptying time results were -10.6 +/- 41.3 min for solids and -4.8 +/- 36.6 min for liquids and were not statistically different from zero. Only one difference between the half emptying time results on two separate days was not in the 95% confidence interval for both solids and liquids; however, this result came from a diabetic patient with obvious gastroparesis on both days. Thus: (1) in spite of high inter- and intrasubject variability, the scintigraphic method of measuring gastric emptying is highly reproducible for the diagnosis of gastroparesis; (2) reproducibility is better in healthy subjects than in diabetic patients; and (3) the knowledge of intrasubject variability allows assessment of the required sample sizes for pharmacological studies using prokinetic medications.

Diabetes Mellitus, Type 1↗
PubMed1993

[The role of adrenal gland x-ray computed tomography and scintigraphy using radiolabelled norcholesterol in the etiological diagnosis of primary hyperaldosteronism].

The major etiologies of primary aldosteronism are aldosterone-producing adrenal adenoma, requiring a surgical treatment, and bilateral hyperplasia, usually managed with medical therapy. We only report a retrospective study on 22 patients with primary aldosteronism diagnosed by clinical and usual biochemical tests. All the patients were explored by computed tomography scan (CT) and iodomethyl-norcholesterol scintigraphy. The purpose of this study was to compare the capacity of the two methods to differentiate adrenal adenoma and hyperplasia. The CT scan was more sensitive (sensitivity: 88%) compare to scintigraphy (sensitivity: 64%) for the diagnosis of adrenal adenoma. However, the scintigraphy was a useful tool to detect asymmetric macronodular adrenal hyperplasia. Therefore, the catheterisation of adrenal venous would be only necessary for a few cases. We conclude from this study and the literature review that CT scan and iodomethyl-norcholesterol scintigraphy are complementary and both useful to increase diagnostic reliability of primary aldosteronism.

19-Iodocholesterol↗
PubMed1992

Magnesium, total calcium, phosphorus, copper, and zinc in plasma and erythrocytes of venous cord blood from infants of diabetic mothers: comparison with a reference group by logistic discriminant analysis.

Concentrations of magnesium (Mg), total calcium (Ca), phosphorus (P), copper (Cu), and zinc (Zn) were investigated in plasma (Pl) and erythrocytes (Erc) of venous cord blood of 44 infants of diabetic mothers (IDMs). These same concentrations plus total glycohemoglobin and fructosamine were determined at delivery in a subset of 15 mothers of these infants. Mineral results for IDMs were compared with those for 66 apparently healthy newborns. The duration of gestation in the two groups was significantly different (P < 0.001). After adjustment for gestational age, the mean (+/- SD) differences between groups were significant for birth weight, head circumference, Erc-Mg (1.71 +/- 0.17 for IDMs vs 1.76 +/- 0.15 mmol/L for control subjects), Pl-Ca (1.96 +/- 0.32 vs 2.48 +/- 0.22 mmol/L), Pl-P (1.99 +/- 0.40 vs 1.57 +/- 0.25 mmol/L), and Erc-Cu (10.9 +/- 2.41 vs 12.9 +/- 3.00 mumol/L), but not for Erc-Zn (33.0 +/- 18.3 vs 40.4 +/- 13.6 mumol/L). The variable that best discriminated between the two infant groups after adjustment for gestational age was Pl-Ca. In the 15 mothers, Pl-Mg (0.67 +/- 0.07 mmol/L) and Pl-Ca (1.66 +/- 0.21 mmol/L) concentrations were low, Pl-Zn (9.81 +/- 3.40 mumol/L) was normal, and Pl-Cu (33.5 +/- 10.7 mumol/L) was above normal. Correlations between total glycohemoglobin and mineral values of the mothers or paired IDM mineral values were not significant. The concentration of Pl-Ca was positively correlated with Erc-Cu (P < 0.001) and Pl-Cu (P < 0.05) in the comparison group newborns but not in the IDMs.

Calcium↗