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Biomedical subjects

J Bertherat

Publications and source records attributed to J Bertherat.

At least 37 records · Page 2Linked to original sources
PubMed2000

Hormonal and metabolic effects of radiotherapy in acromegaly: long-term results in 128 patients followed in a single center.

Conventional radiotherapy is usually indicated in acromegaly when surgery fails to normalize GH secretion. However, the benefits of radiotherapy are delayed. This has raised questions about the potency of this treatment for reaching the safe GH level of 2.5 microg/L and for normalizing insulin-like growth factor I (IGF-I) levels, both of which are currently recommended as the therapeutic goal. To evaluate the long-term hormonal and metabolic effects of radiotherapy in acromegaly, a retrospective analysis was undertaken studying 128 patients followed for 11.5+/-8.5 yr (mean +/- SD) in a single center. The preradiation GH levels decreased as a function of time to 50% at 2 yr, 20% at 5 yr, and 10% at 10 yr. Basal GH levels below 2.5 microg/L were obtained in 7% of the patients at 2 yr, 35% at 5 yr, 53% at 10 yr, and 66% at 15 yr. A basal GH level below 2.5 microg/L was associated with suppression of GH below 2 microg/L during an oral glucose tolerance test and normalization of IGF-I levels in 9 of 10 patients. Preradiation GH levels was the sole factor that could predict the delay in GH fall to below 2.5 microg/L (P = 0.008). At the last follow-up, IGF-I levels were normalized in 79% of the patients (37 of 47; mean follow-up, 15.0+/-11.3 yr). In the 32 patients presenting with diabetes mellitus, improvement of glucose tolerance was associated with lower GH levels after treatment (35+/-78 microg/L in the group of 13 patients still presenting diabetes; 9+/-12 microg/L in the group of 4 patients with glucose intolerance; 5+/-8 microg/L in the 14 patients with normal glucose tolerance; P = 0.04). Ten years after termination of radiotherapy gonadotroph, thyreotroph and corticotroph deficiencies were observed in 80%, 78%, and 82% of the patients, respectively. In conclusion, conventional radiotherapy can reduce GH levels below the optimal level of 2.5 microg/L and normalize IGF-I levels in acromegaly. However, the incidence of late hypopituitarism is high, and the delay to obtain this safe GH secretory status can be long, depending on the preradiation GH level. These parameters should be considered when adjuvant therapy is needed after surgery.

Acromegaly↗
PubMed2000

Outcome in patients with adrenal incidentaloma selected for surgery: an analysis of 88 cases investigated in a single clinical center.

OBJECTIVE: The study was designed to evaluate the clinical, endocrinological and radiological parameters used to investigate adrenal incidentalomas and select patients for surgery. DESIGN AND METHODS: An analysis of 88 consecutive patients with adrenal incidentaloma selected for surgery and investigated in a single clinical center was performed. RESULTS: Mean (+/-s.d.) age of the patients was 53+/-14 years. Fourteen (16%) of the adrenal incidentalomas were malignant tumors (2 adrenocortical carcinomas, 3 metastases, 4 adenocarcinomas, 4 sarcomas and 1 mesenchymoma), 10 (11%) were pheochromocytomas, 32 (36%) were non-secretory benign adrenal adenomas and the remaining were benign adrenal (n = 8; 9%) or extra-adrenal (n = 24; 27%) masses. Endocrinological investigations revealed 1 Conn adenoma, 4 tumors responsible for Cushing's syndrome or silent hypercortisolism and 1 androgen secreting tumor. Abnormalities of endocrine evaluations were observed in the 2 malignant adrenocortical carcinomas. Elevated 24-h urinary metanephrine levels were observed in the 9 pheochromocytomas tested. Complications of surgery occurred in 14% of the cases. Regardless of the endocrine status, parameters associated with malignant tumors were: older age (mean age of patients harboring malignant tumors vs patients with benign incidentalomas: 62+/-17 years vs 52+/-13 years, P = 0.005), weight loss (39% vs 7%, P = 0. 005), and mass diameter greater than 60mm (69% vs 15%, P < 0.001). By multiple logistic regression analysis malignant tumors were associated with increased age, diameter greater than 60mm and bilateral masses. CONCLUSION: This study points to a high rate of pheochromocytomas and malignant tumors in patients selected for surgery. This high rate differs from some previous reports and might be explained by the criteria used to select patients for surgery. Among these two groups of tumors, careful systematic endocrinological investigations allow the detection of altered secretion in the vast majority - if not all - malignant tumors of adrenal origin and pheochromocytomas. Only 5% of the incidentalomas below 30 mm selected for surgery in this study were malignant, in keeping with the use of this criteria as an important parameter to select patients with normal hormonal investigations for careful follow-up.

Adenoma↗
PubMed1998

[POEMS syndrome with primary adrenocortical insufficiency].

BACKGROUND: POEMS syndrome is a multisystem disorder. It usually presents as severe polyneuropathy and monoclonal gammapathy associated with endocrinopathies, organomegaly, skin hyperpigmentation. CASE REPORT: A patient with POEMS syndrome developed primary adrenocortical deficiency revelated by asthenia and hyperpigmentation. Hydrocortisone replacement therapy produced a rapidly beneficial effect on asthenia and hyperpigmentation. DISCUSSION: Although asthenia and skin pigmentation are common in POEMS syndrome, adrenocortical deficiency is seldom reported. This endocrinopathy might be underestimated in POEMS patients. We suggest systematic screening with a rapid ACTH test in all POEMS patients in order to detect underlying adrenal deficiency.

Adrenal Cortex Function Tests↗
PubMed1998

[Aberrant expression of the GIP (Gastric Inhibitory Polypeptide) receptor in an adrenal cortical adenoma responsible for a case of food-dependent Cushing's syndrome].

A 33 year old woman was investigated for an atypical case of Cushing's syndrome with suppressed early morning plasma cortisols. Chronic hypercortisolism was confirmed by classical biological criteria (24 h urinary cortisol excretion, dexamethasone suppression tests); more detailed dynamic and pharmacological tests revealed unanticipated features: spontaneous circadian plasma cortisol variations showed post prandial peaks; they could be induced by oral--but not intravenous--glucose tolerance tests, and were inhibited by the concomitant administration of Sandostatin (a somatostatin analog). Adrenal CT scan identified a 2 cm unilateral adenoma with ipsilateral and contralateral atrophy. Surgical removal of the tumor cured the hypercortisolism with hypocortisolism. Comparative analysis of the tumoral and normal tissues showed that only the former responded in vitro to GIP (Gastric Inhibitory Polypeptide) and contained the specific mRNA of the GIP receptor. This case illustrates a new pathophysiological mechanism of tumorigenesis due to the aberrant expression of a seven transmembrane domain receptor in a tumoral tissue. The nature of the given receptor induced a particular clinical phenotype related to food intake.

Adrenal Cortex Neoplasms↗
PubMed1997

[Differentiated thyroid carcinomas manifesting as toxic adenoma].

BACKGROUND: Hot thyroid nodules are generally benign. We report two exceptional cases of thyroid carcinomas mimicking toxic adenomas. CASE REPORTS: A 35-year-old man and a 55-year-old woman had thyroid carcinoma behaving as an autonomously hyperfunctioning nodule. DISCUSSION: Only twenty similar cases have been reported in the literature. While a hot nodule on radio-iodine scan is unlikely to be malignant, the possibility of carcinoma should not be overlooked. Surgery should therefore be the preferred treatment of toxic adenoma.

Adult↗
PubMed1997

Nuclear effects of the cAMP pathway activation in somatotrophs.

Activation of the cAMP pathway from the cell surface to the nucleus plays a major role in somatotroph differentiation and growth. This pathway is regulated mainly by the antagonistic hypothalamic hormones GHRH and somatostatin. Several pituitary-specific, as well as ubiquitous, expressed genes are regulated by cAMP in GH-secreting cells. Among them are the GH, GHF-1/Pit-1, c-fos and GHRH-receptor genes. Protein kinase A phosphorylation of Ser 133 of the transcription factor cAMP-responsive element binding protein (CREB), seems to play a pivotal role in the activation of the cAMP pathway in normal and tumoral somatotrophs. The oncogenic activating mutations of the G-protein as subunit stimulate transcription and CREB phosphorylation in somatotroph cells. The implications of the nuclear targets of cAMP in the differentiation and growth of somatotrophs are discussed in this review.

Cell Nucleus↗
PubMed1996

[Pituitary adenoma: mechanisms of endocrine oncogenesis].

Molecular studies on pituitary adenomas support a major role of molecular alterations in the pathogenesis of pituitary adenomas. Nevertheless, alterations in the neuro-hormonal control of the pituitary could also be involved in pituitary tumors formation. The finding that most pituitary adenomas are monoclonal has stimulated a search for somatic mutations. For instance, activating mutations of the Gs protein, leading to constitutive stimulation of the cAMP pathway, have been found in a subset of GH-secreting adenomas. But GHRH (growth hormone-releasing hormone) tumoral hypersecretion also stimulates the cAMP pathway and causes acromegaly. Pituitary tumor formation might result from accumulation of several alterations that would determine the tumoral phenotype. The majority of these alterations remains to be found.

Adenoma↗