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Biomedical subjects

E Baudin

Publications and source records attributed to E Baudin.

At least 55 records · Page 3Linked to original sources
PubMed1998

Pentagastrin testing in patients with renal insufficiency: normal responsivity of mature calcitonin.

Calcitonin (CT) is the most sensitive tumor marker for medullary thyroid carcinoma available, but it lacks specificity. Chronic renal failure (CRF) is known to be associated with elevations of serum immunoreactive calcitonin. Using an immunoradiometric assay to detect only mature CT, we evaluated the basal CT level and its response to pentagastrin in 30 patients with CRF and compared these data with those obtained in 71 controls. Basal mature CT was significantly higher (p < 0.05) in patients with CRF (3.55 pg/mL) than in controls (2.00). Among these patients, 20% had basal CT levels more than 10 pg/mL with a maximum of 51 pg/mL. Peak CT values (highest value obtained 3 or 5 minutes after pentagastrin) were comparable in the two groups. Among patients with CRF, 10% had peak CT values greater than 30 pg/mL with a maximum of 53 pg/mL. In this group of patients, no correlation was found between CT (at any time during the test) and parathyroid hormone, calcium, phosphate, or creatinine clearance. Men had significantly higher CT values compared with women at each time point tested, including peak values. Patients with CRF, who have not yet undergone dialysis, have moderately elevated basal CT levels, but have normal pentagastrin-stimulated peak CT levels.

Calcitonin↗
PubMed1998

Na+/I- symporter distribution in human thyroid tissues: an immunohistochemical study.

Antipeptide antibodies raised against the carboxyl-terminal region of the human sodium/iodide (Na+/I-) symporter (hNIS) were used to investigate by immunohistochemistry the presence and distribution of the hNIS protein in normal thyroid tissues, in some pathological nonneoplastic thyroid tissues, and in different histotypes of thyroid neoplasms. In normal thyroid tissue, staining of hNIS protein was heterogeneous and limited to a minority of follicular cells that were in close contact with capillary vessels. In positive cells, immunostaining was limited to the basolateral membrane. In contrast, in Graves' disease the majority of follicular cells expressed the hNIS protein. In autoimmune thyroiditis, the number of hNIS-positive cells, was similar to that found in normal tissue. These positive cells were found essentially close to lymphocytic infiltrates. This observation supports the concept of hNIS as an autoantigen. In diffuse nodular hyperplasia, hNIS staining was heterogeneous, but the number of hNIS-positive cells exceeded that found in normal tissue. In well differentiated follicular or papillary carcinoma, the number of hNIS-positive cells was significantly lower than in normal tissue. In poorly differentiated follicular carcinoma, the number ofhNIS-positive cells was less than that found in well differentiated carcinoma, or there were no positive cells. Interestingly, in all of these thyroid tissues, the number of follicular cells exhibiting TSH receptor (TSHR) immunoreactivity was greater than the number ofhNIS-positive cells. As hNIS expression appears to be related to TSHR stimulation, the decreased number of TSHR-positive cells in cancers may contribute to the reduced capacity of neoplastic cells to concentrate iodide. In one patient with a follicular cancer with an absence of hNIS immunostaining, the total body 131I scan showed no uptake in metastatic tissue. In three cancers with positive hNIS cells, the 131I scan showed uptake in lymph node metastases. This suggests that immunodetection of hNIS could predict radioiodine uptake in thyroid cancers.

Carrier Proteins↗
PubMed1998

Combination of radioiodine (131I) and probe-guided surgery for persistent or recurrent thyroid carcinoma.

To improve the completeness of surgical excision of persistent or recurrent differentiated thyroid carcinoma, the following protocol was used for the treatment of 54 patients with functioning lymph node metastases: administration of 3.7 gigabecquerels (100 mCi) 131I; total body scintigraphy (TBS) on day 4; surgery on day 5, using an intraoperative probe (Gammed 2, Eurorad); and postoperative TBS with the remaining 131I activity on day 7. The 54 patients (35 women and 19 men presenting 47 papillary carcinomas, 2 well differentiated follicular carcinomas, and 5 poorly differentiated follicular carcinomas) had already undergone surgery for differentiated thyroid carcinoma: total thyroidectomy (51 patients) or lobectomy with isthmusectomy (3 patients), with lymph node dissection in 33. One to 7 131I treatments were performed before inclusion. Preoperative 131I-TBS with a high dose of 131I allowed accurate localization of previously suspected neoplastic foci and detection of yet unknown foci in 56%; it was the most sensitive tool for localizing neoplastic foci. The use of an intraoperative probe was considered decisive in 20 patients, as neoplastic foci were found inside sclerosis due to previous surgery (n = 9), at unusual sites behind vessels or in the mediastinum (n = 10), or both (n = 1). In 26 patients, it facilitated the preoperative detection of foci with 131I uptake already depicted at preoperative 131I-TBS. In all 46 patients, the completeness of excision was demonstrated by both the probe and the postoperative 131I-TBS and was confirmed during follow-up. Of note, lymph node metastases undetected by 131I-TBS or by the probe were found in 14 patients at histological examination. This clearly shows that en block dissection is the only recommended procedure. In four patients, no neoplastic foci were found and in four patients, uptake was either due to the thymus (in two) or to the salivary glands (in two).

Adenocarcinoma, Follicular↗
PubMed1998

[Von Hippel-Lindau disease: recent genetic progress and patient management. Francophone Study Group of von Hippel-Lindau Disease (GEFVH)].

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder, predisposing to the development of central nervous system (CNS) and retinal hemangioblastomas, endolymphatic sac tumors, renal cell carcinoma and/or renal cysts, pheochromocytomas, pancreatic cysts and/or tumors. Incidence of the disease is 1/36,000. CNS hemangioblastomas and renal cell carcinoma are the main causes of death. The VHL gene, located on 3p25-26, is a tumor-suppressor gene which plays a major role in regulation of VEGF expression. Germline mutations of the VHL gene are identified in about 70-99% of the patients. Mutations associated with VHL type 2 (with pheochromocytoma) are mainly missense mutations with hot-spot at codon 167. Somatic mutations of the VHL gene are found in both sporadic central nervous system hemangioblastomas and sporadic renal cell carcinoma. For endocrinologists search for VHL disease (as for MEN) should be imperative in presence of a patient with pheochromocytoma and neuroendocrine pancreatic tumor.

Carcinoma, Renal Cell↗
PubMed1997

131I therapy for elevated thyroglobulin levels.

Assuming that the fractional uptake is the same, both after the administration of a diagnostic and a therapeutic activity, 131I uptake too low to be detected with 2-5 mCi may become detectable after the administration of 100 mCi. This should be performed routinely in patients with thyroglobulin levels above approximately 5 ng/mL during L-Thyroxine (LT4) treatment or 10 ng/mL off LT4 treatment for three main reasons: 1) in 80% of these patients, a post-therapy 131i total body scan showed foci of uptake in the neck or at distant sites, whereas in the other patients, metastases emerged clinically some years later; 2) 131I is not the only treatment modality, and, for instance, lymph node metastases may warrant further surgery; and 3) from a dosimetric point of view, the relevant parameter is the concentration of 131I, i.e., the ratio between the uptake and the mass of functioning tissue: a low uptake in a small metastasis may result in a higher 131I concentration than a higher uptake in a much larger metastasis.

Biomarkers, Tumor↗
PubMed1997

[Neuroendocrine tumors].

The term "neuroendocrine" designates tumors with common morphology and immuno-histochemistry characteristics whatever their localization or embryological origin. Diagnosis of neuroendocrine tumors implies: assay of markers and peptide hormones and scintigraphy examination (ostreoscan); family screening; treatment according to localization, degree of histological differentiation and extention as well as possible secretion of peptide hormones.

Antineoplastic Agents↗
PubMed1997

[Eutopic and ectopic production of glycoprotein hormones alpha and beta subunits].

Human chorionic gonadotropin (hCG) is a glycoprotein composed of two subunits, alpha and beta, linked together by a covalent bond. Ectopic production of hCG has been described in various histological types of cancer. Actually, these malignant tumors predominantly secrete the free beta subunit (hCG beta) and not hCG. Production of free hCG beta is especially found in patients with bladder, pancreas, uterine and lung tumors. In patients with neuroendocrine tumors, serum levels of free hCG beta are higher in gastrointestinal-pancreatic and lung tumors. The significance of ectopic production of hCG beta--epiphenomena or intrinsic biological role--remains unknown. Several reports on the similar structure of hCG beta and certain growth factors suggest that free hCG beta could have an effect on cell proliferation. Increased serum levels of the free alpha subunit are found mainly in patients with neuroendocrine tumors localized in the gut or lung. Serum levels may also be raised in patients with a pituitary tumor, but such production is often associated with a rise in other pituitary hormones. The free alpha subunit plays a role in embryon development and would stimulate production of prolactin by decidual cells. The free alpha subunit may also play a role in tumor growth.

Chorionic Gonadotropin, beta Subunit, Human↗
PubMed1996

[Differentiated thyroid epithelioma].

Long term prognosis of differentiated thyroid carcinoma is favourable, being modulated by several factors, age and histology being the most relevant. Initial treatment includes firstly surgery: loboisthmusectomy in case of intra-thyroid tumor, unifocal, less than 1.5 cm in diameter in patients with favourable prognostic indicators, total thyroidectomy with the administration of an ablative dose of 131l in all the other patients. A routine dissection of the paratracheal groove and of the supraclavicular area is performed in all patients. L-thyroxine treatment is given to all patients. Relapses should be discovered early; this is made possible by the combined use of serum thyroglobulin measurements and of 131l total body scans.

Carcinoma↗
PubMed1996

Octreotide scintigraphy in patients with differentiated thyroid carcinoma: contribution for patients with negative radioiodine scan.

Somatostatin receptor scintigraphy (SRS) was evaluated in 25 differentiated thyroid carcinoma (DTC) patients. All DTC patients had elevated thyroglobulin levels. A total body scan (TBS) was performed 4 and 24 h after injection of indium-111-DTPA-Phe-octreotide. Group 1 included 16 patients with negative 131I TBS; group 2 had 9 patients with positive 131I TBS. SRS results were compared to the results of conventional imaging methods in group 1 and to 131I TBS in group 2. 131I TBS was performed after administration of a therapeutic dose of 131I in all patients except one. SRS was positive in 20 of 25 (80%) patients. In group 1, SRS was positive in 12 of 16 patients; in the 3 patients with no previously known tumor site, SRS visualized one abnormal neck focus of uptake in two. In the other 13 patients, SRS disclosed unknown mediastinal foci in 2, but visualized less organ involvements and a smaller number of tumor sites than conventional imaging methods. In group 2, SRS was positive in 8 of 9 patients and visualized an identical (7 patients) or a smaller number (1 patient) of involved organs than 131I TBS; in 2 patients, SRS allowed the discovery of 1 abdominal and 1 bone tumor site. We suggest than SRS should guide imaging modalities in DTC patients with negative 131I TBS and be an alternative to 131I TBS in DTC patients unable to withdraw T4 treatment.

Adult↗
PubMed1996

Comparison of octreotide scintigraphy and conventional imaging in medullary thyroid carcinoma.

UNLABELLED: We evaluated the clinical utility of positive somatostatin receptor scintigraphy in patients with medullary thyroid cancer (MTC). METHODS: Twenty-four MTC patients with increased calcitonin levels underwent somatostatin receptor scintigraphy using 111In-pentetreotide (120-200 MBq) with early (4 hr after injection) and delayed (24 hr) whole-body scans and liver SPECT imaging. In Group 1 (12 patients), conventional imaging modalities demonstrated the presence of tumor sites prior to somatostatin receptor scintigraphy; in Group 2 (12 patients), conventional imaging modalities were negative or inconclusive. RESULTS: Somatostatin receptor scintigraphy had positive results in 9 of 24 patients (37%): of Group 1 patients, 7 of 12 had positive somatostatin receptor scintigraphy results. Of these patients cases, somatostatin receptor scintigraphy demonstrated several involved organs and tumor sites either identical (two patients) or smaller (five patients) in size than conventional imaging modalities. Only two patients in Group 2 had positive somatostatin receptor scintigraphy results which demonstrated significant mediastinal uptake previously classified as indeterminate on conventional imaging modalities. No new tumor site was identified nor were therapeutic options modified by the somatostatin receptor scintigraphy results. CONCLUSION: Somatostatin receptor scintigraphy only demonstrates part of tumor sites and cannot visualize small tumor sites (< or = 1 cm). We believe that somatostatin receptor scintigraphy has a limited role in the management of MTC patients.

Adult↗
PubMed1996

Iodine concentration by the thymus in thyroid carcinoma.

A 14-yr-old boy underwent a total thyroidectomy with bilateral neck dissection for a papillary carcinoma with lymph node metastases. Total-body scanning with 3.7 GBq 131I revealed radioiodine accumulation in the anterior mediastinum. CT and MRI demonstrated a mediastinal mass which corresponded to the area of increased radioactivity. Five months later, another therapeutic dose of 131I was followed by a sternotomy and removal of the thymus because a hand-held radiodetecting surgical probe demonstrated that the thymus was the mediastinal structure which concentrated iodine. Thymus histology was negative for thyroid cancer metastases (as further confirmed by the negative immunostaining) and showed cystic Hassall's bodies. Secondary ion mass spectrometry microscopy demonstrated that iodine was located only in the Hassall's bodies, bound to proteins. This finding suggests that an acquired "thyroid follicle-like" structure, as that observed in cystic Hassall's bodies, could be responsible for the epithelial cell iodine uptake. In conclusion, we have provided evidence for the iodine-trapping property of the cystic Hassall's bodies of the thymus, which may be a possible cause of misleading mediastinal radioiodine uptake.

Adolescent↗
PubMed1995

Abnormal calcitonin basal levels and pentagastrin response in patients with chronic renal failure on maintenance hemodialysis.

Hypercalcitoninemia has been reported in renal failure. Using a specific monomeric calcitonin (CT) immunoassay, we measured CT levels in 154 hemodialyzed patients. The relationship between CT and serum intact parathyroid hormone (PTH), gastrin, alkaline phosphatases, phosphate and calcium was studied. The pentagastrin test was performed in 26 patients exhibiting basal hypercalcitoninemia. Basal CT levels over 5.7 pmol/l (20 ng/l) were found in 25.3% of the patients and values higher than 26 pmol/l (90 ng/l) in 7.8%. Although CT is cleared by hemodialysis, post-dialysis CT levels either were unchanged or increased as compared with pre-dialysis values. This suggests that hypercalcitoninemia is not related to a decreased renal clearance, and that hemodialysis induces a specific regulatory pathway. None of the parameters studied were found to explain high CT levels. Of the patients with hypercalcitoninemia, 11.5% exhibited abnormal CT response to pentagastrin but no relationship between CT and phosphate, calcium and PTH levels was evidenced. Our findings confirm high CT monomer levels in renal failure. As there was no correlation with parameters classically involved in CT regulation, its physiological significance remains unclear. Abnormal CT response to pentagastrin raises the problem of its specificity as a tumoral marker with regard to medullary thyroid carcinoma.

Adolescent↗
PubMed1995

[Endocrine involvement in immunotherapy].

Thyroid dysfunction and abnormalities in corticosteroid regulation were observed after clinical use of cytokines (IL2, IFN alpha), molecules with immunostimulating properties. Interleukin 2 administration induces hypothyroidism often associated with anti-thyroglobulin and anti-thyroid microsomal antibody. All these features recall Hashimoto's thyroiditis. Frequency of thyroid dysfunction during immunotherapy varies according to authors between 20 and 40 percent of all patients treated. A correlation between thyroid dysfunction and response to IL2 therapy was reported. Hypothyroidism and hyperthyroidism with development of anti-TSH receptor antibody are observed after IFN alpha administration. An auto-immune aetiology of these thyroid side effects was suggested because fine needle aspirates of the thyroid of these patients, when available, revealed a mixed cellular infiltrate with lymphocytes and histiocytes and immunocytochemical staining showed strong HLA-DR expression of all thyrocytes. Involvement of lymphokine activated killer (LAK) or direct effect of cytokines on thyroid are also possible. After intravenous injection of IL2, a marked increase in ACTH levels occurred, peaking at 4 hour with a comparable peak in cortisol level at 5 hour. Expression of IL2-Receptor in pituitary cells suggests a direct action of IL2 on anterior pituitary. Nevertheless, indirect action of IL2 via induction of other cytokines or possible secretion of ACTH by activated lymphocytes, cannot be ruled out. Testosterone serum levels decreased significantly after IL2 or IFN alpha administration. It is noteworthy that these endocrine effects induced by cytokines may modulate the clinical efficacy of these substances underlying the bi-directional communication between the immune and endocrine system.

Adrenal Cortex Hormones↗
PubMed1995

Somatostatin receptor imaging: a preliminary experience in forty-nine patients.

We report our experience with the 111In-pentetreotide scanning of 47 adult patients presenting with neuroendocrine tumors (n = 38) or malignant pheochromocytomas or related tumors (n = 9), and 2 children with metastatic neuroblastomas. A dynamic study was performed after i.v. administration of 50-190 MBq of 111In-pentetreotide followed by a whole body scan at 1.5-4 hours and at 24 hours. Where indicated, tomoscintigraphy or a dual isotope bone, liver or kidney scan was performed in order to improve the anatomical definition. Lesions were visualized in the earliest phases of the examination but contrast was enhanced on delayed images due to an improved signal to background ratio. In 9/49 patients, octreotide scan (OS) detected unknown tumors sites. On the other hand, the lesion uptake of 111In-pentetreotide varied, and not all the sites shown by other imaging modalities were visualised, probably due to differences in membrane receptor expression. In conclusion, OS can be useful in the diagnosis, follow-up and therapeutic management of neuro-endocrine tumors. Further investigations are required to assess the role of OS in other pathologies. Short title: Somatostatin receptor imaging.

Adolescent↗
PubMed1994

[Elevation of lipoprotein(a) levels in patients following transplantation for ischemic cardiopathy].

OBJECTIVES: Increased levels of serum lipoprotein (a) in heart transplant patients has been recently shown to be related to early recurrence of coronary artery disease. In order to evaluate the effect of the ischaemic origin of the heart disease we compared lipoprotein (a) levels observed in heart transplant patients who underwent transplantation due to ischaemic heart disease and non-obstructive cardiomyopathy with those in healthy control subjects. METHODS: Serum levels lipoprotein (a) were measured in 62 cardiac transplantation recipients who had a hyperlipidemia. The results were compared with those of 212 control subjects matched for age and who were referred for hyperlipidemia. RESULTS: In the whole population 40 patients had been operated on for coronary heart disease and 22 for idiopathic cardiomyopathy. The two populations did not differ with regard to their cardiovascular risk factors except for the smoking status. The mean Lp(a) values were significantly higher in the subjects with coronary heart disease as compared with those with idiopathic cardiomyopathy (0.33 +/- 0.24 and 0.21 +/- 0.17 mg/dl respectively; p < 0.05). The latter were not different from the control group (0.22 +/- 0.19 mg/ml). We did not find any difference between the two populations concerning the drugs taken by the patients (especially cyclosporine), LDL-cholesterol, creatinine, fasting blood glucose and TSH. CONCLUSION: Our data confirm the relation between coronary atherosclerosis and high lipoprotein (a) levels.

Adult↗