Search PubMed⌕ Search

Biomedical subjects

D Guilloteau

Publications and source records attributed to D Guilloteau.

89 records · Page 5Linked to original sources
PubMed1987

Glycoprotein hormone alpha-chain-immunoreactive endocrine cells in prostate and cloacal-derived tissues.

All cloacal-derived tissues contain a similar endocrine cell population. Human chorionic gonadotropin (hCG)-like immunoreactivity has been reported in some prostatic endocrine cells. On the other hand, immunoreactivity to alpha-hCG is well known to occur in a variety of extraprostatic endocrine elements. Most cloacal-derived tissues were tested with a panel of monoclonal antibodies against hCG and subunits. The previously described hCG-like positivity was found to be exclusively related to the free alpha-subunit of hCG. Moreover, alpha-chain immunoreactivity was more broadly distributed in most cloacal-derived tissues, including those from the anal canal. In the anal canal, alpha-chain was an excellent marker of the anal transitional zone. alpha-Chain-immunoreactive endocrine cells were normal and nonneoplastic constituents of these tissues; they corresponded to a subpopulation of serotonin cells. In addition, certain prostatic argyrophil cell carcinomas might be exclusively alpha-subunit producing.

Calcitonin↗
PubMed1986

Calcitonin immunoreactive cells in prostate gland and cloacal derived tissues.

Calcitonin- and serotonin-storing cells have been immunocharacterized in prostate gland, urethra, urinary bladder and anal canal. In addition, a few hCG and somatostatin immunoreactive cells have been detected in prostate gland. All these cells were dispersed throughout the epithelial lining. In the anal canal, calcitonin cells were exclusively confined to the anal ducts and anal transitional zone epithelium. Calcitonin and serotonin cells were seen in some examples of prostatic adenocarcinoma. Combined techniques most often showed coexistence of calcitonin and serotonin immunoreactivities in the same endocrine cell. hCG immunoreactive cells corresponded to a subpopulation of serotonin-, calcitonin-storing cells. Calcitonin and serotonin cells were present in most organs which originated from the cloaca. In this territory, this distinctive endocrine pattern could be regarded as an excellent marker of cloacal derived tissues. These tissues constitute an additional site for extrathyroid C-cells. It is likely that calcitonin cells are a component of some prostatic adenocarcinomas.

Adenocarcinoma↗
PubMed1986

Calcitonin-secreting carcinomas of the prostate. An immunohistochemical and ultrastructural analysis.

Two cases of calcitonin-producing carcinomas of the prostate are reported. Light microscopical, immunohistochemical, and ultrastructural investigations have been performed. These tumors displayed a remarkable dual, endocrine and common epithelial (exocrine), differentiation. However, they presented two different architectural growth patterns. Of particular interest, numerous calcitonin cells were immunocharacterized. In addition, the endocrine component could harbour carcinoembryonic antigen, serotonin, human chorionic gonadotrophin, and prostate-specific acid phosphatase immunoreactive cells. Ultrastructural analysis confirmed the presence of numerous endocrine cells. These findings are not unexpected, since calcitonin, serotonin, and human chorionic gonadotrophin immunoreactive cells are normal and constitutive inhabitants of prostate gland. In the current cases, calcitonin cells showed a strong carcinoembryonic antigen immunoreactivity, as observed also in thyroidal C-cells. This peculiar kind of prostatic carcinoma might be compared to certain thyroidal tumors of intermediate type coupling parafollicular and follicular differentiation.

Acid Phosphatase↗
PubMed1986

[Iodo carboxamidino-1 phenyl-4 piperazine, a new adrenomedullary imaging agent: comparison with metaiodobenzylguanidine].

This report describes the comparison between two adrenal medulla imaging agents, mIBG and I-CPP. Biodistribution demonstrated an early and preferential uptake by both adrenal glands and heart and then storage in the adrenal gland of both agents, however I-CPP is less stable in vivo than mIBG. Reserpine depletion study in rat indicated that the I-CPP and mIBG uptake mechanisms are not similar.

3-Iodobenzylguanidine↗
PubMed1985

Medullary-thyroid-carcinoma imaging in an animal model: use of radiolabeled anticalcitonin F(ab')2 and meta-iodobenzylguanidine.

Radiolabeled anti-calcitonin (CT) immunoglobulin fragments (131I-anti-CT F(ab')2) and meta-iodobenzylguanidine (131I-mIBG) were injected into nude mice with a transplanted medullary thyroid carcinoma (MCT). 131I-Anti-CT F(ab')2 proved to be unsuitable for MCT scintigraphic imaging. However, a high mIBG uptake was observed in MCTs, but not in control tumors (mesothelioma). The uptake of mIBG was not modified by the presence of reserpine or pentagastrine. These results are discussed, and it is suggested that mIBG could be an APUD-system marker.

3-Iodobenzylguanidine↗
PubMed1984

[Sympathetic paraganglioma. Scintigraphic detection using a new labeled molecule, meta-iodobenzylguanidine].

Two cases of sympathetic paraganglioma are reported: one, benign, in a 20-years old woman with arterial hypertension and attacks of excessive sweating; the other, malignant and with bone metastases, in a 44-years old woman. Both were diagnosed by scintigraphy, using meta-iodobenzylguanidine as radionuclide. This new radiopharmaceutic agent has recently been introduced for the detection of phaeochromocytomas, but it seems to be a general tissue marker of catecholamine uptake and storage. Its use as a therapeutic compound may also be envisaged.

3-Iodobenzylguanidine↗
PubMed1984

Meta-iodobenzylguanidine adrenal medulla localization: autoradiographic and pharmacologic studies.

In order to investigate the mechanism of uptake of meta-iodobenzylguanidine (mIBG) by the adrenal glands, autoradiographic and pharmacologic studies were performed in mice and dogs receiving radioiodinated mIBG. In mice, on macroautoradiography of whole body sections 48 h after 125I-mIBG, most of the radioactivity was focused in the adrenal glands. On microautoradiography, silver grains were exclusively located in the adrenal medulla. Tissue counting after phenoxybenzamine, cocaine, and desipramine treatment resulted in 45%, 35%, and 0% inhibition of mIBG uptake, respectively. Tissue counting and scintigraphic studies demonstrated a more than 50% mIBG release from the adrenal glands after reserpine. These data indicate the high affinity of mIBG for adrenal medulla and suggest that the mIBG and catecholamine uptake mechanisms are only partially the same.

3-Iodobenzylguanidine↗
PubMed1984

[Imaging medullary cancer of the thyroid].

Based on experience of the last decade including 18 patients, the imaging procedures of medullary thyroïd carcinoma are reviewed. Ultrasonography of the neck is the most contributive for the locoregional expertise, in the preoperative period. All of the classical imaging procedures are useful in looking for the metastasis: namely bone scintiscan, liver ultrasonography, computerized tomography of the mediastinum. Associated parathyroid adenoma and pheochromocytoma are visualized respectively by technetium thallium subtraction scan and meta-iodobenzylguanidine scintigraphy. In the near future, immunoscintigraphy of calcitonin secreting tumors will be developed.

Adolescent↗
PubMed1984

[Plasma calcitonin and breast tumors].

In order to evaluate the frequency of elevated circulating calcitonin in patients with bone metastasis plasma calcitonin level was measured in 32 patients with breast carcinoma with and without bone metastasis. Calcitonin was found in normal ranges in all patients without metastasis. In patients with bone metastasis, 4 had normal level, 2 were found with elevated calcitonin. Our results suggest that elevated calcitonin is related to the presence of bone metastasis but is not a constant finding in these patients.

Adult↗
PubMed1983

Immunocytological study of the distribution of C-cells calcitonin in the thyroid gland of the normal adult gerbil.

The distribution of C-cells in the thyroid gland of the gerbil (Meriones inguiculatus) was studied on serial sections in the cranio-caudal direction. C-cells were visualized by immunofluorescence with an anti-calcitonin immune serum. A very heterogeneous distribution was found. C-cells first appear in the posterio-interior position. Then they progressively occupy the whole posterior part and finally are confined to the posterio-exterior position. No C-cells at all were detected in the upper and lower poles. According to the species, there is a wide variation in the relative distribution of C-cells in the thyroid gland. Our results add to the information available about the distribution of C-cells and its bearing on phylogenic evolution.

Animals↗
PubMed1981

Choroid plexus localization of 99mTc-pertechnetate.

Autoradiograms were performed on brain slices, 3 h after 99mTc-pertechnetate injection, and 24 h after previous treatment with stannous pyrophosphate. On macroautoradiograms, the radioactivity was focused entirely upon plexus areas. Silver grains were predominantly overlying the cytosol of brush border cells; less than 10% of the total plexus radioactivity was found in vascular structures. These findings suggest that a possible metabolic phenomenon exists rather than a passive distribution.

Animals↗
PubMedDate not supplied

[131I]metaiodobenzylguanidine treatment of a malignant paraganglioma.

The bone metastases of a malignant, non-secreting paraganglioma were treated with [131I]metaiodobenzylguanidine (131I-MIBG) over a 10-year period. Initial treatment (131I-MIBG: 9.6 GBq) resulted in a decrease in the number of bone metastases from 16 to 2. At three years, a relapse with primary tumor regrowth and liver metastasis was again treated with 131I-MIBG (22.2 GBq). A decrease in the number of bone metastases and MIBG uptake was again observed.

3-Iodobenzylguanidine↗
PubMedDate not supplied

[Comparison of plasma concentration and tolerance of a single dose of human calcitonin by intradermal and subcutaneous administration].

UNLABELLED: The aim of the study was to compare plasmatic levels of calcitonin obtained after intradermic (ID) and usual subcutaneous (SC) route of administration. PATIENTS METHOD: 6 volunteers between 18 and 40 years old received calcitonin 0.5 mg (Cibacalcin, Ciba-Geigy Laboratory) by ID and SC routes in a random order but at the same site of injection. Each administration was spaced by 8 days. Plasmatic levels were measured by R.I.A. before administration then 2 (M2), 7 (M7), 15 (M15), 30 (M30) minutes and 1 (H1), 2 (H2), 4 (H4), 8 (H8), 12 (H12) hours after each administration. RESULTS: Tmax were at 23.6 +/- 10 min and 16.2 +/- 7.5 min for SC and ID routes respectively. With ID route, Tmax was reached simultaneously or earlier (3 times). Cmax is significantly higher with ID route. Neither mean plasmatic levels at each plasmatic dosage nor mean areas under the curve between 0 to 1,440 min or between 0 to 480 min (this latest AUC calculate to minimize the importance of calcitonin basal level) were significantly different with ID and SC routes. 16 mild side effects (8 with each administration) were observed in 4 subjects. They appeared before 5 min. and were transient (1 hour) for cutaneous manifestations, and later between hours 3 and 7 for nausea and vomiting or asthenia. The mean lowering of calcemia was 0.29 +/- 0.21 and 0.18 +/- 0.11 mmol/l respectively for SC and ID route. In this study ID and SC routes for calcitonin administration are not different with regard to plasma levels and side effects.

Adolescent↗
PubMedDate not supplied

[Measurement of biological activity of hLH. Multicenter study].

This report describes the results of a multicentric study of biological methods for luteinizing hormone (hLH). The production of testosterone by animal Leydig cells is used by five laboratories with different methodologies including rat, mouse and pig cells. Dose-response curves of testosterone production, quality criteria and results on a physiological population of men and women, are reported and discussed. It is concluded that the bioactive determination of hLH must be considered as a reference method used in discordances between clinic and immunological methods.

Adult↗