Biomedical subjects
D Chevalier
Publications and source records attributed to D Chevalier.
[Cystadenolymphoma of the parotid gland. A study of 40 cases].
A statistical review of 40 cases of adenolymphoma (Whartin's tumor) of the parotid gland is presented. In 10% of the cases, other tumors are found in the same concerned gland. Therefore, the authors perform a subtotal parotidectomy rather than a simple removal of the tumor of a superficial parotidectomy. This policy reduces the risk of facial nerve injury by repeated dissection.
Vocal folds bilateral paralyses in closed position.
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[Severe laryngeal stenoses in adults. Results of the Réthi-Ward enlarging technic].
Treatment of severe cricoid stenosis with fixed vocal cords is difficult, the often used Réthi operation producing 20 to 30% of unsuccessful results. Use of a hyoid bone pedicle flap allows anterior enlargement with cricoid ring reconstruction, in addition to the classical posterior enlargement, and was successful in 8 of 9 cases treated by this method.
Interaction of plasma fibronectin (pFN) with membranous constituents of peritoneal exudate cells and pulmonary macrophages.
The prominent role of plasma fibronectin (pFN) in the host defense system as an opsonin for gelatin (collagen)-coated colloids has been established. In the present study we investigated the interaction of pFN and membrane isolates from cells devoid of collagen, as well as several tissues. In a liver slice assay system it was shown that subcellular membrane fractions from lung macrophages, peritoneal exudate cells, spleen, tests, and liver were able to competitively inhibit the pFN-mediated uptake of 125I-gelatin coated latex beads (gLtx) at low concentrations. Endocytosis of 125I-labeled membrane isolates by macrophage monolayers was also promoted by addition of pFN. In an attempt to characterize the membrane component(s) interacting with pFN, it was found that mild extraction procedure with 1 M KBr could release a significant amount of this inhibitory activity. Further studies demonstrated that the agent(s) responsible for inhibition of gLtx uptake was heat sensitive, not altered by trypsin treatment, and did not contain actin, a protein known to interact with pFN. This work indicates that pFN interacts specifically with an as yet unknown membrane component(s) and that such interaction will promote clearance of cellular debris by macrophages. This suggests that pFN may be an important opsonin for the reticuloendothelial system in clearance of collagenous and noncollagenous cellular debris once they are exposed to interact with it.
A new method for the simultaneous analysis of free and sulfoconjugated normetanephrine, metanephrine, and 3-methoxytyramine in human urine by HPLC with electrochemical detection.
A sensitive and specific assay for free and sulfoconjugated normetanephrine, metanephrine, and 3-methoxytyramine was achieved by tetraphenylboron complexing and by high-performance liquid chromatography with electrochemical detection. Sulfoconjugated metabolites were hydrolyzed by sulfatase. Complexing the 3-O-methylated catecholamines with tetraphenylboron followed by their extraction in either and reextraction in dilute hydrochloric acid succeeded in partially purifying the sample without the use of a prepacked column. Detection by electrochemical technique additionally eliminates unoxidable components in the urine. The relatively high sensitivity of this method permits measurement of metabolite concentrations as low as 10 ng/ml, allowing for the first time the determination of free 3-O-methylated catecholamines in human urine. Hydrolysis by sulfatase specifically identifies the form of the conjugated metabolite. The mean total (free plus sulfoconjugated) values of normetanephrine, metanephrine, and 3-methoxytyramine obtained from 25 normal volunteers were 214, 102, and 227 micrograms/day, respectively. Values were greatly increased in patients with pheochromocytoma. The degree of sulfoconjugation varied, and each individual metabolite was highest with normetanephrine (86%). This method is sensitive, rapid, simple, and can be easily standardized for clinical investigation of pheochromocytoma.
Community-based alternatives for discharge planning.
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Diagnosis of small and micro pituitary adenomas by intercavernous sinus venography. A preliminary report.
Intercavernous sinuses surround the pituitary gland and their form can be modified by small pituitary tumors. A preliminary report of the use of venography for the diagnosis of pituitary microadenomas is presented.
[Progress in the prevention of arrhythmia following myocardial infarction].
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[Use of bretylium tosylate in the prevention of the rhythm disorders of myocardial infarct].
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Simultaneous measurement of ERK, p38, and JNK MAP kinase cascades in vascular smooth muscle cells.
Activation of the mitogen-activated protein kinase (MAP kinase) pathways in cultured porcine aortic vascular smooth muscle cells (VSMCs) was determined following a 5-min stimulation with endothelin-1 (ET-1), phorbol 12-myristate 13-acetate (PMA), H2O2, or sodium arsenite. Extracellular signal-related kinase (ERK1/2), p38, and c-Jun N-terminal kinase (JNK1/2) MAP kinase activation was assessed using anti-phospho-MAPK kinase antibodies. The activation of these kinase cascades was also determined by resolving lysates on Mono Q using a fast protein liquid chromatography (FPLC) system and measuring the phosphorylation of specific substrates ERK1, c-Jun, and hsp27. The substrates were subsequently resolved from each other and the [gamma-32P]ATP in the reaction mixture by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and the incorporation of 32P was quantified by phosphor imaging. This technique revealed the presence of multiple peaks of activity phosphorylating ERK1 (5), c-Jun (7), and hsp27 (9). Differences in activation revealed by the chromatographic technique suggest that, although equivalent levels of activation may be detected by immunoblotting, the actual nature of the response differed depending upon the stimulus. Each stimulus that activated the MAP kinase cascades did not result in equivalent 'profile' of activation of kinase activities. These results suggest the presence of a mechanism of structural organization of the MAP kinase signaling molecules themselves resulting in the compartmentalization of responses with respect to the various cellular stimuli.
[Use of fast neutrons in the treatment of tumors of the salivary glands: rationale, review of the literature and experience in Orleans].
If low LET radiation therapy (photons, electrons), following radical microscopically and complete surgery can improve results in term of local control from 34 to 74% for salivary gland tumors, local control is more difficult to achieve in advanced tumors and only palliative treatment is usually attempted. In this survey, all the patient series treated worldwide were reviewed. They show an overall control rate of 31% with photon vs 64% with neutron therapy. A prospective randomised trial sponsored by the RTOG and the MRC published in 1988 and reviewed in 1993 showed an overall locoregional complete tumor clearance of 67% for neutrons and 17% for photons (P < 0.005), with 68% and 25% survival at two years for neutrons and photons respectively. This study was closed for ethical reasons. In Orleans, since 1987, 59 patients have been treated. At five years the persistent local control probability was 69.5%, the five-year crude survival probability 66% and the five-year tumor free survival probability was 64.5%. This review provides evidence that surgical treatment for salivary gland tumors should be limited to patients presenting a high likelihood of negative surgical margin and a small risk of facial nerve damage. Others patients should receive neutron radiation therapy alone as definitive treatment.
[Recurrent cerebral vascular complications connected with Methergine in obstetrics].
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