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Biomedical subjects

D Chevalier

Publications and source records attributed to D Chevalier.

At least 19 recordsLinked to original sources
PubMed2003

Comparison of remifentanil and alfentanil during anaesthesia for patients undergoing direct laryngoscopy without intubation.

BACKGROUND: Remifentanil and alfentanil are opioids often used during direct laryngoscopy (DL). This prospective, randomized study compared these agents with respect to haemodynamic and Bispectral Index (BIS) responses, glottic visualization, and rapidity of recovery (spontaneous ventilation, eye opening) in DL without intubation. METHODS: A total of 60 patients undergoing DL were randomized into two groups: remifentanil (R) and alfentanil (A). Anaesthesia was induced with propofol 2.5 mg kg(-1) and the opioid was administered 1 min later (R=2 microg kg(-1) or A=30 microg kg(-1) over 30 s). DL was commenced 1 min after (corresponding to 3 min after the beginning of induction). Glottic visualization, opioid and/or propofol re-injection, spontaneous ventilation recovery, and eye opening were recorded. RESULTS: During DL, mean arterial pressure (MAP) increased by 6% in the R group vs 20% in the A group (P<0.05) when compared with post-induction values without affecting heart rate or BIS. No significant difference was observed between groups with respect to glottic exposure, opioid and/or propofol re-injection, and spontaneous ventilation recovery (mean (SEM) 3.8 (0.6) min, R group vs 3.2 (0.7) min, A group, NS) or eye opening (7.1 (1.1) min, R group vs 7.4 (0.9) min, A group, NS). Thirty minutes after postanaesthesia care unit (PACU) admission, MAP returned to its pre-induction value in the R group (104 (3) vs 109 (3) at baseline, NS), whereas in the A group MAP remained significantly lower at this time point (96 (4) vs 106 (3) at baseline, P<0.05). CONCLUSION: This study showed that only remifentanil prevented MAP increase without adverse effects such as bradycardia during DL, and prevented MAP decrease 30 min after PACU admission.

Adult↗
PubMed2002

[Reconstruction after total circular pharyngolaryngectomy: comparison between gastric interposition and free jejunal flap].

AIM OF THE STUDY: To elucidate hospital mortality, morbidity and actuarial survival rates of patients with carcinoma of the hypopharynx and cervical oesophagus and to identify the technique of choice for reconstruction after pharyngolaryngectomy. PATIENTS AND METHODS: We reviewed the records of 209 patients who underwent total pharyngolaryngectomy between May 1982 and January 2000. The majority of patients had advanced cancer: hypopharyngeal in 131 cases and cervical oesophageal in 78 cases. Follow-up was complete for all patients. Chi 2 and log rank tests were used, with a limit of significance of 5%. RESULTS: The postoperative mortality and morbidity rates were 4.8% and 38.3%, respectively. Alimentary continuity was achieved using the stomach (127 patients), colon (5 patients), or free jejunal autograft (77 patients). The 1-year and 5-year survival rates were 62% and 24%, respectively. There was no significant difference with regard to the survival between gastric transposition and free jejunal autograft, but there were fewer complications in the gastric pull-up group with regard to the respiratory complications (33% vs 47.0%, p < 0.05), local recurrences (15.8% vs 33.8%, p = 0.004) and survival without dysphagia (76% vs 89%, p < 10(-5)). CONCLUSION: Surgical ablation is a viable option for advanced hypopharyngeal and cervical oesophageal neoplasms, and stomach interposition is the preferred method of reconstruction.

Actuarial Analysis↗
PubMed2002

[Oesophageal cancer in patients with head and neck cancers: therapeutic implications].

AIM OF THE STUDY: To determine therapeutic and prognostic implications of an associated head and neck primary cancer in patients undergoing oesophagectomy for squamous cell carcinoma of the oesophagus. PATIENTS AND METHODS: Between 1982 and 2000, 868 patients with oesophageal cancer were operated in our institution, including 78 (9%) who underwent oesophagectomy for associated oesophageal and head and neck cancers; the latter was synchronous (n = 52) or anterior metachronous (n = 26). Influence of head and neck cancer on the treatment of oesophageal carcinoma was analysed retrospectively in terms of surgical therapeutic strategy and survival. RESULTS: Oesophageal resection consisted of oeso-pharyngolaryngectomy (n = 14, 17.9%), subtotal oesophagectomy (n = 62, 79.5%) and cervical oesophagectomy (n = 2, 2.6%). Radical resection (R0) was obtained in 85% of cases. Postoperative mortality rate was 5 % (4/78). Main complications were pulmonary (18% = 14/78) and anastomotic leaks (14% = 11/78), all of them cervical. Follow-up (mean = 25 +/- 27 months) was complete for all 78 patients. Five-year survival after R0 resection was 25%. Survival pronostic factors were denutrition, complete resection, and pT status of oesophageal tumor. CONCLUSION: In patients with associated carcinomas of oesophagus and head and neck, agressive treatment -including an oesophagectomy- allowed a 5-year survival rate more than 25% without increased mortality or morbidity rates, compared with patients operated on for isolated oesophageal carcinoma.

Carcinoma, Squamous Cell↗
PubMed2002

[Cricoid chondronecrosis after prolonged endotracheal intubation].

Subglottic area injuries after prolonged endotracheal intubation are relatively frequent but cricoid cartilage necrosis is rare, with uncertain prognosis. Endoscopic findings are evocative even when clinical signs are not. When suspected, CT scan is required. The CT appearance is not specific, but the diagnosis can be strongly suggested in cases of fragmentation and collapse of the cricoid cartilage. We report two cases of cricoid chondronecrosis.

Adult↗
PubMed2002

[Endonasal plasmocytoma: diagnosis and management].

UNLABELLED: Plasmocytomas are either medullary (disseminated form) or extramedullary with or without bone infiltration (located form). Plasmocytoma is not a common tumor but extramedullary forms mostly occur in the upper respiratory tract without specific manifestations. OBJECTIVE: The aim of this study is to discuss the management (diagnostic and therapeutic) and the follow-up of extramedullary nasal plasmocytoma. MATERIAL AND METHODS: We report a case of a 71-year-old patient with unilateral nasal obstruction manifestation. RESULTS: Endonasal biopsy concluded plasma cell tumor without extension on CT scan. Treatment consisted of external nasal surgery and radiotherapy. CONCLUSION: Diagnosis of solitary extramedullary plasmocytoma can only be confirmed when the presence of systemic disease is excluded by performing clinical, biological (marrow bone biopsy) and radiological investigations. The treatment should be based on surgery with complementary radiotherapy if there is a skull base erosion. Long term follow-up is necessary because of the high risk of diffuse marrow involvement (multiple myeloma) which may occur after a long delay.

Aged↗
PubMed2001

Lymph node metastases from head and neck squamous cell carcinoma: MR imaging with ultrasmall superparamagnetic iron oxide particles (Sinerem MR) -- results of a phase-III multicenter clinical trial.

The aim of this study was to compare the clinical usefulness of ultrasmall superparamagnetic iron oxide (USPIO) MR contrast media (Sinerem, Guerbet Laboratories, Aulnay-sous-Bois, France) with precontrast MRI in the diagnosis of metastatic lymph nodes in patients with head and neck squamous cell carcinoma, using histology as gold standard. Eighty-one previously untreated patients were enrolled in a multicenter phase-III clinical trial. All patients had a noncontrast MR, a Sinerem MR, and surgery within a period of 15 days. The MR exams were analyzed both on site and by two independent radiologists (centralized readers). Correlation between histology and imaging was done per lymph node groups, and per individual lymph nodes when the short axis was > or = 10 mm. For individual lymph nodes, Sinerem MR showed a high sensitivity (> or = 88%) and specificity (> or = 77%). For lymph node groups, the sensitivity was > or = 59% and specificity > or = 81%. False-positive results were partially due to inflammatory nodes; false-negative results from the presence of undetected micrometastases. Errors of interpretation were also related to motion and/or susceptibility artifacts and problems of zone assignment. Sinerem MR had a negative predictive value (NPV) > or = 90% and a positive predictive value (PPV) > or = 51%. The specificity and PPV of Sinerem MR were better than those of precontrast MR. Precontrast MR showed an unexpectedly high sensitivity and NPV which were not increased with Sinerem MR. The potential contribution of Sinerem MR still remains limited by technical problems regarding motion and susceptibility artifacts and spatial resolution. It is also noteworthy that logistical problems, which could reduce the practical value of Sinerem MR, will be minimized in the future since Sinerem MR alone performed as good as the combination of precontrast and Sinerem MR.

Adult↗
PubMed2001

Surgical management of carcinoma of the hypopharynx and cervical esophagus: analysis of 209 cases.

BACKGROUND: Free jejunal transfer has become the standard technique for reconstruction of the pharynx and hypopharynx, especially with proximal neoplastic lesions, whereas gastric tube interposition is the technique of choice for reconstruction of the hypopharynx and cervical esophagus when resection extends below the thoracic inlet. HYPOTHESIS: Surgical ablation is a viable option for advanced hypopharyngeal and cervical esophageal neoplasms, with stomach interposition a safe and preferred method of reconstruction. DESIGN: Retrospective analysis. SETTING: University hospital that is a regional referral institution for esophageal cancer treatment and complex digestive reconstructions after esophagectomy. PATIENTS: We reviewed the records of 209 patients who underwent total pharyngolaryngectomy between May 1982 and July 1999. The majority of patients had advanced cancer: hypopharyngeal in 131 cases and cervical esophageal in 78 cases. INTERVENTIONS: Pharyngolaryngectomy and total esophagectomy with pharyngogastric anastomoses (n = 127); pharyngolaryngectomy, cervical esophagectomy, and reconstruction with free jejunal transplant (n = 77); and pharyngolaryngectomy and total esophagectomy with pharyngocolic anastomoses (n = 5). MAIN OUTCOME MEASURES: Postoperative mortality and morbidity, long-term survival, and prognostic factors influencing survival. RESULTS: The postoperative in-hospital mortality rate was 4.8% (10 patients), with a postoperative morbidity rate of 38.3%. Alimentary continuity was achieved using the stomach (127 patients), colon (5 patients), or free jejunal autograft (77 patients). The 1-year and 5-year survival rates were 62% and 24%, respectively. There was no significant difference with regard to the survival between gastric transposition and free jejunal autograft, but there were fewer complications in the gastric pull-up group (33% vs 47%, P<.05). The significant adverse factors affecting survival were tumor cervical localization, postoperative complications, disease stages pT3 and pT4 for the cervical esophageal tumors, microscopic pharyngeal penetration, or incomplete resection. The significant beneficial factors were tumor hypopharyngeal localization and postoperative radiotherapy. CONCLUSIONS: Surgical ablation is a viable option for advanced hypopharyngeal and cervical esophageal neoplasms, with stomach interposition the preferred method of reconstruction. Although the prognosis is poor, satisfactory short-term palliation can be achieved. The significant adverse factors affecting survival should be taken into account to select the candidates for surgery.

Adult↗
PubMed2001

Near total laryngectomy with epiglottic reconstruction. our experience of 65 cases.

From 1980 to 1998, 65 patients whose glottic lesions were classified T1 or T2 were operated with a reconstructive anterior frontal laryngectomy with epiglottoplasty such as described by Tucker (Arch Otolaryngol Head Neck Surg 115:1341-1344). This procedure consists of resection of the two vocal cords, in some cases one arytenoid, the anterior commissure with a part of the thyroid cartilage, the anterior part of both false vocal cords, and of 1 cm of the subglottis. The epiglottis is grasped downward to close the larynx. There were no per or postoperative deaths. Our functional results confirm those reported in the previous publications. The mean time of removal of the nasogastric tube was about 12 days and the patients were generally satisfied about their residual voice. Decannulation was performed after satisfactory peroral feeding, generally about 2 weeks postoperatively. Three patients only required subsequent procedures which can be considered due to functional failures. There were four recurrences, which means a 5-year actuarial local control rate of 94%. This operation takes place as part of our surgical treatment policy of laryngeal carcinomas, considering that this surgery is like an extensive frontolateral laryngectomy. In case of an infiltrating tumor or in case of invasion to the arytenoid cartilage, we perform a supracricoid partial laryngectomy with crico-hyoido-epiglottopexy (the Majer-Piquet's procedure).

Adult↗
PubMed2001

Characterization of new mutations in the coding sequence and 5'-untranslated region of the human prostacylcin synthase gene (CYP8A1).

Inheritable interindividual differences in prostacyclin production may be implicated in the pathogenesis of several human vascular diseases. Using a polymerase chain reaction/single-strand conformation polymorphism strategy, we screened for mutations in the gene encoding cytochrome P450 prostacyclin synthase (CYP8A1). DNA samples from healthy French volunteers (n = 130) of Caucasian origin were examined. Five mutations, comprising two previously reported silent mutations and three novel rare missense mutations (P38L, S118R, and R379S), were identified in the coding sequence of the gene. In the 5'-proximal region, we also found a variable number of tandem repeats (VNTR) polymorphism that consisted of four different alleles with 4-6 tandem repeats of a 9-bp unit containing a putative Spl transcriptional factor binding site. One of these (R6), a frequent allele (23.6% of alleles tested) harboring six repeats, is novel, whereas the other three are known. In vitro analysis of the effect of each VNTR allele on promoter activity of a reporter gene was performed by a transient transfection assay. Data confirmed the modulator effect of the VNTR polymorphism on reporter gene transcription. Furthermore, the data demonstrate that allele R6 has the most potent inducing effects in the A549 cell line and, after IL-6 stimulation, in human pulmonary artery endothelial cells. Overall, the data demonstrate that CYP8A1 is polymorphic in Caucasians, and that a polymorphism affecting the 5'-proximal region may result in interindividual differences in CYP8A1 transcriptional regulation in vivo. Additional factors, such as the presence of inflammatory mediators, may be required to modulate transcription of the CYP8A1 gene.

5' Untranslated Regions↗
PubMed2001

Identification of genetic variants in the human thromboxane synthase gene (CYP5A1).

Thromboxane synthase (CYP5A1) catalyzes the conversion of prostaglandin H2 to thromboxane A2, a potent mediator of platelet aggregation, vasoconstriction and bronchoconstriction. It has been implicated in the patho-physiological process of a variety of diseases, such as atherosclerosis, myocardial infarction, stroke and asthma. On the basis of the hypothesis that variations of the CYP5A1 gene may play an important role in human diseases, we performed a screening for variations in the human CYP5A1 gene sequence. We examined genomic DNA from 200 individuals, for mutations in the promoter region, the protein encoding sequences and the 3'-untranslated region of the CYP5A1. Eleven polymorphisms have been identified in the CYP5A1 gene including eight missense mutations R61H, D161E, N246S, L357V, Q417E, E450K, T451N and R466Q. This is the first report of genetic variants in the human CYP5A1 altering the protein sequence. The effect of these variants on the metabolic activity of CYP5A1 remains to be further evaluated.

Alleles↗
PubMed2001

Lingual thyroid. A case report.

We describe an unusual clinical case in which a non functional cervical thyroid coexisted with a functional ectopic lingual thyroid. A twenty-year-old woman was referred for hypothyroidism treated with L-thyroxin related to a basilingual tumor diagnosed 8 years previously. Oropharyngeal examination showed a spherical basilingual tumor 2.5 cm in diameter. Laboratory findings during treatment with 50 microgram of L-thyroxin daily showed: TSH 6,280 microIU/ml (N: 4,4 to 3.6), FT3 4,2 pmol/l (N: 3.3 to 5.1), and FT4 15.4 pmol/l (N: 10,5 to 25,5). Antithyroid antibodies were absent. Cervical ultrasonography showed a small hypoechogenic, heterogeneous orthotopic thyroid gland confirmed by cervical computed tomography thyroid. An I(123) scan revealed uptake above the chin on the profile, and no significant uptake is the area of the normal thyroid. The lack of iodine uptake by the cervical thyroid remains unexplained. In conclusion, this report of an ectopic thyroid location in unusual because of the coexistence of non functional cervical thyroid and of a partially functional lingual thyroid tissue. The pathogenesis of this association remains unclear.

Adult↗
PubMed2000

Two distinct forms of MAPKAP kinase-2 in adult cardiac ventricular myocytes.

Hsp27 kinase activities were studied in adult rat ventricular myocytes following sequential chromatography on Mono Q and Mono S. A basal level of activity was present following cell isolation. FPLC on Mono Q revealed three peaks of activity, peaks 'a', 'b', and 'c'. A fourth peak, 'd', was detected upon subsequent chromatography of the Mono Q flow-through on Mono S. Immunoblotting revealed that peaks 'a', 'b', and 'c' contained predominantly a 49 kDa form of MAPKAP kinase-2. Peak 'd' contained a 43 kDa form. 'In-gel' kinase assays using hsp27 indicated both forms of MAPKAP kinase-2 were active. No other bands of hsp27 kinase activity were detected. Both forms of hsp27 kinase immunoprecipitated with a MAPKAP kinase-2 antibody and have therefore been named MAPKAP kinase-2alpha (p49) and MAPKAP kinase-2beta (p43). MAPKAP kinase-2beta chromatographed on Superose 12 as a 60.7 kDa monomer whereas the behavior of MAPKAP kinase-2alpha suggested both a 65.7 kDa monomer and higher molecular mass complexes. Both activities phosphorylated hsp27 on serine residues, and two-dimensional phosphopeptide mapping indicated the same sites were phosphorylated. A tumor-promoting phorbol ester, phorbol 12-myristate 13-acetate (PMA), stimulated both MAPKAP kinase-2alpha and MAPKAP kinase-2beta activity. Inhibition of MEK activation with PD 98059 or p38alpha/beta MAP kinase activity with SB203580 blocked activation by PMA. However, whereas PD 98059 inhibited only the PMA-stimulated activation, SB203580 inhibited both PMA-stimulated and basal hsp27 phosphorylation. These data demonstrate the presence of two forms of MAPKAP kinase-2 in adult ventricular myocytes. Both forms are activated indirectly by the ERK MAP kinase pathway and directly by p38 MAP kinase but independently regulated.

Amino Acid Sequence↗
PubMed2000

Purification of myelin basic protein from bovine brain.

Myelin basic protein (MBP) is a commonly used substrate for in vitro determination of numerous protein kinase activities. Herein we describe a rapid method for isolating relatively large amounts of MBP from bovine brain with a purity greater than that currently available from commercial sources. Lipids were first extracted from the CNS tissue by homogenization in sec-butanol. Washes under neutral and mildly basic conditions were employed to remove neutral and acidic proteins from the defatted residue. MBP was subsequently extracted under acidic conditions and further purified by chromatography on CM Sephadex C-25. Potential contaminating enzyme activities were destroyed by heart treatment. This method typically yields a recovery of 1.0-1.5 mg MBP per gram of starting material with a purity of greater than 95%. The MBP prepared in this manner was suitable for determination of kinase activities by both solution and the "in gel" kinase assay systems.

Animals↗
PubMed2000

Endoscopic cordectomy. A proposal for a classification by the Working Committee, European Laryngological Society.

The European Laryngological Society is proposing a classification of different laryngeal endoscopic cordectomies in order to ensure better definitions of post-operative results. We chose to keep the word "cordectomy" even for partial resections because it is the term most often used in the surgical literature. The classification comprises eight types of cordectomies: a subepithelial cordectomy (type I), which is resection of the epithelium; a subligamental cordectomy (type II), which is a resection of the epithelium, Reinke's space and vocal ligament; transmuscular cordectomy (type III), which proceeds through the vocalis muscle; total cordectomy (type IV); extended cordectomy, which encompasses the contralateral vocal fold and the anterior commissure (type Va); extended cordectomy, which includes the arytenoid (type Vb); extended cordectomy, which encompasses the subglottis (type Vc); and extended cordectomy, which includes the ventricle (type Vd). Indications for performing those cordectomies may vary from surgeon to surgeon. The operations are classified according to the surgical approach used and the degree of resection in order to facilitate use of the classification in daily practice. Each surgical procedure ensures that a specimen is available for histopathological examination.

Glottis↗