Biomedical subjects

A Coste

Publications and source records attributed to A Coste.

At least 73 records · Page 4Linked to original sources

PubMed1996

Involvement of capsaicin-sensitive nerves in the regulation of glucose tolerance in diabetic rats.

The role of afferent sensory nerves in glucose tolerance and glucose stimulated insulin secretion was investigated in normal (N) or neonatal streptozotocin-induced diabetic (D) rats treated with capsaicin (NC and DC, respectively) during the neonatal period. In capsaicin treated animals, oral glucose tolerance was markedly improved both in NC and DC whereas insulin secretion was not affected. The effect of alpha 2-adrenergic blockade was investigated in D and DC rats. The alpha 2-adrenoceptor antagonist deriglidole (3 mg/kg i.p.) administered 30 min before glucose load slightly reduced glucose levels and markedly increased insulin levels both in D and DC rats. Thereafter, the high insulin levels were maintained or further increased following glucose administration. As a consequence, glucose tolerance was further improved in D and in DC, which already expressed an improved glucose tolerance after capsaicin administration. These results suggest that sensory nerves are implicated in the control of glucose tolerance in normal and neonatal streptozotocin-induced diabetic rats through a mechanism independent of insulin release. It is also suggested that afferent sensory nerves are not implicated in the adrenergic control of insulin secretion from pancreatic beta-cells.

Adrenergic alpha-2 Receptor Antagonists↗

PubMed1996

Epithelial cell proliferation in nasal polyps could be up-regulated by platelet-derived growth factor.

The modifications of epithelial differentiation and proliferation observed in nasal polyps (NP) could be related to local secretion of growth factors, among which platelet-derived growth factor (PDGF) could play a key role. We therefore prospectively studied, by immunohistochemistry, proliferating cell nuclear antigen (PCNA, an S-phase cell marker), PDGF, and CD-68 (activated macrophages marker) expression in NP and inferior turbinate mucosa (NM) in 11 patients. Our data show that PCNA and PDGF expression are increased in NP epithelium, while CD-68 expression is increased in NP epithelium and lamina propria when compared to NM. Increased local PDGF secretion by numerous activated macrophages could therefore be involved in epithelial cell proliferation up-regulation in NP. PDGF could also be involved in the pathogenesis of NP via its connective tissue remodeling actions.

Antigens, CD↗

PubMed1996

Airway epithelial damage induced by sulfur mustard in guinea pigs, effects of glucocorticoids.

Sulfur mustard (SM) represents a potential chemical warfare agent. In order to characterize SM-induced airway epithelial damage, we studied the effects of an intratracheal injection of 0.3 mg/kg of SM in guinea pigs, 5 h, 24 h, 14 days and 35 days after exposure. During the acute period, lesions prevailed in tracheal epithelium exhibiting intra-epithelial blisters, inflammatory cell infiltration and columnar cell shedding with exposure of basal cells. Fourteen days after intoxication, tracheal epithelium appeared disorganized and showed a significant decrease in height and cell density. Tracheal epithelium recovery was still not complete even 35 days after SM-intoxication. At day 14, in SM-intoxicated guinea pigs treated with betamethasone from day 7 to day 14, epithelium height, cell density and cell proliferation (evaluated by immunohistochemistry) were significantly increased compared to untreated guinea pigs. In conclusion, the lesions observed in SM-intoxicated guinea pigs seem to be in accordance with clinical human observations and are relevant to the study of airway epithelial damage induced by SM. This animal model could be used to illustrate tracheal epithelium regeneration mainly derived from basal cells and to show glucocorticoid effects on airway epithelial recovery after chemical aggression.

Animals↗

PubMed1996

Modified epithelial cell distribution in chronic airways inflammation.

Although airway epithelium is known to be modified during chronic respiratory diseases, epithelial cells have rarely been precisely quantified. We therefore intended to evaluate epithelial cell distribution in inflammatory airways, using a cytological approach. Nasal airway cells in 12 patients with nonallergic chronic rhinitis were sampled by brushing, quantified after cytocentrifugation and compared to those from eight controls. Cell populations were quantified after May-Grünwald Giemsa staining and alpha-tubulin immunolabelling to demonstrate ciliary differentiation. When compared to controls, rhinitis patients exhibited lower percentages of ciliated cells (59 +/- 4 versus 32 +/- 2%, respectively), and higher percentages of goblet (24 +/- 3 versus 37 +/- 2%) and basal cells (9 +/- 1 versus 18 +/- 2%). After tubulin immunolabelling, positive staining was specifically detected in cells with cilia (LC+), and in the cytoplasm of some small round cells without obvious cilia (LC-). Fewer immunolabelled cells were detected in rhinitis patients than in controls (with significantly lower percentages of LC+ and higher percentages of LC-). Nasal brushing is an effective technique for quantification of airway epithelial cells. Tubulin immunolabelling is useful to detect ciliated cells and distinguishes another cell population, possibly preciliated cells. These cytological findings suggest the presence of modifications of epithelial differentiation and proliferation, possibly related to local chronic inflammation.

Adult↗

PubMed1996

Sleep fragmentation as a risk factor for hypertension in middle-aged nonapneic snorers.

Although a high prevalence of hypertension has been observed in snorers, whether there is a direct link between hypertension and snoring remains controversial. It has recently been demonstrated that an abnormal amount of breathing effort during snoring is responsible for sleep fragmentation even in the absence of sleep apnea syndrome criteria. We hypothesized that sleep fragmentation during snoring may be a direct risk factor for the development of hypertension. On the basis of polysomnographic data, 105 nonapneic patients between 40 and 65 years of age referred for snoring with social impairment were selected and categorized as snorers with (n=55) or without sleep fragmentation (n=50) based on whether the arousals index was 10 or greater or less than 10/h of sleep, respectively. Sleep distribution did not differ between the two groups, except for a longer duration of wake after sleep onset (58 +/- 43 min vs 42 +/- 38 min) and a shorter duration of slow-wave sleep in the group with sleep fragmentation (72 +/- 34 min vs 97 +/- 34 min). Although there were no statistically significant differences between the snorers with and without sleep disruption in terms of age (51.3 +/- 7.7 vs 48.6 +/- 6.0 years), body mass index (26.9 +/- 4.0 vs 27.2 +/- 5.5 kg/m2), sex ratio, respiratory indexes during sleep, daytime sleepiness, and daytime tiredness, prevalence of systemic hypertension was significantly higher in the sleep-fragmented group (20/55 vs 7/50). This significant difference persisted (16/51 vs 6/49) when patients using antihypertensive drugs with possible effects on the CNS were excluded. Our data suggest that sleep fragmentation is common in patients who seek medical help for snoring with social impairment and may play a role in the development of hypertension.

Adrenergic beta-Antagonists↗

PubMed1996

Nasal polyposis pathogenesis: a flow cytometric and immunohistochemical study of epithelial cell proliferation.

In nasal polyps, constantly associated with chronic inflammation, frequent epithelial morphological changes (squamous metaplasia, secretory hyperplasia) suggest a dysregulation of epithelial cell proliferation. Cell proliferation in nasal respiratory epithelium was therefore evaluated in nasal polyposis. In 20 patients, we compared cell proliferation in mucosa from the inferior turbinate to these in nasal polyps using two methods: Flow cytometry analyzing first the ploidy and the percentage of S-phase cells (propidium iodide DNA labeling), secondly the percentage of Ki-67-labeled cells and the green fluorescent index (fluorescein-conjugated anti-human Ki-67 antigen labeling, and thirdly the percentage of Ki-67-labeled cells being in S-phase. Immunohistochemistry, quantifying the expression of Ki-67 antigen in the epithelium permitting to calculate a Ki-67 index. All cell-populations studied were diploid. Percentages of S-phase cells, Ki-67-labeled cells, Ki-67 labeled cells being in the S-phase and green fluorescence index was significantly higher in nasal polyps than in mucosa Ki-67 index were significantly higher in nasal polyps than in mucosa in the epithelium. Epithelial cell proliferation which is therefore increased in nasal polyp could play an important role in nasal polyposis pathogenesis and its relationships with inflammation can be suggested.

Cell Division↗

PubMed1996

[Comparison of concomitant radiotherapy and chemotherapy with radiotherapy alone in advanced cancers of the head and neck: results of a randomized trial].

From April 1987 to October 1992, 67 patients with inoperable squamous cell carcinoma of the head and neck region were included in a randomized trial. All patients had induction chemotherapy with cisplatin (100 mg/m2, D1) and fluorouracil (1 g/m2, from D1 to D5) every three weeks for a total of three cycles. Patients were randomized to concurrent external radiation therapy (70 Gy/39 fractions/8 weeks) and chemotherapy with cisplatin (50 mg/m2 in short infusion, D1, D15, D29, D43) and fluorouracil (5 mg/kg, intra-muscular, every Monday, Wednesday and Friday) (experimental group) versus radiotherapy alone with the same modalities (control group). The followup for living patients was 14 to 60 months with a median of 42 months. Analysis of preliminary results has shown that: 1) early and late side effects are similar in both groups; 2) after completion of treatment, the percentage of patients in complete remission was 71% (20/28) in the experimental group and 43% (12/28) in the control group; this difference was statistically significant among non responders to induction chemotherapy (1/15 versus 13/20, P = 0.001), but non significant among responders (11/13 versus 7/8) and 3) there were no differences between both randomized groups in term of 3-year overall survival and of 3-year loco-regional control. Results are discussed taking into account a review of literature.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1996

[Osteoma of the naso-sinusal cavities. Surgical indications and role of endonasal endoscopic surgery].

Osteoma of the para-nasal sinuses is a rare and benign tumor that develops slowly. When therapy becomes mandatory, it is necessarily surgical and requires a standard external approach. This report analyses seven cases of operated osteomas, using different surgical techniques, adapted to different indications. Three patients underwent exclusive endonasal endoscopic surgery, and four patients had external surgery coupled with endonasal surgery. Results have proven successful with a four-year median follow-up. Epidemiological, clinical, histological and therapeutic considerations as well as the value of the endoscopic endonasal surgical approach are discussed. Endonasal endoscopic surgery can be used alone in naso-ethmoidal osteomas. It must, though, be associated with external standard procedure when the osteoma involves important extension to the frontal sinuses. In isolated frontal osteomas, external standard approach is mandatory for resection, endonasal technique being in this case contributive to the repermeabilisation of the infundibulum.

Adult↗

PubMed1996

[Treatment of antro-choanal polyp by enlarged endoscopic meatotomy. Apropos of 19 cases].

Antro-choanal polyp (ACP) is traditionally removed by performing Caldwell-Luc operation. The aim of this study was to evaluate the interest of removing ACP via enlarged middle meatotomy performed under endoscopic control (EMM). The cases of 19 patients who underwent EMM for ACP removal between 1991 and 1993 were retrospectively analyzed. The main symptom was nasal obstruction and ACP was diagnosed according to endoscopy, CT-scan and pathological examination. The usual technique for EMM included coagulation of the mucosal area of implantation of the ACP pedicle. The pedicle was localized on the external maxillary wall in 68.5% of cases. No complications was reported while ACP recurred in only one case. Using EMM to remove ACP appears therefore to be a safe and non-invasive method. The localization and removal of the ACP pedicle with coagulation of its mucosal area of implantation is recommended.

Adolescent↗

PubMed1995

Alpha 2-adrenoceptors and the regulation of glucose, insulin and amylin levels in diabetic rats.

The effects of the selective alpha 2-adrenoceptor agonist UK 14.304 on glucose, insulin and amylin levels were examined in neonatal streptozotocin-induced diabetic rats. UK 14.304 (0.03 to 0.3 mg/kg i.p.) induced a dose-dependent reduction of both insulin and amylin levels in normal rats while UK 14.304 at 0.03 mg/kg had already a maximal effect in diabetic rats. Amylin/insulin molar ratios rose after UK 14.304 administration in diabetic rats but remainded constant in normal rats. The alpha 2-adrenoceptor antagonist deriglidole (3 mg/kg i.p.) slightly increased insulin and amylin levels in the two groups of rats but glucose levels were more markedly decreased in diabetic rats. Deriglidole completely antagonized UK 14.304 (0.1 mg/kg i.p.)-induced changes thereby normalizing amylin/insulin molar ratios in diabetic rats. These results suggest that insulin and amylin are both under inhibitory control via alpha 2-adrenoceptor though the responses may be differentially regulated. It is further suggested that diabetes in the neonatal streptozotocin-induced rat model is associated with a hypersensitivity of the pancreas to alpha 2-adrenoceptor stimulation.

Amyloid↗

PubMed1995

Endoscopic and CT-scan evaluation of rhinosinusitis in cystic fibrosis.

In order to obtain an accurate evaluation of nasal and paranasal sinus disease in cystic fibrosis patients, 75 patients with a proven cystic fibrosis diagnosis have been investigated using the following standard techniques: questionnaire, ENT examination, endoscopical examination, sinus X-rays, and in 31% of the cases a CT scan. The analysis of results shows that nasal obstruction is the most frequent symptom (32%) and that nasal polyps are present in 43% of the cases. Endoscopic examination seems to be of great interest in giving a more accurate picture of nasal and paranasal sinus disease. Analysis of CT scan images leads the authors to describe a new and specific entity in nasal and paranasal sinus disease in cystic fibrosis patients: the pseudomucocele. In this report, the authors discuss the various aspects of pseudomucocele, attaching particular importance to the CT scan results.

Adolescent↗

PubMed1994

[Current aspects of laryngeal tuberculosis. Apropos of 4 cases and review of the literature].

After the discovery of streptomycin 1944, laryngeal tuberculosis became a rare complication of advanced pulmonary tuberculosis. Since that time the clinical aspects of the disease have changed. We analyzed these changes by reviewing 65 papers in English and in French published from 1965 to 1991 involving 738 cases and added our 4 new personal cases. To our knowledge, we report the first two well-documented cases of laryngeal tuberculosis in HIV positive patients. We propose a therapeutic and follow-up protocol for laryngeal and chest specialists treating such patients.

Adult↗

PubMed1994

[Contribution of x-ray computed tomography in the diagnosis of cervical suppuration].

The authors report their experience with computed tomography (CT) in 27 cases of cervical suppurations. The diagnosis was confirmed surgically in 24 cases and by the improvement of clinical signs and CT after antibiotics in 3. Two types of CT features were identified: collected abscesses (n = 22) visualized as encapsulated heterogeneous hypodense formations and extensive suppurative cellulitis (n = 5) formed by large diffuse hypodense collections without a clearly visible peripheral wall. The extension of the suppurative process could be evaluated precisely with CT, especially in certain anatomic areas where physical examination is difficult including mediastinal suppurations (n = 2), extension of parapharyngeal suppurations to the retrostyleal area (n = 1), and pterygo-maxillary and epidural collections (1 each) the latter in combination with a tuberculous abscess. Computed tomography is also useful in the etiological diagnosis (search for foreign body, cystic malformations, tuberculosis) and in post-treatment follow-up to visualize the absence of collections after cure in cases of favourable outcome and to determine the extent of the suppurative process in case of complications.

Adult↗

PubMed1994

[Functional endoscopic surgery of sinusal mucocele].

The treatment of paranasal sinus mucoceles must assure complete removal and prevention of recurrence. In order to clarify the precise indications for endoscopic management, a retrospective study was undertaken on 16 patients with paranasal sinus mucoceles treated by this method. All of the patients underwent endoscopic exploration with or without an associated bicoronal approach. The follow-up period varied between 3 months and 46 months with a mean of 24. The results were considered satisfactory if the patient's symptoms disappeared and follow-up endoscopy revealed persistence of sinus permeability. Functional endoscopic surgery can be considered as an alternative method in treatment of sinus mucoceles. Only mucoceles confined to the lateral wall of the frontal sinus, and the extended mucoceles, seem to be an out of the way place to endoscopic sinus surgery alone. In these cases, the access has to be completed by an external approach. Concerning adequate recanalization of the nasofrontal duct, results seem encouraging, however a long-term follow-up is necessary to obtain an accurate assessment of the results.

Adult↗

PubMed1994

[Tympanoplasty using chondro-perichondral graft. Indications, techniques and results. Apropos of a series of 127 cases].

In an attempt to avoid recurrence, the authors have used chondro-perichondral grafts for more than 10 years for tympanoplasty of retraction pouches. Early results were published in 1987. This new retrospective series of 127 tympanoplasties, performed from 1987 to 1991 reports the anatomic and functional results obtained and the technical modalities used. After a mean follow-up of 18 months, the results appear encouraging. Indications of this chondro-perichondral graft have been widened to cases of unsuccessful first intention myringoplasty and to certain cases of progressive perforations occurring in a setting of inflammation or tubal dysfunction. The results must be confirmed on the basis of long term outcomes.

Adolescent↗

PubMed1994

[Value of imaging in sphenoidal pathology. Role of magnetic resonance].

The authors use case studies to illustrate the respective benefits of CT and MR imaging in the management of sphenoid sinus disease. Because the sphenoid sinus is located deep in the skull base adjacent to vital neurological and vascular structures, surgery involves a certain risk. The improved quality of imaging now available provides essential information on which to base therapeutic options. Since CT and MR findings make it possible to increase the precision of the pretherapeutic evaluation and to determine neurological and vascular involvement, these imaging studies have become an integral part of the successful management of sphenoid sinus disease.

Evaluation Studies as Topic↗

PubMed1993

[Hemorrhage of upper digestive and respiratory tracts in children. A clinical, biological and therapeutic approach].

Haemorrhages in the upper aero-digestive tract, whether spontaneous or provoked by surgery, lead to the discovery of abnormal coagulation. A retrospective series of 43 children hospitalized for haemorrhage of the upper aero-digestive tract enabled us to evaluate the most frequent causes. Willebrand's disease, haemophilia and Glanzmann's thromboasthenia, primary haemostasis disease, made up 27.9% of the cases; acquired impaired haemostasis by thrombopathies secondary to aspirin intake accounted for 25.6%; finally the haemostasis tests were normal in 46.5% of the children. Based on clinical features and biological data, we proposed an adapted diagnostic approach and discussed therapy in light of the current literature. This study confirmed the importance of an adapted routine battery of laboratory tests and the persistent search for impaired haemostasis in children hospitalized for haemorrhage of the upper aero-digestive tract.

Adolescent↗

PubMed1993

[Oropharyngeal origin of septic thrombophlebitis of the internal jugular vein. Apropos of 3 cases].

While before antibiotics cases of septic thrombophlebitis of the internal jugular vein secondary to oropharyngeal infection were frequent and had a poor prognosis, today they are exceptional and often have a favourable course under antibiotic therapy. The clinical features are often limited to fever and a painful tumefaction of the anterior border of the sterno-cleido-mastoidian muscle, symptoms may be more pronounced in the Lemierre syndrome in which the anaerobic septicaemia is associated with secondary, especially pleuro-pulmonary, localizations. The diagnosis can be confirmed with a cervical CT-scan showing an enlarged, thrombosed vein which does not opacify and has a hyperdense periphery. Treatment is based on parenteral antibiotics adapted to anaerobic germs.

Adult↗