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Biomedical subjects

C Dubreuil

Publications and source records attributed to C Dubreuil.

At least 19 recordsLinked to original sources
PubMed1992

Neoadjuvant combination of carboplatin and 5-FU in head and neck cancer: a randomized study.

A prospective, randomized, multicenter study of patients with oropharyngeal and pharyngolaryngeal tumors compared locoregional treatment alone with neoadjuvant chemotherapy with carboplatin/5-fluorouracil (5-FU) followed by locoregional treatment. The aim of the study was to evaluate the role of chemotherapy on survival and on the need for mutilating surgery. Since 1988, 219 patients (105 with oropharyngeal and 114 with pharyngolaryngeal tumors) have entered the study. All patients randomized to neoadjuvant chemotherapy received three cycles of carboplatin 400 mg/m2 day 1 and 5-FU 1 g/m2/d as a continuous infusion days 1 through 5 every 3 weeks. Neoadjuvant chemotherapy was given to 108 patients. The 268 evaluable courses induced a low rate of grade 3 or 4 toxicity. Four patients (3.6%) died of major complications. The complete response (CR) rate was 31%, which represented a decrease in mutilating surgery of 30%. (Patients with CRs had radiotherapy alone instead of radiosurgical treatment as originally planned.) The objective response rate was 61%. Survival curves for the chemotherapy and chemotherapy-naive groups were not significantly different. The rate of nodal recurrence was significantly higher in the chemotherapy group, however, and chemotherapy did not decrease the rate of second primary tumors or distant metastases. Thus, the justification for neoadjuvant chemotherapy may be a decreased rate of mutilating surgery. These preliminary results are encouraging, but follow-up is as yet too short to allow definite conclusions.

Adult↗
PubMed1992

Effects of celiprolol, a cardioselective beta-blocker, on respiratory function in asthmatic patients.

The aim of this study was to compare the pulmonary effects of a single dose of celiprolol 400 mg, versus bisoprolol 20 mg and the combination of celiprolol 400 mg plus propranolol 40 mg versus placebo plus propranolol 40 mg. We conducted a double-blind randomized cross-over study in 10 stable asthmatic patients (mean age +/- SD 31 +/- 7 yrs) with forced expiratory volume in one second (FEV1): 2.5 +/- 0.7 l. A three-day washout period preceded each treatment period. Measurements of respiratory function were done before treatment and after 90, 120 and 180 min. There was a significant increase of FEV1 (+12%) and forced vital capacity (FVC) (+8%) after celiprolol (p less than 0.05) and a decrease of FEV1 (-9%) after propranolol. Concerning the combination, celiprolol inhibits the bronchoconstrictor effects of propranolol. We conclude that celiprolol has bronchosparing properties in asthmatic patients, and even improves some of the ventilatory parameters.

Adrenergic beta-Antagonists↗
PubMed1991

Betahistine dihydrochloride versus flunarizine. A double-blind study on recurrent vertigo with or without cochlear syndrome typical of Menière's disease.

This study was designed to compare the efficacy and safety of betahistine dihydrochloride and flunarizine. All patients included in this multicenter, double-blind, randomized trial showed a specific pattern of vertigo, i.e. recurrent paroxysmal vertigo with or without the cochlear symptoms typical of Meniere's disease. Fifty-five patients were treated for 2 months (28 in the betahistine group and 27 in the flunarizine group). Analysis of intra-group symptom changes demonstrated a greater efficacy for betahistine. Statistically significant decreases in duration and severity of attacks, and in the presence of vegetative symptoms were seen in the betahistine group after the first and second months of treatment, whereas in the flunarizine group this was the case only at the end of the first month of treatment. Furthermore in the betahistine group, statistically significant decreases occurred for the other major criteria, including number of attacks, evidence of vestibular dysfunction, and presence of cochlear symptoms. Adverse effects were similar to those reported in previous studies of both products: stomach pains only with betahistine, and drowsiness, asthenia, and depression with flunarizine.

Betahistine↗
PubMed1991

[Value of oto-endoscopy in the follow-up treatment of cholesteatoma of the middle ear].

The endoscopic approach to the middle ear in eradication of cholesteatoma is now very frequently realised as in the control of the cavities of the middle ear in second stage of cholesteatomas for revision. The improvement of eradication will help to prevent recurrent cholesteatoma and to manage ossiculoplasty. Retraction pockets must also lead to endoscopic control and management.

Cholesteatoma↗
PubMed1991

Microflora of the nasopharynx in Caucasian and Maghrebian subjects with and without nasopharyngeal carcinoma.

The possible role of bacteria in the etiology of nasopharyngeal carcinoma (NPC) was studied by bacteriological and biochemical analyses of nasopharyngeal swabs collected in the cavum and in the fossa of Rosenmüller of NPC patients and healthy controls in France and Algeria. Counts of total bacteria and of total nitrate-reducing bacteria, mainly enterobacteria, were higher in the Maghrebians than in the Caucasians. The composition of the bacterial flora was different: in Maghrebians, enterobacteria were present in five of 17 control subjects and eight of 15 NPC patients, while the prevalence was only one out of 15 control subjects in Caucasians. Twelve of 32 bacterial species isolated from Caucasians and Maghrebians with normal or tumorous nasopharyngeal microflora were able to catalyse nitrosation of morpholine in vitro. This result suggests that colonization of the nasopharynx by microflora that contain nitrate-reducing microorganisms which can form N-nitroso compounds might represent a risk factor for NPC in Maghrebian populations.

Algeria↗
PubMed1991

[Treatment of acute otitis media: comparative study of efficacy of cefatrizine and amoxicillin-clavulanic acid].

Fourty hospitalized patients (15 children, 25 adults) suffering from acute otitis media have been treated with either cefatrizine or amoxycillin-clavulanic acid. Bacteriological samples were done during surgery by tympanocentesis (N = 33) or by sampling of middle ear fluid specimens (13). H. influenzae was the most common isolate, following by Enterobacteriaceae, S. aureus, P. aeruginosa, and S. pneumoniae. We conclude that these two antibiotics can be used for treatment of acute otitis media in our country even in adults where the order of frequency of bacteria is different from those reported in children.

Acute Disease↗
PubMed1990

Shape change of the occlusion-pressure wave during exercise.

In conscious subjects, the occlusion pressure measured in the initial part of the inspiration (up to 200 ms) appears to be a valid index of output of the respiratory centres. To interpret any relative change in occlusion pressure, the shape of the occlusion-pressure wave must remain absolutely constant. The purpose of this study was to test the hypothesis that the shape of occlusion-pressure wave does not change during exercise. However, we found that the shape changed significantly during cycle incremental-load exercise in five healthy subjects and in 12 of 17 patients with chronic obstructive pulmonary disease. The major change appeared during the second half of the exercise and mainly during the last workloads. This study shows that it is necessary to take into consideration this form change to interpret any relative change in mechanical transforms of the inspiratory neural output such as pressure at 0.1 s (P0.1) and mean inspiratory flow (VT/TI) or their ratio. This finding confirms, in direct fashion, the expected form change from previous data in which P0.1 is thought to measure the rate of change in chest wall muscle pressure (Pmus) over a segment somewhat removed from the onset of neural inspiration.

Adult↗
PubMed1990

[Preservation of the stapedial muscle in the treatment of otospongiosis, apropos of 48 cases].

The surgical management of otosclerosis, using drilling of the foot plate with a 8 mm diamond burr, 4 mm diameter, teflon prosthesis and vein graft, seems to be in our experience the safest procedure. However, we have tried to keep the function of the stapedial muscle in 48 patients to study the effects on hearing improvement, the stapedial reflex conservation, the protection of inner ear during the six months after surgery. The original technique and results are reported. After surgery, we have not observed any case of painful amplified hearing or of resonance. The audition is reestablished like with the usual techniques.

Audiometry↗
PubMed1990

[A visual analog scale of exercise dyspnea].

We have adapted a visual analogue scale (VAS) to make repeated measurements of the sensation of dyspnoea during an exercise test on a bicycle ergometer. We tested the reproducibility of the development of the VAS as a function of work load and its sensitivity in detecting changes in the sensation of dyspnoea induced by the addition of an inspiratory resistance or by a trial of oxygen administration in 13 patients who were dyspnoeic on effort. The reproducibility was acceptable providing to perform a preliminary test and to eliminate the rare subjects who was incapable of performing the test (1/13). The method turned out to be equally sensitive as to the effect of inspiratory resistance for 8/12 patients and for the oxygen enrichment of inspired air for 8/9 patients. This scale thus provides a reproducible and sensitive estimation of the sensation of dyspnoea during effort and thus appears valuable in evaluating the subjective response in therapeutic trials in patients who are dyspnoeic on effort.

Aged↗
PubMed1989

Regulation of muscle AChR alpha subunit gene expression by electrical activity: involvement of protein kinase C and Ca2+.

Using primary cultures of chicken myotubes, we investigated the involvement of protein kinase C and Ca2+ in the repression of nicotinic acetylcholine receptor (AChR) biosynthesis by electrical activity. Treatment with the Ca2+ channel blocker verapamil or the Na+ channel blocker tetrodotoxin increased alpha subunit mRNA levels 11.5- to 15-fold. The effect of tetrodotoxin was abolished in the presence of the Ca2+ ionophore A23187. Dantrolene, which blocks Ca2+ efflux from the sarcoplasmic reticulum, caused only a 1.7-fold increase in alpha subunit mRNA levels. Down regulation of protein kinase C by prolonged exposure to the phorbol ester TPA or inhibition of protein kinase C by staurosporine led to 8- to 10-fold increases in alpha subunit mRNA levels. Mature and precursor forms of AChR alpha subunit mRNA were found to vary in parallel throughout all of these treatments, suggesting that protein kinase C and Ca2+ ions may modulate AChR alpha subunit biosynthesis at the transcriptional level.

Animals↗
PubMed1989

Auditory evoked potentials during propofol anaesthesia in man.

The effects of propofol on auditory evoked potentials were studied in nine patients undergoing otorhinolaryngology surgery. After recording of basal evoked potentials patients received propofol 2 mg kg-1 over 2-3 min for induction of anaesthesia. Potentials were recorded every 10 min (T1, T2, T3). During T1, T2, T3, the infusion rates of propofol for maintenance of anaesthesia were respectively 7, 5 and 3 mg kg-1 h-1 consecutively. Middle latency component was affected markedly. Brainstem waves latencies I, III, V were increased significantly, while amplitude waves I, III, V remained constant.

Adult↗
PubMed1989

Exercise tolerance in chronic obstructive pulmonary disease: importance of active and passive components of the ventilatory system.

We investigated which components of ventilatory function are related to exercise tolerance in chronic obstructive pulmonary disease (COPD) patients. Physical characteristics, usual lung function, timing and neuromuscular components of ventilation were measured in 113 outpatients in whom FEV1/VC was less than 75% of the predicted value and exercise was limited by breathlessness. These variables were used to predict the maximum work load during progressive bicycle exercise. The prediction was obtained using a stepwise procedure in men and women separately. Among the variables selected, age, body weight, FEV1/VC, PImax, and P0.1/VT/TI accounted for 79% of the variability in maximum performance in men. The predictive model was statistically verified and was stable. The mean prediction error was 12 Watts. Among these variables, P0.1/VT/TI, PImax, and FEV1/VC were the main determinants of maximum work load (MWL). These results show that exercise limitation in COPD is related to impairment of both the active (inspiratory muscles) and passive (respiratory impedance) components of the ventilatory system. The same conclusions concerning passive components are proposed for women, despite a smaller population which prevented verification of the prediction.

Adult↗
PubMed1989

Tumor size-dependent elevations of serum gangliosides in patients with head and neck carcinomas.

Serum gangliosides were studied in 100 patients with benign or tumoral head and neck lesions. Whereas very few changes over the normal level were noticed in benign cases, 78% of patients with head and neck carcinomas had a significant elevation of serum gangliosides, mostly accounted for by GM3 and GD3. Such an increase was correlated with the observed tumor size, and the level of serum gangliosides returned to normal within one month after surgery. Follow-up of patients showed that further elevations of serum gangliosides were associated with relapses.

Biomarkers, Tumor↗