Search PubMed⌕ Search

Biomedical subjects

B Fleury

Publications and source records attributed to B Fleury.

At least 37 records · Page 2Linked to original sources
PubMed1999

Economic studies and 'technical' evaluation of telemedicine: the case of telemonitored polysomnography.

Information and communication technology (ICT) is not yet integrated into current medical practice and frequently, organizational patterns of health care production are held responsible for this situation. However, and quite paradoxically, measures recently taken in France indicate that a preferential role is granted to ICT in order to promote the development of healthcare networks. In this context, one should carefully examine which factors, other than organizational ones, can explain the very slow diffusion of telemedicine. Actually, medical assessment of telemedicine is very seldom and the medical community is unable to appreciate the extent that this technology would modify the quality of care provided. Furthermore, and as a consequence of the former, there is no economic evaluation of telemedicine applications and its effects, in terms of productivity, remain virtual. In this article, based on an early evaluation of telemonitored polysomnography to diagnose sleep apnea syndrome, we show that it is possible, even at an experimental stage, to produce appropriate and convincing clinical results stating the true technological effectiveness (choice of an adequate clinical trial, selection of appropriate endpoints). Specific attention is given to the technical conditions in which the technology is assessed, we also provide most of the data that should be taken into account to foresee the major organizational transformations of the production processes. Our results show that early clinical ad hoc evaluations of telemedicine applications can be conducted promptly, providing strong clinical results and useful data for any forthcoming economic evaluation.

Adult↗
PubMed1999

Tongue base reduction with hyoepiglottoplasty: a treatment for severe obstructive sleep apnea.

OBJECTIVE: To describe a surgical procedure for the treatment of severe obstructive sleep apnea syndrome (OSAS), the procedure's indications, and its results. STUDY DESIGN: A retrospective study of 10 male patients with OSAS treated by tongue base reduction with hyoepiglottoplasty (TBRHE) at the Foch Hospital (Suresnes, France) between 1994 and 1997. Patients had a mean body mass index (BMI) of 32 kg/m2, a mean respiratory disturbance index (RDI) of 70 events/h, and a mean minimal oxygen saturation of 78%. They had refused positive airway pressure therapy or wished to discontinue it. METHODS: Subtotal tongue base reduction preceded by lingual neurovascular bundle identification and derouting, epiglottal verticalization, mouth floor horizontalization, and hyoid bone repositioning was performed, associated in some cases to uvulopalatopharyngoplasty (UPPP). Indications were based on a site-related obstruction, on the absence of craniofacial deficiencies, and on the presence of hyolingual abnormalities determined by cephalometry and magnetic resonance imaging. RESULTS: TBRHE associated to UPPP in most cases had an 80% success rate, based on a postoperative RDI below 20 events/h and a reduction of the preoperative RDI of more than 50%. Snoring and excessive daytime sleepiness decreased or disappeared, respectively, in 100% and 90% of the cases. No neurovascular complications occurred. CONCLUSION: TBRHE is a safe procedure for the neurovascular bundle. Associated to a pharyngotomy, it is an effective treatment for severe OSAS attributable to tongue base obstruction. These results require confirmation in a larger series of patients.

Adult↗
PubMed1999

[Pharyngeal muscles and sleep obstructive apnea syndrome].

An analysis of the way the pharyngeal musculature modulates the caliber of the pharynx is important to better understand and treat obstructive sleep apnea syndromes. The caliber of the pharynx at the soft palate depends on the action of the tensor veli, the palatoglossus, the palatopharyngeus and the uvula muscles. At the ligual level, the action of the genioglossus and the geniohyoideus predominate. These different muscle groups contract in co-ordination before the diaphragm contracts. Their activity is diminished and disorganized during sleep. These muscles appears to have a histological composition adapted to short-duration intense contractions making them vulnerable to fatigue. In apneic patients, these muscles are solicited constantly. Muscular lesions related to overwork have been suggested. The histological composition of these muscles is modified in apneic patients compared with non-apneic subjects (increased number of type IIa fibres), the expression of an adaptive process. The degree of adaptation varies depending of the pharyngeal level considered. Similar to their reflex stimulation, the response of these pharyngeal muscles to increased resistance is probably greater at the soft palate level. Greater solicitation of palatine muscles associated with their greater vulnerability to fatigue could explain why obstruction is particularly important at this level. A study of the mechanical and histological properties of the pharyngeal musculature is required for a better understanding of the occlusive mechanisms of the upper airways and must be undertaken before initiating therapeutic stimulation of these muscles.

Humans↗
PubMed1998

Cross-clade-specific cytotoxic T lymphocytes in HIV-1-infected children.

We studied cytotoxic T lymphocyte (CTL) cross-reactivity between human immunodeficiency virus type 1 (HIV-1) subtypes within a group of infants infected with either HIV-1 B or non-B clade. Fifteen children were infected with a clade B virus. Nine were infected with non-B virus, including two clade A, four clade D, two clade F, and one clade G. CTL activities from in vitro activated peripheral blood mononuclear cells were tested against autologous cell line infected with recombinant vaccinia viruses encoding for Env, Gag, Pol, or Nef proteins from a clade A or B isolate. HIV-1-specific CTL elicited from infection with clade B virus could lyse targets expressing clade A proteins, and vice versa. In infants with positive CTL responses, cross-clade recognition was predominant and was detected within 88% of the Pol, 83% of the Nef, 67% of the Gag, and 55% of the Env responders. Longitudinal studies showed that CTL cross-reactivity to both B and A targets was stable for several years. Elicitation of CTL reactivities capable of elimination of virus-infected cells is an important goal for the development of an efficient AIDS vaccine. The significant cross-reactivity of CTL shown in this study supports the concept that vaccines developed using a single-clade immunogen may be applicable to induce broadly reactive T cell responses.

Child↗
PubMed1998

[Tongue base reduction with hyoid-epiglottoplasty. A surgical alternative in severe sleep apnea syndromes].

We present preliminary results and indications of tongue base reduction with hyo-epiglottoplasty for the treatment of severe obstructive sleep apnea syndrome (OSAS) due to isolated hyolingual abnormalities. The procedure consists in a subtotal resection of the tongue base after identification and derouting of the lingual neurovascular bundle. Hypopharyngeal enlargement, epiglottis verticalization, floor of the mouth tension and hyoid bone repositioning are also performed during the procedure. 14 severe OSAS male patients (mean apnea-hypopnea index of 71) were treated in our institution from November 1992 to February 1996. Indications were determined after a cephalometric analysis and a magnetic resonance imaging evaluation. Results were evaluated on clinical and polysomnographic criteria. No neurovascular complications occurred. Clinical results were excellent but success rate based on polysomnography was 50%. These preliminary results led us to change some of the steps in the technique. We also identified a predictive factor of success on the cephalometrics: an oropharyngeal area greater than 25 cm2.

Adult↗
PubMed1997

Laryngeal and oropharyngeal cancer, and alcohol dehydrogenase 3 and glutathione S-transferase M1 polymorphisms.

In this study the GSTmu phenotype and ADH genotype at the ADH3 locus were investigated in a group of 39 alcoholic men with upper respiratory/digestive tract cancer: 21 with oropharyngeal cancer and 18 with laryngeal cancer. The results are compared with those of a control group of 37 alcoholic men without alcohol-related medical complications. Of the control subjects, 48% were found to be GSTmu deficient [GSTmu(-)] and 19% carried the ADH(3)1/ADH(3)1 genotype. In the laryngeal cancer patients, a significantly elevated frequency of both the GSTmu(-) (78%) and ADH(3)1/ADH(3)1 genotype (56%) was observed, relative to the control group. On the basis of this result, the risk of laryngeal cancer associated with the GSTmu(-) and ADH(3)1/ADH(3)1 genotypic combination within the population of alcoholics was estimated to be 12.9 with a 95% confidence interval of 1.8-92 (P < 0.01) relative to alcoholic individuals who have GSTmu [GSTmu(+)] and are not ADH(3)1/ADH(3)1. Thus, alcoholics who are GSTmu(-) and ADH(3)1/ADH(3)1 have at least an 80% greater risk of developing laryngeal cancer than alcoholics who are GSTmu(+) and who are not ADH(3)1/ADH(3)1. In addition, the oropharyngeal cancer patients had excess frequencies of both GSTmu(-) (62%) and ADH(3)1/ADH(3)1 (43%) relative to the control group, but these excess frequencies were not statistically significant. The GSTmu(-) and ADH(3)1/ADH(3)1 genotypic combination may be a constitutional risk factor for laryngeal cancer among alcoholics.

Adult↗
PubMed1997

[Cost-effectiveness study of 2 long-term home oxygen therapy management systems].

In France, home oxygen therapy for patients with chronic obstructive pulmonary disease (COPD) is carried out by nonprofit associations (NP) or profit-making health organisations (PM). In a retrospective pragmatic approach we analysed the costs and the effectiveness of these 2 types of structures delivering oxygen at home. Between July 1985 and March 1994, 234 patients were involved in the survival study (chosen as an effectiveness indicator), 24% in PM and 76% in NP. The economic appraisal was performed, from the insurer's point of view, on a representative sample of 61 patients and analysed in detail all the ambulatory costs for respiratory care. Patient survival was similar in both types of structures (Cox model). Oxygen therapy represented the largest share of the total ambulatory cost (81.6% in PM and 72.1% in NP). The NP structures were less costly for reasons linked to their preference for concentrator (p = 0.004 in a Wilcoxon test), all the other direct costs being non-statistically different. NP structures had a significant influence on a low level of ambulatory costs (adjusted OR = 10.98, p = 0.0004) in logistic regression. As oxygen treatment plays an important role in the variation of costs, further pragmatic studies should help to better understand what are the real motivations to choose one mode of oxygen administration more than an other and should determine factors that may sometimes lead physicians not to comply with clinical guidelines (actually a quarter of the patients did not have a PaO2 < 60 mmHg).

Aged↗
PubMed1996

Memory cytotoxic T lymphocyte responses in human immunodeficiency virus type 1 (HIV-1)-negative volunteers immunized with a recombinant canarypox expressing gp 160 of HIV-1 and boosted with a recombinant gp160.

A vaccine against human immunodeficiency virus (HIV) should induce virus-specific cytotoxic T lymphocyte (CTL) activity. Immunization of uninfected volunteers with a canarypox virus expressing HIV envelope was carried out in a phase I trial. Two injections of canarypox expressing HIV-1MN gp 160 (months 0 and 1) were followed by two boosts of recombinant envelope protein (months 3 and 6). HIV envelope-specific CTL were detected in peripheral blood mononuclear cells stimulated with autologous HIV-1-infected blast cells. T cell lines were obtained from 18 of 20 donors: CTL were detected at least once following immunization in 7 (39%) of these 18. This activity was mediated by major histocompatibility complex class I-restricted CD3+CD8+ T cells. For two subjects, this activity was still present 2 years after the initial immunization. The CTL responses with this prime-boost regimen are the best observed with any HIV vaccine tested in humans.

AIDS Vaccines↗
PubMed1996

A laboratory validation study of the diagnostic mode of the Autoset system for sleep-related respiratory disorders.

We performed a validation study of the diagnostic mode of the Autoset system (ResMed, Australia) on a group of 44 snorers (10 women). We compared the result of the Autoset's automatic analysis of nasal airflow (using nasal prongs) to those of an in-laboratory polysomnographic study with a Fleisch facemask pneumotachograph. For the first 29 patients, the Autoset software was set to recognize only apneas; for the remaining 15, the software was modified to recognize both apneas and hypopneas. Relative to polysomnography, the Autoset overestimated the number of apneas. Oral breathing or displacement of the nasal prongs partially explained these differences. A significant correlation was found between the apnea indices (AI) assessed by the two methods (r = 0.98). For an AI of 20/hour the Autoset was 100% sensitive and 88% specific. The Autoset significantly underestimated the number of hypopneas compared to the polysomnograph with pneumotachograph (62.9 +/- 4.7 vs. 85.5 +/- 73.1, P = 0.04), although for an apnea-hypopnea index of 20, Autoset was 100% sensitive and 88% specific. The lack of linearity of Autoset's volume evaluation at low volumes could explain most of the differences. Our results indicate that the Autoset system, in its diagnostic mode, is a useful tool for identifying patients with significant obstructive sleep apnea syndrome. The system is less useful in patients with mild to moderate sleep disordered breathing, where it may give erroneous results.

Adult↗
PubMed1996

Objective patient compliance in long-term use of nCPAP.

Concerns remain regarding patient compliance with nasal continuous positive airway pressure (nCPAP). Poor objective compliance during the first months of treatment has been reported, but no data are available among chronically treated patients. Use of nCPAP, in 17 chronically treated obstructive sleep apnoea patients (820+/-262 days) was evaluated objectively using a pressure monitor (MC+; Sefam, France). Two consecutive recording periods of 30 sessions of treatment were scheduled at the patient's home. To minimize the potential bias caused by the introduction of the monitor, only the pressure data obtained at the end of the second period of recording (T2) were analysed. During the 28.1+/-2.6 monitored days, the mean effective daily rate of use was 7.1+/-1.1 h, 97% of the rate indicated by the standard in-built time counter. The prescribed pressure was observed during 95% of the machine run time. The nCPAP system was used for 94% of the monitored days. Sixty percent of the patients used their device every day. These preliminary results suggest that, contrary to reported compliance during the early period of the treatment, objective use of nasal continuous positive airway pressure therapy in chronically treated patients is satisfactory.

Female↗
PubMed1996

The cost of treating COPD patients with long-term oxygen therapy in a French population.

OBJECTIVE: In greater Paris and its surrounding (as it is in all France), oxygen is home delivered by not-for-profit (NP) associations or profit-making (PM) health organizations. Both are financed by the national health insurance. This dual context and the current economic climate justify an economic evaluation of all respiratory care for patients with COPD receiving long-term oxygen therapy (LTO). This pragmatic approach identifies the variables that have the greatest impact on direct medical costs and estimates the annual cost for respiratory care per COPD patient. DESIGN: Retrospective study. SETTING: Health insurance scheme for self-employed professionals (CANAM). PATIENTS AND METHODS: Between July 1985 and March 1994, 234 patients registered in CANAM files began LTO, 24% in the PM sector, 76% in the NP sector, mainly using concentrator (78%), mean age of 74 +/- 10 years, male predominance (74%), PaO2 of 56.2 +/- 10.5 mm Hg, FEV1/FVC of 43 +/- 15%, and 51% having 1 or more severe illness(es) associated. The economic appraisal was performed on a representative sample of 61 patients and measured the total resources consumption for respiratory care per COPD patient and per year (physician visits and tests, drugs, physiotherapy, oxygen therapy, hospitalizations for acute respiratory failure, transport costs). RESULTS: A quarter of the patients in each sector did not meet the LTO prescription guidelines (PaO2 > 60 mm Hg). For patients having their oxygen delivered by NP sector, the total ambulatory cost for respiratory care was lower ($4,506 per patient and per year vs $5,399) because they mainly used concentrator, all the other direct ambulatory costs being equal. The total annual cost for respiratory care of a COPD patient receiving LTO amounted to $11,672 (NP and PM sectors merged). Oxygen therapy represented 73% of the total ambulatory cost. In a multiple linear regression model, hospitalization represented the largest share of cost, significantly higher when PaO2 was 55 mm Hg or less ($2,287 per patient per year vs $8,717). In contrast, none of the covariates (age, sex, PaO2, FEV1/FVC) influenced at a significant level the total cost of visits, tests, drugs, and physiotherapy, amounting to $1,507. CONCLUSION: As oxygen treatment plays an important role in the variation of costs, further pragmatic studies should help to better understand what are the real motivations to choose one mode of oxygen administration more than another and should determine factors that may lead physicians sometimes not to comply with clinical guidelines.

Aged↗
PubMed1995

Enhancement of postoperative desaturation in heavy snorers.

The risk of postoperative decreases of arterial saturation in oxygen (SpO2) could be enhanced in patients with previous history of sleep-induced respiratory impairment. To test this hypothesis, patients scheduled for orthopedic surgery were classified preoperatively as heavy snorers, light snorers, and nonsnorers, according to their answers to a questionnaire. During the first postoperative night, the patients were breathing room air and both the arterial saturation and the tracheal sounds were monitored. Although the cumulated duration of snore was similar in the three groups, the number of desaturations (decrease in SpO2 > or = 4%) was more in the heavy snorers (14.9 +/- 27.9) than in the light snorers (0.1 +/- 0.3) and the nonsnorers (0.2 +/- 0.3) (P < 0.05). The percent duration of recording at SpO2 < 90% was longer in the heavy snorers (52.0% +/- 41.9% of the recording time) than in the two other groups: 9.3% +/- 12.4% (light snorers) and 17.5% +/- 21.8% (nonsnorers) (P < 0.05). Patients with a previous history of sleep-disordered breathing risked postoperative desaturation and could be detected preoperatively by the answers to certain questions.

Anesthesia, Inhalation↗
PubMed1995

[A new technique of gene transposition in the surgical treatment of sleep apnea syndrome].

Pharyngotomy appears to be insufficient for the treatment of severe sleep apnea. For patients who refuse or abandon mechanical ventilatory assistance, surgery can be used to widen the retrobasilingual space adapting it to the cephalometric profile defined by cineradiography and MRI in combination with velopharyngeal plasty. For patients with no maxillomandibular or lingual malformation, the pharyngotomy can be combined with an anterior transposition of the genial insertions of the tongue without rotation. A method different from that described by Riley and Powel is proposed. The details of the surgical procedure are exposed. The operation is indicated in snorers with sleep apnoea with an Apnea Index Superior to 30 who refuse nocturnal ventilatory assistance and who do not have a hypertrophied tongue (Surface less than 30 cm2) or maxillomandibular retroposition.

Cephalometry↗
PubMed1995

[Treatment of velopharyngeal stenosis after pharyngotomy for chronic snoring. Apropos of 13 cases].

Velopharyngeal stenosis is a rare complication of pharyngotomy (UPPP) for chronic snoring. Its treatment is hard because of its recidivant feature. The aim of this study was to determine a therapeutic strategy accorded to each stenosis from clinical and anatomical features of 13 velopharyngeal stenosis. Therapeutic behavior was function of patients complains, of the ground (associated chronic rhinosinusitis and obstructive sleep apnea) and clinical findings (partial or total stenosis, tonsil remainders, short or long residual soft palate). From these data, treatment was medical (1 case) or surgical (12 cases), searching lateral velopharyngeal mucosa recovery in order to avoid recidive of stenosis. This aim needed locoregional mucosal grafts in 4 patients with short soft palate. Patients complains were improved in all cases and there was no patient with recurrence of stenosis. The best treatment of velopharyngeal stenosis still remains a preventive one, by respecting a severe surgical technique during pharyngotomy for chronic snoring.

Adult↗
PubMed1994

[Respiratory effects of midazolam in patients with obstructive sleep apnea syndromes].

The administration of benzodiazepines at sleeping doses can be followed by an increased rate of upper airways obstruction episodes, especially in patients with an obstructive sleep apnea syndrome (OSAS). However, the effects of benzodiazepines at premedication doses have not yet been assessed. Therefore, fourteen patients were studied after administration of midazolam 0.08 mg.kg-1 i.m.: seven with an OSAS diagnosed previously (baseline recording) (= OSAS group) and seven without risk factors for OSAS (= Control group). The recordings were undertaken in the sleep laboratory. The airflows were assessed by nasal and oral thermistors and chest and abdominal movements by strain gauges. The electromyogram of the chin muscles was recorded, the electroencephalogram and the electro-oculogram electrodes were placed as described by RECHTSCHAFFEN and KALES. The arterial saturation in oxygen (Spo2) was monitored by pulse oximetry. All the signals were digitized and fed into a computer. The apnea was defined as a cessation of airflows for a least 10 s. The hypopnea was defined as a 10 s decrease in airflow with a drop in Spo2 of 4% or more. The respiratory event (apnea or hypopnea) was qualified as obstructive if the thoraco-abdominal movements persisted. The rate and the duration of respiratory events per sleep hour (mean +/- SEM) in OSAS group after midazolam (respectively 29.6 +/- 10 and 11.2 +/- 3.5 min) were not different from those of the baseline recording (respectively 38.4 +/- 11.6 and 12 +/- 3.5 min) and were significantly higher than in the control group (respectively 38.2 +/- 2 and 1.8 +/- 1.3 12 +/- 3.5 min) and were significantly higher than in the control group (respectively 3.8 +/- 2 and 1.8 +/- 1.3 min; p < 0.05). In the OSAS group, the percentage of sleeping time spent with a Spo2 < 90% was 1.5 +/- 1.4% during the baseline recording and 4.7 +/- 1.9% after midazolam (difference n.s.). However, a dramatic increase was observed in two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Long-term compliance to continuous positive airway pressure therapy (nCPAP) set up during a split-night polysomnography.

We studied prospectively the acute and long-term compliance with nasal continuous positive airway pressure (nCPAP) therapy set up during a split-night polysomnography in 31 patients suffering from severe obstructive sleep apnea syndrome (OSAS). The mean apnea-hypopnea index (AHI) was 66 +/- 23/hour. An effective nCPAP (AHI < 10/hour in all sleep stages in the dorsal decubitus) was titrated in 27/31 patients. The mean effective nCPAP was 11 +/- 2 cm H2O. In three patients, a subsequent night was necessary to determine the effective nCPAP during rapid eye movement sleep, and one patient did not support the treatment. Of the 27 patients with successful titration, 21 accepted home treatment, three chose a surgical procedure and three refused to be treated. Of the 21 accepting home treatment, one patient did not receive his insurance agreement and could not participate in follow-up. Among the 20 other patients, four interrupted their treatment during the 1st month because of discomfort, and 16 were followed for 285 +/- 84 days. The daily rate of nCPAP use for the compliant patients was 6.7 +/- 1.5 hours. These preliminary results indicate that a split-night technique is reliable and cost saving in a majority of patients suffering from severe OSAS.

Adult↗
PubMed1994

Multispecific and heterogeneous recognition of the gag protein by cytotoxic T lymphocytes (CTL) from HIV-infected patients: factors other than the MHC control the epitopic specificities.

The HIV gag polyprotein is a major target for recognition by CTL in infected humans. Using recombinant vaccinia viruses (rVV) expressing truncations of the p24gag, and the p18gag, p15gag and HIV-2 p56gag proteins, the characterization of epitope regions recognized by in vitro-stimulated peripheral blood mononuclear cells (PBMC) from 18 infected patients has been studied. The gag-specific response of most individuals is polyclonal and multispecific, and interindividual variations between target epitope regions were frequently observed, despite shared MHC alleles. As CTL may play an important role in the control of HIV replication in infected hosts, these results have important implications for designing vaccine strategies.

Adult↗