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B Bertrand

Publications and source records attributed to B Bertrand.

At least 37 records · Page 2Linked to original sources
PubMed2003

Piriform cortex functional heterogeneity revealed by cellular responses to odours.

The role of the piriform cortex (PC) in olfactory information processing remains mainly unknown. Indeed, until recently, only a few studies have investigated the response of PC neurons to odours and these studies did not take into account the functional heterogeneity of the PC previously described using an electrical stimulation paradigm. In this experiment, extracellular activity in response to odour was recorded in urethane anaesthetized rats in the different parts of the cortex ranging from anterior to posterior. A large percentage of cortical cells were silent at rest, and this percentage increased from anterior to posterior. Analysis of odour evoked activity revealed a large percentage of nonresponsive cells that increased from anterior to posterior. Cell activity was largely synchronized with breathing and different temporal patterns were observed. The anterior PC was characterized by odour-evoked responses phase-locked with the inhalation-exhalation transition period. By contrast, activity in the posterior PC was mainly phase-locked with inhalation or exhalation. These data confirm the spatial functional heterogeneity previously reported in the PC. Functional anatomy of the PC suggests that activity in the anterior PC can be mainly driven by afferent activity coming from the OB whereas posterior cells were certainly entrained by more complex mechanisms.

Animals↗
PubMed2003

Somaclonal variation in Coffea arabica: effects of genotype and embryogenic cell suspension age on frequency and phenotype of variants.

We determined how age of embryogenic cell suspensions affects somaclonal variation in five F1 hybrids of Coffea arabica L. Batches of plants were produced either directly from embryogenic callus, or after 3, 6, 9 and 12 months of embryogenic cell suspension culture. Seven phenotypic variants were characterized. Based on vigor and productivity of the regenerated plants, we classified the variants in order of increasing severity of physiological disorders as: Juvenile leaf color, Giant, Dwarf, Thick leaf (Bullata), Variegata, Angustifolia, and Multi-stem. The Dwarf, Angustifolia and Multi-stem variants were the most frequent among the regenerated plants (1.4, 4.8 and 2.9%, respectively). The frequency (f) of variants increased exponentially with the age (t) of the embryogenic suspension, in accordance with the function f = 0.99e(0.267t). For all genotypes, somaclonal variation was low (1.3%) in plants produced from embryogenic callus or 3-month-old cell suspensions and increased in frequency with increasing suspension age (6, 10 and 25% in plants produced from cell suspensions aged 6, 9 and 12 months, respectively). Large differences in somaclonal variation among genotypes were found only in plants produced from 12-month-old cell suspensions. For two genotypes, the oldest suspensions produced a majority of somaclonal variants (80-90%), whereas somaclonal variation ranged between 8 and 18% in the other genotypes. Cell suspension age and genotype also affected the type of variant produced. The severity of somaclonal variations increased with cell suspension age. For all genotypes combined, the Angustifolia variant was the most common. The other somaclonal variations were specific to certain genotypes or distributed randomly among the genotypes.

Cells, Cultured↗
PubMed2003

Transnasal repair of unilateral choanal atresia.

OBJECTIVES: To evaluate the outcomes of the surgical correction of unilateral choanal atresia using a transnasal approach. PATIENTS AND METHOD: Over a 36-months period (from 1999 to 2001), seven children underwent endoscopic endonasal repair of an unilateral choanal atresia using the microdebrider (powered instrumentation). At the end of the procedure, topical application of Mitomycin-C was performed. No postoperative nasal stenting was inserted. Clinical characteristics of these patients, CT scan examination, complications of the procedure and outcomes were analysed and compared to historical cases treated in the same institution from 1990 to 1998. RESULTS: Seven patients (2 M/5F) (age 6 to 46 months) presented with primary unilateral choanal atresia and were operated during the period from 1999 to 2001. All the patients were symptomatic before surgical correction. No patients showed other facial anomaly. Of the 7 patients procedures, 6 (85.7%) remained patent (follow-up range 12 to 36 months). Mean surgical repair per patient before obtaining patent choana was 1.14. One patient required surgical transnasal revision nine months after the initial procedure with a patent choanal after this second procedure (follow-up 9 months). Minor turbinoseptal synechiae diagnosed 6 months after the surgical correction occurred in one patient and was the only postoperative complication. When compared to historical cases of unilateral choanal atresia (19 patients from 1990 to 1998) repaired without endoscopic control and without Mitomycin-C, it was shown that this current method provided better results; mean surgical repair per patient; 1.14 vs 1.89 and 85.7% of patent choanae at twelve months vs 47.3%. CONCLUSION: An endoscopic endonasal approach without postoperative stenting, using the microdebrider seems to us the treatment of choice for unilateral choanal atresia. The exact role of the topical application of Mitomycin-C needs to be further investigated.

Child, Preschool↗
PubMed2003

Computer assisted surgery and endoscopic endonasal approach in 32 procedures.

UNLABELLED: Computer aided surgery (CAS) is now routinely introduced in the ENT surgical field especially in endoscopic endonasal surgery. OBJECTIVE: Using a frameless computer aided surgery for endoscopic endonasal approach (SurgiGATE ORL TM), we tried to evaluate the practical use of such a system, to calculate supplementary installation time of the procedure, to determine the number of matching attempt (referencing) before starting optonavigation and to determine its clinical accuracy. PATIENTS AND METHODS: Thirty two patients underwent endoscopic endonasal surgery with the help of CAS; 13 revision cases (2 nasal polyposis, 7 paranasal sinus mucoceles, 4 frontal recess stenosis) and 19 primary cases (16 inflammatory diseases, 3 benign tumor removal). Paired points matching was used as referencing before optonavigation. Clinical accuracy of CAS was calculated at two confidence points during optonavigation and measured in multiples of the pixel size on CT Scan. RESULTS: Number of matching attempts before starting optonavigation was; mean 1.8 (1-4). Supplementary installation time of the system was; mean 15 minutes (10-40). Clinical accuracy at two confidence points was always between 0.5 mm and 2 mm. (6 < 0.5 mm, 16 < 1 mm, 10 < 2 mm). There was no major complication during surgery neither no side effect due to the use of the CAS except for one case who presented a slight tongue edema due to a wrong position of the dynamic reference base (maxillary splint) during the procedure. CONCLUSIONS: CAS and optonavigation using the surgiGATE ORL TM is safe and efficient in endoscopic endonasal surgery. The accuracy of the system is sufficient and its use appropriate for primary either revision rhinologic procedures.

Adolescent↗
PubMed2002

Influence of affective and cognitive judgments on autonomic parameters during inhalation of pleasant and unpleasant odors in humans.

Hedonic tone is so salient in odor perception that several authors have used odors to induce affective states. Various studies have shown that the electrophysiological and psychophysiological response patterns induced by olfactory stimuli are different for pleasant and unpleasant odors, and that these types of odor activate brain structures differentially. These results suggest that odors are first categorized according to pleasantness. The objective of the present work was to study the possible existence of an involuntary affective categorization in olfaction. Given that certain variations in the autonomic system, such as skin conductance amplitude and heart rate, are not under the voluntary control of human subjects, we used such psychophysiological methods for this investigation. Our results indicate that unpleasant odors provoke heart-rate acceleration during both a smelling task (control condition: a task in which subjects had only to inhale odors) and a pleasantness judgment, but not during a familiarity judgment. These results suggest that subjects involuntarily categorize odors by their pleasantness.

Adult↗
PubMed2002

Modulation of visual event-related potentials by emotional olfactory stimuli.

The objective of the present study was to determine whether an olfactory prime could modulate behavior and visual event-related potentials (ERPs) obtained in response to a visual stimulation representing female faces. More specifically, we tested the hypothesis that a pleasant odor could have effects on face perception: behavioral effects on subjective emotional estimation of faces, and on associated response times, and electrophysiological effects on the N400 and late positive complex or LPC. Experiments were performed in which subjects had to decide whether the presented face was pleasant or not, while visual ERPs were recorded. Faces were always primed with either a pleasant odor or a neutral olfactory stimulus (pure air). In order to test the effect of subject's awareness, participants were not informed that an odor would be presented in the experimental sessions. Responses were significantly shorter for unpleasant faces. However, no behavioral effects of the pleasant odor on response time or on evaluation of face pleasantness were observed. Late ERPs evoked by faces were modulated by the presence of a pleasant odor, even when subjects were neither warned nor aware of the presence of the odor: in a frontal site and after the diffusion of the odor, the LPC (appearing 550 ms after the presentation of the visual stimulus) evoked by unpleasant faces was significantly more positive than the LPC evoked by pleasant faces. This effect could reflect an enhanced alert reaction to unpleasant faces are preceded by an (incongrous) pleasant odor.

Adult↗
PubMed2002

Psychophysiological correlates of affects in human olfaction.

Pleasantness and arousal have been identified as the main dimensions of affective responses to environment. Pleasantness is defined as the degree of favorable feelings a subject can experience under given circumstances. Arousal is defined as the degree of excitement (general activation) the subject feels under these circumstances. In visual and auditory modalities, many studies using measures such as facial electromyographic (EMG) activity and skin conductance (SC) have found those parameters to vary as a function of either pleasantness or arousal: for example, facial corrugator EMG activity covaries with the pleasantness dimension, while SC increases together with arousal. The first objective of this research is to study the possible covariation between peripheral measures and pleasantness/arousal in olfaction. We also examined the effect of odor intensity on facial and autonomic variations. The second objective was to investigate whether odors could evoke verbally specific emotions (e.g. joy, anger, fear, surprise, disgust or sadness) and also induce specific patterns of peripheral responses. Participants were exposed to 12 different odors while their facial and autonomic parameters were recorded, and estimated their intensity, pleasantness, and arousal capacity. Then, they chose between seven words for emotions (fear, anger, sadness, surprise, neutral, joy or disgust) to describe their reaction to the odor. As in vision, olfactory pleasantness covaries (negatively) with facial activity of the corrugator muscle, and arousal (positively) with skin conductance. No relationships were observed between physiological changes and variations in perceived intensity. Results also showed that emotions of "disgust" and "joy" were more frequently evoked verbally than any other emotions, and that only facial EMG activity distinguishes them (e.g. "disgust" vs. "joy" and "neutral state"). The results are discussed in terms of possible existence of two brain systems (defensive and appetitive), each of them being able to vary in metabolic arousal.

Adult↗
PubMed2002

Comparison of somatic embryogenesis-derived coffee (Coffea arabica L.) plantlets regenerated in vitro or ex vitro: morphological, mineral and water characteristics.

Coffea arabica L. plantlets obtained ex vitro after sowing somatic embryos produced in a bioreactor in horticultural substrate were compared with those obtained in vitro from the same embryo population under conventional culturing conditions on semi-solid media. The intensity and quality of aerial and root system development were compared. Shoot emergence was more efficient in vitro but rooting frequencies were low. In contrast, all ex vitro-regenerated embryos rooted. The cotyledon area of mature embryos produced in a bioreactor positively affected plantlet development when regeneration was carried out ex vitro. Embryos with an intermediate cotyledon area (0.86 cm2) had the highest rates of plant conversion ex vitro (63%), and also resulted in vigorous plantlets. Mortality was higher in nursery conditions, but better plant development was obtained. The quality of plantlets produced under ex vitro conditions was reflected in better growth of the aerial and root systems, and also by similar morphological, mineral and water status characteristics to seedlings. Unlike roots formed on semi-solid media, those produced in soil were branched, fine (30-50% had a diameter of less than 0-5 mm) and they bore root hairs. Leaves of plantlets regenerated ex vitro had a histological structure similar to that of seedling leaves, and a lower stomatal density (100 vs. 233 mm-2). Moreover, they were more turgid, as indicated by higher pressure potential (psiP) (0.91 s. 0.30 MPa) and relative water content values (97 vs. 93%). Furthermore, under in vitro conditions, leaves had larger stomata which were abnormally round and raised. Direct sowing of germinated somatic embryos resulted in the rapid production of vigorous plantlets under ex vitro conditions, whilst removing the need for problematical and costly conventional acclimatization procedures.

Coffea↗
PubMed2002

Autonomic nervous system responses to odours: the role of pleasantness and arousal.

Perception of odours can provoke explicit reactions such as judgements of intensity or pleasantness, and implicit output such as skin conductance or heart rate variations. The main purpose of the present experiment was to ascertain: (i) the correlation between odour ratings (intensity, arousal, pleasantness and familiarity) and activation of the autonomic nervous system, and (ii) the inter-correlation between self-report ratings on intensity, arousal, pleasantness and familiarity dimensions in odour perception. Twelve healthy volunteers were tested in two separate sessions. Firstly, subjects were instructed to smell six odorants (isovaleric acid, thiophenol, pyridine, L-menthol, isoamyl acetate, and 1-8 cineole), while skin conductance and heart rate variations were being measured. During this phase, participants were not asked to give any judgement about the odorants. Secondly, subjects were instructed to rate the odorants on dimensions of intensity, pleasantness, arousal and familiarity (self-report ratings), by giving a mark between 1 (not at all intense, arousing, pleasant or familiar) and 9 (extremely intense, arousing, pleasant or familiar). Results indicated: (i) a pleasantness factor correlated with heart rate variations, (ii) an arousal factor correlated with skin conductance variations, and (iii) a strong correlation between the arousal and intensity dimensions. In conclusion, given that these correlations are also found in other studies using visual and auditory stimuli, these findings provide preliminary information suggesting that autonomic variations in response to olfactory stimuli are probably not modality specific, and may be organized along two main dimensions of pleasantness and arousal, at least for the parameters considered (i.e. heart rate and skin conductance).

Adult↗
PubMed2002

Bacteriology of chronic sinusitis: the bulla ethmoidalis content.

OBJECTIVE: To study the microbiology of the bulla ethmoidalis of patients who suffered from chronic sinusitis. DESIGN: A prospective study performed at the Saint-Luc universitary clinic (University of Louvain) from June 1999 to December 2000. MATERIAL AND METHODS: Seventy seven patients underwent functional endoscopic endonasal surgery during this period for chronic sinusitis refractory to standard medical treatment. All the patients presented symptoms for more than 3 months. After Povidone-Iodine disinfection, samples were taken into the bulla ethmoidalis after its opening with an endoscopic endonasal control. Samples were transferred to the microbiology laboratory using a thioglycolate medium for aerobic and anaerobic cultures. RESULTS: One hundred forty eight samples were studied. Culture rate was 73.6%. Thirty nine samples remained sterile. In the 109 culture positive specimens, 135 bacterial isolates were recovered. The main results are: Staphylococcus coagulase negative: 31, Staphylococcus aureus: 22, Streptococcus sp: 20, other Gram positive Cocci: 5, Haemophilus influenzae: 4, non-fermentative Gram negative bacilli: 6, Enterobacteriaceae: 45, anaerobic bacteria: 2. CONCLUSION: Enterobacteriaceae or enteric gram negative bacilli were frequently encountered in the bulla ethmoidalis of patients suffering from chronic sinusitis. This report suggests that endoscopically guided culture obtained from the ethmoid sinus may accurate our understanding of the microbiology of chronic ethmoidal sinusitis and underline the importance of Enterobacteriaceae in this disease.

Adult↗
PubMed2002

Standard ENT clinical evaluation of the sleep-disordered breathing patient; a consensus report.

Sleep disordered breathing (SDB) patients usually undergo an ENT clinical examination before any therapeutic decision. This clinical examination would be predictive about the occurrence of Obstructive Sleep Apnea Syndrome, cost effective, reproducible and would determine the sites of obstruction in the upper airways. To achieve this, ENT specialists from Belgium, representatives of academic hospitals in the country, have tried to establish an updated work-up in the clinical evaluation of the SDB patients. History, risk factors evaluation, excessive daytime sleepiness, static and dynamic evaluation of the upper airways (velopharynx aspect, tonsils grading, Mallampati score, Müller's maneuver, fiberoptic evaluation) have been standardized in a consensus report easily accessible to the vast majority of ENT specialists. This consensus must be understood as a clinical work-up to perform before the monitoring of breathing during sleep.

Belgium↗
PubMed2002

Effect of nasal valve surgery by open-septorhinoplasty and lateral cartilage grafts (spreader grafts) on snoring among a population of single snorers. Preliminary report.

Snoring is traditionally considered more of a social nuisance than disease. The observation that nasal obstruction may modify breathing during sleep and daytime behavior and our clinical observations suggesting that some single snorer patients who had undergone surgery of the nasal valve for nasal obstruction complaints had presented a decrease in their snoring, led us to make a retrospective study on twenty nine patients. Eight of them were simple snorers. They underwent a surgery of the nasal valve under general anesthesia through an open septorhinoplasty during which lateral graft cartilages (modified spreader grafts) were set in place between septolateral cartilage and the anterior and superior edge of the nasal septum. Active anterior rhinomanometry (AAR), posterior active rhinomanometry (PAR) and a self-assessment of the nasal patency by the patient himself on a visual analog scale (VAS) were compared before and one year after surgery. Snoring was assessed by both bed partners according to a four step scale (none, slight, moderate and severe). No significant differences were found between AAR or between PAR. But significant differences were measured with VAS (for the left (p < 0.0001) and the right sides (p < 0.001). All patients but one demonstrated substantially decreased snoring. As there is no clear cut evidence of changes in nasal resistances measured by rhinomanometry, we suggest that the observed decrease in snoring may be induced by changes in the direction of the nasal airflow against the nasal mucosa which may produce by a reflex between mecanoreceptors of the nasal mucosa and muscles of the pharynx, an increased tonus of the muscles of the pharynx.

Adult↗
PubMed2002

Surgical treatment of the sleep-disordered breathing patient; a consensus report.

Sleep disordered breathing patients may undergo surgical treatment after history, clinical examination and polysomnographic study if they demonstrate upper airway obstruction. This article focus on the surgical treatment designed for these patients. Sino-nasal surgery, rhinopharyngeal procedure, velopharyngeal procedures (Uvulopalato-pharyngoplasty, Laser assisted uvulopalatoplasty, Radiofrequency tissue volume reduction) as well as base of the tongue procedures were discussed among a panel of Belgian ENT specialists offering their experience in this field. Algorithm on corrective surgery as well as guidelines for postoperative management are proposed in the management of sleep disordered breathing patients.

Belgium↗
PubMed2001

Trueness-to-type and agronomic characteristics of Coffea arabica trees micropropagated by the embryogenic cell suspension technique.

Trueness-to-type and agronomic characteristics of trees of four coffee (Coffea arabica L.) F(1) hybrid clones derived from embryogenic cell suspensions were compared with those of trees produced from in vitro microcuttings. Three types of variants were observed among the 644 trees derived from embryogenic suspensions. Total frequency of the variants was 2.1% for trees originating from embryogenic cell suspensions, whereas no variant was found among the trees produced from microcuttings. The variant known as "thick leaf" had thick leaves, many abnormally starry flowers and low yields of large fruit. The "dwarf" variant was characterized by slow growth and small fruit. The "dwarf peaberry" variant had abnormal seeds in a single cavity, in addition to the "thick leaf" and "dwarf" characteristics. Compared with normal trees, the variants differed in leaf density and number of chloroplasts per guard cell. The variants aside, there were no differences in the main agronomic characteristics between trees produced from embryogenic suspensions and those produced from microcuttings. For all four clones, the trees had vegetative characteristics, productivity, fertility, and bean biochemical, mineral and organoleptic characteristics that were identical to those of the controls. We conclude that it is possible to generate coffee trees commercially with normal agronomic performance from embryogenic suspensions, because the frequency with which somaclonal variants occur is limited.

Agriculture↗
PubMed2001

[Choanal atresia: a retrospective study of 39 cases].

The purpose of this study was to investigate the clinical characteristics and the surgical management in patients with choanal atresia. We performed a retrospective study at the Saint-Luc University hospital, Brussels, between January 1988 and June 2000. Surgical corrections were performed using different approach (transnasal endoscopic, transpalatal) and different instrumentations (urethral sounds, laser nd-YAG, laser CO2, microdebrider). Portex endotracheal tubes were inserted as nasal stents in the vast majority of the patients with bilateral choanal atresia. Thirty-nine children with choanal atresia (22 unilateral and 17 bilateral) (9: M, 30: F) were studied. 38 of them were surgically managed. Based on clinical inspection and On CT-Scan, choanal atresia was defined as membranous for 4 patients, osseous for 6 and mixte for 29. Associated congenital anomalies were found in 22.7% of unilateral and in 70.5% of bilateral choanal atresia (Total: 43.5%). Of those children with bilateral choanal atresia, 75% were asymptomatic after four surgical procedures. In children with unilateral choanal atresia, 45% were asymptomatic after one surgical correction and 100% after three surgical corrections. Four patients were managed using an endoscopic endonasal approach with the microdebrider and showed no evidence of recurrence. Outcome analyses of factors that may influence the results of surgery are difficult to establish since many different surgical options were taken during this period. However, it seems that bilateral choanal atresia is associated with more surgical corrections before achieving a normal nasal breathing than unilateral choanal atresia. After this review, our current strategy regarding the choanal atresia will be to begin with the endoscopic endonasal approach using the microdebrider (stents if bilateral) and to propose the transpalatal approach in case of recurrence.

Age Factors↗
PubMed2001

[Sinus-nasal polyposis: one-year outcome after endoscopic sinus surgery followed by topical corticosteroid therapy in 72 patients].

Nasal polyposis (NP) is considered as an inflammatory disease for which first line therapy is topical and/or oral corticosteroid. In this paper we attempted to determine the efficacy of endoscopic endonasal surgery followed by topical corticoid in 72 adults suffering from bilateral NP refractory to corticosteroid therapy and to delineate the clinical characteristics of this cohort of patients. NP was confirmed endoscopically and with computed tomography. Visual analog scale for the subjective evaluation and endoscopic examination of the paranasal cavities for the objective evaluation were obtained 3 and 12 months postoperatively. Endoscopic endonasal surgery was based on a radical removal of the NP with wide opening of all the sinuses in the vast majority of the cases. Topical corticoid therapy was started 2 months after surgery. Clinical characteristics of the 72 patients revealed: 29.2% of coexisting allergy; 34.7% of coexisting asthma; 19.4% with food and/or aspirin intolerance. Anterior and posterior ethmoid sinus and maxillary sinus were the most affected sinuses. 53.5% of our patients presented a stage II. One year after surgery we observed that 59.1% of our patients revealed a marked decrease of their symptoms with no polyp on nasal endoscopic evaluation, that 28.8% revealed a marked decrease of their symptoms with recurrence of the NP on nasal endoscopic evaluation and that 12.1% presented moderate to severe symptoms with recurrence of NP on nasal endoscopic evaluation. Based on this experience, we think that endoscopic endonasal surgery will continue to play an important role in the management of NP when the patient becomes refractory to corticoid.

Administration, Topical↗
PubMed2001

Is septal deviation a risk factor for chronic sinusitis? Review of literature.

INTRODUCTION: The purpose of this work is to examine the role of septal deviation in adults in the pathogenesis of chronic sinusitis. This evaluation would allow a better understanding of the contributing factors to this pathology and would improve results in their management. MATERIAL AND METHODS: This review was based on a Medline research over English and French literature published between 1980 and May 2001. Twenty-five papers were scrutinized. RESULTS: Few investigators examined the role of the deviated septum on sinus disease. Methodologies and results are often contradictory. Furthermore, these studies are mainly based on radiological imaging. In most studies, prevalence of septal deviation looks the same when having compared among patients with radiological rhinosinusitis and among general population. An increased incidence and severity of sinus disease correlated to an increasing angle of septal deviation in the ostiomeatal complex area is reported by Calhoun (7), Youssem (4), Matschke (18) et Elahi (20). One study (1) demonstrates a significant association between the shape of the nasal septum and the location of the sinus disease: septal crest is associated with homolateral sinusitis, "watch-glass shaped diformity" with controlateral sinusitis. Stammberger (21, 25) suggests a pathophysiological role of the septum through a mechanical obstruction on the ostiomeatal complex; Danese (1) and Blaugrund (19) by an alteration of the ciliary activity secondary to a modified air flow. Bachert (24) demonstrates a connection between septal deviation and antral ventilation. CONCLUSION: This literature review cannot establish a definite role to the nasal septum neither as the pathogenesis of chronic sinusitis nor as a contributing factor. No relationship between septal surgery combined with sinus surgery, and the postoperative prognosis nor on the subjective comfort of patients can be demonstrated. Subsequently, it appears that performing septoplasty only aims at relieving nasal obstruction complaint or at improving surgical access to the ethmoïd sinus.

Adult↗