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Biomedical subjects

D Robert

Publications and source records attributed to D Robert.

At least 109 records · Page 6Linked to original sources
PubMed1994

The tympanal hearing organ of the parasitoid fly Ormia ochracea (Diptera, Tachinidae, Ormiini).

Tympanate hearing has evolved in at least 6 different orders of insects, but had not been reported until recently in the Diptera. This study presents a newly discovered tympanal hearing organ, in the parasitoid tachinid fly, Ormia ochracea. The hearing organ is described in terms of external and internal morphology, cellular organization of the sensory organ and preliminary neuroanatomy of the primary auditory afferents. The ear is located on the frontal face of the prothorax, directly behind the head capsule. Conspicuously visible are a pair of thin cuticular membranes specialized for audition, the prosternal tympanal membranes. Directly attached to these membranes, within the enlarged prosternal chamber, are a pair of auditory sensory organs, the bulbae acusticae. These sensory organs are unique among all auditory organs known so far because both are contained within an unpartitioned acoustic chamber. The prosternal chamber is connected to the outside by a pair of tracheae. The cellular anatomy of the fly's scolopophorous organ was investigated by light and electron microscopy. The bulba acustica is a typical chordotonal organ and it contains approximately 70 receptor cells. It is similar to other insect sensory organs associated with tympanal ears. The similarity of the cellular organization and tympanal morphology of the ormiine ear to the ears of other tympanate insects suggests that there are potent constraints in the design features of tympanal hearing organs, which must function to detect high frequency auditory signals over long distances. Each sensory organ is innervated by a branch of the frontal nerve of the fused thoracic ganglia. The primary auditory afferents project to each of the pro-, meso-, and metathoracic neuropils. The fly's hearing organ is sexually dimorphic, whereby the tympanal membranes are larger in females and the spiracles larger in males. The dimorphism presumably reflects differences in the acoustic behavior in the two sexes.

Animals↗
PubMed1994

Nasal intermittent positive pressure ventilation. Long-term follow-up in patients with severe chronic respiratory insufficiency.

Prior studies have shown that nasal intermittent positive pressure ventilation (NIPPV) can improve arterial blood gas values, prevent symptoms resulting from alveolar hypoventilation, and decrease hospitalization in patients with chronic respiratory failure. Most studies have involved small samples of patients followed up for a limited time. This study reviews our experience during 5 years use of NIPPV in 276 patients with kyphoscoliosis, posttuberculosis sequelae, Duchenne-type muscular dystrophy, COPD, and bronchiectasis followed up for > or = 3 years while receiving NIPPV. Outcomes were compared for patients who survived short term eg, died or converted to management with a tracheostomy and intermittent positive ventilation (TIPPV) during year 1 or year 2 on a regimen of NIPPV and long term, eg, survived more > or = 2 years on a regimen of NIPPV. The most favorable outcome was achieved by patients with kyphoscoliosis and posttuberculosis sequelae with improvement in PaO2 and PaCO2 (p < 0.0001) and a reduction in days of hospitalization for respiratory illness (p < 0.0001) for > or = 2 years while receiving NIPPV. Patients with Duchenne-type muscular dystrophy also had fewer hospital days during NIPPV (p < 0.003) but only 9 of 16 patients (56 percent) continued using NIPPV for the duration of followup. Benefit was also more short term for patients with COPD and bronchiectasis. NIPPV can sustain improvement in gas exchange, while reducing hospitalization for substantial periods of time. NIPPV can be an attractive and effective alternative to other methods of assisted ventilation such as TIPPV.

Adult↗
PubMed1993

Sleep apnea syndrome and end-stage renal disease. Cure after renal transplantation.

We report two patients undergoing maintenance hemodialysis who presented with sleep apnea syndrome (SAS). The first patient is a 36-year-old man with a terminal Berger's glomerulopathy and associated obstructive sleep apnea syndrome (OSAS) (apnea-hypopnea index [AHI] = 80). He was receiving home hemodialysis and was treated by nasal continuous positive airway pressure (CPAP). After successful renal transplantation, his symptoms completely disappeared, and control polysomnography greatly improved (AHI = 9). The second patient had hypokalemic nephropathy with severe, uncontrolled hypertension and hypertensive myocardiopathy. He was receiving home dialysis and showed a central sleep apnea syndrome with an AHI of 51. He also was successfully treated by nasal CPAP. After renal transplantation, his sleep improved, insomnia disappeared, and polysomnography showed great improvement (AHI = 5). We discuss the role of periodic breathing related to end-stage renal disease associated metabolic abnormalities, as a pathogenetic factor of these SASs. Respiratory correction of chronic metabolic acidosis, "uremic toxins," "middle molecules," and hemodialysis are all evoked as etiologic factors and their own roles are discussed.

Adult↗
PubMed1993

[Nodules and paranodular lesions: a trial of anatomo-clinical correlation].

The use of increasingly powerful diagnostic tools has enabled the laryngologist to refine the diagnosis of nodular lesions, and, within this group, to isolate clinical variations, paranodular lesions, mucosal thickening, mucosal pseudo-cysts. Systematic comparison between the clinical and anatomopathological diagnosis of the lesions operated upon does not make it possible to establish a strict correlation between the clinical and the histological aspects. Nevertheless, histology appears to throw light on the physiopathology of such lesions within the field of dysfunctional laryngopathies.

Fiber Optic Technology↗
PubMed1993

[Multiparameter analysis of dysphonia using the equipment Physiologia].

The purpose of the multiparametric analysis of the vocal phenomenon is to evidence the instability of the signal in amplitude and in frequency, together with the aerodynamic phenomena related to the glottic air leakage. Statistical analysis has made it possible to establish a correlation between the data of the apparatus, as from 9 variables, and the clinical classification. The main diagnostic categories are relatively close, evidencing the various biomechanical anomalies of the laryngeal vibrator. A certain number of issues remain to be addressed: the physiopathology of the vibrator, the choice of the phonetic sample, and the different methods of instrumental analysis.

Biomechanical Phenomena↗
PubMed1993

[Launois-Bensaude disease and sleep apnea syndromes. Apropos of a recent case].

About a recent case of Launois-Bensaude's disease (Madelung's disease) the authors discuss the possibility of complications such as bronchopathy and sleep apnoea syndrome. General anaesthetics have to be performed with care, the anaesthetic risk exists even so during the premedication. Such patients have to be explored before the general anaesthetics by sleep polysomnography.

Humans↗
PubMed1993

[Chronic respiratory insufficiency. Non-invasive long-term ventilation methods].

The techniques of non-invasive ventilation have reappeared in force as an assortment of therapeutic techniques since the end of the 1980's. At the same time there was a transient renewed interest in perithoracic ventilation favouring the use of new methods of connection to the patient (e.g. poncho). The principal feature has been the use of intermittent positive pressure ventilation by the nasal route, which rapidly became essential for home therapy in patients with chronic restrictive respiratory failure notably in those secondary to thoracic deformation and to neuromuscular pathology. The concept of resting the respiratory muscles has been the basis for techniques of ventilatory assistance and in part the nasal route has now replaced home ventilation using a tracheotomy. Also in certain types of acute respiratory failure, nasal ventilation widely preferred over endotracheal ventilation.

Chronic Disease↗
PubMed1993

Long-term nasal ventilation in neuromuscular disorders: report of a consensus conference.

Following the colloquium entitled "Nasal Ventilation and Neuromuscular Disease", which took place in Lyon, France, October 24, 1991, a group of authorities on neuromuscular disorders met to establish a consensus concerning the application of this technique, in the clinical setting, for patients with Duchenne's muscular dystrophy, non-Duchenne myopathies and the spinal muscular atrophies. This report summarizes recommendations issuing from this conference. The conclusions drawn from this work should not be applied to patients with other diagnoses.

Humans↗
PubMed1992

The evolutionary convergence of hearing in a parasitoid fly and its cricket host.

Parasitism is a widespread and diverse life strategy that connects species throughout the animal kingdom. Female parasitoid flies of the genus Ormia must find a specific cricket host on which to deposit their parasitic maggots. To reproduce, female flies must perform the same task as female crickets: find a singing male cricket. These flies have evolved a unique hearing organ that allows them to detect and locate singing male crickets. Through evolutionary convergence, these flies possess a hearing organ that much more resembles a cricket's ear than a typical fly's ear, allowing these parasitoids to take advantage of the sensory ecological niche of their host.

Acoustic Stimulation↗