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Biomedical subjects

N Julien

Publications and source records attributed to N Julien.

At least 37 records · Page 2Linked to original sources
PubMed1994

Antidiuretic hormone restores the endolymphatic longitudinal K+ gradient in the Brattleboro rat cochlea.

In the cochlea, endolymph is hyperosmotic to plasma and perilymph. To test the hypothesis that antidiuretic hormone is involved in the modulation of endolymph secretion, the electrochemical composition of cochlear fluids, endolymph and perilymph, was studied in three groups of anaesthetized rats: control Long Evans rats, homozygous Brattleboro rats that are genetically deprived of antidiuretic hormone, and Brattleboro rats that were treated with antidiuretic hormone (dDAVP, 0.5 microgram/100 g body weight/24 h during 8 days). Endolymph was sampled from the scala media at each turn of the cochlea and perilymph from the scala vestibuli. In Long Evans rats, the endocochlear potential, the endolymphatic K+ and Cl- concentrations decreased from base to apex of the cochlea as previously reported in guinea pigs and Sprague Dawley rats. In Brattleboro rats, the endocochlear potential and the Cl- concentration gradients were still present, whereas the K+ concentration gradient were still present, whereas the K+ concentration gradient was absent. This K+ gradient was restored by the administration of dDAVP, which increased the K+ concentration at the base of the cochlea. This work indicates that the K+ secretion in endolymph, and thus the osmolality, may be locally modulated by the antidiuretic hormone, probably via V2 receptors.

Animals↗
PubMed1994

[Melanoma in children: a case].

INTRODUCTION: Melanoma is rare in children. We report a new case. CASE REPORT: A black tumor on the medial aspect of the right thigh was removed at the age of 5 years. Histologic diagnosis was melanoma. One year later, a metastasic inguinal lymph node appeared in the right inguinal fold. Exeresis with curetage was performed followed with chemotherapy. Outcome has been favourable to date. DISCUSSION: The diagnosis of melanoma is difficult in children and is usually mistaken. In this case, the histologic diagnosis appears to have been exact and chemotherapy was performed. The rationale and modalities have been discussed.

Age Factors↗
PubMed1993

Is the endolymphatic K secretion electrogenic?

The endolymphatic potential is assumed to result from active K transport into the endolymphatic compartment and passive K diffusion in the opposite direction. However, in several in vivo experiments, changes in the endolymphatic potential differed from those in the endolymphatic K concentration. Moreover, in in vitro experiments, a negative endolymphatic potential was observed in the presence of ouabain without K gradient between the two compartments. These observations suggest that the coupling between the K transport and the genesis of the endolymphatic potential is not tight. Several factors may separately influence the endolymphatic potential and the K transport such as the acid-base equilibrium, the integrity of Reissner's membrane, the hormonal status, and the Na transport.

Animals↗
PubMed1993

[Jugular bulb diverticulum mimicking Menière's disease. Surgical treatment].

The position of the jugular bulb is extremely variable. A high jugular fossa with a diverticulum of the jugular bulb can alter the inner ear function with neurosensory hearing loss, vertigo and tinnitus. Six cases of jugular bulb diverticulum with vertigo mimicking Meniere's disease were operated on and followed up from 6 months to 4 years. The jugular bulb was approached through a mastoidectomy and the diverticulum was decompressed downward using bone wax. The vertigo disappeared after surgery in all the cases. These observations suggest that an abnormality of the jugular bulb should be considered as a possible origin of Meniere's disease and that vertigo can be cured by downward decompression of the diverticulum.

Adult↗
PubMed1993

[Pleomorphic adenoma of the nasal septum. Apropos of a case].

Pleomorphic adenoma is the common benign tumor of glandular tissue occurring in the head neck region. The authors report a case localised in the nasal septum, which is an uncommon site for this tumor. Symptoms include unilateral nasal obstruction and intermittent nasal bleeding. Local surgical resection with histologic clear margins is the treatment of choice but long term follow-up is recommended.

Adenoma, Pleomorphic↗
PubMed1993

[Mechanisms of electrogenic secretion of potassium in endolymph].

Endolymphatic potential is assumed to result from active K transport into the endolymphatic compartment and passive K diffusion in the opposite direction. However, in several in vivo experiments, changes in endolymphatic potential differed from that in endolymphatic K concentration. Moreover, in in vitro experiments, a negative endolymphatic potential was observed in presence of ouabain without K gradient between the two compartments. These observations suggest that the coupling between the K transport and the genesis of the endolymphatic potential is not tight. Several factors may influence separately the endolymphatic potential and the K transport such as the acid-base equilibrium, the integrity of the Reissner's membrane, the hormonal status and the Na transport.

Endolymph↗
PubMed1993

[Lingual rhabdomyosarcoma in an adult patient].

A case of rhabdomyosarcoma of the tongue in an adult male is reported. The diagnosis of this rare lesion is difficult and should be considered in every growing mass of the head and neck region. It is based on the pathologic examination of tissue samples guided by immunohistological methods. In this case the examination revealed an embryonal type. The tumoral progression is rapidly fatal unless an aggressive therapeutic regimen including surgery and radiotherapy is instituted. In this manner dramatic improvement in survival rate has been achieved in recent years.

Adult↗
PubMed1993

[Bacterial epidemiology of chronic otitis. Prophylactic and therapeutic deductions].

Antimicrobial sampling was performed in the external auditory canal and in the mastoid cavity when possible in 80 middle ears operated on during the last 15 months. These samplings concerned 20 cholesteatomas. 25 suppurative chronic otitis, 25 non suppurative chronic otitis and 6 miscellaneous. In 20 out of 80 cases (25%), one or several microbial agents were identified: cholesteatomas (35%), suppurative chronic otitis (38%), non suppurative ones (4%) and miscellaneous (16%). In most cases a staphylococcus or a negative gram agent was sensitive to amoxycillin-clavulanique acid. When sampling was performed in the mastoid cavity, the agent was not sensitive to this antibiotic (80% of cases). This study demonstrates that a prophylactic therapy against aerobic and anaerobic agents is necessary in non suppurative chronic otitis whereas the antimicrobial therapy must be adapted in other pathologies.

Adolescent↗
PubMed1992

Postlaryngectomy voice restoration. A prospective study in 83 patients.

From July 1985 until May 1990, 83 patients underwent a total laryngectomy. We prospectively studied voice restoration in 81 of them (two died postoperatively). Esophageal voice was used by 19 patients; a tracheoesophageal procedure (myomucosal shunt, primary or secondary puncture with Blom-Singer prosthesis) by 41; and 21 patients had no voice restoration. Results were assessed according to voice quality and usage. Tracheoesophageal speech had a success rate of 73% (good voice, daily use) after 1 month, while esophageal voice proved to have only a 5% success rate. Thirty patients (37%), however, remained without a substitute voice. The reasons for their exclusion are presented; they include a high rate of refusal.

Adult↗
PubMed1992

[Hemangioma of the petrous bone. Diagnosis and treatment].

Hemangiomas of the temporal bone are benign, vascular and are tumors. The diagnosis is in most cases made during the operation because the symptoms are non conclusive. Two cases were recently observed: one simulating a Meniere disease while the tumor was developed close to the jugular bulb and the endolymphatic sac; the second invaded the geniculate area and the petrous apex and was revealed by a progressive facial palsy.

Facial Paralysis↗
PubMed1991

[Infratemporal extension of tumors of the skull base].

The tumors of the middle and posterior portion of the skull base may extend extracranially. The spread of the tumors towards the infratemporal fossa is rare. Among 23 skull base tumors with extracranial extension which were diagnosed during the last 5 years, only two middle ear epidermoid carcinomas extended into the infratemporal fossa. Subtotal surgical removal of tumors was obtained in both cases through a subtotal petrectomy with an ultrasonic aspiration of the extracranial extension followed by transcutaneous irradiation. One case is followed free of disease 2 years and a half after the beginning of the treatment. The spread of the tumor into the infratemporal fossa might not be of poor prognosis.

Aged↗
PubMed1991

[Contribution of magnetic resonance imaging in the evaluation of chronic otitis].

Thirty four patients with a chronic otitis were evaluated prospectively by magnetic resonance imaging (MRI) to delineate its contribution in the diagnosis of middle ear masses. The results were correlated to the CT and the surgical and pathological findings. MRI permitted to differentiate the inflammatory tissues from either cholesteatoma, cholesterol granuloma and cerebromeningeal hernia.

Chronic Disease↗
PubMed1991

[Meningocerebral hernia and defects of the tegmen. Diagnosis and surgical treatment].

Eight defects of the tegmen tympani or antri have been operated on during the last two years. Among these cases, 4 brain herniae were associated with the defect of the tegmen. Magnetic resonance imaging permitted to evaluate accurately the space occupying lesions into the mastoid cavity and disclosed the brain and/or meningeal herniations. The defect of the tegmen was oblitered through a middle fossa approach whereas the hernia was resected through a mastoid approach when necessary.

Adult↗
PubMed1991

[Vocal restoration by tracheo-esophageal fistula. Evaluation of a 5 years' experience].

Between december 1985 and august 1990, 70 patients with total laryngectomy had their voice restaured by creation of tracheo-esophageal fistula. The tracheo-esophageal fistula was created during laryngectomy in 33 cases (20 punctures with Blom Singer prostheses, 13 surgical shunts), a few weeks later after surgery of radiotherapy in 17 cases or when production of esophageal voice feld in 20 cases. No major complication was observed. Results following voice recovery were satisfactory in 78.5% of cases (normal voice), one month after the procedure. Results are better when tracheo-oesophageal fistula was used initially (88%), than performed secondary (55%). After one year, results were satisfactory in 75.5% of cases.

Esophagus↗
PubMed1989

Cholesterol granulomas of the middle ear cavities: MR imaging.

Symptomatic cholesterol granuloma developed in the middle ear cavities in three cases. At computed tomography (CT) after the administration of contrast material, the granulomas appeared as nonspecific, nonenhanced soft-tissue masses with variable bone erosion. These features are indistinguishable from those of other similar clinical entities, especially cholesteatoma, paraganglioma, and endaural brain hernia. At magnetic resonance (MR) imaging, cholesterol granulomas had a more characteristic appearance. In two cases, the granulomas were depicted as areas of high signal intensity with both T1- and T2-weighted sequences. In the third case, an expansile mastoid cholesterol cyst exhibited medium signal intensity on T1-weighted images, with only a small hyperintense area and a hypointense area located in the cystic wall. Correlations between CT, MR, and microscopic findings show that MR imaging is far superior to CT in tumoral characterization, which is crucial for planning surgical approaches. MR imaging has limitations, however, particularly its inability to depict subtle bone abnormalities.

Adult↗
PubMed1989

[Cholesterol granuloma of the middle ear. Apropos of 3 cases].

Cholesterol granulomas arise scarcely within the middle ear cavities revealed by a conductive deafness. They appear on the CT scan as a non specific mass developed in the middle ear cavities with bone defects. MRI allow the diagnosis as cholesterol granulomas is defined by hyperintensity on all sequences.

Adult↗