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Biomedical subjects

J Achouche

Publications and source records attributed to J Achouche.

6 recordsLinked to original sources
PubMed1992

[Intra- and extracranial nasopharyngeal fibroma. Contribution of imaging and study of local failure. Report on 34 patients].

Thirty-four patients with nasopharyngeal angiofibroma were treated between 1975 and 1990. Lesions were classed according to Sessions' classification. 17 showed intracranial extension. Treatment always associated embolization and surgical excision using a transfacial approach and, if necessary, neurosurgical techniques. A total of 13 patients (38.2%) developed recurrent lesions; these included 3 (17.6%) patients in the extracranial group and 10 (58.8%) patients in the intracranial group. Erosion of the clivus and displacement of the cavernous sinus seem to be 2 factors significantly associated with the development of recurrent lesions. Symptomatic recurrences were managed by surgery. Close clinical and radiological follow-up of patients with asymptomatic recurrent tumor made it possible to observe the stabilization, or even, the regression of the tumor. This study also underlines the importance of modern diagnostic and interventional imaging, which makes it possible to better determine tumor extension and to perform highly selective embolizations. Modern imaging also detects recurrences which once would have remained unknown because of their small size and the absence of symptoms. The techniques of embolization of the tumor branches from the internal and external carotid arteries are explained. Finally, our results are compared to those published in the literature.

Adolescent↗
PubMed1991

Primary culture of strial marginal cells of guinea pig cochlea: growth, morphologic features, and characterization.

To further investigate the cellular mechanisms involved in the formation of endolymph, primary cultures of marginal cells of guinea pig were established. Minute explants obtained by mechanical dissociation of stria vascularis were plated on collagen type I precoated impermeable substrate in serum-free, hormone-supplemented medium. A confluent layer of epithelial-like cells was obtained within 2 weeks. The cultured cells formed domes, demonstrating that they retain some of their transepithelial properties. Polarization was also suggested by electron microscopic observation of apical microvilli and tight junctions. Immunohistochemical methods revealed that the cultured cells coexpressed cytokeratin and vimentin, demonstrating their epithelial origin, although some degree of dedifferentiation occurred. Thus, a primary culture of marginal cells can be established that may be a suitable model for an in-depth investigation of the function of the marginal cells.

Animals↗
PubMed1991

Luminal non-specific cationic channels in cultured strial marginal cells of guinea pig and gerbil as determined by patch clamp technique.

Using primary cultures of marginal cells of stria vascularis from guinea pig and gerbil, ionic channels located on the luminal membrane were investigated by means of patch clamp technique. Recordings were performed in cell-attached and inside-out configurations. In cell-attached configuration, single channel activity was identified with a conductance of about 25 pS. I-V curve was linear. The probability of opening was increased upon depolarization. Up to 7 channels could be present in the same patch, indicating a rather high density. In inside-out configuration, the reversal potential was 0 mV, suggesting a non-specific cationic channel. These luminal non-specific cationic channels would allow the passive K+ efflux and Na+ influx across the apical membrane of marginal cells. This finding is consistent with the "one-pump" model of strial activity. The present study suggests that culture of strial marginal cells may be a suitable model for in-depth investigation of endolymph physiology.

Animals↗
PubMed1991

[Diagnostic strategy of acoustic neuroma. Evaluation of efficacy of auditory evoked potentials. Apropos of a series of 50 neuroma cases].

The authors carry out a retrospective study of the diagnostic procedures used in a series of 50 acoustic neuromas. AEP were performed for thirty-four neuromas at some stage of their history. The findings were perfectly normal for eight of them, which represents a sensitivity level of 76%. Various elements likely to account for this are put forward, then the role of AEP and MRI in the diagnostic strategy for neuroma is discussed in the light of this study. Finally, the authors emphasize the necessity to regularly evaluate the diagnostic methods in order to guarantee their quality and reliability.

Evoked Potentials, Auditory↗
PubMed1991

[Malignant external otitis. When and which imaging].

Malignant external otitis (MEO) is a severe infection of the external auditory canal (EAC), most often caused by Pseudomonas aeruginosa, although a few cases are caused by an Aspergillus (4). Mortality remains high (20%) in spite of an early general antibiotic treatment. This infection of the soft tissue of the EAC causes cellulitis, chondritis and osteomyelitis, and there are risks of diffusion into the base of the skull. Our work is aimed at placing computed tomography and magnetic resonance imaging into the context of exploration of this infection, in relation to radionuclide scanning, owing to our experience with 10 patients. Imaging appreciates the anatomical extension of the infection beyond the EAC and towards the base of the skull and the infratemporal fossa, this being a key element for prognosis. It assesses the efficiency and duration of treatment, although the criteria of healing are still difficult to appreciate and late recurrence is frequent. Exceptionally, it is useful for diagnosis in some particular clinical forms.

Adult↗