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Biomedical subjects

R Charachon

Publications and source records attributed to R Charachon.

At least 73 records · Page 4Linked to original sources
PubMed1982

[Electrophysiological study of the ototoxicity of kanamycin via transplacental transmission in the guinea pig (author's transl)].

Pregnant guinea pigs were treated with Kanamycin at three different times during gestation (dating by the post-partum ovulation method) : 11th-20th day, 31st-40th day, 53rd-62nd day of gestation. 29 newborn guinea pigs were studied electrophysiologically by the recording of cochlear microphonics and the action potential obtained at the fenestra cochlear in response to clicks and filtered clicks 8000. Certain animals were tested with filtered clicks 2000 and 4000. 6 tested animals showed electrophysiological results identical to those usually seen in adult guinea pigs intoxicated with Kanamycin. The results obtained suggest the existence of a relationship between the ototoxicity of Kanamycin and the time of installation of auditory function. Microphonic potentials and auditory nerve action potentials were found to be more affected when intoxication took place during the last 15 days of gestation.

Animals↗
PubMed1981

[Signal symptoms in tumours of the petrous bone (author's transl)].

Supra-labyrinthic tumours usually produce lesions of the Vth and VIth cranial nerves, whereas infra-labyrinthic tumours affect the sensory-motor nerves. Both types of tumour may reveal themselves by cochleo-vestibular disorders and/or middle ear symptoms. The author has treated a series of patients with such tumours and describes the most frequent types of intrapetrosal growth: cholesteatoma (12 cases), glomic tumours (11 cases), facial nerve tumours (3 cases), metastases (2 cases). Meningiomas can also be encountered, as well as rarer tumours (4 cases), such as embryonic sarcoma, chordoma, chondroma and chondrosarcoma, cavernous angioma, eosinophilic granuloma, solitary plasmocytoma and fibrous dysplasia of the petrous bone. Some signal symptoms (sudden deafness, mucous otitis media, paralysis of vocal cords) can be particularly misleading.

Adolescent↗
PubMed1981

[Kanamycin-induced lesions of the stria vascularis: preliminary results of an electrophysiological and ultrastructural study (author's transl)].

Ten guinea-pigs were treated with kanamycin 400 mg/kg for a 10-day period. Electrophysiological investigations were carried out, and the animals were killed one month after the end of the treatment for electron microscope study of the second turn of the cochlear spiral. The microphonic potential was considerably reduced, and the stria vascularis was the seat of lysosomal inclusions in the marginal and intermediate cells associated with myeloid bodies in the vascular endothelium. There was a gradient of lysosomal catabolic residues, probably lipoproteins, from the vascular sector to the cochlear canal; some of these products passed into the cochlear canal. Alterations of the hair cells in the second spire appeared to be minimal. It is hypothesized that damage to the stria vascularis precedes damage to the hair cells.

Animals↗
PubMed1981

[Uncommon tumors of the petrous bone. 4 cases (author's transl)].

Four cases of uncommon tumours of the petrous bone treated by surgery alone or combined with radiotherapy are reported. There was one case embryonic sarcoma in a 3-year-old female child and one case each of chondroid chordoma, isolated plasmocytoma and malignant fibroid chondrosarcoma or histiocytoma with giant cells. The signal symptoms (pseudo-petrositis, isolated paralysis of a vocal cord, sudden deafness) may be misleading. The most helpful diagnostic methods are frontal tomography and CT scanning.

Child, Preschool↗