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Biomedical subjects

G Dumas

Publications and source records attributed to G Dumas.

At least 55 records · Page 3Linked to original sources
PubMed1991

Atrophic rhinitis caused by Pasteurella multocida type D: morphometric analysis.

In order to study the distribution and the extent of atrophy caused by Pasteurella multocida in the nasal conchae, experimental piglets were injected intramuscularly at seven days of age with either two or four 50% mouse lethal doses per kg body weight of P. multocida type D dermonecrotoxin. Experimental and control piglets were killed four, six and ten days postinjection. Serial transverse paraffin embedded sections of the noses were cut throughout the entire length of the nasal conchae. The area of the nasal ventral conchae was measured and the morphometric index of the nasal cavity was calculated. It was observed that P. multocida type D dermonecrotoxin induced severe atrophy of the nasal ventral conchae. This atrophy was present along the entire conchae. However, it was most severe at the level of the first and second premolar teeth.

Animals↗
PubMed1991

[Malformations of the bony labyrinth and deafness].

17 new cases of malformation of the bony labyrinth detected radiologically (tomography, CT) and associated with perceptive or composite deafness are reported. 2 cases discovered in spontaneous or traumatic recurrent meningitis are described, as well as 1 case discovered after the occurrence of total deafness following stapedial surgery. The malformations were unilateral in 7 cases, bilateral in 10. Deafness was of the composite type in 6 cases. An associated malformation of the middle or external ear was noted in 4 cases. 5 cases were included in a context of multiple malformations, including 1 case of otobranchiorenal syndrome, 1 case of Apert's syndrome and 3 cases of craniostenosis. Referring to the classification given by Mrs Vignaud and Jardin, we have encountered 1 case of stage I malformation, 9 cases of stage II, pseudo-Mondini malformation, 1 case of stage III or true Mondini malformation, 1 case of stage IV malformation, 3 cases of malformation of the aqueduct of the vestibule, ie. stage V. We have also encountered 2 isolate cases of stenosis of the internal auditory canal. On the basis of these cases, we report a few physiopathogenetic hypotheses and various classifications currently described in the literature. We also list the various associated external and middle ear malformations and the multiple-malformation syndromes that are commonly described. Stress is laid on the fact that these malformations often go undetected in congenital deafness, as well as on the usual course of these types of deafness for which there is no medical or surgical treatment.

Abnormalities, Multiple↗
PubMed1988

[Contribution of oculography and magnetic resonance imaging to the clinico-topographic correlates in ischemic vascular disorders of the brainstem].

6 patients with brainstem infarction and oculomotor signs were studied. One case was consistent with a mesencephalic infarct (internuclear ophthalmoplegia); 4 cases were consistent with a protuberantial infarct (3 cases of "one and a half" syndrome and one case of pontine reticular syndrome associated with a palsy of the root of the VIth nerve. One case was a laterobulbar syndrome. These 6 patients were studied with CT scan and magnetic resonance imaging (MRI CGR Magniscan 5000 with supraconductor magnet of 0.5 Tesla) with T2 weighted images (TR = 2000 ms, TE = 60; 120 ms) in joined section of 9 or 6 mm thickness. The MRI findings were in each case consistent with an infarction. The clinico-topographic correlations are compared with the oculographic findings.

Brain Ischemia↗
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

[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↗
PubMed1980

[Laryngotracheal stenosis treated by the Rethi operation : anatomical and functional (respiratory and vocal) results (author's transl].

On the basis of 25 cases of laryngotracheal stenosis of mescellaneous etiology, the authors report their experience of Rethi's operation carried out in 14 cases, 8 patients having received medical and instrumental treatment, 1 undergoing surgery for resection and anastomosis according to Pearson's technique and 3 receiving symptomatic treatment by tracheotomy because of inoperable stenosis. The frequency of postop-operative complications of Rethi's operation was analysed (essentially infectious, but also as a result of obstruction of the calibration prosthesis which represents a definite vial risk). Functional results were also assessed, being relatively satisfactory from a respiratory functional standpoint, but less good from a phonetic standpoint. The authors then define their present therapeutic attidude which leans, in the case of pure sub-glottal and sub-glotto-tracheal stenosis, towards a direct approach with resection anatomosis according to Pearson's technique rather than calibration procedures which remain the treatment ofa choice for glotto-sub-glottal stenosis.

Adolescent↗