Biomedical subjects
P Benoit
Publications and source records attributed to P Benoit.
[Existence of very weak level of residual multiple innervation of Purkinje cells through climbing fibers in the cerebellum of the normal adult rat].
Extra- or intracellular unit responses of Purkinje cells to the activation of climbing fibres were recorded in the cerebellum of adult rats. Out of 1.719 cels studied, only 4 were found to be innervated by more than one climbing fibre. This very small rate of residual multiple innervation in the normal adult illustrates the accuracy of the synaptic elimination process which leads to the innervation of each Purkinje cell through only one climbing fibre during normal development in the rat.
[Post-radiotherapy stenosis of the supraclinoid internal carotid artery. Moyamoya network].
A 36 year-old caucasian woman was operated and then irradiated for a pituitary adenoma. Two years later, a left anterior temporal lobectomy for a grade I astrocytoma was performed. Four years later, she experienced right hemiparesis and aphasia. CT scan showed a left temporo-occipital low density area. A left carotid angiogram showed a narrowing of the left carotid artery beginning in the lower part of the siphon and progressing to a complete supraclinoid occlusion. There was a collateral circulation of the Moyamoya type. Radiation-induced narrowing or occlusion of the intracranial internal carotid artery is an infrequent finding. Most cases appear in young subjects, several years after a high dose of radiation therapy (30 to 60 grays). Some cases may show a network of the Moyamoya type. Usually, the absence of vascular abnormalities prior to radiation cannot be demonstrated. In our case, as in 3 other cases of the literature, the intracranial vessels were of normal appearance before irradiation. The vascular lesions can thus be considered as acquired and secondary to radiation therapy.
Stability of multiple innervation of Purkinje cells by climbing fibers in the agranular cerebellum of old rats X-irradiated at birth.
In the cerebellum of old X-irradiated rats, the multiple innervation of Purkinje cells by climbing fibers, which normally regresses after birth, was still present up to 18 months. Furthermore, the mean number of synaptic contacts upon each Purkinje cell was not smaller than what is observed in young adults, indicating that, after irradiation, these redundant synapses are definitively stabilized.
[Brachial plexus paralysis caused by hematoma during anticoagulant treatment].
The authors describe a case of brachial plexus'lesion at axillary level in a patient under anticoagulation therapy. They underline the use of CT scan and digitalized angiography to establish the diagnosis and choice the treatment.
[Rare complication of extracorporeal circulation: diffuse coronary fibrosis; giant cell myocarditis].
A 38 year old woman developed severe coronary stenosis several months after double valve replacement. Aorto-coronary bypass surgery was performed but the patient died of a peroperative myocardial infarction. Histological studies showed not only fibrous thickening of the intima of the whole coronary arterial tree, but also variable medial changes with inflammatory infiltration. In addition, inflammatory granulomata with giant cells were found in the myocardium. These coronary lesions and their association with a giant cell myocarditis cannot be satisfactorily explained by known pathological conditions. The usual mechanisms of coronary disease were not operative in this case. There remains the hypothesis of a primary change of the coronary wall related to either cannulation, anoxic arrest or perfusion fluid, or a combination of these factors. The coronary lesions could have developed by an immunological process which would also explain the giant cell myocarditis.
[Uveitis and cerebral lymphoma].
A 57 year-old man developed a left posterior uveitis, without obvious aetiology and unresponsive to antibiotherapy and steroids. Nine months later, a lymphoma of the left parieto-occipital area was discovered. An immunological study detected a peripheral blood T lymphocytes deficiency, a B lymphocytes excess and a monoclonal gammopathy (IgM lambda). The latter abnormality disappeared one month after neurosurgery. Tumor cells were of the B lymphoid type with lambda light chain only. Brain irradiation and chemotherapy first improved neurological signs but right uveitis developed. The patient died 22 months after the first ophthalmological symptoms. The association of primary non Hodgkin brain lymphoma (PNHBL) (reticulum-cell sarcoma) with uveitis has already been described in 51 other cases in the literature. Two possibilities are considered: first, uveitis appears with or follows the neurological signs (NS): the prognosis is the same as that of PNHBL alone; second, uveitis appears before the NS: the prognosis is better and can be improved by brain and ocular irradiation. The immunological abnormalities are discussed. T lymphocytes deficiency and B lymphocytes excess have already been described but a monoclonal gammopathy is a more unusual finding.
[Radiotherapy of primary malignant tumors of the trachea. Apropos of 31 cases].
We report 31 cases of primary malignant tumours of the trachea, treated with radiotherapy at the Tumour Centre, Pitié-Salpêtrière, from June 1968 to January 1982. Three patients received complementary post-operative irradiation: one had an epidermoid carcinoma, operated by incomplete resection and anastomosis, and survived 12 months after irradiation with 60,00 grays in 6 weeks (local recurrence of tumour and mediastinal extension); the other two had cylindromas of the trachea with complete resection and anastomosis: the first remains alive 6 years after an irradiation of 65,00 grays over 6 weeks, the second is alive 5 years after post-operative irradiation of 60,00 grays in 6 weeks. These two latter tumours evolved slowly and local recurrence may occur after five years and sometimes longer, after local treatment. 28 other cases presenting with an epidermoid carcinoma of the trachea received radiotherapy exclusively, when a surgical cure was impossible. Irradiation was interrupted in two patients: one after a dose of 12,00 grays for sudden massive haemoptysis, the other after a dose of 22,00 grays for an oesophago-tracheal fistula. An apparent complete remission was obtained in 80% of cases, judged by a tracheo-bronchial endoscopic examination carried out in the six weeks following the treatment. Two deaths were seen from intercurrent disease: one at two months from a granulocytosis caused iatrogenically from medication and the other at five months from bilateral bronchopneumonia. One patient was alive at 9 months in apparent complete local remission, but lost to follow up.(ABSTRACT TRUNCATED AT 250 WORDS)
[3-dimensional photographic registration of mandibular movements].
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[Comparative study of the anti-inflammatory and analgesic action of sodium Naproxen and Indomethacin in the post-operative period of tooth extraction].
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[Acute lymphoblastic leukemia in children: therapeutic aspects].
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Amphotericin B induced alteration in membrane permeability: pH effects.
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[Sciatic paralysis during anticoagulant treatment].
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Effect of 1-methyl cyclohexane carboxylic acid on electrical activity of Purkinje cells in the rat: evidence for a potentiation of intracerebellar inhibition.
The effect of an anticonvulsant compound (Simiand, Ferrandes, Lacolle and Eymard, 1979), 1-methyl cyclohexane carboxylic acid (CCA), upon the electrical activity of Purkinje cells (PCs) was studied in the cerebellar cortex of the rat in vivo. Cyclohexane carboxylic acid (200-400 mg/kg i.v.) decreased the spontaneous simple spike (SS) activity of the Purkinje cells tested without modifying the complex spike (CS) frequency. Two effects of CCA upon intracortical inhibition were observed: (1) the decrease in firing rate that followed surface stimulation of the parallel fibres (LOC stimulation) was enhanced after injection of CCA; (2) the depression of the antidromic field potential of Purkinje cells by a conditioning stimulation was also enhanced after injection of CCA. This latter effect was suppressed in a reversible manner by injection of bicuculline. These results strongly suggest that the effect of CCA upon electrical activity of Purkinje cells is related to an enhancement of the inhibition exerted on Purkinje cells by GABAergic, cerebellar interneurones. The possible mechanisms of action of CCA are discussed.
[The place of lidocaine in the treatment of acute attacks of intracranial hypertension].
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