Etude de la symbiose Rhizobium-legumineuse: Préparation de cellules isolées pour l'étudein vitro

Résumé En vue d'une étude, au laboratoire, de la nodulation et de la symbiose plante-bactérie des préparations de protoplastes de mésophylle et de nodule racinaire ont été effectuées chez le haricot (Phaseolus vulgaris variété Constant). Pour chaque préparation, les conditions opératoires et les concentrations optimales de cellulase et de pectinase en solution, dans du mannitol 0,6M ont été définies.Áprès 15 jours, 10 à 15% des protoplastes de mésophylle mis en culture dans le milieu B5 de Gamborg se divisent 2 à 3 fois. Des essais de fusion réalisés avec des faibles densités cellulaires entre protoplastes de mésophylle et protoplastes de nodule ont, donné des taux de fusion de l'ordre de 2,43%.

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Study of the symbiosis Rhizobium-legume: Preparation of isolated cells forin vitro study

Summary With a view to studyin vitro the processes of nodulation and plant-bacteria symbiosis, preparation of mesophyll protoplasts and root nodule protoplasts have been realized fromPhaseolus vulgaris (Constant var.).For every preparation the process of experimentation and optimum concentrations of cellulase and pectinase diluted in mannitol 0,6M have been defined.After a 15 days' period, 10 to 15% of mesophyll protoplasts divided twice or even three times in B5 Gamborg's medium. Although we used low rate cell concentrations, root nodule protoplasts and mesophyll protoplasts have been able to fuse in the proportion of 2,43%.

     

Méthode simple pour la dessiccation dans le vide de cultures bactériennes

Sommaire Dessication dans le vide de cultures bactériennes, par procédé simple et rapide.     

La genre Scinaia (Rhodophycées,Nemalionales) de la Méditerranée occidentale

Abstract

The genus Scinaia (Rhodopbyta. Nemalionales) of the western Mediterranean sea. Only 3 species of Scinaia are to be found in Western Mediterranean sea. Scinaia complanala, S. furcellata and S. turgida. Scinaia sanctaluciana Funk is considered as a juvenile thallus of Scinaia complanala. Scinaia turgida is recorded for the first time in the Tyrrhenian sea since MAZZA (1902, 1903). A new anatomical character for the distinction of the Scinaia complanala and Scinaia turgida is also given.     

Utilité de la TEP au 18FDG dans l’épilepsie. Méthodes et indications

Positron emission tomography (PET) using ¹⁸fluorodeoxyglucose (¹⁸FDG) is currently used in presurgical work-up for drug-resistant partial epilepsies in children as in adults, in addition to MRI. Recent cameras with less than 5 mm spatial resolution allow to obtain thin slices (about 2 mm thickness) in 3D planes. ¹⁸FDG is intravenously injected at the mean dose of 3 MBq/kg of body weight in interictal and resting state, in a quiet, dimly lit environment and careful monitoring for head movements and ictal events. In children, sedation may be necessary. Image acquisition starts 30 min after injection and ended 15 to 20 min later. Semiquantitative analysis is visually assessed in clinical practice using colour scales. PET sensibility is improved by superimposition of metabolic imaging on MRI. Statistical analysis with SPM may be useful but comparison with health subjects database is required. In medial temporal lobe epilepsy associated with hippocampal sclerosis, hypometabolism ipsilateral to the epileptogenic focus is found in 70 to 90% of the cases and is predictive of surgical outcome. In other types of temporal and extratemporal epilepsy with negative MRI, focal hypometabolism can be detected, allowing identification of minor gyral abnormalities corresponding to focal cortical dysplasias. In such MRI negative cases, PET findings may improve surgical outcome.