In Silico and Biochemical Analysis of Physcomitrella patens Photosynthetic Antenna: Identification of Subunits which Evolved upon Land Adaptation

Background. In eukaryotes the photosynthetic antenna system is composed of subunits encoded by the light harvesting complex (Lhc) multigene family. These proteins play a key role in photosynthesis and are involved in both light harvesting and photoprotection. The moss Physcomitrella patens is a member of a lineage that diverged from seed plants early after land colonization and therefore by studying this organism, we may gain insight into adaptations to the aerial environment. Principal Findings. In this study, we characterized the antenna protein multigene family in Physcomitrella patens, by sequence analysis as well as biochemical and functional investigations. Sequence identification and analysis showed that some antenna polypeptides, such as Lhcb3 and Lhcb6, are present only in land organisms, suggesting they play a role in adaptation to the sub-aerial environment. Our functional analysis which showed that photo-protective mechanisms in Physcomitrella patens are very similar to those in seed plants fits with this hypothesis. In particular, Physcomitrella patens also activates Non Photochemical Quenching upon illumination, consistent with the detection of an ortholog of the PsbS protein. As a further adaptation to terrestrial conditions, the content of Photosystem I low energy absorbing chlorophylls also increased, as demonstrated by differences in Lhca3 and Lhca4 polypeptide sequences, in vitro reconstitution experiments and low temperature fluorescence spectra. Conclusions. This study highlights the role of Lhc family members in environmental adaptation and allowed proteins associated with mechanisms of stress resistance to be identified within this large family

Bon usage des antibiotiques (évaluation de l'index d'adéquation thérapeutique des pyélonéphrites aiguës après mise en place d'un référentiel)

BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Analyse des causes de fièvre à plus de 48 heures d'une antibiothérapie instaurée en ambulatoire chez des patients admis aux urgences (à propos d'une série de cas étudiés entre novembre 2001 et mai 2002 au centre hospitalier intercommunal de Cornouaille dans le Finistère)

BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Analyse de la prise en charge des pyélonéphrites aiguës aux urgences du CH de Quimper après mise en place d'un référentiel

BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Qualité des antibiothérapies prescrites aux patients non hospitalisés par le service des urgences du centre hospitalier de Quimper

Le niveau des consommations ambulatoires en antibiotiques est corrélé au développement de bactéries de sensibilités diminuées à l'échelon individuel et de la collectivité. En utilisant l'algorithme décisionnel de Gyssens, nous avons évalué les antibiothérapies prescrites par le service des urgences du centre hospitalier de Quimper (Finistère) aux patients non hospitalisés. Cette étude rétrospective sur une période de trois mois (novembre 2007 à janvier 2008) a inclus 177 patients. Seules 10,2% des prescriptions étaient en accord avec les recommandations. Un référentiel d'aide à la prescription, basé sur les recommandations et traitant des situations les plus fréquemment rencontrées a été élaboré.BREST-BU Médecine-Odontologie (290192102) / SudocSudocFranceF

Comparison of the Respiratory Toxicity and Total Cholinesterase Activities in Dimethyl Versus Diethyl Paraoxon-Poisoned Rats

The chemical structure of organophosphate compounds (OPs) is a well-known factor which modifies the acute toxicity of these compounds. We compared ventilation at rest and cholinesterase activities in male Sprague-Dawley rats poisoned with dimethyl paraoxon (DMPO) and diethyl paraoxon (DEPO) at a subcutaneous dose corresponding to 50% of the median lethal dose (MLD). Ventilation at rest was recorded by whole body plethysmography. Total cholinesterase activities were determined by radiometric assay. Both organophosphates decreased significantly the respiratory rate, resulting from an increase in expiratory time. Dimethyl-induced respiratory toxicity spontaneously reversed within 120 min post-injection. Diethyl-induced respiratory toxicity was long-lasting, more than 180 min post-injection. Both organophosphates decreased cholinesterase activities from 10 to 180 min post-injection with the same degree of inhibition of total cholinesterase within an onset at the same times after injection. There were no significant differences in residual cholinesterase activities between dimethyl and diethyl paraoxon groups at any time. The structure of the alkoxy-group is a determinant factor of the late phase of poisoning, conditioning duration of toxicity without significant effects on the magnitude of alteration of respiratory parameters. For same duration and magnitude of cholinesterase inhibition, there was a strong discrepancy in the time-course of effects between the two compounds.</jats:p

Comparison of the Respiratory Toxicity and Total Cholinesterase Activities in Dimethyl Versus Diethyl Paraoxon-Poisoned Rats

The chemical structure of organophosphate compounds (OPs) is a well-known factor which modifies the acute toxicity of these compounds. We compared ventilation at rest and cholinesterase activities in male Sprague-Dawley rats poisoned with dimethyl paraoxon (DMPO) and diethyl paraoxon (DEPO) at a subcutaneous dose corresponding to 50% of the median lethal dose (MLD). Ventilation at rest was recorded by whole body plethysmography. Total cholinesterase activities were determined by radiometric assay. Both organophosphates decreased significantly the respiratory rate, resulting from an increase in expiratory time. Dimethyl-induced respiratory toxicity spontaneously reversed within 120 min post-injection. Diethyl-induced respiratory toxicity was long-lasting, more than 180 min post-injection. Both organophosphates decreased cholinesterase activities from 10 to 180 min post-injection with the same degree of inhibition of total cholinesterase within an onset at the same times after injection. There were no significant differences in residual cholinesterase activities between dimethyl and diethyl paraoxon groups at any time. The structure of the alkoxy-group is a determinant factor of the late phase of poisoning, conditioning duration of toxicity without significant effects on the magnitude of alteration of respiratory parameters. For same duration and magnitude of cholinesterase inhibition, there was a strong discrepancy in the time-course of effects between the two compounds

Mononeuritis multiplex in a patient with B-cell prolymphocytic leukaemia: a diagnostic challenge.

International audienceB-cell prolymphocytic leukaemia (BPLL) is a haematological malignancy defined as lymphocytosis and splenomegaly with >55% circulating cells being clonal prolymphocytes of B-cell origin. The evolution of this disease is more aggressive than chronic lymphocytic leukaemia. We reported a case of a 62-year-old man with BPLL who, on treatment, attained cytological, immunophenotypic and complete cytogenetic remission. He subsequently developed an asymmetric sensorimotor neurological disorder, suggestive of lymphomatous infiltration (neurolymphocytosis). Repetition of the MRI and the electromyography was essential for diagnosis. Progressive mononeuritis multiplex in B-cell leukaemias/lymphomas is rare and may be the only presenting symptom of relapsed or progressive disease. Repeat imaging studies based on judicious evaluation of the clinical scenario for exclusion of other causes of neurological symptoms is necessary. This can be challenging in patients with long-standing malignancies who have received multiple courses of chemotherapy and/or radiotherapy