Faut-il mettre en isolement tous les patients qui bénéficient d’une recherche de tuberculose pulmonaire dans les services de médecine interne ?

National audienceIntroduction La tuberculose est une pathologie fréquente et grave dont le mode de transmission et la contagiosité facilitent sa transmission intrahospitalière. La recherche d’une tuberculose est une situation fréquente dans un service de médecine interne mais réalisée le plus souvent dans le but d’éliminer le diagnostic. Malgré tout, la prévention des cas secondaires passe par des mesures d’isolement respiratoire contraignantes et peu adaptées à certains services. L’objectif de cette étude était donc de faire le point dans un service de médecine interne sur les modalités d’isolement des patients chez qui une tuberculose est recherchée, ainsi que de tester des scores décisionnels afin d’optimiser la mise en place des mesures d’isolement. Patients et méthodes Il s’agit d’une étude observationnelle rétrospective réalisée dans un service de médecine interne. Les patients ayant bénéficié d’une recherche de tuberculose du 1e avril 2010 au 31 mars 2015 ont été recensés grâce au service de bactériologie et seuls les patients ayant au moins 1 prélèvement positif ont été inclus. Après analyse de la cohorte et des modalités d’isolement à partir des dossiers médicaux, 2 scores décisionnels d’isolement ont été testés sur la population : (i) le score de Tattevin et al. obtenu en pondérant les facteurs prédictifs de tuberculose identifiés en analyse multivariée ; (ii) le score de Wisnievki et al. établi à partir d’une population à faible prévalence de tuberculose. Résultats Vingt-quatre patients ont été inclus soit une incidence de 2 %. Les deux tiers des patients étaient atteints d’une tuberculose pulmonaire et un quart avait une forme extrapulmonaire associée. Les principaux facteurs de risque retrouvés étaient l’antécédent de tuberculose et un contage. La majorité des patients était symptomatique au moment du diagnostic (87,5 %, n = 21), avec prédominance d’altération de l’état général, de fièvre et de signes respiratoires dans 74 % des cas (n = 18). La totalité des patients a bénéficié d’une imagerie thoracique, retrouvant des signes de tuberculose dans plus de 70 % des cas. Tous les patients ont eu une recherche bactériologique de tuberculose pulmonaire. Le délai moyen de réalisation des prélèvements par rapport à l’entrée est de 5 jours. Seuls 70 % ont bénéficié d’au moins 3 prélèvements conformément aux recommandations. Plus de la moitié des prélèvements (58,3 %, n = 14) étaient négatifs à l’examen direct. Seuls 15 patients ont été isolés et parmi les 6 patients non isolés (3 données manquantes), tous ont eu un résultat d’examen direct négatif. Parmi les patients bacillifères, 30 % (n = 3) ont été isolés dès l’entrée. Le délai moyen d’isolement était de 1,8 jours Le taux d’isolement chez les patients ayant un résultat d’examen direct positif était de 100 %. Il n’a été diagnostiqué aucun cas de tuberculose secondaire parmi le personnel soignant. Le score de Tattevin et al. a une sensibilité de 54 % sur cette population alors que l’application du score de Wisnieski et al. permettrait l’isolement de 92 % des patients. Conclusion Cette étude met donc en évidence (i) la faible incidence de la tuberculose dans les services de médecine interne ; (ii) les difficultés de mise en œuvre des mesures d’isolement respiratoire recommandées ; (iii) la fréquence des résultats d’examen direct négatifs, confirmant donc la faible sensibilité de cet examen ; (iv) l’absence de transmission nosocomiale malgré les défauts d’isolement. La validation de scores décisionnels adaptés aux populations à faible prévalence est donc nécessaire pour identifier rapidement les patients nécessitant un isolement et la généralisation de méthodes diagnostiques rapides pourrait être utile pour lever au plus vite les isolements par excès et donc minimiser leur impact et leurs contraintes logistique

Végétation tricuspidienne au cours d’une maladie de Still, une manifestation non infectieuse rare de lésion intracardiaque [Intra-cardiac manifestation during adult-onset Still's disease's, a tricuspid vegetation as a rare expression of systemic disease]

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Spectral characteristics of soil dissolved organic matter: Long-term effects of exogenous organic matter on soil organic matter and spatial-temporal changes

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Gas chromatography coupled-to Fourier transform orbitrap mass spectrometer for enantioselective amino acid analyses: Application to pre-cometary organic analog

International audienceGas chromatography (GC) is a separation technique commonly developed for targeted in situ analyses in planetary space missions. It is coupled with low-resolution mass spectrometry to obtain additional structural information and allow compound identification. However, ground-based analyses of extraterrestrial samples have shown the presence of large molecular diversities. For future targeted in situ analyses, it is therefore essential to develop new technologies. High resolution mass spectrometry (HRMS) is currently being spatialized using FT-orbitrap-MS technology. In this contribution, the coupling of gas chromatography with FT-orbitrap-MS is studied for targeted amino acid analyses. The method for enantioselective separation of amino acids was optimized on a standard mixture comprising 47 amino acid enantiomers. Different ionization modes were optimized, chemical ionization with three different reactive gases (NH 3 , CH 4 and NH 3 /CH 4) and electron impact ionization at different electron energies. Single ion and full scan monitoring modes were compared, and detection and quantification limits were estimated by internal calibration under the optimized conditions. The GC-FT-orbitrap-MS demonstrated its ability to separate 47 amino acid enantiomers with minimal co-elution. Furthermore, due to the high mass resolution and accuracy of FT-orbitrap-MS, with mass extraction, the S/N is close to zero, allowing average LOD values of 10⁻ 7 M, orders of magnitude lower than conventional GC-MS techniques. Finally, these conditions were tested for enantioselective analysis of amino acids on an analog of a pre-cometary organic material showing similarities to that of extraterrestrial materials

Innovative methods measuring sensory interactions

In-mouth perception of food is complex and due to a tricky combination of aroma, taste and texture perceptions. Together, these three modalities are key factors that determine consumer’s food acceptance. Whereas lots of studies had been done to study cross-modal interactions between aroma, taste and texture perception in food, few of them had been able to determine the relative contribution of each modality to the global perception of complex food products without using model food matrices [1]. Our study deals with the development of two original concepts. The former aims to decrypt aroma, taste and texture interactions and the latter to understand their relationships with the physicochemical properties of food product. Therefore, the relative contributions of aroma, taste and texture modalities to overall perception, as well as the interactions which can occur between them, were studied during the consumption of real foods as apples. We developed an innovative sensory approach [2] where aroma, taste and texture perceptions were masked by using different masking agents, allowing then to omit one or several of these sensory modalities during various matching tasks. A multiblock data treatment methodology called Common Components and Specific Weights Analysis (CCSWA) [3] was used to analyse data set issued from rating and matching sensory experiments. Taste was the modality which contributed the most to the discrimination between apples. It was followed respectively by texture and aroma modalities. While taste and texture did not seem to show cross-modal interactions, a binary taste-taste interaction was shown between sweetness and acid taste. In a similar way, cross-modal interactions between olfactory and gustative perceptions were demonstrated. To go further, the Food Aroma Research Group of ONIRIS (UMR GEPEA 6144 GEPEA) has developed an original system, named the MMS “Mouth to Nose Merging System” dedicated to establish the relationship between cognitive perception and the physicochemical properties of a food product [4]. This innovative device combines artificial mastication, aroma release with human sensory evaluation. Judges were asked to eat an apple piece, inducing texture and taste perception, while another odorant extract obtained by artificial mastication was sent to the nose of judges. This method allowed us to understand how orthonasal aroma influenced aroma, taste and texture perception. An integrative device of “in mouth simulator” named AMADEUS is also now available to analyse aroma and taste components during mastication [5]. To conclude, these whole strategies applied on apples have permitted to describe cross-modal interactions and posed hypothesis concerning their physico-chemical, physiological or cognitive origin

Enhancing tumor response to targeted chemotherapy through up-regulation of folate receptor α expression induced by dexamethasone and valproic acid

International audienceSeveral folate-drug conjugates are currently undergoing clinical trials for application in oncology. However, the efficacy of folate-targeted therapy strongly depends on the folate receptor (FR) abundance at the surface of cancer cells. Recently, it has been postulated that up-regulation of FRα by means of chemo-sensitizing agents could enhance the anticancer activity of FR-drug conjugates. In this study, we demonstrate in vitro that a combination of dexamethasone (Dexa) and valproic acid (VPA) increases FRα expression selectively at the surface of FR-overexpressing cancer cells. The same stimulation was observed in vivo in KB-tumor xenografts when mice are treated with this combined treatment. This effect is reversible since treatment interruption induces the return of FR expression at basal level. When incubated with Dexa and VPA, the β-galactosidaseresponsive folate-monomethyl auristatin E (MMAE) conjugate, called MGAF, exhibits higher cytotoxic activity on several FR-positive human cancer cell lines, compared to its administration as a single agent. This improved toxicity results from the enhanced concentration of MMAE released within cancer cells after internalization and subsequent enzymatic activation of MGAF. Higher deposition of MMAE is also observed in vivo after up-regulation of FR expression level in tumor xenografts, induced by the prior administration of the Dexa/VPA combination. In this model, MGAF/Dexa/VPA combined therapy results in an 81% inhibition of tumor growth compared to the control group, while MGAF used in monotherapy is inefficient. Since Dexa and VPA are currently used in humans, this finding could be of great interest for further development of folate-drug conjugates, in particular for those that are presently under clinical investigation