4-Nitro­phenyl α-l-rhamnopyran­oside hemihydrate

In the title compound, C12H15NO7·0.5H2O, there are two independent mol­ecules in the asymmetric unit, together with one water molecule. The pyran­oside rings each have close to a 1 C 4 chair conformation and the nitro groups are almost coplanar with the benzene rings. The water mol­ecule links the two independent mol­ecules through O—H⋯O hydrogen bonds. All the hydroxyl groups are involved in hydrogen-bond inter­actions, giving rise to a three-dimensional network

Characterization of intestinal mononuclear phagocyte subsets in young ruminants at homeostasis and during Cryptosporidium parvum infection

IntroductionCryptosporidiosis is a poorly controlled zoonosis caused by an intestinal parasite, Cryptosporidium parvum, with a high prevalence in livestock (cattle, sheep, and goats). Young animals are particularly susceptible to this infection due to the immaturity of their intestinal immune system. In a neonatal mouse model, we previously demonstrated the importance of the innate immunity and particularly of type 1 conventional dendritic cells (cDC1) among mononuclear phagocytes (MPs) in controlling the acute phase of C. parvum infection. These immune populations are well described in mice and humans, but their fine characterization in the intestine of young ruminants remained to be further explored.MethodsImmune cells of the small intestinal Peyer’s patches and of the distal jejunum were isolated from naive lambs and calves at different ages. This was followed by their fine characterization by flow cytometry and transcriptomic analyses (q-RT-PCR and single cell RNAseq (lamb cells)). Newborn animals were infected with C. parvum, clinical signs and parasite burden were quantified, and isolated MP cells were characterized by flow cytometry in comparison with age matched control animals.ResultsHere, we identified one population of macrophages and three subsets of cDC (cDC1, cDC2, and a minor cDC subset with migratory properties) in the intestine of lamb and calf by phenotypic and targeted gene expression analyses. Unsupervised single-cell transcriptomic analysis confirmed the identification of these four intestinal MP subpopulations in lamb, while highlighting a deeper diversity of cell subsets among monocytic and dendritic cells. We demonstrated a weak proportion of cDC1 in the intestine of highly susceptible newborn lambs together with an increase of these cells within the first days of life and in response to the infection.DiscussionConsidering cDC1 importance for efficient parasite control in the mouse model, one may speculate that the cDC1/cDC2 ratio plays also a key role for the efficient control of C. parvum in young ruminants. In this study, we established the first fine characterization of intestinal MP subsets in young lambs and calves providing new insights for comparative immunology of the intestinal MP system across species and for future investigations on host–Cryptosporidium interactions in target species

Nucléotides-sucrés furaniques (synthèses et activités anti-mycobactériennes)

Les sucres sous forme furanose sont complètement absents chez les mammifères mais présents dans de nombreux micro-organismes souvent pathogènes et responsables de maladies graves telles que la tuberculose, la lèpre, la maladie de Chagas Les enzymes responsables de leur biosynthèse sont peu ou pas connues mais représentent de nouvelles cibles thérapeutiques intéressantes. Au cours de cette thèse, nous avons souhaité développer de nouvelles méthodes de synthèses permettant d obtenir des sucres rares et plus particulièrement des nucléotides-sucres furaniques. Ce mémoire présente dans un premier temps, une approche chimique permettant un accès direct aux cibles visées. Dans un second temps, ce travail met en évidence le potentiel biocatalytique de nucléotidyltransféases pour la préparation de nucléotides-sucres furaniques non naturels. Enfin, les activités biologiques des composés préparés ont été évaluées sur les enzymes intervenants dans la biosynthèse de l arabinogalactane mycobactérien.Furanosides are original glycosides which are presents in several micro-organisms, particulary in pathogenic species, such as those responsible for tuberculosis, leprae, Chagas diseases... The fact that those glycoconjugates are absent in mammal makes those five-membered ring sugars, valuable targets to design new pharmacophores and/or treatments. Therefore, a better understanding of furanoconjugates 's biosynthetic pathways is a crucial step of this new therapeutic strategy. This report presents a straightforward chemical synthesis of nucleotides-sugars from thioimidoyl furanosides. Then, this work underlines also the biocatalytic behavior of nucleotidylyltransferases in order to synthesize non-natural furanosyl nucleotides. At last, activities of those new compounds were evaluated on the enzymes involved in the biosynthesis of the arabinogalactan of Mycobacterium tuberculosis.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

Palmier, efficacité préventive d'une glu

Un des moyens de protéger les palmiers du papillon palmivore est d’opposer une barrière physique à l’infestation de ces végétaux (effet préventif) et à leur ré-infestation (effet préventif au sens strict(1) mais curatif sur le végétal). Quelle barrière ? Une glu tout simplement, plus facile à utiliser qu’à mettre au point…Un des moyens de protéger les palmiers du papillon palmivore est d’opposer une barrière physique à l’infestation de ces végétaux (effet préventif) et à leur ré-infestation (effet préventif au sens strict(1) mais curatif sur le végétal). Quelle barrière ? Une glu tout simplement, plus facile à utiliser qu’à mettre au point ..

Versatile Synthesis of Rare Nucleotide Furanoses

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4-Nitrophenyl -L-rhamnopyranoside hemihydrate

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Recent knowledge and innovations related to hexofuranosides: structure, synthesis and applications

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Insights on the Hydrodynamics of Chiari Malformation.

International audienceBACKGROUND: We propose that the appearance of a ptosis of the cerebellar tonsils and syringomyelia is linked to its own hemohydrodynamic mechanisms. We aimed to quantify cerebrospinal fluid (CSF) and cerebral blood flow to highlight how neurofluid is affected by Chiari malformations type 1(CMI) and its surgery. METHODS: We retrospectively included 21 adult patients with CMI who underwent pre- and postoperative phase contrast MRI (PCMRI) during the period from 2001 to 2017. We analyzed intraventricular CSF, subarachnoid spaces CSF, blood, and tonsils pulsatilities. RESULTS: In preoperative period, jugular venous drainage seems to be less preponderant in patients with syringomyelia than other patients (venous correction factor: 1.49 ± 0.4 vs. 1.19 ± 0.1, p = 0.05). After surgery, tonsils pulsatility decreased significantly (323 ± 175 μL/cardiac cycle (CC) vs. 194 ± 130 μL/CC, p = 0.008) and subarachnoid CSF pulsatility at the foramen magnum increased significantly (201 ± 124 μL/CC vs. 363 ± 231 μL/CC, p = 0.02). After surgery, we found a decrease in venous flow amplitude (5578 ± 2469 mm(3)/s vs. 4576 ± 2084 mm(3)/s, p = 0.008) and venous correction factor (1.98 ± 0.3 vs. 1.20 ± 0.3 mm(3)/s, p = 0.004). CONCLUSIONS: Phase-contrast MRI could be a useful additional tool for postoperative evaluation and follow-up, and is complementary to morphological imaging

Probing UDP-galactopyranose mutase binding pocket: A dramatic effect on substitution of the 6-position of UDP-galactofuranose

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