Synthesis of prebiotic galactooligosaccharides from lactose using bifidobacterial β-galactosidase (BbgIV) immobilised on DEAE-Cellulose, Q-Sepharose and amino-ethyl agarose

The bifidobacterial β-galactosidase BbgIV was immobilised on DEAE-Cellulose and Q-Sepharose via ionic binding and on amino-ethyl- and glyoxal-agarose via covalent attachment, and was then used to catalyse the synthesis of galactooligosaccharides (GOS). The immobilisation yield exceeded 90 % using ionic binding, while it was low using aminoethyl agarose (25 – 28 %) and very low using glyoxal agarose (< 3 %). This was due to the mild conditions and absence of chemical reagents in ionic binding, compared to covalent attachment. The maximum GOS yield obtained using DEAE-Cellulose and Q-Sepharose was similar to that obtained using free BbgIV (49 – 53 %), indicating the absence of diffusion limitation and mass transfer issues. For amino-ethyl agarose, however, the GOS yield obtained was lower (42 – 44 %) compared to that obtained using free BbgIV. All the supports tried significantly (P < 0.05) increased the BbgIV operational stability and the GOS synthesis productivity up to 55 °C. Besides, six successive GOS synthesis batches were performed using BbgIV immobilised on Q-Sepharose; all resulted in similar GOS yields, indicating the possibility of developing a robust synthesis process. Overall, the GOS synthesis operation performance using BbgIV was improved by immobilising the enzyme onto solid supports, in particular on Q-Sepharos

Stellar Population Constraints on the Dark Matter Content and Origin of Ultra-Compact Dwarf Galaxies

We analyse intermediate-resolution VLT FLAMES/Giraffe spectra of six ultra-compact dwarf (UCD) galaxies in the Fornax cluster. We obtained velocity dispersions and stellar population properties by full spectral fitting against PEGASE.HR models. Objects span a large range of metallicities (-0.95 to -0.23 dex), 4 of them are older than 8 Gyr. Comparison of the stellar and dynamical masses suggests that UCDs have little dark matter at best. For one object, UCD3, the Salpeter initial mass function (IMF) results in the stellar mass significantly exceeding the dynamical one, whereas for the Kroupa IMF the values coincide. Although, this object may have peculiar dynamics or/and stellar populations, the Kroupa IMF seems more realistic. We find that UCDs lie well above the metallicity-luminosity relation of early-type galaxies. The same behaviour is demonstrated by some of the massive Milky Way globular clusters, known to contain composite stellar populations. Our results support two following UCD formation scenarii: (1) tidal stripping of nucleated dwarf elliptical galaxies; (2) formation of tidal superclusters in galaxy mergers. We also discuss some of the alternative channels of the UCD formation binding them to globular clusters.Comment: accepted to MNRAS, 7 pages, 4 figures, 3 table

Time to Switch to Second-line Antiretroviral Therapy in Children With Human Immunodeficiency Virus in Europe and Thailand.

Background: Data on durability of first-line antiretroviral therapy (ART) in children with human immunodeficiency virus (HIV) are limited. We assessed time to switch to second-line therapy in 16 European countries and Thailand. Methods: Children aged <18 years initiating combination ART (≥2 nucleoside reverse transcriptase inhibitors [NRTIs] plus nonnucleoside reverse transcriptase inhibitor [NNRTI] or boosted protease inhibitor [PI]) were included. Switch to second-line was defined as (i) change across drug class (PI to NNRTI or vice versa) or within PI class plus change of ≥1 NRTI; (ii) change from single to dual PI; or (iii) addition of a new drug class. Cumulative incidence of switch was calculated with death and loss to follow-up as competing risks. Results: Of 3668 children included, median age at ART initiation was 6.1 (interquartile range (IQR), 1.7-10.5) years. Initial regimens were 32% PI based, 34% nevirapine (NVP) based, and 33% efavirenz based. Median duration of follow-up was 5.4 (IQR, 2.9-8.3) years. Cumulative incidence of switch at 5 years was 21% (95% confidence interval, 20%-23%), with significant regional variations. Median time to switch was 30 (IQR, 16-58) months; two-thirds of switches were related to treatment failure. In multivariable analysis, older age, severe immunosuppression and higher viral load (VL) at ART start, and NVP-based initial regimens were associated with increased risk of switch. Conclusions: One in 5 children switched to a second-line regimen by 5 years of ART, with two-thirds failure related. Advanced HIV, older age, and NVP-based regimens were associated with increased risk of switch

Thresholds related to the management of the North Sea coastal area :focus on the eutrophied Belgian coastal zone (BCZ)

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A thioredoxin-mimetic peptide exerts potent anti-inflammatory, antioxidant, and atheroprotective effects in ApoE2.Ki mice fed high fat diet

International audienceTime for primary review: 40 days Aims Oxidative stress and inflammation play a pathogenic role in atherosclerosis. Thioredoxin-1 (Trx-1) is an antioxidative, anti-inflammatory protein with atheroprotective effects. However, in vivo cleavage of Trx-1 generates a truncated pro-inflammatory protein, Trx-80, which compromises the therapeutic use of Trx-1. Here we analysed whether the thioredoxin-mimetic peptide (TxMP), CB3 might exert anti-oxidative, anti-inflammatory, and atheroprotective effects in ApoE2.Ki mice

A thioredoxin-mimetic peptide exerts potent anti-inflammatory, antioxidant, and atheroprotective effects in ApoE2.Ki mice fed high fat diet

International audienc

Bovine leukaemia virus-induced lymphocytosis in sheep is associated with reduction of spontaneous B cell apoptosis

International audienc

Immunité et cancers des voies aéro-digestives supérieures 1

Les cancers des voies aéro-digestives supérieures (VADS) sont un problème de santé publique majeur. Chez l’homme, ces cancers arrivent en troisième place en termes de fréquence en France. Le pronostic est sombre, la survie des patients ne dépasse pas 20 % à 10 ans. Il est nécessaire de s’intéresser à l’environnement tumoral, afin de mieux comprendre les étapes de formation et d’extension, ainsi que les interactions avec le système immunitaire de l’hôte. L’identification de nouveaux biomarqueurs, témoins du processus cancéreux mais aussi d’une éventuelle réponse immunitaire anti-tumorale pourraient constituer des éléments du diagnostic et du pronostic, mais aussi des cibles thérapeutiques. Cette revue de la littérature a pour but de faire le point sur la réponse immunitaire et l’échappement tumoral des cancers des VADS