Human milk fat globules: Polar lipid composition and in situ structural investigations revealing the heterogeneous distribution of proteins and the lateral segregation of sphingomyelin in the biological membrane

 Human milk fat globules: Polar lipid composition and in situ structural investigations revealing the heterogeneous distribution of proteins and the lateral segregation of sphingomyelin in the biological membran

Gastric and enterohepatic helicobacters other than Helicobacter pylori

During the past year, research on non-Helicobacter pylori species has intensified. H. valdiviensis was isolated from wild birds, and putative novel species have been isolated from Bengal tigers and Australian marsupials. Various genomes have been sequenced: H. bilis, H. can is, H. macacae, H. fennelliae, H. cetorum, and H. sun. Several studies highlighted the virulence of non-H. pylori species including H. cinaedi in humans and hyperlipidemic mice or macacae in geriatric rhesus monkeys with intestinal adenocarcinoma. Not surprisingly, increased attention has been paid to the position of Helicobacter species in the microbiota of children and animal species (mice, chickens, penguins, and migrating birds). A large number of experimental studies have been performed in animal models of Helicobacter induced typhlocolitis, showing that the gastrointestinal microbial community is involved in modulation of host pathways leading to chronic inflammation. Animal models of H. sun, H. heilmannii, and H. felis infection have been used to study the development of severe inflammation-related pathologies, including gastric MALT lymphoma and adenocarcinoma

Investigation of an unusual increase in human yersinioses in Creuse, France

Objectives: To investigate an unusual cluster of Y. enterocolitica 4/O:3/VIII human infections that occurred in Creuse (France) during the summer 2008, and to perform retrospective and prospective analyses of yersiniosis cases to get a better view of the general trend. Methods: 33 pathogenic Y. enterocolitica strains isolated between 2008 and 2010 in Creuse were subjected to phenotypic and molecular typing. The database of the Yersinia National Reference Laboratory was used to compare the number of human cases over 23 years in Creuse and at the national level. Results: The 33 isolates had three distinct phenotypes and a high genetic diversity, ruling out a unique source of contamination. A long-term analysis of yersiniosis cases in Creuse showed a progressive increase over years, with a peak in 2008 and a subsequent decrease. This trend contrasted with the national cases that showed an opposite pattern. Conclusions: Local environmental conditions were most likely responsible for a transient expansion of pathogenic Y. enterocolitica strains in Creuse

A climatological database of the Linke turbidity factor

Abstract – The Linke turbidity factor is an important parameter in solar radiation studies. Longterm monthly average values, TLm, are sufficient for most applications. Estimates of TLm may be obtained by way of a linear regression established for several European sites between the sum of the Angström regression coefficients on a monthly basis (am + bm) and the measured TLm. During the European Solar Radiation Atlas (ESRA) project, values of am and bm have been obtained for 710 sites in Europe and countries surrounding the Mediterranean sea, from the analysis of measurements made during the period 19811990. Using the abovementioned formula, these values are turned into climatological values of TL for each month of the year. This data set of TL is unique in the world and attention has been paid to the means of disseminating the resulting information. A World Wide Web site "Helioserve " has been established, which offers an access to the database through a standard HTML interface. The customers of the Helioserve site are professionals, in research or industry. The database outputs are used as inputs into their own models for atmospheric optics. The site Helioserve comprises also a numerical simulation aspect, which provides to the customer, estimates of the clear sky radiation by running the clearsky model of the ESRA. The TL values requested by the model can be supplied by either the database using an internal query, or the customer himself, or can be set to default values. 1

The Cytolethal Distending Toxin Subunit CdtB of Helicobacter Induces a Th17-related and Antimicrobial Signature in Intestinal and Hepatic Cells In Vitro

International audienceEnterohepatic Helicobacter species are associated with several digestive diseases. Helicobacter pullorum is an emerging human foodborne pathogen, and Helicobacter hepaticus is a mouse pathogen; both species are associated with intestinal and/or hepatic diseases. They possess virulence factors, such as cytolethal distending toxin (CDT). Data indicate that CDT may be involved in chronic inflammatory responses, via its active subunit, CdtB. The proinflammatory properties of the CdtB of H. pullorum and H. hepaticus were assessed on human intestinal and hepatic epithelial cells in vitro. Interleukin 8 expression was evaluated by using wild-type strains and their corresponding CdtB isogenic mutants and by delivering CdtB directly into the cells. Nuclear factor κB nuclear translocation and transcriptomic characteristics in response to CdtB were also evaluated. The CdtB of these Helicobacter species induced nuclear factor κB nuclear translocation and exhibited proinflammatory properties, mainly the expression of T-helper type 17-related genes and genes encoding antimicrobial products also involved in cancer. The Histidine residue in position 265 of the CdtB catalytic site appeared to play a role in the regulation of most of these genes. As for flagellin or lipopolysaccharides, CdtB also induced expression of inflammation-associated genes related to antimicrobial activity

Fat globules selected from whole milk according to their size: Different compositions and structure of the biomembrane, revealing sphingomyelin-rich domains

 Milk fat globules are unique delivery systems for biologically active molecules in the gastrointestinal tract. However, their properties have not yet been fully investigated. In this study, we performed a comparative analysis of the polar lipid and fatty acid compositions of milk fat globules as a function of their size and investigated the structure of the milk fat globule membrane (MFGM). An optimised process of microfiltration was used to select the small milk fat globule (SMFG; 1.6 lm) fractions and the large milk fat globule (LMFG; 6.6 lm) fractions from the same initial whole milks (4.2 lm). The SMFG-fractions contained significantly (i) higher amounts of polar lipids, 8.9 ± 0.9 vs 2.7 ± 0.3 mg/g fat for LMFG-fractions and 6.3 ± 0.5 mg/g fat for whole milks, (ii) lower relative proportions of phosphatidylcholine and sphingomyelin in the MFGM, (iii) higher amounts of C12:0, C14:0, C16:0, C18:1 trans, C18:2 c9 tr11, and lower amounts of C18:0 and C18:1 c9 than did LMFG-fractions and whole milks. Whatever the size of native milk fat globules, the biophysical characterisation performed in-situ, using confocal laser scanning microscopy, showed heterogeneities in the MFGM. The lateral segregation of sphingomyelin in rigid liquid-ordered domains, surrounded by the fluid matrix of glycerophospholipids in the liquid-disordered phase, was revealed. The heterogeneous distribution of glycolipids and glycoproteins was also observed in the MFGM. A new model for the structure of the MFGM is proposed and discussed. The physical, chemical and biological consequences, (i) of the differences in milk fat globule compositions according to their size and (ii) of the specific structure of the MFGM due to sphingomyelin remain to be elucidated

Specific IgG Response against <em>Mycobacterium avium paratuberculosis</em> in children and adults with Crohn's disease

International audienceBackground and Aims: Presence of serum antibodies against Mycobacterium avium paratuberculosis (MAP) in Crohn's Disease (CD) as a disease characteristic remains controversial. In the present work, we assessed antibody reactivity of serum and intestinal fluid against four distinct MAP-antigens, including the recently identified MAP-specific lipopentapeptide (L5P). Methods: Immunoglobulin concentrations and specificity against 3 non MAP-specific antigens: glycosyl-transferase-d (GSD), purified protein derivative from MAP (Johnin-PPD), heparin binding haemagglutinin (MAP-HBHA) and one MAP-specific antigen: synthetic L5P were determined by ELISA in gut lavage fluids from adult controls or patients with CD, and in sera of children or adult controls or patients with CD, ulcerative colitis or celiac disease. Results: Total IgA and IgG concentrations were increased in sera of children with CD but were decreased in sera of adults with CD, thereof specificity against MAP antigens was assessed by normalizing immunoglobulin concentrations between samples. In CD patients, IgG reactivity was increased against the four MAP antigens, including L5P in gut lavage fluids but it was only increased against L5P in sera. By contrast, anti-L5P IgG were not increased in patients with ulcerative colitis or celiac disease. Conclusions: A significant increase in anti-L5P IgG is observed in sera of children and adults with CD but not in patients with other intestinal inflammatory diseases. Anti-L5P antibodies may serve as serological marker for CD

Biological effects of the “

A 3-year survey was made of several biological markers in mussels (Mytilus edulis) exposed in situ to the oil that came ashore after the wreck of the “Erika” tanker on the Brittany (France) coast in December 1999. The mussel response was assessed using a set of 7 biomarkers, most of them related to the metabolism of organic contaminants. After a series of validation tests, data was evaluated for only 5 biomarkers: acetylcholinesterase (AChE), glutathione S-transferase (GST), catalase (CAT), malondialdehyde (MDA) and deoxyribonucleic acid (DNA) adducts. No significant reductions in GST or CAT levels were observed, levels of DNA adducts and MDA were high during the 6 months immediately following the accident and levels of AChE were significantly lower during the first year of the survey suggesting a general stress. A simple multivariate graphic method, the integrated biomarker response index, was used to combine 4 of the 5 validated biomarkers and quantify the degree of impact on mussels at different sites. The results show that mussel populations were affected by the oil spill only during the first year after the event