Search results for "Intestin"

Seasonal and ontogenetic shifts in the diet of Arctic charr Salvelinus alpinus in a subarctic lake.

2010

Seasonal and ontogenetic shifts in the diet of Arctic charr Salvelinus alpinus were studied in a deep, ultra-oligotrophic lake in subarctic Finland from both stomach contents and the stable carbon (delta(13)C) and nitrogen (delta(15)N) isotope compositions of muscle and liver tissues. Both diet and isotope results indicated that the S. alpinus population relied mainly on littoral benthic energy sources. The strong littoral reliance appeared largely independent of season or fish size, although the data lacked small (total length, L(T),130 mm) and young (3 years) S. alpinus. Liver isotope values of intermediate-sized S. alpinus (200-350 mm), however, suggested exploitation of the increase in …

Factors influencing infection patterns of trophically transmitted parasites among a fish community: host diet, host-parasite compatibility or both?

2011

20 pages; International audience; Parasite infection patterns were compared with the occurrence of their intermediate hosts in the diet of nine sympatric fish species in a New Zealand lake. Stomach contents and infection levels of three gastrointestinal helminth species were examined from the entire fish community. The results highlighted some links between fish host diet and the flow of trophically transmitted helminths. Stomach contents indicated that all but one fish species were exposed to these helminths through their diet. Host feeding behaviour best explained infection patterns of the trematode Coitocaecum parvum among the fish community. Infection levels of the nematode Hedruris spi…

Interpreting immunological indices: the importance of taking parasite community into account. An example in blackbirds Turdus merula.

2015

13 pages; International audience; Despite the intensive use of immune indices in immunoecology, whether to interpret the results of immune indices in terms of actual immune competence (i.e. ability to control and clear parasite infections as indicated by high values of immune indices associated with low parasite loads) or current immune activation (pathogenic infection being associated with high parasite load and high values of immune indices) is still an open question. Most studies to date have produced contrasting results focused on the effect of a single parasite species despite the fact that hosts usually harbour a community of parasites that influences one another's impact on host immu…

Applying the Anna Karenina principle for wild animal gut microbiota: Temporal stability of the bank vole gut microbiota in a disturbed environment.

2020

Gut microbiota play an important role in host health. Yet, the drivers and patterns of microbiota imbalance (dysbiosis) in wild animals remain largely unexplored. One hypothesised outcome of stress on animal microbiomes is a destabilised microbial community that is characterised by an increase in inter-individual differences compared with microbiomes of healthy animals, which are expected to be (a) temporally stable and (b) relatively similar among individuals. This set of predictions for response of microbiomes to stressors is known as the Anna Karenina principle (AKP) for animal microbiomes. We examine the AKP in a wild mammal inhabiting disturbed environments by conducting a capture-mark…

2020

α-Linolenic acid (ALA) is well-known for its anti-inflammatory activity. In contrast, the influence of an ALA-rich diet on intestinal microbiota composition and its impact on small intestine morphology are not fully understood. In the current study, we kept adult C57BL/6J mice for 4 weeks on an ALA-rich or control diet. Characterization of the microbial composition of the small intestine revealed that the ALA diet was associated with an enrichment in Prevotella and Parabacteroides. In contrast, taxa belonging to the Firmicutes phylum, including Lactobacillus, Clostridium cluster XIVa, Lachnospiraceae and Streptococcus, had significantly lower abundance compared to control diet. Metagenome p…

Environmental radiation alters the gut microbiome of the bank vole Myodes glareolus.

2018

International audience; Gut microbiota composition depends on many factors, although the impact of environmental pollution is largely unknown. We used amplicon sequencing of bacterial 16S rRNA genes to quantify whether anthropogenic radionuclides at Chernobyl (Ukraine) impact the gut microbiome of the bank vole Myodes glareolus. Exposure to elevated levels of environmental radionuclides had no detectable effect on the gut community richness but was associated with an almost twofold increase in the Firmicutes:Bacteroidetes ratio. Animals inhabiting uncontaminated areas had remarkably similar gut communities irrespective of their proximity to the nuclear power plant. Hence, samples could be c…

Quantitative patterns of Hsps in tubular adenoma compared with normal and tumor tissues reveal the value of Hsp10 and Hsp60 in early diagnosis of lar…

2016

Large bowel carcinogenesis involves accumulation of genetic alterations leading to transformation of normal mucosa into dysplasia and, lastly, adenocarcinoma. It is pertinent to elucidate the molecular changes occurring in the pre-neoplastic lesions to facilitate early diagnosis and treatment. Heat shock proteins (Hsps), many of which are molecular chaperones, are implicated in carcinogenesis, and their variations with tumor progression encourage their study as biomarkers. There are many reports on Hsps and cancer but none to our knowledge on their systematic quantification in pre-neoplastic lesions of the large bowel. We performed immunohistochemical determinations of Hsp10, Hsp60, Hsp70, …

Succinate receptor mediates intestinal inflammation and fibrosis.

2018

Succinate, an intermediate of the tricarboxylic acid cycle, is accumulated in inflamed areas and its signaling through succinate receptor (SUCNR1) regulates immune function. We analyze SUCNR1 expression in the intestine of Crohn's disease patients and its role in murine intestinal inflammation and fibrosis. We show that both serum and intestinal succinate levels and SUCNR1 expression in intestinal surgical resections were higher in CD patients than in controls. SUCNR1 co-localized with CD86, CD206, and alpha-SMA(+) cells in human intestine and we found a positive and significant correlation between SUCNR1 and alpha-SMA expression. In human isolated fibroblasts from CD patients SUCNR1 expres…

Therapeutic drug monitoring as a tool to optimize 5-FU-based chemotherapy in gastrointestinal cancer patients older than 75 years.

2019

Abstract Aims Most clinical trials exclude elderly people, leading to a limited understanding of the benefit-to-risk ratio in this population. Despite existing data regarding the oncological management of elderly receiving fluorouracil (5-FU)-based regimen, our objective was to investigate 5-FU exposure/toxicity relationship in patients ≥75 years and compare the effectiveness of 5-FU therapeutic drug monitoring between elderly and younger patients. Methods Hundred fifty-four patients (31 of whom are older than 75 years) with gastrointestinal cancers, who were to receive 5-FU–based regimens, were included in our study. At cycle 1 (C1), the 5-FU dose was calculated using patient's body surfac…

M1 Macrophages Activate Notch Signalling in Epithelial Cells: Relevance in Crohn's Disease

2016

Background: The Notch signalling pathway plays an essential role in mucosal regeneration, which constitutes a key goal of Crohn's disease (CD) treatment. Macrophages coordinate tissue repair and several phenotypes have been reported which differ in the expression of surface proteins, cytokines and hypoxia-inducible factors (HIFs). We analysed the role of HIFs in the expression of Notch ligands in macrophages and the relevance of this pathway in mucosal regeneration. Methods: Human monocytes and U937-derived macrophages were polarized towards the M1 and M2 phenotypes and the expression levels of HIF-1α, HIF-2α, Jagged 1 (Jag1) and delta-like 4 (Dll4) were evaluated. The effects of macrophage…