Granulomatous enteritis in rainbow trout (Oncorhynchus mykiss) associated with soya bean meal regardless of water dissolved oxygen level.

This study investigated morphological changes associated with soya bean meal-induced enteritis (SBMIE) in distal intestine (DI) of rainbow trout (Oncorhynchus mykiss) fed a soya bean meal (SBM)-based diet and exposed to normoxia or hypoxia created by optimal and low water flow rates, respectively. A 28-day adaption period was followed by a 42-day challenge period where 600 fish were subjected to dietary challenge and/or hypoxia. Twelve tanks each containing 50 juvenile trout were assigned randomly in triplicate to each treatment.

Bacterial translocation and in vivo assessment of intestinal barrier permeability in rainbow trout (Oncorhynchus mykiss) with and without soyabean meal-induced inflammation.

The primary aim of this experiment was to evaluate the intestinal barrier permeability in vivo in rainbow trout (Oncorhynchus mykiss) fed increasing levels of soyabean meal (SBM). The relationship between SBM-induced enteritis (SBMIE) and the permeability markers was also investigated. Our results showed that the mean score of morphological parameters was significantly higher as a result of 37·5 % SBM inclusion in the diet, while the scores of fish fed 25 % SBM or lower were not different from those of the fish meal-fed controls (P < 0·05).

Candida utilis and Chlorella vulgaris counteract intestinal inflammation in Atlantic salmon (Salmo salar L.).

Intestinal inflammation, caused by impaired intestinal homeostasis, is a serious condition in both animals and humans. The use of conventional extracted soybean meal (SBM) in diets for Atlantic salmon and several other fish species is known to induce enteropathy in the distal intestine, a condition often referred to as SBM induced enteropathy (SBMIE). In the present study, we investigated the potential of different microbial ingredients to alleviate SBMIE in Atlantic salmon, as a model of feed-induced inflammation.

Prevention of soya-induced enteritis in Atlantic salmon (Salmo salar) by bacteria grown on natural gas is dose dependent and related to epithelial MHC II reactivity and CD8α+ intraepithelial lymphocytes.

An experiment was carried out to study the preventive effect of bacterial meal (BM) produced from natural gas against plant-induced enteropathy in Atlantic salmon (Salmo salar). Salmon were fed a diet based on fish meal (FM) or seven diets with 200 g/kg solvent-extracted soyabean meal (SBM) to induce enteritis in combination with increasing levels of BM from 0 to 300 g/kg. Salmon fed a SBM-containing diet without BM developed typical SBM-induced enteritis.

Phenotypic characterization of cells participating in transport of prion protein aggregates across the intestinal mucosa of sheep.

The oral route is considered to be the main entry site of several transmissible spongiform encephalopathies or prion diseases of animals and man. Following natural and experimental oral exposure to scrapie, sheep first accumulate disease associated prion protein (PrP (d) ) in Peyer's patch (PP) lymphoid follicles. In this study, recombinant ovine prion protein (rPrP) was inoculated into gut loops of young lambs and the transportation across the intestinal wall studied.

Exosome-producing follicle associated epithelium is not involved in uptake of PrPd from the gut of sheep (Ovis aries): an ultrastructural study.

In natural or experimental oral scrapie infection of sheep, disease associated prion protein (PrP(d)) often first accumulates in Peyer's patch (PP) follicles. The route by which infectivity reaches the follicles is unknown, however, intestinal epithelial cells may participate in intestinal antigenic presentation by delivering exosomes as vehicles of luminal antigens. In a previous study using an intestinal loop model, following inoculation of scrapie brain homogenate, inoculum associated PrP(d) was detected by light microscopy shortly (15 minutes to 3.

Bacteria grown on natural gas prevent soybean meal-induced enteritis in Atlantic salmon.

Dietary inclusion of solvent extracted soybean meal (SBM) is associated with inflammation in the distal intestine of salmonid fish, commonly referred to as SBM-induced enteritis. The enteritis is linked to alcohol soluble components in SBM, but the mechanisms have not been established. Previous studies show that bacterial meal (BM) containing mainly Methylococcus capsulatus grown on natural gas is a suitable protein source for salmonids.

PrP expression, PrPSc accumulation and innervation of splenic compartments in sheep experimentally infected with scrapie.

Background: In prion disease, the peripheral expression of PrP(C) is necessary for the transfer of infectivity to the central nervous system. The spleen is involved in neuroinvasion and neural dissemination in prion diseases but the nature of this involvement is not known. The present study undertook the investigation of the spatial relationship between sites of PrP(Sc) accumulation, localisation of nerve fibres and PrP(C) expression in the tissue compartments of the spleen of scrapie-inoculated and control sheep.

Decreased expression of TGF-beta, GILT and T-cell markers in the early stages of soybean enteropathy in Atlantic salmon (Salmo salar L.).

This study investigated the early expression of T-cell markers and genes potentially involved in the induction of soybean meal (SBM) enteropathy in the distal intestine (DI) of Atlantic salmon (Salmo salar L.). Quantitative PCR was used to study the expression of CD3, CD8beta, transforming growth factor beta (TGF-beta), interferon-gamma-inducible lysosomal thiol reductase (GILT) and interleukin-1beta (IL-1beta) in salmon fed SBM for 1, 3 and 7 days using fish fed fishmeal as controls.

Rapid induction of experimental AA amyloidosis in mink by intravenous injection of amyloid enhancing factor.

Studies of amyloid enhancing factor (AEF)-induced amyloidosis are commonly performed in mice. In mink, earlier studies of amyloid A (AA) amyloidosis showed that the predeposition phase was highly variable. Thus, the aim of the study was to establish an AEF-induced AA amyloidosis model in mink to facilitate studies of early amyloid deposition in a species with prominent ellipsoids, anatomical structures lacking in mice but present in most other mammals.

Effects of dietary soyabean meal, inulin and oxytetracycline on intestinal microbiota and epithelial cell stress, apoptosis and proliferation in the teleost Atlantic salmon (Salmo salar L.).

Soyabean meal (SBM)-induced enteritis in the distal intestine of the teleost Atlantic salmon (Salmo salar L.) and other salmonids may be considered a model for diet-related mucosal disorders in other animals and man. The role of the intestinal microbiota in its pathogenesis was explored.

Histological, digestive, metabolic, hormonal and some immune factor responses in Atlantic salmon, Salmo salar L., fed genetically modified soybeans.

The paper reports the second and final part of an experiment aiming to study physiological and health-related effects of genetically modified (GM) soybean meal (SBM) type Roundup Ready soybean (RRS) in diets for post-smolt Atlantic salmon. For 3 months salmon were fed diets containing 172 g kg(-1) full-fat SBM from RRS (GM-soy) or an unmodified, non-isogenic line (nGM-soy), or a reference diet with fishmeal as the sole protein source (FM). Slight differences in anti-nutrient levels were observed between the GM and nGM-soy.

Response to soy: T-cell-like reactivity in the intestine of Atlantic salmon, Salmo salar L.

T-cell-mediated hypersensitivity could be central in soybean meal (SBM)-induced intestinal changes in salmon. However, tools for immunohistochemical detection of T cells have been lacking in teleosts, including Atlantic salmon. Application of a specific histochemical protocol allowed demonstration of T-cell-like reactivities in formalin-fixed, paraffin-embedded tissues using an antibody reacting to a conserved region of human CD3epsilon (Dako A0452).

Pancreatitis associated with hyperlipoproteinaemia type I in mink (Mustela vison): earliest detectable changes occur in mitochondria of exocrine cells.

Pancreatic tissue from young mink homozygous for a mutation in the lipoprotein lipase gene was studied by light and electron microscopy, with the aim of describing the earliest detectable changes in a process which rapidly progresses into overt pancreatitis. The mutation leads to hyperlipoproteinaemia, corresponding to hyperlipoproteinaemia type I in man. Assessment of relevant hepatic and pancreatic enzymes were included in the investigation.

Transportation of prion protein across the intestinal mucosa of scrapie-susceptible and scrapie-resistant sheep.

To determine the mechanisms of intestinal transport of infection, and early pathogenesis, of sheep scrapie, isolated gut-loops were inoculated to ensure that significant concentrations of scrapie agent would come into direct contact with the relevant ileal structures (epithelial, lymphoreticular, and nervous). Gut loops were inoculated with a scrapie brain pool homogenate or normal brain or sucrose solution. After surgery, animals were necropsied at time points ranging from 15 min to 1 month and at clinical end point.

Detection of PrP(Sc) in rectal biopsy and necropsy samples from sheep with experimental scrapie.

Scrapie diagnosis is based on the demonstration of disease-associated prion protein (PrP(Sc)) in brain or, in the live animal, in readily accessible peripheral lymphoid tissue. Lymphatic tissues present at the rectoanal line were readily obtained from sheep without the need for anaesthesia. The presence of PrP(Sc) in such tissue was investigated in sheep infected orally with scrapie-infected brain material.

Reduced apoptosis in sheep ileal Peyer's patch is associated with low levels of follicle centre carbonic anhydrase reactivity.

Apoptosis in lymphoid follicles of the ileal Peyer's patch (IPP) in 21 sheep of two different age groups was visualized by the TdT-mediated dUTP nick end-labelling (TUNEL) method, and quantified using computer-assisted image analysis. The IPP follicle carbonic anhydrase (CA) reactivity was evaluated in the same samples. No significant differences with respect to apoptosis and CA reactivity were found between sheep aged 5 and 11 months.

Filter function and immune complex trapping in splenic ellipsoids.

The role of splenic ellipsoids in the trapping of particulate material and immune complexes was investigated in mink (Mustela vison). The ellipsoids were prominent, with typical features such as a permeable endothelium and a discontinuous basement membrane surrounded by a sheath of macrophages and reticular cells. Ellipsoidal trapping of circulating particles was demonstrated 10 min after intracardiac injection of colloidal carbon and fluorescent microspheres.

Mapping PrPSc propagation in experimental and natural scrapie in sheep with different PrP genotypes.

Twenty-one orally inoculated and seven naturally infected sheep with scrapie were examined for PrP(Sc) in peripheral tissues and in the central nervous system (CNS), using immunohistochemistry. In the inoculated group, VRQ (valine at codon 136, arginine at codon 154 and glutamine at codon 171)/VRQ sheep generally had a greater accumulation of the pathologic form of prion protein (PrP(Sc)) in peripheral tissues, as compared with VRQ/ARQ (alanine at codon 136, arginine at codon 154, and glutamine at codon 171) animals at corresponding time points after inoculation. PrP(Sc) was not detected in the ileal Peyer's patch, the spleen, the superficial cervical lymph node, and peripheral nervous tissues of several inoculated VRQ/ARQ animals.

Lymphoid follicles of different phenotype appear in ileum during involution of the sheep ileal Peyer's patch.

The ileal Peyer's patch (IPP) of young sheep is a site of diversification of the primary antibody repertoire and where involution takes place at young age. Tissue samples from the ileum were collected in 134 animals aged from 1 month to 6 years, and IPP follicle phenotypes were characterised. We describe a new type of ileal lymphoid follicles that became relatively more frequent during involution, and had numerous intrafollicular T-cells and BAQ44A+ B-cells and large interfollicular T-cell areas.

Differentiation of the follicle-associated epithelium in ileal Peyer's patch and production of 50-nm particles are maintained in B-cell-depleted fetal sheep.

To evaluate the dependence of the differentiation of the follicle-associated epithelium (FAE) on the presence of follicular B-cells, the FAE of ileal Peyer's patch follicles was examined in B-cell-depleted fetal lambs. The FAE of these rudimentary follicles, which are devoid of lymphocytes, showed normal differentiation, including carbonic anhydrase reactivity and ultrastructural characteristics of transcytosis, extensive interdigitation of the lateral plasma membrane and the shedding of membrane-bounded particles, approximately 50 nm in size, resembling exosomes. These 50-nm membrane-bounded particles were abundant in the extracellular space of the epithelium and the dome but no particles were found in the rudimentary follicles.

Kinetics of glycosaminoglycan deposition in splenic AA amyloidosis induced in mink.

The kinetics of splenic glycosaminoglycan (GAG) expression in mink has been investigated during the course of AA amyloid induction, i.e. at 3 to 6 weeks of lipopolysaccharide (LPS) treatment.

Accumulation of CD25+ CD4+ T-cells in the draining lymph node during the elicitation phase of DNCB-induced contact hypersensitivity in lambs.

The elicitation phase of DNCB induced contact hypersensitivity in lambs was studied, and the presence of CD25+ cells in the lymph nodes draining the contact site was measured. Confocal laser scanning microscopy was used to capture images of two sets of triple immunofluorescence labellings. One set labelled CD25+, CD4+ and CD3+ cells, while the other labelled CD25+, VPM30+ and CD4+ cells.

Splenic ellipsoids: an early target for deposition of AA amyloid induced in mink.

The spleen is the primary target for spontaneous as well as experimental AA amyloidosis in animals such as mice and mink, and is therefore a valuable organ for study of the initial phases of amyloid fibrillogenesis and deposition. We have investigated splenic amyloid AA deposits induced in the mink, and we demonstrate a novel target for AA, namely the splenic ellipsoids. We show presence of amyloid P component (AP), glycosaminoglycans (GAGs) and apolipoprotein E (apoE), all well-known common elements of amyloid, co-localizing with AA.

The effect of dosage, gestational age and splenectomy on anti-IgM interception of prenatal B-cell development in sheep.

The administration of a single bolus of anti-IgM antibody to foetal lambs early in pregnancy produces prolonged B-cell depletion. The present study investigated this depletion by examining the effect, on B-cell development in the ileal Peyer's patches, of varying the timing and dosage of antibody administration and by supplementing anti-IgM with surgical splenectomy. The capacity of a 1 mg bolus of anti-IgM to deplete Peyer's patches of B cells was lost if its administration was deferred until two thirds of the way through pregnancy, but persisted beyond this time if weight-adjusted doses were used.