Transversal gene expression panel to evaluate intestinal health in broiler chickens in different challenging conditions.

There is a high interest on gut health in poultry with special focus on consequences of the intestinal diseases, such as coccidiosis and C. perfringens-induced necrotic enteritis (NE). We developed a custom gene expression panel, which could provide a snapshot of gene expression variation under challenging conditions. Ileum gene expression studies were performed through high throughput reverse transcription quantitative real-time polymerase chain reaction. A deep review on the bibliography was done and genes related to intestinal health were selected for barrier function, immune response, oxidation, digestive hormones, nutrient transport, and metabolism. The panel was firstly tested by using a nutritional/Clostridium perfringens model of intestinal barrier failure (induced using commercial reused litter and wheat-based diets without exogenous supplementation of enzymes) and the consistency of results was evaluated by another experiment under a coccidiosis challenge (orally gavaged with a commercial coccidiosis vaccine, 90× vaccine dose). Growth traits and intestinal morphological analysis were performed to check the gut barrier failure occurrence. Results of ileum gene expression showed a higher expression in genes involved in barrier function and nutrient transport in chickens raised in healthy conditions, while genes involved in immune response presented higher expression in C.perfringens-challenged birds. On the other hand, the Eimeria challenge also altered the expression of genes related to barrier function and metabolism, and increased the expression of genes related to immune response and oxidative stress. The panel developed in the current study gives us an overview of genes and pathways involved in broiler response to pathogen challenge. It also allows us to deep into the study of differences in gene expression pattern and magnitude of responses under either a coccidial vaccine or a NE.

Dietary ß-galactomannans have beneficial effects on the intestinal morphology of chickens challenged with Salmonella enterica serovar Enteritidis.

Salmonella enterica serovar Enteritidis is one of the leading causes of food-borne salmonellosis in humans. Poultry is the single largest reservoir, and the consumption of incorrectly processed chicken meat and egg products is the major source of infection. Since 2006, the use of antibiotics as growth promoters has been banned in the European Union, and the dietary inclusion of ß-galactomannans (ßGM) has become a promising strategy to control and prevent intestinal infections. The aim of this study was to investigate the effect of various ßGM-rich products on intestinal morphology in chickens challenged with Salmonella Enteritidis. To assess this effect, a total of 280 male Ross 308 chickens were studied (40 animals per treatment housed in 5 cages). There were 7 treatments, including controls: uninoculated birds fed the basal diet (negative control) and inoculated birds fed the basal diet (positive control) or the basal diet supplemented with Salmosan (1 g/kg), Duraió gum (1 g/kg), Cassia gum (1 g/kg), the cell walls of Saccharomyces cerevisiae (0.5 g/kg), or the antibiotic colistine (0.8 g/kg). The birds were fed these diets from the d 1 to 23, except the animals in the colistine group, which were fed the diet containing the antibiotic only from d 5 to 11. The inoculated animals were orally infected on d 7 with 10(8) cfu of Salmonella Enteritidis. Bird performance per replicate was determined for the whole study period (23 d), and the distal ileum and cecal tonsil of 5 animals per treatment (1 animal per replicate) were observed at different magnification levels (scanning electron, light, and laser confocal microscopy). In the images corresponding to the treatments containing ßGM we observed more mucus, an effect that can be associated with the observation of more goblet cells. Moreover, the images also show fewer M cells, which are characteristic of infected animals. Regarding the morphometric parameters, the animals that received Duraió and Cassia gums show greater (P = 0.001 and P = 0.016, respectively) villus length compared with the animals in the positive control, thus indicating the capacity of these products to increase epithelial surface area. However, no effect (P > 0.05) on microvillus dimensions was detected. In conclusion, the results obtained indicating the beneficial effects of these ßGM on intestinal morphology give more evidence of the positive effects of these supplements in poultry nutrition.

Establishment of an in vitro photoassay using THP-1 cells and IL-8 to discriminate photoirritants from photoallergens.

At present, there are no in vivo or in vitro methods developed which has been adopted by regulatory authorities to assess photosensitization induced by chemicals. Recently, we have proposed the use of THP-1 cells and IL-8 release to identify the potential of chemicals to induce skin sensitization. Based on the assumption that sensitization and photosensitization share common mechanisms, the aim of this work was to explore the THP-1 model as an in vitro model to identify photoallergenic chemicals. THP-1 cells were exposed to 7 photoallergens and 3 photoirritants and irradiated with UVA light or kept in dark. Non phototoxic allergens or irritants were also included as negative compounds. Following 24h of incubation, cytotoxicity and IL-8 release were measured. At subtoxic concentrations, photoallergens produced a dose-related increase in IL-8 release after irradiation. Some photoirritants also produced a slight increase in IL-8 release. However, when the overall stimulation indexes of IL-8 were calculated for each chemical, 6 out of 7 photoallergens tested reached a stimulation index above 2, while the entire set of negative compounds had stimulation indexes below 2. Our data suggest that this assay may become a useful cell-based in vitro test for evaluating the photosensitizing potential of chemicals.

[Viscosity changes in thickened water due to the addition of highly prescribed drugs in geriatrics]. / Cambios en la viscosidad del agua con espesantes por la adición de fármacos altamente prescritos en geriatría.

INTRODUCTION: Dysphagia is a swallowing disorder with a high incidence in the geriatric patient related with an increased risk for undernutrition and pneumonia due to bronchial aspiration. In this condition, it is usual to add commercial thickeners in liquids, as well as the addition of drugs in this mixture to improve their administration. However, there are no studies regarding the possible change in viscosity produced by their addition. OBJECTIVES: To assess the change in viscosity of water thickened with commercial products by adding the drugs frequently used in elderly patients. METHODS: Samples of water mixed with the commercial thickener Resource (modified corn starch) or Nutilis (modified corn starch, maltodextrin, and gums: tara, xhantan, and guar) to achieve an intermediate consistence as "honey". The viscosity of these samples was measured as well as for similar samples to which one of the following drugs was added: galantamine, rivastigmin, ciprofloxacin, cholecalciferol, memantine, fosfomycin, calcium, and amoxicillin/clavulanic acid. RESULTS: In the samples with Resource thickener we observed decreased viscosity by adding galantamine, memantine, fosfomycin or calcium, and increased viscosity with amoxicillin/clavulanic acid. The viscosity of the samples with Nutilis® decreased with galantamine, rivastigmine, amoxicillin/clavulanic acid, fosfomycin and calcium. CONCLUSION: The viscosity of water with commercial thickeners may be affected by some drugs or their preservatives, which may influence the swallowing capability. It is recommended to perform further in vitro and in vivo studies in order to adjust these formulations if necessary.

Partial Na+ dependence of DL-2-hydroxy-4-(methylthio)butanoic acid uptake in the chicken small intestine.

Methionine hydroxy analogue DL-2-hydroxy-(4-methylthio)butanoic acid (HMTBA) is commonly used as a supplemental source of Met in commercial animal diets. To better understand the uptake of this analogue by the chicken intestine, the aim of the present study was to assess the contribution of Na+ gradient on HMTBA accumulation in everted sacs of the chicken small intestine (duodenum, jejunum, and ileum). In the presence of an H+ gradient, uptake was lower in the absence of Na+ along the chicken small intestine, although no significant differences were detected in the duodenum. In contrast, in the absence of an H+ gradient, no significant differences were detected between the 2 Na+ conditions. In conclusion, the observed relationship between Na+ and H+ dependence indicates the participation of the apical Na+/H+ exchanger in HMTBA uptake in the chicken small intestine.

Conversion of the methionine hydroxy analogue DL-2-hydroxy-(4-methylthio) butanoic acid to sulfur-containing amino acids in the chicken small intestine.

dl-Methionine or its corresponding hydroxy analogue, DL-2-hydroxy-(4-methylthio) butanoic acid (DLHMB), are commonly added to commercial animal diets to satisfy the TSAA requirement. The utilization of DLHMB as a supplementary source of Met begins with its conversion to L-Met via a 2-step mediated process. L-Methionine can then be transsulfurated to L-Cys, which, in turn, can be catabolized to taurine (TAU). In the present study, the capacity of the chicken small intestine to convert DLHMB to L-Met and to use this amino acid as a source for L-Cys and TAU production was evaluated. The appearance of Met in the serosal compartment of everted sacs incubated with DLHMB is higher in the presence of an H(+) gradient (mucosal pH 5.5 vs. 7.4). Serosal Cys and TAU concentration was compared in everted sacs incubated at a mucosal pH of 5.5 with DLHMB or L-Met, and the results show significantly higher values after incubation with the hydroxy analogue. Regional comparisons indicate no significant differences in the appearance of serosal Met and Cys, although lower values were obtained for TAU in the duodenum than in the jejunum and ileum. The profile of non-S amino acids was also determined and revealed no significant differences between DLHMB- and L-Met-incubated sacs. In conclusion, Cys and TAU content in chicken enterocytes is higher when DLHMB is used as a Met source.

Oligomers are not the limiting factor in the absorption of DL-2-hydroxy-4-(methylthio)butanoic acid in the chicken small intestine.

The methionine hydroxy analogue DL-2-hydroxy-4-(methylthio)butanoic acid (HMB) is commonly used as a supplemental source of methionine in commercial animal diets. The HMB free acid is an aqueous solution that contains 88% product in an equilibrium mixture of monomer, dimer, and polymeric compounds. The present study examines whether the presence of these nonmonomeric forms reduces the absorption of the hydroxy analogue in the chicken small intestine. In vivo and in vitro methodologies were used to compare the intestinal absorption of an HMB product containing mainly monomer (HMB-PCM) with commercial HMB. The results from the in vivo perfusion of the jejunum showed no significant differences between the 2 hydroxy analogue sources in monomer absorption from the intestinal lumen, tissue accumulation, or plasma concentration. The results also indicate that the nonmonomeric forms are hydrolyzed during perfusion. Moreover, monomer tissue accumulation in everted sacs showed no significant differences between substrates, either in the presence or in the absence of a H+-gradient; a higher value was observed in the jejunum and ileum in comparison with the duodenum. Similarly, serosal appearance in H+-gradient conditions did not differ significantly between substrates, and it showed the same regional profile as in tissue accumulation. Oligomer hydrolysis was confirmed in vitro without significant differences between segments. In conclusion, the presence of nonmonomeric forms is not a limiting factor in HMB absorption, apparently because of the hydrolytic capacity of intestinal mucosa, as confirmed by experiments in vivo and in vitro.