Influence of processing on starch digestibility and gut morphology in the weaned piglet

To overcome the `post-weaning growth check' commonly seen at weaning, the incorporation of antibiotic growth promoters (AGPs) to the diet has been a useful management tool. Recent legislation within the European Union banning the use of AGPs at sub-therapeutic levels in animal feed means that the quality of dietary ingredients used in weaner diets has assumed a much more fundamental role. In order to improve the availability of starch in the piglet diet, processing of cereals is widely practised. However, descriptions of processing techniques used in many studies are simply referred to by name, with no regard of the precise variables used. In addition, many of the feed materials are simply referred to as `cooked' which gives little indication of nutritional value. Five trials were conducted in order to assess the use of raw and processed cereals on diet component digestion, digesta properties and gut morphology in newly-weaned piglets. The main objective was to examine the use of precisely controlled processing variables, such that starch digestibility was maximised with benefits for the gastrointestinal environment. A second aspect of the programme of work reported was the application of a number of analytical tests commonly used in the field of human food science, to examine the physicochemical properties of starch granules, and the changes they undergo upon processing. Using this approach, a comparison could be made between in-vitro (rheological) results and in-vivo (biological) responses. Trials 1 and 2 examined variability between raw cereals. Wheat, barley, rye and triticale were assessed in Trial 1. Wheat (identical batch), naked oats, whole oats and maize were evaluated in Trial 2. Coefficients of apparent digestibility (CAD) for starch and nitrogen revealed considerable variation between the cereals. In Trial 1, there was a strong trend (P = 0.051) for starch digestion to be highest for the rye diet and lowest for triticale. CAD for starch was not significantly affected by cereal type in Trial 2. Despite having more viscous intestinal digesta than other animals (P = <0.001), pigs fed the rye-based diet did not experience any detrimental effects to animal performance. Trial 3 examined the use of raw wheat, of either hard or soft endosperm texture. From 5 days post-weaning, piglets fed the soft wheat diet had a tendency (P = 0.063) to have higher feed intakes. In addition, pigs fed soft wheat diets had significantly less viscous tract digesta (P = 0.029) than those animals fed the diet based on hard wheat. There was no significant difference in CAD for starch between the two dietary treatments but CAD for nitrogen was found to be significantly higher (P = 0.006) in the distal region of the small intestine for pigs fed the soft wheat diet. The results from Trial 3 suggest that endosperm texture of wheat can have an effect on nutritional value, and that wheat of soft endosperm texture is more beneficial than hard wheat for the young piglet. Trial 4 was a 2x2 factorial study examining wheat endosperm texture (hard vs. soft) and degree of micronisation (high cook vs. low cook). CAD for starch was not affected by endosperm texture, although degree of cook was an important factor with significantly higher starch digestion for the high cook diets, compared to low cook (P = 0.047). The use of micronised wheat lessened the reduction in starch digestibility seen on day 4 post-weaning in the small intestine, compared against the decline seen using raw wheat diets in Trial 3. In summary, Trial 4 demonstrated that micronisation can enhance the nutritional value of wheat for the weaned piglet, with degree of cook, a more significant factor than wheat endosperm texture. Trial 5 assessed wheat endosperm texture (hard vs. soft) and degree of extrusion (high cook vs. low cook). Raw soft wheat was used as a control. Results showed that CAD for starch in the small intestine was noticeably higher than in the other animal trials. Starch digestion was significantly affected by endosperm texture (greater coefficients for soft than hard; P <0.001) and by degree of cook (high SME greater than low SME; P <0.001). The use of extruded wheat diets almost eliminated the drop in starch digestion at the 0.5 intestinal site seen on day 4 post-weaning. Wheat of soft endosperm texture responded better to extrusion processing than hard wheat under the conditions of Trial 5. The use of computer modelling was able to demonstrate a correlation between in-vitro starch parameters and in-vivo starch digestion in the small intestine of the piglet

Equal-magnitude size-weight illusions experienced within and between object categories.

In the size-weight illusion (SWI), small objects feel heavier than larger objects of the same mass. This effect is typically thought to be a consequence of the lifter\u27s expectation that the large object will outweigh the small object, because objects of the same type typically get heavier as they get larger. Here, we show that this perceptual effect can occur across object category, where there are no strong expectations about the correspondence between size and mass. One group of participants lifted same-colored large and small cubes with the same mass as one another, while another group lifted differently-colored large and small cubes with the same mass as one another. The group who lifted the same-colored cubes experienced a robust SWI and initially lifted the large object with more force than the small object. By contrast, the group who lifted the different-colored objects did so with equal initial forces on the first trial, but experienced just as strong an illusion as those who lifted the same-colored objects. These results demonstrate that color cues can selectively influence the application of fingertip force rates while not impacting at all upon the lifter\u27s perception of object weight, highlighting a stark dissociation in how prior information affects perception and action

Influence of processing on starch digestibility and gut morphology in the weaned piglet

To overcome the `post-weaning growth check' commonly seen at weaning, the incorporation of antibiotic growth promoters (AGPs) to the diet has been a useful management tool. Recent legislation within the European Union banning the use of AGPs at sub-therapeutic levels in animal feed means that the quality of dietary ingredients used in weaner diets has assumed a much more fundamental role. In order to improve the availability of starch in the piglet diet, processing of cereals is widely practised. However, descriptions of processing techniques used in many studies are simply referred to by name, with no regard of the precise variables used. In addition, many of the feed materials are simply referred to as `cooked' which gives little indication of nutritional value. Five trials were conducted in order to assess the use of raw and processed cereals on diet component digestion, digesta properties and gut morphology in newly-weaned piglets. The main objective was to examine the use of precisely controlled processing variables, such that starch digestibility was maximised with benefits for the gastrointestinal environment. A second aspect of the programme of work reported was the application of a number of analytical tests commonly used in the field of human food science, to examine the physicochemical properties of starch granules, and the changes they undergo upon processing. Using this approach, a comparison could be made between in-vitro (rheological) results and in-vivo (biological) responses. Trials 1 and 2 examined variability between raw cereals. Wheat, barley, rye and triticale were assessed in Trial 1. Wheat (identical batch), naked oats, whole oats and maize were evaluated in Trial 2. Coefficients of apparent digestibility (CAD) for starch and nitrogen revealed considerable variation between the cereals. In Trial 1, there was a strong trend (P = 0.051) for starch digestion to be highest for the rye diet and lowest for triticale. CAD for starch was not significantly affected by cereal type in Trial 2. Despite having more viscous intestinal digesta than other animals (P = <0.001), pigs fed the rye-based diet did not experience any detrimental effects to animal performance. Trial 3 examined the use of raw wheat, of either hard or soft endosperm texture. From 5 days post-weaning, piglets fed the soft wheat diet had a tendency (P = 0.063) to have higher feed intakes. In addition, pigs fed soft wheat diets had significantly less viscous tract digesta (P = 0.029) than those animals fed the diet based on hard wheat. There was no significant difference in CAD for starch between the two dietary treatments but CAD for nitrogen was found to be significantly higher (P = 0.006) in the distal region of the small intestine for pigs fed the soft wheat diet. The results from Trial 3 suggest that endosperm texture of wheat can have an effect on nutritional value, and that wheat of soft endosperm texture is more beneficial than hard wheat for the young piglet. Trial 4 was a 2x2 factorial study examining wheat endosperm texture (hard vs. soft) and degree of micronisation (high cook vs. low cook). CAD for starch was not affected by endosperm texture, although degree of cook was an important factor with significantly higher starch digestion for the high cook diets, compared to low cook (P = 0.047). The use of micronised wheat lessened the reduction in starch digestibility seen on day 4 post-weaning in the small intestine, compared against the decline seen using raw wheat diets in Trial 3. In summary, Trial 4 demonstrated that micronisation can enhance the nutritional value of wheat for the weaned piglet, with degree of cook, a more significant factor than wheat endosperm texture. Trial 5 assessed wheat endosperm texture (hard vs. soft) and degree of extrusion (high cook vs. low cook). Raw soft wheat was used as a control. Results showed that CAD for starch in the small intestine was noticeably higher than in the other animal trials. Starch digestion was significantly affected by endosperm texture (greater coefficients for soft than hard; P <0.001) and by degree of cook (high SME greater than low SME; P <0.001). The use of extruded wheat diets almost eliminated the drop in starch digestion at the 0.5 intestinal site seen on day 4 post-weaning. Wheat of soft endosperm texture responded better to extrusion processing than hard wheat under the conditions of Trial 5. The use of computer modelling was able to demonstrate a correlation between in-vitro starch parameters and in-vivo starch digestion in the small intestine of the piglet

Work-related physical activity and psychological distress among women in different occupations : a cross-sectional study

BACKGROUND: Recent evidence suggests that work-related physical activity may not have the same mental health benefits as leisure-time physical activity. Further, work-related physical activity is likely to include a variety of different behaviours for people with different occupations. As such, the aim of this study was to determine if occupation type moderated the association between work-related physical activity and psychological distress. METHODS: A randomly selected sample of 1080 women from Melbourne, Australia completed the International Physical Activity Questionnaire (IPAQ) and General Health Questionnaire (GHQ-30), and reported their current occupation. RESULTS: Linear regression analyses indicated that occupation significantly moderated the association between work-related walking and psychological distress (F [8, 55] = 2.26, p = .036). Given evidence of moderation, we fitted linear regression models to test the associations between work-related physical activity and psychological distress for three separate groups; professionals, sales and services workers, and tradespersons. Female tradespersons who engaged in a low (B = - 3.81, p = .006) or high amount of work-related walking (B = - 3.23, p = .029), had significantly lower psychological distress symptoms than those who engaged in no work-related walking. There were no significant associations between work-related physical activity of any intensity and psychological distress for professionals, or sales and service workers. CONCLUSIONS: Given the relationship does not exist across all occupations, work-related physical activity should not be promoted above and beyond leisure-time physical activity. However, walking at work may be important in reducing psychological distress for some people and should therefore, not be discounted

Differences in influenza virus receptors in chickens and ducks: Implications for interspecies transmission

Avian influenza viruses are considered to be key contributors to the emergence of human influenza pandemics. A major determinant of infection is the presence of virus receptors on susceptible cells to which the viral haemagglutinin is able to bind. Avian viruses preferentially bind to sialic acid α2,3-galactose (SAα2,3-Gal) linked receptors, whereas human strains bind to sialic acid α2,6-galactose (SAα2,6-Gal) linked receptors. While ducks are the major reservoir for influenza viruses, they are typically resistant to the effects of viral infection, in contrast to the frequently severe disease observed in chickens. In order to understand whether differences in receptors might contribute to this observation, we studied the distribution of influenza receptors in organs of ducks and chickens using lectin histochemistry with linkage specific lectins and receptor binding assays with swine and avian influenza viruses. Although the intestinal epithelial cells of both species expressed only SAα2,3-Gal receptors, we found widespread presence of both SAα2,6-Gal and SAα2,3-Gal receptors in many organs of both chickens and ducks. Co-expression of both receptors may allow infection of cells with both avian and human viruses and so present a route to genetic reassortment. There was a marked difference in the primary receptor type in the trachea of chickens and ducks. In chicken trachea, SAα2,6-Gal was the dominant receptor type whereas in ducks SAα2,3-Gal receptors were most abundant. This suggests that chickens could be more important as an intermediate host for the generation of influenza viruses with increased ability to bind to SAα2,6-Gal receptors and thus greater potential for infection of humans. Chicken tracheal and intestinal epithelial cells also expressed a broader range of SAα2,3-Gal receptors (both β(1-4)GlcNAc and β(1-3)GalNAc subtypes) in contrast to ducks, which suggests that they may be able to support infection with a broader range of avian influenza viruses

Comparative distribution of human and avian type sialic acid influenza receptors in the pig

<p>Abstract</p> <p>Background</p> <p>A major determinant of influenza infection is the presence of virus receptors on susceptible host cells to which the viral haemagglutinin is able to bind. Avian viruses preferentially bind to sialic acid α2,3-galactose (SAα2,3-Gal) linked receptors, whereas human strains bind to sialic acid α2,6-galactose (SAα2,6-Gal) linked receptors. To date, there has been no detailed account published on the distribution of SA receptors in the pig, a model host that is susceptible to avian and human influenza subtypes, thus with potential for virus reassortment. We examined the relative expression and spatial distribution of SAα2,3-GalG(1-3)GalNAc and SAα2,6-Gal receptors in the major organs from normal post-weaned pigs by binding with lectins <it>Maackia amurensis agglutinins </it>(MAA II) and <it>Sambucus nigra agglutinin </it>(SNA) respectively.</p> <p>Results</p> <p>Both SAα2,3-Gal and SAα2,6-Gal receptors were extensively detected in the major porcine organs examined (trachea, lung, liver, kidney, spleen, heart, skeletal muscle, cerebrum, small intestine and colon). Furthermore, distribution of both SA receptors in the pig respiratory tract closely resembled the published data of the human tract. Similar expression patterns of SA receptors between pig and human in other major organs were found, with exception of the intestinal tract. Unlike the limited reports on the scarcity of influenza receptors in human intestines, we found increasing presence of SAα2,3-Gal and SAα2,6-Gal receptors from duodenum to colon in the pig.</p> <p>Conclusions</p> <p>The extensive presence of SAα2,3-Gal and SAα2,6-Gal receptors in the major organs examined suggests that each major organ may be permissive to influenza virus entry or infection. The high similarity of SA expression patterns between pig and human, in particular in the respiratory tract, suggests that pigs are not more likely to be potential hosts for virus reassortment than humans. Our finding of relative abundance of SA receptors in the pig intestines highlights a need for clarification on the presence of SA receptors in the human intestinal tract.</p

Uptake of synthetic low density lipoprotein by leukemic stem cells — a potential stem cell targeted drug delivery strategy

Chronic Myeloid Leukemia (CML) stem/progenitor cells, which over-express Bcr-Abl, respond to imatinib by a reversible block in proliferation without significant apoptosis. As a result, patients are unlikely to be cured owing to the persistence of leukemic quiescent stem cells (QSC) capable of initiating relapse. Previously, we have reported that intracellular levels of imatinib in primary primitive CML cells (CD34&lt;sup&gt;+&lt;/sup&gt;38&lt;sup&gt;lo/−&lt;/sup&gt;), are significantly lower than in CML progenitor cells (total CD34&lt;sup&gt;+&lt;/sup&gt;) and leukemic cell lines. The aim of this study was to determine if potentially sub-therapeutic intracellular drug concentrations in persistent leukemic QSC may be overcome by targeted drug delivery using synthetic Low Density Lipoprotein (sLDL) particles. As a first step towards this goal, however, the extent of uptake of sLDL by leukemic cell lines and CML patient stem/progenitor cells was investigated. Results with non-drug loaded particles have shown an increased and preferential uptake of sLDL by Bcr-Abl positive cell lines in comparison to Bcr-Abl negative. Furthermore, CML CD34&lt;sup&gt;+&lt;/sup&gt; and primitive CD34&lt;sup&gt;+&lt;/sup&gt;38&lt;sup&gt;lo/−&lt;/sup&gt; cells accumulated significantly higher levels of sLDL when compared with non-CML CD34&lt;sup&gt;+&lt;/sup&gt; cells. Thus, drug-loading the sLDL nanoparticles could potentially enhance intracellular drug concentrations in primitive CML cells and thus aid their eradication

Hospital admissions for vitamin D related conditions and subsequent immune-mediated disease: record-linkage studies

PMCID: PMC3729414The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/11/171. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Rapid death of duck cells infected with influenza: a potential mechanism for host resistance to H5N1

Aquatic birds are the natural reservoir for most subtypes of influenza A, and a source of novel viruses with the potential to cause human pandemics, fatal zoonotic disease or devastating epizootics in poultry. It is well recognised that waterfowl typically show few clinical signs following influenza A infection, in contrast, terrestrial poultry such as chickens may develop severe disease with rapid death following infection with highly pathogenic avian influenza. This study examined the cellular response to influenza infection in primary cells derived from resistant (duck) and susceptible (chicken) avian hosts. Paradoxically, we observed that duck cells underwent rapid cell death following infection with low pathogenic avian H2N3, classical swine H1N1 and ‘classical' highly pathogenic H5N1 viruses. Dying cells showed morphological features of apoptosis, increased DNA fragmentation and activation of caspase 3/7. Following infection of chicken cells, cell death occurred less rapidly, accompanied by reduced DNA fragmentation and caspase activation. Duck cells produced similar levels of viral RNA but less infectious virus, in comparison with chicken cells. Such rapid cell death was not observed in duck cells infected with a contemporary Eurasian lineage H5N1 fatal to ducks. The induction of rapid death in duck cells may be part of a mechanism of host resistance to influenza A, with the loss of this response leading to increased susceptibility to emergent strains of H5N1. These studies provide novel insights that should help resolve the long-standing enigma of host–pathogen relationships for highly pathogenic and zoonotic avian influenza

Small contribution of gold mines to the ongoing tuberculosis epidemic in South Africa: a modeling-based study.

BACKGROUND: Gold mines represent a potential hotspot for Mycobacterium tuberculosis (Mtb) transmission and may be exacerbating the tuberculosis (TB) epidemic in South Africa. However, the presence of multiple factors complicates estimation of the mining contribution to the TB burden in South Africa. METHODS: We developed two models of TB in South Africa, a static risk model and an individual-based model that accounts for longer-term trends. Both models account for four populations - mine workers, peri-mining residents, labor-sending residents, and other residents of South Africa - including the size and prevalence of latent TB infection, active TB, and HIV of each population and mixing between populations. We calibrated to mine- and country-level data and used the static model to estimate force of infection (FOI) and new infections attributable to local residents in each community compared to other residents. Using the individual-based model, we simulated a counterfactual scenario to estimate the fraction of overall TB incidence in South Africa attributable to recent transmission in mines. RESULTS: We estimated that the majority of FOI in each community is attributable to local residents: 93.9% (95% confidence interval 92.4-95.1%), 91.5% (91.4-91.5%), and 94.7% (94.7-94.7%) in gold mining, peri-mining, and labor-sending communities, respectively. Assuming a higher rate of Mtb transmission in mines, 4.1% (2.6-5.8%), 5.0% (4.5-5.5%), and 9.0% (8.8-9.1%) of new infections in South Africa are attributable to gold mine workers, peri-mining residents, and labor-sending residents, respectively. Therefore, mine workers with TB disease, who constitute ~ 2.5% of the prevalent TB cases in South Africa, contribute 1.62 (1.04-2.30) times as many new infections as TB cases in South Africa on average. By modeling TB on a longer time scale, we estimate 63.0% (58.5-67.7%) of incident TB disease in gold mining communities to be attributable to recent transmission, of which 92.5% (92.1-92.9%) is attributable to local transmission. CONCLUSIONS: Gold mine workers are estimated to contribute a disproportionately large number of Mtb infections in South Africa on a per-capita basis. However, mine workers contribute only a small fraction of overall Mtb infections in South Africa. Our results suggest that curtailing transmission in mines may have limited impact at the country level, despite potentially significant impact at the mining level