The comparative performance of a custom Canine NanoString® panel on FFPE and snap frozen liver biopsies.

Formalin-Fixed Paraffin Embedded (FFPE) biopsies would provide a critical mass of cases to allow investigation of canine liver disease, however their use is often limited by challenges typically associated with transcriptomic analysis. This study evaluates the capability of NanoString® to measure the expression of a broad panel of genes in FFPE liver samples. RNA was isolated from matched histopathologically normal liver samples using FFPE (n = 6) and snap frozen in liquid nitrogen (n = 6) and measured using a custom NanoString® panel. Out of the 40 targets on the panel, 27 and 23 targets were above threshold for non-diseased snap frozen and FFPE tissue respectively. The binding density and total counts were significantly reduced in the FFPE samples relative to the snap frozen samples (p = 0.005, p = 0.01, respectively), confirming a reduction in sensitivity. The concordance between the snap frozen and FFPE samples was high, with correlations (R) ranging between 0.88 and 0.99 between the paired samples. An additional 14 immune-related targets, undetectable the non-diseased FFPE liver, were above threshold when the technique was applied to a series of diseased samples, further supporting their inclusion on this panel. This use of NanoString® based analysis opens up huge opportunity for retrospective evaluation of gene signatures in larger caseloads through harnessing the capacity of archived FFPE samples This information used alongside clinical and histological data will not only afford a way to explore disease etiopathogenesis, it may also offer insight into sub-types of liver disease in dogs, which cannot be discerned using more traditional diagnostic methods.

In Vitro Evaluation of Brown Seaweed Laminaria spp. as a Source of Antibacterial and Prebiotic Extracts That Could Modulate the Gastrointestinal Microbiota of Weaned Pigs.

Laminaria spp. and their extracts have preventative potential as dietary supplements during weaning in pigs. The first objective of this study was to evaluate increasing concentrations of four whole seaweed biomass samples from two different Laminaria species harvested in two different months in a weaned pig faecal batch fermentation assay. Particularly, February and November whole seaweed biomass samples of L. hyperborea (LHWB-F and LHWB-N) and L. digitata (LDWB-F and LDWB-N) were used. In the next part of the study, the increasing concentrations of four extracts produced from L. hyperborea (LHE1-4) and L. digitata (LDE1-4) were evaluated in individual pure-culture growth assays using a panel of beneficial and pathogenic bacterial strains (second objective). The LHE1-4 and LDE1-4 were obtained using different combinations of temperature, incubation time and volume of solvent within a hydrothermal-assisted extraction methodology (E1-4). In the batch fermentation assay, the L. hyperborea biomass samples, LHWB-F and LHWB-N, lowered Bifidobacterium spp. counts compared to the L. digitata biomass samples, LDWB-F and LDWB-N (p < 0.05). LHWB-F and LDWB-N reduced Enterobacteriaceae counts (p < 0.05). LHWB-F and LDWB-F were selected as the most and least promising sources of antibacterial extracts from which to produce LHE1-4 and LDE1-4. In the pure-culture growth assays, E1- and E4-produced extracts were predominantly associated with antibacterial and bifidogenic activities, respectively. LHE1 reduced both Salmonella Typhimurium and Enterotoxigenic Escherichia coli with LDE1 having a similar effect on both of these pathogenic strains, albeit to a lesser extent (p < 0.05). Both LHE1 and LDE1 reduced B. thermophilum counts (p < 0.05). LDE4 exhibited strong bifidogenic activity (p < 0.05), whereas LHE4 increased Bifidobacterium thermophilum and Lactiplantibacillus plantarum counts (p < 0.05). In conclusion, antibacterial and bifidogenic extracts of Laminaria spp. were identified in vitro with the potential to alleviate gastrointestinal dysbiosis in newly weaned pigs.

The effects of dietary supplementation with mushroom or selenium enriched mushroom powders on the growth performance and intestinal health of post-weaned pigs.

BACKGROUND: There is an urgent need to identify natural bioactive compounds that can enhance gastrointestinal health and promote pig growth performance in the absence of pharmacological levels of zinc oxide (ZnO). The objectives of this study were to: 1) compare the effects of mushroom powder supplemented with inorganic selenium (inSeMP) to mushroom powder enriched with organic selenium (orgSeMP) to pharmacological levels of ZnO on growth performance and faecal scores (FS) for the first 21 d post-weaning (Period 1); and 2) compare the molecular and microbial effects of inSeMP and orgSeMP in these pigs on d 39 post-weaning (Period 2). METHODS: In Period 1, pigs (3 pigs/pen; 8 pens/treatment) were assigned to: (1) basal diet (control); (2) basal diet + zinc oxide (ZnO) (3100 mg/kg d 1-14, 1550 mg/kg d 15-21); (3) basal diet + mushroom powder supplemented with inorganic selenium (inSeMP) containing selenium (selenite) content of 0.3 mg/kg feed; (4) basal diet + mushroom powder enriched with organic selenium (orgSeMP) containing selenium (selenocysteine) content of 0.3 mg/kg feed. Mushroom powders were included at 6.5 g/kg of feed. RESULTS: In Period 1, there was no effect of diets on average daily gain (ADG) and gain:feed (G:F) ratio (P > 0.05). The orgSeMP supplemented pigs had a lower average daily feed intake (ADFI) compared to all other groups (P < 0.05). The ZnO supplemented pigs had reduced FS compared to the basal and mushroom group, while the orgSeMP supplemented pigs had lower FS compared to the basal group during the 21 d experimental period (P < 0.05). In Period 2, there was no effect of diets on ADFI, ADG and G:F ratio (P > 0.05). The orgSeMP supplementation increased the caecal abundance of bacterial members of the Firmicutes and Bacteroidetes phylum, including Lactobacillus, Agathobacter, Roseburia, and Prevotella and decreased the abundance of Sporobacter compared to the basal group, while inSeMP increased the caecal abundance of Prevotella and decreased the caecal abundance of Sporobacter compared to the basal group (P < 0.05). Dietary supplementation with inSeMP increased expression of TLR4 and anti-inflammatory cytokine gene IL10 and decreased nutrient transporter gene FABP2 compared to the orgSeMP group (P < 0.05). CONCLUSION: OrgSeMP is a novel and sustainable way to incorporate selenium and ß-glucans into the diet of weaned pigs whilst improving FS and modulating the caecal microbiota.

Maternal supplementation with a casein hydrolysate and yeast beta-glucan from late gestation through lactation improves gastrointestinal health of piglets at weaning.

Improving maternal nutrition during pregnancy/lactation is a promising strategy to maximise the intestinal health of piglets undergoing abrupt weaning under commercial production conditions. This experiment investigated the effects of maternal supplementation of a casein hydrolysate and yeast ß-glucan (CH-YBG) from day 83 of gestation until weaning (day 28) on sow faecal microbial populations and measures of piglet gastrointestinal health parameters at weaning. Sows (n = 10 sows/group) were assigned to: (1) control diet, and (2) control diet + CH-YBG. Maternal supplementation increased the abundance of the phylum Firmicutes, including members Lactobacillus in the sows faeces, with a concomitant increase in the caecal abundance of Lactobacillus in the weaned piglets compared to the controls. Piglets weaned from the supplemented sows had increased villus height in the duodenum (P < 0.05) and increased villus height to crypt depth ratio in the jejunum, as well as a decreased expression of the proinflammatory cytokine genes (IL6/TNF/TGFB), the tight junction gene CLDN3 and the mucin gene MUC2 in the duodenum/jejunum compared to the controls (P < 0.05). In conclusion, maternal CH-YBG supplementation during pregnancy/lactation improved microbial, structural, and inflammatory measures of gastrointestinal health of piglets at weaning. This is a promising strategy to alleviate the challenges that occur with early abrupt weaning in commercial pig production.

Maternal and/or direct supplementation with a combination of a casein hydrolysate and yeast ß-glucan on post-weaning performance and intestinal health in the pig.

A 2 × 2 factorial experiment was conducted to investigate the effect of maternal supplementation from day 83 of gestation and/or direct supplementation from weaning of a bovine casein hydrolysate plus a yeast ß-glucan (CH-YBG) on pig performance and intestinal health on day ten post-weaning. Twenty cross bred gilts (Large White × Landrace) were randomly assigned to one of two dietary groups (n = 10 gilts/group): basal diet (basal sows) and basal diet supplemented with CH-YBG (supplemented sows) from day 83 of gestation until weaning (2g/sow/day). At weaning, 120 pigs (6 pigs/sow) were selected. The two dam groups were further divided, resulting in four experimental groups (10 replicates/group; 3 pigs/pen) as follows: 1) BB (basal sows + basal pigs); 2) BS (basal sows + supplemented pigs); 3) SB (supplemented sows + basal pigs); 4) SS (supplemented sows + supplemented pigs). Supplemented pigs were offered 0.5g CH-YBG/kg of feed for 10 days post-weaning. On day 10 post-weaning, 1 pig/pen was humanely sacrificed and samples were taken from the gastrointestinal tract for analysis. Pigs weaned from supplemented sows (SS, SB) had reduced faecal scores and incidence of diarrhoea (P<0.05) compared to pigs weaned from basal sows (BB, BS), with SS pigs not displaying the transient rise in faecal scores seen in the other three groups from day 3 to day 10 post-weaning (P<0.05). Pigs weaned from supplemented sows had reduced feed intake (P<0.05), improved feed efficiency (P<0.05), increased butyrate concentrations (P<0.05), increased abundance of Lactobacillus (P<0.05) and decreased abundance of Enterobacteriaceae and Campylobacteraceae (P<0.05) compared to pigs weaned from basal sows. In conclusion, maternal supplementation increased the abundance of Lactobacillus and decreased the abundance of Enterobacteriaceae and Campylobacteraceae while also increasing butyrate concentrations. The combination of maternal and direct supplementation led to pigs having the lowest faecal scores compared to all other groups.

Potential of a fucoidan-rich Ascophyllum nodosum extract to reduce Salmonella shedding and improve gastrointestinal health in weaned pigs naturally infected with Salmonella.

BACKGROUND: Dietary supplementation with a fucoidan-rich Ascophyllum nodosum extract (ANE), possessing an in vitro anti-Salmonella Typhimurium activity could be a promising on-farm strategy to control Salmonella infection in pigs. The objectives of this study were to: 1) evaluate the anti-S. Typhimurium activity of ANE (containing 46.6% fucoidan, 18.6% laminarin, 10.7% mannitol, 4.6% alginate) in vitro, and; 2) compare the effects of dietary supplementation with ANE and Zinc oxide (ZnO) on growth performance, Salmonella shedding and selected gut parameters in naturally infected pigs. This was established post-weaning (newly weaned pig experiment) and following regrouping of post-weaned pigs and experimental re-infection with S. Typhimurium (challenge experiment). RESULTS: In the in vitro assay, increasing ANE concentrations led to a linear reduction in S. Typhimurium counts (P <  0.05). In the newly weaned pig experiment (12 replicates/treatment), high ANE supplementation increased gain to feed ratio, similar to ZnO supplementation, and reduced faecal Salmonella counts on d 21 compared to the low ANE and control groups (P <  0.05). The challenge experiment included thirty-six pigs from the previous experiment that remained on their original dietary treatments (control and high ANE groups with the latter being renamed to ANE group) apart from the ZnO group which transitioned onto a control diet on d 21 (ZnO-residual group). These dietary treatments had no effect on performance, faecal scores, Salmonella shedding or colonic and caecal Salmonella counts (P > 0.05). ANE supplementation decreased the Enterobacteriaceae counts compared to the control. Enterobacteriaceae counts were also reduced in the ZnO-residual group compared to the control (P <  0.05). ANE supplementation decreased the expression of interleukin 22 and transforming growth factor beta 1 in the ileum compared to the control (P <  0.05). CONCLUSIONS: ANE supplementation was associated with some beneficial changes in the composition of the colonic microbiota, Salmonella shedding, and the expression of inflammatory genes associated with persistent Salmonella infection.

Evaluation of the in vitro effects of the increasing inclusion levels of yeast ß-glucan, a casein hydrolysate and its 5 kDa retentate on selected bacterial populations and strains commonly found in the gastrointestinal tract of pigs.

Previously, the 5 kDa retentate (5kDaR) of a casein hydrolysate (CH) and yeast ß-glucan (YBG) were identified as promising anti-inflammatory dietary supplements for supporting intestinal health in pigs post-weaning. However, their direct effects on intestinal bacterial populations are less well-known. The main objectives of this study were to determine if the increasing concentrations of the CH, 5kDaR and YBG individually, can: (1) alter the bacterial and short-chain fatty acid profiles in a weaned pig faecal batch fermentation assay, and (2) directly influence the growth of selected beneficial (Lactobacillus plantarum, L. reuteri, Bifidobacterium thermophilum) and pathogenic (Enterotoxigenic Escherichia coli, Salmonella Typhimurium) bacterial strains in individual pure culture growth assays. The potential of CH as a comparable 5kDaR substitute was also evaluated. The 5kDaR increased lactobacilli counts and butyrate concentration in the batch fermentation assay (P < 0.05) and increased L. plantarum (linear, P < 0.05), L. reuteri (quadratic, P < 0.05) and B. thermophilum (linear, P < 0.05) counts and reduced S. typhimurium (quadratic, P = 0.058) counts in the pure culture growth assays. CH increased butyrate concentration (P < 0.05) in the batch fermentation assay. YBG reduced Prevotella spp. counts (P < 0.05) and butyrate concentration (P < 0.05) in the batch fermentation assay. Both CH and YBG had no major effects in the pure culture growth assays. In conclusion, the 5kDaR had the most beneficial effects associated with increased counts of Lactobacillus and Bifidobacterium genera and butyrate production and reduced S. typhimurium counts in vitro indicating its potential to promote gastrointestinal health.

Evaluation of the Antibacterial and Prebiotic Potential of Ascophyllum nodosum and Its Extracts Using Selected Bacterial Members of the Pig Gastrointestinal Microbiota.

Ascophyllum nodosum and its extracts are promising antibacterial and prebiotic dietary supplements for pigs. The objectives of this study were to evaluate the effects of the increasing concentrations of: (1) two whole biomass samples of A. nodosum with different harvest seasons, February (ANWB-F) and November (ANWB-N), in a weaned pig faecal batch fermentation assay, and (2) A. nodosum extracts produced using four different extraction conditions of a hydrothermal-assisted extraction methodology (ANE1-4) and conventional extraction methods with water (ANWE) and ethanol (ANEE) as solvent in individual pure culture growth assays using a panel of beneficial and pathogenic bacterial strains. In the batch fermentation assay, ANWB-F reduced Bifidobacterium spp. counts (p < 0.05) while ANWB-N increased total bacterial counts and reduced Bifidobacterium spp. and Enterobacteriaceae counts (p < 0.05). Of the ANE1-4, produced from ANWB-F, ANWE and ANEE that were evaluated in the pure culture growth assays, the most interesting extracts were the ANE1 that reduced Salmonella Typhimurium, enterotoxigenic Escherichia coli and B. thermophilum counts and the ANE4 that stimulated B. thermophilum growth (p < 0.05). In conclusion, the extraction method and conditions influenced the bioactivities of the A. nodosum extracts with ANE1 and ANE4 exhibiting distinct antibacterial and prebiotic properties in vitro, respectively, that merit further exploration.

The Effects of the Marine-Derived Polysaccharides Laminarin and Chitosan on Aspects of Colonic Health in Pigs Challenged with Dextran Sodium Sulphate.

This study examined the effects of dietary supplementation with laminarin or chitosan on colonic health in pigs challenged with dextran sodium sulphate (DSS). Weaned pigs were assigned to: (1) a basal diet (n = 22); (2) a basal diet + laminarin (n = 10); and (3) a basal diet + chitosan (n = 10). On d35, the basal group was split, creating four groups: (1) the basal diet (control); (2) the basal diet + DSS; (3) the basal diet + laminarin + DSS; and (4) the basal diet + chitosan + DSS. From d39-42, the pigs were orally challenged with DSS. On d44, colonic tissue/digesta samples were collected. The basal DSS group had reduced growth, higher pathology score and an increased expression of MMP1, IL13 and IL23 compared with the controls (p < 0.05); these parameters were similar between the DSS-challenged groups (p > 0.05). In the basal DSS group, the relative abundance of beneficial taxa including Prevotella and Roseburia were reduced while Escherichia/Shigella were increased, compared with the controls (p < 0.05). The relative abundance of Escherichia/Shigella was reduced and the molar proportions of acetate were increased in the laminarin DSS group compared with the basal DSS group (p < 0.01), suggesting that laminarin has potential to prevent pathogen proliferation and enhance the volatile fatty acid profile in the colon in a porcine model of colitis.

Anti-Inflammatory Effects of Pomegranate Peel Extracts on In Vitro Human Intestinal Caco-2 Cells and Ex Vivo Porcine Colonic Tissue Explants.

The aim of this study was to determine the anti-inflammatory potential of pomegranate peel extracts (PPE) prepared from waste material of pomegranate juice production both in vitro on Caco-2 cells and ex vivo using porcine colonic tissue explants. Caco-2 cells were stimulated in vitro by TNF and colonic tissue explants were stimulated ex vivo with lipopolysaccharide (LPS). Both tissues were co-treated with PPE at 0, 1.0, 2.5, 5.0, 10 and 25 µg/mL. The secretion of CXCL8 in the supernatant of both experiments was determined by enzyme linked immunosorbent assay (ELISA) and the relative expression of inflammatory cytokines were evaluated in the colonic tissue by quantitative polymerase chain reaction (QPCR). The 2.5 to 25 µg/mL of PPE suppressed CXCL8 (p < 0.001) in the Caco-2 cells, whereas CXCL8 production was suppressed by only 5 and 25 µg/mL (p < 0.01) of PPE in the colonic explants. The 5 µg/mL of PPE also suppressed the expression of IL1A (p < 0.05), IL6 (p < 0.01) and CXCL8 (p < 0.05) in LPS challenged colonic tissues compared to controls. In conclusion, the 5 µg/mL of PPE consistently elicits strong anti-inflammatory activity. These results support the potential of bioactive compounds from the waste peel of pomegranate in terms of their anti-inflammatory activity in cells and tissues of the gastrointestinal tract.

The application of transcriptomic data in the authentication of beef derived from contrasting production systems.

BACKGROUND: Differences between cattle production systems can influence the nutritional and sensory characteristics of beef, in particular its fatty acid (FA) composition. As beef products derived from pasture-based systems can demand a higher premium from consumers, there is a need to understand the biological characteristics of pasture produced meat and subsequently to develop methods of authentication for these products. Here, we describe an approach to authentication that focuses on differences in the transcriptomic profile of muscle from animals finished in different systems of production of practical relevance to the Irish beef industry. The objectives of this study were to identify a panel of differentially expressed (DE) genes/networks in the muscle of cattle raised outdoors on pasture compared to animals raised indoors on a concentrate based diet and to subsequently identify an optimum panel which can classify the meat based on a production system. RESULTS: A comparison of the muscle transcriptome of outdoor/pasture-fed and Indoor/concentrate-fed cattle resulted in the identification of 26 DE genes. Functional analysis of these genes identified two significant networks (1: Energy Production, Lipid Metabolism, Small Molecule Biochemistry; and 2: Lipid Metabolism, Molecular Transport, Small Molecule Biochemistry), both of which are involved in FA metabolism. The expression of selected up-regulated genes in the outdoor/pasture-fed animals correlated positively with the total n-3 FA content of the muscle. The pathway and network analysis of the DE genes indicate that peroxisome proliferator-activated receptor (PPAR) and FYN/AMPK could be implicit in the regulation of these alterations to the lipid profile. In terms of authentication, the expression profile of three DE genes (ALAD, EIF4EBP1 and NPNT) could almost completely separate the samples based on production system (95 % authentication for animals on pasture-based and 100 % for animals on concentrate- based diet) in this context. CONCLUSIONS: The majority of DE genes between muscle of the outdoor/pasture-fed and concentrate-fed cattle were related to lipid metabolism and in particular ß-oxidation. In this experiment the combined expression profiles of ALAD, EIF4EBP1 and NPNT were optimal in classifying the muscle transcriptome based on production system. Given the overall lack of comparable studies and variable concordance with those that do exist, the use of transcriptomic data in authenticating production systems requires more exploration across a range of contexts and breeds.

Anti-inflammatory effects of a casein hydrolysate and its peptide-enriched fractions on TNFα-challenged Caco-2 cells and LPS-challenged porcine colonic explants.

Bioactive milk peptides are reported to illicit a range of physiological benefits and have been proposed as potential functional food ingredients. The objective of this study was to characterize the anti-inflammatory properties of sodium caseinate (NaCAS), its enzyme hydrolysate (EH) and peptide-enriched fractions (5 kDa retentate [R], 1 kDaR and 1 kDa permeate [P]), both in vitro using a Caco-2 cell line, and also ex vivo using a porcine colonic tissue explant system. Caco-2 cells were stimulated with tumour necrosis factor alpha (TNFα) and co-treated with casein hydrolysates for 24 h. Following this, interleukin (IL)-8 concentrations in the supernatant were measured using enzyme-linked immunosorbent assay. Porcine colonic tissue was stimulated with lipopolysaccharide and co-treated with casein hydrolysates for 3 h. The expression of a panel of inflammatory cytokines was measured using qPCR. While dexamethasone reduced the IL-8 concentration by 41.6%, the 1 kDaR and 1 kDaP fractions reduced IL-8 by 68.7% and 66.1%, respectively, relative to TNFα-stimulated Caco-2 cells (P < 0.05). In the ex vivo system, only the 1 kDaR fraction elicited a decrease inIL1-α,IL1-ß,IL-8,TGF-ß andIL-10 expression (P < 0.05). This study provides evidence that the bioactive peptides present in the 1 kDaR fraction of the NaCAS hydrolysate possess anti-inflammatory properties in vitro and ex vivo. Further in vivo analysis of the anti-inflammatory properties of the 1 kDaR is proposed.

SNP variation in the promoter of the PRKAG3 gene and association with meat quality traits in pig.

BACKGROUND: The PRKAG3 gene encodes the γ3 subunit of adenosine monophosphate activated protein kinase (AMPK), a protein that plays a key role in energy metabolism in skeletal muscle. Non-synonymous single nucleotide polymorphisms (SNPs) in this gene such as I199V are associated with important pork quality traits. The objective of this study was to investigate the relationship between gene expression of the PRKAG3 gene, SNP variation in the PRKAG3 promoter and meat quality phenotypes in pork. RESULTS: PRKAG3 gene expression was found to correlate with a number of traits relating to glycolytic potential (GP) and intramuscular fat (IMF) in three phenotypically diverse F1 crosses comprising of 31 Large White, 23 Duroc and 32 Pietrain sire breeds. The majority of associations were observed in the Large White cross. There was a significant association between genotype at the g.-311A>G locus and PRKAG3 gene expression in the Large White cross. In the same population, ten novel SNPs were identified within a 1.3 kb region spanning the promoter and from this three major haplotypes were inferred. Two tagging SNPs (g.-995A>G and g.-311A>G) characterised the haplotypes within the promoter region being studied. These two SNPs were subsequently genotyped in larger populations consisting of Large White (n = 98), Duroc (n = 99) and Pietrain (n = 98) purebreds. Four major haplotypes including promoter SNP's g.-995A>G and g.-311A>G and I199V were inferred. In the Large White breed, HAP1 was associated with IMF% in the M. longissmus thoracis et lumborum (LTL) and driploss%. HAP2 was associated with IMFL% GP-influenced traits pH at 24 hr in LTL (pHULT), pH at 45 min in LTL (pH(45)LT) and pH at 45 min in the M. semimembranosus muscle (pH(45)SM). HAP3 was associated with driploss%, pHULT pH(45)LT and b* Minolta. In the Duroc breed, associations were observed between HAP1 and driploss% and pHUSM. No associations were observed with the remaining haplotypes (HAP2, HAP3 and HAP4) in the Duroc breed. The Pietrain breed was monomorphic in the promoter region. The I199V locus was associated with several GP-influenced traits across all three breeds and IMF% in the Large White and Pietrain breed. No significant difference in promoter function was observed for the three main promoter haplotypes when tested in vitro. CONCLUSION: Gene expression levels of the porcine PRKAG3 are associated with meat quality phenotypes relating to glycolytic potential and IMF% in the Large White breed, while SNP variation in the promoter region of the gene is associated with PRKAG3 gene expression and meat quality phenotypes.

Cyclooxygenase-2 mRNA expression in equine nonglandular and glandular gastric mucosal biopsy specimens obtained before and after induction of gastric ulceration via intermittent feed deprivation.

OBJECTIVE: To measure the expression of cyclooxygenase-2 (COX-2) mRNA in gastric biopsy specimens serially obtained from horses before, during, and after an 8-day intermittent feed-deprivation trial and to investigate the mucosal location of COX-2. ANIMALS: 9 mixed-breed horses for retrieval of gastric biopsy specimens and 16 additional horses for immunohistochemical analysis. PROCEDURES: Gastric biopsy specimens were obtained from 6 horses; 3 of these horses and 3 more participated in an intermittent feed-deprivation trial 9 weeks later. A quantitative PCR assay was used to determine the amount of COX-2 mRNA in biopsy specimens from nonulcerated and ulcerated gastric mucosa. Immunohistochemical staining of specimens by use of a polyclonal anti-COX-2 antibody was performed on full-thickness postmortem gastric biopsy specimens. RESULTS: COX-2 mRNA was expressed in all glandular gastric mucosal specimens but was only detectable in nonglandular mucosal specimens when ulceration was present or during ulcer healing. Positive staining for COX-2 was present in 12 of 14 nonulcerated glandular mucosal sections. Although such staining was weak or absent in nonulcerated nonglandular sections, stronger staining was evident in regenerating epithelium at the rims of erosions and ulcers. CONCLUSIONS AND CLINICAL RELEVANCE: COX-2 was constitutively present in equine glandular gastric mucosa, although its contribution to mucosal protection remains unclear. Our finding of COX-2 mRNA expression in ulcer margins during healing may support a role for the products of this enzyme in mucosal repair. The potential roles of COX-2 should be considered when COX-2-selective inhibitors are prescribed for horses with gastric ulcers.

Practical classes: a platform for deep learning? Overall context in the first-year veterinary curriculum.

The aim of this study is to evaluate the many practical formats that support the first-year veterinary curriculum. These practical classes are diverse in content and style. They include laboratory-based formats, classes involving live animals and cadavers, classes conducted using computer-aided learning tools, study groups, and information technology training. This preliminary study examines ratings for these practical classes, but also relates these ratings to students' approaches to study with the aim of understanding how a deep learning approach manifests itself in the practical setting. The diverse behaviors and attitudes to practical classes are also evaluated in the light of the approaches to study. A questionnaire that evaluated (1) a total of 24 practical classes, (2) the 52-item Approaches to Study Inventory, and (3) 13 behaviors within and attitudes to practical classes was distributed to 69 first-year veterinary students in their final term. Practical classes that involved live animals and cadavers were rated most positively by this group of students. These ratings, however, did not correlate significantly with the deep or surface learning score. The majority of practical classes where the ratings were found to be associated with deep and surface learning were laboratory-based, although overall these practical classes tended to be rated lower than those involving animals. Ratings did not correlate significantly with the strategic approach. A number of behaviors and attitudes to practical classes were also found to be positively and significantly (p=0.0001) associated with the deep learning approach. This preliminary study indicates that this cohort of veterinary students has an overall positive perception of practical classes that permit contact with live animals or cadavers. Although the perception of laboratory-type practical classes was lower overall, the ratings for these practical classes appeared to be influenced by their deep and surface learning scores. We hypothesize that these approaches influence student engagement with and appreciation of laboratory-type classes, but not of classes involving live animals or cadavers. This would suggest that a different "type" of learning is taking place in these different contexts.

Integrating molecular biology into the veterinary curriculum.

The modern discipline of molecular biology is gaining increasing relevance in the field of veterinary medicine. This trend must be reflected in the curriculum if veterinarians are to capitalize on opportunities arising from this field and direct its development toward their own goals as a profession. This review outlines current applications of molecular-based technologies that are relevant to the veterinary profession. In addition, the current techniques and technologies employed within the field of molecular biology are discussed. Difficulties associated with teaching a subject such as molecular biology within a veterinary curriculum can be alleviated by effectively integrating molecular topics throughout the curriculum, pitching the subject at an appropriate depth, and employing varied teaching methods throughout.

Genetic susceptibility to scrapie in sheep: a clinically relevant theme in veterinary medical education.

RATIONALE FOR THIS STUDY: This article describes and evaluates two molecular biology practical classes based around the theme of genetic susceptibility to scrapie in sheep. These practical classes allow students to experience a range of molecular biology techniques in the context of a clinically based genetic disease. METHODOLOGY: The two molecular biology practical classes described are evaluated in terms of their perceived usefulness to study by first-year veterinary medicine students. The students' ratings are then assessed in relation to the approaches to studying (i.e., deep, strategic, and surface). These dimensions of learning are measured using the 52-item Approaches to Studying Inventory (ASI). RESULTS: The overall ratings from students in relation to both the practical classes were found to be positive. The scrapie genotyping practical was the highest-ranking laboratory-based practical in the first-year curriculum. Ratings in terms of usefulness to studies for both practical classes were found to be significantly higher for students with higher deep learning scores. CONCLUSION: The practical classes described here provide a clinically relevant scenario within which molecular biology concepts and methods can be illustrated to veterinary students. The positive correlation with deep learning is more evident for the scrapie genotyping practical than for the DNA extraction practical. This may reflects the complexity of the former, which is greater both technically and conceptually.

Observations of veterinary medicine students' approaches to study in pre-clinical years.

RATIONALE FOR THIS STUDY: This study has two purposes. The first is to explore an instrument of evaluation of the approaches to study (deep, strategic, and surface) adopted by students in the pre-clinical years of their veterinary degree program. The second is to examine relationships between these approaches and a broad range of further factors deemed relevant to the veterinary medicine context. We envisage that a greater knowledge of how these students learn will aid curriculum reform in a way that will enrich the learning experience of veterinary students. METHODOLOGY: A questionnaire consisting of the 52-question Approaches to Study Inventory (ASI) and an additional 49 questions relating mainly to teaching, assessment, and study skills was distributed to 215 veterinary medicine (MVB) students in their pre-clinical years of study. Factor analysis was used to ensure that the ASI section of the questionnaire maintained previously reported structure. The internal reliability of the approaches measured was tested using Cronbach alpha analysis. The approaches were described as frequency distributions. Associations between the parameters (deep, strategic, and surface) and 49 additional context-specific factors were investigated using loglinear analysis. RESULTS: (1) Factor analysis revealed that the integrity and structure of the instrument in this context was generally comparable to previous studies. (2) The impact of a high workload was evident in the surface approach, with fear of failure becoming a strong motivating factor and syllabus boundness a widely used strategy. (3) Associations made between the approaches and 49 context-specific factors showed strong associations between both workload and lack of prior knowledge with the surface approach. (4) Grades were associated positively with both the deep and strategic approaches but negatively with the surface approach. (5) A range of learning and study skills were associated positively with the deep and strategic approaches and negatively with the surface approach. CONCLUSION: The ASI proved to be a reliable and insightful instrument, highlighting specific surface learning tendencies present in the group as well as a deep learning approach, the pattern of which deviates from previous studies on this subject. This study also confirms the value of some teaching practices as a means of supporting deep learning and perhaps challenging surface learning strategies. The prevalent perception of a high workload is notable, as is its positive association with surface learning.