Performance Responses, Nutrient Digestibility, Blood Characteristics, and Measures of Gastrointestinal Health in Weanling Pigs Fed Protease Enzyme

Although exogenous protease enzymes have been used in poultry diets quite extensively, this has not been the case for pig diets. In general, due to their better gut fermentative capacity and longer transit time, pigs have greater capacity to digest dietary proteins than poultry. However, in early-weaned piglets, the stress brought about by weaning adversely affects the digestion of dietary proteins. Therefore, a study was conducted to determine the effects of a commercial protease enzyme in weanling pigs. Indices of growth, nutrient digestibility, blood profiles, fecal microflora, fecal gas emission and fecal scores were measured during the study. A total of 50 weanling pigs (6.42±0.12 kg) at 28 d of age were randomly assigned to receive 1 of 2 dietary treatments: i) control diet (corn-soy based) with no supplemental protease (CON), and ii) control diet+200 g/ton protease (PROT) for 42 d. A completely randomized design consisting of 2 treatments, 5 replicates, and 5 pigs in each replicate was used. Growth performance in terms of body weight (27.04±0.38 kg vs 25.75±0.39 kg; p0.05) was similar between treatments at d 42. Relative to CON pigs, PROT fed pigs had increased (p<0.05) apparent total tract digestibility (84.66%±0.65% vs 81.21%±1.13% dry matter and 84.02%±0.52% vs 80.47%±1.22% nitrogen) and decreased (p<0.05) NH3 emission (2.0±0.16 ppm vs 1.2±0.12 ppm) in the feces at d 42. Except for a decreased (p<0.05) in blood creatinine level, no differences were observed in red blood cell, white blood cell, lymphocyte, urea nitrogen, and IgG concentrations between treatments. Fecal score and fecal microflora (Lactobacillus and E. coli) were also similar between CON and PROT groups. Overall, the supplementation of protease enzyme in weanling pigs resulted in improved growth rate and nutrient digestibility. Exogenous protease enzyme reduced fecal NH3 emission, thus, potentially serving as a tool in lowering noxious gas contribution of livestock production in the environment

Comportamento de poedeiras criadas a diferentes densidades e tamanhos de grupo em ambiente enriquecido

O objetivo deste trabalho foi determinar diferenças comportamentais entre poedeiras criadas sob diferentes densidades e tamanhos de grupo, em condições de ambiente enriquecido. Foram utilizadas poedeiras Isa Brown com idade entre 30 e 32 semanas alojadas em galpões de escala reduzida e distorcida. As aves foram criadas durante 28 dias, em baias com cama de maravalha, poleiro e ninho. Foram avaliados dois tamanhos de grupos (6 e 12 aves) e duas densidades de criação (774 e 1.440 cm² por ave), em arranjo fatorial com três repetições. Em amostras de vídeo de 15 min, foram registrados as frequências e os tempos de expressão dos comportamentos: arrumar penas, banho de areia, bater asas, beber água, bicar, coçar a cabeça, ciscar, comer, empoleirar, esticar perna, perseguir, sentar e visitar o ninho. Foram observados efeitos significativos dos tratamentos e da interação entre eles. O grupo de seis aves manifestou aumento da frequência de comportamentos que indicam maior frustração das aves, independentemente da densidade. O tamanho de grupo é o fator mais importante para o bem-estar das aves

Tyrosine kinase signalling pathways in pancreatic cancer

Pancreatic cancer (PC) still remains one of the most aggressive and lethal of human cancers, with a lack of prognostic and predictive biomarkers and effective therapeutic treatments contributing to its poor prognosis and high mortality rate. Perturbations in tyrosine kinase signalling are characteristic of many human cancers. A previous mass spectrometry-based phosphoproteomic screen identified, RON, a receptor tyrosine kinase; and SgK223, a pseudokinase that is characterised by substitutions in its kinase domain particularly in the DFG motif that is known to be conserved among active kinases and is critical for kinase catalytic activity, as possible molecular drivers and hence potential therapeutic targets and/or biomarkers for PC. Previous studies show that RON exhibits increased expression during PC progression and that increased RON promotes cell migration and invasion, and gemcitabine resistance in PC cells in pre-clinical experimental models. However prior to this study, the prognostic significance of RON expression in PC was unknown. In this study, RON expression was characterised in three independent cohorts totalling 492 PC patients, and the relationship between RON expression and overall survival with and without gemcitabine treatment were assessed. Collectively, these data showed that RON expression was not associated with survival or adjuvant gemcitabine therapeutic responsiveness in resected PC. However, this does not exclude RON as a potential therapeutic target. Unlike RON, SgK223 has never been directly implicated in PC prior to this study. For investigating SgK223, an overexpression cell line model was established in human pancreatic duct epithelial (HPDE) cells. SgK223 overexpression in HPDE cells resulted in an elongated cellular morphology, enhanced STAT3 tyrosine phosphorylation and transcriptional activity, and increased cell migration and invasion in transwell assays, which were able to be prevented through inhibiting STAT3. Upstream of STAT3, JAK1 phosphorylation also increased, and its inhibition prevented increased STAT3 phosphorylation in SgK223-overexpressing cells. Src, ERK, and AKT, pathways were also assessed, but were not activated by SgK223 overexpression. Collectively, these data identify a role for SgK223 in STAT3-mediated cell invasiveness in PC. Moreover, this study also identifies SgK223 as a potential therapeutic target and/or biomarker particularly for JAK1/STAT3-directed therapies against PC

Cell cycle sensing of oxidative stress in Saccharomyces cerevisiae by oxidation of a specific cysteine residue in the transcription factor Swi6p

Yeast cells begin to bud and enter S phase when growth conditions are favourable during G1 phase. When subjected to some oxidative stresses, cells delay entry at G1 allowing repair of cellular damage. Hence, oxidative stress sensing is coordinated with the regulation of cell cycle. We identified a novel function of the cell-cycle regulator of Saccharomyces cerevisiae, Swi6p, as a redox sensor through its cysteine residue at position 404. When alanine was substituted at this position, the resultant mutant, C404A, was sensitive to several reactive oxygen species and oxidants including linoleic acid hydroperoxide, the superoxide anion and diamide. This mutant lost the ability to arrest in G1 phase upon treatment with lipid hydroperoxide. The Cys404 residue of Swi6p in wild-type cells was oxidised to a sulfenic acid when cells were subjected to linoleic acid hydroperoxide. Mutation of Cys404 to Ala abolished the down-regulation of expression of the G1 cyclin genes CLN1, CLN2, PCL1 and PCL2 that occurred when cells of the wild type were exposed to the lipid hydroperoxide. In conclusion, oxidative stress signaling for cell-cycle regulation occurs through oxidation of the G1/S-speicific transcription factor Swi6p and consequently leads to suppression of the expression of G1-cyclins and delay in cells entering the cell cycle