This experiment was conducted to determine the differences in meat quality (cooking loss and shear force), descriptive sensory characteristics, consumer acceptance, and whole muscle proteomes between normal and Pale, Soft, and Exudative (PSE) broiler breast meat. Male Hubbard × Cobb 500 birds (n = 1,050) were raised in commercial houses. Prior to harvest, a sample of the broilers (n = 900) were subjected to short-term stress (38 °C for 2 h), and the remaining broilers (n = 150) were maintained at control conditions (21 °C for 2 h). From the stressed and control condition broilers, breast samples were characterized by pH24 and L*24 as normal (pH24 5.8-6.2, L*24 45-55) or PSE (pH24 5.4-5.7, L*24 55-65). Normal chicken breast meat had lower shear force values than PSE meat (P < 0.05). Based on sensory descriptive analysis, normal cooked chicken breast was more tender and juicier than PSE breast meat (P < 0.05). Consumer sensory analysis results indicated that 81% of consumer panelists liked normal breast meat whereas 62% of the panelists liked PSE breast meat. Whole muscle proteome profiling identified fifteen differentially abundant proteins (P < 0.05) in normal and PSE meat samples. Actin alpha, myosin heavy chain, phosphoglycerate kinase, creatine kinase M type, beta-enolase, carbonic anhydrase 2, proteasome subunit alpha, pyruvate kinase, and malate dehydrogenase were over-abundant in PSE meat whereas phosphoglycerate mutase-1, alpha-enolase, ATP-dependent 6-phosphofructokinase, and fructose 1, 6-bisphosphatase were over-abundant in normal meat. In addition, normal and PSE broiler breast meat were sampled from commercial plants and evaluated for meat quality attributes (pH, color, cooking loss, and tenderness) and their whole muscle proteome. Normal chicken breast meat had lower shear force values than PSE meat (P < 0.05). Proteome analysis revealed five differentially abundant proteins (P < 0.05) between the normal and PSE chicken breast samples. Glycolytic enzymes (beta-enolase and fructose-bisphosphate aldolase C) were over-abundant in PSE breast meat. Myofibrillar protein (myosin heavy chain) was over-abundant in PSE breast meat. In conclusion, results indicated that differences in proteome abundance could be related to the meat quality differences between normal and PSE breast meat.

The effects of deionized water and PSE pork percentage on the quality of smoked deli ham and retorted pouched ham with and without non-meat adjuncts were evaluated. Product quality was determined through evaluation of water holding capacity, cooked color, protein-protein bind, and sensory quality. A randomized complete block design with either three or four replications was utilized to test treatment effects in three separate experiments. The retorting process showed the potential to reduce the effect of PSE meat on color that is present in raw material and smoked deli ham. In retorted ham, modified food starch and soy protein concentrate reduced (p<0.05) cook loss and starch improved color. Deionized water can be utilized to improve yields (1 %) in smoked deli hams, and 25 % pale pork can be used without negatively affecting (p>0.05) sensory or instrumental quality in a retorted pouched ham product. Modified food starch can also be utilized to increase yields in a retortable-pouched ham without significantly affecting sensory quality.

PURPOSE: Normobaric hyperoxia (NBH) has been shown in animal models of experimental retinal detachment (RD) to effectively prevent photoreceptor degeneration. Furthermore, choroidal hyperpermeability has been implicated in the disease pathophysiology. In this study, we studied the effects of 3-hours of 40% FIO2 NBH on photoreceptor morphology and visual acuity in patients with vision loss associated with active central serous chorioretinopathy (CSCR). MATERIALS and METHODS: A total of 8 patients with active unilateral CSCR received at least one 3-hour NBH (40% FIO2) session. Best corrected visual acuity (BCVA) as well as thickness of the central macula, subretinal fluid (SRF), photoreceptor layer (PL), and outer nuclear layer (ONL) were assessed. RESULTS: In patients with unilateral acute CSCR, 3 hours of 40% FIO2 NBH showed a trend towards improved vision, but no statistical differences were obtained for BCVA, CMT, SRF, PL, or ONL. CONCLUSIONS: Administration of 3-hours of NBH did not induce any measurable anatomic changes in the retina nor any significant changes in visual acuity. These results challenge the hypothesis of choroidal hyperpermeability in CSCR and suggest that additional or alternative pathologies contribute to this disease. / 2022-11-29T00:00:00Z

This thesis is an investigation of two common skin conditions of pigs: exudative epidermitis (EE) and ear necrosis (EN). The cause of exudative epidermitis and risk factors are well understood, however the study was prompted because of reports of treatment failure. A survey of veterinary practitioners (n=15) and pork producers (n=58) was conducted to determine which treatments are commonly used. Amongst farmer respondents topical treatments were often used and in serious cases injectable penicillin G was administered. Thirty farms with a history of EE were visited and skin samples taken from affected pigs. The antimicrobial resistance pattern for isolates of Staphylococcus hyicus and Staphylococcus aureus revealed that almost all isolates were resistant to penicillin G and ampicillin. In addition, certain isolates of S. hyicus as well as S. aureus were shown to possess the mecA gene which is associated with resistance to methicillin. The presence of widespread resistance to penicillin G among staphylococci isolates suggests a reason for poor treatment response. The presence of the mecA gene in staphylococci other than S. aureus recovered from pigs has not been reported before and is of interest from a public health standpoint. A second study investigated EN. The causative agent(s) and the associated risk factors are not well understood. Eleven case farms were visited and skin biopsies and oral swabs taken from pigs in early, mid and late stages of the disease. Bacteriological culturing was performed for staphylococci and spirochetes as well as histological examination of the biopsy samples. Farm-level risk factors were assessed on 14 case farms and 9 control farms. Staphylococci were generally recovered in abundance from the majority of samples but spirochetes were not cultured and only identified microscopically in a small number of tissue samples. Histology revealed that the disease appeared to occur first as a lesion on the epidermal surface that caused tissue damage and led to subsequent invasion of the dermis. This pathogenesis was consistent with the hypothesis that staphylococci colonize the skin surface and produce exfoliating toxins. Ear biting was noted to be commonly present and may be an important contributing factor. / Ontario Pork Animal Health Strategic Initiative Fund Ontario Ministry of Agriculture, Food and Rural Affairs(OMAFRA) Ontario Veterinary College, University of Guelph

Industry surveys indicated that up to 16percent of pork is pale, soft, and exudative (PSE); which has reduced functionality. Recently, the cost of sodium phosphates (SP) has escalated. SPs are used to improve water holding capacity (WHC), increase pH, and retard lipid oxidation. Alkaline non-meat ingredient addition could improve PSE pork functionality and replace SP in pork products. The objective was to examine effects of alkaline solutions on pH, color, WHC, and texture of PSE and normal pork gels. Normal (pH 5.6-5.9) and PSE (pH ≤ 5.4) loins were obtained and homogenized. Treatment solutions were: no added solution (control); double-distilled deionized water (ddW); 0.1, 0.2, and 0.3 pecent(w/v) SP; and 0.1, 0.2, and 0.3M potassium bicarbonate (PB), sodium bicarbonate (SB), potassium carbonate (PC), or sodium carbonate (SC). PSE gels had lighter color, lower pH, WHC, and cook yields, and higher TPA values than normal gels. Control and ddW gels had lower pH, and higher L*, a*, and b* values. As treatment levels increased, gels had higher pH, and lower L*, a*, and b* values. SP gels had lower pH, WHC, cook yields, and higher L*, a*, b*, and TPA values compared to PB, SB, PC, and SC gels. PC and SC gels had higher cook yields than normal control gels and PB and SB gels were intermediate. For both meat types, TPA values improved for PB and SB gels compared to normal control gels, but did not differ from SP gels. As levels of PC and SC increased, gels were softer, less cohesive, chewy, and lower in work 2 than other gels. Cooked PSE gels treated with 0.2 or 0.3M PC or SC were less red and yellow and had cook yields that surpassed normal control and ddW gels. Normal and PSE gels treated with 0.2 or 0.3M PC or SC did not differ in TPA measurements for hardness and work. PSE pork functionality was improved with PC or SC addition to be similar to or higher than normal samples. PC and SC are feasible alternatives to replace SP in pork gel systems without loss of WHC, color, or pH.

O presente estudo teve o objetivo de avaliar o perfil de sensibilidade in vitro de 171 isolados de Staphylococcus hyicus a nove antimicrobianos utilizados na suinocultura. A coleta das amostras foi realizada através de suabes de pele de leitões das fases de maternidade e creche provenientes de casos de epidermite exsudativa. As amostras foram submetidas ao isolamento e identificação e compreenderam dois grupos, classificadas de acordo com o período em que foram coletadas. O primeiro grupo foi formado por amostras históricas (80 isolados) provenientes de estudos anteriores entre 1975 a 1984 no Rio Grande do Sul, e mantidos liofilizados no laboratório de sanidade do Setor de Suínos (FAVET-UFRGS), e o segundo grupo (91 isolados) coletados no ano de 2012 nos estados do Rio Grande do Sul, Santa Catarina, Paraná e Minas Gerais. A realização do teste de susceptibilidade foi feita utilizando a técnica de diluição em ágar conforme protocolo M31-A3 do CLSI. Através de valores de Concentração Inibitória Mínima (CIM), foi obtido o perfil quantitativo de resistência em relação a nove antimicrobianos utilizados na suinocultura. A análise estatística possibilitou a avaliação de mudanças entre os dois grupos de amostras isoladas em diferentes épocas. Os resultados obtidos nesse estudo revelaram que para todas as cepas obtidas os beta-lactâmicos (ceftiofur e amoxicilina) foram os antimicrobianos mais ativos, com CIM para 90% dos isolados históricos (CIM90) de 0.5 μg/mL e 2.0 μg/mL para isolados recentes. A lincomicina, sulfametoxazol e tilmicosina foram os antimicrobianos menos ativos, com CIM90 variando de 128 a 256 μg/mL. O aumento na resistência entre o grupo de amostras históricas e recentes foi observado em seis dos nove antimicrobianos testados (amoxicilina, enrofloxacina, florfenicol, lincomicina, tilmicosina e tiamulina), em particular para a enrofloxacina e tiamulina. No caso do sulfametoxazole e tetraciclina, não foram observadas diferenças significativas na resistência, entretanto altos valores de CIM foram observados nos dois grupos avaliados (p<0,05). / This study was performed to evaluate the "in vitro" susceptibility profile of 171 Staphylococcus hyicus isolates from cases of exudative epidermitis to nine antibiotics used in pig production. Sample consisted of skin swabs from weanling and nursery piglets from farms suspected of exudative epidermitis. Samples were processed for bacterial isolation and identification and divided in two groups, according to the time of collection. The first group comprised historical samples (80 isolates) from previous studies (1975-1984) conducted in the state of Rio Grande do Sul, and stocked lyophilized in Swine Health Lab (FAVET-UFRGS), and the other group (91 isolates) formed by isolates collected in 2012 in the states of Rio Grande do Sul, Santa Catarina, Paraná and Minas Gerais, Brazil. The test was carried out using agar dilution protocol, according to M31-A3 CLSI. Through Minimal Inhibitory Concentrations (MIC) data, analysis was performed to get a quantitative profile of resistance to antimicrobials. Statistical analysis was performed to evaluate changes in resistance between the groups studied. Results showed that beta-lactam (ceftiofur and amoxicillin) were the most active antimicrobials for all strains tested, with the lowest MIC for inhibition of 90% of isolates (MIC90) of 0.5 μg/ml for historical isolates and of 2.0 μg/ml for recent isolates. Lincomycin, sulfamethoxazole and tilmicosin were the less active antimicrobials, with MIC90 varying from 128 to 256 μg/ml. Significant increase in resistance between historical and recent strains was observed for six out of nine antimicrobials tested (amoxicillin, enrofloxacin, florfenicol, lincomycin, tilmicosin and tiamulin), in particular for enrofloxacin e tiamulin. For sulfamethoxazole and tetracycline there was no significant differences in resistance between strains collected in different periods, however high MIC values were observed for these drugs.

O presente estudo teve o objetivo de avaliar o perfil de sensibilidade in vitro de 171 isolados de Staphylococcus hyicus a nove antimicrobianos utilizados na suinocultura. A coleta das amostras foi realizada através de suabes de pele de leitões das fases de maternidade e creche provenientes de casos de epidermite exsudativa. As amostras foram submetidas ao isolamento e identificação e compreenderam dois grupos, classificadas de acordo com o período em que foram coletadas. O primeiro grupo foi formado por amostras históricas (80 isolados) provenientes de estudos anteriores entre 1975 a 1984 no Rio Grande do Sul, e mantidos liofilizados no laboratório de sanidade do Setor de Suínos (FAVET-UFRGS), e o segundo grupo (91 isolados) coletados no ano de 2012 nos estados do Rio Grande do Sul, Santa Catarina, Paraná e Minas Gerais. A realização do teste de susceptibilidade foi feita utilizando a técnica de diluição em ágar conforme protocolo M31-A3 do CLSI. Através de valores de Concentração Inibitória Mínima (CIM), foi obtido o perfil quantitativo de resistência em relação a nove antimicrobianos utilizados na suinocultura. A análise estatística possibilitou a avaliação de mudanças entre os dois grupos de amostras isoladas em diferentes épocas. Os resultados obtidos nesse estudo revelaram que para todas as cepas obtidas os beta-lactâmicos (ceftiofur e amoxicilina) foram os antimicrobianos mais ativos, com CIM para 90% dos isolados históricos (CIM90) de 0.5 μg/mL e 2.0 μg/mL para isolados recentes. A lincomicina, sulfametoxazol e tilmicosina foram os antimicrobianos menos ativos, com CIM90 variando de 128 a 256 μg/mL. O aumento na resistência entre o grupo de amostras históricas e recentes foi observado em seis dos nove antimicrobianos testados (amoxicilina, enrofloxacina, florfenicol, lincomicina, tilmicosina e tiamulina), em particular para a enrofloxacina e tiamulina. No caso do sulfametoxazole e tetraciclina, não foram observadas diferenças significativas na resistência, entretanto altos valores de CIM foram observados nos dois grupos avaliados (p<0,05). / This study was performed to evaluate the "in vitro" susceptibility profile of 171 Staphylococcus hyicus isolates from cases of exudative epidermitis to nine antibiotics used in pig production. Sample consisted of skin swabs from weanling and nursery piglets from farms suspected of exudative epidermitis. Samples were processed for bacterial isolation and identification and divided in two groups, according to the time of collection. The first group comprised historical samples (80 isolates) from previous studies (1975-1984) conducted in the state of Rio Grande do Sul, and stocked lyophilized in Swine Health Lab (FAVET-UFRGS), and the other group (91 isolates) formed by isolates collected in 2012 in the states of Rio Grande do Sul, Santa Catarina, Paraná and Minas Gerais, Brazil. The test was carried out using agar dilution protocol, according to M31-A3 CLSI. Through Minimal Inhibitory Concentrations (MIC) data, analysis was performed to get a quantitative profile of resistance to antimicrobials. Statistical analysis was performed to evaluate changes in resistance between the groups studied. Results showed that beta-lactam (ceftiofur and amoxicillin) were the most active antimicrobials for all strains tested, with the lowest MIC for inhibition of 90% of isolates (MIC90) of 0.5 μg/ml for historical isolates and of 2.0 μg/ml for recent isolates. Lincomycin, sulfamethoxazole and tilmicosin were the less active antimicrobials, with MIC90 varying from 128 to 256 μg/ml. Significant increase in resistance between historical and recent strains was observed for six out of nine antimicrobials tested (amoxicillin, enrofloxacin, florfenicol, lincomycin, tilmicosin and tiamulin), in particular for enrofloxacin e tiamulin. For sulfamethoxazole and tetracycline there was no significant differences in resistance between strains collected in different periods, however high MIC values were observed for these drugs.

O presente estudo teve o objetivo de avaliar o perfil de sensibilidade in vitro de 171 isolados de Staphylococcus hyicus a nove antimicrobianos utilizados na suinocultura. A coleta das amostras foi realizada através de suabes de pele de leitões das fases de maternidade e creche provenientes de casos de epidermite exsudativa. As amostras foram submetidas ao isolamento e identificação e compreenderam dois grupos, classificadas de acordo com o período em que foram coletadas. O primeiro grupo foi formado por amostras históricas (80 isolados) provenientes de estudos anteriores entre 1975 a 1984 no Rio Grande do Sul, e mantidos liofilizados no laboratório de sanidade do Setor de Suínos (FAVET-UFRGS), e o segundo grupo (91 isolados) coletados no ano de 2012 nos estados do Rio Grande do Sul, Santa Catarina, Paraná e Minas Gerais. A realização do teste de susceptibilidade foi feita utilizando a técnica de diluição em ágar conforme protocolo M31-A3 do CLSI. Através de valores de Concentração Inibitória Mínima (CIM), foi obtido o perfil quantitativo de resistência em relação a nove antimicrobianos utilizados na suinocultura. A análise estatística possibilitou a avaliação de mudanças entre os dois grupos de amostras isoladas em diferentes épocas. Os resultados obtidos nesse estudo revelaram que para todas as cepas obtidas os beta-lactâmicos (ceftiofur e amoxicilina) foram os antimicrobianos mais ativos, com CIM para 90% dos isolados históricos (CIM90) de 0.5 μg/mL e 2.0 μg/mL para isolados recentes. A lincomicina, sulfametoxazol e tilmicosina foram os antimicrobianos menos ativos, com CIM90 variando de 128 a 256 μg/mL. O aumento na resistência entre o grupo de amostras históricas e recentes foi observado em seis dos nove antimicrobianos testados (amoxicilina, enrofloxacina, florfenicol, lincomicina, tilmicosina e tiamulina), em particular para a enrofloxacina e tiamulina. No caso do sulfametoxazole e tetraciclina, não foram observadas diferenças significativas na resistência, entretanto altos valores de CIM foram observados nos dois grupos avaliados (p<0,05). / This study was performed to evaluate the "in vitro" susceptibility profile of 171 Staphylococcus hyicus isolates from cases of exudative epidermitis to nine antibiotics used in pig production. Sample consisted of skin swabs from weanling and nursery piglets from farms suspected of exudative epidermitis. Samples were processed for bacterial isolation and identification and divided in two groups, according to the time of collection. The first group comprised historical samples (80 isolates) from previous studies (1975-1984) conducted in the state of Rio Grande do Sul, and stocked lyophilized in Swine Health Lab (FAVET-UFRGS), and the other group (91 isolates) formed by isolates collected in 2012 in the states of Rio Grande do Sul, Santa Catarina, Paraná and Minas Gerais, Brazil. The test was carried out using agar dilution protocol, according to M31-A3 CLSI. Through Minimal Inhibitory Concentrations (MIC) data, analysis was performed to get a quantitative profile of resistance to antimicrobials. Statistical analysis was performed to evaluate changes in resistance between the groups studied. Results showed that beta-lactam (ceftiofur and amoxicillin) were the most active antimicrobials for all strains tested, with the lowest MIC for inhibition of 90% of isolates (MIC90) of 0.5 μg/ml for historical isolates and of 2.0 μg/ml for recent isolates. Lincomycin, sulfamethoxazole and tilmicosin were the less active antimicrobials, with MIC90 varying from 128 to 256 μg/ml. Significant increase in resistance between historical and recent strains was observed for six out of nine antimicrobials tested (amoxicillin, enrofloxacin, florfenicol, lincomycin, tilmicosin and tiamulin), in particular for enrofloxacin e tiamulin. For sulfamethoxazole and tetracycline there was no significant differences in resistance between strains collected in different periods, however high MIC values were observed for these drugs.

Norrin is a secreted cystine-knot growth factor that plays critical roles in vascular development in the brain, retina, and cochlea, as well as the uterus. Although Norrin is unrelated to the lipid-modified morphogens Wnts, Norrin activates the canonical Wnt/&beta;-catenin pathway by binding to receptor Frizzled4 cysteine-rich domain (Fz4-CRD) and co-receptors of low density lipoprotein receptor related protein 5/6 ectodomain (Lrp5/6-ECD) in conjunction with Tetraspanin-12 (Tspan-12). Like Wnts, Norrin has limited extracellular diffusion properties as a result of associating with heparan sulfate proteoglycans (HSPGs). Mutations lead to inherited disordered retinal vascularization diseases such as Norrie disease, familial exudative vitreoretinopathy and coats' disease. However, the molecular mechanism of how Norrin initiates signalling by engagement with Fz4, Lrp5/6, and HSPGs has remained unresolved. Here, novel strategies for protein production of recombinant human Norrin and Fz4-CRD as well as the complex are developed. The crystal structures of Norrin and its complex with Fz4-CRD, plus complex bound with the heparin mimic sucrose octasulphate, and unliganded structures of Fz4-CRD are presented. These structural data together with biophysical and cellular assays not only reveal the Fz4 and Lrp5/6 binding sites on distinct patches of the Norrin surface, but also indicate the HSPGs binding site on Norrin and Fz4-CRD as well as providing a framework to explain numerous disease-related mutations. Structural comparison with Xenopus Wnt8 in complex with mouse Fz8-CRD provides molecular insights for our understanding of ligand-receptor binding specificity and promiscuity, which has important implications for developing therapeutic strategies against Norrin dependent retinal disorders, and cancers caused by abnormal Wnt signaling.