Gene expression profiling of porcine mammary epithelial cells after challenge with Escherichia coli and Staphylococcus aureus in vitro

Postpartum Dysgalactia Syndrome (PDS) represents a considerable health problem of postpartum sows, primarily indicated by mastitis and lactation failure. The poorly understood etiology of this multifactorial disease necessitates the use of the porcine mammary epithelial cell (PMEC) model to identify how and to what extent molecular pathogen defense mechanisms prevent bacterial infections at the first cellular barrier of the gland. PMEC were isolated from three lactating sows and challenged with heat-inactivated potential mastitis-causing pathogens Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) for 3 h and 24 h, in vitro. We focused on differential gene expression patterns of PMEC after pathogen challenge in comparison with the untreated control by performing microarray analysis. Our results show that a core innate immune response of PMEC is partly shared by E. coli and S. aureus. But E. coli infection induces much faster and stronger inflammatory response than S. aureus infection. An immediate and strong up-regulation of genes encoding cytokines (IL1A and IL8), chemokines (CCL2, CXCL1, CXCL2, CXCL3, and CXCL6) and cell adhesion molecules (VCAM1, ICAM1, and ITGB3) was explicitly obvious post-challenge with E. coli inducing a rapid recruitment and activation of cells of host defense mediated by IL1B and TNF signaling. In contrast, S. aureus infection rather induces the expression of genes encoding monooxygenases (CYP1A1, CYP3A4, and CYP1B1) initiating processes of detoxification and pathogen elimination. The results indicate that the course of PDS depends on the host recognition of different structural and pathogenic profiles first, which critically determines the extent and effectiveness of cellular immune defense after infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0178-z) contains supplementary material, which is available to authorized users.     

THE UTILIZATION OF DRIED GRASS BY EARLY WEANED LAMBS

Three groups of 8 Polled Dorset Iambs were weaned at 8 weeks of age and were fed dried grass, a 50–50 mixture of dried grass and protein-supplemented barley and protein-supplemented barley. All rations were completed. Digestibility trials were also conducted and the effect of level of feed intake on nutrient digestibility investigated. The dried grass resulted in rates of gain comparable to those produced by the pelleted barley ration. Feed conversion efficiency was lowest for the grass and highest for the barley ration. An interaction between the dried grass and barley was observed in nutrient digestibility. Increasing the level of feeding from approximately maintenance to appetite tended to result in slight depressions in the digestibility of energy and protein of all rations. The results suggest that dried grass can be used successfully for intensive feeding of early weaned lambs and little nutritional advantage appears to be gained from combining dried grass with barley.     

MyoD,myogenin and proliferating cell nuclear antigen expression in growing Nile tilapia (Oreochromis niloticus L.)

In the present study, immunohistochemical and morphometric analysis was used to characterize variations in muscle growth performance during muscle fibre recruitment and hypertrophy. As in fisheries, fish were classified into four age stages: alevin 35 days (0.65±0.08 g); juvenile 60 days (13.67±1.35 g); adult 90 days (73.18±4.70 g) and adult 190 days (349.76±34.62 g). The number of nuclei expressing MyoD and myogenin was similar in alevin, juvenile and adult 90 days; however, in adult 190 days, the number of nuclei expressing myogenin was higher than the number expressing MyoD. The number of proliferating cell nuclear antigen‐stained nuclei in each stage was higher than MyoD and myogenin staining with peaks in alevin and adult 90 days. These data suggest that growth per se stimulated cellular proliferation and nuclei accretion of Nile tilapia muscle fibres in alevin, juvenile and adult 90 days. Muscle fibre differentiation was more pronounced in adult 190 days.     

Rheological Behavior of Undeveloped and Developed Wheat Dough

Undeveloped wheat dough is essentially wheat flour that has become fully hydrated without being deformed. The rheological properties of this material were compared to dough (developed dough) made using the standard method involving a farinograph. Flow behavior of undeveloped and developed dough samples made from hard and soft wheat flours were tested using creep tests, frequency sweep oscillatory tests, and temperature sweep oscillatory tests. All experiments showed that the undeveloped dough requires less resistance for deformation than developed dough. The differences are due to the energy input received by the developed dough and the influence of this factor in forming the protein matrix associated with developed dough. To attain a comparable state as the dough made in the farinograph, an energy input must be applied to the undeveloped dough material. Understanding the differences between undeveloped and developed dough may lead to new products, equipment, and processes in the bakery industry.     

Phenotyping of Urochloa humidicola grass hybrids for agronomic and environmental performance in the Piedmont region of the Orinoquian savannas of Colombia

In the low fertility acid soils of the Orinoquian savannas of Colombia, Urochloa humidicola cv. Tully or Humidicola is one of the most widely planted tropical forage grasses for improving livestock productivity. Low nutritional quality of this grass limits sustainable livestock production in this region. In this study, we conducted a phenotypic evaluation under field and greenhouse conditions of one of the first hybrid populations of U. humidicola generated from the forage breeding program of CIAT. Our objective was to identify a set of new hybrids of U. humidicola that combine improved productivity and nutritional quality plus the biological nitrification inhibition (BNI) trait/ability to reduce nitrogen (N) losses via leaching and nitrous oxide (N₂O) emissions. To this end, we tested 118 hybrids (planted in pots) in the greenhouse for over 6 months and measured potential nitrification rates (NR) using soil microcosm incubation. NR values observed ranged from 0.27 to 5.75 mg N-NO₃⁻ kg soil⁻¹ day⁻¹. Later, 12 hybrids with different levels of NR were selected and field-tested in the Orinoquia region over a 4 years period (2013–2017) for dry matter production, nutrition quality (crude protein, in vitro digestibility and fibres content) and NR in each year. In the rainy season of 2018, two hybrids with superior agronomic performance and contrasting field level NR (Uh08/1149 and 0450) were subjected to analysis of soil-borne N₂O emissions after fertilization during 13 days. The NR values recorded were not directly correlated with the forage quality parameters evaluated, however, the two grasses with the lowest NR values were among those with the highest biomass production, crude protein content, and N uptake. The grass hybrid Uh08/1149 and the germplasm accession CIAT 16888 were found as materials with superior forage value, with production of 14.1 and 14.6 tons dry matter ha⁻¹ year⁻¹ (up to 8% higher than the cv. Tully), crude protein of 11.5 and 9.1% per cut (up to 20% higher than the cv. Tully), and N uptake of 31.6 and 25.7 kg N ha⁻¹ cut⁻¹ (up to 30% higher than the cv. Tully). Additionally, these two grasses are likely to exhibit high-BNI ability, with potential to improve N use efficiency in managed pastures.     

Identification and quantification of phenolic compounds in grapes by HPLC-PDA-ESI-MS on a semimicro separation scale

Reversed phase high performance liquid chromatography (RP-HPLC) on a semimicro separation scale was employed to develop a straightforward method for the simultaneous separation, identification, and quantification of phenolic compounds occurring in whole berries of Vitis vinifera, which comprise phenolic acids, flavonols, catechins, stilbenes, and anthocyanins. A C-18 narrow bore column of 150 x 2.0 mm I.D. and a semimicro photodiode array detector (PDA) cell of 2.5 microL, in conjunction with a mass spectrometry detector equipped with an electrospray ionization source (ESI-MS) to confirm peak identification, were employed. The C-18 narrow bore column was eluted by a multisegment gradient of increasing concentration of acetonitrile in water-formic acid solution that was optimized on the basis of the results of a study carried out to evaluate the influence of mobile phase composition and gradient shape on separation performance and detection sensitivity by ESI-MS. The identification of individual phenolic compounds was performed on the basis of their retention times and both UV-visible and mass spectra, acquired by a mass spectrometer (MS) equipped with an electrospray ionization (ESI) source, employed in conjunction with the PDA detector. Libraries comprising retention times, UV-visible, and mass spectra for major phenolic compounds expected in grape berries were made by subjecting solutions of each phenolic standard to the optimized RP-HPLC method. Quantification of individual compounds was performed by the external standard method using a six point regression graph of the UV-visible absorption data collected at the wavelength of maximum absorbance of each analyte determined by the PDA spectra. The RP-HPLC method was validated in terms of linearity of calibration graphs, limits of detection, limits of quantification, repeatability, and accuracy, which was evaluated by a recovery study. The developed method was successfully applied to identify the phenolic compounds occurring in the whole berries of nine red and one white grape of different varieties of Vitis vinifera, comprising some autochthonous varieties of south Italy such as Aglianico, Malvasia Nera, Uva di Troia, Negroamaro, Primitivo, and Susumaniello. Large differences in the content of phenolic compounds was found in the investigated grape varieties. As expected, only glycosilated flavonols were quantified, and the total amount of these compounds was higher in the whole berries of red grapes than in the white Moscato, where the most abundant phenolic compound was quercetin 3-O-glucoside. In almost all samples, the most and least abundant anthocyanins were malvidin 3-O-glucoside and cyanidin 3-O-glucoside, respectively, with the exception of Uva di Troia where the least abundant anthocyanin was delphinidin 3-O-glucoside.     

Thiazole and oxazole alkaloids: isolation and synthesis

Thiazoles, oxazole and their corresponding reduced derivatives, thiazolines and oxazolines, are found in marine sources exhibiting significant biological activities. The isolation, synthetic, and biological studies of these natural products, covering literature from January 2007 to June 2010, are summarized.