Regulation of phospholipase D by P2X7 receptors in submandibular ductal cells

ATP (1 mM) increased the phospholipase D (PLD) activity of rat submandibular gland (RSMG) ductal cells in a concentration-dependent and calcium-sensitive manner. The response to ATP was reproduced by benzoylbenzoyl-ATP (Bz-ATP, 100 microM) and also partly by adenosine 5'-(gamma-thio)triphosphate (ATPgammaS, 1 mM). A similar stimulation was observed in control mice (P2X7R+/+ mice) but not in mice lacking the P2X7 receptors (P2X7R-/- mice). Oxidized ATP and Coomassie blue or the addition of magnesium or nickel to the incubation medium inhibited the response to ATP. The stimulation of PLD by purinergic agonist was inhibited by about 50% by calphostin C and chelerythrine, two protein kinase C (PKC) inhibitors. The stimulation of PLD by Bz-ATP and by o-tetradecanoylphorbol 13-acetate (TPA), a phorbol ester which activates PKC, were not additive.From these results we can conclude that the activation of P2X7 receptors in RSMG ductal cells is coupled to the activation of a PLD. This activation is partly mediated by protein kinase C.     

Methionine sulfoxide formation in proteins: NMR study

Summary ¹H-NMR spectra of bovine pancreatic trypsin inhibitor (BPTI) both native and oxidized by chloramine T, are reported. The spectrum of the oxidized form is characterized by the appearance of two singlets for methyl group shifted 0.60 and 0.46 ppm downfield with respect to the native form.     

Effects of Partial Replacement of Corn with Glycerin on Ruminal Fermentation in a Dual-Flow Continuous Culture System

The objective of this study was to evaluate the effects of partially replacing dry ground corn with glycerin on ruminal fermentation using a dual-flow continuous culture system. Six fermenters (1,223 ± 21 ml) were used in a replicated 3x3 Latin square arrangement with three periods of 10 d each, with 7 d for diet adaptation and 3 d for sample collections. All diets contained 75% concentrate and three dietary glycerin levels (0, 15, and 30% on dry matter basis), totaling six replicates per treatment. Fermenters were fed 72 g of dry matter/d equally divided in two meals/d, at 0800 and 2000 h. Solid and liquid dilution rates were adjusted daily to 5.5 and 11%/h, respectively. On d 8, 9, and 10, samples of 500 ml of solid and liquid digesta effluent were mixed, homogenized, and stored at -20°C. Subsamples of 10 ml were collected and preserved with 0.2 mL of a 50% H₂SO₄ solution for later determination of NH₃-N and volatile fatty acids. Microbial biomass was isolated from fermenters for chemical analysis at the end of each experimental period. Data were analyzed using the MIXED procedure in SAS with α = 0.05. Glycerin levels did not affect apparent digestibility of DM (P _Lin. = 0.13; P _Quad. = 0.40), OM (P _Lin. = 0.72; P _Quad. = 0.15), NDF (P _Lin. = 0.38; P _Quad. = 0.50) and ADF (P _Lin. = 0.91; P _Quad. = 0.18). Also, glycerin inclusion did not affect true digestibility of DM (P _Lin. = 0.35; P _Quad. = 0.48), and OM (P _Lin. = 0.08; P _Quad. = 0.19). Concentrations of propionate (P < 0.01) and total volatile fatty acids (P < 0.01) increased linearly and concentrations of acetate (P < 0.01), butyrate (P = 0.01), iso-valerate (P < 0.01), and total branched-chain volatile fatty acids, as well as the acetate: propionate ratio (P < 0.01) decreased with glycerin inclusion. Linear increases on NH₃-N concentration in digesta effluent (P < 0.01) and on NH₃-N flow (P < 0.01) were observed due to glycerin inclusion in the diets. Crude protein digestibility (P = 0.04) and microbial N flow (P = 0.04) were greater in the control treatment compared with the other treatments and responded quadratically with glycerin inclusion. Furthermore, the inclusion of glycerin linearly decreased (P = 0.02) non-ammonia N flow. Glycerin levels did not affect the flows of total N (P _Lin. = 0.79; P _Quad. = 0.35), and dietary N (P _Lin. = 0.99; P _Quad. = 0.07), as well as microbial efficiency (P _Lin. = 0.09; P _Quad. = 0.07). These results suggest that partially replacing dry ground corn with glycerin may change ruminal fermentation, by increasing total volatile fatty acids, and propionate concentration without affecting microbial efficiency, which may improve glucogenic potential of beef cattle diets.     

Apricot Melanoidins Prevent Oxidative Endothelial Cell Death by Counteracting Mitochondrial Oxidation and Membrane Depolarization

The cardiovascular benefits associated with diets rich in fruit and vegetables are thought to be due to phytochemicals contained in fresh plant material. However, whether processed plant foods provide the same benefits as unprocessed ones is an open question. Melanoidins from heat-processed apricots were isolated and their presence confirmed by colorimetric analysis and browning index. Oxidative injury of endothelial cells (ECs) is the key step for the onset and progression of cardiovascular diseases (CVD), therefore the potential protective effect of apricot melanoidins on hydrogen peroxide-induced oxidative mitochondrial damage and cell death was explored in human ECs. The redox state of cytoplasmic and mitochondrial compartments was detected by using the redox-sensitive, fluorescent protein (roGFP), while the mitochondrial membrane potential (MMP) was assessed with the fluorescent dye, JC-1. ECs exposure to hydrogen peroxide, dose-dependently induced mitochondrial and cytoplasmic oxidation. Additionally detected hydrogen peroxide-induced phenomena were MMP dissipation and ECs death. Pretreatment of ECs with apricot melanoidins, significantly counteracted and ultimately abolished hydrogen peroxide-induced intracellular oxidation, mitochondrial depolarization and cell death. In this regard, our current results clearly indicate that melanoidins derived from heat-processed apricots, protect human ECs against oxidative stress.     

Rosaceae conserved orthologous sequences marker polymorphism in sweet cherry germplasm and construction of a SNP-based map

The Rosaceae Conserved Orthologous Set (RosCOS) provides a gene-based genome-wide set of markers that have been used in comparative analyses of peach (Prunus persica), apple (Malus × domestica), and strawberry (Fragaria spp.). In order to extend the use of these RosCOS to sweet cherry (Prunus avium L.), we identified markers that are polymorphic in breeding germplasm. Ninety-five percent (595/627) of previously designed RosCOS primer pairs amplified a product in six sweet cherry cultivars predicted to represent the range of genetic diversity in breeding germplasm. A total of 45% (282/627) RosCOS were polymorphic among the six cultivars, and allele number ranged from 2 to 6, with a genome-wide mean of 2.35. A subset of 92 genome-wide single nucleotide polymorphisms (SNPs) corresponding to 76 RosCOS was analyzed in 36 founder accessions and progeny. The expected and observed heterozygosity suggested that 83% of the RosCOS were in Hardy–Weinberg equilibrium, implying that most RosCOS behave as neutral markers. Principal coordinate analysis (PCO) identified one wild accession and two Spanish landraces that clustered differently from the other accessions. The relatively high number of unique alleles found in the three differentially clustered selections suggested that their use as parents has potential to increase the genetic diversity in future US-bred cultivars. Of the 92 RosCOS SNPs, 81 SNPs that represented 68 genome-wide RosCOS segregated in four mapping populations. These RosCOS were mapped in four F₁ populations, thereby greatly improving the genetic linkage map of sweet cherry.     

A tale of two cyclists: a cross-cultural comparison between Taiwanese and Filipino perceptions on cycling infrastructure landscapes

How is cycling culture defined? Because the word “culture” brings with it deep complexities, there is a need to understand varying contexts in looking for suitable strategies toward the advancement of cycling culture. The stage for cycling culture is the landscape where cycling infrastructure can be properly provided. With development, an influential element would be economic capacity. The paper explores the influence of the economic development divide by comparing cyclist perception between developed and developing countries, namely Taiwan and the Philippines. An online survey between 122 Taiwanese and 111 Filipino cyclists was conducted to find out the landscape needs of people to consider cycling transport based on affordances in the landscape. The variables selected were based on landscape elements for cycling as a commuting activity. The data were processed through factor analysis to reveal latent landscape needs to profile cycling needs. Two factors were identified as ‘environmental’ and ‘civil facilities.’ The factor loadings were then compared based on the nationalities which revealed that the bike riding motivation were different with relating to the context of their respective environment and similar with the basic infrastructural demands.