Lactic acid bacterial colonization and human rotavirus infection influence distribution and frequencies of monocytes/macrophages and dendritic cells in neonatal gnotobiotic pigs

Despite accumulating knowledge of porcine macrophages and dendritic cells (DCs) from in vitro studies, information regarding monocytes/macrophages and DCs in lymphoid tissues of enteric pathogen-infected neonatal animals in vivo is limited. In this study we evaluated the influence of commensal bacterial [two strains of lactic acid bacteria (LAB), Lactobacillus acidophilus and L. reuteri] colonization and rotavirus infection on distribution and frequencies of monocytes/macrophages and conventional DCs (cDCs) in ileum, spleen and blood. Gnotobiotic pigs were inoculated with LAB and virulent Wa strain human rotavirus (HRV) (LAB+HRV+), HRV only (LAB-HRV+), LAB only (LAB+HRV-) or mock (LAB-HRV-). The cDCs were characterized as SWC3(+)CD11R1(+), whereas monocytes/macrophages were identified as SWC3(+)CD11R1(-) by flow cytometry in the gnotobiotic pigs at 10 days of age. Infection with HRV alone activated/recruited significantly more monocytes/macrophages to the intestine than LAB colonization and 56% versus 28% of these cells expressed CD14. Colonization with LAB alone also significantly increased the frequencies of monocytes/macrophages and cDCs and the CD14 expression on monocytes/macrophages in ileum and spleen compared to the controls. LAB colonization plus HRV infection significantly reduced macrophage and cDC frequencies in spleen compared to LAB colonization or HRV infection alone, suggesting that LAB colonization down-regulated HRV- infection-induced monocyte/macrophage activation/recruitment at the systemic lymphoid tissue. These results illustrated the distribution of porcine monocytes/macrophages and cDCs and the frequencies of CD14 expression on these cells in intestinal and systemic lymphoid tissues in the early stage of immune responses to intestinal colonization by LAB versus infection by an enteric pathogen HRV and will facilitate further in vivo studies on functional characterization of these immune cells in neonates.     

Insights on gene expression response of a characterized resistant genotype of Solanum commersonii Dun. against Ralstonia solanacearum

Solanum commersonii is a wild species related to the cultivated potato. Some S. commersonii genotypes have been proven to be resistant to the pathogenic bacteria Ralstonia solanacearum, which causes damage in potato and other economically important crops. Here an expression analysis of the response of a resistant S. commersonii genotype against R. solanacearum was performed using microarrays. The aims of this work were to elucidate the molecular processes involved in the interaction, establish the timing of the response, and contribute to identify genes related to the resistance. The response to the treatment was already initiated at 6 h post-inoculation (hpi) and was established at 24 hpi; during this period, a high number of genes was differentially expressed and several candidate genes for the resistance of S. commersonii to R. solanacearum were identified. At an early stage, the photosynthetic process was highly repressed and several genes encoding proteins related to reactive oxygen species (ROS) production were differentially expressed. The induction of ERF and ACC-oxidase genes related to the ethylene pathway and PR1 related to the salicylic acid pathway suggested the induction of both pathways, and back up the previously reported hemibiotrophic nature of the pathogen. Five genes related to plant defence and observed to be differentially expressed at the first two time points were validated by real time PCR. This work gives a glimpse to the molecular processes involved in S. commersonii resistance and identifies the species as a valuable genetic source for potato breeding against bacterial wilt.     

Anatomical and Morphometric Variations in the Arterial System of the Domestic Cat

We document the anatomical architecture and frequency of occurrence of variations in the branching pattern of the brachiocephalic artery and the origin of the internal iliac arteries in the domestic cat, a widely used model organism in both anatomical training and research. Based on the study of 56 preserved specimens, we observed three distinct arrangements in the branching pattern of the brachiocephalic artery. The most common pattern (52% of the examined specimens) was that in which the brachiocephalic artery was divided into two branches, the left common carotid artery and a common branch for the right subclavian artery and the right common carotid artery. The frequency of occurrence of each variation type was independent of the gender and body size. The internal iliac arteries originated caudal to the point at which the external iliac arteries branched off from the abdominal aorta. However, the portion of the abdominal aorta between the external and internal iliac arteries varied greatly in length and was not significantly correlated with its width, nor with body size or gender. This study is the first to report and quantify the occurrence of such variations in North American cats. Given the anatomical similarity between the cat and other felids, the results of this study can be applied to other species, including endangered species.     

Implications of iron solubilization on soil phosphorus release in seasonally flooded forests of the lower Orinoco River, Venezuela

The microbial reduction of Fe oxides is thought to contribute with the release of P in sedimentary environments. However, secondary reactions of the bioproduced Fe(II) with P in solution, can lead to a decrease in the soluble P concentration. In this study, we examined how the reduction of Fe(III) affects the soluble P concentration, when the soils of a seasonally flooded forest gradient are subjected to anaerobic conditions. Soil samples were collected during the dry season from two zones subjected to different flooding intensity: MAX and MIN zones that were inundated 8 and 2 months per year, respectively. When anaerobic conditions were applied to soils from both zones, a clear stimulatory effect on the Fe(III) reduction was observed. However, bioproduced Fe(II) underwent secondary chemical reactions, masking the extend of Fe(III) reduction of these soils. Iron was reduced mainly during the first 15 days of the anaerobic incubation and it was stimulated by a pulse of labile carbon. Iron dissolution did not lead to an increase of the soluble P content. However, in both zones P was high and positively correlated with Fe(II), implying that soil P mobilization was linked to Fe dissolution. In the MIN zone, soluble P concentration decreased, probably as a consequence of the secondary reactions of solubilized P with other non-redox sensitive soils elements. Fe solubilization also had an effect on the activity of acid phosphatase and consequently in the solubilization of P from the organic pool. In conclusion, the P cycle in these soils is strongly coupled to C and Fe cycles.     

Optimization of the enzymatic deamidation of soy protein by protein-glutaminase and its effect on the functional properties of the protein

The effects of enzymatic deamidation by protein-glutaminase (PG) on the functional properties of soy protein isolate (SPI) were studied. Conditions for the deamidation were evaluated by means of response surface methodology (RSM). Optimal conditions based on achieving a high degree of deamidation (DD) with a concurrently low degree of hydrolysis (DH) were 44 °C, enzyme:substrate ratio (E/S) of 40 U/g protein and pH 7.0. Under optimal conditions, both DD and DH increased over time. SDS-PAGE results indicated that lower molecular mass subunits were produced with increasing DD. Far-UV circular dichroism spectra revealed that the α-helix structure decreased with higher DD, while the β-sheet structure increased until 15 min of deamidation (32.9% DD), but then decreased at higher DD. The solubility of deamidated SPI was enhanced under both acidic and neutral conditions. SPI with higher DD showed better emulsifying properties and greater foaming capacity than SPI, while foaming stability was decreased. It is possible to modify and potentially improve the functional properties of SPI by enzymatic deamidation using PG.     

Increasing and stabilizing β-sheet structure of maize zein causes improvement in its rheological properties

Wheat gluten proteins are considered to have the unique ability to form viscoelastic matrices that are essential for breadmaking. This study shows that maize seed storage protein (zein), if properly treated, can be made to function similarly to gluten at the protein secondary structure level with concomitant improved viscoelasticity. Here, we propose the concept of a small amount of coprotein (high molecular weight glutenin or casein) acting to stabilize a build-up of β-sheet structure in a zein-based dough, thus creating a viscoelastic matrix that is retained over time. This discovery is relevant to the need for gluten replacement viscoelastic proteins for wheat intolerant individuals and as well opens possibilities of creating wheatlike cereal varieties that could more cheaply substitute for wheat imports in developing countries.     

Kinetics and binding capacity of six soils for structurally defined hydrolyzable and condensed tannins and related phenols

Purpose  

We investigated tannin–soil interactions by assessing the kinetics of sorption and sorption capacities, and their relationship to the chemical properties of six polyphenolic compounds and the textures of six soils. We developed a new extraction procedure for recovering tannins from soil samples by successive extraction with solvents of decreasing polarity.     

Degradation of the herbicides clomazone, paraquat, and glyphosate by thermally activated peroxydisulfate

Activated sodium peroxydisulfate has the potential to in situ destruct many organic contaminants because of the generation of the stronger oxidant sulfate radical. From photochemical activation of peroxydisulfate in flash-photolysis experiments, the bimolecular rate constants for the reaction of sulfate radical with glyphosate (1.6 × 10(8) M(-1) s(-1)) and paraquat (1.2 × 10(9) M(-1) s(-1)) at 25 °C were obtained. Thermal activation of peroxydisulfate was shown to degrade the herbicides clomazone, paraquat, and glyphosate. Although the herbicide degradation was observed to take place in less than 1 h, the mineralization of the organic carbon required longer reaction times, because of the formation of stable organic intermediates. For similar initial total organic carbon (TOC) values, TOC profiles were similar for experiments with different substrates (the herbicides, humic acids, and a mixture of glyphosate and humic acids), which indicates that the mineralization of all of the samples is limited by the production of SO(4)(?)?(-) radicals. A linear correlation between the initial amount of SO(4)(?)?(-) needed per mole of C and the average oxidation state was found.