Ontogenesis of the rumen: A comparative analysis of the Merino sheep and Iberian red deer

The aim of this study is to describe differences in the ontogenesis of the rumen in the sheep (domestic ruminant) and deer (wild ruminant). A total of 50 embryos and fetuses of Merino sheep and 50 of Iberian deer were used, from the first stages of prenatal life until birth. For the study, the animals were divided into five experimental groups according to the most relevant histological characteristics. The appearance of the rumen from the primitive gastric tube was earlier in the sheep (22% gestation, 33 days) than in the deer (25% gestation, 66 days). In both cases it displayed a primitive epithelium of a stratified, cylindrical, non‐ciliary type. At around 28% gestation in the sheep (42 days) and 26% (67 days) in the deer, the rumen was configured of three clearly‐differentiated layers: internal or mucosal, middle or muscular and external or serosal. In both species the stratification of the epithelial layer was accompanied by modifications in its structure with the appearance of the ruminal pillars and papillae. The pillars appeared before the papillae and the appearance of both structures was always earlier in the deer (pillars: 70 days, 27% gestation; papillae: 97 days, 36% gestation) than in the sheep (pillars: 42 days, 28% gestation; papillae: 57 days, 38% gestation). The outlines of the ruminal papillae appeared as evaginations of the basal zone toward the ruminal lumen, dragging in their formation the basal membrane, the lamina propria and the submucosa. The tegumentary mucosa of the rumen was without secretion capability in the first embryonic phases. From 67 days (26% gestation) the neutral mucopolysaccharides appeared in the deer and at 46 days (30% gestation) in the sheep. In both cases they continued to decrease until birth, this diminution being more pronounced in the deer. Finally, the presence of neuroendocrine and glial cells was detected in the deer at earlier stages than in the sheep.     

Mouse barley awn (Hordeum murinum) migration induced cystolithiasis in 2 male dogs

Two male dogs were presented with cystic uroliths composed of magnesium ammonium phosphate (struvite). Each had an atypical nidus, a mouse barley awn (Hordeum murinum). To our knowledge, this is the first report of grass awns located in the bladder lumen of dogs. The composition of uroliths and the pathophysiology of grass awn migration to the urinary bladder are discussed.     

Antiproliferative Properties of Scandium Exopolysaccharide Complexes on Several Cancer Cell Lines

Antimetastatic properties on both murine and human osteosarcoma cell lines (POS-1 and KHOS) have been evidenced using exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium. These derivatives had no significant effect on the cell cycle neither a pro-apoptotic effect on osteosarcoma cells. Based on this observation, these EPSs could be employed as new drug delivery systems for therapeutic uses. A theranostic approach, i.e., combination of a predictive biomarker with a therapeutic agent, has been developed notably by combining with true pair of theranostic radionuclides, such as scandium ⁴⁷Sc/⁴⁴Sc. However, it is crucial to ensure that, once complexation is done, the biological properties of the vector remain intact, allowing the molecular tropism of the ligand to recognize its molecular target. It is important to assess if the biological properties of EPS evidenced on osteosarcoma cell lines remain when scandium is complexed to the polymers and can be extended to other cancer cell types. Scandium-EPS complexes were thus tested in vitro on human cell lines: MNNG/HOS osteosarcoma, A375 melanoma, A549 lung adenocarcinoma, U251 glioma, MDA231 breast cancer, and Caco2 colon cancer cells. An xCELLigence Real Cell Time Analysis (RTCA) technology assay was used to monitor for 160 h, the proliferation kinetics of the different cell lines. The tested complexes exhibited an anti-proliferative effect, this effect was more effective compared to EPS alone. This increase of the antiproliferative properties was explained by a change in conformation of EPS complexes due to their polyelectrolyte nature that was induced by complexation. Alterations of both growth factor-receptor signaling, and transmembrane protein interactions could be the principal cause of the antiproliferative effect. These results are very promising and reveal that EPS can be coupled to scandium for improving its biological effects and also suggesting that no major structural modification occurs on the ligand.     

Cytoprotective effect of hydroxytyrosyl alkyl ether derivatives after oral administration to rats in a model of glucose-oxygen deprivation in brain slices

This study was designed to determine whether the oral administration of hydroxytyrosol (HT) alkyl ether derivatives has a neuroprotective effect in rats. The animals were treated for 7 days with HT or ethyl, butyl, hexyl, octyl, and dodecyl HT ether. A method of in vitro hypoxia-reoxygenation in brain slices was used. Hexyl, octyl, and dodecyl HT derivatives reduced brain cell death (LDH efflux). Lipid peroxidation and nitrite concentrations were inhibited most by hexyl, octyl, and dodecyl derivatives. Concentrations of 3-nitrotyrosine were reduced by HT butyl, hexyl, octyl, and dodecyl ether derivatives. Interleukin-1β was significantly reduced in brain slices from rats treated with all HT ether derivatives. LDH efflux showed a linear correlation with brain concentrations of lipid peroxides, nitrites plus nitrates, and interleukin 1β. The reduction in oxidative and nitrosative stress and decreased production of pro-inflammatory interleukins may be the basis for the observed neuroprotective effects.     

Molecular and cytogenetic characterization of a collection of bahiagrass (Paspalum notatum Flügge) native to Uruguay

Paspalum notatum is a subtropical grass present throughout America, and one of the main constituents of the natural grasslands in Uruguay. An apomictic autotetraploid (2n?=?4x?=?40) is the most frequent cytotype. The occurrence of sexual diploids (2n?=?2x?=?20) has also been reported as well as the occasional presence of apomictic triploids and pentaploids in Argentina. In this study, ISSR (inter simple sequence repeats) molecular markers were used to analyze the genetic variability of 210 P. notatum individuals from a collection from Uruguay. Cytometric analyses and chromosome counts were used to assess the ploidy level of the individuals. All plants from Uruguay analyzed were tetraploid. Intra- and inter-population variability was found both in genomic DNA content and at the genotypic level. Several multilocus genotypes were shared among individuals within populations and among populations over moderate geographical ranges, at the same time, very dissimilar genotypes were found within the same population. Part of the genetic variance among populations can be explained by a broader scale geographic structure which is partly coincident with the traditionally recognized grassland management regions. In spite of the apparently high degree of genetic admixture within populations, groups of related genotypes seem to follow a broader geographical structure in the area under study. These results suggest that an efficient collection strategy for this apomictically reproducing species should include carefully planned intra- and inter-population sampling. A broader scale regional sampling strategy should also be considered although further studies will be required to define genetic structure at this level.     

Pool of resistance mechanisms to glyphosate in Digitaria insularis

Digitaria insularis biotypes resistant to glyphosate have been detected in Brazil. Studies were carried out in controlled conditions to determine the role of absorption, translocation, metabolism, and gene mutation as mechanisms of glyphosate resistance in D. insularis. The susceptible biotype absorbed at least 12% more (14)C-glyphosate up to 48 h after treatment (HAT) than resistant biotypes. High differential (14)C-glyphosate translocation was observed at 12 HAT, so that >70% of the absorbed herbicide remained in the treated leaf in resistant biotypes, whereas 42% remained in the susceptible biotype at 96 HAT. Glyphosate was degraded to aminomethylphosphonic acid (AMPA), glyoxylate, and sarcosine by >90% in resistant biotypes, whereas a small amount of herbicide (up to 11%) was degraded by the susceptible biotype up to 168 HAT. Two amino acid changes were found at positions 182 and 310 in EPSPS, consisting of a proline to threonine and a tyrosine to cysteine substitution, respectively, in resistant biotypes. Therefore, absorption, translocation, metabolism, and gene mutation play an important role in the D. insularis glyphosate resistance.     

Effect of the spatial resolution on landscape control of soil fertility in a semiarid area

Purpose  

Most dryland ecosystems show high landscape heterogeneity that can influence soil fertility, although the underlying processes are still poorly understood. Furthermore, our understanding of the same could be affected by the scale dependency of the landscape representation. Here, we study the relationships between soil and landscape attributes at different spatial resolutions in a semiarid area, to better understand which landscape processes control soil fertility and whether such control is affected by the resolution of landscape representation.     

Development of a real-time SYBR Green PCR assay for the rapid detection of Dermatophilus congolensis

Methods such as real time (RT)-PCR have not been developed for the rapid detection and diagnosis of Dermatophilus (D.) congolensis infection. In the present study, a D. congolensis-specific SYBR Green RT-PCR assay was evaluated. The detection limit of the RT-PCR assay was 1 pg of DNA per PCR reaction. No cross-reaction with nucleic acids extracted from Pseudomonas aeruginosa, Mycobacterium tuberculosis, Staphylococcus aureus, or Austwickia chelonae was observed. Finally, the RT-PCR assay was used to evaluate clinical samples collected from naturally infected animals with D. congolensis. The results showed that this assay is a fast and reliable method for diagnosing dermatophilosis.