The action of excessive,inorganic silicon (Si) on the mineral metabolism of calcium (Ca) and magnesium (Mg)

The influence of silicon treatment on the levels of calcium and magnesium in blood serum and tissues was studied in rats. The concentrations of both elements were estimated in samples of sera and tissues of rats receiving per os a soluble, inorganic silicon compound—sodium metasilicate nonahydrate (Na₂SiO₃·9H₂O (REACHIM, USSR)), dissolved in the animals' drinking water. A decrease of magnesium concentration in serum was observed with accompanying elevation of registered calcemia. Moreover, a reduction of tissue calcium levels was found with a simultaneous increase of magnesium tissue pool. The results provide evidence for silicon involvement in mineral metabolism. It could result in a modification of pathological processes concerning bone tissue.     

Morphological assessment of the Octopus vulgaris species complex evaluated in light of molecular‐based phylogenetic inferences

Cryptic species are common in the ocean, particularly among marine invertebrates such as octopuses. Delineating cryptic species is particularly problematic in octopus taxonomy where the plasticity recorded among taxonomic characters often results in low resolution at the species level. This study investigated the morphological relationships among seven phylogenetic clades (identified using cytochrome c oxidase subunit I) of the broadly distributed Octopus vulgaris species complex and close relatives. Morphological analyses in this study were successful in delimiting O. sinensis, Brazilian O. vulgaris and O. vulgaris sensu stricto, which was congruent with the molecular findings of this study. Analyses based on male morphology were successful in distinguishing 14 of 15 total pairwise comparisons and proved to be a more reliable indicator of species‐level relationships in comparison with female morphology. The majority of characters with the greatest discriminatory power were male sexual traits. Significant morphological differences were also recorded among sampling localities of conspecifics, with phenotype showing correlation with local environmental data. The findings of this study support the hypothesis that multiple O. vulgaris‐like species are currently being incorrectly treated under a single species name, O. vulgaris. Octopuses being exported globally under the name O. vulgaris are of extremely high fisheries market value and profile. Our findings have potentially significant implications for the naming and conservation of commercially harvested members of this species complex throughout their ranges.     

Regeneration of a Gentiana pneumonanthe population in an oligotrophic wet meadow

Abstract. The aim of this study was to evaluate the critical phases of the life cycle of Gentiana pneumonanthe, the marsh gentian, a threatened species of the Bohemian flora. The effect of various conditions on germination and seedling establishment and the possible effect of competition on the performance of the species were tested. Seeds were sown in plots which were subjected to four treatments in a randomized complete blocks experiment: unmanaged meadow, mown meadow, burned meadow, and meadow with cut sod. The significantly highest recruitment was found in plots with cut sod, the lowest in the unmanaged control plots. Seedling survival also differed among the treatments. In the following year surviving individuals were only found in plots with cut sod. The influence of neighbouring vegetation on target gentian individuals was evaluated by removing the surrounding vegetation and comparing the performance of these individuals with controls. The initial height of each individual was measured and used as a covariable. No significant effect of neighbouring vegetation on performance was detected. Thus, the establishment phase appears to be critical for population persistence and is also more influenced by the management regime than other stages of the life cycle.     

Rebamipide Delivered by Brushite Cement Enhances Osteoblast and Macrophage Proliferation

Many of the bioactive agents capable of stimulating osseous regeneration, such as bone morphogenetic protein-2 (BMP-2) or prostaglandin E2 (PGE2), are limited by rapid degradation, a short bioactive half-life at the target site in vivo, or are prohibitively expensive to obtain in large quantities. Rebamipide, an amino acid modified hydroxylquinoline, can alter the expression of key mediators of bone anabolism, cyclo-oxygenase 2 (COX-2), BMP-2 and vascular endothelial growth factor (VEGF), in diverse cell types such as mucosal and endothelial cells or chondrocytes. The present study investigates whether Rebamipide enhances proliferation and differentiation of osteoblasts when delivered from brushite cement. The reactive oxygen species (ROS) quenching ability of Rebampide was tested in macrophages as a measure of bioactivity following drug release incubation times, up to 14 days. Rebamipide release from brushite occurrs via non-fickian diffusion, with a rapid linear release of 9.70% ±0.37% of drug per day for the first 5 days, and an average of 0.5%-1% per day thereafter for 30 days. Rebamipide slows the initial and final cement setting time by up to 3 and 1 minute, respectively, but does not significantly reduce the mechanical strength below 4% (weight percentage). Pre-osteoblast proliferation increases by 24% upon exposure to 0.4uM Rebamipide, and by up to 73% when Rebamipide is delivered via brushite cement. Low doses of Rebamipide do not adversely affect peak alkaline phosphatase activity in differentiating pre-osteoblasts. Rebamipide weakly stimulates proliferation in macrophages at low concentrations (118 ±7.4% at 1uM), and quenches ROS by 40-60%. This is the first investigation of Rebamipide in osteoblasts.     

Four kilograms of information: ramdom thoughts on Histocompatibility Testing 1987

B. Dupont (ed.): Immunobiology of HLA, Vol. I, Histocompatibility Testing 1987; Vol. II, Immunogenetics and Histocompatibility, Springer, New York, 1989.     

Don't judge a cell by its cover: heterogeneity within early lymphoid progenitors

B‐cell differentiation is one of the most recognized examples of the progressive lineage commitment that is distinctive for stem cell systems. However, the characteristics of the stage just before a cell becomes restricted to the B‐cell lineage are less understood. Using single‐cell RNA sequencing technology, Rolink and colleagues are able to define the cellular heterogeneity at this step and challenge our understanding of developmental trajectories in early B‐lymphoid development (Alberti‐Servera et al, 2017 ).