Effect of cell therapy with allogeneic osteoblasts on bone repair of rat calvaria defects

Background aims

Regenerative medicine strategies based on cell therapy are considered a promising approach to repair bone defects. The aims of this study were to evaluate the effect of subculturing on the osteogenic potential of osteoblasts derived from newborn rat calvaria and the effect of these osteoblasts on bone repair of rat calvaria defects.

Rapidly diminishing mangrove forests in Myanmar (Burma): a review

IPCC predictions indicate an increase in temperatures by 1.5–7°C in some Amazonian regions during the twenty-first century. These changes could disrupt the present distribution patterns of organisms, including wetland plant species. In this work, we determined in microcosms the effects of scenarios combining elevated temperature and atmospheric CO₂ concentration on the germination and initial growth of the arborescent Amazonian aquatic macrophyte Montrichardia arborescens. Seeds were germinated, and seedlings produced were monitored over a 5-month period in four microcosms: Control: ambient temperature and CO₂ level; Mild: Control + 1.5°C and + 200 ppm CO₂; intermediate: control + 2.5°C and + 400 ppm CO₂; Extreme: Control + 4.5°C and + 850 ppm of CO₂. Rapid light response curves and Fv/Fm values taken in seedlings showed a decrease in electron transportation rate with CO₂ and temperature elevation. Mild and Intermediate treatments stimulated biomass production; Extreme treatment and Control produced similar results. The severe climatic changes expected in the future may negatively influence carbon accumulation in M. arborescens. Since aquatic macrophytes in Amazonian wetlands and wetlands worldwide are key plant species, further studies are needed to predict their fate in a global change perspective.     

A new species of Drepanocnemis (Diptera,Muscidae) from Andes in Peru,with an updated phylogenetic analysis of species

Drepanocnemis Stein (Diptera, Muscidae) is a small genus of flies that occur in high altitudes in the Colombian Andes, Ecuador, Peru and Bolivia. Herein we describe Drepanocnemis aurifronssp. nov. from Cuzco, Peru, which is found from high (2904 m) to lower altitudes (707 m). An updated phylogeny, key to species and map of species’ distributions are provided, together with images and illustrations of the male and the female terminalia.     

A farm-scale investigation of the organic matter composition and soil chemistry of Andisols as influenced by land use and management

Andisols are characterised by having abundant reactive Al in the form of short-range ordered (SRO) Al constituents and organo-Al complexes, which facilitates the accumulation of soil organic matter (OM). However, recent studies of New Zealand pastoral systems have reported loss of carbon (C) from Andisols when under intense management. This study compares the organic and inorganic chemistry of Andisols on two adjacent pasture sites under different pastoral management regimes (Paddock 2 being more intensively managed than Paddock 1), as well as under a nearby pine stand (Forest). Mean soil pH-H₂O in Forest (5.3) was significantly lower (P?<?0.05) than that in Paddock 1 (5.7), which itself was significantly lower (P?<?0.05) than in Paddock 2 (6.1). Soil C concentrations were significantly higher (P?<?0.05) in the soils under pasture than under pine (63.8 g C/kg), and C in Paddock 1 (98.1 g C/kg) was significantly higher (P?<?0.05) than in Paddock 2 (84.1 g C/kg). The ratio of Al in organo-Al complexes (as estimated with sodium pyrophosphate) to the sum of Al in both SRO and organo-Al complexes (Al_p/Al_o) was significantly smaller (P?<?0.05) as the alkalinity of the soils increased (0.38, 0.23, 0.16 for Forest, Paddock 1 and Paddock 2, respectively). At the molecular level, soils under Forest had a larger relative contribution of degraded products of plant polysaccharides than those under pasture, while these had a larger contribution of fresh (e.g. cellulose and cutan/suberan aliphatic structures) and N-rich OM (e.g., microbial fingerprints, denoting a high microbial activity). Dissolved organic C content in the rhizosphere of pasture species was similar between paddocks, but Paddock 2 had a significantly (P?<?0.05) greater contribution of organic acids of MW?<?500 Da and higher pH (6.8 vs. 6.2). The results (1) confirm the common enrichment in organic C of New Zealand top soils under pasture compared to those under pine, and (2) reveal that the changes in the soil chemistry associated with pasture management may weaken the ability of these soils to preserve OM.     

Mutations in the carboxyl-terminal hydrophobic sequence of human cytomegalovirus glycoprotein B alter transport and protein chaperone binding.

Human cytomegalovirus glycoprotein B (gB) plays a role in the fusion of the virion envelope with the host cell membrane and in syncytium formation in infected cells. Hydrophobic sequences at the carboxyl terminus, amino acids (aa) 714 to 771, anchor gB in the lipid bilayer, but the unusual length of this domain suggests that it may serve another role in gB structure. To explore the function(s) of this region, we deleted aa 717 to 747 (gB deltaI mutation), aa 751 to 771 (gB deltaII mutation), and aa 717 to 772 (gB deltaI-II mutation) and constructed a substitution mutation, Lys-748 to Val (Lys748Val)-Asn749Ala-Pro750Ile (gB KNPm). Mutated forms of gB were expressed in U373 glioblastoma cells and subjected to analysis by flow cytometry, confocal microscopy, and immunoprecipitation. Mutations gB deltaI-II and gB deltaII alone caused secretion of gB into the medium, confirming that aa 751 to 771 function as a membrane anchor. In contrast, mutations gB deltaI and gB KNPm blocked cell surface expression and arrested gB transport in the endoplasmic reticulum (ER). Detailed examination of gB deltaI and gB KNPm with a panel of monoclonal antibodies showed that the mutated forms were indistinguishable from wild-type gB in conformation and formed oligomers; however, they remained sensitive to endoglycosidase H and did not undergo endoproteolytic cleavage. Analysis of protein complexes formed by gB and molecular chaperones in the ER showed that calnexin and calreticulin, lectin-like chaperones, bound equal amounts of uncleaved wild-type gB, gB deltaI, and gB KNPm, but the glucose-regulated proteins 78 (BiP) and 94 formed stable complexes only with the mutated forms, causing their retention in the ER. Our studies show that aa 714 to 750 are key residues in the architecture of gB molecules and that the ER chaperones, which facilitate gB folding and monitor the quality of glycoproteins, detect subtle changes in folding intermediates that are conferred by mutations in this region.