Nanoparticles from culture media are internalized by in vitro-produced bovine embryos and its depletion affect expression of pluripotency genes

Extracellular vesicles are nanoparticles secreted by cell and have been proposed as suitable markers to identify competent embryos produced in vitro. Characterizing EVs secreted by individual embryos is challenging because culture medium itself contributes to the pool of nanoparticles that are co-isolated. To avoid this, culture medium must be depleted of nanoparticles that are present in natural protein source. The aim of this study was to evaluate if the culture medium subjected to nanoparticle depletion can support the proper in vitro development of bovine embryos. Zygotes were cultured in groups on depleted or control medium for 8 days. Nanoparticles from the medium were characterized by their morphology, size and expression of EVs surface markers. Isolated nanoparticles were labelled and added to depleted medium containing embryos at different developmental stages and evaluated after 24 hours at 2, 8-16 cells, morula and blastocyst stages. There were no statistical differences on blastocyst rate at day 7 and 8, total cell count neither blastocyst diameter between groups. However, morphological quality was better in blastocysts cultured in non-depleted medium and the expression of SOX2 was significantly lower whereas NANOG expression was significantly higher. Few nanoparticles from medium had a typical morphology of EVs but were positive to specific surface markers. Punctuated green fluorescence near the nuclei of embryonic cells was observed in embryos from all developmental stages. In summary, nanoparticles from culture medium are internalized by in vitro cultured bovine embryos and their depletion affects the capacity of medium to support the proper embryo development.     

Private and public determinants of child nutrition in Nicaragua and Western Honduras

We present a multivariate regression model of nutritional indicators, including interactions between education levels and overall community development, as well as estimates of community fixed effects, for two data sets: the first one is from a 2001 nationwide household survey in Nicaragua while the second set was collected in the Western regions of Honduras in 2002, as part of an evaluation process for a family entitlement program. Maternal stature, age difference with an older sibling, household size and income are seen as the main determinants of anthropometric development. Within the more homogeneous communities of Western Honduras, woman's education is also related to the child's nutritional status. The importance of individual community variables is much lower and the inclusion of community fixed effects does not alter the other parameters. However, in the Honduran sample, overall community development (assessed through the community fixed effects) has a small but significant and synergistic effect on the impact of child and household variables. The characteristics of this study and the complex design of entitlement programs prevent an adequate evaluation of those interventions within the poverty reduction strategies. The improvement of intra-community targeting seems to be a key orientation for redesign. An improved socio-economic situation, sound population and family policies, and an appropriate preventive public health care still are safe investments towards improvement of child health and nutrition.     

Impacts of introduced grasses on breeding season habitat use by northern bobwhite in the South Texas plains

Introduced grasses may affect diversity of native fauna and flora adversely, and disrupt ecosystem processes. Many rangelands in South Texas have been seeded to or have been colonized by buffelgrass (Pennisetum ciliare) and Lehmann lovegrass (Eragrostis lehmanniana), perennial bunchgrasses native to Africa. The objective of this research was to quantify impacts that these 2 species of introduced grasses may have on northern bobwhite (Colinus virginianus) habitat use on South Texas rangelands during the breeding period (Apr–Aug). We evaluated the effects of buffelgrass and Lehmann lovegrass on northern bobwhite nest habitat (n = 35 nests) and general habitat use sites (n = 86 radiomarked quail) with logistic regression and habitat selection functions based on simple saddlepoint approximations. Buffelgrass was used as a nesting substrate at 11% of nests; however, vegetation height and visual obstruction between 1 cm and 30 cm were the best predictors of nest site use. Areas of introduced grass coverage ≥15–20% were avoided by northern bobwhites at general habitat use organism-centered points, but not at nest site use points. Introduced grass coverage and forb coverage were the best predictors of general habitat use, and bobwhites avoided areas with ≥18% introduced grass cover. These results suggest that avoidance of areas with extensive introduced grass cover may indicate a reduction in usable habitat space for northern bobwhite in the western South Texas plains. Maintaining native grass stands while implementing localized control of introduced grasses could be used as a strategy to promote habitat for northern bobwhites. © 2011 The Wildlife Society.     

Lipidomic Analysis Reveals Altered Fatty Acid Metabolism in the Liver of the Symptomatic Niemann–Pick,Type C1 Mouse Model

Niemann–Pick disease, type C1 (NPC1) is a fatal, autosomal recessive, neurodegenerative disorder caused by mutations in the NPC1 gene. As a result of the genetic defect, there is accumulation of unesterified cholesterol and sphingolipids in the late endosomal/lysosomal system causing both visceral and neurological defects. These manifest clinically as hepatosplenomegaly, liver dysfunction, and neurodegeneration. While significant progress has been made to better understand NPC1, the downstream effects of cholesterol storage and the major mechanisms that drive these pathologies remains less understood. In this study, it is sought to investigate free fatty acid levels in Npc1^?/? mice with focus on the polyunsaturated ω‐3 and ω‐6 fatty acids. Since fatty acids are the main constituents of numerous lipids species, a discovery based lipidomic study of liver tissue in Npc1^?/? mice is also performed. To this end, alterations in fatty acid synthesis, including the ω‐3 and 6 fatty acids, are reported. Further, alterations in enzymes that regulate the synthesis of ω‐3 and 6 fatty acids are reported. Analysis of the liver lipidome reveals alterations in both storage and membrane lipids including ceramides, fatty acids, phosphatidylcholamines, phosphatidylglycerols, phosphatidylethanolamines, sphingomyelins, and triacylglycerols in Npc1^?/? mice at a late stage of disease.