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101.
Alejandro Córdova Rocío Hernández-Gil Cristian Alejandro Córdova-Jiménez Diogo José Cardilli Kellen de Sousa Oliveira José Félix Pérez-Gutiérrez 《Reproductive biology》2013,13(2):166-168
The effect of post-thaw incubation (0 vs. 5 h at 15 °C) and straw size (5 vs. 0.5 ml) on motility, acrosomal integrity and in vitro fertilizing (IVF) capacity of cryopreserved boar spermatozoa was studied. In samples assessed immediately after thawing, no differences were found between the two straw sizes. After 5 h post-thaw incubation, all parameters, except polyspermy, decreased and, spermatozoa packaged in 5 ml straws showed better functional and IVF parameters than these in 0.5 ml straws. 相似文献
102.
Alejandro E.J. Valenzuela Andrea Raya Rey Laura Fasola Ricardo A. Sáenz Samaniego Adrián Schiavini 《Mammalian Biology》2013,78(2):104-110
The American mink (Neovison vison) is a semi-aquatic, generalist carnivore released onto Tierra del Fuego (TDF) Island in the 1940s, subsequently spreading to adjacent islands in the archipelago with potential effects on native prey populations. Knowledge of this new predator's trophic ecology is essential to identify threats, plan control strategies and conserve native fauna. We studied seasonal mink diet in TDF in different habitats. We identified undigested remains from 493 scats collected between May 2005 and March 2009 along marine coasts and freshwater shores (rivers and lakes). Small mammals and fish were the main mink prey in TDF (over 65% of diet items). Seasonal variations were not detected, but diet did vary significantly between marine and freshwater habitats, where more terrestrial items were consumed. Among mammals, mink consumed more small native rodents than exotic species. Native fish consumption was also important with greater representation of species from the families Nototheniidae and Galaxiidae in marine and freshwater habitats respectively. Birds were the third item in importance, but did not constitute a particularly large part of the mink's diet on TDF. Overall, differences found in mink diet between habitats reflected their generalist/opportunistic feeding behaviour and did not differ greatly from observations in its native range or in other areas where it has been introduced. Our results establish the interactions between this novel predator and its prey and also illustrate the need to continue research on native prey populations to quantify mink impact on them and understand the ecological context of this biotic assemblage. 相似文献
103.
104.
Jun-Lin Guan Anna Katharina Simon Mark Prescott Javier A. Menendez Fei Liu Fen Wang Chenran Wang Ernst Wolvetang Alejandro Vazquez-Martin Jue Zhang 《Autophagy》2013,9(6):830-849
Autophagy is a highly conserved cellular process by which cytoplasmic components are sequestered in autophagosomes and delivered to lysosomes for degradation. As a major intracellular degradation and recycling pathway, autophagy is crucial for maintaining cellular homeostasis as well as remodeling during normal development, and dysfunctions in autophagy have been associated with a variety of pathologies including cancer, inflammatory bowel disease and neurodegenerative disease. Stem cells are unique in their ability to self-renew and differentiate into various cells in the body, which are important in development, tissue renewal and a range of disease processes. Therefore, it is predicted that autophagy would be crucial for the quality control mechanisms and maintenance of cellular homeostasis in various stem cells given their relatively long life in the organisms. In contrast to the extensive body of knowledge available for somatic cells, the role of autophagy in the maintenance and function of stem cells is only beginning to be revealed as a result of recent studies. Here we provide a comprehensive review of the current understanding of the mechanisms and regulation of autophagy in embryonic stem cells, several tissue stem cells (particularly hematopoietic stem cells), as well as a number of cancer stem cells. We discuss how recent studies of different knockout mice models have defined the roles of various autophagy genes and related pathways in the regulation of the maintenance, expansion and differentiation of various stem cells. We also highlight the many unanswered questions that will help to drive further research at the intersection of autophagy and stem cell biology in the near future. 相似文献
105.
We have elucidated a novel mechanism through which the autophagy-specific class III phosphatidylinositol 3-kinase (PtdIns3K) complex can be recruited to the PAS in mammalian cells, through the interaction between BECN1 and the vacuole membrane protein 1 (VMP1), an integral autophagosomal membrane protein. This interaction involves the binding between the C-terminal 20 amino acids of the VMP1 hydrophilic domain, which we have named the VMP1 autophagy-related domain (VMP1-AtgD), and the BH3 domain of BECN1. The association between these two proteins allows the formation of the autophagy-specific PtdIns3K complex, which activity favors the generation of phosphatidylinositol-3-phosphate (PtdIns3P) and the subsequent association of the autophagy-related (ATG) proteins, including ATG16L1, with the phagophore membranes. Therefore, VMP1 regulates the PtdIns3K activity on the phagophore membrane through its interaction with BECN1. Our data provide a novel model describing one of the key steps in phagophore assembly site (PAS) formation and autophagy regulation, and positions VMP1 as a new interactor of the autophagy-specific PtdIns3K complex in mammalian cells. 相似文献
106.
Jennifer A. Borcherding Haihan Chen Juan C. Caraballo Jonas Baltrusaitis Alejandro A. Pezzulo Joseph Zabner Vicki H. Grassian Alejandro P. Comellas 《PloS one》2013,8(2)
Air pollution is a risk factor for respiratory infections, and one of its main components is particulate matter (PM), which is comprised of a number of particles that contain iron, such as coal fly ash (CFA). Since free iron concentrations are extremely low in airway surface liquid (ASL), we hypothesize that CFA impairs antimicrobial peptides (AMP) function and can be a source of iron to bacteria. We tested this hypothesis in vivo by instilling mice with Pseudomonas aeruginosa (PA01) and CFA and determine the percentage of bacterial clearance. In addition, we tested bacterial clearance in cell culture by exposing primary human airway epithelial cells to PA01 and CFA and determining the AMP activity and bacterial growth in vitro. We report that CFA is a bioavailable source of iron for bacteria. We show that CFA interferes with bacterial clearance in vivo and in primary human airway epithelial cultures. Also, we demonstrate that CFA inhibits AMP activity in vitro, which we propose as a mechanism of our cell culture and in vivo results. Furthermore, PA01 uses CFA as an iron source with a direct correlation between CFA iron dissolution and bacterial growth. CFA concentrations used are very relevant to human daily exposures, thus posing a potential public health risk for susceptible subjects. Although CFA provides a source of bioavailable iron for bacteria, not all CFA particles have the same biological effects, and their propensity for iron dissolution is an important factor. CFA impairs lung innate immune mechanisms of bacterial clearance, specifically AMP activity. We expect that identifying the PM mechanisms of respiratory infections will translate into public health policies aimed at controlling, not only concentration of PM exposure, but physicochemical characteristics that will potentially cause respiratory infections in susceptible individuals and populations. 相似文献
107.
Ximena Moncada Claudia Payacán Francisco Arriaza Sergio Lobos Daniela Seelenfreund Andrea Seelenfreund 《PloS one》2013,8(2)
Background
Paper mulberry has been used for thousands of years in Asia and Oceania for making paper and bark-cloth, respectively. Museums around the world hold valuable collections of Polynesian bark-cloth. Genetic analysis of the plant fibers from which the textiles were made may answer a number of questions of interest related to provenance, authenticity or species used in the manufacture of these textiles. Recovery of nucleic acids from paper mulberry bark-cloth has not been reported before.Methodology
We describe a simple method for the extraction of PCR-amplifiable DNA from small samples of contemporary Polynesian bark-cloth (tapa) using two types of nuclear markers. We report the amplification of about 300 bp sequences of the ITS1 region and of a microsatellite marker.Conclusions
Sufficient DNA was retrieved from all bark-cloth samples to permit successful PCR amplification. This method shows a means of obtaining useful genetic information from modern bark-cloth samples and opens perspectives for the analyses of small fragments derived from ethnographic materials. 相似文献108.
Nir Eynon Emiliya S. Nasibulina Lauren K. Banting Pawel Cieszczyk Agnieszka Maciejewska-Karlowska Marek Sawczuk Elvira A. Bondareva Roza R. Shagimardanova Maytal Raz Yael Sharon Alun G. Williams Ildus I. Ahmetov Alejandro Lucia Ruth Birk 《PloS one》2013,8(4)
Objective
The FTO A/T polymorphism (rs9939609) is a strong candidate to influence obesity-related traits. Elite athletes from many different sporting disciplines are characterized by low body fat. Therefore, the aim of this study was to assess whether athletic status is associated with the FTO A/T polymorphism.Subjects and Methods
A large cohort of European Caucasians from Poland, Russia and Spain were tested to examine the association between FTO A/T polymorphism (rs9939609) and athletic status. A total of 551 athletes were divided by type of sport (endurance athletes, n = 266 vs. sprint/power athletes, n = 285) as well as by level of competition (elite-level vs. national-level). The control group consisted of 1,416 ethnically-matched, non-athletic participants, all Europeans. Multinomial logistic regression analyses were conducted to assess the association between FTO A/T genotypes and athletic status/competition level.Results
There were no significantly greater/lesser odds of harbouring any type of genotype when comparing across athletic status (endurance athletes, sprint/power athletes or control participants). These effects were observed after controlling for sex and nationality. Furthermore, no significantly greater/lesser odds ratios were observed for any of the genotypes in respect to the level of competition (elite-level vs. national-level).Conclusion
The FTO A/T polymorphism is not associated with elite athletic status in the largest group of elite athletes studied to date. Large collaborations and data sharing between researchers, as presented here, are strongly recommended to enhance the research in the field of exercise genomics. 相似文献109.
Koen Peeters Grietens Joan Muela Ribera Veronica Soto Alex Tenorio Sarah Hoibak Angel Rosas Aguirre Elizabeth Toomer Hugo Rodriguez Alejandro Llanos Cuentas Umberto D'Alessandro Dionicia Gamboa Annette Erhart 《PloS one》2013,8(1)
Background
While coverage of long-lasting insecticide-treated nets (LLIN) has steadily increased, a growing number of studies report gaps between net ownership and use. We conducted a mixed-methods social science study assessing the importance of net preference and use after Olyset® LLINs were distributed through a mass campaign in rural communities surrounding Iquitos, the capital city of the Amazonian region of Peru.Methods
The study was conducted in the catchment area of the Paujil and Cahuide Health Centres (San Juan district) between July 2007 and November 2008. During a first qualitative phase, participant observation and in-depth interviews collected information on key determinants for net preference and use. In a second quantitative phase, a survey among recently confirmed malaria patients evaluated the acceptability and use of both LLINs and traditional nets, and a case control study assessed the association between net preference/use and housing structure (open vs. closed houses).Results
A total of 10 communities were selected for the anthropological fieldwork and 228 households participated in the quantitative studies. In the study area, bed nets are considered part of the housing structure and are therefore required to fulfil specific architectural and social functions, such as providing privacy and shelter, which the newly distributed Olyset® LLINs ultimately did not. The LLINs'' failure to meet these criteria could mainly be attributed to their large mesh size, transparency and perceived ineffectiveness to protect against mosquitoes and other insects, resulting in 63.3% of households not using any of the distributed LLINs. Notably, LLIN usage was significantly lower in houses with no interior or exterior walls (35.2%) than in those with walls (73.8%) (OR = 5.2, 95CI [2.2; 12.3], p<0.001).Conclusion
Net preference can interfere with optimal LLIN use. In order to improve the number of effective days of LLIN protection per dollar spent, appropriate quantitative and qualitative methods for collecting information on net preference should be developed before any LLIN procurement decision is made. 相似文献110.
Alvaro A. Sandoval-Montiel Martha Zentella-de-Pi?a José L. Ventura-Gallegos Susana Frías-González Ambar López-Macay Alejandro Zentella-Dehesa 《PloS one》2013,8(6)