442 research outputs found
Strain-dependent host transcriptional responses to toxoplasma infection are largely conserved in mammalian and avian hosts
Toxoplasma gondii has a remarkable ability to infect an enormous variety of mammalian and avian species. Given this, it is surprising that three strains (Types I/II/III) account for the majority of isolates from Europe/North America. The selective pressures that have driven the emergence of these particular strains, however, remain enigmatic. We hypothesized that strain selection might be partially driven by adaptation of strains for mammalian versus avian hosts. To test this, we examine in vitro, strain-dependent host responses in fibroblasts of a representative avian host, the chicken (Gallus gallus). Using gene expression profiling of infected chicken embryonic fibroblasts and pathway analysis to assess host response, we show here that chicken cells respond with distinct transcriptional profiles upon infection with Type II versus III strains that are reminiscent of profiles observed in mammalian cells. To identify the parasite drivers of these differences, chicken fibroblasts were infected with individual F1 progeny of a Type II x III cross and host gene expression was assessed for each by microarray. QTL mapping of transcriptional differences suggested, and deletion strains confirmed, that, as in mammalian cells, the polymorphic rhoptry kinase ROP16 is the major driver of strain-specific responses. We originally hypothesized that comparing avian versus mammalian host response might reveal an inversion in parasite strain-dependent phenotypes; specifically, for polymorphic effectors like ROP16, we hypothesized that the allele with most activity in mammalian cells might be less active in avian cells. Instead, we found that activity of ROP16 alleles appears to be conserved across host species; moreover, additional parasite loci that were previously mapped for strain-specific effects on mammalian response showed similar strain-specific effects in chicken cells. These results indicate that if different hosts select for different parasite genotypes, the selection operates downstream of the signaling occurring during the beginning of the host's immune response. © 2011 Ong et al
Educating Cancer Prevention Researchers in Emerging Biobehavioral Models: Lessons Learned
To increase the adoption of transdisciplinary research methods among future cancer prevention investigators, faculty members from The University of Texas MD Anderson Cancer Center developed a graduate-level course in biobehavioral methods in cancer prevention research. Two instructors paired by topic and area of expertise offered an hour-long lecture-based seminar every week for 15 weeks during the spring semester of 2010. Students and presenters both evaluated the overall course content and delivery method, as well as each session. A total of 11 students and 22 presenters participated in the course. In each class session, one presenter was from a behavioral science background,and the other was from a biological sciences background. Both presenters and students expressed overall satisfaction with the content and format of the course. The presentation of topics from a transdisciplinary perspective and interaction with presenters from both biological and behavioral sciences are valuable and can help junior researchers prepare to meet the emerging challenges in cancer prevention research
Molecular signatures of maturing dendritic cells: implications for testing the quality of dendritic cell therapies
<p>Abstract</p> <p>Background</p> <p>Dendritic cells (DCs) are often produced by granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) stimulation of monocytes. To improve the effectiveness of DC adoptive immune cancer therapy, many different agents have been used to mature DCs. We analyzed the kinetics of DC maturation by lipopolysaccharide (LPS) and interferon-γ (IFN-γ) induction in order to characterize the usefulness of mature DCs (mDCs) for immune therapy and to identify biomarkers for assessing the quality of mDCs.</p> <p>Methods</p> <p>Peripheral blood mononuclear cells were collected from 6 healthy subjects by apheresis, monocytes were isolated by elutriation, and immature DCs (iDCs) were produced by 3 days of culture with GM-CSF and IL-4. The iDCs were sampled after 4, 8 and 24 hours in culture with LPS and IFN-γ and were then assessed by flow cytometry, ELISA, and global gene and microRNA (miRNA) expression analysis.</p> <p>Results</p> <p>After 24 hours of LPS and IFN-γ stimulation, DC surface expression of CD80, CD83, CD86, and HLA Class II antigens were up-regulated. Th1 attractant genes such as CXCL9, CXCL10, CXCL11 and CCL5 were up-regulated during maturation but not Treg attractants such as CCL22 and CXCL12. The expression of classical mDC biomarker genes CD83, CCR7, CCL5, CCL8, SOD2, MT2A, OASL, GBP1 and HES4 were up-regulated throughout maturation while MTIB, MTIE, MTIG, MTIH, GADD45A and LAMP3 were only up-regulated late in maturation. The expression of miR-155 was up-regulated 8-fold in mDCs.</p> <p>Conclusion</p> <p>DCs, matured with LPS and IFN-γ, were characterized by increased levels of Th1 attractants as opposed to Treg attractants and may be particularly effective for adoptive immune cancer therapy.</p
Instrumentos de avaliação do aleitamento materno e seu uso na prática clínica
RESUMO Objetivos Identificar instrumentos de avaliação da amamentação e sua aplicação na prática clínica, validação e adaptação transcultural. Método Revisão integrativa, realizada em seis bases de dados e em uma biblioteca eletrônica, entre agosto/2014-dezembro/2015, sem limitação temporal. Resultados Foram identificados 19 instrumentos de avaliação do AM. Destes, 12 foram validados e cinco foram adaptados transculturalmente. Quanto à aplicação, destacam-se seu uso para a avaliação do risco de desmame (BAPT) e a percepção/comportamento da mulher em amamentar (BSES-SF e IIFAS). Conclusão A identificação dos instrumentos disponíveis e de suas indicações para a avaliação do AM pode auxiliar profissionais na escolha pelo instrumento a ser utilizado, qualificando a assistência materno-infantil
Dental Occlusion in a Split Amazon Indigenous Population: Genetics Prevails over Environment
Background: Studies examining human and nonhuman primates have supported the hypothesis that the recent increase in
the occurrence of misalignment of teeth and/or incorrect relation of dental arches, named dental malocclusion, is mainly
attributed to the availability of a more processed diet and the reduced need for powerful masticatory action. For the first
time on live human populations, genetic and tooth wear influences on occlusal variation were examined in a split
indigenous population. The Arara-Iriri people are descendants of a single couple expelled from a larger village. In the
resultant village, expansion occurred through the mating of close relatives, resulting in marked genetic cohesion with
substantial genetic differences.
Methodology/Principal Findings: Dental malocclusion, tooth wear and inbreeding coefficient were evaluated. The sample
examined was composed of 176 individuals from both villages. Prevalence Ratio and descriptive differences in the
outcomes frequency for each developmental stage of the dentition were considered. Statistical differences between the
villages were examined using the chi-square test or Fisher’s exact statistic. Tooth wear and the inbreeding coefficient (F)
between the villages was tested with Mann-Whitney statistics. All the statistics were performed using two-tailed distribution
at p#0.05. The coefficient inbreeding (F) confirmed the frequent incestuous unions among the Arara-Iriri indigenous group.
Despite the tooth wear similarities, we found a striking difference in occlusal patterns between the two Arara villages. In the
original village, dental malocclusion was present in about one third of the population; whilst in the resultant village, the
occurrence was almost doubled. Furthermore, the morphological characteristics of malocclusion were strongly different
between the groups.
Conclusions/Significance: Our findings downplay the widespread influence of tooth wear, a direct evidence of what an
individual ate in the past, on occlusal variation of living human populations. They also suggest that genetics plays the most
important role on dental malocclusion etiology
Environmental controls, oceanography and population dynamics of pathogens and harmful algal blooms: connecting sources to human exposure
© 2008 Author et al. This is an open access article distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Environmental Health 7 (2008): S5, doi:10.1186/1476-069X-7-S2-S5.Coupled physical-biological models are capable of linking the complex interactions between environmental factors and physical hydrodynamics to simulate the growth, toxicity and transport of infectious pathogens and harmful algal blooms (HABs). Such simulations can be used to assess and predict the impact of pathogens and HABs on human health. Given the widespread and increasing reliance of coastal communities on aquatic systems for drinking water, seafood and recreation, such predictions are critical for making informed resource management decisions. Here we identify three challenges to making this connection between pathogens/HABs and human health: predicting concentrations and toxicity; identifying the spatial and temporal scales of population and ecosystem interactions; and applying the understanding of population dynamics of pathogens/HABs to management strategies. We elaborate on the need to meet each of these challenges, describe how modeling approaches can be used and discuss strategies for moving forward in addressing these challenges.The authors acknowledge the financial support for the NSF/NIEHS and
NOAA Centers for Oceans and Human Healt
Evolutional and clinical implications of the epigenetic regulation of protein glycosylation
Protein N glycosylation is an ancient posttranslational modification that enriches protein structure and function. The addition of one or more complex oligosaccharides (glycans) to the backbones of the majority of eukaryotic proteins makes the glycoproteome several orders of magnitude more complex than the proteome itself. Contrary to polypeptides, which are defined by a sequence of nucleotides in the corresponding genes, glycan parts of glycoproteins are synthesized by the activity of hundreds of factors forming a complex dynamic network. These are defined by both the DNA sequence and the modes of regulating gene expression levels of all the genes involved in N glycosylation. Due to the absence of a direct genetic template, glycans are particularly versatile and apparently a large part of human variation derives from differences in protein glycosylation. However, composition of the individual glycome is temporally very constant, indicating the existence of stable regulatory mechanisms. Studies of epigenetic mechanisms involved in protein glycosylation are still scarce, but the results suggest that they might not only be important for the maintenance of a particular glycophenotype through cell division and potentially across generations but also for the introduction of changes during the adaptive evolution
Expression of a Constitutively Active Calcineurin Encoded by an Intron-Retaining mRNA in Follicular Keratinocytes
Hair growth is a highly regulated cyclical process. Immunosuppressive immunophilin ligands such as cyclosporin A (CsA) and FK506 are known as potent hair growth modulatory agents in rodents and humans that induce active hair growth and inhibit hair follicle regression. The immunosuppressive effectiveness of these drugs has been generally attributed to inhibition of T cell activation through well-characterized pathways. Specifically, CsA and FK506 bind to intracellular proteins, principally cyclophilin A and FKBP12, respectively, and thereby inhibit the phosphatase calcineurin (Cn). The calcineurin (Cn)/NFAT pathway has an important, but poorly understood, role in the regulation of hair follicle development. Here we show that a novel-splicing variant of calcineurin Aß CnAß-FK, which is encoded by an intron-retaining mRNA and is deficient in the autoinhibitory domain, is predominantly expressed in mature follicular keratinocytes but not in the proliferating keratinocytes of rodents. CnAß-FK was weakly sensitive to Ca2+ and dephosphorylated NFATc2 under low Ca2+ levels in keratinocytes. Inhibition of Cn/NFAT induced hair growth in nude mice. Cyclin G2 was identified as a novel target of the Cn/NFATc2 pathway and its expression in follicular keratinocytes was reduced by inhibition of Cn/NFAT. Overexpression of cyclin G2 arrested the cell cycle in follicular keratinocytes in vitro and the Cn inhibitor, cyclosporin A, inhibited nuclear localization of NFATc2, resulting in decreased cyclin G2 expression in follicular keratinocytes of rats in vivo. We therefore suggest that the calcineurin/NFAT pathway has a unique regulatory role in hair follicle development
Prevalence and associated factors of depressive and anxiety symptoms during pregnancy: A population based study in rural Bangladesh
<p>Abstract</p> <p>Background</p> <p>Few studies have examined the associated factors of antepartum depressive and anxiety symptoms (ADS and AAS) in low-income countries, yet the World Health Organization identifies depressive disorders as the second leading cause of global disease burden by 2020. There is a paucity of research on mental disorders and their predictors among pregnant women in Bangladesh. This study aims to estimate the prevalence of depressive and anxiety symptoms and explore the associated factors in a cross-section of rural Bangladeshi pregnant women.</p> <p>Methods</p> <p>The study used cross-sectional data originating from a rural community-based prospective cohort study of 720 randomly selected women in their third trimester of pregnancy from a district of Bangladesh. The validated Bangla version of the Edinburgh Postnatal Depression Scale was used to measure ADS, and a trait anxiety inventory to assess general anxiety symptoms. Background information was collected using a structured questionnaire at the respondents' homes.</p> <p>Results</p> <p>Prevalence of ADS was 18% and AAS 29%. Women's literacy (OR 0.59, 95% CI 0.37-0.95), poor partner relationship (OR 2.23, 95% CI 3.37-3.62), forced sex (OR 1.95, 95% CI 1.01-3.75), physical violence by spouse (OR 1.69, 95% CI 1.02-2.80), and previous depression (OR 4.62 95% CI 2.72-7.85) were found to be associated with ADS. The associated factors of AAS were illiteracy, poor household economy, lack of practical support, physical partner violence, violence during pregnancy, and interaction between poor household economy and poor partner relationship.</p> <p>Conclusion</p> <p>Depressive and anxiety symptoms are found to occur commonly during pregnancy in Bangladesh, drawing attention to a need to screen for depression and anxiety during antenatal care. Policies aimed at encouraging practical support during pregnancy, reducing gender-based violence, supporting women with poor partner relationships, and identifying previous depression may ameliorate the potentially harmful consequences of antepartum depression and anxiety for the women and their family, particularly children.</p
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