289 research outputs found
Comparing the effects of dynamic computer visualization on undergraduate students’ understanding of osmosis with randomized posttest-only control group design
Multipotent Capacity of Immortalized Human Bronchial Epithelial Cells
While the adult murine lung utilizes multiple compartmentally restricted progenitor cells during homeostasis and repair, much less is known about the progenitor cells from the human lung. Translating the murine stem cell model to humans is hindered by anatomical differences between species. Here we show that human bronchial epithelial cells (HBECs) display characteristics of multipotent stem cells of the lung. These HBECs express markers indicative of several epithelial types of the adult lung when experimentally tested in cell culture. When cultured in three different three-dimensional (3D) systems, subtle changes in the microenvironment result in unique responses including the ability of HBECs to differentiate into multiple central and peripheral lung cell types. These new findings indicate that the adult human lung contains a multipotent progenitor cell whose differentiation potential is primarily dictated by the microenvironment. The HBEC system is not only important in understanding mechanisms for specific cell lineage differentiation, but also for examining changes that correlate with human lung diseases including lung cancer
Conservation and divergence of known apicomplexan transcriptional regulons
<p>Abstract</p> <p>Background</p> <p>The apicomplexans are a diverse phylum of parasites causing an assortment of diseases including malaria in a wide variety of animals and lymphoproliferation in cattle. Little is known about how these varied parasites regulate their transcriptional regulons. Even less is known about how regulon systems, consisting of transcription factors and target genes together with their associated biological process, evolve in these diverse parasites.</p> <p>Results</p> <p>In order to obtain insights into the differences in transcriptional regulation between these parasites we compared the orthology profiles of putative malaria transcription factors across species and examined the enrichment patterns of four binding sites across eleven apicomplexans.</p> <p>About three-fifths of the factors are broadly conserved in several phylogenetic orders of sequenced apicomplexans. This observation suggests the existence of regulons whose regulation is conserved across this ancient phylum. Transcription factors not broadly conserved across the phylum are possibly involved in regulon systems that have diverged between species. Examining binding site enrichment patterns in light of transcription factor conservation patterns suggests a second mode via which regulon systems may diverge - rewiring of existing transcription factors and their associated binding sites in specific ways. Integrating binding sites with transcription factor conservation patterns also facilitated prediction of putative regulators for one of the binding sites.</p> <p>Conclusions</p> <p>Even though transcription factors are underrepresented in apicomplexans, the distribution of these factors and their associated regulons reflect common and family-specific transcriptional regulatory processes.</p
PKC Theta Ablation Improves Healing in a Mouse Model of Muscular Dystrophy
Inflammation is a key pathological characteristic of dystrophic muscle lesion formation, limiting muscle regeneration and resulting in fibrotic and fatty tissue replacement of muscle, which exacerbates the wasting process in dystrophic muscles. Limiting immune response is thus one of the therapeutic options to improve healing, as well as to improve the efficacy of gene- or cell-mediated strategies to restore dystrophin expression. Protein kinase C θ (PKCθ) is a member of the PKCs family highly expressed in both immune cells and skeletal muscle; given its crucial role in adaptive, but also innate, immunity, it is being proposed as a valuable pharmacological target for immune disorders. In our study we asked whether targeting PKCθ could represent a valuable approach to efficiently prevent inflammatory response and disease progression in a mouse model of muscular dystrophy. We generated the bi-genetic mouse model mdx/θ−/−, where PKCθ expression is lacking in mdx mice, the mouse model of Duchenne muscular dystrophy. We found that muscle wasting in mdx/θ−/− mice was greatly prevented, while muscle regeneration, maintenance and performance was significantly improved, as compared to mdx mice. This phenotype was associated to reduction in inflammatory infiltrate, pro-inflammatory gene expression and pro-fibrotic markers activity, as compared to mdx mice. Moreover, BM transplantation experiments demonstrated that the phenotype observed was primarily dependent on lack of PKCθ expression in hematopoietic cells
'The mum has to live with the decision much more than the dad'; a qualitative study of men's perceptions of their influence on breastfeeding decision-making
© 2018 The Author(s). Background: Although breastfeeding is widely acknowledged as the normal method of infant feeding, there are large variations in rates of initiation and duration. Several factors are linked to the likelihood of breastfeeding initiation, including the influence and opinion of the child's father. There is limited research into men's perception of their influence, or if they feel it appropriate to be involved in deciding how to feed their children. The aim of this study was to investigate, using a qualitative methodology, fathers' perceptions of their influence on the decision to feed their child breastmilk or formula. Methods: Six men were recruited through Children's Centres in Bristol, United Kingdom, and a phenomenological research methodology implemented using semi-structured interviews. Specific objectives were: to understand participants' views on breastfeeding; understand if and how these views were discussed with their partner; to determine if participants believed involvement in the feeding decision is appropriate; to understand how they felt about the decision made; and to see if their views changed after the birth of their child. Results: Multiple themes emerged during analysis, including deferring of responsibility to the mother; breastfeeding as normal practice; change in attitude; involvement in parenting; and, advantages for the father. The men in the study accepted breastfeeding as normal behaviour, probably because of their upbringing in households where breastfeeding was practiced. There was consensus that women had more say in deciding to breastfeed, which was explained as a consequence of their greater involvement. It could also be interpreted as an unwillingness to interfere in an area perceived as 'owned' by women. Participants acknowledged that breastfeeding was more difficult than they had perceived. Conclusions: The key themes emerging from the interviews are suggestive of an impact on breastfeeding interventions that use the father as an intermediary. If they do not feel that they are 'permitted' to comment on their partner's breastfeeding, then simply increasing knowledge of breastfeeding benefits in these men is likely to have minimal impact
Short-term fatty acid intervention elicits differential gene expression responses in adipose tissue from lean and overweight men
The goal of this study was to investigate the effect of a short-term nutritional intervention on gene expression in adipose tissue from lean and overweight subjects. Gene expression profiles were measured after consumption of an intervention spread (increased levels of polyunsaturated fatty acids, conjugated linoleic acid and medium chain triglycerides) and a control spread (40 g of fat daily) for 9 days. Adipose tissue gene expression profiles of lean and overweight subjects were distinctly different, mainly with respect to defense response and metabolism. The intervention resulted in lower expression of genes related to energy metabolism in lean subjects, whereas expression of inflammatory genes was down-regulated and expression of lipid metabolism genes was up-regulated in the majority of overweight subjects. Individual responses in overweight subjects were variable and these correlated better to waist–hip ratio and fat percentage than BMI
Validação do índice de comprometimento cutaneomucoso do pênfigo vulgar para a avaliação clínica de pacientes com pênfigo vulgar
Cross species comparison of C/EBPα and PPARγ profiles in mouse and human adipocytes reveals interdependent retention of binding sites
<p>Abstract</p> <p>Background</p> <p>The transcription factors peroxisome proliferator activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα) are key transcriptional regulators of adipocyte differentiation and function. We and others have previously shown that binding sites of these two transcription factors show a high degree of overlap and are associated with the majority of genes upregulated during differentiation of murine 3T3-L1 adipocytes.</p> <p>Results</p> <p>Here we have mapped all binding sites of C/EBPα and PPARγ in human SGBS adipocytes and compared these with the genome-wide profiles from mouse adipocytes to systematically investigate what biological features correlate with retention of sites in orthologous regions between mouse and human. Despite a limited interspecies retention of binding sites, several biological features make sites more likely to be retained. First, co-binding of PPARγ and C/EBPα in mouse is the most powerful predictor of retention of the corresponding binding sites in human. Second, vicinity to genes highly upregulated during adipogenesis significantly increases retention. Third, the presence of C/EBPα consensus sites correlate with retention of both factors, indicating that C/EBPα facilitates recruitment of PPARγ. Fourth, retention correlates with overall sequence conservation within the binding regions independent of C/EBPα and PPARγ sequence patterns, indicating that other transcription factors work cooperatively with these two key transcription factors.</p> <p>Conclusions</p> <p>This study provides a comprehensive and systematic analysis of what biological features impact on retention of binding sites between human and mouse. Specifically, we show that the binding of C/EBPα and PPARγ in adipocytes have evolved in a highly interdependent manner, indicating a significant cooperativity between these two transcription factors.</p
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