371 research outputs found

    Systems biology approach to identify transcriptome reprogramming and candidate microRNA targets during the progression of polycystic kidney disease

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    Background: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by cyst formation throughout the kidney parenchyma. It is caused by mutations in either of two genes, PKD1PKD1 and PKD2PKD2. Mice that lack functional Pkd1(Pkd1/)Pkd1 (Pkd1^{-/-}), develop rapidly progressive cystic disease during embryogenesis, and serve as a model to study human ADPKD. Genome wide transcriptome reprogramming and the possible roles of micro-RNAs (miRNAs) that affect the initiation and progression of cyst formation in the Pkd1/Pkd1^{-/-} have yet to be studied. miRNAs are small, regulatory non-coding RNAs, implicated in a wide spectrum of biological processes. Their expression levels are altered in several diseases including kidney cancer, diabetic nephropathy and PKD. Results: We examined the molecular pathways that modulate renal cyst formation and growth in the Pkd1/Pkd1^{-/-} model by performing global gene-expression profiling in embryonic kidneys at days 14.5 and 17.5. Gene Ontology and gene set enrichment analysis were used to identify overrepresented signaling pathways in Pkd1/Pkd1^{-/-} kidneys. We found dysregulation of developmental, metabolic, and signaling pathways (e.g. Wnt, calcium, TGFβTGF-\beta and MAPK) in Pkd/Pkd^{-/-} kidneys. Using a comparative transcriptomics approach, we determined similarities and differences with human ADPKD: ~50% overlap at the pathway level among the mis-regulated pathways was observed. By using computational approaches (TargetScan, miRanda, microT and miRDB), we then predicted miRNAs that were suggested to target the differentially expressed mRNAs. Differential expressions of 9 candidate miRNAs, miRs-10a, -30a-5p, -96, -126-5p, -182, -200a, -204, -429 and -488, and 16 genes were confirmed by qPCR. In addition, 14 candidate miRNA:mRNA reciprocal interactions were predicted. Several of the highly regulated genes and pathways were predicted as targets of miRNAs. Conclusions: We have described global transcriptional reprogramming during the progression of PKD in the Pkd1/Pkd1^{-/-} model. We propose a model for the cascade of signaling events involved in cyst formation and growth. Our results suggest that several miRNAs may be involved in regulating signaling pathways in ADPKD. We further describe novel putative miRNA:mRNA signatures in ADPKD, which will provide additional insights into the pathogenesis of this common genetic disease in humans

    Automated Ecological Assessment of Physical Activity: Advancing Direct Observation.

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    Technological advances provide opportunities for automating direct observations of physical activity, which allow for continuous monitoring and feedback. This pilot study evaluated the initial validity of computer vision algorithms for ecological assessment of physical activity. The sample comprised 6630 seconds per camera (three cameras in total) of video capturing up to nine participants engaged in sitting, standing, walking, and jogging in an open outdoor space while wearing accelerometers. Computer vision algorithms were developed to assess the number and proportion of people in sedentary, light, moderate, and vigorous activity, and group-based metabolic equivalents of tasks (MET)-minutes. Means and standard deviations (SD) of bias/difference values, and intraclass correlation coefficients (ICC) assessed the criterion validity compared to accelerometry separately for each camera. The number and proportion of participants sedentary and in moderate-to-vigorous physical activity (MVPA) had small biases (within 20% of the criterion mean) and the ICCs were excellent (0.82-0.98). Total MET-minutes were slightly underestimated by 9.3-17.1% and the ICCs were good (0.68-0.79). The standard deviations of the bias estimates were moderate-to-large relative to the means. The computer vision algorithms appeared to have acceptable sample-level validity (i.e., across a sample of time intervals) and are promising for automated ecological assessment of activity in open outdoor settings, but further development and testing is needed before such tools can be used in a diverse range of settings

    Chlamydia Hijacks ARF GTPases To Coordinate Microtubule Posttranslational Modifications and Golgi Complex Positioning.

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    The intracellular bacterium Chlamydia trachomatis develops in a parasitic compartment called the inclusion. Posttranslationally modified microtubules encase the inclusion, controlling the positioning of Golgi complex fragments around the inclusion. The molecular mechanisms by which Chlamydia coopts the host cytoskeleton and the Golgi complex to sustain its infectious compartment are unknown. Here, using a genetically modified Chlamydia strain, we discovered that both posttranslationally modified microtubules and Golgi complex positioning around the inclusion are controlled by the chlamydial inclusion protein CT813/CTL0184/InaC and host ARF GTPases. CT813 recruits ARF1 and ARF4 to the inclusion membrane, where they induce posttranslationally modified microtubules. Similarly, both ARF isoforms are required for the repositioning of Golgi complex fragments around the inclusion. We demonstrate that CT813 directly recruits ARF GTPases on the inclusion membrane and plays a pivotal role in their activation. Together, these results reveal that Chlamydia uses CT813 to hijack ARF GTPases to couple posttranslationally modified microtubules and Golgi complex repositioning at the inclusion.IMPORTANCEChlamydia trachomatis is an important cause of morbidity and a significant economic burden in the world. However, how Chlamydia develops its intracellular compartment, the so-called inclusion, is poorly understood. Using genetically engineered Chlamydia mutants, we discovered that the effector protein CT813 recruits and activates host ADP-ribosylation factor 1 (ARF1) and ARF4 to regulate microtubules. In this context, CT813 acts as a molecular platform that induces the posttranslational modification of microtubules around the inclusion. These cages are then used to reposition the Golgi complex during infection and promote the development of the inclusion. This study provides the first evidence that ARF1 and ARF4 play critical roles in controlling posttranslationally modified microtubules around the inclusion and that Chlamydia trachomatis hijacks this novel function of ARF to reposition the Golgi complex

    Perceived neighborhood environmental attributes associated with walking and cycling for transport among adult residents of 17 cities in 12 countries: The IPEN study

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    Introduction: Prevalence of walking and cycling for transport is low and varies greatly across countries. Few studies have examined neighborhood perceptions related to walking and cycling for transport in different countries. Therefore, it is challenging to prioritize appropriate built-environment interventions. Objectives: The aim of this study was to examine the strength and shape of the relationship between adults’ neighborhood perceptions and walking and cycling for transport across diverse environments. Methods: As part of the International Physical activity and Environment Network (IPEN) adult project, self-reported data were taken from 13,745 adults (18–65 years) living in physically and socially diverse neighborhoods in 17 cities across 12 countries. Neighborhood perceptions were measured using the Neighborhood Environment Walkability Scale, and walking and cycling for transport were measured using the International Physical Activity Questionnaire–Long Form. Generalized additive mixed models were used to model walking or cycling for transport during the last seven days with neighborhood perceptions. Interactions by city were explored. Results: Walking-for-transport outcomes were significantly associated with perceived residential density, land use mix–access, street connectivity, aesthetics, and safety. Any cycling for transport was significantly related to perceived land use mix–access, street connectivity, infrastructure, aesthetics, safety, and perceived distance to destinations. Between-city differences existed for some attributes in relation to walking or cycling for transport. Conclusions: Many perceived environmental attributes supported both cycling and walking; however, highly walkable environments may not support cycling for transport. People appear to walk for transport despite safety concerns. These findings can guide the implementation of global health strategies

    Influence of providers and nurses on completion of non-targeted HIV screening in an urgent care setting

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    Introduction: Despite recommendations by the Centers for Disease Control (CDC) that all adults be offered non-targeted HIV screening in all care settings, screening in acute-care settings remains unacceptably low. We performed an observational study to evaluate an HIV screening pilot in an academic-community partnership health center urgent care clinic. Methods: We collected visit data via encounter forms and demographic and laboratory data from electronic medical records. A post-pilot survey of perceptions of HIV screening was administered to providers and nurses. Multivariable analysis was used to identify factors associated with completion of testing. Results: Visit provider and triage nurse were highly associated with both acceptance of screening and completion of testing, as were younger age, male gender, and race/ethnicity. 23.5% of patients completed tests, although 36.0% requested screening; time constraints as well as risk perceptions by both the provider and patient were cited as limiting completion of screening. Post-pilot surveys showed mixed support for ongoing HIV screening in this setting by providers and little support by nurses. Conclusions: Visit provider and triage nurse were strongly associated with acceptance of testing, which may reflect variable opinions of HIV screening in this setting by clinical staff. Among patients accepting screening, visit provider remained strongly associated with completion of testing. Despite longstanding recommendations for non-targeted HIV screening, further changes to improve the testing and results process, as well as provider education and buy-in, are needed to improve screening rates

    Assessing Awareness and Competence of Best Practices in Synchronous Online Instruction During the COVID-19 Pandemic for Clemson Cooperative Extension Professionals

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    Traditional delivery of Extension programming changed overnight in March 2020, when the COVID-19 outbreak forced switching traditional methods to virtual delivery. Extension professionals across South Carolina quickly adapted to online delivery. Concerns over instructor preparedness to use online tools, including functions to assure accessibility, did arise. Findings from this non-experimental, descriptive research study suggested Extension professionals used online tools (primarily Zoom). The majority were not comfortable using many of the features that would enhance instruction, including polling, file transfer, and live-streaming media platforms. Additionally, Microsoft Word and PowerPoint skills to assure accessibility for clientele were lacking

    Regulatory effects of interleukin‐11 during acute lung inflammatory injury

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    The role of interleukin‐11 (IL‐11) was evaluated in the IgG immune complex model of acute lung injury in rats. IL‐11 mRNA and protein were both up‐regulated during the course of this inflammatory response. Exogenously administered IL‐11 substantially reduced, in a dose‐dependent manner, the intrapulmonary accumulation of neutrophils and the lung vascular leak of albumin. These in vivo anti‐inflammatory effects of IL‐11 were associated with reduced NF‐κB activation in lung, reduced levels of tumor necrosis factor α (TNF‐α) in bronchoalveolar lavage (BAL) fluids, and diminished up‐regulation of lung vascular ICAM‐1. It is interesting that IL‐11 did not affect BAL fluid content of the CXC chemokines, macrophage inflammatory protein‐2 (MIP‐2) and cytokine‐inducible neutrophil chemoattractant (CINC); the presence of IL‐11 did not affect these chemokines. However, BAL content of C5a was reduced by IL‐11. These data indicate that IL‐11 is a regulatory cytokine in the lung and that, like other members of this family, its anti‐inflammatory properties appear to be linked to its suppression of NF‐κB activation, diminished production of TNF‐α, and reduced up‐regulation of lung vascular ICAM‐1. J. Leukoc. Biol. 66: 151–157; 1999.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141937/1/jlb0151.pd

    Perceived Neighborhood Environmental Attributes Associated with Walking and Cycling for Transport among Adult Residents of 17 Cities in 12 Countries: The IPEN Study

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    Introduction Prevalence of walking and cycling for transport is low and varies greatly across countries. Few studies have examined neighborhood perceptions related to walking and cycling for transport in different countries. Therefore, it is challenging to prioritize appropriate built-environment interventions. Objectives The aim of this study was to examine the strength and shape of the relationship between adults’ neighborhood perceptions and walking and cycling for transport across diverse environments. Methods As part of the International Physical activity and Environment Network (IPEN) adult project, self-reported data were taken from 13,745 adults (18–65 years) living in physically and socially diverse neighborhoods in 17 cities across 12 countries. Neighborhood perceptions were measured using the Neighborhood Environment Walkability Scale, and walking and cycling for transport were measured using the International Physical Activity Questionnaire–Long Form. Generalized additive mixed models were used to model walking or cycling for transport during the last seven days with neighborhood perceptions. Interactions by city were explored. Results Walking-for-transport outcomes were significantly associated with perceived residential density, land use mix–access, street connectivity, aesthetics, and safety. Any cycling for transport was significantly related to perceived land use mix–access, street connectivity, infrastructure, aesthetics, safety, and perceived distance to destinations. Between-city differences existed for some attributes in relation to walking or cycling for transport. Conclusions Many perceived environmental attributes supported both cycling and walking; however, highly walkable environments may not support cycling for transport. People appear to walk for transport despite safety concerns. These findings can guide the implementation of global health strategies
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