2,038 research outputs found
Senescent vs. non-senescent cells in the human annulus in vivo: Cell harvest with laser capture microdissection and gene expression studies with microarray analysis
<p>Abstract</p> <p>Background</p> <p>Senescent cells are well-recognized in the aging/degenerating human disc. Senescent cells are viable, cannot divide, remain metabolically active and accumulate within the disc over time. Molecular analysis of senescent cells in tissue offers a special challenge since there are no cell surface markers for senescence which would let one use fluorescence-activated cell sorting as a method for separating out senescent cells.</p> <p>Methods</p> <p>We employed a novel laser capture microdissection (LCM) design to selectively harvest senescent and non-senescent annulus cells in paraffin-embedded tissue, and compared their gene expression with microarray analysis. LCM was used to separately harvest senescent and non-senescent cells from 11 human annulus specimens.</p> <p>Results</p> <p>Microarray analysis revealed significant differences in expression levels in senescent cells vs non-senescent cells: 292 genes were upregulated, and 321 downregulated. Genes with established relationships to senescence were found to be significantly upregulated in senescent cells vs. non-senescent cells: p38 (MPAK14), RB-Associated KRAB zinc finger, Discoidin, CUB and LCCL domain, growth arrest and DNA-damage inducible beta, p28ING5, sphingosine-1-phosphate receptor 2 and somatostatin receptor 3; cyclin-dependent kinase 8 showed significant downregulation in senescent cells. Nitric oxidase synthase 1, and heat shock 70 kDa protein 6, both of which were significantly down-regulated in senescent cells, also showed significant changes. Additional genes related to cytokines, cell proliferation, and other processes were also identified.</p> <p>Conclusions</p> <p>Our LCM-microarray analyses identified a set of genes associated with senescence which were significantly upregulated in senescent vs non-senescent cells in the human annulus. These genes include p38 MAP kinase, discoidin, inhibitor of growth family member 5, and growth arrest and DNA-damage-inducible beta. Other genes, including genes associated with cell proliferation, extracellular matrix formation, cell signaling and other cell functions also showed significant modulation in senescent vs non-senescent cells. The aging/degenerating disc undergoes a well-recognized loss of cells; understanding senescent cells is important since their presence further reduces the disc's ability to generate new cells to replace those lost to necrosis or apoptosis.</p
Some distorted thoughts about ketamine as a psychedelic and a novel hypothesis based on NMDA receptor-mediated synaptic plasticity.
Ketamine, a channel blocking NMDA receptor antagonist, is used off-label for its psychedelic effects, which may arise from a combination of several inter-related actions. Firstly, reductions of the contribution of NMDA receptors to afferent information from external and internal sensory inputs may distort sensations and their processing in higher brain centres. Secondly, reductions of NMDA receptor-mediated excitation of GABAergic interneurons can result in glutamatergic overactivity. Thirdly, limbic cortical disinhibition may indirectly enhance dopaminergic and serotonergic activity. Fourthly, inhibition of NMDA receptor mediated synaptic plasticity, such as short-term potentiation (STP) and long-term potentiation (LTP), could lead to distorted memories. Here, for the first time, we compared quantitatively the effects of ketamine on STP and LTP. We report that ketamine inhibits STP in a double sigmoidal fashion with low (40âŻnM) and high (5.6âŻÎźM) IC50 values. In contrast, ketamine inhibits LTP in a single sigmoidal manner (IC50 valueâŻâźâŻ15âŻÎźM). A GluN2D-subunit preferring NMDA receptor antagonist, UBP145, has a similar pharmacological profile. We propose that the psychedelic effects of ketamine may involve the inhibition of STP and, potentially, associated forms of working memory. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'
Expression and localization of estrogen receptor-β in annulus cells of the human intervertebral disc and the mitogenic effect of 17-β-estradiol in vitro
BACKGROUND: Recent evidence suggests that estrogens exert effects in different tissues throughout the body, and that the estrogen receptor β (ERβ) may be important for the action of estrogen (17-β-estradiol) on the skeleton. The cellular localization of ERβ in the human intervertebral disc, however, has not yet been explored. METHODS: Human disc tissue and cultured human disc cells were used for immunocytochemical localization of ERβ. mRNA was isolated from cultured human disc cells, and RT-PCR amplification of ERβ was employed to document molecular expression of this receptor. Cultured human disc cells were tested to determine if 17-β-estradiol stimulated cell proliferation. RESULTS: In this report data are presented which provide evidence for ERβ gene expression in human intervertebral disc cells in vivo and in vitro. Culture of annulus cells in the presence of 10(-7) M 17-β-estradiol significantly increased cell proliferation. CONCLUSIONS: These data provide new insight into the biology of cells in the annulus of the intervertebral disc
Communicating soil carbon science to farmers: incorporating credibility, salience and legitimacy
A key narrative within climate change science is that conserving and improving soil carbon through agricultural practices can contribute to agricultural productivity and is a promising option for mitigating carbon loss through sequestration. This paper examines the potential disconnect between science and practice in the context of communicating information about soil carbon management. It focuses on the information producing process and on stakeholder (adviser, farmer representative, policy maker etc) assessment of the attributes credibility, salience and legitimacy. In doing this it draws on results from consultations with stakeholders in the SmartSOIL project which aimed to provide decision support guidelines about practices that optimise carbon mitigation and crop productivity. An iterative methodology, used to engage stakeholders in developing, testing and validating a range of decision support guidelines in six case study regions across Europe, is described. This process enhanced legitimacy and revealed the importance, and the different dimensions, of stakeholder views on credibility and salience. The results also highlight the complexities and contested nature of managing soil carbon. Some insights are gained into how to achieve more effective communication about soil carbon management, including the need to provide opportunities in projects and research programmes for dialogue to engender better understanding between science and practice
Social capital factors affecting uptake of sustainable soil management practices: a literature review
Soil quality is in decline in many parts of the world, in part due to the
intensification of agricultural practices. Whilst economic instruments and
regulations can help incentivise uptake of more sustainable soil
management practices, they rarely motivate long-term behavior change
when used alone. There has been increasing attention towards the complex
social factors that affect uptake of sustainable soil management practices.
To understand why some communities try these practices whilst others do
not, we undertook a narrative review to understand how social capital
influences adoption in developed nations. We found that the four
components of social capital â trust, norms, connectedness and power â
can all influence the decision of farmers to change their soil management.
Specifically, information flows more effectively across trusted, diverse
networks where social norms exist to encourage innovation. Uptake is more
limited in homogenous, close-knit farming communities that do not have
many links with non-farmers and where there is a strong social norm to
adhere to the status quo. Power can enhance or inhibit uptake depending
on its characteristics. Future research, policy and practice should consider
whether a lack of social capital could hinder uptake of new practices and, if
so, which aspects of social capital could be developed to increase adoption
of sustainable soil management practices. Enabling diverse, collaborative
groups (including farmers, advisers and government officials) to work
constructively together could help build social capital, where they can
co-define, -develop and -enact measures to sustainably manage soils
Management of agricultural soils for greenhouse gas mitigation: Learning from a case study in NE Spain
A portfolio of agricultural practices is now available that can contribute to reaching European mitigation targets. Among them, the management of agricultural soils has a large potential for reducing GHG emissions or sequestering carbon. Many of the practices are based on well tested agronomic and technical know-how, with proven benefits for farmers and the environment. A suite of practices has to be used since none of the practices can provide a unique solution. However, there are limitations in the process of policy development: (a) agricultural activities are based on biological processes and thus, these practices are location specific and climate, soils and crops determine their agronomic potential; (b) since agriculture sustains rural communities, the costs and potential for implementation have also to be regionally evaluated and (c) the aggregated regional potential of the combination of practices has to be defined in order to inform abatement targets. We believe that, when implementing mitigation practices, three questions are important: Are they cost-effective for farmers? Do they reduce GHG emissions? What policies favour their implementation? This study addressed these questions in three sequential steps. First, mapping the use of representative soil management practices in the European regions to provide a spatial context to upscale the local results. Second, using a Marginal Abatement Cost Curve (MACC) in a Mediterranean case study (NE Spain) for ranking soil management practices in terms of their cost-effectiveness. Finally, using a wedge approach of the practices as a complementary tool to link science to mitigation policy. A set of soil management practices was found to be financially attractive for Mediterranean farmers, which in turn could achieve significant abatements (e.g., 1.34 MtCO2e in the case study region). The quantitative analysis was completed by a discussion of potential farming and policy choices to shape realistic mitigation policy at European regional level
Feasibility cluster randomised controlled trial of a within-consultation intervention to reduce antibiotic prescribing for children presenting to primary care with acute respiratory tract infection and cough
Objective To investigate recruitment and retention, data collection methods and the acceptability of a âwithin-consultationâ complex intervention designed to reduce antibiotic prescribing.
Design Primary care feasibility cluster randomised controlled trial.
Setting 32 general practices in South West England recruiting children from October 2014 to April 2015.
Participants Children (aged 3 months to <12 years) with acute cough and respiratory tract infection (RTI).
Intervention A web-based clinician-focussed clinical rule to predict risk of future hospitalisation and a printed leaflet with individualised child health information for carers, safety-netting advice and a treatment decision record.
Controls Usual practice, with clinicians recording data on symptoms, signs and treatment decisions.
Results Of 542 children invited, 501 (92.4%) consented to participate, a month ahead of schedule. Antibiotic prescribing data were collected for all children, follow-up data for 495 (98.8%) and the National Health Service resource use data for 494 (98.6%). The overall antibiotic prescribing rates for childrenâs RTIs were 25% and 15.8% (p=0.018) in intervention and control groups, respectively. We found evidence of postrandomisation differential recruitment: the number of children recruited to the intervention arm was higher (292 vs 209); over half were recruited by prescribing nurses compared with less than a third in the control arm; children in the intervention arm were younger (median age 2 vs 3 years controls, p=0.03) and appeared to be more unwell than those in the control arm with higher respiratory rates (p<0.0001), wheeze prevalence (p=0.007) and global illness severity scores assessed by carers (p=0.045) and clinicians (p=0.01). Interviews with clinicians confirmed preferential recruitment of less unwell children to the trial, more so in the control arm.
Conclusion Differential recruitment may explain the paradoxical antibiotic prescribing rates. Future cluster level studies should consider designs which remove the need for individual consent postrandomisation and embed the intervention within electronic primary care records
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Use of biobehavioral interventions in children undergoing surgery and associated patient-reported outcomes
Background: Biobehavioral interventions including relaxation, distraction, and mindfulness meditation exercises have been shown to decrease perioperative stress, anxiety, and pain. Our aims were to 1) quantify pediatric surgical patient-reported pre-operative exposure to and post-operative use of biobehavioral interventions; 2) understand barriers and facilitators to incorporation of biobehavioral interventions into clinical practice; and 3) evaluate associated patient-reported outcomes. Methods: We conducted an embedded mixed-methods study with a quantitative focus. Data were collected as part of the 18-hospital ENhanced Recovery In CHildren Undergoing Surgery (ENRICH-US) clinical trial for children, ages 10â18 years, undergoing elective gastrointestinal surgery. Patients/caregivers were surveyed about preoperative exposure to and postoperative use of biobehavioral interventions. Four semi-structured group interviews with 20 pediatric surgery providers were conducted. Outcomes included pain-related functional disability, health-related quality of life (HRQoL), and perioperative nervousness. Results: 41 % (n = 67) of 164 enrolled patients/caregivers reported preoperative exposure to and 71 % (n = 117) reported postoperative use of a biobehavioral intervention(s). Barriers to incorporation of biobehavioral interventions included lack of standardized workflows, clinician knowledge, and resources. Potential facilitators included media and peer-counseling. After adjusting for individual and hospital characteristics, those who reported using a biobehavioral intervention(s) were 70 % less likely to report worsened postoperative nervousness (95 % CI 0.10â0.91; p = 0.03). Reported use of a biobehavioral intervention(s) was not found to be associated with pain-related functional disability or HRQoL. Conclusions: Use of a biobehavioral intervention(s) may stabilize postoperative nervousness of children undergoing surgery. There is a need for redesign of clinical workflows and clinician training to facilitate integration of biobehavioral interventions.</p
Asporin, a susceptibility gene in osteoarthritis, is expressed at higher levels in the more degenerate human intervertebral disc
Adipose Tissue Depots and Their CrossâSectional Associations With Circulating Biomarkers of Metabolic Regulation
Background: Visceral adipose tissue (VAT) and fatty liver differ in their associations with cardiovascular risk compared with subcutaneous adipose tissue (SAT). Several biomarkers have been linked to metabolic derangements and may contribute to the pathogenicity of fat depots. We examined the association between fat depots on multidetector computed tomography and metabolic regulatory biomarkers. Methods and Results: Participants from the Framingham Heart Study (n=1583, 47% women) underwent assessment of SAT, VAT, and liver attenuation. We measured circulating biomarkers secreted by adipose tissue or liver (adiponectin, leptin, leptin receptor, fatty acid binding protein 4, fetuinâA, and retinol binding protein 4). Using multivariable linear regression models, we examined relations of fat depots with biomarkers. Higher levels of fat depots were positively associated with leptin and fatty acid binding protein 4 but negatively associated with adiponectin (all P<0.001). Associations with leptin receptor, fetuinâA, and retinol binding protein 4 varied according to fat depot type or sex. When comparing the associations of SAT and VAT with biomarkers, VAT was the stronger correlate of adiponectin (β=â0.28 [women]; β=â0.30 [men]; both P<0.001), whereas SAT was the stronger correlate of leptin (β=0.62 [women]; β=0.49 [men]; both P<0.001; P<0.001 for comparing VAT versus SAT). Although fetuinâA and retinol binding protein 4 are secreted by the liver in addition to adipose tissue, associations of liver attenuation with these biomarkers was not stronger than that of SAT or VAT. Conclusions: SAT, VAT, and liver attenuation are associated with metabolic regulatory biomarkers with differences in the associations by fat depot type and sex. These findings support the possibility of biological differences between fat depots
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