3,901 research outputs found
Apolipoprotein E delivery by peritoneal implantation of encapsulated recombinant cells improves the hyperlipidaemic profile in apoE-deficient mice
Plasma apolipoprotein E (apoE) is a 34-kDa polymorphic protein which has atheroprotective actions by clearing remnant lipoproteins and sequestering excess cellular cholesterol. Low or dysfunctional apoE is a risk factor for hyperlipidaemia and atherosclerosis, and for restenosis after angioplasty. Here, in short-term studies designed to establish proof-of-principle, we investigate whether encapsulated recombinant Chinese hamster ovary (CHO) cells can secrete wild-type apoE3 protein in vitro and then determine whether peritoneal implantation of the microcapsules into apoE-deficient (apoE(-/-)) mice reduces their hypercholesterolaemia.Recombinant CHO-E3 cells were encapsulated into either alginate poly-L-lysine or alginate polyethyleneimine/polybrene microspheres. After verifying stability and apoE3 secretion, the beads were then implanted into the peritoneal cavity of apoE(-/-) mice; levels of plasma apoE3, cholesterol and lipoproteins were monitored for up to 14 days post-implantation.Encapsulated CHO-E3 cells continued to secrete apoE3 protein throughout a 60-day study period in vitro, though levels declined after 14 days. This cell-derived apoE3 was biologically active. When conditioned medium from encapsulated CHO-E3 cells was incubated with cultured cells pre-labelled with [H-3]-cholesterol, efflux of cholesterol was two to four times greater than with normal medium (at 8 h, for example, 7.4+/-0.3% vs. 2.4+/-0.2% of cellular cholesterol; P<0.001). Moreover, when secreted apoE3 was injected intraperitoneally into apoE(-/-) mice, apoE3 was detected in plasma and the hyperlipidaemia improved. Similarly, when alginate polyethyleneimine/polybrene capsules were implanted into the peritoneum of apoE(-/-) mice, apoE3 was secreted into plasma and at 7 days total cholesterol was reduced, while atheroprotective high-density lipoprotein (HDL) increased. In a second study, apoE was detectable in plasma of five mice treated with alginate poly-L-lysine beads, 4 and 7 days post-implantation, though not at day 14. Furthermore, their hypercholesterolaemia was reduced, while HDL was clearly elevated in all mice at days 4 and 7 (from 18.4+/-6.2% of total lipoproteins to 31.1+/-6.8% at 7 days; P<0.001); however, these had rebounded by day 14, possibly due to the emergence of anti-apoE antibodies.We conclude that microencapsulated apoE-secreting cells have the potential to ameliorate the hyperlipidaemia of apoE deficiency, but that the technology must be improved to become a feasible therapeutic to treat atherosclerosis. (C) 2004 Elsevier B.V. All rights reserved
Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management
Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor) to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i) food quantity, (ii) food quality, and (iii) the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems
111In-labelled polymeric nanoparticles incorporating a ruthenium-based radiosensitizer for EGFR-targeted combination therapy in oesophageal cancer cells
Radiolabelled, drug-loaded nanoparticles may combine the theranostic properties of radionuclides, the controlled release of chemotherapy and cancer cell targeting. Here, we report the preparation of poly(lactic-co-glycolic acid) (PLGA) nanoparticles surface conjugated to DTPA-hEGF (DTPA = diethylenetriaminepentaacetic acid, hEGF = human epidermal growth factor) and encapsulating the ruthenium-based DNA replication inhibitor and radiosensitizer Ru(phen)2(tpphz)2+ (phen = 1,10-phenanthroline, tpphz = tetrapyridophenazine) Ru1. The functionalized PLGA surface incorporates the metal ion chelator DTPA for radiolabelling and the targeting ligand for EGF receptor (EGFR). Nanoparticles radiolabelled with 111In are taken up preferentially by EGFR-overexpressing oesophageal cancer cells, where they exhibit radiotoxicity through the generation of cellular DNA damage. Moreover, nanoparticle co-delivery of Ru1 alongside 111In results in decreased cell survival compared to single-agent formulations; an effect that occurs through DNA damage enhancement and an additive relationship between 111In and Ru1. Substantially decreased uptake and radiotoxicity of nanoparticles towards normal human fibroblasts and oesophageal cancer cells with normal EGFR levels is observed. This work demonstrates nanoparticle co-delivery of a therapeutic radionuclide plus a ruthenium-based radiosensitizer can achieve combinational and targeted therapeutic effects in cancer cells that overexpress EGFR
Removal of ecotoxicity of 17α-ethinylestradiol using TAML/peroxide water treatment
17α -ethinylestradiol (EE2), a synthetic oestrogen in oral contraceptives, is one of many pharmaceuticals found in inland waterways worldwide as a result of human consumption and excretion into wastewater treatment systems. At low parts per trillion (ppt), EE2 induces feminisation of male fish, diminishing reproductive success and causing fish population collapse. Intended water quality standards for EE2 set a much needed global precedent. Ozone and activated carbon provide effective wastewater treatments, but their energy intensities and capital/operating costs are formidable barriers to adoption. Here we describe the technical and environmental performance of a fast- developing contender for mitigation of EE2 contamination of wastewater based upon smallmolecule, full-functional peroxidase enzyme replicas called “TAML activators”. From neutral to basic pH, TAML activators with H2O2 efficiently degrade EE2 in pure lab water, municipal effluents and
EE2-spiked synthetic urine. TAML/H2O2 treatment curtails estrogenicity in vitro and substantially diminishes fish feminization in vivo. Our results provide a starting point for a future process in which tens of thousands of tonnes of wastewater could be treated per kilogram of catalyst. We suggest TAML/H2O2 is a worthy candidate for exploration as an environmentally compatible, versatile, method for removing EE2 and other pharmaceuticals from municipal wastewaters.Heinz Endowments, the Swiss National Science Foundation, the Steinbrenner Institute for a Steinbrenner
Doctoral Fellowship. NMR instrumentation at CMU was partially supported by NSF (CHE-0130903 and
CHE-1039870)
A new framework to assess relative ecosystem vulnerability to climate change
Climate change poses a growing risk to global biodiversity. To prioritize conservation efforts, identification of the species and ecosystems most at risk from further changes in climatic conditions is critically needed. Although frameworks are available to assess species vulnerability to climate change, we still lack an easily implementable, ecosystem‐level perspective to inform landscape management. Here, we introduce a novel, spatially explicit vulnerability framework able to generate assessments at the ecosystem scale and apply it to Mozambican forest mangroves, which are under growing pressures from climate change. Results show that most of these ecosystems are currently highly vulnerable to sea level rise, while mangroves in the Zambezia and Nampula districts are highly vulnerable to both sea level rise and tropical storms. Altogether, we believe the introduced assessment framework has clear potential to inform conservation planning and management at various spatial scales, and help achieve adaptive management in the face of climatic uncertainties
Recommendations for delivering oral health advice: a qualitative supplementary analysis of dental teams, parents’ and children’s experiences
Background:
Tooth decay has a significant impact on children, their families and wider society. The dental consultation provides an opportunity to prevent tooth decay by engaging in an effective oral health conversation with parents and children. However, there is limited literature which explores how these oral health conversations are delivered, received, and understood.
Aim:
To explore the common facilitators of delivering oral health advice from dental teams, parents' and children's experiences, to identify and inform practical recommendations for clinical practice.
Method:
The current paper used a qualitative supplementary analysis to reanalyse data of existing published studies by applying a different research question. Qualitative focus groups were undertaken following a semi-structured interview guide with 27 dental team members (dentists, dental nurses, practice managers and receptionists), 37 parents and 120 children (aged 7–10 years old) in the northern region of England. Thematic analysis informed the identification of themes and aggregation of findings.
Results:
Three overarching themes were developed: (1) An engaging and personalised dental visit for parents and children; (2) Dental teams, parents and children working collaboratively to improve oral health habits; and (3) Recommending appropriate oral health products. Many parents and children had little recollection of any preventive oral health conversations when visiting the dentist. Practical solutions were identified by different stakeholders to facilitate three-way, personalised, non-judgemental and supportive oral health conversations. Adopting these innovative approaches will help to enable parents and their children to adopt and maintain appropriate oral health behaviours.
Conclusion:
Understanding the context and triangulating the experiences of stakeholders involved in preventive oral health conversations for young children is an essential step in co-designing a complex oral health intervention. This study has provided recommendations for dental practices and wider paediatric health care services. Furthermore, the findings have informed the design of a complex oral health intervention called "Strong Teeth"
Excess ribosomal protein production unbalances translation in a model of Fragile X Syndrome
Dysregulated protein synthesis is a core pathogenic mechanism in Fragile X Syndrome (FX). The mGluR Theory of FX predicts that pathological synaptic changes arise from the excessive translation of mRNAs downstream of mGlu1/5 activation. Here, we use a combination of CA1 pyramidal neuron-specific TRAP-seq and proteomics to identify the overtranslating mRNAs supporting exaggerated mGlu1/5 -induced long-term synaptic depression (mGluR-LTD) in the FX mouse model (Fmr1−/y). Our results identify a significant increase in the translation of ribosomal proteins (RPs) upon mGlu1/5 stimulation that coincides with a reduced translation of long mRNAs encoding synaptic proteins. These changes are mimicked and occluded in Fmr1−/y neurons. Inhibiting RP translation significantly impairs mGluR-LTD and prevents the length-dependent shift in the translating population. Together, these results suggest that pathological changes in FX result from a length-dependent alteration in the translating population that is supported by excessive RP translation
Internet-Based Photoaging Within Australian Pharmacies to Promote Smoking Cessation: Randomized Controlled Trial
Background: Tobacco smoking leads to death or disability and a drain on national resources. The literature suggests that cigarette smoking continues to be a major modifiable risk factor for a variety of diseases and that smokers aged 18-30 years are relatively resistant to antismoking messages due to their widely held belief that they will not be lifelong smokers. Objective: To conduct a randomized controlled trial (RCT) of a computer-generated photoaging intervention to promote smoking cessation among young adult smokers within a community pharmacy setting. Methods: A trial was designed with 80% power based on the effect size observed in a published pilot study; 160 subjects were recruited (80 allocated to the control group and 80 to the intervention group) from 8 metropolitan community pharmacies located around Perth city center in Western Australia. All participants received standardized smoking cessation advice. The intervention group participants were also digitally photoaged by using the Internet-based APRIL Face Aging software so they could preview images of themselves as a lifelong smoker and as a nonsmoker. Due to the nature of the intervention, the participants and researcher could not be blinded to the study. The main outcome measure was quit attempts at 6-month follow-up, both self-reported and biochemically validated through testing for carbon monoxide (CO), and nicotine dependence assessed via the Fagerström scale.Results: At 6-month follow-up, 5 of 80 control group participants (6.3%) suggested they had quit smoking, but only 1 of 80 control group participants (1.3%) consented to, and was confirmed by, CO validation. In the intervention group, 22 of 80 participants (27.5%) reported quitting, with 11 of 80 participants (13.8%) confirmed by CO testing. This difference in biochemically confirmed quit attempts was statistically significant (χ21=9.0, P=.003). A repeated measures analysis suggested the average intervention group smoking dependence score had also significantly dropped compared to control participants (P<.001). These differences remained statistically significant after adjustment for small differences in gender distribution and nicotine dependence between the groups. The mean cost of implementing the intervention was estimated at AU 46 per additional quitter. The mean cost that participants indicated they were willing to pay for the digital aging service was AU $20.25 (SD 15.32). Conclusions: Demonstrating the detrimental effects on facial physical appearance by using a computer-generated simulation may be both effective and cost-effective at persuading young adult smokers to quit
How often does music and rhythm improve patients’ perception of motor symptoms in Parkinson’s disease?
Organizational Barriers to Oral Health Conversations Between Health Visitors and Parents of Children Aged 9–12 Months Old
Background: Dental caries is the most prevalent preventable childhood disease and a major public health priority. Local authorities in England have a statutory responsibility to improve child health, including oral health, through the “Healthy Child Programme.” The “Healthy Child Programme,” which includes the provision of oral health advice is delivered by health visitors to parents of young children. To date, research has mainly concentrated on individual interactions between health visitors and parents, with less attention given to the broader context in which these oral health conversations between health visitor and parents take place.
Objective: Our study explored the organizational factors that obstruct health visitors from engaging in meaningful conversations with parents about young children's oral health.
Methods: Qualitative interviews and focus groups were held with health visiting teams (n = 18) conducting home visits with parents of 9–12-month olds in a deprived, urban area in England.
Results: The study revealed the wide variation in what and how oral health advice is delivered to parents at home visits. Several barriers were identified and grouped into four key themes: (1) Priority of topics discussed in the home visits; (2) Finance cuts and limited resources; (3) Oral health knowledge and skills; and (4) Collaborative working with other professionals. It was evident that organizational factors in current public health policy and service provision play an important role in shaping oral health practices and opportunities for behavior change.
Conclusion: Organizational practices and procedures play an important role in creating interaction patterns between health visiting teams and parents of young children. They often limit effective engagement with and positive change in oral health. For future oral health interventions to be effective, awareness of these barriers is essential alongside them being founded on evidence-based advice and underpinned by appropriate theory
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