222 research outputs found
Cellular interactions with polystyrene nanoplastics-The role of particle size and protein corona.
Plastic waste is ubiquitously spread across the world and its smaller analogs-microplastics and nanoplastics-raise particular health concerns. While biological impacts of microplastics and nanoplastics have been actively studied, the chemical and biological bases for the adverse effects are sought after. This work explores contributory factors by combining results from in vitro and model mammalian membrane experimentation to assess the outcome of cell/nanoplastic interactions in molecular detail, inspecting the individual contribution of nanoplastics and different types of protein coronae. The in vitro study showed mild cytotoxicity and cellular uptake of polystyrene (PS) nanoplastics, with no clear trend based on nanoplastic size (20 and 200ânm) or surface charge. In contrast, a nanoplastic size-dependency on bilayer disruption was observed in the model system. This suggests that membrane disruption resulting from direct interaction with PS nanoplastics has little correlation with cytotoxicity. Furthermore, the level of bilayer disruption was found to be limited to the hydrophilic headgroup, indicating that transmembrane diffusion was an unlikely pathway for cellular uptake-endocytosis is the viable mechanism. In rare cases, small PS nanoplastics (20ânm) were found in the vicinity of chromosomes without a nuclear membrane surrounding them; however, this was not observed for larger PS nanoplastics (200ânm). We hypothesize that the nanoplastics can interact with chromosomes prior to nuclear membrane formation. Overall, precoating PS particles with protein coronae reduced the cytotoxicity, irrespective of the corona type. When comparing the two types, the extent of reduction was more apparent with soft than hard corona
Metabolic adaptability in metastatic breast cancer by AKR1B10-dependent balancing of glycolysis and fatty acid oxidation.
The different stages of the metastatic cascade present distinct metabolic challenges to tumour cells and an altered tumour metabolism associated with successful metastatic colonisation provides a therapeutic vulnerability in disseminated disease. We identify the aldo-keto reductase AKR1B10 as a metastasis enhancer that has little impact on primary tumour growth or dissemination but promotes effective tumour growth in secondary sites and, in human disease, is associated with an increased risk of distant metastatic relapse. AKR1B10High tumour cells have reduced glycolytic capacity and dependency on glucose as fuel source but increased utilisation of fatty acid oxidation. Conversely, in both 3D tumour spheroid assays and in vivo metastasis assays, inhibition of fatty acid oxidation blocks AKR1B10High-enhanced metastatic colonisation with no impact on AKR1B10Low cells. Finally, mechanistic analysis supports a model in which AKR1B10 serves to limit the toxic side effects of oxidative stress thereby sustaining fatty acid oxidation in metabolically challenging metastatic environments
An <i>In Vivo</i> Functional Screen Identifies JNK Signaling As a Modulator of Chemotherapeutic Response in Breast Cancer.
Chemotherapy remains the mainstay of treatment for advanced breast cancer; however, resistance is an inevitable event for the majority of patients with metastatic disease. Moreover, there is little information available to guide stratification of first-line chemotherapy, crucial given the common development of multidrug resistance. Here, we describe an in vivo screen to interrogate the response to anthracycline-based chemotherapy in a syngeneic metastatic breast cancer model and identify JNK signaling as a key modulator of chemotherapy response. Combining in vitro and in vivo functional analyses, we demonstrate that JNK inhibition both promotes tumor cell cytostasis and blocks activation of the proapoptotic protein Bax, thereby antagonizing chemotherapy-mediated cytotoxicity. To investigate the clinical relevance of this dual role of JNK signaling, we developed a proliferation-independent JNK activity signature and demonstrate high JNK activity to be enriched in triple-negative and basal-like breast cancer subtypes. Consistent with the dual role of JNK signaling in vitro, high-level JNK pathway activation in triple-negative breast cancers is associated both with poor patient outcome in the absence of chemotherapy treatment and, in neoadjuvant clinical studies, is predictive of enhanced chemotherapy response. These data highlight the potential of monitoring JNK activity as early biomarker of response to chemotherapy and emphasize the importance of rational treatment regimes, particularly when combining cytostatic and chemotherapeutic agents. Mol Cancer Ther; 16(9); 1967-78. ©2017 AACR
Primary Care Staff's Views and Experiences Related to Routinely Advising Patients about Physical Activity. A Questionnaire Survey
Background: United Kingdom public health policy has recently re-emphasised the role of primary health care professionals in tackling increasing levels of physical inactivity within the general population. However,
little is known about the impact that this has had in practice. This study explores Scottish primary care staff's knowledge, attitudes and experiences associated with advising patients about physical activity during
routine consultations.
Methods: A cross-sectional questionnaire survey of general practitioners (or family physicians), practice nurses and health visitors based in four health regions was conducted during 2004. The main outcome measures included: i) health professionals' knowledge of the current physical activity recommendations;
(ii) practice related to routine physical activity advising; and (iii) associated attitudes.
Results: Questionnaires were returned by 757 primary care staff (response rate 54%). Confidence and enthusiasm for giving advice was generally high, but knowledge of current physical activity recommendations was low. In general, respondents indicated that they routinely discuss and advise patients about physical activity regardless of the presenting condition. Health visitors and practice nurses
were more likely than general practitioners to offer routine advice.
Lack of time and resources were more likely to be reported as barriers to routine advising by general practitioners than other professional groups. However, health visitors and practice nurses were also more likely than general practitioners to believe that patients would follow their physical activity advice giving.
Conclusion: If primary health care staff are to be fully motivated and effective in encouraging and supporting the general population to become more physically active, policymakers and health professionals need to engage in efforts to: (1) improve knowledge of current physical activity recommendations and population trends amongst frontline primary care staff; and (2) consider the development of tools to support individual assessment and advice giving to suit individual circumstances. Despite the fact that this study found that system barriers to routine advising were less of a problem than other previous research has indicated, this issue still remains a challenge
Eugene â A Domain Specific Language for Specifying and Constraining Synthetic Biological Parts, Devices, and Systems
BACKGROUND: Synthetic biological systems are currently created by an ad-hoc, iterative process of specification, design, and assembly. These systems would greatly benefit from a more formalized and rigorous specification of the desired system components as well as constraints on their composition. Therefore, the creation of robust and efficient design flows and tools is imperative. We present a human readable language (Eugene) that allows for the specification of synthetic biological designs based on biological parts, as well as provides a very expressive constraint system to drive the automatic creation of composite Parts (Devices) from a collection of individual Parts. RESULTS: We illustrate Eugene's capabilities in three different areas: Device specification, design space exploration, and assembly and simulation integration. These results highlight Eugene's ability to create combinatorial design spaces and prune these spaces for simulation or physical assembly. Eugene creates functional designs quickly and cost-effectively. CONCLUSIONS: Eugene is intended for forward engineering of DNA-based devices, and through its data types and execution semantics, reflects the desired abstraction hierarchy in synthetic biology. Eugene provides a powerful constraint system which can be used to drive the creation of new devices at runtime. It accomplishes all of this while being part of a larger tool chain which includes support for design, simulation, and physical device assembly
Acceptability of the âMOVEdiabetesâ physical activity intervention in diabetes primary care settings in Oman: findings from participants and practitioners
A snapshot of the prevalence of physical activity amongst older, community dwelling people in Victoria, Australia: patterns across the 'young-old' and 'old-old'
BACKGROUND: Physical activity has a range of health benefits for older people. The aim of this study was to determine physical activity prevalence and attitudes amongst respondents to a trial screening survey. METHODS: A cross-sectional survey was conducted. Subjects were community dwelling older people aged â„ 65 years, recruited via general practices in Victoria, Australia. Participants completed a mailed screening tool containing the Geriatric Depression Scale, the Active Australia survey and the Physical Activity Readiness Questionnaire. RESULTS: Of 330 participants, 20% were â„ 80 years. Activity levels were similar to those reported in population studies. The proportion of participants reporting physical activity was greatest for the walking category, but decreased across categories of physical activity intensity. The oldest-old were represented at all physical activity intensity levels. Over half reported exercising at levels that, according to national criteria are, 'sufficient to attain health benefit'. A greater proportion of participants aged 85 years and older were unaware of key physical activity messages, compared to participants aged less than 85 years. CONCLUSION: Most population surveys do not provide details of older people across age categories. This survey provided information on the physical activity of people up to 91 years old. Physical activity promotion strategies should be tailored according to the individual's needs. A better understanding of the determinants of physical activity behaviour amongst older sub-groups is needed to tailor and target physical activity promotion strategies and programs to maximise physical activity related health outcomes for older people
Do financial incentives for delivering health promotion counselling work? Analysis of smoking cessation activities stimulated by the quality and outcomes framework
<p>Abstract</p> <p>Background</p> <p>A substantial fraction of UK general practitioners' salaries is now intended to reflect the quality of care provided. This performance-related pay system has probably improved aspects of primary health care but, using the observational data available, disentangling the impacts of different types of targets set within this unique payment system is challenging.</p> <p>Discussion</p> <p>Financial incentives undoubtedly influence GPs' activities, however, those aimed at encouraging GPs' delivery of health promotion counselling may not always have the effects intended. There is strong, observational evidence that targets and incentives intended to increase smoking cessation counselling by GPs have merely increased their propensity to record this activity in patients' medical records. The limitations of using financial incentives to stimulate the delivery of counselling in primary care are discussed and a re-appraisal of their use within UK GPs' performance-related pay system is argued for.</p> <p>Summary</p> <p>The utility of targets employed by the system for UK General Practitioners' performance related pay may be inappropriate for encouraging the delivery of health promotion counselling interventions. An evaluation of these targets is essential before they are further developed or added to.</p
In the Law We Trust; Some Thoughts on the âLegislative Gapâ in Legal Studies
The Legitimacy and Effectiveness of Law & Governance in a World of Multilevel Jurisdiction
Modeling of the high-performance PLD-based sectioning method for classification of the shape of optical object images
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