102 research outputs found

    A novel 3D human glioblastoma cell culture system for modeling drug and radiation responses

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    Background. Glioblastoma (GBM) is the most common primary brain tumor, with dismal prognosis. The failure of drug–radiation combinations with promising preclinical data to translate into effective clinical treatments may relate to the use of simplified 2-dimensional in vitro GBM cultures. Methods. We developed a customized 3D GBM culture system based on a polystyrene scaffold (Alvetex) that recapitulates key histological features of GBM and compared it with conventional 2D cultures with respect to their response to radiation and to molecular targeted agents for which clinical data are available. Results. In 3 patient-derived GBM lines, no difference in radiation sensitivity was observed between 2D and 3D cultures, as measured by clonogenic survival. Three different molecular targeted agents, for which robust clinical data are available were evaluated in 2D and 3D conditions: (i) temozolomide, which improves overall survival and is standard of care for GBM, exhibited statistically significant effects on clonogenic survival in both patient-derived cell lines when evaluated in the 3D model compared with only one cell line in 2D cells; (ii) bevacizumab, which has been shown to increase progression-free survival when added to standard chemoradiation in phase III clinical trials, exhibited marked radiosensitizing activity in our 3D model but had no effect on 2D cells; and (iii) erlotinib, which had no efficacy in clinical trials, displayed no activity in our 3D GBM model, but radiosensitized 2D cells. Conclusions. Our 3D model reliably predicted clinical efficacy, strongly supporting its clinical relevance and potential value in preclinical evaluation of drug–radiation combinations for GBM

    Perspectives of healthcare providers on the nutritional management of patients on haemodialysis in Australia: An interview study

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    Objective To describe the perspectives of healthcare providers on the nutritional management of patients on haemodialysis, which may inform strategies for improving patient-centred nutritional care. Design Face-to-face semistructured interviews were conducted until data saturation, and thematic analysis based on principles of grounded theory. Setting 21 haemodialysis centres across Australia. Participants 42 haemodialysis clinicians (nephrologists and nephrology trainees (15), nurses (12) and dietitians (15)) were purposively sampled to obtain a range of demographic characteristics and clinical experiences. Results Six themes were identified: responding to changing clinical status (individualising strategies to patient needs, prioritising acute events, adapting guidelines), integrating patient circumstances (assimilating life priorities, access and affordability), delineating specialty roles in collaborative structures (shared and cohesive care, pivotal role of dietary expertise, facilitating access to nutritional care, perpetuating conflicting advice and patient confusion, devaluing nutritional specialty), empowerment for behaviour change (enabling comprehension of complexities, building autonomy and ownership, developing self-efficacy through engagement, tailoring self-management strategies), initiating and sustaining motivation (encountering motivational hurdles, empathy for confronting life changes, fostering non-judgemental relationships, emphasising symptomatic and tangible benefits, harnessing support networks), and organisational and staffing barriers (staffing shortfalls, readdressing system inefficiencies). Conclusions Organisational support with collaborative multidisciplinary teams and individualised patient care were seen as necessary for developing positive patient-clinician relationships, delivering consistent nutrition advice, and building and sustaining patient motivation to enable change in dietary behaviour. Improving service delivery and developing and delivering targeted, multifaceted self-management interventions may enhance current nutritional management of patients on haemodialysis

    Evaluation of four different small animal radiation plans on tumour and normal tissue dosimetry in a glioblastoma mouse model

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    Objective: Small animal radiotherapy research platforms such as XStrahl’s SARRP enable more precise irradiation of tumours and normal tissues in pre-clinical models of cancer. Using an orthotopic G7 glioblastoma xenograft model we studied the impact of four different radiotherapy plans on tumour and normal tissue dosimetry. Methods: Plans were created using four different approaches (single beam, parallel opposed pair, single plane arcs, couch rotation arcs) and dose volume histograms (DVH) for the tumour and the relevant organs at risk (OARs) (mouth, ipsilateral brain, contralateral brain, brain stem) were compared for a sample mouse subject. To evaluate the accuracy of delivery, treatment plans were recreated in solid-water phantoms and delivered to radiochromic film. Results: Favourable tumour dosimetry was achieved by all plans. DVH analysis showed that different plans could be used to spare specific OARs depending on the objectives of the study. The delivery accuracy of the various treatments was better than 2%/2mm (dose difference/distance to agreement) in terms of global γ analysis. Conclusion: Small animal radiotherapy research platforms are an exciting addition to the pre-clinical research environment. Such systems improve the conformality of irradiation of tumours and OARs while maintaining a high degree of accuracy and enable investigators to optimise experiments in terms of tumour coverage and inclusion or exclusion of relevant OARs. Advances in knowledge: This study confirms the utility of the SARRP in terms of the accuracy of plan delivery, and informs decisions on treatment planning to optimise the clinical relevance and scientific value of experiments

    eHealth interventions for people with chronic kidney disease

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    This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: This review aims to look at the benefits and harms of using eHealth interventions in the CKD population

    Interventions for improving health literacy in people with chronic kidney disease

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    This is the protocol for a review and there is no abstract. The objectives are as follows: This review aims to look at the benefits and harms of interventions for improving health literacy in patients with CKD

    Un hameau du Ve s. av. J.‑C. en Minervois : la Condamine (Villeneuve-Minervois, Aude)

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    Fouillé en 2008 dans le cadre d’une opération archéologique préventive sur la commune de Villeneuve-Minervois par Oxford Archéologie Méditerranée, le site de la Condamine correspond à un établissement rural dont l’occupation est centrée sur le Ve s. av. J.‑C. Les éléments architecturaux témoignent de la présence de constructions à ossatures de bois. Un examen de la répartition et de l’agencement des négatifs de poteaux permet de restituer la trame d’un hameau s’organisant autour d’un noyau principal réunissant des habitations, au nord et au sud desquelles se développent des petites constructions, correspondant pour certaines peut-être à des greniers. Deux séquences constructives se sont succédées. L’une d’elle concerne un vaste édifice bi-absidial, l’autre des bâtiments à plan quadrangulaire. D’autres structures liées au fonctionnement de l’occupation ont été mises au jour, notamment un foyer en fosse, un four et une carrière d’extraction d’argile.Excavated in 2008 thanks to a preventive archaeological operation in the municipality of Villeneuve-Minervois by Oxford Archéologie Méditerrannée, this site of La Condamine consists in a rural settlement occupied around the 5th century BC. The architectural elements testify of a presence of woodframe constructions. Analysing the distribution and the layout of the poles’ negatives allows to restore the frame of a hamlet. It is organised around a core of residential units with small constructions in their North and South. Some of the latter may correspond to granaries. Two periods of building have followed one another : one relative to a vast bi-apsidal edifice, the other to quadrangular buildings. Other structures linked to the functioning of the settlement have been uncovered, in particular a fireplace situated in a pit, an oven and a clay quarry

    Dynamic telomerase gene suppression via network effects of GSK3 inhibition

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    <b>Background</b>: Telomerase controls telomere homeostasis and cell immortality and is a promising anti-cancer target, but few small molecule telomerase inhibitors have been developed. Reactivated transcription of the catalytic subunit hTERT in cancer cells controls telomerase expression. Better understanding of upstream pathways is critical for effective anti-telomerase therapeutics and may reveal new targets to inhibit hTERT expression. <b>Methodology/Principal Findings</b>: In a focused promoter screen, several GSK3 inhibitors suppressed hTERT reporter activity. GSK3 inhibition using 6-bromoindirubin-3′-oxime suppressed hTERT expression, telomerase activity and telomere length in several cancer cell lines and growth and hTERT expression in ovarian cancer xenografts. Microarray analysis, network modelling and oligonucleotide binding assays suggested that multiple transcription factors were affected. Extensive remodelling involving Sp1, STAT3, c-Myc, NFκB, and p53 occurred at the endogenous hTERT promoter. RNAi screening of the hTERT promoter revealed multiple kinase genes which affect the hTERT promoter, potentially acting through these factors. Prolonged inhibitor treatments caused dynamic expression both of hTERT and of c-Jun, p53, STAT3, AR and c-Myc. <b>Conclusions/Significance</b>: Our results indicate that GSK3 activates hTERT expression in cancer cells and contributes to telomere length homeostasis. GSK3 inhibition is a clinical strategy for several chronic diseases. These results imply that it may also be useful in cancer therapy. However, the complex network effects we show here have implications for either setting

    Targeted, structured text messaging to improve dietary and lifestyle behaviours for people on maintenance haemodialysis (KIDNEYTEXT): Study protocol for a randomised controlled trial

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    Introduction Managing nutrition is critical for reducing morbidity and mortality in patients on haemodialysis but adherence to the complex dietary restrictions remains problematic. Innovative interventions to enhance the delivery of nutritional care are needed. The aim of this phase II trial is to evaluate the feasibility and effectiveness of a targeted mobile phone text messaging system to improve dietary and lifestyle behaviours in patients on long-term haemodialysis. Methods and analysis Single-blinded randomised controlled trial with 6 months of follow-up in 130 patients on haemodialysis who will be randomised to either standard care or KIDNEYTEXT. The KIDNEYTEXT intervention group will receive three text messages per week for 6 months. The text messages provide customised dietary information and advice based on renal dietary guidelines and general healthy eating dietary guidelines, and motivation and support to improve behaviours. The primary outcome is feasibility including recruitment rate, drop-out rate, adherence to renal dietary recommendations, participant satisfaction and a process evaluation using semistructured interviews with a subset of purposively sampled participants. Secondary and exploratory outcomes include a range of clinical and behavioural outcomes and a healthcare utilisation cost analysis will be undertaken. Ethics and dissemination The study has been approved by the Western Sydney Local Health District Human Research Ethics Committee-Westmead. Results will be presented at scientific meetings and published in peer-reviewed publications. Trial registration number ACTRN12617001084370; Pre-results

    Social Services Will Not Touch us with a Barge Pole’: Social Care Provision for Older Prisoners

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    Older prisoners are the fastest growing subgroup in the English and Welsh prison estate. Older prisoners have high levels of health and social care needs. This mixed method study involved the distribution of a questionnaire examining the availability of health and social care services for older prisoners to all prisons housing adult males in England and Wales, followed by qualitative telephone interviews with representatives from eight prisons. Over half of establishments had some contact with external social care services but reported significant difficulties in arranging care for individuals. A professional lead for older prisoners had been identified in 81% of establishments; however the value of this role to positively affect practice appeared questionable. Statutory social care was often non-existent in prison due to the lack of understanding of what it constituted and who was responsible for its provision

    Regulation of DNA double strand break repair by EGF and VEGF signalling reveals Akt to be a critical therapeutic target in glioblastoma

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    Glioblastoma (GBM) is currently incurable. Its radioresistance has been attributed to a subpopulation of cells termed ‘GBM stem-like cells’ characterised by multipotentiality and tumorigenicity. The discrepancy between pre-clinical and clinical effects of molecular targeted agents on radiosensitivity indicates that 2D in vitro models of GBM do not recapitulate the clinical scenario. In a 3D model developed in our laboratory, EGFR inhibitors failed to enhance radiosensitivity recapitulating their lack of efficacy in the clinic, contrasting with their radiosensitising activity in 2D cultures. Conversely, inhibition of VEGF signalling caused significant radiosensitisation of 3D cultures but had no effect in 2D conditions. The critical role of the DNA damage response in mediating these effects is illustrated by the consistent correlation between radiosensitivity, unrepaired double-strand breaks (γH2AX foci), mitotic catastrophe and micronuclei in both 2D and 3D models. Further investigation revealed unrepaired DSB to be associated with delayed resolution of phosphorylated DNA-PKcs nuclear foci and reduced formation of Rad51 foci. Hence in 2D conditions, EGFR signalling appeared to promote efficient non-homologous end-joining (NHEJ) repair, while in 3D conditions this process was dependent on VEGF signalling. Motivated by previous reports that radiation induced EGFR signalling promotes NHEJ via Akt mediated phosphorylation of DNA-PKcs, we investigated the role of Akt signalling in 2D and 3D systems. Specific inhibition of Akt using the small molecule inhibitor MK-2206 or Akti knockdown increased radiation sensitivity in both 2D and 3D models to a similar extent as EGFR or VEGF inhibition respectively. In keeping with this, phosphorylation of Akt was EGFR dependent in 2D GSC cultures but VEGF dependent in the 3D model. MK-2206 induced radiosensitivity was correlated with increased unrepaired DSBs and extended mouse survival in an U87MGLuc2 orthotopic model compared to radiation only. Our data identify Akt as a promising therapeutic target in combination with radiation for GBM
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