144 research outputs found
Understanding innovators' experiences of barriers and facilitators in implementation and diffusion of healthcare service innovations: A qualitative study
This article is made available through the Brunel Open Access Publishing Fund - Copyright @ 2011 Barnett et al.Background: Healthcare service innovations are considered to play a pivotal role in improving organisational efficiency and responding effectively to healthcare needs. Nevertheless, healthcare organisations encounter major difficulties in sustaining and diffusing innovations, especially those which concern the organisation and delivery of healthcare services. The purpose of the present study was to explore how healthcare innovators of process-based initiatives perceived and made sense of factors that either facilitated or obstructed the innovation implementation and diffusion. Methods: A qualitative study was designed. Fifteen primary and secondary healthcare organisations in the UK, which had received health service awards for successfully generating and implementing service innovations, were studied. In-depth, semi structured interviews were conducted with the organisational representatives who conceived and led the development process. The data were recorded, transcribed and thematically analysed. Results: Four main themes were identified in the analysis of the data: the role of evidence, the function of inter-organisational partnerships, the influence of human-based resources, and the impact of contextual factors. "Hard" evidence operated as a proof of effectiveness, a means of dissemination and a pre-requisite for the initiation of innovation. Inter-organisational partnerships and people-based resources, such as champions, were considered an integral part of the process of developing, establishing and diffusing the innovations. Finally, contextual influences, both intra-organisational and extra-organisational were seen as critical in either impeding or facilitating innovators' efforts. Conclusions: A range of factors of different combinations and co-occurrence were pointed out by the innovators as they were reflecting on their experiences of implementing, stabilising and diffusing novel service initiatives. Even though the innovations studied were of various contents and originated from diverse organisational contexts, innovators' accounts converged to the significant role of the evidential base of success, the inter-personal and inter-organisational networks, and the inner and outer context. The innovators, operating themselves as important champions and being often willing to lead constructive efforts of implementation to different contexts, can contribute to the promulgation and spread of the novelties significantly.This research was supported financially by the Multidisciplinary Assessment of
Technology Centre for Healthcare (MATCH)
Tailored ß-Cyclodextrin Blocks the Translocation Pores of Binary Exotoxins from C. Botulinum and C. Perfringens and Protects Cells from Intoxication
International audienceBackgroundClostridium botulinum C2 toxin and Clostridium perfringens iota toxin are binary exotoxins, which ADP-ribosylate actin in the cytosol of mammalian cells and thereby destroy the cytoskeleton. C2 and iota toxin consists of two individual proteins, an enzymatic active (A-) component and a separate receptor binding and translocation (B-) component. The latter forms a complex with the A-component on the surface of target cells and after receptor-mediated endocytosis, it mediates the translocation of the A-component from acidified endosomal vesicles into the cytosol. To this end, the B-components form heptameric pores in endosomal membranes, which serve as translocation channels for the A-components.Here we demonstrate that a 7-fold symmetrical positively charged ß-cyclodextrin derivative, per-6-S-(3-aminomethyl)benzylthio-ß-cyclodextrin, protects cultured cells from intoxication with C2 and iota toxins in a concentration-dependent manner starting at low micromolar concentrations. We discovered that the compound inhibited the pH-dependent membrane translocation of the A-components of both toxins in intact cells. Consistently, the compound strongly blocked transmembrane channels formed by the B-components of C2 and iota toxin in planar lipid bilayers in vitro. With C2 toxin, we consecutively ruled out all other possible inhibitory mechanisms showing that the compound did not interfere with the binding of the toxin to the cells or with the enzyme activity of the A-component.Conclusions/SignificanceThe described ß-cyclodextrin derivative was previously identified as one of the most potent inhibitors of the binary lethal toxin of Bacillus anthracis both in vitro and in vivo, implying that it might represent a broad-spectrum inhibitor of binary pore-forming exotoxins from pathogenic bacteria
Reduced Bone Mass and Muscle Strength in Male 5α-Reductase Type 1 Inactivated Mice
Androgens are important regulators of bone mass but the relative importance of testosterone (T) versus dihydrotestosterone (DHT) for the activation of the androgen receptor (AR) in bone is unknown. 5α-reductase is responsible for the irreversible conversion of T to the more potent AR activator DHT. There are two well established isoenzymes of 5α-reductase (type 1 and type 2), encoded by separate genes (Srd5a1 and Srd5a2). 5α-reductase type 2 is predominantly expressed in male reproductive tissues whereas 5α-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of 5α-reductase type 1 for bone mass using Srd5a1−/− mice. Four-month-old male Srd5a1−/− mice had reduced trabecular bone mineral density (−36%, p<0.05) and cortical bone mineral content (−15%, p<0.05) but unchanged serum androgen levels compared with wild type (WT) mice. The cortical bone dimensions were reduced in the male Srd5a1−/− mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05) in orchidectomized WT mice but not in orchidectomized Srd5a1−/− mice. Male Srd5a1−/− mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05). Female Srd5a1−/− mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, 5α-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of 5α-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1−/− mice, is an indirect effect mediated by elevated circulating androgen levels
A randomized controlled trial to prevent glycemic relapse in longitudinal diabetes care: Study protocol (NCT00362193)
BACKGROUND: Diabetes is a common disease with self-management a key aspect of care. Large prospective trials have shown that maintaining glycated hemoglobin less than 7% greatly reduces complications but translating this level of control into everyday clinical practice can be difficult. Intensive improvement programs are successful in attaining control in patients with type 2 diabetes, however, many patients experience glycemic relapse once returned to routine care. This early relapse is, in part, due to decreased adherence in self-management behaviors. OBJECTIVE: This paper describes the design of the Glycemic Relapse Prevention study. The purpose of this study is to determine the optimal frequency of maintenance intervention needed to prevent glycemic relapse. The primary endpoint is glycemic relapse, which is defined as glycated hemoglobin greater than 8% and an increase of 1% from baseline. METHODS: The intervention consists of telephonic contact by a nurse practitioner with a referral to a dietitian if indicated. This intervention was designed to provide early identification of self-care problems, understanding the rationale behind the self-care lapse and problem solve to find a negotiated solution. A total of 164 patients were randomized to routine care (least intensive), routine care with phone contact every three months (moderate intensity) or routine care with phone contact every month (most intensive). CONCLUSION: The baseline patient characteristics are similar across the treatment arms. Intervention fidelity analysis showed excellent reproducibility. This study will provide insight into the important but poorly understood area of glycemic relapse prevention
Induction of the GABA Cell Phenotype: An In Vitro Model for Studying Neurodevelopmental Disorders
Recent studies of the hippocampus have suggested that a network of genes is associated with the regulation of the GAD67 (GAD1) expression and may play a role in γ-amino butyric acid (GABA) dysfunction in schizophrenia (SZ) and bipolar disorder (BD). To obtain a more detailed understanding of how GAD67 regulation may result in GABAergic dysfunction, we have developed an in vitro model in which GABA cells are differentiated from the hippocampal precursor cell line, HiB5. Growth factors, such as PDGF, and BDNF, regulate the GABA phenotype by inducing the expression of GAD67 and stimulating the growth of cellular processes, many with growth cones that form appositions with the cell bodies and processes of other GAD67-positive cells. These changes are associated with increased expression of acetylated tubulin, microtubule-associated protein 2 (MAP2) and the post-synaptic density protein 95 (PSD95). The addition of BDNF, together with PDGF, increases the levels of mRNA and protein for GAD67, as well as the high affinity GABA uptake protein, GAT1. These changes are associated with increased concentrations of GABA in the cytoplasm of “differentiated” HiB5 neurons. In the presence of Ca2+ and K+, newly synthesized GABA is released extracellularly. When the HiB5 cells appear to be fully differentiated, they also express GAD65, parvalbumin and calbindin, and GluR subtypes as well as HDAC1, DAXX, PAX5, Runx2, associated with GAD67 regulation. Overall, these results suggest that the HiB5 cells can differentiate into functionally mature GABA neurons in the presence of gene products that are associated with GAD67 regulation in the adult hippocampus
Why Are Computational Neuroscience and Systems Biology So Separate?
Despite similar computational approaches, there is surprisingly little interaction between the computational neuroscience and the systems biology research communities. In this review I reconstruct the history of the two disciplines and show that this may explain why they grew up apart. The separation is a pity, as both fields can learn quite a bit from each other. Several examples are given, covering sociological, software technical, and methodological aspects. Systems biology is a better organized community which is very effective at sharing resources, while computational neuroscience has more experience in multiscale modeling and the analysis of information processing by biological systems. Finally, I speculate about how the relationship between the two fields may evolve in the near future
An immunohistochemical perspective of PPARβ and one of its putative targets PDK1 in normal ovaries, benign and malignant ovarian tumours
Peroxisome proliferator-activated receptor β (PPARβ) is a member of the nuclear hormone receptor family and is a ligand-activated transcription factor with few known molecular targets including 3-phosphoinositide-dependent protein kinase 1(PDK1). In view of the association of PPARβ and PDK1 with cancer, we have examined the expression of PPARβ and PDK1 in normal ovaries and different histological grades of ovarian tumours. Normal ovaries, benign, borderline, grades 1, 2 and 3 ovarian tumours of serous, muciuous, endometrioid, clear cell and mixed subtypes were analysed by immunohistochemistry for PPARβ and PDK1 expression. All normal ovarian tissues, benign, borderline and grade 1 tumours showed PPARβ staining localised in the epithelium and stroma. Staining was predominantly nuclear, but some degree of cytoplasmic staining was also evident. Approximately 20% of grades 2 and 3 tumours lacked PPARβ staining, whereas the rest displayed some degree of nuclear and cytoplasmic staining of the scattered epithelium and stroma. The extent of epithelial and stromal PPARβ staining was significantly different among the normal and the histological grades of tumours (χ2=59.25, d.f.=25, P<0.001; χ2=64.48, d.f.=25, P<0.001). Significantly different staining of PPARβ was observed in the epithelium and stroma of benign and borderline tumours compared with grades 1, 2 and 3 tumours (χ2=11.28, d.f.=4, P<0.05; χ2=16.15, d.f.=4, P<0.005). In contrast, PDK1 immunostaining was absent in 9 out of 10 normal ovaries. Weak staining for PDK1 was observed in one normal ovary and 40% of benign ovarian tumours. All borderline and malignant ovarian tumours showed positive cytoplasmic and membrane PDK1 staining. Staining of PDK1 was confined to the epithelium and the blood vessels, and no apparent staining of the stroma was evident. Significantly different PDK1 staining was observed between the benign/borderline and malignant ovarian tumours (χ2=22.45, d.f.=5, P<0.001). In some borderline and high-grade tumours, staining of the reactive stroma was also evident. Our results suggest that unlike the colon, the endometrial, head and neck carcinomas, overexpression of PPARβ does not occur in ovarian tumours. However, overexpression of PDK1 was evident in borderline and low- to high-grade ovarian tumours and is consistent with its known role in tumorigenesis
Outcomes for Implementation Research: Conceptual Distinctions, Measurement Challenges, and Research Agenda
An unresolved issue in the field of implementation research is how to conceptualize and evaluate successful implementation. This paper advances the concept of “implementation outcomes” distinct from service system and clinical treatment outcomes. This paper proposes a heuristic, working “taxonomy” of eight conceptually distinct implementation outcomes—acceptability, adoption, appropriateness, feasibility, fidelity, implementation cost, penetration, and sustainability—along with their nominal definitions. We propose a two-pronged agenda for research on implementation outcomes. Conceptualizing and measuring implementation outcomes will advance understanding of implementation processes, enhance efficiency in implementation research, and pave the way for studies of the comparative effectiveness of implementation strategies
Exploring the Gain of Function Contribution of AKT to Mammary Tumorigenesis in Mouse Models
Elevated expression of AKT has been noted in a significant percentage of primary human breast cancers, mainly as a consequence of the PTEN/PI3K pathway deregulation. To investigate the mechanistic basis of the AKT gain of function-dependent mechanisms of breast tumorigenesis, we explored the phenotype induced by activated AKT transgenes in a quantitative manner. We generated several transgenic mice lines expressing different levels of constitutively active AKT in the mammary gland. We thoroughly analyzed the preneoplastic and neoplastic mammary lesions of these mice and correlated the process of tumorigenesis to AKT levels. Finally, we analyzed the impact that a possible senescent checkpoint might have in the tumor promotion inhibition observed, crossing these lines to mammary specific p53(R172H) mutant expression, and to p27 knock-out mice. We analyzed the benign, premalignant and malignant lesions extensively by pathology and at molecular level analysing the expression of proteins involved in the PI3K/AKT pathway and in cellular senescence. Our findings revealed an increased preneoplastic phenotype depending upon AKT signaling which was not altered by p27 or p53 loss. However, p53 inactivation by R172H point mutation combined with myrAKT transgenic expression significantly increased the percentage and size of mammary carcinoma observed, but was not sufficient to promote full penetrance of the tumorigenic phenotype. Molecular analysis suggest that tumors from double myrAKT;p53(R172H) mice result from acceleration of initiated p53(R172H) tumors and not from bypass of AKT-induced oncogenic senescence. Our work suggests that tumors are not the consequence of the bypass of senescence in MIN. We also show that AKT-induced oncogenic senescence is dependent of pRb but not of p53. Finally, our work also suggests that the cooperation observed between mutant p53 and activated AKT is due to AKT-induced acceleration of mutant p53-induced tumors. Finally, our work shows that levels of activated AKT are not essential in the induction of benign or premalignant tumors, or in the cooperation of AKT with other tumorigenic signal such as mutant p53, once AKT pathway is activated, the relative level of activity seems not to determine the phenotype
Effect of Sanitation on Soil-Transmitted Helminth Infection: Systematic Review and Meta-Analysis
A systematic review and meta-analysis by Kathrin Ziegelbauer and colleagues finds that sanitation is associated with a reduced risk of transmission of helminthiases to humans
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