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101.

Background

Clinical practice guidelines have been a popular tool for the improvement of health care through the implementation of evidence from systematic research. Yet, it is increasingly clear that knowledge alone is insufficient to change practice. The social, cultural, and material contexts within which practice occurs may invite or reject innovation, complement or inhibit the activities required for success, and sustain or alter adherence to entrenched practices. However, knowledge translation (KT) models are limited in providing insight about how and why contextual contingencies interact, the causal mechanisms linking structural aspects of context and individual agency, and how these mechanisms influence KT. Another limitation of KT models is the neglect of methods to engage potential adopters of the innovation in critical reflection about aspects of context that influence practice, the relevance and meaning of innovation in the context of practice, and the identification of strategies for bringing about meaningful change.

Discussion

This paper presents a KT model, the Critical Realism and the Arts Research Utilization Model (CRARUM), that combines critical realism and arts-based methodologies. Critical realism facilitates understanding of clinical settings by providing insight into the interrelationship between its structures and potentials, and individual action. The arts nurture empathy, and can foster reflection on the ways in which contextual factors influence and shape clinical practice, and how they may facilitate or impede change. The combination of critical realism and the arts within the CRARUM model promotes the successful embedding of interventions, and greater impact and sustainability.

Conclusion

CRARUM has the potential to strengthen the science of implementation research by addressing the complexities of practice settings, and engaging potential adopters to critically reflect on existing and proposed practices and strategies for sustaining change.  相似文献   
102.
Neisseria meningitidis traversal across the blood-cerebrospinal fluid barrier is an essential step in the pathogenesis of bacterial meningitis. We have previously shown that invasion of human brain microvascular endothelial cells (HBMEC) by meningococci is mediated by bacterial outer membrane protein Opc that binds fibronectin, thereby anchoring the bacterium to the integrin alpha 5 beta 1-receptor on the endothelial cell surface. However, subsequent signal transduction mechanisms essential for or regulated by N. meningitidis adhesion and invasion, or HBMEC responses to N. meningitidis are unknown. In this report we investigated the role of c-Jun N-terminal kinases 1 and 2 (JNK1 and JNK2), p38 mitogen-activated (MAP) kinase and protein tyrosine kinases in endothelial-N. meningitidis interaction. Binding of meningococci to HBMEC phosphorylated and activated JNK1 and JNK2 and p38 MAPK as well as their direct substrates c-Jun and MAP kinase activated kinase-2 (MAPKAPK-2), respectively. Non-invasive meningococcal strains lacking opc gene (opc mutants and sequence type 11 complex meningococci) still activated p38 MAPK, however, failed to activate JNK. Inhibition of JNK1 and JNK2 significantly reduced internalization of N. meningitidis by HBMEC without affecting its adherence. Blocking the endothelial integrin alpha 5 beta 1 also decreased N. meningitidis-induced JNK activation in HBMEC. These findings indicate the crucial role of JNK signalling pathway in N. meningitidis invasion in HBMEC. In contrast, p38 MAPK pathway was important for the control of interleukin-6 (IL-6) and IL-8 release by HBMEC. Genistein, a protein tyrosine kinase inhibitor, decreased both invasion of N. meningitidis into HBMEC and IL-6 and IL-8 release, indicating that protein tyrosine kinases, which link signals from integrins to intracellular signalling pathways are essential for both bacterial internalization and cytokine secretion by HBMEC.  相似文献   
103.
The functionality of beta-galactosidase encoded by the E. coli lacZ gene as a reporter of gene expression in C. glabrata was investigated. C. glabrata/E. coli shuttle vectors were constructed, containing both a C. glabrata CEN-ARS cassette, to allow regular segregation and episomal replication of the plasmids, and the lacZ coding sequence of E. coli. The functionality of beta-galactosidase in C. glabrata was verified by inserting the promoter and the 5' coding region of the HIS3 gene from C. glabrata directionally upstream of the lacZ gene. By fusing the promoter of the copper-controlled MTII gene to the lacZ reporter, we showed that beta-galactosidase activity can be differentially induced in C. glabrata. beta-galactosidase reporter activities were detected qualitatively by an indirect filter assay and quantitatively from permeabilized cells.  相似文献   
104.
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106.
A central step in the pathogenesis of bacterial meningitis caused by Neisseria meningitidis (the meningococcus) is the interaction of the bacteria with cells of the blood-brain barrier. In the present study, we analysed the invasive potential of two strains representing hypervirulent meningococcal lineages of the ET-5 and ET-37 complex in human brain-derived endothelial cells (HBEMCs). In contrast to previous observations made with epithelial cells and human umbilical vein-derived endothelial cells (HUVECs), significant internalization of encapsulated meningococci by HBMECs was observed. However, this uptake was found only for the ET-5 complex isolate MC 58, and not for an ET-37 complex strain. Furthermore, the uptake of meningococci by HBMECs depended on the presence of human serum, whereas serum of bovine origin did not promote the internalization of meningococci in HBMECs. By mutagenesis experiments, we demonstrate that internalization depended on the expression of the opc gene, which is present in meningococci of the ET-5 complex, but absent in ET-37 complex meningococci. Chromatographic separation of human serum proteins revealed fibronectin as the uptake-promoting serum factor, which binds to HBMECs via alpha 5 beta 1 integrin receptors. These data provide evidence for unique molecular mechanisms of the interaction of meningococci with endothelial cells of the blood-brain barrier and contribute to our understanding of the pathogenesis of meningitis caused by meningococci of different clonal lineages.  相似文献   
107.
Development and acclimation of energy transduction were studied in seedlings of Chenopodium rubrum L. ecotype selection 184 (50° 10' N; 105° 35' W) in response to photomorphogenic and photoperiodic treatments. Dark respiration and photosynthetic capacity [nmol O2 (pair of cotyledons)−1 h−1] were measured with an oxygen electrode. Changes in chloroplast ultrastructure were analyzed concomitantly. After germination, seedlings were grown at constant temperature either in darkness or in continuous light (white, red, far-red and blue) or were subjected to diurnal cycles of light/dark or changes in light quality. Dark respiration was low in far-red light treated seedlings. In red light treated seedlings dark respiration was high and the mean value did not depend on fluence rate or photoperiod. Blue light stimulated transitorily and modulated dark respiration in photoperiodic cycles. Photosynthetic capacity was reduced by far-red light and increased by red light. In response to blue light photosynthetic capacity increased, with indications of a requirement for continuous energy input. Phytochrome and a separate blue light receptor seemed to be involved. In continuous red light a clear cut circadian rhythm of dark respiration was observed. Blue light had a specific effect on chloroplast structure.  相似文献   
108.
We have examined the role of cytoskeletal elements with respect to the formation and maintenance of viroplasmic centers (VCs) in Tipula iridescent virus (TIV)-infected mosquito Aedes albopictus (C6/36) cells. Filamentous systems consisting of microtubules and microfilaments were detected by immunofluorescence microscopy. Inoculation of cells with TIV resulted in an alteration of microtubule and microfilament organization whether or not VCs developed. The formation of short arrays of microtubules induced by taxol or the depolymerization of microtubules by colchicine, as observed by immunofluorescence microscopy, had no apparent effect upon the development of VCs as detected by Hoechst staining and electron microscopy. The dissolution of the actin-containing filamentous system by cytochalasin B also had no effect upon development. We conclude from these results that microtubules and microfilaments are not involved in the formation or maintenance of VCs in TIV-infected A. albopictus (C6/36) cells.  相似文献   
109.
Within the capsule gene complex (cps) of Neisseria meningitidis two functional regions B and C are involved in surface translocation of the cytoplasmically synthesized capsular polysaccharide, which is a homopolymer of α-2,8 polyneuraminic acid. The region-C gene products share characteristics with transporter proteins of the ABC (ATP-binding cassette) superfamily of active transporters. For analysis of the role of region B in surface translocation of the capsular polysaccharide we purified the polysaccharides of region B- and region C-defective Escherichia coli clones by affinity chromatography. The molecular weights of the polysaccharides were determined by gel filtration and the polysaccharides were analysed for phospholipid substitution by polyacrylamide gel electrophoresis and immunoblotting. The results indicate that the full-size capsular polysaccharide with a phospholipid anchor is synthesized intracellularly and that lipid modification is a strong requirement for translocation of the poly saccharide to the cell surface. Proteins encoded by region B are involved in phospholipid substitution of the capsular polysaccharide. Nucleotide sequence analysis of region B revealed two open reading frames, which encode proteins with molecular masses of 45.1 and 48.7 kDa.  相似文献   
110.
Neisseria gonorrhoeae synthesizes a rough lipopolysaccharide that does not contain any of the repetitive units characteristic of the smooth lipopolysaccharide of members of the family Enterobacteriaceae. Three gonococcal homologs of Salmonella serovar typhimurium genes involved in the synthesis of the rhamnose component of the repetitive subunits have been isolated. Gonococcal homologs for rfbB, rfbA, and rfbD were found downstream of the galE gene in a region of the chromosome which shows overall homology with the meningococcal capsule gene complex region D. Sequence alignment demonstrated that the gonococcal gene products have 69, 65, and 54% amino acid identity with the Salmonella proteins RfbB, RfbA, and RfbD. The gonococcal RfbB and RfbA amino acid sequences share even more identical residues (73 and 65%, respectively) with the amino acid sequences derived from Escherichia coli genes o355 and o292, respectively. These genes are clustered with the genes involved in the biosynthesis of enterobacterial common antigen, and o355 is listed in the GenBank and Swiss Protein data banks as rffE (encoding UDP-GlcNAc-2-epimerase). However, complementation studies demonstrated that o355 does not encode the enzyme UDP-GlcNAc-2-epimerase. Gonococcal strains constructed with null mutations in the rfbBAD genes were unchanged in lipopolysaccharide phenotype and in the synthesis of gonococcal carbohydrate-containing C antigen. We were unable to detect any changes in gonococcal phenotype with respect to lipopolysaccharide sialylation, monoclonal-antibody binding, serum sensitivity, or interaction with eukaryotic cells in vitro. We conclude that the absence of a homolog for rfbC precludes the existence of a functional dTDP-rhamnose biosynthesis pathway in the gonococcal strains examined and that these genes are only maintained in N. gonorrhoeae either because of the presence of the galE gene or because of another as yet unrecognized function.  相似文献   
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