A unitary participatory vision of nursing knowledge

This article responds to the calls by Margaret Newman for clarifying and expanding the nature of nursing knowledge. The unitary worldview proposed by Newman and the participatory worldview of action research are explicated, highlighting their respective major elements. A synthesis of unitary and participatory worldviews, grounded in a union of the elements of each, is proposed as a vision for the development of nursing knowledge. The unitary, participatory vision described offers the potential for inclusiveness and transcendence of previous perspectives of nursing knowledge.     

Effects of a novel antiplatelet agent in mural thrombogenesis on collagen-coated glass

A parallel plate flow chamber and an epifluorescence video microscopy system were used to investigate the inhibitory effect of a novel antiplatelet agent (GT-12), a carbamoylpiperidine congener, on surface platelet aggregation and on the kinetics of thrombus growth induced by collagen-coated glass under controlled flow. Both macroscopic and microscopic measurements revealed that increasing concentrations of the drug correspondingly decreased the reaction rate between platelets at the surface, thereby reducing thrombus rate of growth at the surface. Because of decreased platelet/platelet adhesion, there was some embolization of the larger thrombi near the inlet of the reactive surface. In the presence of GT-12, average thrombus size and number of platelets per thrombus were both strikingly lowered. In addition, the net rate of growth of individual thrombi decreased to zero after short exposure times (about 60 seconds), in sharp contrast to controls. In contrast to chlorpromazine, GT-12 was effective in inhibiting platelet aggregation and thrombus rate of growth at relatively low concentrations (less than 100 mumol/L) in whole blood. The drug's effectiveness relative to controls in impeding platelet/platelet interactions was found to increase with decreasing incubation time and increasing perfusion time.     

Interleukin 7 receptor functions by recruiting the tyrosine kinase p59fyn through a segment of its cytoplasmic tail.

Engagement of the cell surface receptor for interleukin 7 (IL-7R) provokes protein tyrosine phosphorylation, although the receptor lacks a kinase catalytic domain in its cytoplasmic tail. The molecular basis of this response is not known. Here we report that the IL-7R functions by recruiting p59fyn, an intracellular tyrosine kinase of the src family. Treatment of pre-B cells with IL-7 causes an enhancement of the catalytic activity of p59fyn, but not of the related kinase p62yes. IL-7-dependent stimulation of the enzyme phosphatidylinositol 3-kinase, a tyrosine kinase substrate, provides further evidence suggestive of p59fyn activation. We demonstrate that p59fyn forms part of a protein complex with the IL-7R. A chimeric receptor comprising the CD8 extracellular domain and the IL-7R cytoplasmic tail (CD8/IL-7R) recruits tyrosine kinase activity in transfected myeloma cells, and p59fyn can be detected in association with it by immunoprecipitation and immunoblotting. Conversely, p59fyn immunoprecipitates contain the phosphorylated CD8/IL-7R. We have identified a segment of the IL-7R cytoplasmic tail which mediates p59fyn recruitment: a truncated CD8/IL-7R containing only this segment recruits tyrosine kinase activity, associates with p59fyn, and activates phosphatidylinositol 3-kinase. Interestingly, this segment contains no tyrosine residues, although it is the phosphotyrosine-binding src homology domains of p59fyn and phosphatidylinositol 3-kinase which mediate their association with many growth factor receptors. Thus our results suggest that an unusual interaction links IL-7R to these two important signaling pathways.     

C-reactive protein, ESR, and klebsiella in ankylosing spondylitis.

Serum C reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured on 469 occasions in 149 patients with ankylosing spondylitis who had also been investigated for faecal carriage of klebsiella/enterobacter species on the same occasions. Raised values of CRP and ESR correlated with each other (P less than 0.001) as well as with clinically assessed active disease episodes (P less than 0.001). Patients with positive cultures for klebsiella were found to have higher mean values for CRP and ESR than those with negative cultures (P less than 0.025). CRP appears to be a useful marker of disease activity in ankylosing spondylitis.