Perisynaptic Schwann cells phagocytose nerve terminal debris in a mouse model of Guillain‐Barré syndrome

In mouse models of acute motor axonal neuropathy, anti‐ganglioside antibodies (AGAbs) bind to motor axons, notably the distal nerve, and activate the complement cascade. While complement activation is well studied in this model, the role of inflammatory cells is unknown. Herein we aimed to investigate the contribution of phagocytic cells including macrophages, neutrophils and perisynaptic Schwann cells (pSCs) to distal nerve pathology. To observe this, we first created a subacute injury model of sufficient duration to allow inflammatory cell recruitment. Mice were injected intraperitoneally with an anti‐GD1b monoclonal antibody that binds strongly to mouse motor nerve axons. Subsequently, mice received normal human serum as a source of complement. Dosing was titrated to allow humane survival of mice over a period of 3 days, yet still induce the characteristic neurological impairment. Behaviour and pathology were assessed in vivo using whole‐body plethysmography and post‐sacrifice by immunofluorescence and flow cytometry. ex vivo nerve‐muscle preparations were used to investigate the acute phagocytic role of pSCs following distal nerve injury. Following complement activation at distal intramuscular nerve sites in the diaphragm macrophage localisation or numbers are not altered, nor do they shift to a pro‐ or anti‐inflammatory phenotype. Similarly, neutrophils are not significantly recruited. Instead, ex vivo nerve‐muscle preparations exposed to AGAb plus complement reveal that pSCs rapidly become phagocytic and engulf axonal debris. These data suggest that pSCs, rather than inflammatory cells, are the major cellular vehicle for axonal debris clearance following distal nerve injury, in contrast to larger nerve bundles where macrophage‐mediated clearance predominates.     

Soluble cell adhesion molecules in gingival crevicular fluid in periodontal health and disease

BACKGROUND: Cell adhesion molecules (CAMs) are cell surface proteins involved in the binding of cells to each other, to endothelial cells, or to the extracellular matrix. The soluble forms of CAMs (sCAMs) are thought to be produced by proteolytic cleavage from the cell surface and are shed into the gingival crevicular fluid (GCF). The aim of this study was to investigate whether sCAMs, sICAM-1, sVCAM-1, and sE-Selectin were present in GCF in both periodontal health and disease and to examine their relationship with periodontal inflammation. METHODS: GCF was collected from a clinically healthy, a gingivitis, and a periodontitis site in 29 subjects with chronic periodontitis and from a single clinically healthy site in 22 subjects without chronic periodontitis. The volume of GCF was measured and each sample was analyzed for sCAMs by enzyme-linked immunosorbent assay (ELISA). The effect of treatment (oral hygiene instruction, scaling and root planing) on the levels of sCAMs in each site of the diseased group was also investigated. RESULTS: Statistically significant differences (P < 0.05) were found between the levels of sVCAM-1 in periodontal health and disease. These results indicate that changes in the levels of sCAMs may be a sensitive indicator to differentiate healthy sites from those with periodontitis. Statistically significant changes in the levels of sICAM-1 were recorded after treatment (P < 0.05). CONCLUSIONS: Further studies are required to establish if these potential biomarkers will enable the identification of those sites most at risk for disease progression and also evaluate the response to treatment, thereby playing a preventive role in the pathogenesis of periodontal disease.     

Using action research to construct national evidence-based nursing care guidance for gerontological nursing

Aim. This paper explores the development of a low‐cost, involving methodology for constructing nursing‐focused evidence‐based national care guidance, known as Best Practice Statements, the intended users of which are gerontological nurses practising throughout Scotland. Design. The Best Practice Statement construction methodology forms one cycle in a five‐year longitudinal action research study that aims to achieve evidence‐based nursing, facilitate professional networking to support practice development and promote the principles and practice of gerontological nursing. Achieving these aims involved designing a virtual Practice Development College. Methods. A Community of Practice comprising practising gerontological nurses, expert advisors, academic teaching and research nurses collaborated in face‐to‐face meetings and in the virtual Practice Development College to delineate and refine the procedural model for Best Practice Statement construction. Focus groups, telephone interviews, analysis of on‐line archives and documentary outputs formed the analytic dataset. Results. Qualitative analysis indicated that, from the perspective of the community of practice, the emerging methodology facilitated the melding of knowledge sources reflecting the dominant evidence hierarchy with other forms of evidence valued by gerontological nurses, in the Best Practice Statement. Relevance to clinical practice. Current methods of care guidance construction rarely address the concerns of nurses and the evidence from which guidelines are developed is narrowly defined with regard to inclusion and acceptability. In contrast this model focuses on nursing issues, embraces a wider definition of evidence and ensures that the published Best Practice Statements are credible and achievable in gerontological practice, where they are tested and refined as an inherent aspect of the development process.     

Reversal theory states and cigarette availability predict lapses during smoking cessation among adolescents

Although 67% of adolescent smokers say they want to quit, only 7% are able to do so. The purpose of this study was to use metamotivational states as described in reversal theory to predict whether adolescents who are trying to quit smoking will lapse (smoke a cigarette) or will resist smoking in highly tempting situations. Reversal theory holds that individuals switch between telic (serious-minded) and paratelic (playful) metamotivational states. Questionnaires and semistructured interviews were administered to 62 adolescents ages 14-19 who had participated in a smoking cessation program. Interviews were coded according to the Metamotivational State Interview and Coding Schedule, and the resulting data were analyzed using logistic regression analysis. Adolescents in the paratelic metamotivational state (OR = 15.34; 95% CI: 5.3, 43.6) or with cigarettes readily available (OR = 4.6; 95% CI: 1.6, 13.2) were more likely to lapse than were adolescents in the telic state or who required effort to obtain cigarettes. The variables telic/paratelic state and cigarette availability accurately predicted the outcome of highly tempting situations 80% of the time. Using reversal theory constructs to develop state-specific strategies shows promise as an additional tool for those in this age group coping with the temptation to smoke.