Neuro-glial interactions in the adult rat retina after reaxotomy of ganglion cells: examination of neuron survival and phagocytic microglia using fluorescent tracers

Retinal ganglion cells (RGCs) regenerating through peripheral nerve grafts show enhanced survival after further axonal injury for at least 4 weeks [Restor. Neurol. Neurosci. 21 (2003) 11]. Here, we examined the survival of the neurons and their microglial phagocytosis in dependence of the site of reaxotomy. Therefore, the optic nerve in adult rats was transected at different distances from the eye cup and replaced with an autologous piece of sciatic nerve. After 14 days of axonal growth, the regenerated neurites were reaxotomized either within the remaining optic stump or within the graft and their cell bodies were retrogradely labeled. Reaxotomy of regenerated ganglion cells within the remaining optic nerve resulted in reduced (but not significant) ganglion cell survival and significant microglial phagocytosis in contrast to reaxotomy within the peripheral nerve graft. Furthermore, phagocytosis-dependent labeling using two different fluorescent tracers revealed that the same microglial cell can phagocytose further dying ganglion cells within 14 days after the first activation. The results suggest that the intrasciatic segments of axons receive some trophic support that is retrogradely transported and required to limit the microglial activation. The microglial capability to phagocytose dying neurons several fold emphasizes their function in permanent scavenging within the retina.     

Leg wound infection after coronary artery bypass grafting: a meta-analysis comparing minimally invasive versus conventional vein harvesting

The great saphenous vein remains the most commonly harvested conduit for revascularization in coronary artery bypass grafting (CABG). Our aim is to compare minimally invasive vein harvest techniques to conventional vein harvest with regards to leg wound infection rates. A meta-analysis of identified randomized controlled trials, reporting a comparison between the two techniques published between 1965 and 2002, was undertaken. The outcome of interest was leg wound infection. Fourteen randomized studies were identified and included in the meta-analysis. Our study revealed that wound infection was significantly lower in the minimally invasive vein harvest group (odds ratio 0.22 with 95% confidence intervals of 0.14 to 0.34). Our study suggests that using minimally invasive techniques might reduce leg wound infection rate following great saphenous vein harvesting for CABG. Further research is required to evaluate the potential benefits of minimally invasive vein harvesting techniques on the cost of postoperative care and quality of the harvested vein.     

Axillary artery to left anterior descending coronary artery bypass with an externally stented graft: a technical report

With the proliferation of minimally invasive cardiac surgery a number of alternative inflow sites for coronary artery bypass grafting have been utilized, especially in higher risk patients. The use of axillary-coronary artery bypass is a safe and effective alternative especially in the case of patients requiring redo coronary revascularization. However, the length and convoluted course of the axillary-coronary vein graft makes is susceptible to twisting, trauma and neointimal hyperplasia. We therefore report a case of an axillary-coronary artery bypass in a high risk patient in which a Dacron conduit was used to externally support and protect the vein graft to the left anterior descending artery. Surgical technique and considerations are presented and discussed.     

Does off-pump coronary artery bypass reduce the incidence of post-operative atrial fibrillation? A question revisited.

Atrial fibrillation (AF) is the most common post-operative complication in patients undergoing coronary artery bypass grafting, with an increased incidence associated with advancing age. This study aims to determine whether off-pump coronary artery bypass (OPCAB) reduces the incidence of AF in a generalized population (mean age <70 years). A meta-analysis was performed including all randomised and propensity score matched non-randomised studies published between 2001 and 2003 reporting a comparison between the two techniques in a generalised patient group (average age <70 years). The primary outcome of interest was post-operative AF. Sensitivity analysis was performed to evaluate consistency of the calculated treatment effect. Fourteen studies fulfilled our inclusion criteria, including a total of 16,505 subjects. The incidence of AF was 19% (1612/8265) in the off-pump group versus 24% (1976/8240) in the on-pump group. When considering only the 11 randomised studies (2207 subjects), we found a significant reduction in the incidence of post-operative AF in the off-pump group using a random-effect model (odds ratio (OR)=0.60, 95% confidence interval (CI)=0.45-0.82, and chi-square of heterogeneity=18.02, P=0.05). Sensitivity analysis highlighted one randomised study causing funnel plot asymmetry, exclusion of which resulted in a significant reduction in the incidence of post-operative AF in the off-pump group (OR=0.71, 95% CI=0.57-0.90), with a non-significant heterogeneity of 3.91 (P=0.92). When only studies of high quality were considered (898 patients), no significant difference was seen between on and off-pump groups (OR=0.78, 95% CI=0.57-1.07, and heterogeneity=0.53, P=0.91). This may be due to small number of patients in this group. Our results suggest that although OPCAB surgery may reduce the incidence of post-operative AF in a generalised population (age <70 years) this finding is not clearly supported by high quality randomised trials. Although previous evidence suggests that the incidence of post-operative AF is reduced in an elderly population (>70 years) with off-pump surgery, our results show that the evidence is less clear in a younger population group. The question of whether off-pump surgery in this patient group results in a lower rate of post-operative AF remains to be answered by further high quality randomised research.     

Sternal tuberculosis after coronary artery bypass graft surgery.

We report a case of sternal tuberculosis following sternotomy, which was performed during coronary artery bypass graft surgery. Although pre-operative evaluation revealed signs of asymptomatic tuberculosis of the lung, isoniazid chemoprophylaxis was not instituted, and the patient developed active tuberculosis in both the lung and sternum 5 y later.     

Equity in public health standards: a qualitative document analysis of policies from two Canadian provinces

ABSTRACT: INTRODUCTION: Promoting health equity is a key goal of many public health systems. However, little isknown about how equity is conceptualized in such systems, particularly as standards ofpractice are established. As part of a larger study examining the renewal of public health intwo Canadian provinces, Ontario and British Columbia (BC), we undertook an analysis ofrelevant public health documents related to equity. The aim of this paper is to discuss howequity is considered within documents that outline standards for public health. METHODS: A research team consisting of policymakers and academics identified key documents relatedto the public health renewal process in each province. The documents were analyzed usingconstant comparative analysis to identify key themes related to the conceptualization andintegration of health equity as part of public health renewal in Ontario and BC. Documentswere coded inductively with higher levels of abstraction achieved through multiple readings.Sets of questions were developed to guide the analysis throughout the process. RESULTS: In both sets of provincial documents health inequities were defined in a similar fashion, as theconsequence of unfair or unjust structural conditions. Reducing health inequities was anexplicit goal of the public health renewal process. In Ontario, addressing "prioritypopulations" was used as a proxy term for health equity and the focus was on existingprograms. In BC, the incorporation of an equity lens enhanced the identification of healthinequities, with a particular emphasis on the social determinants of health. In both, prioritywas given to reducing barriers to public health services and to forming partnerships withother sectors to reduce health inequities. Limits to the accountability of public health toreduce health inequities were identified in both provinces. CONCLUSION: This study contributes to understanding how health equity is conceptualized and incorporatedinto standards for local public health. As reflected in their policies, both provinces haveembraced the importance of reducing health inequities. Both conceptualized this as rooted instructural injustices and the social determinants of health. Differences in theconceptualization of health equity likely reflect contextual influences on the public healthrenewal processes in each jurisdiction.