Abstract During cerebral ischemia, elevation of TNF-α and glutamate to pathophysiological levels may induce dysregulation of normal synaptic processes, leading ultimately to cell death. Previous studies have shown that patients subjected to a mild transient ischemic attack within a critical time window prior to a more severe ischemic episode may show attenuation in the clinical severity of the stroke and result in a more positive functional outcome. Studies with organotypic hippocampal cultures and mixed primary hippocampal cultures have shown that prior incubation with low concentrations of glutamate and TNF-α increase the resistance of neurones to a subsequent insult from glutamate, AMPA and NMDA, while co-exposure of TNF-α and for example AMPA may have neuroprotective effects compared to cultures exposed to excitotoxic agents alone. In addition our work has shown that although glutamate and TNF-α pretreatment induces analogous levels of desensitisation of the intracellular calcium dynamics of neurons under resting conditions and in response to acute glutamate stimulation, their downstream signalling pathways involved in this response do not converge. Glutamate and TNF-α would appear to have opposing effects on resting Ca2+ levels which supports the proposal that they have distinct modes of preconditioning.

Abstract Background For the purposes of this paper "weaning is defined as the introduction of the first solid foods to infants". Global recommendations by the World Health Organisation (WHO) recommend that all infants be exclusively breast-fed for the first six months of life. No global recommendations have been made for formula fed infants. In Europe it is recommended that weaning foods should be introduced between 18 weeks and 26 weeks regardless of whether infants are breast or formula fed. In the United Kingdom it is recommended that solids be introduced at around six-months for both breast and formula fed infants. In Ireland official guidelines recommend that breast fed infants should be introduced solids at 6 months of age while for formula fed infants the recommendation is for 4 months. The disparity between these global, European, UK and local recommendations may be a source of confusion for parents and health care professional based in Ireland. Emerging evidence suggests that babies in Ireland are given solid foods before the recommended age but there has been little investigation of the weaning advice provided by health professionals. Since community health professionals have routine parent interactions in the pre-weaning and early-weaning period and hence are in a unique position to positively influence parental weaning decisions, this study aimed to explore their knowledge, attitudes and advice practices about weaning. Methods A mixed-methods approach was used for the research, commencing with a multi-disciplinary focus group to guide and develop a questionnaire. Questionnaires were then distributed in a postal survey to General Practitioners (GPs) (n 179), Practice Nurses (PNs) (n 121), Public Health Nurses (PHNs) (n 107) and Community Dieticians (CDs) (n 8). Results The results indicate varying levels of knowledge of official weaning recommendations and a variety of advice practices. CDs and PHNs acknowledged a clear role in providing weaning advice while demonstrating high confidence levels in providing this advice. However, 19% of PNs and 7% of GP respondents did not acknowledge that they have a role in providing weaning advice to parents; even though Health Service Executive (HSE) written literature given to parents states that they should seek information from PNs and GPs. Conclusion Small pockets of misinformation about the introduction of solid foods persist amongst health professionals which may lead to inconsistent advice for parents. Further research is needed.