Hypercapnia induces cleavage and nuclear localization of RelB protein, giving insight into CO2 sensing and signaling

Carbon dioxide (CO(2)) is increasingly being appreciated as an intracellular signaling molecule that affects inflammatory and immune responses. Elevated arterial CO(2) (hypercapnia) is encountered in a range of clinical conditions, including chronic obstructive pulmonary disease, and as a consequence of therapeutic ventilation in acute respiratory distress syndrome. In patients suffering from this syndrome, therapeutic hypoventilation strategy designed to reduce mechanical damage to the lungs is accompanied by systemic hypercapnia and associated acidosis, which are associated with improved patient outcome. However, the molecular mechanisms underlying the beneficial effects of hypercapnia and the relative contribution of elevated CO(2) or associated acidosis to this response remain poorly understood. Recently, a role for the non-canonical NF-?B pathway has been postulated to be important in signaling the cellular transcriptional response to CO(2). In this study, we demonstrate that in cells exposed to elevated CO(2), the NF-?B family member RelB was cleaved to a lower molecular weight form and translocated to the nucleus in both mouse embryonic fibroblasts and human pulmonary epithelial cells (A549). Furthermore, elevated nuclear RelB was observed in vivo and correlated with hypercapnia-induced protection against LPS-induced lung injury. Hypercapnia-induced RelB processing was sensitive to proteasomal inhibition by MG-132 but was independent of the activity of glycogen synthase kinase 3ß or MALT-1, both of which have been previously shown to mediate RelB processing. Taken together, these data demonstrate that RelB is a CO(2)-sensitive NF-?B family member that may contribute to the beneficial effects of hypercapnia in inflammatory diseases of the lung.

Vascular endothelial growth factor promotes physical wound repair and is anti-apoptotic in primary distal lung epithelial and A549 cells

Objective: There is evidence to suggest a beneficial role for growth factors, including vascular endothelial growth factor (VEGF), in tissue repair and proliferation after injury within the lung. Whether this effect is mediated predominantly by actions on endothelial cells or epithelial cells is unknown. This study tested the hypothesis that VEGF acts as an autocrine trophic factor for human adult alveolar epithelial cells and that under situations of pro-apoptotic stress, VEGF reduces cell death. Design: In vitro cell culture study looking at the effects of 0.03% H2O2 on both A549 and primary distal lung epithelial cells.Measurement and Main Results: Primary adult human distal lung epithelial cells express both the soluble and membrane-associated VEGF isoforms and VEGF receptors 1 and 2. At physiologically relevant doses, soluble VEGF isoforms stimulate wound repair and have a proliferative action. Specific receptor ligands confirmed that this effect was mediated by VEGF receptor 1. In addition to proliferation, we demonstrate that VEGF reduces A549 and distal lung epithelial cell apoptosis when administered after 0.03% H2O2 injury. This effect occurs due to reduced caspase-3 activation and is phosphatidylinositol 3′–kinase dependent. Conclusion: In addition to its known effects on endothelial cells, VEGF acts as a growth and anti-apoptotic factor on alveolar epithelial cells. VEGF treatment may have potential as a rescue therapy for diseases associated with alveolar epithelial damage such as acute respiratory distress syndrome.

Exploring the experiences of nurses who care for children who have Acute Life Threatening Events (ALTE) in hospital

This thesis presents a program of work designed to explore and describe what the experience of caring for a child who has an Acute Life Threatening Event (ALTE) is like for the nurses. An ALTE may include a cardiac arrest, respiratory arrest or unplanned admission for a ward to the Paediatric Intensive Care unit. Using the MRC framework for the development of complex interventions, this information was then coupled with theory to develop the PREPARE and SUPPORT interventions. Given the wide-ranging and exploratory nature of this research, a pragmatic, mixed design approach was used to address the aims and objectives of the thesis. The mixed design approach included: a systematic literature review; international survey of practice; interviews with nurses and doctors using Interpretative Phenomenological Analysis; development, refinement and evaluation of interventions during a feasibility study. Two studies were identified through the systematic review which aimed to evaluate the effectiveness of debriefing. The studies did not provide evidence to support the use of these interventions within healthcare. The international survey of practice demonstrated hospitals were using interventions to both prepare and support nurses for these events. The preparatory interventions were clinically focused and the majority of the supportive interventions included a debrief. The interventions were not being evaluated for effectiveness. The interviews conducted with nurses and doctors provided insight into what that experience was like for the participants. Using the MRC framework, this evidence was coupled with theory to develop the PREPARE and SUPPORT interventions. A multidisciplinary working party used an iterative process to refine and evaluate the interventions and study procedures were explored through a feasibility study. The pragmatic, mixed design approach demonstrated how the empirical evidence was coupled with theory and clinical expertise to develop interventions for use within the healthcare environment.

Managing crisis:the role of primary care for people with serious mental illness

Background and Objectives: More than 30% of patients with serious mental illness in the United Kingdom now receive all their health care solely from primary care. This study explored the process of managing acute mental health crises from the dual perspective of patients and primary care health professionals. Methods: Eighteen focus groups involving 45 patients, 39 general practitioners, and eight practice nurses were held between May and November 2002 in six Primary Care Trusts across the British West Midlands. The topic guide explored perceptions of gold standard care, current issues and critical incidents in receiving/providing care, and ideas on improving services. Results: Themes relevant to the management of acute crisis included issues of process, such as access, advocacy, communication, continuity, and coordination of care; the development of more structured care that might reduce the need for crisis responses; and issues raised by the development of a more structured approach to care. Conclusions: Access to services is a complicated yet crucial feature of managing care in a crisis, with patients identifying barriers at the level of primary care and health professionals at the interface with secondary care. The development of more structured systems as a solution may generate its own ethical and pragmatic challenges.

Interventions for nurses caring for a child who has an unexpected acute life threatening event (ALTE) in hospital

Introduction: Caring for a child who has an unexpected ALTE in hospital can be stressful. An ALTE may include a cardiac arrest, respiratory arrest or call for immediate assistance. An international survey of practice was conducted to identify any existing interventions to inform a PhD program of work aimed at reducing the stress from these events through preparation and support. Purpose: The purpose of the survey was threefold: (1) Describe ‘normal’ practice when it comes to preparing staff or providing psychological support after caring for a child who has had an ALTE. (2) Determine if there are any interventions to prepare clinical staff for potential psychological effects of caring for a child who has an ALTE. (3) Determine if there are any interventions to provide support for clinical staff after caring for a child who has an ALTE. Material - Methods: An 18 item semi structured questionnaire was designed for the study to allow respondent to describe practices within their institution and outline their opinions and professional experiences. Clinicians from selected children’s and adult hospitals in Australia, Canada, New Zealand, United Kingdom and the United States of America were contacted by telephone. Following consent they were given the option to complete the survey via the telephone, by post or online. Results: Of the 61 hospitals approached 44 (72%) clinicians responded. Eighteen (41%) respondents identified interventions in place to prepare nurses for an ALTE ranging from (but not limited to) ad hoc discussions during life support training through to structured simulation training. Thirty-six (82%) respondents identified that they had interventions in place to support nurses after an ALTE ranging from (but not limited to) debriefing through to structured case reviews. Conclusions: Interventions varied across institutions, with no outcome or evaluation data for the interventions published to date.