Factors influencing the turnover of intensive care nurses.

Access to the intensive care unit (ICU) is often tortuous as there is a high incidence of bed closure due to staff shortage, a problem exacerbated by a high rate of turnover. It is proposed that the first step in addressing the problem is to explore the reasons why people leave, illuminating areas of policy and practice that would benefit from amendment. Given that the issues concerned are complex and contextual in nature, an open exploratory approach was adopted, whereby respondents were interviewed using open questions and given the freedom to shape their responses according to their perceptions of the problem. The transcripts of eleven interviews were analysed, with four themes emerging which represent the most dominant factors influencing the respondents' decision to leave. These included stresses related to the work; inadequate opportunity for professional development; recognition and respect of others and the implications of shift-work. It was concluded that there needs to be a greater awareness of the potential for nurses to become excessively stressed in the ICU environment; that a decentralized management style may help maintain motivation; that rostering systems need to retain flexibility; and that there is a requirement for greater incentives to pursue a career in intensive care.

Alpha-melanocyte-stimulating hormone reduces impact of proinflammatory cytokine and peroxide-generated oxidative stress on keratinocyte and melanoma cell lines.

We have previously shown that alpha-melanocyte-stimulating hormone (alpha-MSH) can oppose tumor necrosis factor alpha activation of NF-kappaB (1-2 h) and intercellular adhesion molecule 1 up-regulation (mRNA by 3 h and protein by 24 h) in melanocytes and melanoma cells. The present study reports on the ability of four MSH peptides to control intracellular peroxide levels and glutathione peroxidase (GPx) activity in pigmentary and nonpigmentary cells. In human HBL melanoma and HaCaT keratinocytes tumor necrosis factor alpha and H(2)O(2) both activated GPx in a time- and concentration-dependent manner (by 30-45 min). alpha-MSH peptides were found to inhibit the stimulated GPx activity and had biphasic dose-response curves. MSH 1-13 and MSH [Nle(4)-d-Phe(7)] achieved maximum inhibition at 10(-10) and 10(-12) m, respectively. Higher concentrations (10-100 fold) of MSH 4-10 and MSH 11-13 were required to produce equivalent levels of inhibition. alpha-MSH was also capable of reducing peroxide accumulation within 15 min, and again this inhibition was biphasic. The data support a role of alpha-MSH in acute protection of cells to oxidative/cytokine action that precedes NF-kappaB and GPx activation. The rapidity and potency of the response to alpha-MSH in pigmentary and nonpigmentary cells suggest this to be a central role of this peptide in cutaneous cells.

Citrate metabolism by human platelets.

As part of a study on the utilization of substrates by platelets in defined media the metabolism of citrate was measured, since citrate is a common anticoagulant of nearly all such media, and is also an intermediate of oxidative metabolism. Human platelets transferred from plasma to an artificial medium by gel filtration, were incubated with [14C]citrate at 22 degrees C and labelled carbon dioxide produced was measured during short-term incubations of 2 h. Citrate (1 mM) was oxidized to carbon dioxide at low (0.3 nmol per 10(9) platelets h-1) but significant rates, and the oxidation was decreased by the presence of an alternative substrate (acetate) in the medium. There was, however, no significant conversion of citrate to glycogen. It was calculated that under normal storage conditions of platelet concentrates for transfusion purposes, the amount of citrate used cannot decrease citrate concentrations sufficiently to bring about platelet activation.