HL-1 cells express an inwardly rectifying K+ current activated via muscarinic receptors comparable to that in mouse atrial myocytes

An inwardly rectifying K^+ current is present in atrial cardiac myocytes that is activated by acetylcholine (I_{KACh}). Physiologically, activation of the current in the SA node is important in slowing the heart rate with increased parasympathetic tone. It is a paradigm for the direct regulation of signaling effectors by the Gβγ G-protein subunit. Many questions have been addressed in heterologous expression systems with less focus on the behaviour in native myocytes partly because of the technical difficulties in undertaking comparable studies in native cells. In this study, we characterise a potassium current in the atrial-derived cell line HL-1. Using an electrophysiological approach, we compare the characteristics of the potassium current with those in native atrial cells and in a HEK cell line expressing the cloned Kir3.1/3.4 channel. The potassium current recorded in HL-1 is inwardly rectifying and activated by the muscarinic agonist carbachol. Carbachol-activated currents were inhibited by pertussis toxin and tertiapin-Q. The basal current was time-dependently increased when GTP was substituted in the patch-clamp pipette by the non-hydrolysable analogue GTPγS. We compared the kinetics of current modulation in HL-1 with those of freshly isolated atrial mouse cardiomyocytes. The current activation and deactivation kinetics in HL-1 cells are comparable to those measured in atrial cardiomyocytes. Using immunofluorescence, we found GIRK4 at the membrane in HL-1 cells. Real-time RT-PCR confirms the presence of mRNA for the main G-protein subunits, as well as for M2 muscarinic and A1 adenosine receptors. The data suggest HL-1 cells are a good model to study IKAch

The role of the RACK1 ortholog Cpc2p in modulating pheromone-induced cell cycle arrest in fission yeast

The detection and amplification of extracellular signals requires the involvement of multiple protein components. In mammalian cells the receptor of activated C kinase (RACK1) is an important scaffolding protein for signal transduction networks. Further, it also performs a critical function in regulating the cell cycle by modulating the G1/S transition. Many eukaryotic cells express RACK1 orthologs, with one example being Cpc2p in the fission yeast Schizosaccharomyces pombe. In contrast to RACK1, Cpc2p has been described to positively regulate, at the ribosomal level, cells entry into M phase. In addition, Cpc2p controls the stress response pathways through an interaction with Msa2p, and sexual development by modulating Ran1p/Pat1p. Here we describe investigations into the role, which Cpc2p performs in controlling the G protein-mediated mating response pathway. Despite structural similarity to Gβ-like subunits, Cpc2p appears not to function at the G protein level. However, upon pheromone stimulation, cells overexpressing Cpc2p display substantial cell morphology defects, disorientation of septum formation and a significantly protracted G1 arrest. Cpc2p has the potential to function at multiple positions within the pheromone response pathway. We provide a mechanistic interpretation of this novel data by linking Cpc2p function, during the mating response, with its previous described interactions with Ran1p/Pat1p. We suggest that overexpressing Cpc2p prolongs the stimulated state of pheromone-induced cells by increasing ste11 gene expression. These data indicate that Cpc2p regulates the pheromone-induced cell cycle arrest in fission yeast by delaying cells entry into S phase

A participatory action research approach to strengthening health managers’ capacity at district level in Eastern Uganda

BACKGROUND: Many approaches to improving health managers’ capacity in poor countries, particularly those pursued by external agencies, employ non-participatory approaches and often seek to circumvent (rather than strengthen) weak public management structures. This limits opportunities for strengthening local health managers’ capacity, improving resource utilisation and enhancing service delivery. This study explored the contribution of a participatory action research approach to strengthening health managers’ capacity in Eastern Uganda. METHODS: This was a qualitative study that used open-ended key informant interviews, combined with review of meeting minutes and observations to collect data. Both inductive and deductive thematic analysis was undertaken. The Competing Values Framework of organisational management functions guided the deductive process of analysis and the interpretation of the findings. The framework builds on four earlier models of management and regards them as complementary rather than conflicting, and identifies four managers’ capacities (collaborate, create, compete and control) by categorising them along two axes, one contrasting flexibility versus control and the other internal versus external organisational focus. RESULTS: The findings indicate that the participatory action research approach enhanced health managers’ capacity to collaborate with others, be creative, attain goals and review progress. The enablers included expanded interaction spaces, encouragement of flexibility, empowerment of local managers, and the promotion of reflection and accountability. Tension and conflict across different management functions was apparent; for example, while there was a need to collaborate, maintaining control over processes was also needed. These tensions meant that managers needed to learn to simultaneously draw upon and use different capacities as reflected by the Competing Values Framework in order to maximise their effectiveness. CONCLUSIONS: Improved health manager capacity is essential if sustained improvements in health outcomes in lowincome countries are to be attained. The expansion of interaction spaces, encouragement of flexibility, empowerment of local managers, and the promotion of reflection and accountability were the key means by which participatory action research strengthened health managers’ capacity. The participatory approach to implementation therefore created opportunities to strengthen health managers’ capacity

Theorizing Institutional Scandal and the Regulatory State

One by one, UK public institutions are being scandalised for corruption, immorality or incompetence and subjected to trial by media and criminal prosecution. The state?s historic response to public sector scandal ? denial and neutralisation ? has been replaced with acknowledgement and regulation in the form of the re-vamped public inquiry. Public institutions are being cut adrift and left to account in isolation for their scandalous failures. Yet the state?s attempts to distance itself from its scandalised institutions, while extending its regulatory control over them, are risky. Both the regulatory state and its public inquiries risk being consumed by the scandal they are trying to manage

Leucine supplementation improves adiponectin and total cholesterol concentrations despite the lack of changes in adiposity or glucose homeostasis in rats previously exposed to a high-fat diet

<p>Abstract</p> <p>Background</p> <p>Studies suggest that leucine supplementation (LS) has a therapeutic potential to prevent obesity and to promote glucose homeostasis. Furthermore, regular physical exercise is a widely accepted strategy for body weight maintenance and also for the prevention of obesity. The aim of this study was to determine the effect of chronic LS alone or combined with endurance training (ET) as potential approaches for reversing the insulin resistance and obesity induced by a high-fat diet (HFD) in rats.</p> <p>Methods</p> <p>Forty-seven rats were randomly divided into two groups. Animals were fed a control diet-low fat (<it>n = </it>10) or HFD (<it>n = </it>37). After 15 weeks on HFD, all rats received the control diet-low fat and were randomly divided according to treatment: reference (REF), LS, ET, and LS+ET (<it>n = </it>7-8 rats per group). After 6 weeks of treatment, the animals were sacrificed and body composition, fat cell volume, and serum concentrations of total cholesterol, HDL-cholesterol, triacylglycerol, glucose, adiponectin, leptin and tumor necrosis factor-alpha (TNF-α) were analyzed.</p> <p>Results</p> <p>At the end of the sixth week of treatment, there was no significant difference in body weight between the REF, LS, ET and LS+ET groups. However, ET increased lean body mass in rats (<it>P </it>= 0.019). In addition, ET was more effective than LS in reducing adiposity (<it>P </it>= 0.019), serum insulin (<it>P </it>= 0.022) and TNF-α (<it>P </it>= 0.044). Conversely, LS increased serum adiponectin (<it>P </it>= 0.021) levels and reduced serum total cholesterol concentration (<it>P </it>= 0.042).</p> <p>Conclusions</p> <p>The results showed that LS had no beneficial effects on insulin sensitivity or adiposity in previously obese rats. On the other hand, LS was effective in increasing adiponectin levels and in reducing total cholesterol concentration.</p

Direct search for light gluinos

We present the results for a direct search for light gluinos through the appearance of eta -&gt; 3pi0 with high transverse momentum in the vacuum tank of the NA48 experiment at CERN. We find one event within a lifetime range of 10^-9 – 10^-3 s and another one between 10^-10 – 10^-9 s. Both events are consistent with the expected background from neutrons in the beam, produced by 450 GeV protons impinging on the Be targets, which interact with the residual air in the tank. From these data we give limits on the production of the hypothetical g gtilde bound state, the R0 hadron, and its R0 -&gt; eta gammatilde decay in the R0 mass range between 1 and 5 GeV