Metabolic responses to in vitro zinc supplementation

The present study was carried out to determine the effects and possible mechanism of action of zinc supplementation on the in vitro growth of malignant murine melanoma (B16) and non-malignant monkey kidney (LLCMK) cells. Cell culture studies showed that zinc supplementation significantly inhibited B16 growth at all the concentrations studied (1, 3, 5 and lOμg/ml). Zinc was also found to inhibit the growth of the LLCMK cells, although to a lesser extent than the B16 cells. Possible evidence of mobilisation of the essential fatty acids from the membrane phospholipid stores was noted in both cell types. This effect was, however, greater in the B16 cells. Δ⁶-desaturase activity was found to be significantly lower in the B16 cells than in the LLCMK cells (p ≥ 0.05). Zinc supplementation resulted in an increase in the enzymes activity in the LLCMK cells and, at high concentrations, in the B16 cells. An estimation of elongase and Δ⁶-desaturase activity with zinc supplementation indicated that zinc had little or no effect on the activity of these enzymes. B16 cells were found to have higher levels of free radicals than the LLCMK cells. Zinc supplementation resulted in increased free radical formation in the B16 cells, while no effect was observed in the LLCMK cells. Lipid peroxidation increased in both cell types with increased zinc concentrations. The observed effect of zinc supplementation on cell growth may involve these elevated levels of lipid peroxides. CycIo-oxygenase activity was found to be greater in the B16 cells than the LLCMK cells. The activity of the enzyme increased with higher concentrations of zinc (lOμg/ml) in both cell types. Prostaglandin E, levels were found to be lower in the B16 cells compared to the LLCMK cells. The levels of prostaglandin E, in both cell types appeared to be dependent on the levels of the polyunsaturated fatty acid precursors to the prostaglandins. Zinc was found to inhibit the activity of the enzyme adenylate cyclase in both cell types. The cAMP levels in the LLCMK cells were also found to decrease with zinc supplementation. In the case of the B16 cells, cAMP levels increased at low concentrations of zinc despite a decrease in adenyl ate cyclase activity, suggesting a possible inhibition of cAMP phosphodiesterase activity at these concentrations of zinc. It is concluded that although zinc supplementation does have an effect on cell growth, this effect is not mediated through the activation of adenylate cyclase by the prostaglandins resulting in elevated levels of cAMP. A possible mechanism involving lipid peroxidation is proposed

Moving in 3D: the X, Y, Z of learning through doing in immersive, virtual environments

In this paper, we review past empirical research studies on the use of tactile precision in three dimensional immersive learning environments. A number of questions guided our review 1) What is the potential for tactile precision in 3D multimodal environments (drawing on literature from range of disciplines including IT, gaming, engineering, health sciences and education); 2) How is this being imagined and explored for education-related purposes in different disciplines; 4) How have learners responded to the potential for more tactile/kinaesthetic learning and 5) What are the gaps in the research

A quest for the holy grail: Tactile precision, natural movement and haptic feedback in 3D virtual spaces

Three-dimensional immersive spaces such as those provided by virtual worlds, give unparalleled opportunities for learners to practically engage with simulated authentic settings that may be too expensive or too dangerous to experience in the real world. The potential afforded by these environments is severely constrained by the use of a keyboard and mouse moving in two dimensions. While most technologies have evolved rapidly in the early 21st century, the mouse and keyboard as standard navigation and interaction tools have not. However, talented teams from a range of disciplines are on serious quests to address this limitation. Their Holy Grail is to develop ways to interact with 3D immersive spaces using more natural human movements with haptic feedback. Applications would include the training of surgeons and musical conductors, training elite sports people and even physical rehabilitation. This paper reports on the cutting-edge technology projects that look most likely to provide a solution for this complex problem, including the Wiimote and the Microsoft's Project Natal. © 2009 Helen Farley and Caroline Steel

Pharmacological control of neutrophil-mediated inflammation: Strategies targeting calcium handling by activated polymorphonuclear leukocytes

Unlike most other effector cells of the innate, as well as the adaptive immune systems, the neutrophil is a relatively undiscerning aggressor with scant regard for damage limitation. Although this highly combative, professional phagocyte has become increasingly implicated in the immunopathogenesis of many acute and chronic inflammatory disorders, of both infective and noninfective origin, effective pharmacological strategies to counter neutrophilaggression have remained elusive. Activation of neutrophils results in rapid mobilization of both stored and extracellular Ca2+, resulting in abrupt, usually transient increases in cytosolic Ca2+, which precede, and are a prerequisite for activation of the Ca2+-dependent pro-inflammatory activities of these cells. Mobilization of Ca2+ by, and restoration of Ca2+ homeostasis to activated neutrophils are multistep processes which present a number of potential targets, some well recognized and others noveland unconventional, for the pharmacological control of neutrophil-mediated inflammation. Uncovering these targets represents the primary focus of this review

Opportunities for intra-university collaborations in the new research environment

New opportunities for research collaborations within universities are explored through reflection on a recent collaboration between an academic researcher, the library and the eResearch Centre at a regional Australian university. Such opportunities arise from significant changes to the research landscape, including increased emphasis on open access publication of research outputs and the growth of eResearch capabilities. The latter has resulted in increases in data size and complexity and provides opportunities for collaboration across research institutions. This article reflects on the dynamics and assesses the outcomes of a collaboration formed during an externally funded open research data project. This project and a precursor project are briefly described, together with the specific contribution of each collaborator. Collaboration dynamics and the reasons for project success are assessed, as are implications for future research practice. Outcomes from eResearch collaborations may provide broader benefits to universities, as well as rewards to academic researchers

Protein kinase C promotes restoration of calcium homeostasis to platelet activating factor-stimulated human neutrophils by inhibition of phospholipase C

<p>Abstract</p> <p>Background</p> <p>The role of protein kinase C (PKC) in regulating the activity of phospholipase C (PLC) in neutrophils activated with the chemoattractant, platelet-activating factor (PAF, 20 and 200 nM), was probed in the current study using the selective PKC inhibitors, GF10903X (0.5 - 1 μM) and staurosporine (400 nM).</p> <p>Methods</p> <p>Alterations in cytosolic Ca²⁺, Ca²⁺influx, inositol triphosphate (IP₃), and leukotriene B₄production were measured using spectrofluorimetric, radiometric and competitive binding radioreceptor and immunoassay procedures, respectively.</p> <p>Results</p> <p>Activation of the cells with PAF was accompanied by an abrupt increase in cytosolic Ca²⁺followed by a gradual decline towards basal levels. Pretreatment of neutrophils with the PKC inhibitors significantly increased IP₃production with associated enhanced Ca²⁺release from storage vesicles, prolongation of the peak cytosolic Ca²⁺transients, delayed clearance and exaggerated reuptake of the cation, and markedly increased synthesis of LTB₄. The alterations in Ca²⁺fluxes observed with the PKC inhibitors were significantly attenuated by U73122, a PLC inhibitor, as well as by cyclic AMP-mediated upregulation of the Ca²⁺-resequestering endomembrane ATPase.</p> <p>Taken together, these observations are compatible with a mechanism whereby PKC negatively modulates the activity of PLC, with consequent suppression of IP₃production and down-regulation of Ca²⁺mediated pro-inflammatory responses of PAF-activated neutrophils.</p> <p>Conclusion</p> <p>Although generally considered to initiate and/or amplify intracellular signalling cascades which activate and sustain the pro-inflammatory activities of neutrophils and other cell types, the findings of the current study have identified a potentially important physiological, anti-inflammatory function for PKC, at least in neutrophils.</p

Overview of community-acquired pneumonia and the role of imflammatory mechanisms in the immunopathogenesis of severe pneumococcal disease

Community-acquired pneumonia (CAP) remains a leading cause of morbidity and mortality among the infectious diseases.Despite the implementation of national pneumococcal polyvalent vaccine-based immunisation strategies targeted at high-risk groups, Streptococcus pneumoniae (the pneumococcus) remains the most common cause of CAP. Notwithstanding the HIV pandemic, major challenges confronting the control of CAP include the range of bacterial and viral pathogens causing this condition, the ever-increasing problem of antibiotic resistance worldwide, and increased vulnerability associated with steadily aging populations in developed countries.These and other risk factors, as well as diagnostic strategies, are covered in the first section of this review. Thereafter, the review is focused on the pneumococcus, specifically the major virulence factors of this microbial pathogen and their role in triggering overexuberant inflammatory responses which contribute to the immunopathogenesis of invasive disease. The final section of the review is devoted to a consideration of pharmacological, anti-inflammatory strategies with adjunctive potential in the antimicrobial chemotherapy of CAP. This is focused on macrolides, corticosteroids, and statins with respect to their modes of anti-inflammatory action, current status, and limitations.http://www.hindawi.comam201

Constituting a public umbilical cord blood bank in South Africa

No abstract availableThe South African Medical Research Council of in terms of the MRC’s Flagships Awards Project SAMRC-RFA-UFSP-01-2013/STEM CELLS, the Institute for Cellular and Molecular Medicine of the University of Pretoria, and the National Research Foundation of South Africa.http://www.nature.com/bmt2015-09-30hb201