127 research outputs found

    A qualitative study of the views of patients with long-term conditions on family doctors in Hong Kong

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    <b>Background</b> Primary care based management of long-term conditions (LTCs) is high on the international healthcare agenda, including the Asia-Pacific region. Hong Kong has a 'mixed economy' healthcare system with both public and private sectors with a range of types of primary care doctors. Recent Hong Kong Government policy aims to enhance the management of LTCs in primary care possibly based on a 'family doctor' model. Patients' views on this are not well documented and the aim of the present study was to explore the views of patients with LTCs on family doctors in Hong Kong.<p></p> <b>Methods</b> The views of patients (with a variety of LTCs) on family doctors in Hong Kong were explored. Two groups of participants were interviewed; a) those who considered themselves as having a family doctor, b) those who considered themselves as not having a family doctor (either with a regular primary care doctor but not a family doctor or with no regular primary care doctor). In-depth individual semi-structured interviews were carried out with 28 participants (10 with a family doctor, 10 with a regular doctor, and 8 with no regular doctor) and analysed using the constant comparative method.<p></p> <b>Results</b> Participants who did not have a family doctor were familiar with the concept but regarded it as a 'luxury item' for the rich within the private healthcare system. Those with a regular family doctor (all private) regarded having one as important to their and their family's health. Participants in both groups felt that as well as the more usual family medicine specialist or general practitioner, traditional Chinese medicine practitioners also had the potential to be family doctors. However most participants attended the public healthcare system for management of their LTCs whether they had a family doctor or not. Cost, perceived need, quality, trust, and choice were all barriers to the use of family doctors for the management of their LTCs.<p></p> <b>Conclusions</b> Important barriers to the adoption of a 'family doctor' model of management of LTCs exist in Hong Kong. Effective policy implementation seems unlikely unless these complex barriers are addressed

    Differential Adhesive Properties of Sequestered Asexual and Sexual Stages of Plasmodium falciparum on Human Endothelial Cells Are Tissue Independent

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    The protozoan parasite Plasmodium falciparum, responsible for the most severe form of malaria, is able to sequester from peripheral circulation during infection. The asexual stage parasites sequester by binding to endothelial cell receptors in the microvasculature of various organs. P. falciparum gametocytes, the developmental stages responsible for parasite transmission from humans to Anopheles mosquitoes, also spend the almost ten days necessary for their maturation sequestered away from the peripheral circulation before they are released in blood mainstream. In contrast to those of asexual parasites, the mechanisms and cellular interactions responsible for immature gametocyte sequestration are largely unexplored, and controversial evidence has been produced so far on this matter. Here we present a systematic comparison of cell binding properties of asexual stages and immature and mature gametocytes from the reference P. falciparum clone 3D7 and from a patient parasite isolate on a panel of human endothelial cells from different tissues. This analysis includes assays on human bone marrow derived endothelial cell lines (HBMEC), as this tissue has been proposed as a major site of gametocyte maturation. Our results clearly demonstrate that cell adhesion of asexual stage parasites is consistently more efficient than that, virtually undetectable of immature gametocytes, irrespectively of the endothelial cell lines used and of parasite genotypes. Importantly, immature gametocytes of both lines tested here do not show a higher binding efficiency compared to asexual stages on bone marrow derived endothelial cells, unlike previously reported in the only study on this issue. This indicates that gametocyte-host interactions in this tissue are unlikely to be mediated by the same adhesion processes to specific endothelial receptors as seen with asexual forms

    GM-CSF Signalling Boosts Dramatically IL-1Production

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    GM-CSF is mostly known for its capacity to promote bone marrow progenitor differentiation, to mobilize and mature myeloid cells as well as to enhance host immune responses. However the molecular actions of GM-CSF are still poorly characterized. Here we describe a new surprising facet of this “old” growth factor as a key regulator involved in IL-1βsecretion. We found that IL-1β release, a pivotal component of the triggered innate system, is heavily dependent on the signaling induced by GM-CSF in such an extent that in its absence IL-1β is only weakly secreted. GM-CSF synergizes with LPS for IL-1β secretion mainly at the level of pro-IL-1β production via strengthening the NF-κB signaling. In addition, we show that expression of Rab39a, a GTPase required for caspase-1 dependent IL-1β secretion is greatly augmented by LPS and GM-CSF co-stimulation suggesting a potential GM-CSF contribution in enhancing IL-1β exocytosis. The role of GM-CSF in regulating IL-1β secretion is extended also in vivo, since GM-CSF R−/− mice are more resistant to LPS-mediated septic shock. These results identify GM-CSF as a key regulator of IL-1β production and indicate GM-CSF as a previously underestimated target for therapeutic intervention

    STAT3 Is Activated by JAK2 Independent of Key Oncogenic Driver Mutations in Non-Small Cell Lung Carcinoma

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    Constitutive activation of STAT3 is a common feature in many solid tumors including non-small cell lung carcinoma (NSCLC). While activation of STAT3 is commonly achieved by somatic mutations to JAK2 in hematologic malignancies, similar mutations are not often found in solid tumors. Previous work has instead suggested that STAT3 activation in solid tumors is more commonly induced by hyperactive growth factor receptors or autocrine cytokine signaling. The interplay between STAT3 activation and other well-characterized oncogenic “driver” mutations in NSCLC has not been fully characterized, though constitutive STAT3 activation has been proposed to play an important role in resistance to various small-molecule therapies that target these oncogenes. In this study we demonstrate that STAT3 is constitutively activated in human NSCLC samples and in a variety of NSCLC lines independent of activating KRAS or tyrosine kinase mutations. We further show that genetic or pharmacologic inhibition of the gp130/JAK2 signaling pathway disrupts activation of STAT3. Interestingly, treatment of NSCLC cells with the JAK1/2 inhibitor ruxolitinib has no effect on cell proliferation and viability in two-dimensional culture, but inhibits growth in soft agar and xenograft assays. These data demonstrate that JAK2/STAT3 signaling operates independent of known driver mutations in NSCLC and plays critical roles in tumor cell behavior that may not be effectively inhibited by drugs that selectively target these driver mutations

    Regulation of Toll-like receptor signaling by NDP52-mediated selective autophagy is normally inactivated by A20

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    Toll-like receptor (TLR) signaling is linked to autophagy that facilitates elimination of intracellular pathogens. However, it is largely unknown whether autophagy controls TLR signaling. Here, we report that poly(I:C) stimulation induces selective autophagic degradation of the TLR adaptor molecule TRIF and the signaling molecule TRAF6, which is revealed by gene silencing of the ubiquitin-editing enzyme A20. This type of autophagy induced formation of autophagosomes and could be suppressed by an autophagy inhibitor and lysosomal inhibitors. However, this autophagy was not associated with canonical autophagic processes, including involvement of Beclin-1 and conversion of LC3-I to LC3-II. Through screening of TRIF-interacting ‘autophagy receptors’ in human cells, we identified that NDP52 mediated the selective autophagic degradation of TRIF and TRAF6 but not TRAF3. NDP52 was polyubiquitinated by TRAF6 and was involved in aggregation of TRAF6, which may result in the selective degradation. Intriguingly, only under the condition of A20 silencing, NDP52 could effectively suppress poly(I:C)-induced proinflammatory gene expression. Thus, this study clarifies a selective autophagic mechanism mediated by NDP52 that works downstream of TRIF–TRAF6. Furthermore, although A20 is known as a signaling fine-tuner to prevent excess TLR signaling, it paradoxically downregulates the fine-tuning effect of NDP52 on TLR signaling

    Tumor Associated Macrophages Protect Colon Cancer Cells from TRAIL-Induced Apoptosis through IL-1β- Dependent Stabilization of Snail in Tumor Cells

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    We recently reported that colon tumor cells stimulate macrophages to release IL-1beta, which in turn inactivates GSK3beta and enhances Wnt signaling in colon cancer cells, generating a self-amplifying loop that promotes the growth of tumor cells.Here we describe that macrophages protect HCT116 and Hke-3 colon cancer cells from TRAIL-induced apoptosis. Inactivation of IL-1beta by neutralizing IL-1beta antibody, or silencing of IL-1beta in macrophages inhibited their ability to counter TRAIL-induced apoptosis. Accordingly, IL-1beta was sufficient to inhibit TRAIL-induced apoptosis. TRAIL-induced collapse of the mitochondrial membrane potential (Delta psi) and activation of caspases were prevented by macrophages or by recombinant IL-1beta. Pharmacological inhibition of IL-1beta release from macrophages by vitamin D(3), a potent chemopreventive agent for colorectal cancer, restored the ability of TRAIL to induce apoptosis of tumor cells cultured with macrophages. Macrophages and IL-1beta failed to inhibit TRAIL-induced apoptosis in HCT116 cells expressing dnIkappaB, dnAKT or dnTCF4, confirming that they oppose TRAIL-induced cell death through induction of Wnt signaling in tumor cells. We showed that macrophages and IL-1beta stabilized Snail in tumor cells in an NF-kappaB/Wnt dependent manner and that Snail deficient tumor cells were not protected from TRAIL-induced apoptosis by macrophages or by IL-1beta, demonstrating a crucial role of Snail in the resistance of tumor cells to TRAIL.We have identified a positive feedback loop between tumor cells and macrophages that propagates the growth and promotes the survival of colon cancer cells: tumor cells stimulate macrophages to secrete IL-1beta, which in turn, promotes Wnt signaling and stabilizes Snail in tumor cells, conferring resistance to TRAIL. Vitamin D(3) halts this amplifying loop by interfering with the release of IL-1beta from macrophages. Accordingly, vitamin D(3) sensitizes tumor cells to TRAIL-induced apoptosis, suggesting that the therapeutic efficacy of TRAIL could be augmented by this readily available chemopreventive agent

    Prevention of bone metastases and management of bone health in early breast cancer

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    Treatment options for women with early-stage breast cancer have never been better, and the addition of bisphosphonates to adjuvant therapy is a valuable new tool capable of substantially improving clinical outcomes for these women. Several recent studies demonstrated that the anticancer activity of bisphosphonates is not limited to bone, and can translate into a reduction in disease recurrence, including reductions in locoregional and distant metastases. In addition, bisphosphonates maintain bone health during adjuvant therapy; this may be especially important for women who are at high risk for fracture
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