83 research outputs found

    Stationary IPA Estimates for Non-Smooth G/G/1/\infty Functionals via Palm Inversion and Level-Crossing Analysis

    Get PDF
    We give stationary estimates for the derivative of the expectation of a non-smooth function of bounded variation f of the workload in a G/G/1/\infty queue, with respect to a parameter influencing the distribu- tion of the input process. For this, we use an idea of Konstantopoulos and Zazanis based on the Palm inversion formula, however avoiding a limiting argument by performing the level-crossing analysis thereof globally, via Fubini's theorem. This method of proof allows to treat the case where the workload distribution has a mass at discontinuities of f and where the formula has to be modified. The case where the parameter is the speed of service or/and the time scale factor of the input process is also treated using the same approach

    Absence of association between pyronaridine in vitro responses and polymorphisms in genes involved in quinoline resistance in Plasmodium falciparum

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The aim of the present work was to assess the <it>in vitro </it>cross-resistance of pyronaridine with other quinoline drugs, artesunate and several other commonly used anti-malarials and to evaluate whether decreased susceptibility to pyronaridine could be associated with genetic polymorphisms in genes involved in reduced quinoline susceptibility, such as <it>pfcrt</it>, <it>pfmdr1</it>, <it>pfmrp </it>and <it>pfnhe</it>.</p> <p>Methods</p> <p>The <it>in vitro </it>chemosusceptibility profiles of 23 strains of <it>Plasmodium falciparum </it>were analysed by the standard 42-hour <sup>3</sup>H-hypoxanthine uptake inhibition method for pyronaridine, artesunate, chloroquine, monodesethylamodiaquine, quinine, mefloquine, lumefantrine, atovaquone, pyrimethamine and doxycycline. Genotypes were assessed for <it>pfcrt</it>, <it>pfmdr1</it>, <it>pfnhe-1 </it>and <it>pfmrp </it>genes.</p> <p>Results</p> <p>The IC<sub>50 </sub>values for pyronaridine ranged from 15 to 49 nM (geometric mean = 23.1 nM). A significant positive correlation was found between responses to pyronaridine and responses to artesunate (<it>r<sup>2 </sup></it>= 0.20; <it>P </it>= 0.0317) but too low to suggest cross-resistance. No significant correlation was found between pyronaridine IC<sub>50 </sub>and responses to other anti-malarials. Significant associations were not found between pyronaridine IC<sub>50 </sub>and polymorphisms in <it>pfcrt</it>, <it>pfmdr1</it>, <it>pfmrp </it>or <it>pfnhe-1</it>.</p> <p>Conclusion</p> <p>There was an absence of cross-resistance between pyronaridine and quinolines, and the IC<sub>50 </sub>values for pyronaridine were found to be unrelated to mutations in the transport protein genes <it>pfcrt</it>, <it>pfmdr1</it>, <it>pfmrp </it>or <it>pfnhe-1</it>, known to be involved in quinoline resistance. These results confirm the interest and the efficacy of the use of a combination of pyronaridine and artesunate in areas in which parasites are resistant to quinolines.</p

    The Involvement of SMILE/TMTC3 in Endoplasmic Reticulum Stress Response

    Get PDF
    The state of operational tolerance has been detected sporadically in some renal transplanted patients that stopped immunosuppressive drugs, demonstrating that allograft tolerance might exist in humans. Several years ago, a study by Brouard et al. identified a molecular signature of several genes that were significantly differentially expressed in the blood of such patients compared with patients with other clinical situations. The aim of the present study is to analyze the role of one of these molecules over-expressed in the blood of operationally tolerant patients, SMILE or TMTC3, a protein whose function is still unknown.We first confirmed that SMILE mRNA is differentially expressed in the blood of operationally tolerant patients with drug-free long term graft function compared to stable and rejecting patients. Using a yeast two-hybrid approach and a colocalization study by confocal microscopy we furthermore report an interaction of SMILE with PDIA3, a molecule resident in the endoplasmic reticulum (ER). In accordance with this observation, SMILE silencing in HeLa cells correlated with the modulation of several transcripts involved in proteolysis and a decrease in proteasome activity. Finally, SMILE silencing increased HeLa cell sensitivity to the proteasome inhibitor Bortezomib, a drug that induces ER stress via protein overload, and increased transcript expression of a stress response protein, XBP-1, in HeLa cells and keratinocytes.In this study we showed that SMILE is involved in the endoplasmic reticulum stress response, by modulating proteasome activity and XBP-1 transcript expression. This function of SMILE may influence immune cell behavior in the context of transplantation, and the analysis of endoplasmic reticulum stress in transplantation may reveal new pathways of regulation in long-term graft acceptance thereby increasing our understanding of tolerance

    HIV-1 Residual Viremia Correlates with Persistent T-Cell Activation in Poor Immunological Responders to Combination Antiretroviral Therapy

    Get PDF
    BACKGROUND:The clinical significance and cellular sources of residual human immunodeficiency virus type 1 (HIV-1) production despite suppressive combination antiretroviral therapy (cART) remain unclear and the effect of low-level viremia on T-cell homeostasis is still debated. METHODOLOGY/PRINCIPAL FINDINGS:We characterized the recently produced residual viruses in the plasma and short-lived blood monocytes of 23 patients with various immunological responses to sustained suppressive cART. We quantified the residual HIV-1 in the plasma below 50 copies/ml, and in the CD14(high) CD16(-) and CD16+ monocyte subsets sorted by flow cytometry, and predicted coreceptor usage by genotyping V3 env sequences. We detected residual viremia in the plasma of 8 of 10 patients with poor CD4+ T-cell reconstitution in response to cART and in only 5 of 13 patients with good CD4+ T-cell reconstitution. CXCR4-using viruses were frequent among the recently produced viruses in the plasma and in the main CD14(high) CD16(-) monocyte subset. Finally, the residual viremia was correlated with persistent CD4+ and CD8+ T-cell activation in patients with poor immune reconstitution. CONCLUSIONS:Low-level viremia could result from the release of archived viruses from cellular reservoirs and/or from ongoing virus replication in some patients. The compartmentalization of the viruses between the plasma and the blood monocytes suggests at least two origins of residual virus production during effective cART. CXCR4-using viruses might be produced preferentially in patients on cART. Our results also suggest that low-level HIV-1 production in some patients may contribute to persistent immune dysfunction despite cART

    WHEDA study: Effectiveness of occupational therapy at home for older people with dementia and their caregivers - the design of a pragmatic randomised controlled trial evaluating a Dutch programme in seven German centres

    Get PDF
    Contains fulltext : 80941.pdf (publisher's version ) (Open Access)BACKGROUND: A recent Dutch mono-centre randomised controlled trial has shown that occupational therapy improves daily functioning in dementia. The aim of this present study is to compare the effects of the Dutch community occupational therapy programme with a community occupational therapy consultation on daily functioning in older people with mild or moderate dementia and their primary caregivers in a German multi-centre context. METHODS/DESIGN: A multi-centre single blind randomised controlled trial design is being used in seven health care centres (neurological, psychiatric and for older people) in urban regions. Patients are 1:1 randomised to treatment or control group. Assessors are blind to group assignment and perform measurements on both groups at baseline, directly after intervention at 6 weeks and at 16, 26 and 52 weeks follow-up. A sample of 140 community dwelling older people (aged >65 years) with mild or moderate dementia and their primary caregivers is planned. The experimental intervention consists of an evidence-based community occupational therapy programme including 10 sessions occupational therapy at home. The control intervention consists of one community occupational therapy consultation based on information material of the Alzheimer Society. Providers of both interventions are occupational therapists experienced in treatment of cognitively impaired older people and trained in both programmes. 'Community' indicates that occupational therapy intervention occurs in the person's own home. The primary outcome is patients' daily functioning assessed with the performance scale of the Interview for Deterioration in Daily Living Activities in Dementia and video tapes of daily activities rated by external raters blind to group assignment using the Perceive, Recall, Plan and Perform System of Task Analysis. Secondary outcomes are patients' and caregivers' quality of life, mood and satisfaction with treatment; the caregiver's sense of competence, caregiver's diary (medication, resource utilisation, time of informal care); and the incidence of long-term institutionalisation. Process evaluation is performed by questionnaires and focus group discussion. DISCUSSION: The transfer from the Dutch mono-centre design to the pragmatic multi-site trial in a German context implicates several changes in design issues including differences in recruitment time, training of interventionists and active control group treatment.The study is registered under DRKS00000053 at the German register of clinical trials, which is connected to the International Clinical Trials Registry Platform

    Clinical Pharmacokinetics and Pharmacodynamics of Dexmedetomidine

    Get PDF
    corecore