38 research outputs found

    The orally administered P-glycoprotein inhibitor R101933 does not alter the plasma pharmacokinetics of docetaxel

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    This Phase I study was performed to assess the feasibility of combining docetaxel with the new P-glycoprotein inhibitor R101933 and to determine the dose limiting toxicity of this combination. Fifteen patients received oral R101933 alone at a dose escalated from 200 to 300 mg twice daily (b.i.d.; cycle 0), an escalating i.v. dose of docetaxel (60, 75, and 100 mg/m2) as a 1-h infusion (cycle 1), and the combination (cycle 2 and further). Dose limiting toxicity consisting of mucositis and neutropenic fever was reached at the combination of docetaxel, 100 mg/m2, and R101933, 300 mg b.i.d., and the maximum tolerated dose was established at docetaxel, 100 mg/m2, and R101933, 200 mg b.i.d. Plasma concentrations of R101933 achieved in patients were in the same range as required in preclinical rodent models to overcome paclitaxel resistance. The plasma pharmacokinetics of docetaxel were not influenced by the R101933 regimen at any dose level tested, as indicated by plasma clearance values of 26.5 +/- 7.78 liters/h/m2 and 23.4 +/- 4.52 liters/h/m2 (P = 0.15) in cycles 1 and 2, respectively. These findings indicate that the contribution of a P-glycoprotein inhibitor to the activity of anticancer chemotherapy can now be assessed in patients for the first time independent of its effect on drug pharmacokinetics

    Toward harmonized phenotyping of human myeloid-derived suppressor cells by flow cytometry: results from an interim study

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    There is an increasing interest for monitoring circulating myeloid-derived suppressor cells (MDSCs) in cancer patients, but there are also divergences in their phenotypic definition. To overcome this obstacle, the Cancer Immunoguiding Program under the umbrella of the Association of Cancer Immunotherapy is coordinating a proficiency panel program that aims at harmonizing MDSC phenotyping. After a consultation period, a two-stage approach was designed to harmonize MDSC phenotype. In the first step, an international consortium of 23 laboratories immunophenotyped 10 putative MDSC subsets on pretested, peripheral blood mononuclear cells of healthy donors to assess the level of concordance and define robust marker combinations for the identification of circulating MDSCs. At this stage, no mandatory requirements to standardize reagents or protocols were introduced. Data analysis revealed a small intra-laboratory, but very high inter-laboratory variance for all MDSC subsets, especially for the granulocytic subsets. In particular, the use of a dead-cell marker altered significantly the reported percentage of granulocytic MDSCs, confirming that these cells are especially sensitive to cryopreservation and/or thawing. Importantly, the gating strategy was heterogeneous and associated with high inter-center variance. Overall, our results document the high variability in MDSC phenotyping in the multicenter setting if no harmonization/standardization measures are applied. Although the observed variability depended on a number of identified parameters, the main parameter associated with variation was the gating strategy. Based on these findings, we propose further efforts to harmonize marker combinations and gating parameters to identify strategies for a robust enumeration of MDSC subsets

    A comparison of clinical pharmacodynamics of different administration schedules of oral topotecan (Hycamtin)

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    Prolonged exposure to topotecan in in vitro and in vivo experiments has yielded the highest antitumor efficacy. An oral formulation of topotecan with a bioavailability of 32-44% in humans enables convenient prolonged administration. Pharmacokinetic/pharmacodynamic relationships from four Phase I studies with different schedules of administration of oral topotecan in 99 adult patients with malignant solid tumors refractory to standard forms of chemotherapy were compared. Topotecan was administered as follows: (a) once daily (o.d.) for 5 days every 21 days (29 patients); (b) o.d. for 10 days every 21 days (19 patients); (c) twice daily (b.i.d.) for 10 days every 21 days (20 patients); and (d) b.i.d. for 21 days every 28 days (31 patients). Pharmacokinetic analysis was performed in 55 patients using a validated high-performance liquid chromatographic assay and noncompartmental pharmacokinetic me

    Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

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    Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

    Hide and seek: Directing top-down attention is not sufficient for accelerating conscious access

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    At any moment in time, we have a single conscious visual experience representing a minute part of our visual world. As such, the visual input stimulating our retinae is in continuous competition for reaching conscious access. Many complex cognitive operations can only be applied to consciously accessible visual information, thereby raising the question whether humans have the ability to select which parts of their visual input rea- ches consciousness. Top-down attention allows humans to flexibly assign more processing resources to certain parts of our visual input, making it a likely mechanism to volitionally bias conscious access. Here, we investigated whether directing top-down attention to a particular location or feature accelerates conscious access of an initially suppressed visual stimulus at the attended location, or of the attended feature. We instructed participants to attend a spatial location (Experiment 1) or color (Experiment 2) for a speeded discrimination task, using a highly predictive cue. The predictive cues were highly effective in prompting sustained attention towards the cued location or color, as evidenced by faster discrimination of cued relative to uncued targets. We simultaneously measured detection times to interocularly suppressed probes that were either of the cued (i.e., attended) color/location or not, and were visually distinct from the targets used for the discrimination task. Despite our successful manipulation of top-down attention, suppressed probes were not released from suppression faster when they were presented at the attended location, or in the attended color. In contrast, when observers were cued to attend a color for locating targets of an ill-defined shape (inciting a broader attentional template), we did observe faster conscious access of probes in the attended color (Experiment 3). We discuss our findings in light of the specificity of attentional templates, and the inherent limitations that this poses for top-down attentional biases on conscious access

    Hide and seek: Directing top-down attention is not sufficient for accelerating conscious access

    No full text
    At any moment in time, we have a single conscious visual experience representing a minute part of our visual world. As such, the visual input stimulating our retinae is in continuous competition for reaching conscious access. Many complex cognitive operations can only be applied to consciously accessible visual information, thereby raising the question whether humans have the ability to select which parts of their visual input rea- ches consciousness. Top-down attention allows humans to flexibly assign more processing resources to certain parts of our visual input, making it a likely mechanism to volitionally bias conscious access. Here, we investigated whether directing top-down attention to a particular location or feature accelerates conscious access of an initially suppressed visual stimulus at the attended location, or of the attended feature. We instructed participants to attend a spatial location (Experiment 1) or color (Experiment 2) for a speeded discrimination task, using a highly predictive cue. The predictive cues were highly effective in prompting sustained attention towards the cued location or color, as evidenced by faster discrimination of cued relative to uncued targets. We simultaneously measured detection times to interocularly suppressed probes that were either of the cued (i.e., attended) color/location or not, and were visually distinct from the targets used for the discrimination task. Despite our successful manipulation of top-down attention, suppressed probes were not released from suppression faster when they were presented at the attended location, or in the attended color. In contrast, when observers were cued to attend a color for locating targets of an ill-defined shape (inciting a broader attentional template), we did observe faster conscious access of probes in the attended color (Experiment 3). We discuss our findings in light of the specificity of attentional templates, and the inherent limitations that this poses for top-down attentional biases on conscious access

    Objective Portrait: A practice-based inquiry to explore Al as a reflective design partner

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    Artificial intelligence (AI) is increasingly being viewed as a creative partner rather than as a tool. How to design such collaborations is still a subject of speculation. In this pictorial, we propose a collaborative role for AI to prompt self-reflection. We explore this through a practice-based inquiry of whether and how AI could help a designer reflect on and relate to their own work. Three designers annotate a collection of images representing their fascinations, with subjective labels, indicating different dimensions of their visual concepts. These labels are used to teach an object detection model the designers’ perspectives. Then, they used this trained model on their own design work to evaluate the AI's potential to prompt self-reflection. By describing this process of AI-training we explore how an AI can help us become aware of our own implicit perspectives.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Methodologie en Organisatie van Desig

    Efficacy of adalimumab in sarcoidosis patients who developed intolerance to infliximab

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    BACKGROUND: Tumor necrosis factor-alpha (TNF-α) inhibitors are regarded as the third-line therapy in sarcoidosis, the first choice generally being infliximab. To date, data regarding response to adalimumab in sarcoidosis patients intolerant to infliximab are lacking. The objective of this retrospective observational study was to establish if adalimumab could achieve stabilization or improvement of the disease in refractory sarcoidosis patients who developed intolerance to infliximab. MATERIAL AND METHODS: Sarcoidosis patients referred to St Antonius Interstitial Lung Diseases Center of Excellence, Nieuwegein, The Netherlands, between January 2008 and April 2015 who switched from infliximab to adalimumab were included. Changes in organ function, inflammatory biomarker levels, and adverse events were retrieved from medical records. RESULTS: Out of 142 infliximab treated patients, 18 (13%) had to discontinue treatment due to antibody formation or severe adverse events and switched to adalimumab therapy. Organ function improved in 7 patients (39%), was stable in 6 patients (33%), and worsened in 5 patients (28%) after 12 months of treatment or after 6 months if evaluation after 12 months was not available (n = 4). In none of the patients biomarker levels of soluble interleukin-2 receptor (sIL-2R) deteriorated. Median decrease in sIL-2R was 3614 pg/mL. Most reported adverse event was infection (n = 10). CONCLUSIONS: Adalimumab is an effective alternative for patients intolerant to infliximab. The switch to adalimumab achieved clinical improvement in 39% and stabilization in 33% of patients intolerant to infliximab. Further research is needed to develop guidelines on how to use adalimumab for sarcoidosis in terms of dosing regimen
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