217 research outputs found

    Increase in circulating Foxp3+CD4+CD25high regulatory T cells in nasopharyngeal carcinoma patients

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    Nasopharyngeal carcinoma (NPC) is an Epstein–Barr virus-associated disease with high prevalence in Southern Chinese. Using multiparametric flow cytometry, we identified significant expansions of circulating naïve and memory CD4+CD25high T cells in 56 NPC patients compared with healthy age- and sex-matched controls. These were regulatory T cells (Treg), as they overexpressed Foxp3 and GITR, and demonstrated enhanced suppressive activities against autologous CD4+CD25− T-cell proliferation in functional studies on five patients. Abundant intraepithelial infiltrations of Treg with very high levels of Foxp3 expression and absence of CCR7 expression were also detected in five primary tumours. Our current study is the first to demonstrate an expansion of functional Treg in the circulation of NPC patients and the presence of infiltrating Treg in the tumour microenvironment. As Treg may play an important role in suppressing antitumour immunity, our findings provide critical insights for clinical management of NPC

    DC-electric-field-induced and low-frequency electromodulation second-harmonic generation spectroscopy of Si(001)-SiO2_2 interfaces

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    The mechanism of DC-Electric-Field-Induced Second-Harmonic (EFISH) generation at weakly nonlinear buried Si(001)-SiO2_2 interfaces is studied experimentally in planar Si(001)-SiO2_2-Cr MOS structures by optical second-harmonic generation (SHG) spectroscopy with a tunable Ti:sapphire femtosecond laser. The spectral dependence of the EFISH contribution near the direct two-photon E1E_1 transition of silicon is extracted. A systematic phenomenological model of the EFISH phenomenon, including a detailed description of the space charge region (SCR) at the semiconductor-dielectric interface in accumulation, depletion, and inversion regimes, has been developed. The influence of surface quantization effects, interface states, charge traps in the oxide layer, doping concentration and oxide thickness on nonlocal screening of the DC-electric field and on breaking of inversion symmetry in the SCR is considered. The model describes EFISH generation in the SCR using a Green function formalism which takes into account all retardation and absorption effects of the fundamental and second harmonic (SH) waves, optical interference between field-dependent and field-independent contributions to the SH field and multiple reflection interference in the SiO2_2 layer. Good agreement between the phenomenological model and our recent and new EFISH spectroscopic results is demonstrated. Finally, low-frequency electromodulated EFISH is demonstrated as a useful differential spectroscopic technique for studies of the Si-SiO2_2 interface in silicon-based MOS structures.Comment: 31 pages, 14 figures, 1 table, figures are also available at http://kali.ilc.msu.su/articles/50/efish.ht

    A review of the use of blood and blood products in HIV-infected patients

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    Despite numerous publications on the appropriate use of blood and blood products, few specifically consider the role of transfusion in the management of HIV. This review is a synthesis of conditions encountered in the management of HIV-infected patients where the transfusion of blood or blood products may be indicated. A consistent message emerging from the review is that the principles of transfusion medicine do not differ between HIV-negative and -positive patients. The aim of the review is to provide clinicians witha practical and succinct overview of the haematological abnormalities and clinical circumstances most commonly encountered in the HIV setting, while focusing on the rational and appropriate use of blood and blood products forHIV patients. Important ethical considerations in dealing with both the collection and transfusion blood and blood products in the HIV era have also been addressed

    Development of a compounded propofol nanoemulsion using multiple non-invasive process analytical technologies

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    Propofol is the preferred anaesthetic for induction and maintenance of sedation in critically ill mechanically ventilated COVID-19 patients. However, during the outbreak of the COVID-19 pandemic, regular supply chains could not keep up with the sudden increase in global demand, causing drug shortages. Propofol is formulated as an oil-in-water emulsion which is administered intravenously. This study explores the extemporaneous preparation of a propofol emulsion without specialized manufacturing equipment to temporally alleviate such shortages. A commercially available lipid emulsion (IVLE, SMOFlipid 20 %), intended for parenteral nutrition, was used to create a propofol loaded nanoemulsion via addition of liquid propofol drug substance and subsequent mixing. Critical quality attributes such as mean droplet size and the volume-weighted percentage of large-diameter (>5”m) droplets were studied. The evolution of droplet size and propofol distribution was monitored in situ and non-destructively, maintaining sterility, using Spatially Resolved Dynamic Light Scattering and Near Infrared Spectroscopy, respectively. Using response surface methodology, an optimum was found for a 4 % w/v propofol formulation with a ∌15 min mixing time in a flask shaker at a 40° shaking angle. This study shows that extemporaneous compounding is a viable option for emergency supply of propofol drug product during global drug shortages

    Targeted temperature management after cardiac arrest is associated with reduced metabolism of pantoprazole - a probe drug of CYP2C19 metabolism

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    OBJECTIVE\nMETHODS\nRESULTS\nCONCLUSION\nTargeted temperature management (TTM) is part of standard post-resuscitation care. TTM may downregulate cytochrome enzyme activity and thus impact drug metabolism. This study compared the pharmacokinetics (PK) of pantoprazole, a probe drug of CYP2C19-dependent metabolism, at different stages of TTM following cardiac arrest.\nThis prospective controlled study was performed at the Medical University of Vienna and enrolled 16 patients following cardiac arrest. The patients completed up to three study periods (each lasting 24 h) in which plasma concentrations of pantoprazole were quantified: (P1) hypothermia (33 °C) after admission, (P2) normothermia after rewarming (36 °C, intensive care), and (P3) normothermia during recovery (normal ward, control group). PK was analysed using non-compartmental analysis and nonlinear mixed-effects modelling.\n16 patients completed periods P1 and P2; ten completed P3. The median half-life of pantoprazole was 2.4 h (quartiles: 1.8-4.8 h) in P1, 2.8 h (2.1-6.8 h, p = 0.046 vs. P1, p = 0.005 vs. P3) in P2 and 1.2 h (0.9 - 2.3 h, p = 0.007 vs. P1) in P3. A two-compartment model described the PK data best. Typical values for clearance were estimated separately for each study period, indicating 40% and 29% reductions during P1 and P2, respectively, compared to P3. The central volume of distribution was estimated separately for P2, indicating a 64% increase compared to P1 and P3.\nCYP2C19-dependent drug metabolism is downregulated during TTM following cardiac arrest. These results may influence drug choice and dosing of similarly metabolized drugs and may be helpful for designing studies in similar clinical situations.Pharmacolog

    Individual Variations in Maternal Care Early in Life Correlate with Later Life Decision-Making and c-Fos Expression in Prefrontal Subregions of Rats

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    Early life adversity affects hypothalamus-pituitary-adrenal axis activity, alters cognitive functioning and in humans is thought to increase the vulnerability to psychopathology–e.g. depression, anxiety and schizophrenia- later in life. Here we investigated whether subtle natural variations among individual rat pups in the amount of maternal care received, i.e. differences in the amount of licking and grooming (LG), correlate with anxiety and prefrontal cortex-dependent behavior in young adulthood. Therefore, we examined the correlation between LG received during the first postnatal week and later behavior in the elevated plus maze and in decision-making processes using a rodent version of the Iowa Gambling Task (rIGT). In our cohort of male and female animals a high degree of LG correlated with less anxiety in the elevated plus maze and more advantageous choices during the last 10 trials of the rIGT. In tissue collected 2 hrs after completion of the task, the correlation between LG and c-fos expression (a marker of neuronal activity) was established in structures important for IGT performance. Negative correlations existed between rIGT performance and c-fos expression in the lateral orbitofrontal cortex, prelimbic cortex, infralimbic cortex and insular cortex. The insular cortex correlations between c-fos expression and decision-making performance depended on LG background; this was also true for the lateral orbitofrontal cortex in female rats. Dendritic complexity of insular or infralimbic pyramidal neurons did not or weakly correlate with LG background. We conclude that natural variations in maternal care received by pups may significantly contribute to later-life decision-making and activity of underlying brain structures

    Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

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    Introduction: Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and non-expert observers. Methods: For 132 consecutive patients with acute ischemic stroke, three experts and two trained observers determined thrombus density by placing three standardized regions of interest (ROIs) in the thrombus and corresponding contralateral arterial segment. Subsequently, absolute and relative thrombus densities were determined using either one or three ROIs. Intraclass correlation coefficient (ICC) was determined, and Bland–Altman analysis was performed to evaluate interobserver and intermethod agreement. Accuracy of the trained observer was evaluated with a reference expert observer using the same statistical analysis. Results: The highest interobserver agreement was obtained for absolute thrombus measurements using three ROIs (ICCs ranging from 0.54 to 0.91). In general, interobserver agreement was lower for relative measurements, and for using one instead of three ROIs. Interobserver agreement of trained non-experts and experts was similar. Accuracy of the trained observer measurements was comparable to the expert interobserver agreement and was better for absolute measurements and with three ROIs. The agreement between the one ROI and three ROI methods was good. Conclusion: Absolute thrombus density measurement has superior interobserver agreement compared to relative density measurement. Interobserver variation is smaller when multiple ROIs are used. Trained non-expert observers can accurately and reproducibly assess absolute thrombus densities using three ROIs

    Disruption of podocyte cytoskeletal biomechanics by dasatinib leads to nephrotoxicity

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    Nephrotoxicity is a critical adverse event that leads to discontinuation of kinase inhibitor (KI) treatment. Here we show, through meta-analyses of FDA Adverse Event Reporting System, that dasatinib is associated with high risk for glomerular toxicity that is uncoupled from hypertension, suggesting a direct link between dasatinib and podocytes. We further investigate the cellular effects of dasatinib and other comparable KIs with varying risks of nephrotoxicity. Dasatinib treated podocytes show significant changes in focal adhesions, actin cytoskeleton, and morphology that are not observed with other KIs. We use phosphoproteomics and kinome profiling to identify the molecular mechanisms of dasatinib-induced injury to the actin cytoskeleton, and atomic force microscopy to quantify impairment to cellular biomechanics. Furthermore, chronic administration of dasatinib in mice causes reversible glomerular dysfunction, loss of stress fibers, and foot process effacement. We conclude that dasatinib induces nephrotoxicity through altered podocyte actin cytoskeleton, leading to injurious cellular biomechanics.FWN – Publicaties zonder aanstelling Universiteit Leide

    Two-year clinical follow-up of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands (MR CLEAN): Design and statistical analysis plan of the extended follow-up study

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    Background: MR CLEAN was the first randomized trial to demonstrate the short-term clinical effectiveness of endovascular treatment in patients with acute ischemic stroke caused by large vessel occlusion in the anterior circulation. Several other trials confirmed that endovascular treatment improves clinical outcome at three months. However, limited data are available on long-term clinical outcome. We aimed to estimate the effect of endovascular treatment on functional outcome at two-year follow-up in patients with acute ischemic stroke. Secondly, we aimed to assess the effect of endovascular treatment on major vascular events and mortality during two years of follow-up. Methods: MR CLEAN is a multicenter clinical trial with randomized treatment allocation, open-label treatment, and blinded endpoint evaluation. Patients included were 18 years or older with acute ischemic stroke caused by a proven anterior proximal artery occlusion who could be treated within six hours after stroke onset. The intervention contrast was endovascular treatment and usual care versus no endovascular treatment and usual care. The current study extended the follow-up duration from three months to two years. The primary outcome is the score on the modified Rankin scale at two years. Secondary outcomes include all-cause mortality and the occurrence of major vascular events within two years of follow-up. Discussion: The results of our study provide information on the long-term clinical effectiveness of endovascular treatment, which may have implications for individual treatment decisions and estimates of cost-effectiveness. Trial registration:NTR1804. Registered on 7 May 2009; ISRCTN10888758. Registered on 24 July 2012 (main MR CLEAN trial); NTR5073. Registered on 26 February 2015 (extended follow-up study)
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