595 research outputs found

    Pressure-Corrected Carotid Stiffness and Young's Modulus: Evaluation in an Outpatient Clinic Setting

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    Background: Conventional measures for assessing arterial stiffness are inherently pressure dependent. Whereas statistical pressure adjustment is feasible in (larger) populations, it is unsuited for the evaluation of an individual patient. Moreover, statistical "correction"for blood pressure may actually correct for: (i) the acute dependence of arterial stiffness on blood pressure at the time of measurement; and/or (ii) the remodeling effect that blood pressure (hypertension) may have on arterial stiffness, but it cannot distinguish between these processes. METHODS: We derived - assuming a single-exponential pressure-diameter relationship - 3 theoretically pressure-independent carotid stiffness measures suited for individual patient evaluation: (i) stiffness index β0, (ii) pressure-corrected carotid pulse wave velocity (cPWVcorr), and (iii) pressure-corrected Young's modulus (Ecorr). Using linear regression analysis, we evaluated in a sample of the CATOD study cohort changes in mean arterial pressure (ΔMAP) and comparatively the changes in the novel (Δβ0, ΔcPWVcorr, and ΔEcorr) as well as conventional (ΔcPWV and ΔE) stiffness measures after a 2.9 ± 1.0-year follow-up. RESULTS: We found no association between ΔMAP and Δβ0, ΔcPWVcorr, or ΔEcorr. In contrast, we did find a significant association between ΔMAP and conventional measures ΔcPWV and ΔE. Additional adjustments for biomechanical confounders and traditional risk factors did neither materially change these associations nor the lack thereof. Conclusions: Our newly proposed pressure-independent carotid stiffness measures avoid the need for statistical correction. Hence, these measures (β0, cPWVcorr, and Ecorr) can be used in a clinical setting for (i) patient-specific risk assessment and (ii) investigation of potential remodeling effects of (changes in) blood pressure on intrinsic arterial stiffness

    A new process for the recovery of ammonia from ammoniated high-salinity brine

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    This paper describes a new method for the recovery of high-concentration ammonia from water in the form of ammonium chloride, ammonium hydroxide and ammonium carbonate. The method was applied to the Solvay process, in which sodium bicarbonate is produced through the reaction of ammoniated brine and CO2 gas. The Solvay effluent contains ammonia in the form of soluble ammonium chloride. The proposed method is based on the recovery of ammonia using a high-alkalinity reactant, calcium oxide (CaO), in a closed electrocoagulation cell operating at a specific current density. The recovered ammonia is collected as a gas within a closed cell containing deionized (DI) water at room temperature. Afterwards, the collected solution (DI water-NH3 gas) is concentrated through a separate process, and is then reused in the Solvay process and other applications. The electrocoagulation process is applied to the treatment cell using aluminum electrodes and a current density of 5-15 mA/cm2 . After 7 h of treatment using the electrocoagulation cell, a high reduction of the ammonia concentration-99%-was realized after ~9 h of the electrochemical treatment. The initial ammonia concentration in a Solvay effluent of 13,700 mg/L N was decreased to 190 mg/L N. Furthermore, an ammonia recovery of 77.1% in the form of ammonium hydroxide was achieved. Generally, this process, which starts at room temperature, can result in an energy reduction of 80%-from 7.8 to 2.3 kWh/kg NH3-compared to conventional processes, which entail heating the Solvay effluents to 160?C. The proposed system and method were found to be suitable for the recovery of ammonia from ammoniated water, and can be utilized for the treatment of landfill leachate, and municipal and industrial wastewater.Funding: This research was funded by United Arab Emirates University, grant number G00002622.Scopu

    The effect of taurolidine on the time-to-positivity of blood cultures

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    Background: Taurolidine containing lock solutions (TL) are a promising method for the prevention of central line associated bloodstream infections. Per accident, the TL may not always be aspirated from the central venous catheter (CVC) before blood cultures are obtained. The TL could, unintentionally, end up in a blood culture vial, possibly altering the results. The aim of this study was to investigate the effect of the TLs on the detection of microbial growth in blood culture vials. Methods: Different lock solutions (taurolidine-citrate-heparin (TCHL), taurolidine, heparin, citrate or NaCl) were added to BD BACTECTM blood culture vials (Plus Aerobic/F, Lytic/10 Anaerobic/F or Peds Plus/F) before spiking with Staphylococcus aureus (ATCC 29213 or a clinical strain) or Escherichia coli (ATCC 25922 or a clinical strain) in the presence and absence of blood. Subsequently, blood culture vials were incubated in the BD BACTEC FX instrument with Time-to-positivity (TTP) as primary outcome. In addition, the effect of the TCHL on a variety of other micro-organisms was tested. Discussion: In the presence of taurolidine, the TTP was considerably delayed or vials even remained negative as compared to vials containing heparin, citrate or NaCl. This effect was dose-dependent. The delayed TTP was much less pronounced in the presence of blood, but still notable. Conclusion: This study stresses the clinical importance of discarding TLs from the CVC before obtaining a blood culture

    The applicability of the central line-associated bloodstream infection (CLABSI) criteria for the evaluation of bacteremia episodes in pediatric oncology patients

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    Background: The aim of this study was to investigate the applicability of the central line-associated bloodstream infection (CLABSI) criteria of the Centers for Disease Control and Prevention in pediatric oncology patients. Methods: Bacteremia episodes from 2020 to 2022 from a prospective cohort of pediatric oncology patients with a central venous catheter were included. Episodes were classified by three medical experts following the CLABSI criteria as either a CLABSI or non-CLABSI (i.e., contamination, other infection source, or mucosal barrier injury-laboratory confirmed bloodstream infection (MBI-LCBI)). Subsequently, they were asked if and why they (dis)agreed with this diagnosis following the criteria. The primary outcome was the percentage of episodes where the experts clinically disagreed with the diagnosis given following the CLABSI criteria. Results: Overall, 84 bacteremia episodes in 71 patients were evaluated. Following the CLABSI criteria, 34 (40%) episodes were classified as CLABSIs and 50 (60%) as non-CLABSIs. In 11 (13%) cases the experts clinically disagreed with the diagnosis following the CLABSI criteria. The discrepancy between the CLABSI criteria and clinical diagnosis was significant; McNemar's test p <.01. Disagreement by the experts with the CLABSI criteria mostly occurred when the experts found an MBI-LCBI a more plausible cause of the bacteremia than a CLABSI due to the presence of a gram negative bacteremia (Pseudomonas aeruginosa n = 3) and/or mucositis. Conclusions: A discrepancy between the CLABSI criteria and the evaluation of the experts was observed. Adding Pseudomonas aeruginosa as an MBI pathogen and incorporating the presence of mucositis in the MBI-LCBI criteria, might increase the applicability

    The CATERPILLAR-study: An assessor blinded randomized controlled trial comparing a taurolidine-citrate-heparin lock solution to a heparin-only lock solution for the prevention of central-line associated bloodstream infections in paediatric oncology patients

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    Background: Taurolidine–citrate(–heparin) lock solutions (TCHL) are suggested as a promising and safe method for the prevention of central-line-associated bloodstream infections (CLABSI). Aim: To investigate the efficacy of TCHL for the prevention of CLABSI in paediatric oncology patients. Methods: An assessor-blinded randomized controlled trial at the Princess Máxima Centre for paediatric oncology, the Netherlands, was performed from 2020 to 2023. Paediatric oncology patients receiving a tunnelled central venous access device (CVAD) were eligible. A total of 462 patients were required to compare the TCHL to the heparin-only lock (HL). Patients were followed-up for the first 90 days after CVAD insertion. The primary outcome was the incidence of the first CLABSI from CVAD insertion until the end of follow-up. Intention-to-treat and per-protocol analyses were performed. Findings: In total, 232 were randomized in the HL and 231 in the TCHL group. A total of 47 CLABSIs were observed. The intention-to-treat analysis showed that a CLABSI was observed in 26 (11.2%) of the HL group patients versus 21 (9.1%) of the TCHL group patients; incidence rate ratio (IRR) of 0.81 (95% confidence interval (CI): 0.46–1.45) in favour of the TCHL group. The per-protocol analysis showed that a CLABSI was observed in 10 (7.9%) of the HL group patients versus 6 (4.8%) of the TCHL group patients; IRR of 0.59 (95% CI: 0.21–1.62) in favour of the TCHL group. Adverse events were more common in the TCHL group but rarely reported. Conclusion: No difference was detected between the TCHL and HL in the incidence of CLABSI in paediatric oncology patients

    Natural History of Mandibular Function in Spinal Muscular Atrophy Types 2 and 3

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    Background: Hereditary proximal spinal muscular atrophy (SMA) is characterized by abnormal alpha motor neuron function in brainstem and spinal cord. Bulbar dysfunction, including limited mouth opening, is present in the majority of patients with SMA but it is unknown if and how these problems change during disease course. Objective: In this prospective, observational, longitudinal natural history study we aimed to study bulbar dysfunction in patients with SMA types 2 and 3. Methods: We included 44 patients with SMA types 2 and 3 (mean age was 33.6 (95% CI 28.4;38.9) and re-examined them after on average 4 years. None were treated with SMN-modulating treatments before or during the course of this study. Longitudinal assessments included a questionnaire on mandibular and bulbar function, the Mandibular Function Impairment Questionnaire (MFIQ), and a clinical examination of masticatory performance, maximum voluntary bite force, and mandibular movements including the active maximal mouth opening. Results: We found significant higher MFIQ scores and a significant decrease of all mandibular movements in patients with SMA type 2 (p < 0.001), but not in SMA type 3. Masticatory performance and maximum voluntary bite force did not change significantly. Mean reduction of active maximal mouth opening at follow-up was 3.5 mm in SMA type 2 (95%CI: 2.3; 4.7, p < 0.001). SMA type 2 was an independent predictor for a more severe reduction of the mouth opening (β = –2.0 mm (95%CI: –3.8; –0.1, p = 0.043)). Conclusions: Bulbar functions such as mandibular mobility and active maximum mouth opening decrease significantly over the course of four years in patients with SMA type 2

    Incidence of cancer in the area around Amsterdam Airport Schiphol in 1988–2003: a population-based ecological study

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    BACKGROUND: Amsterdam Airport Schiphol is a major source of complaints about aircraft noise, safety risks and concerns about long term adverse health effects, including cancer. We investigated whether residents of the area around Schiphol are at higher risk of developing cancer than the general Dutch population. METHODS: In a population-based study using the regional cancer registry, we estimated the cancer incidence during 1988–2003 in residents of the area surrounding Schiphol. We defined a study area based on aircraft noise contours and 4-digit postal code areas, since historical data on ambient air pollution were not available and recent emission data did not differ from the background urban air quality. RESULTS: In residents of the study area 13 207 cancer cases were diagnosed, which was close to the expected number, using national incidence rates as a reference (standardized incidence ratio [SIR] 1.02). We found a statistically significantly increased incidence of hematological malignancies (SIR 1.12, 95% confidence interval [CI]: 1.05, 1.19), mainly due to high rates for non-Hodgkin lymphoma (SIR 1.22, 95% CI: 1.12, 1.33) and acute lymphoblastic leukemia (SIR 1.34, 95% CI: 0.95, 1.83). The incidence of cancer of the respiratory system was statistically significantly decreased (SIR 0.94, 95% CI: 0.90, 0.99), due to the low rate in males (SIR 0.89). In the core zone of the study area, cancer incidence was slightly higher than in the remaining ring zone (rate ratio of the core zone compared to the ring zone 1.05, 95% CI 1.01, 1.10). This was caused by the higher incidence of cancer of the respiratory system, prostate and the female genital organs in the core zone in comparison to the ring zone. CONCLUSION: The overall cancer incidence in the Schiphol area was similar to the national incidence. The moderately increased risk of hematological malignancies could not be explained by higher levels of ambient air pollution in the Schiphol area. This observation warrants further research, for example in a study with focus on substances in urban ambient air pollution, as similar findings were observed in Greater Amsterdam

    Analogue peptides for the immunotherapy of human acute myeloid leukemia

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    Accepted manuscript. The final publication is available at: http://link.springer.com/article/10.1007%2Fs00262-015-1762-9The use of peptide vaccines, enhanced by adjuvants, has shown some efficacy in clinical trials. However, responses are often short-lived and rarely induce notable memory responses. The reason is that self-antigens have already been presented to the immune system as the tumor develops, leading to tolerance or some degree of host tumor cell destruction. To try to break tolerance against self-antigens, one of the methods employed has been to modify peptides at the anchor residues to enhance their ability to bind major histocompatibility complex molecules, extending their exposure to the T-cell receptor. These modified or analogue peptides have been investigated as stimulators of the immune system in patients with different cancers with variable but sometimes notable success. In this review we describe the background and recent developments in the use of analogue peptides for the immunotherapy of acute myeloid leukemia describing knowledge useful for the application of analogue peptide treatments for other malignancies
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