The Impact of Non-Invasive Ventilation on Sleep Quality in COPD Patients.

BACKGROUND: Non-invasive ventilation (NIV) has been shown to be the most appropriate therapy for COPD patients with chronic respiratory failure. While physiological parameters and long-term outcome frequently serve as primary outcomes, very few studies have primarily addressed the impact of NIV initiation on sleep quality in COPD. METHODS: This single-center prospective cohort study comprised NIV-naïve patients with COPD. All patients underwent polysomnographic evaluation both at baseline and at 3 months follow-up, accompanied by the assessment of health-related quality of life (HRQL) using the Severe Respiratory Insufficiency Questionnaire (SRI) and the Epworth Sleepiness Scale (ESS). A subgroup evaluation was performed to address the impact of comorbid obstructive sleep apnea syndrome (OSAS). RESULTS: Forty-six patients were enrolled and twenty-five patients completed the follow-up period (66.7 ± 7.4 years). NIV resulted in an increase in slow-wave sleep (+2% (-3.5/7.5), p = 0.465) and rapid eye movement sleep (+2.2% (-1.0/5.4), p = 0.174), although no statistical significance could be detected. ESS (-1.7(-3.6/0.1), p = 0.066) also showed a positive trend. Significant improvements in the Respiratory Disturbance Index (RDI) (-12.6(-23.7/-1.5), p = 0.027), lung function parameters, transcutaneous PCO2 and the SRI summary scale (4.5(0.9/8), p = 0.016) were observed. CONCLUSION: NIV therapy does not decrease sleep quality and is even capable of improving HRQL, transcutaneous PaCO2, daytime sleepiness and RDI, and the latter especially holds true for patients with comorbid OSAS.

Altered neurodevelopmental DNA methylation status after fetal growth restriction with brain-sparing.

It is under debate how preferential perfusion of the brain (brain-sparing) in fetal growth restriction (FGR) relates to long-term neurodevelopmental outcome. Epigenetic modification of neurotrophic genes by altered fetal oxygenation may be involved. To explore this theory, we performed a follow-up study of 21 FGR children, in whom we prospectively measured the prenatal cerebroplacental ratio (CPR) with Doppler sonography. At 4 years of age, we tested their neurodevelopmental outcome using the Wechsler Preschool and Primary Scale of Intelligence, the Child Behavior Checklist, and the Behavior Rating Inventory of Executive Function. In addition, we collected their buccal DNA to determine the methylation status at predefined genetic regions within the genes hypoxia-inducible factor-1 alpha (HIF1A), vascular endothelial growth factor A (VEGFA), erythropoietin (EPO), EPO-receptor (EPOR), brain-derived neurotrophic factor (BDNF), and neurotrophic tyrosine kinase, receptor, type 2 (NTRK2) by pyrosequencing. We found that FGR children with fetal brain-sparing (CPR <1, n = 8) demonstrated a trend (0.05 < p < 0.1) toward hypermethylation of HIF1A and VEGFA at their hypoxia-response element (HRE) compared with FGR children without fetal brain-sparing. Moreover, in cases with fetal brain-sparing, we observed statistically significant hypermethylation at a binding site for cyclic adenosine monophophate response element binding protein (CREB) of BDNF promoter exon 4 and hypomethylation at an HRE located within the NTRK2 promoter (both p <0.05). Hypermethylation of VEGFA was associated with a poorer Performance Intelligence Quotient, while hypermethylation of BDNF was associated with better inhibitory self-control (both p <0.05). These results led us to formulate the hypothesis that early oxygen-dependent epigenetic alterations due to hemodynamic alterations in FGR may be associated with altered neurodevelopmental outcome in later life. We recommend further studies to test this hypothesis.

Interactions between magnetite and humic substances: redox reactions and dissolution processes.

Humic substances (HS) are redox-active compounds that are ubiquitous in the environment and can serve as electron shuttles during microbial Fe(III) reduction thus reducing a variety of Fe(III) minerals. However, not much is known about redox reactions between HS and the mixed-valent mineral magnetite (Fe3O4) that can potentially lead to changes in Fe(II)/Fe(III) stoichiometry and even dissolve the magnetite. To address this knowledge gap, we incubated non-reduced (native) and reduced HS with four types of magnetite that varied in particle size and solid-phase Fe(II)/Fe(III) stoichiometry. We followed dissolved and solid-phase Fe(II) and Fe(III) concentrations over time to quantify redox reactions between HS and magnetite. Magnetite redox reactions and dissolution processes with HS varied depending on the initial magnetite and HS properties. The interaction between biogenic magnetite and reduced HS resulted in dissolution of the solid magnetite mineral, as well as an overall reduction of the magnetite. In contrast, a slight oxidation and no dissolution was observed when native and reduced HS interacted with 500 nm magnetite. This variability in the solubility and electron accepting and donating capacity of the different types of magnetite is likely an effect of differences in their reduction potential that is correlated to the magnetite Fe(II)/Fe(III) stoichiometry, particle size, and crystallinity. Our study suggests that redox-active HS play an important role for Fe redox speciation within minerals such as magnetite and thereby influence the reactivity of these Fe minerals and their role in biogeochemical Fe cycling. Furthermore, such processes are also likely to have an effect on the fate of other elements bound to the surface of Fe minerals.

Inflammatory macrophages induce Nrf2 transcription factor-dependent proteasome activity in colonic NCM460 cells and thereby confer anti-apoptotic protection.

Adaptation of epithelial cells to persistent oxidative stress plays an important role in inflammation-associated carcinogenesis. This adaptation process involves activation of Nrf2 (nuclear factor-E2-related factor-2), which has been recently shown to contribute to carcinogenesis through the induction of proteasomal gene expression and proteasome activity. To verify this possible link between inflammation, oxidative stress, and Nrf2-dependent proteasome activation, we explored the impact of inflammatory (M1) macrophages on the human colon epithelial cell line NCM460. Transwell cocultures with macrophages differentiated from granulocyte monocyte-colony-stimulating factor-treated monocytes led to an increased activity of Nrf2 in NCM460 cells along with an elevated proteasome activity. This higher proteasome activity resulted from Nrf2-dependent induction of proteasomal gene expression, as shown for the 19 and 20 S subunit proteins S5a and α5, respectively. These effects of macrophage coculture were preceded by an increase of reactive oxygen species in cocultured NCM460 cells and could be blocked by catalase or by the reactive oxygen species scavenger Tiron, whereas transient treatment of NCM460 cells with H(2)O(2) similarly led to Nrf2-dependent proteasome activation. Through the Nrf2-dependent increase of proteasomal gene expression and proteasome activity, the sensitivity of NCM460 cells to tumor necrosis factor-related apoptosis-inducing ligand- or irinotecan-induced apoptosis declined. These findings indicate that inflammatory conditions such as the presence of M1 macrophages and the resulting oxidative stress are involved in the Nrf2-dependent gain of proteasome activity in epithelial cells, e.g. colonocytes, giving rise of greater resistance to apoptosis. This mechanism might contribute to inflammation-associated carcinogenesis, e.g. of the colon.

Binding of the transcription factor Slug to the L1CAM promoter is essential for transforming growth factor-ß1 (TGF-ß)-induced L1CAM expression in human pancreatic ductal adenocarcinoma cells.

Members of the Slug/Snail family of transcription factors are thought to drive epithelial-mesenchymal-transition (EMT) in preneoplastic epithelial cells, thereby contributing to malignant transformation. One mediator in the EMT of pancreatic ductal adenocarcinoma (PDAC) cells and a potential target gene of Slug is the cellular adhesion molecule L1CAM. Using the human pancreatic ductal epithelial cell line H6c7 and the PDAC cell line Panc1, we could show that along with TGF-ß1-induced EMT, L1CAM expression is increased in a Slug- but not Snail-dependent fashion. Two E-box recognition motifs in the L1CAM promoter upstream of the most distal transcriptional start site could be verified by gel shift and supershift assay to interact with Slug. ChIP assays detected an increased interaction of Slug with both recognition motifs of the human L1CAM promoter in TGF-ß1-treated H6c7 cells, whereas binding of Snail was downregulated. Moreover, ChIP assays with Panc1 cells confirmed this interaction of Slug with the human L1CAM promoter and further detected an interaction of both recognition sites with RNA-polymerase II in a Slug-dependent fashion. Luciferase reporter gene assays using wild-type or single- and double-mutated variants of the L1CAM promoter confirmed transcriptional activation by Slug involving both recognition motifs. By demonstrating the direct transcriptional control of L1CAM expression through Slug during TGF-ß1-induced EMT of PDAC cells, our findings point to a novel mechanism by which Slug contributes quite early to tumorigenesis. Moreover, our study is the first one describing the control of the human L1CAM promoter in tumor cells.

Rates and extent of reduction of Fe(III) compounds and O2 by humic substances.

Humic substances (HS) can be reduced by microorganisms and oxidized by electron acceptors such as Fe(III) or O2. However, redox reactions between HS and highly crystalline Fe(III) minerals and O2 have not yet been quantified. We therefore determined the rates and extent of goethite and hematite reduction by HS in comparison to those of dissolved and poorly crystalline Fe(III) compounds and O2. Although nonreduced HS transferred significant amounts of electrons only to dissolved Fe(III) citrate and ferrihydrite, reduced HS additionally reduced goethite and hematite. The extent of reduction depended on the redox potentials of the Fe(III) compounds. Fewer electrons were transferred from HS to O2 than to Fe(III) despite the more positive redox potential of the O2/H2O redox couple. Reoxidation of reduced HS by O2 took place within minutes and yielded reoxidized HS that were still more reduced than nonreduced HS, indicating that some reduced moieties in HS are protected from reoxidation by O2. Our data suggests (i) reduction of crystalline Fe(III) minerals by reduced HS has to be considered in the environmental electron transfer network, (ii) exposure of reduced HS to O2 does not reoxidize HS completely within short time frames, and therefore, (iii) HS electron shuttling to Fe(III) can occur even in the presence of O2.

Arsenic redox changes by microbially and chemically formed semiquinone radicals and hydroquinones in a humic substance model quinone.

Arsenic is a redox-active metalloid whose toxicity and mobility strongly depends on its oxidation state, with arsenite (As(III)) being more toxic and mobile than arsenate (As(V)). Humic substances (HS) are also redox-active and can potentially react with arsenic and change its redox state. In this study we show that semiquinone radicals produced during microbial or chemical reduction of a HS model quinone (AQDS, 9,10-anthraquinone-2,6-disulfonic acid) are strong oxidants. They oxidize arsenite to arsenate, thus decreasing As toxicity and mobility. This reaction depends strongly on pH with more arsenite (up to 67.3%) being oxidized at pH 11 compared to pH 7 (12.6% oxidation) and pH 3 (0.5% oxidation). In addition to As(III) oxidation by semiquinone radicals, hydroquinones that were also produced during quinone reduction reduced As(V) to As(III) at neutral and acidic pH values (less than 12%) but not at alkaline pH. In order to understand redox reactions between arsenite/arsenate and reduced/oxidized HS, we quantified the radical content in reduced quinone solutions and constructed Eh-pH diagrams that explain the observed redox reactions. The results from this study can be used to better predict the fate of arsenic in the environment and potentially explain the occurrence of oxidized As(V) in anoxic environments.

A randomized clinical trial to evaluate the safety and efficacy of a percutaneous left ventricular assist device versus intra-aortic balloon pumping for treatment of cardiogenic shock caused by myocardial infarction.

OBJECTIVES: The aim of this study was to test whether the left ventricular assist device (LVAD) Impella LP2.5 (Abiomed Europe GmbH, Aachen, Germany) provides superior hemodynamic support compared with the intra-aortic balloon pump (IABP). BACKGROUND: Cardiogenic shock caused by left ventricular failure is associated with high mortality in patients with acute myocardial infarction (AMI). An LVAD may help to bridge patients to recovery from left ventricular failure. METHODS: In a prospective, randomized study, 26 patients with cardiogenic shock were studied. The primary end point was the change of the cardiac index (CI) from baseline to 30 min after implantation. Secondary end points included lactic acidosis, hemolysis, and mortality after 30 days. RESULTS: In 25 patients the allocated device (n = 13 IABP, n = 12 Impella LP2.5) could be safely placed. One patient died before implantation. The CI after 30 min of support was significantly increased in patients with the Impella LP2.5 compared with patients with IABP (Impella: DeltaCI = 0.49 +/- 0.46 l/min/m(2); IABP: DeltaCI = 0.11 +/- 0.31 l/min/m(2); p = 0.02). Overall 30-day mortality was 46% in both groups. CONCLUSIONS: In patients presenting with cardiogenic shock caused by AMI, the use of a percutaneously placed LVAD (Impella LP 2.5) is feasible and safe, and provides superior hemodynamic support compared with standard treatment using an intra-aortic balloon pump. (Efficacy Study of LV Assist Device to Treat Patients With Cardiogenic Shock [ISAR-SHOCK]; NCT00417378).

Medical inpatients at risk of extended hospital stay and poor discharge health status: detection with COMPRI and INTERMED.

OBJECTIVE: To detect the patients in medical wards at risk of extended LOS and poor discharge health status with the use of complexity prediction instrument (COMPRI) and interdisciplinary medicine (INTERMED) instruments. METHODS: STUDY 1: In a sample of 275 consecutively admitted medical inpatients, a hierarchical cluster analysis on INTERMED variables was performed. The clusters were compared on length of hospital stay (LOS) and Short Form 36 (SF-36) at discharge. STUDY 2: Receiver operating characteristic (ROC) analysis was used to optimal cut-off points for the COMPRI and INTERMED. Patients detected with COMPRI and INTERMED were then compared with undetected patients on LOS and SF-36. RESULTS: STUDY 1: In concordance with previous findings, a cluster of patients with high biopsychosocial vulnerability was identified with significantly higher scores on LOS (p <.05) and lower scores on SF-36 (p <.001) than patients in other clusters. STUDY 2: A cut-off point for the COMPRI of 5/6 was found to detect patients at risk of long LOS. A cut off score for the INTERMED of 20/21 was found to detect patients at risk of poor discharge health status. Patients detected with COMPRI and INTERMED had a significantly longer LOS (p <.001) and a poorer discharge health status (SF-36 MCS: p <.001; SF-36 PCS: p =.05) than nondetected patients. Of the detected patients, 37% had an extended hospital stay and poor discharge health status; of the nondetected patients, this was only 7%. CONCLUSIONS: The COMPRI-INTERMED can help to detect complex patients admitted to medical wards within the first days of admission, and rule out those with a small chance of poor outcomes.