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Reliability and relevance of fair values : private equity investments and investee fundamentals
(2018)
We directly test the reliability and relevance of fair values reported by listed private equity firms (LPEs), where the unit of account for fair value measurement attribute (FVM) is an investment stake in an individual investee company. FVMs are observable for multiple investment stakes, fair values are economically important, and granular data on investee economic fundamentals that should underpin fair values are available in public disclosures. We find that LPE fund managers determine valuations based on accounting-based fundamentals—equity book value and net income—that are in line with those investors derive for listed companies. Additionally, our findings suggest that LPE fund managers apply a lower valuation weight to investee net income if direct market inputs are unobservable during investment value estimation. We interpret these findings as evidence that LPE fund managers do not appear mechanically to apply market valuation weights for publicly traded investees when determining valuations of non-listed. We also document that the judgments that LPE fund managers apply when determining investee valuations appear to be perceived as reliable by their investors.
We study the impact of transparency on liquidity in OTC markets. We do so by providing an analysis of liquidity in a corporate bond market without trade transparency (Germany), and comparing our findings to a market with full post-trade disclosure (the U.S.). We employ a unique regulatory dataset of transactions of German financial institutions from 2008 until 2014 to find that: First, overall trading activity is much lower in the German market than in the U.S. Second, similar to the U.S., the determinants of German corporate bond liquidity are in line with search theories of OTC markets. Third, surprisingly, frequently traded German bonds have transaction costs that are 39-61 bp lower than a matched sample of bonds in the U.S. Our results support the notion that, while market liquidity is generally higher in transparent markets, a sub-set of bonds could be more liquid in more opaque markets because of investors "crowding" their demand into a small number of more actively traded securities.
This paper analyzes how the combination of borrowing constraints and idiosyncratic risk affects the equity premium in an overlapping generations economy. I find that introducing a zero-borrowing constraint in an economy without idiosyncratic risk increases the equity premium by 70 percent, which means that the mechanism described in Constantinides, Donaldson, and Mehra (2002) is dampened because of the large number of generations and production. With social security the effect of the zero-borrowing constraint is a lot weaker. More surprisingly, when I introduce idiosyncratic labor income risk in an economy without a zero-borrowing constraint, the equity premium increases by 50 percent, even though the income shocks are independent of aggregate risk and are not permanent. The reason is that idiosyncratic risk makes the endogenous natural borrowing limits much tighter, so that they have a similar effect to an exogenously imposed zero-borrowing constraint. This intuition is confirmed when I add idiosyncratic risk in an economy with a zero-borrowing constraint: neither the equity premium nor the Sharpe ratio change, because the zero-borrowing constraint is already tighter than the natural borrowing limits that result when idiosyncratic risk is added.
Gout is the most common arthritic disease in human but was long neglected and therapeutic options are not satisfying. However, with the recent approval of the urate transporter inhibitor lesinurad, gout treatment has experienced a major innovation. Here we show that lesinurad possesses considerable modulatory potency on peroxisome proliferator-activated receptor γ (PPARγ). Since gout has a strong association with metabolic diseases such as type 2 diabetes, this side-activity appears as very valuable contributing factor to the clinical efficacy profile of lesinurad. Importantly, despite robustly activating PPARγ in vitro, lesinurad lacked adipogenic activity, which seems due to differential coactivator recruitment and is characterized as selective PPARγ modulator (sPPARγM).
An der Goethe-Universität wurden im Wintersemester 2017/18 alle Studierenden grundständiger Studiengänge und Masterstudiengänge für die zweite universitätsweite Studierendenbefragung eingeladen (n=45.343) und gebeten Fragen zu ihrer Lebenswirklichkeit und Studiensituation, ihrem soziodemographischen oder bildungsbiographischen Hintergrund zu beantworten sowie Studienbedingungen und Lehrqualität einzuschätzen.
Das Ziel des vorliegenden Gesamtberichts ist die Dokumentation der universitätsweiten Befragungsergebnisse. Insgesamt konnten Antworten von 10.797 Studierende (Rücklauf 24%) in die Auswertungen aufgenommen werden. ...
Kidney injury is a common complication of severe disease. Here, we report that injuries of the zebrafish embryonal kidney are rapidly repaired by a migratory response in 2-, but not in 1-day-old embryos. Gene expression profiles between these two developmental stages identify cxcl12a and myca as candidates involved in the repair process. Zebrafish embryos with cxcl12a, cxcr4b, or myca deficiency display repair abnormalities, confirming their role in response to injury. In mice with a kidney-specific knockout, Cxcl12 and Myc gene deletions suppress mitochondrial metabolism and glycolysis, and delay the recovery after ischemia/reperfusion injury. Probing these observations in zebrafish reveal that inhibition of glycolysis slows fast migrating cells and delays the repair after injury, but does not affect the slow cell movements during kidney development. Our findings demonstrate that Cxcl12 and Myc facilitate glycolysis to promote fast migratory responses during development and repair, and potentially also during tumor invasion and metastasis.
This study was designed to investigate whether epigenetic modulation by histone deacetylase (HDAC) inhibition might circumvent resistance towards the mechanistic target of rapamycin (mTOR) inhibitor temsirolimus in a prostate cancer cell model. Parental (par) and temsirolimus-resistant (res) PC3 prostate cancer cells were exposed to the HDAC inhibitor valproic acid (VPA), and tumor cell adhesion, chemotaxis, migration, and invasion were evaluated. Temsirolimus resistance was characterized by reduced binding of PC3res cells to endothelium, immobilized collagen, and fibronectin, but increased adhesion to laminin, as compared to the parental cells. Chemotaxis, migration, and invasion of PC3res cells were enhanced following temsirolimus re-treatment. Integrin α and β receptors were significantly altered in PC3res compared to PC3par cells. VPA significantly counteracted temsirolimus resistance by down-regulating tumor cell–matrix interaction, chemotaxis, and migration. Evaluation of integrin expression in the presence of VPA revealed a significant down-regulation of integrin α5 in PC3res cells. Blocking studies demonstrated a close association between α5 expression on PC3res and chemotaxis. In this in vitro model, temsirolimus resistance drove prostate cancer cells to become highly motile, while HDAC inhibition reversed the metastatic activity. The VPA-induced inhibition of metastatic activity was accompanied by a lowered integrin α5 surface level on the tumor cells.
In the first part of the thesis we investigate Lyapunov exponents for general flat vector bundles over Riemann surfaces and we describe properties of Lyapunov exponents on special loci of the moduli space of flat vector bundles. In the second part of the thesis we show how the knowledge of Lyapunov exponent over a sporadic Teichmüller curve can be used to compute the algebraic equation of the associated universal family of curves.
The role of the homeobox transcription factor Meis2b in zebrafish heart development and asymmetry
(2018)
Zebrafish heart development: The heart of the zebrafish is the first organ to form and function during embryonic development, and is composed by one atrium and one ventricle. Between 5-17 somites stage, the cardiomyocyte precursors form the bilateral cardiac fields in the anterior lateral plate mesoderm (ALMP); where the endocardial precursors are located anterior to the cardiac fields (Zeng, Wilm et al. 2007). Then, the pools of endocardial andmyocardial precursors fuse at the midline and form the heart disc; where atrial cardiomyocytes are located around, the ventricular cardiomyocytes are located in the centerof the heart disc, and the future endocardium is located in a ventral position relative to the cardiomyocytes (Bakkers 2011). After the heart disc is formed, the cardiomyocyte progenitors start to migrate and rotate asymmetrically to form the heart tube (de Campos-Baptista, Holtzman et al. 2008, Rohr, Otten et al. 2008, Smith, Chocron et al. 2008). This process is followed by a rightward bending of the heart tube, and the arterial and venous poles rotate at different speed and directions (a process known as heart looping) (Smith, Chocron et al. 2008). The heart looping process results in a ventricle located on the right side and a more posterior atrium located on the left side with respect to the midline; at this point the atrium and ventricle are separated by a fine segment called the atrioventricular canal, where the valves will be formed (Staudt and Stainier 2012). The second heart field (SHF) is a pool of cardiac progenitors that are specified later during the formation of the heart disc and until the heart looping stages. The SHF contributes withcells to the distal side of the ventricle, the outflow and inflow tracts, and is important for the specification of the cardiac conduction system (de Pater, Clijsters et al. 2009, Hami, Grimes et al. 2011, Zhou, Cashman et al. 2011, Witzel, Jungblut et al. 2012, Guner-Ataman, Paffett-Lugassy et al. 2013)....
Whereas many writers across all times and cultures have written about the potential aesthetic effects of music experiences which could be labeled as absorption, only limited empirical research has been done on the state aspects of this fascinating aspect of human involvement. What is more, there are still few tested models which explain how people can be absorbed by a piece of music as well as continue to be third-person observers monitoring and even reflecting on that same musical experience (cf. Bryant & Veroff, 2007; Dewey, 2005; Wolf, 2013).
Adopting a dual process approach (Dietrich, 2004; Evans & Stanovich, 2013; Lewis, Tamborini & Weber, 2014; Mukhopadhyay, 2014; Schwarz, 2011; Smith & Neumann, 2005) – in which human thinking, emotion, and routes to appraisal are defined in terms of an interplay between two distinct systems of psychological processing – this thesis aimed to examine a) the cognitive mechanisms underlying the essential yet poorly understood paradox of losing oneself in the music on the one hand, and the act of meta-awareness (i.e., rational and controlled sense of self) on the other, b) its corresponding psycho-phenomenological profile(s) when listening intentionally to self-chosen music, and c) the different potential of state and trait aspects of absorption and meta-awareness in predicting three indicators of the aesthetic response to music: enjoyment (a purely pleasurable response), lasting impression (a meaningful response related to mixed emotion), and behavioral intention (future-planned seeking/ avoidance response). Moreover, a dynamically-conceived conceptualization of absorption was proposed in terms of a temporary phase taking place amidst a variety of other cognitive responses to music, including concentration, mind wandering, and mindfulness. Finally, a questionnaire commonly-used for assessing alterations in consciousness (Phenomenology of Consciousness Inventory; Pekala, 1991) was evaluated in the context of music listening, before using it in the development of a self-report questionnaire aimed at measuring absorptive states in or by music. To this end, a quantitative empirical research method (state and trait questionnaires) was employed in a series of online surveys, using self-selected music as well as pre-determined music by the researcher as stimulus, together approaching a naturalistic listening setting.
Situated within an overarching neurocognitive model for music engagement and consistent with several aesthetic theories converging (Benson, 1993; Dewey, 2005; Wolf, 2013), aesthetic absorption was conceptualized as, and later confirmed to be, structured by experiential and meta-consciousness or – in terms of dual process terminology – intuitive type I and reflective type II processing. Two forms of music absorption were empirically identified and labeled as zoning in and tuning in (cf. Schooler, 2007). These experience profiles distinguished themselves significantly in terms of the degree in which a music listener maintained his or her meta-awareness, assessed via volitional control, rationality, self-awareness, and memory of the previous event. The overall pattern of consciousness parameters of both types of absorbed listening are suggestive of a unique interchanging between brain networks for intuitive processing and areas related to self-reference, -awareness and -control. The distinction between zoning in and tuning in was further found to be strongly related to the quality of affective state (i.e., positive vs. mixed emotions). These emotions modulate the experiential intensity of absorption, suggesting this experience to be an affect-biased type of attention. Based on the feelings-as-information theory (Schwarz, 2011), postulating that positive emotions (e.g., happiness) are differently processed than negatively-tinted types of emotions (e.g., nostalgia), it was concluded that music-induced rumination (a negatively-valenced experience related to the self and represented by the feeling of sadness) ‘competes’ with higher-order functions relevant to meta-awareness. From this perspective, the two found absorption types match conceptually with the positively-tinged self-reflection and negatively-tinged self-rumination as two different types of self-focused introspection (Takano & Tanno, 2009; Trapnell & Campbell, 1999). Further examining the construct’s latent structure, it was shown that being absorbed by music is a continuous phenomenon; a matter of ‘more-or-less’ involvement rather than a ‘unique state of mind’. This finding cautions against subtyping absorption experiences as being qualitatively distinct, and assuming it to be guided by ‘special’ mechanisms. Consequently, determining ‘music absorbers’ is a matter of imprecise estimation rather than being marked by a clear observable onset. Finally, as expected, an absorbed state of mind – operationalized here as a multidimensional bifactor model – completely mediated the effect of trait absorption, and was a good predictor for enjoyment, lasting impression, and behavioral intention. Whereas absorption and enjoyment were found to have a mutual positive effect on each other, absorption and meta-awareness were found to be unrelated to each other. Also, meta-awareness contributed little to aesthetic appreciation. The results confirm the need for a dynamic approach to the relationship between state absorption and enjoyment; the one-directional approach common in many research reports does not seem to fully capture the relationship between them. Future research should examine whether the same applies for absorption and meta-awareness, preferably making use of more advanced measures for the latter.
Taken together, this dissertation shows the potential of including the interplay between the trait and state constructs of absorption and meta-awareness in order to better understand the mechanisms underlying aesthetic experiences with music. The present work demonstrated that these two constructs should not be conflated, but, in terms of dual processing, that they represent different levels of consciousness. Moreover, this thesis underlined the power of absorption not only to evoke short-lived pleasurable experiences, but also to stimulate long-lasting impressions. Knowing more about absorbed listening and its potential effects, learning to consciously recognize it as it happens, and perhaps regulate and maintain its positive consequences (i.e., savoring), could further improve the way we engage ourselves with music or other aesthetic objects. Only then could we engage in behavior that we’re sure would make us happy rather than seeking out experiences which we hope would make us happy.
Finally, dual process approach and measures provided by research on altered-states-of-consciousness (ASC) experiences offer new and fruitful perspectives to conceptualize aesthetic absorption and examine its mechanisms. Several major research questions lie ahead in understanding the phenomenological experience and aesthetic role of absorption, including the future comparison between subjective experiences of ASCs across varying music and non-music induction methods (e.g., hypnosis), listening conditions (e.g., live concert experience), and musical ‘cultures’ (human societies, musical styles, classes).
Das Ziel der vorliegenden Arbeit war es, MALDI-Massenspektrometrie als robuste Analysenmethode für die quantitative Analyse niedermolekularer Verbindungen aus komplexen biologischen Matrizes zu etablieren. Zu Beginn der Arbeit wurden drei typische Fragestellungen im Bereich der Lebensmittelanalytik, der medizinischen Forschung und der klinischen Chemie ausgewählt, um die Methodik anhand dieser Modellsysteme zielgerichtet zu entwickeln und zu bewerten. Für jede dieser Fragestellungen wird routinemäßig ein hoher Probendurchsatz verlangt und damit werden hohe Anforderungen an die Probenvorbereitung gestellt, da diese einfach, schnell, reproduzierbar, Matrix-tolerant und automatisierbar sein muss um die Weiterentwicklung zur Hochdurchsatzanalytik zu erlauben.
Der quantitative Nachweis von Melamin und seinen Derivaten wurde aufgrund des Aufkommens von Milchprodukten, die mit diesen Verbindungen kontaminiert waren, ein wichtiger Bestandteil der Analytik dieser Lebensmittel. Insbesondere an diesem Beispiel zeigte sich der Vorteil des Einsatzes von MALDI-Massenspektrometrie zur Analyse kleiner Moleküle. Aufgrund der höheren Toleranz gegenüber Puffern und Salzen konnte die Probenvorbereitungszeit der für die FDA entwickelten Methode zur Quantifizierung von Melamin in Milchpulver mittels LC-ESI von ca. 140 min auf 90 min reduziert werden, da auf die zeitaufwendige Flüssigchromatographie verzichtet werden konnte. So wurde Melamin mit einem LLOQ von 0,5 ppm quantifiziert, was unterhalb der Vorgaben der WHO (2,5 ppm in Milichpulver und 1 ppm in Babynahrung) lag. Cyanursäure, ein Derivat von Melamin welches für die Bildung schwerlöslicher Komplexe in der Niere mitverantwortlich gemacht wird, konnte ebenfalls mit der entwickelten MALDI-MS Methode quantifiziert werden. Allerdings war die ermittelte Bestimmungsgrenze mit 15 ppm um den Faktor 30 schlechter als bei Melamin. Die Nachweisgrenze bei MALDI-MS ist stark von der MALDI-Matrix abhängig und die Verwendung von Sinapinsäure war eine gute Kompromisslösung, um die Analyten in einem Spot im positiven und negativen Reflektormodus zu analysieren. Allerdings wurde diese Matrix zur Analyse von Analyten im positiven Reflektormodus entwickelt. Bislang wurden nur wenige Matrizes für MALDI-MS im negativen Reflektormodus beschrieben, um z.B. Säuren besser nachweisen zu können. Forschung in diesem Bereich wird neue Möglichkeiten zur Detektion negativ geladener kleiner Moleküle ergeben.
Des Weiteren wurden im Rahmen dieser Arbeit auch Lösungen für klinische Fragestellungen wie etwa den Nachweis von Methylphenidat im Plasma und Gehirn von Ratten oder der Dried Blood Spot Analytik entwickelt. Bei beiden Methoden wurde jeweils nur eine einfache Flüssig-Flüssig-Extraktion zur Probenvorbereitung angewendet und sie ließen sich sehr gut auf Realproben übertragen.
Methylphenidat konnte im Plasma im Konzentrationsbereich von 0,1-40 ng/mL und im Hirnhomogenat im Konzentrationsbereich von 0,4-40 ng/mL quantifiziert werden, was gut im Konzentrationsbereich der Realproben von mit Methylphenidat gefütterten Ratten lag. Dazu standen das Plasma und die Gehirne von fünf Ratten zur Verfügung. Es wurde eine lineare Korrelation zwischen der MPH-Konzentration im Gehirnhomogenat und im Plasma gefunden, was basierend auf den bis dato bekannten Literaturergebnissen ein zu erwartendes Ergebnis war, aber zukünftig mit einer größeren Anzahl von Versuchstieren verifiziert werden sollte. Während der Methodenentwicklung war auch bei diesem Projekt die Auswahl der MALDI-Matrix ausschlaggebend für den Erfolg der Messungen. Im MALDI-Massenspektrum interferierte das Signal des Natriumaddukts von CHCA mit dem Signal von MPH. Für dieses Problem kamen zwei mögliche Lösungen in Betracht. Erstens die Quantifizierung mit ClCCA als MALDI-Matrix, da hier keine Interferenzen auftraten. In ersten Vorversuchen konnte MPH so in einem Konzentrationsbereich von 1-48 ng/mL mit einer exzellenten Linearität von R2=0,9992 quantifiziert werden. Eine zweite mögliche Problemlösung war die Verwendung von Tandem-Massenspektrometrie. Hierzu wurden Fragmentionen-Massenspektren der überlagerten Signale aufgenommen. MPH und der verwendete interne Standard MPH-d9 zeigten dabei spezifische Fragmentionensignale, über die quantifiziert wurde. Da die Sensitivität um den Faktor 100 im Vergleich zu MS-Spektren von CHCA und ClCCA gesteigert werden konnte, wurde die weitere Methodenentwicklung basierend auf der Tandem-Massenspektrometrie mit der MALDI-Matrix CHCA durchgeführt. Überdies sind MS/MS-Versuche unter Verwendung von ClCCA als MALDI-Matrix für kleine Moleküle sehr erfolgsversprechend und sollten in weiteren Forschungsarbeiten durchgeführt werden.
Die Dried Blood Spot Technik als alternative Probenvorbereitung bietet eine Reihe von Vorteilen, wie etwa den einer einfacheren Lagerung und eines einfacheren Transports einer großen Menge von Proben. Darüber hinaus werden nur wenige Mikroliter Blut verwendet, was vorteilhaft ist bei z B. klinischen Studien oder dem Therapeutic Drug Monitoring. Diese Art der Probennahme ist somit eine perfekte Ergänzung für weitere quantitative Analysen von Methylphenidat in Rattenblut. Den Ratten würden nur wenige Mikroliter Blut entnommen werden, was ihr Überleben sichert und der Transport der Proben auf dem Postweg wäre wesentlich einfacher. Um eine allgemein verwendbare DBS-MALDI-MS-Methode zu entwickeln, wurden neben Methylphenidat auch bekannte Analyten aus dem Bereich des Dopings sowie Lamotrigin, Coffein und Theophyllin als Beispiele für das Therapeutic Drug Monitoring verwendet. Es wurden verschiedene Lösungsmittel zur Extraktion eingesetzt, wobei sich eine Kombination aus Methyl-tert-Butylether und Ethanol, sowie Aceton als am besten geeignet erwies. Einige Analyten wie Coffein, Theophyllin und Lamotrigin wurden bis zu einer Konzentration von 0,5 μg/mL quantifiziert. Diese Bestimmungsgrenze ist bei Analyten aus dem Bereich des Dopings wie z.B. Salbutamol, Methylphenidat oder Clenbuterol, deren therapeutisch wirksame Plasmakonzentration im Bereich von wenigen Nanogramm pro Milliliter Blut liegt, um den Faktor 15-500 zu hoch. Diese Analyten waren bis zu einer Konzentration von 5 μg/mL im Blut mittels MALDI-MS problemlos nachweisbar. Um die Sensitivität zu erhöhen, ist es allerdings sinnvoll, die Extraktion zukünftig für die einzelnen Analyten zu optimieren, sie mittels Festphasenextraktion oder LC anzureichern und MS/MS-Spektren aufzunehmen. Für die Analyten Coffein, Theophyllin und Lamotrigin, deren therapeutisch wirksame Plasmakonzentration im ein- bis zweistelligen Mikrogramm-pro-Milliliter Bereich liegt, eignete sich die entwickelte Methode sehr gut. Es wurde eine Methodenvalidierung durchgeführt, wobei die validierten Parameter den Vorgaben der FDA entsprachen.
Da die Auswahl der MALDI-Matrix bei den verschiedenen Methodenentwicklungen jeweils ein kritischer Faktor war, wurden abschließend eine Auswahl von Analyten mit einer Molekülmasse bis ca. 600 Da mit verschiedenen MALDI-Matrizes präpariert. Ein Großteil der Analyten wurde am sensitivsten mit ClCCA nachgewiesen. Im Rahmen dieser Versuche wurde auch erstmals ein Strukturanalogon von ClCCA, und zwar ClCCA-Tetrazol, als alternative MALDI-Matrix eingesetzt, bei welchem die Carboxylgruppe durch einen Tetrazolring ausgetauscht wurde. Diese zeigte eine sehr homogene Kristallisation und für einige Analyten eine bis zu Faktor 3 höhere Signalintensität im Vergleich zu ClCCA. Außerdem war auffällig, dass einige Analyten unter bestimmten Präparationsbedingungen wie z B. der Graphite Supported Preparation sensitiver mittels MALDI-MS nachweisbar waren. Bei anderen Analyten verschlechterten sich die Analysenergebnisse. Graphit verändert stark die Kristallisation der MALDI-Matrix und es wird vermutet, dass sich dies auf den Einbau der Analyten in die Matrixkristalle auswirkt. Es konnte bislang aber noch nicht abschließend geklärt werden, wie genau die Präparation der Proben Einfluss auf den Einbau der Analyten in die Matrix nimmt. Eine Untersuchung dieser Phänomene sollte daher Gegenstand weiterer Forschungsprojekte sein.
Zusammenfassend stellt die MALDI-Massenspektrometrie eine schnelle und robuste Methode zur Quantifizierung einer Vielzahl kleiner Moleküle in komplexen biologischen Matrizes dar.
In order to elucidate the causes for the increased mortality of aged patients with bacterial central nervous system (CNS) infections, we compared the course of Streptococcus pneumoniae (S. pneumoniae) meningitis in aged and young mice. Aged (21.2 ± 3.1 months, n = 40) and young (3.2 ± 0.9 months, n = 42) C57BL/6N and B6/SJL mice were infected by intracerebral injection of 50–70 CFU S. pneumoniae serotype 3 and monitored for 15 days. Aged and young mice did not differ concerning mortality (35% versus 38%), weight loss, development of clinical symptoms, bacterial concentrations in cerebellum and spleen as well as the number of leukocytes infiltrating the CNS. In contrast to results from our geriatric mouse model of Escherichia coli (E. coli) meningitis, where aged mice showed a higher mortality and an impaired elimination of bacteria, we did not find any differences between aged and young mice after intracerebral infection with S. pneumoniae serotype 3. This indicates that the increased susceptibility of aged mice to bacterial CNS infections is pathogen-specific: It appears less prominent in infections caused by hardly phagocytable pathogens with thick capsules like S. pneumoniae serotype 3, where the age-related decline of the phagocytic capacity of microglia and macrophages has a minor influence on the disease course.
Cyclin-dependent kinase (CDK) 4/6 inhibitors have shown great results in numerous clinical trials and have improved the clinical outcome for patients with hormone-receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer significantly. To date, three CDK4/6 inhibitors are approved by the US Food and Drug Administration (FDA): palbociclib, ribociclib and abemaciclib; the first two compounds are aproved by the European Medicines Agency (EMA) as well. In combination with endocrine therapy, all of them led to significantly improved progression-free survival compared with endocrine therapy alone. The aim of this article is to give an overview of the efficacy data and to describe the CDK4/6 inhibitor-based treatment-associated adverse events, including hematological and nonhematological adverse events. In addition, it describes the corrrect approach to patient monitoring and adverse event mangement and summarizes the current recommendations for dose reductions and dose interruptions regarding the key adverse events, such as neutropenia, diarrhea, QTc prolongation and hepatobiliary toxicity. Accurate patient monitoring and management of the side effects is crucial, as several clinical trials in early breast cancer are in progress and may lead to an additional approval in the neo-/adjuvant setting.
Aim: To evaluate protective immunosuppressive dose and time-dependent effects of ethanol in an in vitro model of acute inflammation in human Chang liver cells.
Method: The study was performed in 2016 and 2017 in the research laboratory of the Department of Trauma, Hand and Reconstructive Surgery, the University Hospital of the Goethe-University Frankfurt. Chang liver cells were stimu - lated with either interleukin (IL)-1β or IL-6 and subsequent - ly treated with low-dose ethanol (85 mmol/L) or high-dose ethanol (170 mmol/L) for one hour (acute exposure) or 72 hours (subacute exposure). IL-6 and IL-1β release were de - termined by enzyme-linked immunosorbent assay. Neu - trophil adhesion to Chang liver monolayers, production of reactive oxygen species, and apoptosis or necrosis were analyzed.
Results: Contrary to high-dose ethanol, acute low-dose ethanol exposure significantly reduced IL-1β-induced IL-6 and IL-6-induced IL-1β release ( P <0.05). Subacute etha - nol exposure did not change proinflammatory cytokine release. Acute low-dose ethanol exposure significantly decreased inflammation-induced formation of reactive oxygen species ( P <0.05) and significantly improved cell survival ( P <0.05). Neither acute nor subacute high-dose ethanol exposure significantly changed inflammationinduced changes in reactive oxygen species or survival. Acute and subacute ethanol exposure, independently of the dose, significantly decreased neutrophil adhesion to inflamed Chang liver cells ( P <0.05).
Conclusion: Acute treatment of inflamed Chang liver cells with ethanol showed its immunosuppressive potential. However, the observed effects were limited to low-dose setting, indicating the relevance of ethanol dose in the modulation of inflammatory cell response.
Ribosome recycling orchestrated by ABCE1 is a fundamental process in protein translation and mRNA surveillance, connecting termination with initiation. Beyond the plenitude of well-studied translational GTPases, ABCE1 is the only essential factor energized by ATP, delivering the energy for ribosome splitting via two nucleotide-binding sites by a yet unknown mechanism. Here, we define how allosterically coupled ATP binding and hydrolysis events in ABCE1 empower ribosome recycling. ATP occlusion in the low-turnover control site II promotes formation of the pre-splitting complex and facilitates ATP engagement in the high-turnover site I, which in turn drives the structural reorganization required for ribosome splitting. ATP hydrolysis and ensuing release of ABCE1 from the small subunit terminate the post-splitting complex. Thus, ABCE1 runs through an allosterically coupled cycle of closure and opening at both sites, consistent with a processive clamp model. This study delineates the inner mechanics of ABCE1 and reveals why various ABCE1 mutants lead to defects in cell homeostasis, growth, and differentiation.
Background: No observational studies have evaluated the "real-world" effectiveness of dual bronchodilation comprising a long-acting β2-agonist plus a long-acting muscarinic antagonist vs that of triple therapy (long-acting β2-agonist plus long-acting muscarinic antagonist plus inhaled corticosteroid) in COPD.
Materials and methods: DACCORD is a non-interventional, observational clinical study that recruited patients following COPD maintenance therapy initiation or change in maintenance therapy between or within therapeutic class. Given the non-interventional nature of the study, the decision to initiate or change medication had to be made by the patients’ physicians prior to inclusion in DACCORD. We used a matched-pairs analysis to compare disease progression in two patient groups: those receiving dual bronchodilation vs those receiving triple therapy (each group n=1,046).
Results: In two subgroups of patients matched according to a broad range of demographic and disease characteristics, over 1 year, fewer patients receiving dual bronchodilation exacerbated than those receiving triple therapy (15.5% vs 26.6%; P<0.001), with a greater improvement from baseline in COPD Assessment Test total score at 1 year (mean±SD -2.9±5.8 vs -1.4±5.5; P<0.001). When analyzed according to prior therapy, the highest rate of exacerbations was in patients on triple therapy prior to the study who remained on triple therapy. Those changing from mono-bronchodilator to dual bronchodilation had the greatest COPD Assessment Test total score improvement.
Conclusion: In this "real-life" cohort of patients with COPD, most of whom had not exacerbated in the 6 months prior to entry, triple therapy did not seem to improve outcomes compared with dual bronchodilation in terms of either exacerbations or health status. Our analyses clearly demonstrate the potential impact of prior medication on study results, something that should be taken into account when interpreting the results even of controlled clinical trials.
Arachidonate 15-lipoxygenase (ALOX15) and arachidonate 15-lipoxygenase, type B (ALOX15B) catalyze the dioxygenation of polyunsaturated fatty acids and are upregulated in human alternatively activated macrophages (AAMs) induced by Th2 cytokine interleukin-4 (IL-4) and/or interleukin-13. Known primarily for roles in bioactive lipid mediator synthesis, 15-lipoxygenases (15-LOXs) have been implicated in various macrophage functions including efferocytosis and ferroptosis. Using a combination of inhibitors and siRNAs to suppress 15-LOX isoforms, we studied the role of 15-LOXs in cellular cholesterol homeostasis and immune function in naïve and AAMs. Silencing or inhibiting the 15-LOX isoforms impaired sterol regulatory element binding protein (SREBP)-2 signaling by inhibiting SREBP-2 processing into mature transcription factor and reduced SREBP-2 binding to sterol regulatory elements and subsequent target gene expression. Silencing ALOX15B reduced cellular cholesterol and the cholesterol intermediates desmosterol, lanosterol, 24,25-dihydrolanosterol, and lathosterol as well as oxysterols in IL-4-stimulated macrophages. In addition, attenuating both 15-LOX isoforms did not generally affect IL-4 gene expression but rather uniquely impacted IL-4-induced CCL17 production in an SREBP-2-dependent manner resulting in reduced T cell migration to macrophage conditioned media. In conclusion, we identified a novel role for ALOX15B, and to a lesser extent ALOX15, in cholesterol homeostasis and CCL17 production in human macrophages.
In contrast to several smaller studies, which demonstrate that remote ischemic preconditioning (RIPC) reduces myocardial injury in patients that undergo cardiovascular surgery, the RIPHeart study failed to demonstrate beneficial effects of troponin release and clinical outcome in propofol-anesthetized cardiac surgery patients. Therefore, we addressed the potential biochemical mechanisms triggered by RIPC. This is a predefined prospective sub-analysis of the randomized and controlled RIPHeart study in cardiac surgery patients (n = 40) that was recently published. Blood samples were drawn from patients prior to surgery, after RIPC of four cycles of 5 min arm ischemia/5 min reperfusion (n = 19) and the sham (n = 21) procedure, after connection to cardiopulmonary bypass (CPB), at the end of surgery, 24 h postoperatively, and 48 h postoperatively for the measurement of troponin T, macrophage migration inhibitory factor (MIF), stromal cell-derived factor 1 (CXCL12), IL-6, CXCL8, and IL-10. After RIPC, right atrial tissue samples were taken for the measurement of extracellular-signal regulated kinase (ERK1/2), protein kinase B (AKT), Glycogen synthase kinase 3 (GSK-3β), protein kinase C (PKCε), and MIF content. RIPC did not significantly reduce the troponin release when compared with the sham procedure. MIF serum levels intraoperatively increased, peaking at intensive care unit (ICU) admission (with an increase of 48.04%, p = 0.164 in RIPC; and 69.64%, p = 0.023 over the baseline in the sham procedure), and decreased back to the baseline 24 h after surgery, with no differences between the groups. In the right atrial tissue, MIF content decreased after RIPC (1.040 ± 1.032 Arbitrary units [au] in RIPC vs. 2.028 ± 1.631 [au] in the sham procedure, p < 0.05). CXCL12 serum levels increased significantly over the baseline at the end of surgery, with no differences between the groups. ERK1/2, AKT, GSK-3β, and PKCɛ phosphorylation in the right atrial samples were no different between the groups. No difference was found in IL-6, CXCL8, and IL10 serum levels between the groups. In this cohort of cardiac surgery patients that received propofol anesthesia, we could not show a release of potential mediators of signaling, nor an effect on the inflammatory response, nor an activation of well-established protein kinases after RIPC. Based on these data, we cannot exclude that confounding factors, such as propofol, may have interfered with RIPC.
Purpose: There is some controversy whether or not saccades change with age. This cross-sectional study aims to clarify the characteristics of reflexive saccades at various ages to establish a normative cohort in a standardized set-up. Second objective is to investigate the feasibility of saccadometry in daily ophthalmological practice.
Methods: One hundred healthy participants aged between 6 and 76 years underwent an ophthalmologic examination and saccadometry, using an infrared video-oculography device, sampling at 220 Hz. The reflexive saccades were evoked in four directions and three target displacements each (5°/15°/30° horizontally and of 5°/10°/20° vertically). Saccadic peak velocity, gain (amplitude/target displacement) and latency were measured.
Results: Mean peak velocity of saccades was 213°/s (± 29°/s), 352°/s (± 50°/s) and 455°/s (± 67°/s) to a target position 5°, 15°and 30° horizontally, respectively, and 208°/s (± 36°/s), 303°/s (± 50°/s) and 391°/s (± 71°/s) to a target position 5°, 10° and 20° vertically. The association between peak velocity and eccentricity proved to be present at any age in all four directions. We found no relevant effect of age on peak velocity, gain and latency in a fitted linear mixed model. However, latency becomes shorter during childhood and adolescence, while in adulthood it is relatively stable with a slight trend to increase in the elderly. Saccades are more precise when the target displacement is small. Isometric saccades are most common, followed by hypometric ones. All children and elderly were able to perform good quality saccadometry in a recording time of approximately 10 minutes.
Conclusion: The presented data may serve as normative control for further studies using such a video-oculography device for saccadometry. The means of peak velocity and the gain can be used independently from age respecting the target displacement. Latency is susceptible to age.