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Background: Hypernatremia presents a common complication in intensive care unit (ICU) patients, associated with increased mortality and length of stay. This study investigates the effect of sodium chloride 0.9% compared with glucose 5% solution as the standard intravenous drug diluent on the prevalence of hypernatremia in a medical ICU., Methods: This is a retrospective before-and-after study comparing two consecutive patient groups before and after the standard drug solvent was changed from sodium chloride 0.9% to glucose 5% solution for compatible medications. A total of 265 adult COVID-19 patients admitted between October 2020 and March 2021 to the study ICU were included, with 161 patients in the timeframe when sodium chloride 0.9% was employed as the standard drug solvent and 104 patients when glucose 5% was used. Routine sodium measurements from arterial and venous blood gases, along with heparinized lithium plasma, were analyzed. The daily sodium concentrations and the prevalence of severe hypernatremia (>150 mmol/l) were assessed during the first 8 days after ICU admission., Results: Baseline characteristics were similar between the two groups. The cumulative volume of intravenous drug diluents was comparable. In the glucose 5% group, about half of the total drug diluent volume was glucose 5% [mean (SD): 2251.6 (2355.4) ml], compared to 135.0 (746.9) ml ( P  < .001) in the control group. Average sodium concentrations diverged after day two, with the glucose 5% group consistently showing lower sodium levels (mean difference of ∼2.5 mmol/l). Severe hypernatremia occurred less frequently in the glucose 5% group (6.6% vs. 20%)., Conclusion: Glucose 5% solution as the standard intravenous drug solvent significantly reduced sodium concentrations and the occurrence of severe hypernatremia. This simple modification in solvent choice may serve as a preventive strategy against hypernatremia in the ICU. Further prospective research is necessary to determine associated clinical outcomes., Trial Registration: The trial was registered in the German Clinical Trials Register (DRKS00031877)., Competing Interests: None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.)

Chaperonins are large barrel-shaped complexes that mediate ATP-dependent protein folding 1-3 . The bacterial chaperonin GroEL forms juxtaposed rings that bind unfolded protein and the lid-shaped cofactor GroES at their apertures. In vitro analyses of the chaperonin reaction have shown that substrate protein folds, unimpaired by aggregation, while transiently encapsulated in the GroEL central cavity by GroES 4-6 . To determine the functional stoichiometry of GroEL, GroES and client protein in situ, here we visualized chaperonin complexes in their natural cellular environment using cryo-electron tomography. We find that, under various growth conditions, around 55-70% of GroEL binds GroES asymmetrically on one ring, with the remainder populating symmetrical complexes. Bound substrate protein is detected on the free ring of the asymmetrical complex, defining the substrate acceptor state. In situ analysis of GroEL-GroES chambers, validated by high-resolution structures obtained in vitro, showed the presence of encapsulated substrate protein in a folded state before release into the cytosol. Based on a comprehensive quantification and conformational analysis of chaperonin complexes, we propose a GroEL-GroES reaction cycle that consists of linked asymmetrical and symmetrical subreactions mediating protein folding. Our findings illuminate the native conformational and functional chaperonin cycle directly within cells., (© 2024. The Author(s).)

Power can increase overconfidence and illusory thinking. We investigated whether power is also related to the illusion of explanatory depth (IOED), people's tendency to think they understand the world in more detail, coherence, and depth than they actually do. Abstract thinking was reported as a reason for the IOED, and according to the social distance theory of power, power increases abstract thinking. We linked these literatures and tested construal style as a mediator. Further, predispositions can moderate effects of power and we considered narcissism as a candidate because narcissism leads to overconfidence and may thus increase the IOED especially in combination with high power. In three preregistered studies (total N = 607), we manipulated power or measured feelings of power. We found evidence for the IOED (regarding explanatory knowledge about devices). Power led to general overconfidence but had only a small impact on the IOED. Power and narcissism had a small interactive effect on the IOED. Meta-analytical techniques suggest that previous findings on the construal-style-IOED link show only weak evidential value. Implications refer to research on management, power, and overconfidence., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Körner et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Increasing evidence suggests that secondary sclerosing cholangitis (SSC), which can lead to cirrhosis or liver failure, may be a hepatobiliary long-term complication of COVID-19. The aim of this study was to estimate the frequency and outcome of this COVID-19 sequela and to identify possible risk factors., Methods: This observational study, conducted at University Hospital Charité Berlin and Unfallkrankenhaus Berlin, Germany, involved hospitalized patients with COVID-19 pneumonia, including 1082 ventilated COVID-19 patients. We compared COVID-19 patients who developed SSC with a COVID-19 control group by univariate and multivariate analyses., Results: SSC occurrence after COVID-19 was observed exclusively in critically ill patients with invasive ventilation, albeit with extreme clustering among them. One in every 43 invasively ventilated COVID-19 patients developed this complication. Risk factors preceding the development of secondary sclerosing cholangitis in critically ill COVID-19 patients (SSC-CIP) were signs of systemic reduced blood oxygen supply (e.g., low PaO 2 /FiO 2 , ischemic organ infarctions), multi-organ failure (high SOFA score) at admission, high fibrinogen levels and intravenous ketamine use. Multivariate analysis confirmed fibrinogen and increased plasma lactate dehydrogenase as independent risk factors associated with cholangiopathy onset. The 1-year transplant-free survival rate of COVID-19-associated SSC-CIP was 40%., Conclusions: COVID-19 causes SSC-CIP in a substantial proportion of critically ill patients. SSC-CIP most likely develops due to severe tissue hypoxia and fibrinogen-associated circulatory disturbances. A significant increase of patients with SSC-CIP is to be expected in the post-COVID era., (© 2023. The Author(s).)

Two basic strategies can be applied to navigate hierarchies: (a) dominance , which involves the induction of fear, intimidation, or coercion to obtain status, or (b) prestige , which involves using one's skills, knowledge, or expertise to pursue status. In the present research, we refined the original dominance and prestige account and the respective self-report scale and conceptualized and assessed both variables as stable self-concept facets. By doing so, we extended the explanatory power of the model. Four studies (total N  = 1,993) showed good psychometric properties for the newly developed dominance and prestige questionnaire (DPQ). Both dominance and prestige showed high temporal stability. In testing associations with 72 personality variables and 14 objective criteria, nomological and criterion validity were supported. For the first time, the concepts were shown to predict friendship satisfaction. Further, in testing a truth and bias model, we found high self-other agreement for both self-concept facets. Thus, self-perceptions of dominance and prestige proved to be stable, valid, accurate, and relevant in contexts beyond leadership. Future research concerning the self-perception of these concepts could test the relevance of dominance and prestige in additional spheres of life (e.g. families, academia).

Background: Self-tracking - the collection, storage, analysis, and evaluation of self-related data (e.g., on one's diet, fitness activities, sports performance, or finances) - is a recent and widespread trend. Less is known about who engages in self-tracking. We expected perfectionism to be linked to self-tracking because performance optimization is central to this activity., Participants and Procedure: A German convenience sample ( N = 145; 64% women, mean age = 32 years) was recruited for this cross-sectional study. The sample comprised a mix of students and community participants. Participants completed an online questionnaire with scales on self-tracking (Self Quantification Scale), perfectionism (Multidimensional Perfectionism Scale with subscales striving for achievement and evaluative concerns), and personality (Big Five Inventory-10)., Results: Using a two-dimensional conceptualization of perfectionism and controlling for the Big Five, we found that striving for achievement was strongly positively related to self-tracking, whereas evaluative concerns was not significantly linked. Apparently, people who set high goals and want to meet high standards are more likely than others to engage in self-tracking. However, people's engagement in self-tracking was independent of their personality., Conclusions: The results point to the importance of distinguishing between different perfectionism dimensions in relation to self-tracking. Future research could explore additional performance-related traits (e.g., grit) to expand the understanding of self-tracking., Competing Interests: The authors declare no conflict of interest., (Copyright © Institute of Psychology, University of Gdansk.)

Amyloid-like aggregates of the microtubule-associated protein Tau are associated with several neurodegenerative disorders including Alzheimer's disease. The existence of cellular machinery for the removal of such aggregates has remained unclear, as specialized disaggregase chaperones are thought to be absent in mammalian cells. Here we show in cell culture and in neurons that the hexameric ATPase valosin-containing protein (VCP) is recruited to ubiquitylated Tau fibrils, resulting in their efficient disaggregation. Aggregate clearance depends on the functional cooperation of VCP with heat shock 70 kDa protein (Hsp70) and the ubiquitin-proteasome machinery. While inhibition of VCP activity stabilizes large Tau aggregates, disaggregation by VCP generates seeding-active Tau species as byproduct. These findings identify VCP as a core component of the machinery for the removal of neurodegenerative disease aggregates and suggest that its activity can be associated with enhanced aggregate spreading in tauopathies., (© 2023. The Author(s).)

We offer a critical perspective on the meta-analysis by Elkjær et al. (2020) by pointing out three constraints: The first refers to open-science practices, the second addresses the selection of studies, and the third offers a broader theoretical perspective. We argue that preregistration and adherence to the highest standards of conducting meta-analyses is important. Further, we identified several missing studies. Regarding the theoretical perspective, we suggest that it may be useful to tie body positions into the dominance-prestige framework and, on that basis, to distinguish two types of body positions. Such an approach has the potential to account for discrepancies in previous meta-analytical evidence regarding the effects of expansive versus contractive nonverbal displays. Future research may thus be able to provide not only methodological but also theoretical innovations to the field of body positions.

Drugs intoxications often lead to severe vasoplegia and cardiogenic shock, and VA-ECMO represents a viable therapy option. However, as cardiopulmonary support is not contributing to the removal of the causal agent from the blood, detoxification by a new hemoadsorption device (CytoSorb) could represent a potential therapeutic tool due to its highly efficient elimination capacity of endogenous but also exogenous hydrophobic substances for which otherwise no effective antidote exist. In this case series, four anecdotal cases of acute intoxications requiring VA-ECMO support used as extracorporeal cardiopulmonary resuscitation after intoxication-induced out-of-hospital cardiac arrest (OHCA) are presented, who were additionally treated with CytoSorb hemoadsorption in combination with renal replacement therapy. Combined treatment was associated with a considerable decrease in plasma levels of the overdosed drugs. Additionally, the combination of applied techniques was safe, practical, and technically feasible with no adverse or any device-related side effects documented during or after the treatment sessions. Based on the reported dramatic decline in drug levels during treatment, that fits in the device's characteristics, we strongly suggest to further investigate the potentially lifesaving role of CytoSorb therapy in patients with acute intoxications requiring multiple organ support techniques., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2021.)

Introduction: Acute kidney injury (AKI) is an important complication in COVID-19, but its precise etiology has not fully been elucidated. Insights into AKI mechanisms may be provided by analyzing the temporal associations of clinical parameters reflecting disease processes and AKI development., Methods: We performed an observational cohort study of 223 consecutive COVID-19 patients treated at 3 sites of a tertiary care referral center to describe the evolvement of severe AKI (Kidney Disease: Improving Global Outcomes stage 3) and identify conditions promoting its development. Descriptive statistics and explanatory multivariable Cox regression modeling with clinical parameters as time-varying covariates were used to identify risk factors of severe AKI., Results: Severe AKI developed in 70 of 223 patients (31%) with COVID-19, of which 95.7% required kidney replacement therapy. Patients with severe AKI were older, predominantly male, had more comorbidities, and displayed excess mortality. Severe AKI occurred exclusively in intensive care unit patients, and 97.3% of the patients developing severe AKI had respiratory failure. Mechanical ventilation, vasopressor therapy, and inflammatory markers (serum procalcitonin levels and leucocyte count) were independent time-varying risk factors of severe AKI. Increasing inflammatory markers displayed a close temporal association with the development of severe AKI. Sensitivity analysis on risk factors of AKI stage 2 and 3 combined confirmed these findings., Conclusion: Severe AKI in COVID-19 was tightly coupled with critical illness and systemic inflammation and was not observed in milder disease courses. These findings suggest that traditional systemic AKI mechanisms rather than kidney-specific processes contribute to severe AKI in COVID-19., (© 2021 International Society of Nephrology. Published by Elsevier Inc.)

The HSP60/HSP10 chaperonin assists folding of proteins in the mitochondrial matrix space by enclosing them in its central cavity. The chaperonin forms part of the mitochondrial protein quality control system. It is essential for cellular survival and mutations in its subunits are associated with rare neurological disorders. Here we present the first survey of interactors of the human mitochondrial HSP60/HSP10 chaperonin. Using a protocol involving metabolic labeling of HEK293 cells, cross-linking, and immunoprecipitation of HSP60, we identified 323 interacting proteins. As expected, the vast majority of these proteins are localized to the mitochondrial matrix space. We find that approximately half of the proteins annotated as mitochondrial matrix proteins interact with the HSP60/HSP10 chaperonin. They cover a broad spectrum of functions and metabolic pathways including the mitochondrial protein synthesis apparatus, the respiratory chain, and mitochondrial protein quality control. Many of the genes encoding HSP60 interactors are annotated as disease genes. There is a correlation between relative cellular abundance and relative abundance in the HSP60 immunoprecipitates. Nineteen abundant matrix proteins occupy more than 60% of the HSP60/HSP10 chaperonin capacity. The reported inventory of interactors can form the basis for interrogating which proteins are especially dependent on the chaperonin.

Stress-inducible molecular chaperones have essential roles in maintaining protein homeostasis, but the extent to which they affect overall proteome stability remains unclear. Here, we analyze the effects of the DnaK (Hsp70) system on protein stability in Escherichia coli using pulse proteolysis combined with quantitative proteomics. We quantify ∼1,500 soluble proteins and find ∼500 of these to be protease sensitive under normal growth conditions, indicating a high prevalence of conformationally dynamic proteins, forming a metastable subproteome. Acute heat stress results in the unfolding of an additional ∼200 proteins, reflected in the exposure of otherwise buried hydrophobic regions. Overexpression of the DnaK chaperone system markedly stabilizes numerous thermo-sensitive proteins, including multiple ribosomal proteins and large, hetero-oligomeric proteins containing the evolutionarily ancient c.37 fold (P loop nucleoside triphosphate hydrolases). Thus, the Hsp70 system, in addition to its known chaperone functions, has a remarkable capacity to stabilize proteins in their folded states under denaturing stress conditions., (Crown Copyright © 2019. Published by Elsevier Inc. All rights reserved.)

The nuclear proteome is rich in stress-sensitive proteins, which suggests that effective protein quality control mechanisms are in place to ensure conformational maintenance. We investigated the role of the nucleolus in this process. In mammalian tissue culture cells under stress conditions, misfolded proteins entered the granular component (GC) phase of the nucleolus. Transient associations with nucleolar proteins such as NPM1 conferred low mobility to misfolded proteins within the liquid-like GC phase, avoiding irreversible aggregation. Refolding and extraction of proteins from the nucleolus during recovery from stress was Hsp70-dependent. The capacity of the nucleolus to store misfolded proteins was limited, and prolonged stress led to a transition of the nucleolar matrix from liquid-like to solid, with loss of reversibility and dysfunction in quality control. Thus, we suggest that the nucleolus has chaperone-like properties and can promote nuclear protein maintenance under stress., (Copyright © 2019, American Association for the Advancement of Science.)

Eukaryotic elongation factor 2 (eEF2) is an abundant and essential component of the translation machinery. The biogenesis of this 93 kDa multi-domain protein is assisted by the chaperonin TRiC/CCT. Here, we show in yeast cells that the highly conserved protein Hgh1 (FAM203 in humans) is a chaperone that cooperates with TRiC in eEF2 folding. In the absence of Hgh1, a substantial fraction of newly synthesized eEF2 is degraded or aggregates. We solved the crystal structure of Hgh1 and analyzed the interaction of wild-type and mutant Hgh1 with eEF2. These experiments revealed that Hgh1 is an armadillo repeat protein that binds to the dynamic central domain III of eEF2 via a bipartite interface. Hgh1 binding recruits TRiC to the C-terminal eEF2 module and prevents unproductive interactions of domain III, allowing efficient folding of the N-terminal GTPase module. eEF2 folding is completed upon dissociation of TRiC and Hgh1., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Amino acid analysis is among the most accurate methods for absolute quantification of proteins and peptides. Here we combine acid hydrolysis with the addition of isotopically labeled standard amino acids and analysis by mass spectrometry for accurate and sensitive protein quantitation. Quantitation of less than 10 fmol of protein standards with errors below 10% has been demonstrated using this method.

Protein aggregation is associated with neurodegeneration and various other pathologies. How specific cellular environments modulate the aggregation of disease proteins is not well understood. Here, we investigated how the endoplasmic reticulum (ER) quality control system handles β-sheet proteins that were designed de novo to form amyloid-like fibrils. While these proteins undergo toxic aggregation in the cytosol, we find that targeting them to the ER (ER-β) strongly reduces their toxicity. ER-β is retained within the ER in a soluble, polymeric state, despite reaching very high concentrations exceeding those of ER-resident molecular chaperones. ER-β is not removed by ER-associated degradation (ERAD) but interferes with ERAD of other proteins. These findings demonstrate a remarkable capacity of the ER to prevent the formation of insoluble β-aggregates and the secretion of potentially toxic protein species. Our results also suggest a generic mechanism by which proteins with exposed β-sheet structure in the ER interfere with proteostasis., (© 2017 The Authors.)

Background : More and more people of all age classes have a tattoo. Intriguingly, there are multiple prejudices in the general population and published data that concern tattooed persons, such as being criminals, having a low education, being alcohol or drug abusers, or more risky in their life style. Objective : To obtain and to evaluate sociodemographic data on tattooed persons, to investigate the incidence of tattoo-related cutaneous complications and to define personal risk factors and course of the persons after being tattooed concerning behavior of personal environment. Patients and Methods : We interviewed 426 participants with already existing tattoos and 20 participants just before getting a new tattoo by using an online questionnaire. The participators were asked about socio-epidemiologic aspects of tattoos in general and special aspects of their own tattoo(s) in particular. There were no exclusion criteria. Results : Tattoos are interesting for people seeking popular body art, esp. university graduates and financially-secure individuals. 446 persons participated in this study. Most of the persons were female with a mean age of 35. Local pruritus around the tattooed area was the most common cutaneous side effect among the participants. 93.5% of the participants did not want a tattoo removal. Intriguingly, most of the participants experienced no career problems related to the tattoo(s). Limitations : The study population is not representative as we included only persons being tattooed prior to or getting newly tattooed. Furthermore, there is a potential selection bias as the participation in this study was voluntary. Only persons that felt involved by the flyer did answer the questionnaire. Conclusion : The present data shows that common tattooed persons are not low educated criminals with any drug or alcohol abuse or with risky life style. Nowadays being tattooed encompasses a kind of body art and displays a certain kind of lifestyle habit.

The cellular release of membranous vesicles known as extracellular vesicles (EVs) or exosomes represents a novel mode of intercellular communication. Eph receptor tyrosine kinases and their membrane-tethered ephrin ligands have very important roles in such biologically diverse processes as neuronal development, plasticity, and pathological diseases. Until now, it was thought that ephrin-Eph signaling requires direct cell contact. Although the biological functions of ephrin-Eph signaling are well understood, our mechanistic understanding remains modest. Here we report the release of EVs containing Ephs and ephrins by different cell types, a process requiring endosomal sorting complex required for transport (ESCRT) activity and regulated by neuronal activity. Treatment of cells with purified EphB2(+) EVs induces ephrinB1 reverse signaling and causes neuronal axon repulsion. These results indicate a novel mechanism of ephrin-Eph signaling independent of direct cell contact and proteolytic cleavage and suggest the participation of EphB2(+) EVs in neural development and synapse physiology., (© 2016 Gong et al.)

The ToxCast EPA challenge was managed by TopCoder in Spring 2014. The goal of the challenge was to develop a model to predict the lowest effect level (LEL) concentration based on in vitro measurements and calculated in silico descriptors. This article summarizes the computational steps used to develop the Rank-I model, which calculated the lowest prediction error for the secret test data set of the challenge. The model was developed using the publicly available Online CHEmical database and Modeling environment (OCHEM), and it is freely available at http://ochem.eu/article/68104 . Surprisingly, this model does not use any in vitro measurements. The logic of the decision steps used to develop the model and the reason to skip inclusion of in vitro measurements is described. We also show that inclusion of in vitro assays would not improve the accuracy of the model.

Translation of messenger RNAs lacking a stop codon results in the addition of a carboxy-terminal poly-lysine tract to the nascent polypeptide, causing ribosome stalling. Non-stop proteins and other stalled nascent chains are recognized by the ribosome quality control (RQC) machinery and targeted for proteasomal degradation. Failure of this process leads to neurodegeneration by unknown mechanisms. Here we show that deletion of the E3 ubiquitin ligase Ltn1p in yeast, a key RQC component, causes stalled proteins to form detergent-resistant aggregates and inclusions. Aggregation is dependent on a C-terminal alanine/threonine tail that is added to stalled polypeptides by the RQC component, Rqc2p. Formation of inclusions additionally requires the poly-lysine tract present in non-stop proteins. The aggregates sequester multiple cytosolic chaperones and thereby interfere with general protein quality control pathways. These findings can explain the proteotoxicity of ribosome-stalled polypeptides and demonstrate the essential role of the RQC in maintaining proteostasis.

The use of long-term animal studies for human and environmental toxicity estimation is more discouraged than ever before. Alternative models for toxicity prediction, including QSAR studies, are gaining more ground. A recent approach is to combine in vitro chemical profiling and in silico chemical descriptors with the knowledge about toxicity pathways to derive a unique signature for toxicity endpoints. In this study we investigate the ToxCast™ Phase I data regarding their ability to predict long-term animal toxicity. We investigated thousands of models constructed in an effort to predict 61 toxicity endpoints using multiple descriptor packages and hundreds of in vitro assays. We investigated the use of in vitro assays and biochemical pathways on model performance. We identified 10 toxicity endpoints where biologically derived descriptors from in vitro assays or pathway perturbations improved the model prediction ability. In vivo toxicity endpoints proved generally challenging to model. Few models were possible to readily model with a balanced accuracy (BA) above 0.7. We also constructed in silico models to predict the outcome of 144 in vitro assays. This showed better statistical metrics with 79 out of 144 assays having median balanced accuracy above 0.7. This suggests that the in vitro datasets have a better modelability than in vivo animal toxicities for the given datasets. Moreover, we published an online platform (http://iprior.ochem.eu) that automates large-scale model building and analysis.

Expansion of a poly-glutamine (polyQ) repeat in a group of functionally unrelated proteins is the cause of several inherited neurodegenerative disorders, including Huntington's disease. The polyQ length-dependent aggregation and toxicity of these disease proteins can be reproduced in Saccharomyces cerevisiae. This system allowed us to screen for genes that when overexpressed reduce the toxic effects of an N-terminal fragment of mutant huntingtin with 103 Q. Surprisingly, among the identified suppressors were three proteins with Q-rich, prion-like domains (PrDs): glycine threonine serine repeat protein (Gts1p), nuclear polyadenylated RNA-binding protein 3, and minichromosome maintenance protein 1. Overexpression of the PrD of Gts1p, containing an imperfect 28 residue glutamine-alanine repeat, was sufficient for suppression of toxicity. Association with this discontinuous polyQ domain did not prevent 103Q aggregation, but altered the physical properties of the aggregates, most likely early in the assembly pathway, as reflected in their increased SDS solubility. Molecular simulations suggested that Gts1p arrests the aggregation of polyQ molecules at the level of nonfibrillar species, acting as a cap that destabilizes intermediates on path to form large fibrils. Quantitative proteomic analysis of polyQ interactors showed that expression of Gts1p reduced the interaction between polyQ and other prion-like proteins, and enhanced the association of molecular chaperones with the aggregates. These findings demonstrate that short, Q-rich peptides are able to shield the interactive surfaces of toxic forms of polyQ proteins and direct them into nontoxic aggregates.

Background: QSAR is an established and powerful method for cheap in silico assessment of physicochemical properties and biological activities of chemical compounds. However, QSAR models are rather complex mathematical constructs that cannot easily be interpreted. Medicinal chemists would benefit from practical guidance regarding which molecules to synthesize. Another possible approach is analysis of pairs of very similar molecules, so-called matched molecular pairs (MMPs). Such an approach allows identification of molecular transformations that affect particular activities (e.g. toxicity). In contrast to QSAR, chemical interpretation of these transformations is straightforward. Furthermore, such transformations can give medicinal chemists useful hints for the hit-to-lead optimization process., Results: The current study suggests a combination of QSAR and MMP approaches by finding MMP transformations based on QSAR predictions for large chemical datasets. The study shows that such an approach, referred to as prediction-driven MMP analysis, is a useful tool for medicinal chemists, allowing identification of large numbers of "interesting" transformations that can be used to drive the molecular optimization process. All the methodological developments have been implemented as software products available online as part of OCHEM (http://ochem.eu/)., Conclusions: The prediction-driven MMPs methodology was exemplified by two use cases: modelling of aquatic toxicity and CYP3A4 inhibition. This approach helped us to interpret QSAR models and allowed identification of a number of "significant" molecular transformations that affect the desired properties. This can facilitate drug design as a part of molecular optimization process. Graphical AbstractMolecular matched pairs and transformation graphs facilitate interpretable molecular optimisation process.

To present and define diagnostic criteria for primary cutaneous carcinosarcomas (CSs). Neoplasms of 6 patients with primary cutaneous CSs were retrospectively analyzed. A panel of histopathologic parameters and immunophenotypic expression of distinct markers of differentiation were investigated. All cases had medium-to-poorly differentiated squamous cell carcinoma representing the epithelial component intermingled with a variable amount of malignant sarcomatous tissue proliferation. The authors identified 3 distinct morphological criteria for the diagnosis of primary cutaneous CSs with features of (1) a clearly defined dual neoplasm with explicit morphological characterization using histology and immunohistochemistry with distinct marker panels while, (2) metastases from distant sites and true collision neoplasms must be excluded, and (3) recognition of the neoplasm as a solid coherent proliferation with careful exclusion of sarcomatous stromal changes in the surrounding neoplasm stroma has to be assured. The low incidence of this entity and a plethora of different synonymous terms in the dermatopathologic literature often cause diagnostic problems and hamper the accurate comparative analysis of cases published previously. Herein, the authors propose defining criteria and a clearly defined morphological approach to contribute to more accurate dermatopathologic diagnoses and provide an unprecedented summary on this neoplastic entity.

When exposed to proteotoxic environmental conditions, mammalian cells activate the cytosolic stress response in order to restore protein homeostasis. A key feature of this response is the heat shock transcription factor 1 (HSF1)-dependent expression of molecular chaperones. Here, we describe the results of an RNA interference screen in HeLa cells to identify modulators of stress response induction and attenuation. The modulator proteins are localized in multiple cellular compartments, with chromatin modifiers and nuclear protein quality control playing a central regulatory role. We find that the acetyltransferase, EP300, controls the cellular level of activatable HSF1. This involves acetylation of HSF1 at multiple lysines not required for function and results in stabilization of HSF1 against proteasomal turnover. Acetylation of functionally critical lysines during stress serves to fine-tune HSF1 activation. Finally, the nuclear proteasome system functions in attenuating the stress response by degrading activated HSF1 in a manner linked with the clearance of misfolded proteins., (Copyright © 2014 Elsevier Inc. All rights reserved.)

GeSn (Sn content up to 4.2%) photodiodes with vertical pin structures were grown on thin Ge virtual substrates on Si by a low temperature (160 °C) molecular beam epitaxy. Vertical detectors were fabricated by a double mesa process with mesa radii between 5 µm and 80 µm. The nominal intrinsic absorber contains carrier densities from below 1 · 10(16) cm(-3) to 1 · 10(17) cm(-3) for Ge reference detectors and GeSn detectors with 4.2% Sn, respectively. The photodetectors were investigated with electrical and optoelectrical methods from direct current up to high frequencies (40 GHz). For a laser wavelength of 1550 nm an increasing of the optical responsivities (84 mA/W -218 mA/W) for vertical incidence detectors with thin (300 nm) absorbers as function of the Sn content were found. Most important from an application perspective all detectors had bandwidth above 40 GHz at enough reverse voltage which increased from zero to -5 V within the given Sn range. Increasing carrier densities (up to 1 · 10(17) cm(-3)) with Sn contents caused the depletion of the nominal intrinsic absorber at increasing reverse voltages.

Background and Objectives: With the number of tattoos increasing, a rising number of complications have also been reported, such as allergic and foreign body reactions or the development of malignant tumors. We discuss 19 patients with alterations in skin tattoos, define clinicopathologic characteristics and give a brief review of the literature., Patients and Methods: Biopsy specimens were obtained in 13 of 19 patients. In all cases, staining was performed with hematoxylin-eosin, periodic acid-Schiff, CD68, CD123, and CD163. The inflammatory infiltrate was classified according to the pattern analysis of Ackerman., Results: Three of 19 patients (15.8%) had temporary tattoos with henna and 16 (84.2%) had permanent tattoos. Histologically, among the 13 biopsy specimens we found signs of acute contact dermatitis in 2 (15.3%), lupus-like patterns in 2 (15.3%), foreign body dermatitis in 5 (38.4%), deposition of pigment without inflammation or simple scarring in 2 (15.3%), and tumors in 2 patients (15.2%), 1 of which was a malignant melanoma., Conclusions: Clinical presentation frequently, but not always, correlates with the histologic pattern. Obtaining a biopsy can be helpful in determining further investigations, for example allergy testing or a search for systemic involvement in cases of tattoo sarcoidosis., (© The Authors | Journal compilation © Blackwell Verlag GmbH, Berlin.)

Background: The role of maspin has been discussed controversially in different tumors. In the majority of malignant tumors, maspin seems to act as a tumor suppressor. However, data about maspin expression as well as its function in melanoma are very inconsistent., Objective: To investigate the expression of maspin in melanomas and to correlate the intensity of maspin staining with prognostic parameters of the tumor and with progression-free and overall survival., Patients and Methods: Primary melanomas from 47 patients were investigated for maspin expression using immunohistochemistry., Results: Maspin was heterogeneously expressed predominantly in the cytoplasm of melanoma cells. Maspin staining intensity in the invasive part of the tumor correlated with parameters of prognosis such as Clark level (p  =  0.05), tumor thickness (p  =  0.002) and stage of disease (p  =  0.023). Maspin staining intensity in the invasive front of the tumor significantly correlated with death from disease (p  =  0.007) and shortened overall survival (p  =  0.007)., Conclusions: In accordance with data concerning maspin expression in colorectal cancers, the expression of this protein in the invasive front of primary melanomas seems to correlate with local infiltration and tumor aggressiveness. Strong maspin expression in the invasive margin of primary melanomas therefore might reflect an aggressive tumor phenotype., (© The Authors | Journal compilation © Blackwell Verlag GmbH, Berlin.)

Maternal Embryonic Leucine zipper Kinase (MELK) was recently shown to be involved in cell division of Xenopus embryo epithelial cells. The cytokinetic furrow of these cells ingresses asymmetrically and is developmentally regulated. Two subpopulations of xMELK, the mMELK (for "mitotic" xMELK) and iMELK ("interphase" xMELK), which differ in their spatial and temporal regulation, are detected in Xenopus embryo. How cells regulate these two xMELK populations is unknown. In this study we show that, in epithelial cells, xMELK is present at a higher concentration at the apical junctional complex, in contrast to mesenchyme-like cells, which have uniform distribution of cortical MELK. Interestingly, mMELK and iMELK also differ by their requirements towards cell-cell contacts to establish their proper cortical localization both in epithelial and mesenchyme-like cells. Receptor for Activated protein Kinase C (RACK1), which we identified as an xMELK partner, co-localizes with xMELK at the tight junction. Moreover, a truncated RACK1 construct interferes with iMELK localization at cell-cell contacts. Collectively, our results suggest that iMELK and RACK1 are present in the same complex and that RACK1 is involved in the specific recruitment of iMELK at the apical junctional complex in epithelial cells of Xenopus embryos.

Background: The incidence of skin tumors is increasing among elderly patients, and the multi-morbidities which occur in the elderly are a great challenge for dermatologic surgeons. The currently required safety margins for different types of melanomas and non-melanoma skin cancers lead to extensive and profound wounds., Objective: To investigate the usefulness of a dermal substitute (Integra®) for routine use in surgery for dermatologic tumors., Patients and Methods: In this retrospective study 20 patients underwent sequential surgeries for skin cancer. Wound closures were performed using Integra® (single layer) and immediate split-thickness skin graft., Results: Twenty-two tumors (6 malignant melanomas, 10 squamous cell carcinomas, 2 pleomorphic sarcomas, 1 basal cell carcinoma, 2 Merkel cell carcinomas, and 1 trichoblastic carcinoma) were resected. The mean defect size was 41.4 cm(2) . All transplants were (65-100 %) vital; however, defects in the midface (cheek and infra-orbital area) often healed with esthetically disturbing, dense, pillow-like scars., Conclusions: With the use of Integra®, the duration of hospitalization was decreased, patients with multi-morbidities were effectively treated, and functionally- and esthetically-satisfactory outcomes were achieved. On the basis of these observations, we discuss points of handling those patients who require rapid and effective surgery and undergo dermatologic surgery using dermal substitutes., (© The Authors • Journal compilation © Blackwell Verlag GmbH, Berlin.)

Background: Autoantibodies against CD28 have been found in patients with autoimmune and atopic diseases. These antibodies may act as superagonists and activate T cells but may also be antagonistic or induce immunosuppressive effects by activating regulatory T cells. Autoimmunity in melanoma patients has been discussed controversially., Objective: We investigated 230 melanoma patients for the occurrence of CD28 antibodies and the effect of the latter on overall and progress-free survival., Methods: We constructed an ELISA assay to measure CD28 serum antibodies. 230 patients with melanoma and a control-group of 625 patients consistent of 212 patients with virus hepatitis b or c, 149 patients with allergies, 78 patients with psoriasis, 46 patients with plasmocytoma and 140 healthy blood donors were investigated for the occurrence of CD28 antibodies., Results: CD28 abs occur at a higher percentage in patients with melanoma and in patients with viral hepatitis than in other groups investigated (p<0.001). Occurrence of CD28 abs is significantly higher in patients receiving interferons independent from the underlying disease (p<0.001). In vitro CD28 serum antibodies have an inhibitory effect on the CD28 receptor as they lead to reduced stimulation of Jurkat cells. Presence of CD28 was correlated with a higher risk of dying from melanoma (p = 0.043), but not with a significantly shortened overall survival or progression-free survival., Conclusion: Interferon therapy appears to induce the production of CD28 abs. In light of reports that these CD28 abs induce immunosuppressive Tregs and - as our data show - that they are inhibitors of CD28 receptor mediated stimulation, the continuation of therapies with interferons in melanoma patients developing CD28 antibodies should be critically reconsidered, since our data indicate a worse outcome of patients with CD28 abs.

Only a few cases of contact allergic gastritis in patients with nickel allergy have been reported. We report a case of probable contact-allergic gastritis in a 46-year-old woman. Clinical examination revealed lichenoid mucosal lesions of the gums adjacent to bridges and crowns that had been implanted several weeks back. Since implantation, the patient had suffered from gastrointestinal complaints (including stomach pain). Gastroscopy showed eosinophilic gastritis. Patch testing done under the diagnosis of contact allergic stomatitis showed positive reactions to: gold sodium thiosulphate; manganese (II) chloride; nickel (II) sulphate; palladium chloride; vanadium (III) chloride and zirconium (IV) chloride. The crowns and bridge contained gold, palladium and zirconium chloride, hence they were replaced by titan-based dentition. Shortly after replacing the artificial dentition, all gastrointestinal symptoms resolved spontaneously without further treatment. Delayed-type allergy against the components of artificial dentition seemed to be the cause of gastritis.

Proteasomes execute the degradation of most cellular proteins. Although the 20S core particle (CP) has been studied in great detail, the structure of the 19S regulatory particle (RP), which prepares ubiquitylated substrates for degradation, has remained elusive. Here, we report the crystal structure of one of the RP subunits, Rpn6, and we describe its integration into the cryo-EM density map of the 26S holocomplex at 9.1 Å resolution. Rpn6 consists of an α-solenoid-like fold and a proteasome COP9/signalosome eIF3 (PCI) module in a right-handed suprahelical configuration. Highly conserved surface areas of Rpn6 interact with the conserved surfaces of the Pre8 (alpha2) and Rpt6 subunits from the alpha and ATPase rings, respectively. The structure suggests that Rpn6 has a pivotal role in stabilizing the otherwise weak interaction between the CP and the RP.

Amino acid analysis is among the most accurate methods for absolute quantification of proteins and peptides. Here, we combine acid hydrolysis with the addition of isotopically labeled standard amino acids and analysis by mass spectrometry for accurate and sensitive protein quantitation. Quantitation of less than 10 fmol of protein standards with errors below 10% has been demonstrated using this method.

The mitotic spindle is an essential molecular machine involved in cell division, whose composition has been studied extensively by detailed cellular biology, high-throughput proteomics, and RNA interference experiments. However, because of its dynamic organization and complex regulation it is difficult to obtain a complete description of its molecular composition. We have implemented an integrated computational approach to characterize novel human spindle components and have analysed in detail the individual candidates predicted to be spindle proteins, as well as the network of predicted relations connecting known and putative spindle proteins. The subsequent experimental validation of a number of predicted novel proteins confirmed not only their association with the spindle apparatus but also their role in mitosis. We found that 75% of our tested proteins are localizing to the spindle apparatus compared to a success rate of 35% when expert knowledge alone was used. We compare our results to the previously published MitoCheck study and see that our approach does validate some findings by this consortium. Further, we predict so-called "hidden spindle hub", proteins whose network of interactions is still poorly characterised by experimental means and which are thought to influence the functionality of the mitotic spindle on a large scale. Our analyses suggest that we are still far from knowing the complete repertoire of functionally important components of the human spindle network. Combining integrated bio-computational approaches and single gene experimental follow-ups could be key to exploring the still hidden regions of the human spindle system.

Introduction: Breast cancer is common in women and its metastases involve the skin in approximately one quarter of patients. Accordingly, metastatic breast cancer shown to be cutaneous through histology must be distinguished from a wide variety of other neoplasms as well as the diverse morphologic variants of breast cancer itself., Case Presentation: We report the case of a 61-year-old Caucasian woman with cutaneous metastases of a bilateral ductal breast carcinoma that in histopathological examination mimicked an adnexal neoplasm with sebaceous differentiation., Conclusion: Against the background of metastatic breast carcinoma, dermatopathological considerations of sebaceous differentiation of skin lesions are presented and discussed focusing on the rare differential diagnosis of sebaceous carcinoma of the breast.

Prediction of CYP450 inhibition activity of small molecules poses an important task due to high risk of drug-drug interactions. CYP1A2 is an important member of CYP450 superfamily and accounts for 15% of total CYP450 presence in human liver. This article compares 80 in-silico QSAR models that were created by following the same procedure with different combinations of descriptors and machine learning methods. The training and test sets consist of 3745 and 3741 inhibitors and noninhibitors from PubChem BioAssay database. A heterogeneous external test set of 160 inhibitors was collected from literature. The studied descriptor sets involve E-state, Dragon and ISIDA SMF descriptors. Machine learning methods involve Associative Neural Networks (ASNN), K Nearest Neighbors (kNN), Random Tree (RT), C4.5 Tree (J48), and Support Vector Machines (SVM). The influence of descriptor selection on model accuracy was studied. The benefits of "bagging" modeling approach were shown. Applicability domain approach was successfully applied in this study and ways of increasing model accuracy through use of applicability domain measures were demonstrated as well as fragment-based model interpretation was performed. The most accurate models in this study achieved values of 83% and 68% correctly classified instances on the internal and external test sets, respectively. The applicability domain approach allowed increasing the prediction accuracy to 90% for 78% of the internal and 17% of the external test sets, respectively. The most accurate models are available online at http://ochem.eu/models/Q5747 .

The Online Chemical Modeling Environment is a web-based platform that aims to automate and simplify the typical steps required for QSAR modeling. The platform consists of two major subsystems: the database of experimental measurements and the modeling framework. A user-contributed database contains a set of tools for easy input, search and modification of thousands of records. The OCHEM database is based on the wiki principle and focuses primarily on the quality and verifiability of the data. The database is tightly integrated with the modeling framework, which supports all the steps required to create a predictive model: data search, calculation and selection of a vast variety of molecular descriptors, application of machine learning methods, validation, analysis of the model and assessment of the applicability domain. As compared to other similar systems, OCHEM is not intended to re-implement the existing tools or models but rather to invite the original authors to contribute their results, make them publicly available, share them with other users and to become members of the growing research community. Our intention is to make OCHEM a widely used platform to perform the QSPR/QSAR studies online and share it with other users on the Web. The ultimate goal of OCHEM is collecting all possible chemoinformatics tools within one simple, reliable and user-friendly resource. The OCHEM is free for web users and it is available online at http://www.ochem.eu.

The biopharmaceutical profile of a compound depends directly on the dissociation constants of its acidic and basic groups, commonly expressed as the negative decadic logarithm pKa of the acid dissociation constant (Ka). We survey the literature on computational methods to predict the pKa of small molecules. In this, we address data availability (used data sets, data quality, proprietary versus public data), molecular representations (quantum mechanics, descriptors, structured representations), prediction methods (approaches, implementations), as well as pKa-specific issues such as mono- and multiprotic compounds. We discuss advantages, problems, recent progress, and challenges in the field.

Background: Members of the Mps1 kinase family play an essential and evolutionarily conserved role in the spindle assembly checkpoint (SAC), a surveillance mechanism that ensures accurate chromosome segregation during mitosis. Human Mps1 (hMps1) is highly phosphorylated during mitosis and many phosphorylation sites have been identified. However, the upstream kinases responsible for these phosphorylations are not presently known., Methodology/principal Findings: Here, we identify 29 in vivo phosphorylation sites in hMps1. While in vivo analyses indicate that Aurora B and hMps1 activity are required for mitotic hyper-phosphorylation of hMps1, in vitro kinase assays show that Cdk1, MAPK, Plk1 and hMps1 itself can directly phosphorylate hMps1. Although Aurora B poorly phosphorylates hMps1 in vitro, it positively regulates the localization of Mps1 to kinetochores in vivo. Most importantly, quantitative mass spectrometry analysis demonstrates that at least 12 sites within hMps1 can be attributed to autophosphorylation. Remarkably, these hMps1 autophosphorylation sites closely resemble the consensus motif of Plk1, demonstrating that these two mitotic kinases share a similar substrate consensus., Conclusions/significance: hMps1 kinase is regulated by Aurora B kinase and its autophosphorylation. Analysis on hMps1 autophosphorylation sites demonstrates that hMps1 has a substrate preference similar to Plk1 kinase.

Argonaute (Ago) proteins are highly conserved between species and constitute a direct-binding platform for small RNAs including short-interfering RNAs (siRNAs), microRNAs (miRNAs) and Piwi interacting RNAs (piRNAs). Small RNAs function as guides whereas Ago proteins are the actual mediators of gene silencing. Although the major steps in RNA-guided gene silencing have been elucidated, not much is known about Ago-protein regulation. Here we report a comprehensive analysis of Ago2 phosphorylation in human cells. We find that the highly conserved tyrosine Y529, located in the small RNA 5'-end-binding pocket of Ago proteins can be phosphorylated. By substituting Y529 with a negatively charged glutamate (E) mimicking a phosphorylated tyrosine, we show that small RNA binding is strongly reduced. Our data suggest that a negatively charged phospho-tyrosine generates a repulsive force that prevents efficient binding of the negatively charged 5' phosphate of the small RNA.

Polo-like kinases regulate many aspects of mitotic and meiotic progression from yeast to man. In early mitosis, mammalian Polo-like kinase 1 (Plk1) controls centrosome maturation, spindle assembly, and microtubule attachment to kinetochores. However, despite the essential and diverse functions of Plk1, the full range of Plk1 substrates remains to be explored. To investigate the Plk1-dependent phosphoproteome of the human mitotic spindle, we combined stable isotope labeling by amino acids in cell culture with Plk1 inactivation or depletion followed by spindle isolation and mass spectrometry. Our study identified 358 unique Plk1-dependent phosphorylation sites on spindle proteins, including novel substrates, illustrating the complexity of the Plk1-dependent signaling network. Over 100 sites were validated by in vitro phosphorylation of peptide arrays, resulting in a broadening of the Plk1 consensus motif. Collectively, our data provide a rich source of information on Plk1-dependent phosphorylation, Plk1 docking to substrates, the influence of phosphorylation on protein localization, and the functional interaction between Plk1 and Aurora A on the early mitotic spindle.