julilili42/papers huggingface dataset:
β-Catenin as a multilayer modulator of zonal cytochrome P450 expression in mouse liver
2009-12-23

Abstract The liver is the major organ for metabolism of drugs and other xenobiotics. Expression of many drug-metabolizing enzymes is not equally distributed throughout the liver: under normal conditions, many of them, including the most relevant members of the cytochrome P450 superfamily, are exclusively expressed in a hepatocyte subpopulation located near branches of the efferent central vein. Activation of different ligand-dependent transcription factors by exogenous compounds stimulates high expression of certain cytochrome P450 isoforms. This process also occurs preferentially in perivenous hepatocytes. The mechanisms, however, which determine the zone-specificity of basal and xenobiotic-induced expression of cytochrome P450 enzymes, have remained largely unknown for decades. Very recently, signaling through the Wnt/β-catenin pathway has been implicated in the regulation of zonal gene expression in mouse liver. In this review, current knowledge of cytochrome P450 regulation by β-catenin-dependent transcription is summarized and underlying molecular mechanisms are discussed.
Dendritic cells are susceptible to infection with wild-type adenovirus, inducing a differentiation arrest in precursor cells and inducing a strong T-cell stimulation
2009-12-23

Adenovirus infection after stem cell transplantation is a significant cause of morbidity and mortality, especially in children. A robust T-cell response induced by dendritic cells (DC) is crucial for clearing the virus, suggesting their pivotal role for the response to human adenoviruses (HAdV). Despite the widespread use of adenoviral vectors, the properties and kinetics of HAdV infection of DC have not been addressed yet. We show that a recent clinical HAdV, subgenus C/serotype 2 (strain BB2000-61), infects cells of the myeloid lineage. Infected DC produce early and late viral antigens and show an altered expression of surface markers. Infection of monocytes renders them refractory to differentiation into DC. Additionally, HAdV-infected DC are strong stimulators of CD8+ T cells. In summary, HAdV seems to manipulate the immune response by infection of DC and possibly uses the infection of monocytes as a means to escape recognition by T cells.
Upgrading SELEX Technology by Using Lambda Exonuclease Digestion for Single-Stranded DNA Generation
2009-12-24

The generation of single-stranded DNA (ssDNA) molecules plays a key role in the SELEX (Systematic Evolution of Ligands by EXponential enrichment) combinatorial chemistry process and numerous molecular biology techniques and applications, such as DNA sequencing, single-nucleotide polymorphism (SNP) analysis, DNA chips, DNA single-strand conformation polymorphism (SSCP) analysis and many other techniques. The purity and yield of ssDNA can affect the success of each application. This study compares the two ssDNA production methods, the strand separation by streptavidin-coated magnetic beads and alkaline denaturation and the lambda exonuclease digestion, in regard to the purity of generated ssDNA and the efficiency. Here, we demonstrate the considerable benefits of ssDNA production by lambda exonuclease digestion for in vitro selection of DNA aptamers. We believe that the generation of ssDNA aptamers using this method will greatly improve the success rate of SELEX experiments concerning the recovery of target-specific aptamers.
Crystallization and preliminary crystallographic analysis of the measles virus hemagglutinin in complex with the CD46 receptor
2009-12-24

The measles virus (MV) hemagglutinin (MV-H) mediates the attachment of MV particles to cell-surface receptors for entry into host cells. MV uses two receptors for attachment to host cells: the complement-control protein CD46 and the signalling lymphocyte activation molecule (SLAM). The MV-H glycoprotein from an Edmonston MV variant and the MV-binding fragment of the CD46 receptor were overproduced in mammalian cells and used to crystallize an MV-H-CD46 complex. Well diffracting crystals containing two complexes in the asymmetric unit were obtained and the structure of the complex was solved by the molecular-replacement method.
Extreme microstomia in an 8-month-old infant: bilateral commissuroplasty using rhomboid buccal mucosa flaps.
2009-12-26

We present our surgical technique, the postoperative functional and esthetic outcome, and a brief literature review. Only few publications deal with the same matter and none with a similar life-threatening case.
The Effects of COMT (Val108/158Met) and DRD4 (SNP -521) Dopamine Genotypes on Brain Activations Related to Valence and Magnitude of Rewards
2009-12-27

People's sensitivity to reinforcing stimuli such as monetary gains and losses shows a wide interindividual variation that might in part be determined by genetic differences. Because of the established role of the dopaminergic system in the neural encoding of rewards and negative events, we investigated young healthy volunteers being homozygous for either the Valine or Methionine variant of the catechol-O-methyltransferase (COMT) codon 158 polymorphism as well as homozygous for the C or T variant of the SNP -521 polymorphism of the dopamine D4 receptor. Participants took part in a gambling paradigm featuring unexpectedly high monetary gains and losses in addition to standard gains/losses of expected magnitude while undergoing functional magnetic resonance imaging at 3 T. Valence-related brain activations were seen in the ventral striatum, the anterior cingulate cortex, and the inferior parietal cortex. These activations were modulated by the COMT polymorphism with greater effects for valine/valine participants but not by the D4 receptor polymorphism. By contrast, magnitude-related effects in the anterior insula and the cingulate cortex were modulated by the D4 receptor polymorphism with larger responses for the CC variant. These findings emphasize the differential contribution of genetic variants in the dopaminergic system to various aspects of reward processing.
Analysis of the Liposidomycin Gene Cluster Leads to the Identification of New Caprazamycin Derivatives
2009-12-28

En route: The liposidomycin biosynthetic gene cluster has been identified, cloned and heterologously expressed. A comparison with the gene cluster of the structurally related caprazamycins supports the proposed pathway to liponucleoside formation and led to the identification of new sulfated caprazamycin derivatives. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Macroeconomic Shocks and Banks' Foreign Assets
2009-12-28

Recent developments in international financial markets have highlighted the role of banks in the transmission of shocks across borders. We employ dynamic panel methods for a sample of OECD countries to analyze whether banks' foreign assets react to macroeconomic shocks at home and abroad. We find that banks reduce their foreign assets in response to a relative increase in domestic interest rates, and they increase their foreign assets when the growth rate of world energy prices rises. The responses are characterized by a temporal overshooting and a dynamic adjustment process that extends over several quarters.
Local Anesthetic Effects on Human Neutrophil Priming and Activation
2009-12-28

The intracellular generation of reactive oxygen species remains largely unaffected by LAs in clinical concentrations. This suggests that the anti-inflammatory effects of LAs do not interfere with the host defense.
EFNS guidelines on the molecular diagnosis of ataxias and spastic paraplegias
2009-12-29

Background and purpose: These EFNS guidelines on the molecular diagnosis of neurogenetic disorders are designed to provide practical help for the general neurologist to make appropriate use of molecular genetics in diagnosing neurogenetic disorders. Methods: Literature searches were performed before expert members of the task force wrote proposals, which were discussed in detail until final consensus had been reached among all task force members. Results and conclusion: This paper provides updated guidelines for molecular diagnosis of two particularly complex groups of disorders, the ataxias and spastic paraplegias. Possibilities and limitations of molecular genetic diagnosis of these disorders are evaluated and recommendations are provided.
“Plastic Trash goes Biohybrid”—Rapid and Selective Functionalization of Inert Plastic Surfaces with Biomolecules
2009-12-29

Abstract The covalent functionalization of “inert” polymers such as polypropylene with biomolecules for biocompatible or biosensor surfaces is challenging. Here we present a powerful approach to covalently modify “inert” macromolecular surfaces with biomacromolecules reusing old plastic material. A special emphasis was placed on easily accessible materials and a process which is easy, fast, efficient, cheap, and reliable. “Plastic trash” (lids from Eppendorf® pipet tip containers) was used as a polymer substrate to demonstrate the use/reuse of commercial packing material to covalently modify this material with a thin reactive plasma polymerized maleic anhydride nanolayer network, which can be subsequently modified with biomolecules for various applications, e.g., in tissue engineering and as biochips. magnified image
Multiple Linear Panel Regression with Multiplicative Random Noise
2009-12-29

The paper explores the effect of multiplicative measurement errors on the estimation of a multiple linear panel data model. The conventional fixed effects estimator of the slope parameter vector,which ignores measurement errors, is biased. By correcting for the bias one can construct a consistent and asymptotically normal estimator. In addition, we find a consistent estimate of the asymptotic covariance matrix of this estimator. Measurement errors are sometimes deliberately added to the data in order to minimize their disclosure risk, and then it is often multiplicative errors that are used instead of the more conventional additive errors. Multiplicative errors can be analyzed in a similar way as additive errors, but with some important and consequential differences.
Crosslinguistic variation in comparison constructions
2009-12-31

This paper presents parallel sets of data on comparison constructions from 14 languages. On the basis of the crosslinguistic differences we observe, we propose three parameters of language variation. The first parameter concerns the question of whether or not a language’s grammar has incorporated scales into the meanings of gradable predicates. The second parameter differentiates between languages that allow quantification over degrees in the syntax and those that do not. Finally, we propose a syntactic parameter that concerns options for syntactically filling the degree argument position of a gradable predicate.
The influence of psychological state and motivation on brain-computer interface performance in patients with amyotrophic lateral sclerosis - a longitudinal study
2010-01-01

The current study investigated the effects of psychological well-being measured as quality of life (QoL), depression, current mood and motivation on brain-computer interface (BCI) performance in amyotrophic lateral sclerosis (ALS). Six participants with most advanced ALS were trained either for a block of 20 sessions with a BCI based on sensorimotor rhythms (SMR) or a block of 10 sessions with a BCI based on event-related potentials, or both. Questionnaires assessed QoL and severity of depressive symptoms before each training block and mood and motivation before each training session. The SMR-BCI required more training than the P300-BCI. The information transfer rate was higher with the P300-BCI (3.25 bits/min) than with the SMR-BCI (1.16 bits/min). Mood and motivation were related to the number of BCI sessions. Motivational factors, specifically challenge and mastery confidence, were positively related to BCI performance (controlled for the number of sessions) in tow participants, while incompetence fear was negatively related with performance in one participant. BCI performance was not related to motivational factors in three other participants nor to mood in any of the six participants. We conclude that motivational factors may be related to BCI performance in individual subjects and suggest that motivational factors and well-being should be assessed in standard BCI protocols. We also recommend using P300-based BCI as first choice in severely paralyzed patients who present with a P300 evoked potential.
Ceramide in Suicidal Death of Erythrocytes
2010-01-01

The suicidal death of erythrocytes or eryptosis is characterized by cell shrinkage, membrane blebbing and cell membrane phospholipid scrambling resulting in phosphatidylserine exposure at the cell surface. Eryptosis is stimulated in a wide variety of diseases including sepsis, haemolytic uremic syndrome, malaria, sickle-cell anemia, beta-thalassemia, glucose-6-phosphate dehydrogenase (G6PD)-deficiency, phosphate depletion, iron deficiency and Wilson's disease. Moreover, eryptosis is elicited by osmotic shock, oxidative stress, energy depletion as well as a wide variety of endogenous mediators and xenobiotics. Excessive eryptosis is observed in erythrocytes lacking the cGMP-dependent protein kinase type I (cGKI) or the AMP-activated protein kinase AMPK. Inhibitors of eryptosis include erythropoietin, nitric oxide NO, catecholamines and high concentrations of urea. Eryptosis-triggering diseases and chemicals are partially effective by stimulating the formation of ceramide, which in turn fosters cell membrane scrambling. Accordingly, ceramide-induced eryptosis participates in the pathophysiology of several diseases and contributes to the effects of a large number of xenobiotics. The mechanisms underlying ceramide formation in erythrocytes are, however, still ill defined. In case of osmotic cell shrinkage, ceramide formation is apparently due to activation of phospholipase 2, leading to formation of platelet activating factor PAF and PAF-dependent stimulation of ceramide formation, which possibly involves acid sphingomyelinase. Additional experiments are needed to conclusively define the ceramide-generating enzyme and the ceramide-dependent cellular events eventually leading to suicidal erythrocyte death.
The relation of ongoing brain activity, evoked neural responses, and cognition
2010-01-01

Ongoing brain activity has been observed since the earliest neurophysiological recordings and is found over a wide range of temporal and spatial scales. It is characterized by remarkably large spontaneous modulations. Here, we review evidence for the functional role of these ongoing activity fluctuations and argue that they constitute an essential property of the neural architecture underlying cognition. The role of spontaneous activity fluctuations is probably best understood when considering both their spatiotemporal structure and their functional impact on cognition. We first briefly argue against a "segregationist" view on ongoing activity, both in time and space, which would selectively associate certain frequency bands or levels of spatial organization with specific functional roles. Instead, we emphasize the functional importance of the full range, from differentiation to integration, of intrinsic activity within a hierarchical spatiotemporal structure. We then highlight the flexibility and context-sensitivity of intrinsic functional connectivity that suggest its involvement in functionally relevant information processing. This role in information processing is pursued by reviewing how ongoing brain activity interacts with afferent and efferent information exchange of the brain with its environment. We focus on the relationship between the variability of ongoing and evoked brain activity, and review recent reports that tie ongoing brain activity fluctuations to variability in human perception and behavior. Finally, these observations are discussed within the framework of the free-energy principle which - applied to human brain function - provides a theoretical account for a non-random, coordinated interaction of ongoing and evoked activity in perception and behavior.
Mechanisms and neural basis of object and pattern recognition: A study with chess experts.
2010-01-01

Comparing experts with novices offers unique insights into the functioning of cognition, based on the maximization of individual differences. Here we used this expertise approach to disentangle the mechanisms and neural basis behind two processes that contribute to everyday expertise: object and pattern recognition. We compared chess experts and novices performing chess-related and -unrelated (visual) search tasks. As expected, the superiority of experts was limited to the chess-specific task, as there were no differences in a control task that used the same chess stimuli but did not require chess-specific recognition. The analysis of eye movements showed that experts immediately and exclusively focused on the relevant aspects in the chess task, whereas novices also examined irrelevant aspects. With random chess positions, when pattern knowledge could not be used to guide perception, experts nevertheless maintained an advantage. Experts' superior domain-specific parafoveal vision, a consequence of their knowledge about individual domain-specific symbols, enabled improved object recognition. Functional magnetic resonance imaging corroborated this differentiation between object and pattern recognition and showed that chess-specific object recognition was accompanied by bilateral activation of the occipitotemporal junction, whereas chess-specific pattern recognition was related to bilateral activations in the middle part of the collateral sulci. Using the expertise approach together with carefully chosen controls and multiple dependent measures, we identified object and pattern recognition as two essential cognitive processes in expert visual cognition, which may also help to explain the mechanisms of everyday perception.
Brain Painting: First Evaluation of a New Brain–Computer Interface Application with ALS-Patients and Healthy Volunteers
2010-01-01

Brain-computer interfaces (BCIs) enable paralyzed patients to communicate; however, up to date, no creative expression was possible. The current study investigated the accuracy and user-friendliness of P300-Brain Painting, a new BCI application developed to paint pictures using brain activity only. Two different versions of the P300-Brain Painting application were tested: A colored matrix tested by a group of ALS-patients (n = 3) and healthy participants (n = 10), and a black and white matrix tested by healthy participants (n = 10). The three ALS-patients achieved high accuracies; two of them reaching above 89% accuracy. In healthy subjects, a comparison between the P300-Brain Painting application (colored matrix) and the P300-Spelling application revealed significantly lower accuracy and P300 amplitudes for the P300-Brain Painting application. This drop in accuracy and P300 amplitudes was not found when comparing the P300-Spelling application to an adapted, black and white matrix of the P300-Brain Painting application. By employing a black and white matrix, the accuracy of the P300-Brain Painting application was significantly enhanced and reached the accuracy of the P300-Spelling application. ALS-patients greatly enjoyed P300-Brain Painting and were able to use the application with the same accuracy as healthy subjects. P300-Brain Painting enables paralyzed patients to express themselves creatively and to participate in the prolific society through exhibitions.
Dermacozines, a new phenazine family from deep-sea dermacocci isolated from a Mariana Trench sediment
2010-01-01

Dermacoccus abyssi sp. nov., strains MT1.1 and MT1.2 are actinomycetes isolated from Mariana Trench sediment at a depth of 10 898 m. Fermentation using ISP2 and 410 media, respectively, lead to production of seven new oxidized and reduced phenazine-type pigments, dermacozines A-G (1-7), together with the known phenazine-1-carboxylic acid (8) and phenazine-1,6-dicarboxylic acid (9). Extensive use was made of 1D and 2D-NMR data, and high resolution MS to determine the structures of the compounds. To confirm the structure of the most complex pentacyclic analogue (5) we made use of electronic structure calculations to compare experimental and theoretical UV-Vis spectra, which confirmed a novel structural class of phenazine derivatives, the dermacozines. The absolute stereochemistry of dermacozine D (4) was determined as S by a combination of CD spectroscopy and electronic structure calculations. Dermacozines F (6) and G (7) exhibited moderate cytotoxic activity against leukaemia cell line K562 with IC(50) values of 9 and 7 microM, respectively, while the highest radical scavenger activity was observed for dermacozine C (3) with an IC(50) value of 8.4 microM.
Stimulation of Suicidal Erythrocyte Death by &alpha;-Lipoic Acid
2010-01-01

α-lipoic acid, a nutrient with both, antioxidant and oxidant activity induces apoptosis in a variety of cells. Owing to its proapoptotic potency α-lipoic acid has been suggested for the therapy of cancer. α-Lipoic acid stimulates apoptosis by induction of oxidative stress and subsequent activation of caspases. Oxidative stress could similarly trigger caspase activation and suicidal erythrocyte death or eryptosis, which is characterized by cell membrane scrambling and cell shrinkage. Eryptosis is triggered by increase of cytosolic Ca(2+) concentration and/or ceramide formation. The present study explored whether α -lipoic acid influences eryptosis. Cell membrane scrambling was estimated from binding of annexin V to phosphatidylserine at the erythrocyte surface, cell volume from forward scatter in FACS analysis, cytosolic Ca(2+) concentration from Fluo3 fluorescence, caspase activation and ceramide formation utilizing respective antibodies, cytosolic ATP concentration from a luciferase-assay. Within 48 hours, exposure to α-lipoic acid (10 - 75 mM) significantly decreased forward scatter, increased cytosolic Ca(2+) concentration, decreased ATP concentration, activated caspase 3, stimulated formation of ceramide and triggered annexin V-binding. Glucose depletion (48 h) was followed by decrease of forward scatter and increase of annexin V-binding, effects significantly augmented in the presence of α-lipoic acid (20 mM). Oxidative stress (30 min 0.3 mM tert-butylhydroperoxide) similarly triggered annexin binding, an effect slightly but significantly blunted by α-lipoic acid. In conclusion, α-lipoic acid triggers eryptosis but by the same token counteracts eryptosis during oxidative stress. α-lipoic acid sensitive eryptosis may lead to anemia and derangements of microcirculation.