julilili42/papers huggingface dataset:
Combined PET/MR Imaging — Technology and Applications
2010-02-01

The combination of PET and MR in one imaging device has certain advantages over conventional imaging modalities. These include: no additional radiation dose from the MR, superior soft tissue contrast and a multitude of tracers for PET. Certain technical challenges exist when designing a PET/MR system. On the one hand these stem from the presence of the strong MR magnetic field and the addition of PET components to the MR system. Different approaches are presented to overcome these technical obstacles ranging from long optical fibers to systems that use semiconductor light detectors for photon counting. The applications of combined PET/MR are profound in the field of oncology and allow imaging of the four main processes in cancer formation: apoptosis resistance, angiogenesis, proliferation and metastasis. PET/MR has also many clinical and research applications in neurology and cardiology. Alternative techniques such as image fusion, hyperpolarized imaging, 17 O imaging and whole body diffusion are discussed in respect to their relevance regarding PET/MR. Simultaneous multifunctional and anatomical imaging using PET/MR has a great potential to impact biomedical imaging in research and clinic.
Basal serum tryptase as risk assessment for severe Hymenoptera sting reactions in elderly
2010-02-01

To cite this article: Guenova E, Volz T, Eichner M, Hoetzenecker W, Caroli U, Griesinger G, Burow G, Mitev V, Biedermann T. Basal serum tryptase as risk assessment for severe Hymenoptera sting reactions in elderly. Allergy 2010; 65 : 919–923. Abstract Background: Epidemiologic studies suggest that elderly people are more prone to develop severe anaphylactic reactions. However, the exact cause for this phenomenon remains unclear. Aims of the study: To study the role of the serum tryptase as a diagnostic parameter for individual risk evaluation and its impact on the severity of allergic reactions in elderly people. Methods: Two hundred and seventy‐four consecutive patients visiting the Department of Dermatology, Tübingen, Germany, who were diagnosed with honeybee or wasp venom allergy, were included in the study. Results: Sting reaction severity increased with increased age and tryptase levels ( P = 0.001 and P = 0.0003, respectively). Furthermore, we find not only a general increment in tryptase levels in elderly people ( P = 0.0001) but also a continuous increase in tryptase concentrations even below the cut‐off (11.4 μg/l) with increasing age ( P = 0.0026). Conclusions: Our data confirm serum tryptase as a risk factor for severe anaphylactic reaction to hymenoptera stings. Furthermore, we give first evidence that basal serum tryptase levels increase continuously with age and being an indicator for either increased mast cell load or reactivity this can at least partly be responsible for the observed aggravated allergic reactions in elderly people. As those patients are at increased risk for life‐threatening anaphylactic reactions, it should be considered to adjust VIT especially in elderly patients with elevated tryptase levels as recommended for patients with mastocytosis by increasing venom doses during VIT and by considering its life‐long continuation.
Dendritic Cells (DCs) Can Be Successfully Generated From Leukemic Blasts in Individual Patients With AML or MDS
2010-02-01

Myeloid-leukemic cells (AML, MDS, CML) can be differentiated to leukemia-derived dendritic cell [DC (DCleu)] potentially presenting the whole leukemic antigen repertoire without knowledge of distinct leukemia antigens and are regarded as promising candidates for a vaccination strategy. We studied the capability of 6 serum-free DC culture methods, chosen according to different mechanisms, to induce DC differentiation in 137 cases of AML and 52 cases of MDS. DC-stimulating substances were cytokines ("standard-medium", "MCM-Mimic", "cytokine-method"), bacterial lysates ("Picibanil"), double-stranded RNA ["Poly (I:C)"] or a cytokine bypass method ("Ca-ionophore"). The quality/quantity of DC generated was estimated by flow cytometry studying (co) expressions of "DC"antigens, costimulatory, maturation, and blast-antigens. Comparing these methods on average 15% to 32% DC, depending on methods used, could be obtained from blast-containing mononuclear cells (MNC) in AML/MDS cases with a DC viability of more than 60%. In all, 39% to 64% of these DC were mature; 31% to 52% of leukemic blasts could be converted to DCleu and DCleu-proportions in the suspension were 2% to 70% (13%). Average results of all culture methods tested were comparable, however not every given case of AML could be differentiated to DC with 1 selected method. However performing a pre-analysis with 3 DC-generating methods (MCM-Mimic, Picibanil, Ca-ionophore) we could generate DC in any given case. Functional analyses provided proof, that DC primed T cells to antileukemia-directed cytotoxic cells, although an anti-leukemic reaction was not achieved in every case. In summary our data show that a successful, quantitative DC/DCleu generation is possible with the best of 3 previously tested methods in any given case. Reasons for different functional behaviors of DC-primed T cells must be evaluated to design a practicable DC-based vaccination strategy.
Thermal evolution of the Malá Fatra Mountains (Central Western Carpathians): insights from zircon and apatite fission track thermochronology
2010-02-01

Thermal evolution of the Malá Fatra Mountains (Central Western Carpathians): insights from zircon and apatite fission track thermochronology We apply zircon and apatite fission track thermochronology (ZFT and AFT, respectively) to the Variscan crystal-line basement of the Malá Fatra Mts (Central Western Carpathians) in order to constrain the thermal history. The samples yielded three Early Cretaceous ZFT ages (143.7±9.6, 143.7±8.3, 135.3±6.9 Ma) and one Eocene age (45.2±2.1 Ma), proving that the basement was affected by a very low-grade Alpine metamorphic overprint. Although the precise timing and mechanisms of the overprint cannot be unequivocally resolved, we propose and discuss three alternative explanations: (i) a Jurassic/Cretaceous thermal event related to elevated heat flow associated with extensional tectonics, (ii) early Late Cretaceous thrusting and/or (iii) an Eocene orogeny. Thermal modelling of the AFT cooling ages (13.8±1.4 to 9.6±0.6 Ma) revealed fast cooling through the apatite partial annealing zone. The cooling is interpreted in terms of exhumation of the basement and creation of topographic relief, as corroborated by the sedimentary record in the surrounding Neogene depressions. Our AFT results significantly refine a general exhumation pattern of basement complexes in the Central Western Carpathians. A younging of AFT ages towards the orogenic front is evident, where all the external massifs located closest to the orogenic front (including Malá Fatra Mts) were exhumed after ~13 Ma from temperatures above ~120 °C.
Ionic Conductivity of Ce3NF6
2010-02-01

Abstract The electrical conductivity of pressed polycrystalline Ce 3 NF 6 pellets was measured using two‐probe measurements with two types of blocking contacts, namely platinum and LaF 3 , in the temperature range 300–450 K. The cerium nitride fluoride Ce 3 NF 6 was prepared by the direct reaction of CeN and CeF 3 at 1170 K. The DC measurements with the two types of blocking contacts proved that the conductivity of Ce 3 NF 6 is mainly ionic due to fluoride ion transport, although the fluoride ion conductivity is much lower than known for the binary CeF 3 phase. The analysis of the AC impedance measurements with both types of blocking contacts support the assumption of predominating fluoride ion transport. There was no indication for mobile nitride ions. Two relaxation processes were identified in the impedance spectra giving two maxima of the phase angle. The first one occurred at high frequencies around 200 kHz and was attributed to the bulk conductivity and dielectric response of Ce 3 NF 6 . The second relaxation process showed the maximum of the phase angle at medium frequencies in the range 100 Hz to 10 kHz. It was attributed to the impedance of high resistivity contacts between the grains. The transference number of electrons was lower than 0.1. The fluoride ion conductivity at 450 K was 5 × 10 –7 S · cm –1 in the bulk and 7 × 10 –9 S · cm –1 in the grain boundaries. The corresponding activation energy from the temperature dependence of the conductivity was 0.6 eV with no discernible difference of bulk and grain boundary contribution.
Protein–protein‐interactions in a multiplexed, miniaturized format a functional analysis of Rho GTPase activation and inhibition
2010-02-01

Abstract A miniaturized, bead‐based protein–protein‐interaction assay was developed to study the interaction of Rho GTPases with regulatory proteins. The setup, which uses only minute amounts of sample, was used to analyze small molecules that inhibit the interaction between Rho GTPases and RhoGDIα. Prenylcysteine analogues and the replacement of GDP by non‐hydrolysable GTP analogues prevented the formation of Rho GTPase‐RhoGDIα complexes in a concentration‐dependent manner.
Processing of pictorial food stimuli in patients with eating disorders—A systematic review
2010-02-02

Abstract Objective: The processing of food cues in eating‐disordered patients has recently been increasingly investigated. Outlined is current evidence from pictorial food stimuli studies. Method: PubMed and PsychINFO were searched for quantitative pictorial food stimuli studies investigating healthy controls and expert‐diagnosed eating‐disordered patients. Results: Patients with eating disorders (ED) demonstrated cue reactivity to food stimuli. Results from functional imaging suggest sensory disengagement and higher emotional involvement while self‐reported data and facial EMG revealed that food pictures were perceived as less pleasurable. Different experimental paradigms have demonstrated an attentional bias for food cues in ED. Currently, psychophysiological data is widely inconclusive. Discussion: Evidence suggests cue reactivity to food pictures in eating‐disordered patients. However, the overall picture is inconclusive because methodological problems and the integration of findings from different experimental approaches pose a challenge to the research field. © 2010 by Wiley Periodicals, Inc.
Serum Response Factor Regulates Hippocampal Lamination and Dendrite Development and Is Connected with Reelin Signaling
2010-02-02

During brain development, neurons and their nerve fibers are often segregated in specific layers. The hippocampus is a well-suited model system to study lamination in health and aberrant cell/fiber lamination associated with neurological disorders. SRF (serum response factor), a transcription factor, regulates synaptic-activity-induced immediate-early gene (IEG) induction and cytoskeleton-based neuronal motility. Using early postnatal conditional SRF ablation, we uncovered distorted hippocampal lamination, including malpositioning of granule cell neurons and disruption of layer-restricted termination of commissural-associational and mossy fiber axons. Besides axons, dendrite branching and spine morphogenesis in Srf mutants were impaired, offering a first morphological basis for SRF's reported role in learning and memory. Srf mutants resemble mice lacking components of the reelin signaling cascade, a fundamental signaling entity in brain lamination. Our data indicate that reelin signaling and SRF-mediated gene transcription might be connected: reelin induces IEG and cytoskeletal genes in an SRF-dependent manner. Further, reelin-induced neurite motility is blocked in Srf mutants and constitutively active SRF rescues impaired neurite extension in reeler mouse mutants in vitro. In sum, data provided in this report show that SRF contributes to hippocampal layer and nerve fiber organization and point at a link between Srf gene transcription and reelin signaling.
Regulation of calcium signaling in dendritic cells by 1,25‐dihydroxyvitamin D 3
2010-02-02

Dendritic cells (DCs) are antigen‐presenting cells that provide a link between innate and adaptive immunity. Ca 2+ ‐dependent signaling plays a central regulatory role in DC responses to diverse antigens. DCs are a primary target of 1,25‐dihydroxyvitamin D 3 [1,25(OH) 2 D 3 ], a secosteroid hormone, that, in addition to its wellestablished action on Ca 2+ homeostasis, possesses immunomodulatory properties. Surprisingly, nothing is known about its effects on DC cytosolic Ca 2+ activity. The present study explored whether 1,25(OH) 2 D 3 modifies the intracellular Ca 2+ concentration ([Ca 2+ ] i ) in DCs. Here we show that mouse DCs expressed K + ‐independent (NCX1–3) and K + ‐dependent (NCKX1, 3, 4, and 5) Na + /Ca 2+ exchangers. Acute application of LPS (100 ng/ml) to DCs increased [Ca 2+ ] i , an effect significantly blunted by prior incubation with 1,25(OH) 2 D 3 . 1,25(OH) 2 D 3 increased the membrane abundance of the NCKX1 protein, up‐regulated the K + ‐ and Na + ‐dependent Ca 2+ entry and enhanced the K + ‐dependent Na + /Ca 2+ exchanger currents. The NCKX blocker 3′,4′‐dichlorobenzamyl (DBZ) reversed the inhibitory effect of 1,25(OH) 2 D 3 on the LPS‐induced increase of [Ca 2+ ] i . Expression of the costimulatory molecule CD86 was down‐regulated by 1,25(OH) 2 D 3 , an effect reversed by DBZ. In summary, 1,25(OH) 2 D 3 blunts the LPS‐induced increase in [Ca 2+ ] i by stimulation of Na + /Ca 2+ exchangerdependent Ca 2+ extrusion, an effect that contributes to 1,25(OH) 2 D 3 ‐mediated immunosuppression. The results disclose completely novel mechanisms in the regulation of DC maturation and function.—Shumilina, E., Xuan, N. T., Matzner, N., Bhandaru, M., Zemtsova, I. M., Lang, F. Regulation of calcium signaling in dendritic cells by 1,25‐dihydroxyvitamin D 3 . FASEB J. 24, 1989–1996 (2010). www.fasebj.org
Nanoscale Spectroscopic Imaging of Organic Semiconductor Films by Plasmon-Polariton Coupling
2010-02-03

Tip-enhanced near-field optical images and correlated topographic images of an organic semiconductor film (diindenoperylene, DIP) on Si have been recorded with high optical contrast and high spatial resolution (17 nm) using a parabolic mirror with a high numerical aperture for tip illumination and signal collection. The DIP molecular domain boundaries being one to four molecular layers (1.5-6 nm) high are resolved topographically by a shear-force scanning tip and optically by simultaneously recording the 6x10{5} times enhanced photoluminescence (PL). The excitation is 4x10{4} times enhanced and the intrinsically weak PL-yield of the DIP-film is 15-fold enhanced by the tip. The Raman spectra indicate an upright orientation of the DIP molecules. The enhanced PL contrast results from the local film morphology via stronger coupling between the tip plasmon and the exciton-polariton in the DIP film.
Staphylococcal PknB as the First Prokaryotic Representative of the Proline-Directed Kinases
2010-02-03

In eukaryotic cell types, virtually all cellular processes are under control of proline-directed kinases and especially MAP kinases. Serine/threonine kinases in general were originally considered as a eukaryote-specific enzyme family. However, recent studies have revealed that orthologues of eukaryotic serine/threonine kinases exist in bacteria. Moreover, various pathogenic species, such as Yersinia and Mycobacterium, require serine/threonine kinases for successful invasion of human host cells. The substrates targeted by bacterial serine/threonine kinases have remained largely unknown. Here we report that the serine/threonine kinase PknB from the important pathogen Staphylococcus aureus is released into the external milieu, which opens up the possibility that PknB does not only phosphorylate bacterial proteins but also proteins of the human host. To identify possible human targets of purified PknB, we studied in vitro phosphorylation of peptide microarrays and detected 68 possible human targets for phosphorylation. These results show that PknB is a proline-directed kinase with MAP kinase-like enzymatic activity. As the potential cellular targets for PknB are involved in apoptosis, immune responses, transport, and metabolism, PknB secretion may help the bacterium to evade intracellular killing and facilitate its growth. In apparent agreement with this notion, phosphorylation of the host-cell response coordinating transcription factor ATF-2 by PknB was confirmed by mass spectrometry. Taken together, our results identify PknB as the first prokaryotic representative of the proline-directed kinase/MAP kinase family of enzymes.
Fast automatic path proposal computation for hepatic needle placement
2010-02-03

Percutaneous image-guided interventions, such as radiofrequency ablation (RFA), biopsy, seed implantation, and several types of drainage, employ needle shaped instruments which have to be inserted into the patient's body. Precise planning of needle placement is a key to a successful intervention. The planning of the access path has to be carried out with respect to a variety of criteria for all possible trajectories to the selected target. Since the planning is performed in 2D slices, it demands considerable experience and constitutes a significant mental task. To support the process of finding a suitable path for hepatic interventions, we propose a fast automatic method that computes a list of path proposals for a given target point inside the liver with respect to multiple criteria that affect safety and practicability. Prerequisites include segmentation masks of the liver, of all relevant risk structures and, depending on the kind of procedure, of the tumor. The path proposals are computed based on a weighted combination of cylindrical projections. Each projection represents one path criterion and is generated using the graphics hardware of the workstation. The list of path proposals is generated in less than one second. Hence, updates of the proposals upon changes of the target point and other relevant input parameters can be carried out interactively. The results of a preliminary evaluation indicate that the proposed paths are comparable to those chosen by experienced radiologists and therefore are suited to support planning in the clinical environment. Our implementation focuses on RFA and biopsy in the liver but may be adapted to other types of interventions.
Gravitational stability of simply rotating Myers-Perry black holes: Tensorial perturbations
2010-02-04

We study the stability of D &gt;= 7 asymptotically flat black holes rotating in a single two-plane against tensor-type gravitational perturbations. The extensive search of quasinormal modes for these black holes did not indicate any presence of growing modes, implying the stability of simply rotating Myers-Perry black holes against tensor-type perturbations.
ChemInform Abstract: Synthesis and Crystal Structure of a Bixbyite‐Type Solid Solution Zr0.43Er0.57O1.07N0.43.
2010-02-04

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Nucleophilic Aromatic Substitution with 2,3‐Dihydro‐1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene.
2010-02-04

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Relativistic constituent quark model with infrared confinement
2010-02-05

We refine the relativistic constituent quark model developed in our previous papers to include the confinement of quarks. It is done, first, by introducing the scale integration in the space of alpha-parameters, and, second, by cutting this scale integration on the upper limit which corresponds to an infrared cutoff. In this manner one removes all possible thresholds presented in the initial quark diagram. The cutoff parameter is taken to be the same for all physical processes. We adjust other model parameters by fitting the calculated quantities of the basic physical processes to available experimental data. As an application, we calculate the electromagnetic form factors of the pion and the transition form factors of the omega and eta Dalitz decays.
Insulin Signal Transduction in Normal Cells and its Role in Carcinogenesis
2010-02-05

Convincing epidemiological evidence exists for a causal relationship between increased risk of cancer development and progression and type 2 diabetes mellitus as well as obesity. Though the underlying mechanisms remain elusive, in light of the well-described mitogenic actions of insulin, hyperinsulinaemia in the presence of insulin resistance is probably a key factor. In this short review, an overview over the insulin signalling cascade is given paying special attention to the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI 3-K)/mammalian target of rapamycin (mTOR) pathways which are involved in protein synthesis and cell growth.
The BCR/ABL‐inhibitors imatinib, nilotinib and dasatinib differentially affect NK cell reactivity
2010-02-08

Abstract In chronic myeloid leukemia (CML), BCR/ABL‐mediated oncogenic signaling can be targeted with the BCR/ABL‐inhibitors Imatinib, Nilotinib and Dasatinib. However, these agents may also affect anti‐tumor immunity. Here, we analyzed the effects of the 3 BCR/ABL‐inhibitors on natural killer (NK) cell reactivity. Exposure of CML cells (K562, Meg‐01) to pharmacological concentrations of Imatinib, Nilotinib and Dasatinib diminished expression of ligands for the activating immunoreceptor NKG2D to a similar extent. This resulted in comparably reduced NK cell cytotoxicity and IFN‐γ production. When direct effects on NK cell responses to K562 and primary CML cells as well as activating cytokines were studied, Dasatinib was found to abrogate NK cytotoxicity and cytokine production. Nilotinib did not alter cytotoxicity but, at high levels, impaired NK cytokine production, while Imatinib had no direct influence on NK cell reactivity. Of note, Nilotinib, but not the other BCR/ABL‐inhibitors increased cell death within the preferentially cytokine‐secreting CD56 bright CD16 − NK cell subset, which may, at least in part, serve to explain the effect of Nilotinib on NK cytokine production. Analysis of NK cell signaling revealed that Dasatinib inhibited proximal signaling events leading to decreased phosphorylation of PI3K and ERK that are crucial for NK cell reactivity. Imatinib and Nilotinib, in contrast, showed no relevant effect on NK cell PI3K or ERK activity. In light of the potential role of NK cells in the immunesurveillance of residual leukemia and for future combinatory immunotherapeutic approaches, our data indicate that choice and dosing of the most suitable BCR/ABL‐inhibitor for a given patient require careful consideration.