88 research outputs found

    HBP-enhancing hepatocellular adenomas and how to discriminate them from FNH in Gd-EOB MRI

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    BackgroundRecent studies provide evidence that hepatocellular adenomas (HCAs) frequently take up gadoxetic acid (Gd-EOB) during the hepatobiliary phase (HBP). The purpose of our study was to investigate how to differentiate between Gd-EOB-enhancing HCAs and focal nodular hyperplasias (FNHs). We therefore retrospectively included 40 HCAs classified as HBP Gd-EOB-enhancing lesions from a sample of 100 histopathologically proven HCAs in 65 patients. These enhancing HCAs were matched retrospectively with 28 FNH lesions (standard of reference: surgical resection). Two readers (experienced abdominal radiologists blinded to clinical data) reviewed the images evaluating morphologic features and subjectively scoring Gd-EOB uptake (25-50%, 50-75% and 75-100%) for each lesion. Quantitative lesion-to-liver enhancement was measured in arterial, portal venous (PV), transitional and HBP. Additionally, multivariate regression analyses were performed. ResultsSubjective scoring of intralesional Gd-EOB uptake showed the highest discriminatory accuracies (AUC: 0.848 (R#1); 0.920 (R#2)-p0.05). ConclusionEven in HBP-enhancing HCA, characterization of Gd-EOB uptake was found to provide the strongest discriminatory power in differentiating HCA from FNH. Furthermore, a lobulated appearance and a central scar are more frequently seen in FNH than in HCA

    Автоматический выпуск конструкторской документации в PDM-системе

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    BaFe12O19 powders were prepared by coprecipitation and by glass crystallization. Electron microscopic investigations revealed that the particles of the glass crystallized powder exhibit excellent uniform shapes and narrow size distribution in comparison to the coprecipitated one consisting of irregularly shaped, polycrystalline particles with a broad and inhomogeneous size distribution. The crystallites of the coprecipitated powder particles, however, are smaller (mean diameter D = 0.11 μm) and the size distribution is narrower than that of the particles of the glass crystallized powder with a mean diameter of D = 0.42 μm. The lattice perfection of the particles and the crystallites of both ensembles is quite good. In order to determine the magnetic properties - above all the effective anisotropy field - we used six different methods: transverse susceptibility χt, singular point detection (SPD), ferromagnetic resonance (FMR), torsion pendulum (TP), rotational hysteresis losses (RHL), remanence curves (RC). It has been found that differences in coercivity values HcJ are not dramatic (about ±3%). Effective anisotropy fields Ha measured with “switching” methods (RHL, RC) are smaller than those measured with “stiffness” ones (FMR, TP, SPD, χt), by about 1700 Oe for the coprecipitated powder and about 2500 Oe for the glass crystallized one. The glass crystallized particle assemblies used for the present investigations do not exhibit pure Stoner-Wohlfarth behaviour, because of their relatively large particle diameters. The ratio HcJ/Ha ≈ 0.39 of the coprecipitated powder is relatively near the ideal value of 0.48, although the particles are considerably mechanically aggregated. © 1992

    Obesity as risk factor for subtypes of breast cancer: results from a prospective cohort study

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    Background: Earlier epidemiological studies indicate that associations between obesity and breast cancer risk may not only depend on menopausal status and use of exogenous hormones, but might also differ by tumor subtype. Here, we evaluated whether obesity is differentially associated with the risk of breast tumor subtypes, as defined by 6 immunohistochemical markers (ER, PR, HER2, Ki67, Bcl-2 and p53, separately and combined), in the prospective EPIC-Germany Study (n = 27,012). Methods: Formalin-fixed and paraffin-embedded (FFPE) tumor tissues of 657 incident breast cancer cases were used for histopathological analyses. Associations between BMI and breast cancer risk across subtypes were evaluated by multivariable Cox regression models stratified by menopausal status and hormone therapy (HT) use. Results: Among postmenopausal non-users of HT, higher BMI was significantly associated with an increased risk of less aggressive, i.e. ER+, PR+, HER2-, Ki67low, Bcl-2+ and p53- tumors (HR per 5 kg/m2: 1.44 [1.10, 1.90], p = 0.009), but not with risk of more aggressive tumor subtypes. Among postmenopausal users of HT, BMI was significantly inversely associated with less aggressive tumors (HR per 5 kg/m2: 0.68 [0.50, 0.94], p = 0.018). Finally, among pre- and perimenopausal women, Cox regression models did not reveal significant linear associations between BMI and risk of any tumor subtype, although analyses by BMI tertiles showed a significantly lower risk of less aggressive tumors for women in the highest tertile (HR: 0.55 [0.33, 0.93]). Conclusion: Overall, our results suggest that obesity is related to risk of breast tumors with lower aggressiveness, a finding that requires replication in larger-scale analyses of pooled prospective data

    Superconducting undulator activities at the European X-ray Free-Electron Laser Facility

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    For more than 5 years, superconducting undulators (SCUs) have been successfully delivering X-rays in storage rings. The European X-Ray Free-Electron Laser Facility (XFEL) plans to demonstrate the operation of SCUs in X-ray free-electron lasers (FELs). For the same geometry, SCUs can reach a higher peak field on the axis with respect to all other available technologies, offering a larger photon energy tunability range. The application of short-period SCUs in a high electron beam energy FEL > 11 GeV will enable lasing at very hard X-rays > 40 keV. The large tunability range of SCUs will allow covering the complete photon energy range of the soft X-ray experiments at the European XFEL without changing electron beam energy, as currently needed with the installed permanent magnet undulators. For a possible continuous-wave (CW) upgrade under discussion at the European XFEL with a lower electron beam energy of approximately 7–8 GeV, SCUs can provide the same photon energy range as available at present with the permanent magnet undulators and electron energies. This paper will describe the potential of SCUs for X-ray FELs. In particular, it will focus on the different activities ongoing at the European XFEL and in collaboration with DESY to allow the implementation of SCUs in the European XFEL in the upcoming years

    Test-retest reliability and predictive validity of a juvenile guide dog behavior test

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    The ability to measure stable and consistent behavioral traits in dogs would facilitate selection and assessment of working dogs, such as guide dogs. Ideally, these measures should predict suitability for the working role from a young age. This study assessed test-retest reliability of a juvenile guide dog behavior test and predictive validity using qualification or withdrawal from guide dog training. Ninety-three guide dog puppies (52 female; 41 male) were tested at 5 (mean 4.78; ±0.73 SD) and 8 (mean 7.98; ±0.78 SD) months of age. The dogs were exposed to a sequence of 11 stimuli designed to assess the dogs’ reactions to meeting a stranger, obedience commands, body sensitivity, scavenging, and “animal” and human distractions. The behavior of dogs was digitally recorded and analyzed using an ethogram incorporating both frequency of behavior and specific reactions to stimuli. Test-retest reliability indicated interindividual consistency in many of the behavioral measures such as jumping, barking, and “low” greeting posture, as defined in our ethogram. Behavior measures that did not show interindividual consistency between tests included obedience responses, lip licking, body shaking, and scratching. Binary logistic regression models revealed 7 behavioral measures at 5 months and 5 measures at 8 months that were significantly associated with qualification or withdrawal. Uncorrelated measures and principal component scores of correlated measures were combined in a logistic regression model that showed great potential for predicting the probability of a dog qualifying or being withdrawn from guide dog training

    Highly variable response to cytotoxic chemotherapy in carcinoma-associated fibroblasts (CAFs) from lung and breast

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    <p>Abstract</p> <p>Background</p> <p>Carcinoma-associated fibroblasts (CAFs) can promote carcinogenesis and tumor progression. Only limited data on the response of CAFs to chemotherapy and their potential impact on therapy outcome are available. This study was undertaken to analyze the influence of chemotherapy on carcinoma-associated fibroblasts (CAFs) <it>in vitro </it>and <it>in vivo</it>.</p> <p>Methods</p> <p>The <it>in vivo </it>response of stromal cells to chemotherapy was investigated in 22 neoadjuvant treated breast tumors on tissue sections before and after chemotherapy. Response to chemotherapy was analyzed <it>in vitro </it>in primary cultures of isolated CAFs from 28 human lung and 9 breast cancer tissues. The response was correlated to <it>Mdm2</it>, <it>ERCC1 </it>and <it>TP53 </it>polymorphisms and <it>TP53 </it>mutation status. Additionally, the cytotoxic effects were evaluated in an <it>ex vivo </it>experiment using cultured tissue slices from 16 lung and 17 breast cancer specimens.</p> <p>Results</p> <p>Nine of 22 tumors showed a therapy-dependent reduction of stromal activity. Pathological response of tumor or stroma cells did not correlate with clinical response. Isolated CAFs showed little sensitivity to paclitaxel. In contrast, sensitivity of CAFs to cisplatinum was highly variable with a GI50 ranging from 2.8 to 29.0 μM which is comparable to the range observed in tumor cell lines. No somatic <it>TP53 </it>mutation was detected in any of the 28 CAFs from lung cancer tissue. In addition, response to cisplatinum was not significantly associated with the genotype of <it>TP53 </it>nor <it>Mdm2 </it>and <it>ERCC1 </it>polymorphisms. However, we observed a non-significant trend towards decreased sensitivity in the presence of <it>TP53 </it>variant genotype. In contrast to the results obtained in isolated cell culture, in tissue slice culture breast cancer CAFs responded to paclitaxel within their microenvironment in the majority of cases (9/14). The opposite was observed in lung cancer tissues: only few CAFs were sensitive to cisplatinum within their microenvironment (2/15) whereas a higher proportion responded to cisplatinum in isolated culture.</p> <p>Conclusion</p> <p>Similar to cancer cells, CAF response to chemotherapy is highly variable. Beside significant individual/intrinsic differences the sensitivity of CAFs seems to depend also on the cancer type as well as the microenvironment.</p

    Redox dysregulation, neuroinflammation, and NMDA receptor hypofunction: A "central hub" in schizophrenia pathophysiology?

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    Accumulating evidence points to altered GABAergic parvalbumin-expressing interneurons and impaired myelin/axonal integrity in schizophrenia. Both findings could be due to abnormal neurodevelopmental trajectories, affecting local neuronal networks and long-range synchrony and leading to cognitive deficits. In this review, we present data from animal models demonstrating that redox dysregulation, neuroinflammation and/or NMDAR hypofunction (as observed in patients) impairs the normal development of both parvalbumin interneurons and oligodendrocytes. These observations suggest that a dysregulation of the redox, neuroimmune, and glutamatergic systems due to genetic and early-life environmental risk factors could contribute to the anomalies of parvalbumin interneurons and white matter in schizophrenia, ultimately impacting cognition, social competence, and affective behavior via abnormal function of micro- and macrocircuits. Moreover, we propose that the redox, neuroimmune, and glutamatergic systems form a "central hub" where an imbalance within any of these "hub" systems leads to similar anomalies of parvalbumin interneurons and oligodendrocytes due to the tight and reciprocal interactions that exist among these systems. A combination of vulnerabilities for a dysregulation within more than one of these systems may be particularly deleterious. For these reasons, molecules, such as N-acetylcysteine, that possess antioxidant and anti-inflammatory properties and can also regulate glutamatergic transmission are promising tools for prevention in ultra-high risk patients or for early intervention therapy during the first stages of the disease
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