195 research outputs found

    The nymph of Zyginella pulchra Löw, 1885: (Hemiptera, Cicadellidae, Typhlocybinae)

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    Das fünfte Larvenstadium von Zyginella pulchra Löw (Cicadellidae, Typhlocybinae) wird beschrieben und mit anderen Laubgehölze besiedelnden Typhlocybinae verglichen.The 5th instar nymph of Zyginella pulchra Löw (Cicadellidae, Typhlocybinae) is described and compared with other tree-associated typhlocybine species

    Expression of the Neuroblastoma-Associated ALK-F1174L Activating Mutation During Embryogenesis Impairs the Differentiation of Neural Crest Progenitors in Sympathetic Ganglia.

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    Neuroblastoma (NB) is an embryonal malignancy derived from the abnormal differentiation of the sympathetic nervous system. The Anaplastic Lymphoma Kinase (ALK) gene is frequently altered in NB, through copy number alterations and activating mutations, and represents a predisposition in NB-genesis when mutated. Our previously published data suggested that ALK activating mutations may impair the differentiation potential of neural crest (NC) progenitor cells. Here, we demonstrated that the expression of the endogenous ALK gene starts at E10.5 in the developing sympathetic ganglia (SG). To decipher the impact of deregulated ALK signaling during embryogenesis on the formation and differentiation of sympathetic neuroblasts, Sox10-Cre;LSL-ALK-F1174L embryos were produced to restrict the expression of the human ALK-F1174L transgene to migrating NC cells (NCCs). First, ALK-F1174L mediated an embryonic lethality at mid-gestation and an enlargement of SG with a disorganized architecture in Sox10-Cre;LSL-ALK-F1174L embryos at E10.5 and E11.5. Second, early sympathetic differentiation was severely impaired in Sox10-Cre;LSL-ALK-F1174L embryos. Indeed, their SG displayed a marked increase in the proportion of NCCs and a decrease of sympathetic neuroblasts at both embryonic stages. Third, neuronal and noradrenergic differentiations were blocked in Sox10-Cre;LSL-ALK-F1174L SG, as a reduced proportion of Phox2b <sup>+</sup> sympathoblasts expressed βIII-tubulin and almost none were Tyrosine Hydroxylase (TH) positive. Finally, at E10.5, ALK-F1174L mediated an important increase in the proliferation of Phox2b <sup>+</sup> progenitors, affecting the transient cell cycle exit observed in normal SG at this embryonic stage. Altogether, we report for the first time that the expression of the human ALK-F1174L mutation in NCCs during embryonic development profoundly disturbs early sympathetic progenitor differentiation, in addition to increasing their proliferation, both mechanisms being potential crucial events in NB oncogenesis

    Säume wirken sich positiv auf die Gliedertiere aus

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    Im Rahmen des Teilprojektes «Wirkung neu angelegter Säume auf die Laufkäfer- und Spinnenfauna» wurden die Auswirkungen der Säume auf die Bodenarthropoden, insbesondere Laufkäfer und Spinnen, untersucht. Im Klettgau (SH) und in Litzibuch (AG) wurden jeweils zwei Säume und als Vergleichselemente zwei Buntbrachen und zwei Wegrandstreifen herangezogen. Die ausgewählten Bioindikatoren Laufkäfer und Spinnen, sowie als Beifänge Wanzen und Zikaden, wurden mit Bodenfallen erfasst. An 12 Standorten konnten insgesamt 21’000 Laufkäfer aus 93 Arten, 11’000 Spinnen aus 100 Arten, 44 Wanzenarten mit 1’691 Individuen sowie 29 Zikadenarten mit 270 Individuen festgestellt werden. Im Vergleich mit den Buntbrachen und mit den Wegrandstreifen nahmen die Säume eine mittlere Stellung ein. Die Säume boten sowohl den für Brache typischen Arthropodenarten als auch Grünlandspezialisten einen Lebensraum an. Sie stellen eine wertvolle Ergänzung zu Buntbrachen und Wiesen dar. Ausserdem tragen sie somit zur Erhöhung und Erhaltung der Artenvielfalt von Laufkäfern, Bodenspinnen, Bodenwanzen sowie Zikaden in der Agrarlandschaft bei

    TWIST1 expression is associated with high-risk neuroblastoma and promotes primary and metastatic tumor growth.

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    The embryonic transcription factors TWIST1/2 are frequently overexpressed in cancer, acting as multifunctional oncogenes. Here we investigate their role in neuroblastoma (NB), a heterogeneous childhood malignancy ranging from spontaneous regression to dismal outcomes despite multimodal therapy. We first reveal the association of TWIST1 expression with poor survival and metastasis in primary NB, while TWIST2 correlates with good prognosis. Secondly, suppression of TWIST1 by CRISPR/Cas9 results in a reduction of tumor growth and metastasis colonization in immunocompromised mice. Moreover, TWIST1 knockout tumors display a less aggressive cellular morphology and a reduced disruption of the extracellular matrix (ECM) reticulin network. Additionally, we identify a TWIST1-mediated transcriptional program associated with dismal outcome in NB and involved in the control of pathways mainly linked to the signaling, migration, adhesion, the organization of the ECM, and the tumor cells versus tumor stroma crosstalk. Taken together, our findings confirm TWIST1 as promising therapeutic target in NB

    Potent neutralization by monoclonal human IgM against SARS-CoV-2 is impaired by class switch.

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    To investigate the class-dependent properties of anti-viral IgM antibodies, we use membrane antigen capture activated cell sorting to isolate spike-protein-specific B cells from donors recently infected with SARS-CoV-2, allowing production of recombinant antibodies. We isolate 20, spike-protein-specific antibodies of classes IgM, IgG, and IgA, none of which shows any antigen-independent binding to human cells. Two antibodies of class IgM mediate virus neutralization at picomolar concentrations, but this potency is lost following artificial switch to IgG. Although, as expected, the IgG versions of the antibodies appear to have lower avidity than their IgM parents, this is not sufficient to explain the loss of potency

    Distribution of Aspergillus Species and Prevalence of Azole Resistance in Respiratory Samples From Swiss Tertiary Care Hospitals

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    Among 400 Aspergillus species from respiratory samples in Switzerland, Aspergillus fumigatus was the most frequent species. Non-fumigatus Aspergillus spp were more prevalent among solid organ transplant recipients and after azole exposure. Azole resistance was detected in 4 A fumigatus isolates, 3 of them with the "environmental" mutation TR34_{34}/L98H in the cyp51A gene

    Avaliação do uso da morfometria como suporte para a elaboração de mapa pedológico na bacia do Ribeirão da Pedreira - DF.

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    ABSTRACT -This work applied a pedological mapping methodology, in the basin of Ribeirão da Pedreira ? DF, using the morfometric parameters in order to elaborate pedologic maps. The Digital Elevation Model (DEM) was made with 2 meters resolution. Derived from the DEM, were obtained morfometric parameters as: slope, contributing area and flow direction. The frequency histograms were made from slope and elevation in order to define the range of the classes of soils of the basin. The methodology showed good results, once it was able to distinguish the main classes of soils present in the study area.Na publicação: Adriana Reatto

    Frequency and Prognostic Impact of ALK Amplifications and Mutations in the European Neuroblastoma Study Group (SIOPEN) High-Risk Neuroblastoma Trial (HR-NBL1).

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    In neuroblastoma (NB), the ALK receptor tyrosine kinase can be constitutively activated through activating point mutations or genomic amplification. We studied ALK genetic alterations in high-risk (HR) patients on the HR-NBL1/SIOPEN trial to determine their frequency, correlation with clinical parameters, and prognostic impact. Diagnostic tumor samples were available from 1,092 HR-NBL1/SIOPEN patients to determine ALK amplification status (n = 330), ALK mutational profile (n = 191), or both (n = 571). Genomic ALK amplification (ALKa) was detected in 4.5% of cases (41 out of 901), all except one with MYCN amplification (MNA). ALKa was associated with a significantly poorer overall survival (OS) (5-year OS: ALKa [n = 41] 28% [95% CI, 15 to 42]; no-ALKa [n = 860] 51% [95% CI, 47 to 54], [P < .001]), particularly in cases with metastatic disease. ALK mutations (ALKm) were detected at a clonal level (> 20% mutated allele fraction) in 10% of cases (76 out of 762) and at a subclonal level (mutated allele fraction 0.1%-20%) in 3.9% of patients (30 out of 762), with a strong correlation between the presence of ALKm and MNA (P < .001). Among 571 cases with known ALKa and ALKm status, a statistically significant difference in OS was observed between cases with ALKa or clonal ALKm versus subclonal ALKm or no ALK alterations (5-year OS: ALKa [n = 19], 26% [95% CI, 10 to 47], clonal ALKm [n = 65] 33% [95% CI, 21 to 44], subclonal ALKm (n = 22) 48% [95% CI, 26 to 67], and no alteration [n = 465], 51% [95% CI, 46 to 55], respectively; P = .001). Importantly, in a multivariate model, involvement of more than one metastatic compartment (hazard ratio [HR], 2.87; P < .001), ALKa (HR, 2.38; P = .004), and clonal ALKm (HR, 1.77; P = .001) were independent predictors of poor outcome. Genetic alterations of ALK (clonal mutations and amplifications) in HR-NB are independent predictors of poorer survival. These data provide a rationale for integration of ALK inhibitors in upfront treatment of HR-NB with ALK alterations

    Sleep-Deprivation Regulates α-2 Adrenergic Responses of Rat Hypocretin/Orexin Neurons

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    We recently demonstrated, in rat brain slices, that the usual excitation by noradrenaline (NA) of hypocretin/orexin (hcrt/orx) neurons was changed to an inhibition following sleep deprivation (SD). Here we describe that in control condition (CC), i.e. following 2 hours of natural sleep in the morning, the α2-adrenergic receptor (α2-AR) agonist, clonidine, had no effect on hcrt/orx neurons, whereas following 2 hours of SD (SDC), it hyperpolarized the neurons by activating G-protein-gated inwardly rectifying potassium (GIRK) channels. Since concentrations of clonidine up to a thousand times (100 µM) higher than those effective in SDC (100 nM), were completely ineffective in CC, a change in the availability of G-proteins is unlikely to explain the difference between the two conditions. To test whether the absence of effect of clonidine in CC could be due to a down-regulation of GIRK channels, we applied baclofen, a GABAB agonist known to also activate GIRK channels, and found that it hyperpolarized hcrt/orx neurons in that condition. Moreover, baclofen occluded the response to clonidine in SDC, indicating that absence of effect of clonidine in CC could not be attributed to down-regulation of GIRK channels. We finally tested whether α2-ARs were still available at the membrane in CC and found that clonidine could reduce calcium currents, indicating that α2-ARs associated with calcium channels remain available in that condition. Taken together, these results suggest that a pool of α2-ARs associated with GIRK channels is normally down-regulated (or desensitized) in hcrt/orx neurons to only become available for their inhibition following sleep deprivation
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