0000000000267083

AUTHOR

Martin Müller

Steady-state neutrophil homeostasis is dependent on TLR4/TRIF signaling

Polymorphonuclear neutrophil granulocytes (neutrophils) are tightly controlled by an incompletely understood homeostatic feedback loop adjusting the marrow's supply to peripheral needs. Although it has long been known that marrow cellularity is inversely correlated with G-CSF levels, the mechanism linking peripheral clearance to production remains unknown. Herein, the feedback response to antibody induced neutropenia is characterized to consist of G-CSF–dependent shifts of marrow hematopoietic progenitor populations including expansion of the lin-/Sca-1/c-kit (LSK) and granulocyte macrophage progenitor (GMP) compartments at the expense of thrombopoietic and red cell precursors. Evidence is …

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Epidemiological survey of 214 families with bladder exstrophy-epispadias complex.

We sought to identify causative nongenetic and genetic risk factors for the bladder exstrophy-epispadias complex.A total of 237 families with the bladder exstrophy-epispadias complex were invited to participate in the study, and information was obtained from 214 families, mainly from European countries.Two families showed familial occurrence. Male predominance was found among all subgroups comprising epispadias, classic bladder exstrophy and cloacal exstrophy, with male-to-female ratios of 1.4:1, 2.8:1 and 2.0:1, respectively (p = 0.001). No association with parental age, maternal reproductive history or periconceptional maternal exposure to alcohol, drugs, chemical noxae, radiation or infe…

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Quantifying the trade-off between useful and parasitic absorption of light for plasmonic light trapping in thin silicon films

We apply a combination of photocurrent and photothermal spectroscopic techniques to experimentally quantify the trade-off between useful and parasitic absorption of light in thin hydrogenated microcrystalline silicon (?c-Si:H) films incorporating self-assembled silver nanoparticle arrays, located at the rear side, for improved light trapping via resonant plasmonic scattering. The photothermal technique is used to measure the total absorptance while the photocurrent spectroscopy accounts only for the photons absorbed in the ?c-Si:H layer (useful absorptance); therefore, the method allows for independent quantification of the useful and parasitic absorptance of the plasmonic (or any other) li…

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Experimental quantification of useful and parasitic absorption of light in plasmon-enhanced thin silicon films for solar cells application

AbstractA combination of photocurrent and photothermal spectroscopic techniques is applied to experimentally quantify the useful and parasitic absorption of light in thin hydrogenated microcrystalline silicon (μc-Si:H) films incorporating optimized metal nanoparticle arrays, located at the rear surface, for improved light trapping via resonant plasmonic scattering. The photothermal technique accounts for the total absorptance and the photocurrent signal accounts only for the photons absorbed in the μc-Si:H layer (useful absorptance); therefore, the method allows for independent quantification of the useful and parasitic absorptance of the plasmonic (or any other) light trapping structure. W…

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Bone Marrow Derived Mesenchymal Cells Secrete Granulopoietic Cytokines upon Danger Signaling

Abstract Granulopoietic homeostasis is regulated at steady-state to supply sufficient numbers of pooled and circulating neutrophils to maintain barrier function against commensal flora. In addition, upon pathogenic microbial challenge, an increased formation of neutrophils is induced, termed ‘emergency granulopoiesis’. Antibody-mediated reduction of neutrophil numbers in steady-state induces a feedback loop leading to an increase of bone marrow granulopoiesis with expansion of hematopoetic stem and progenitor cells. This feedback loop was demonstrated to depend on TLR4 and TRIF, but not MyD88 signaling (Bugl et al. Blood 2013). In contrast, emergency granulopoiesis was shown to be dependent…

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Nuclear Translocation of Papillomavirus Minor Capsid Protein L2 Requires Hsc70

ABSTRACT Minor capsid protein L2 of papillomaviruses plays an essential role in virus assembly by recruiting viral components to PML bodies, the proposed sites of virus morphogenesis. We demonstrate here that the function of L2 in virus assembly requires the chaperone Hsc70. Hsc70 was found dispersed in naturally infected keratinocytes and cultured cells. A dramatic relocation of Hsc70 from the cytoplasm to PML bodies was induced in these cells by L2 expression. Hsc70-L2 complex formation was confirmed by coimmunoprecipitation. The complex was modulated by the cochaperones Hip and Bag-1, which stabilize and destabilize Hsc70-substrate complexes, respectively. Cytoplasmic depletion of Hsc70 …

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Dynamic modulation of Dnmt2-dependent tRNA methylation by the micronutrient queuine

Dnmt2 enzymes are cytosine-5 methyltransferases that methylate C38 of several tRNAs. We report here that the activities of two Dnmt2 homologs, Pmt1 from Schizosaccharomyces pombe and DnmA from Dictyostelium discoideum, are strongly stimulated by prior queuosine (Q) modification of the substrate tRNA. In vivo tRNA methylation levels were stimulated by growth of cells in queuine-containing medium; in vitro Pmt1 activity was enhanced on Q-containing RNA; and queuine-stimulated in vivo methylation was abrogated by the absence of the enzyme that inserts queuine into tRNA, eukaryotic tRNA-guanine transglycosylase. Global analysis of tRNA methylation in S. pombe showed a striking selectivity of Pm…

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Current insights into neutrophil homeostasis

Neutrophil granulocytes represent the first immunologic barrier against invading pathogens, and neutropenia predisposes to infection. However, neutrophils may also cause significant collateral inflammatory damage. Therefore, neutrophil numbers are tightly regulated by an incompletely understood homeostatic feedback loop adjusting the marrow's supply to peripheral needs. Granulocyte colony-stimulating factor (G-CSF) is accepted to be the major determinant of neutrophil production, and G-CSF levels have, soon after its discovery, been described to be inversely correlated with neutrophil counts. A neutrophil sensor, or "neutrostat," has, therefore, been postulated. The prevailing feedback hypo…

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Phenotype severity in the bladder exstrophy-epispadias complex: analysis of genetic and nongenetic contributing factors in 441 families from North America and Europe.

Objective To identify genetic and nongenetic risk factors that contribute to the severity of the bladder exstrophy-epispadias complex (BEEC). Study design Patients with BEEC from North America (n = 167) and Europe (n = 274) were included. The following data were collected: associated anomalies, parental age at conception, mode of conception, periconceptional folic acid supplementation, maternal risk factors during pregnancy, and environmental risk factors. The patients were divided into 3 subgroups according to phenotype severity: (i) mild, epispadias (n = 43); (ii) intermediate, classic bladder exstrophy (n = 366); and (iii) severe, cloacal exstrophy (n = 31). These subgroups then were com…

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High BCR-ABL/GUSIS Levels At Diagnosis Are Associated With Unfavorable Responses To Imatinib

Abstract The approval of three tyrosine kinase inhibitors (TKIs) for the first line treatment of Chronic Myeloid Leukemia (CML) has generated an urgent need for molecular parameters predictive of unfavorable therapeutic outcomes. Recent evidence suggests that failure to achieve early molecular responses (i.e. BCR-ABL/ABLIS levels <10% after 3 months or <1% after 6 months of TKI treatment) results in inferior rates of both overall and progression-free survival. With the current study, we wanted to establish if high BCR-ABL transcripts at diagnosis would be associated with unfavorable responses to Imatinib Mesylate (IM). Thus, we correlated quantitative determinations of BCR-ABL levels …

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PARP inhibitor resistance induces massive genome alterations responsible of the acquisition of multidrug resistance in DNA damage repair-deficient pancreatic cancer

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Direct measurement of optical losses in plasmon-enhanced thin silicon films (Conference Presentation)

Plasmon-enhanced absorption, often considered as a promising solution for efficient light trapping in thin film silicon solar cells, suffers from pronounced optical losses i.e. parasitic absorption, which do not contribute to the obtainable photocurrent. Direct measurements of such losses are therefore essential to optimize the design of plasmonic nanostructures and supporting layers. Importantly, contributions of useful and parasitic absorption cannot be measured separately with commonly used optical spectrophotometry. In this study we apply a novel strategy consisting in a combination of photocurrent and photothermal spectroscopic techniques to experimentally quantify the trade-off betwee…

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