排序方式: 共有127条查询结果,搜索用时 46 毫秒
71.
Barbara Klink Hrvoje Miletic Daniel Stieber Peter C. Huszthy Jaime Alberto Campos Valenzuela J?rg Balss Jian Wang Manja Schubert Per ?ystein Sakariassen Terje Sundstr?m Anja Torsvik Mads Aarhus Rupavathana Mahesparan Andreas von Deimling Lars Kaderali Simone P. Niclou Evelin Schr?ck Rolf Bjerkvig Janice M. Nigro 《PloS one》2013,8(3)
Oligodendroglioma poses a biological conundrum for malignant adult human gliomas: it is a tumor type that is universally incurable for patients, and yet, only a few of the human tumors have been established as cell populations in vitro or as intracranial xenografts in vivo. Their survival, thus, may emerge only within a specific environmental context. To determine the fate of human oligodendroglioma in an experimental model, we studied the development of an anaplastic tumor after intracranial implantation into enhanced green fluorescent protein (eGFP) positive NOD/SCID mice. Remarkably after nearly nine months, the tumor not only engrafted, but it also retained classic histological and genetic features of human oligodendroglioma, in particular cells with a clear cytoplasm, showing an infiltrative growth pattern, and harboring mutations of IDH1 (R132H) and of the tumor suppressor genes, FUBP1 and CIC. The xenografts were highly invasive, exhibiting a distinct migration and growth pattern around neurons, especially in the hippocampus, and following white matter tracts of the corpus callosum with tumor cells accumulating around established vasculature. Although tumors exhibited a high growth fraction in vivo, neither cells from the original patient tumor nor the xenograft exhibited significant growth in vitro over a six-month period. This glioma xenograft is the first to display a pure oligodendroglioma histology and expression of R132H. The unexpected property, that the cells fail to grow in vitro even after passage through the mouse, allows us to uniquely investigate the relationship of this oligodendroglioma with the in vivo microenvironment. 相似文献
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Evelin Young Ze-Yi Zheng Angela D. Wilkins Hee-Tae Jeong Min Li Olivier Lichtarge Eric C. Chang 《Molecular and cellular biology》2014,34(3):374-385
Ras can act on the plasma membrane (PM) to mediate extracellular signaling and tumorigenesis. To identify key components controlling Ras PM localization, we performed an unbiased screen to seek Schizosaccharomyces pombe mutants with reduced PM Ras. Five mutants were found with mutations affecting the same gene, S. pombe
erf2 (sp-erf2), encoding sp-Erf2, a palmitoyltransferase, with various activities. sp-Erf2 localizes to the trans-Golgi compartment, a process which is mediated by its third transmembrane domain and the Erf4 cofactor. In fission yeast, the human ortholog zDHHC9 rescues the phenotypes of sp-erf2 null cells. In contrast, expressing zDHHC14, another sp-Erf2-like human protein, did not rescue Ras1 mislocalization in these cells. Importantly, ZDHHC9 is widely overexpressed in cancers. Overexpressing ZDHHC9 promotes, while repressing it diminishes, Ras PM localization and transformation of mammalian cells. These data strongly demonstrate that sp-Erf2/zDHHC9 palmitoylates Ras proteins in a highly selective manner in the trans-Golgi compartment to facilitate PM targeting via the trans-Golgi network, a role that is most certainly critical for Ras-driven tumorigenesis. 相似文献
74.
Katharina Schramm Carola Marzi Claudia Schurmann Maren Carstensen Eva Reinmaa Reiner Biffar Gertrud Eckstein Christian Gieger Hans-J?rgen Grabe Georg Homuth Gabriele Kastenmüller Reedik M?gi Andres Metspalu Evelin Mihailov Annette Peters Astrid Petersmann Michael Roden Konstantin Strauch Karsten Suhre Alexander Teumer Uwe V?lker Henry V?lzke Rui Wang-Sattler Melanie Waldenberger Thomas Meitinger Thomas Illig Christian Herder Harald Grallert Holger Prokisch 《PloS one》2014,9(4)
75.
Chaiene Evelin Zago Sónia Silva Paula Volpato Sanitá Paula Aboud Barbugli Carla Maria Improta Dias Virgínia Barreto Lordello Carlos Eduardo Vergani 《PloS one》2015,10(4)
Polymicrobial biofilms are an understudied and a clinically relevant problem. This study evaluates the interaction between C. albicans, and methicillin- susceptible (MSSA) and resistant (MRSA) S. aureus growing in single- and dual-species biofilms. Single and dual species adhesion (90 min) and biofilms (12, 24, and 48 h) were evaluated by complementary methods: counting colony-forming units (CFU mL-1), XTT-reduction, and crystal violet staining (CV). The secretion of hydrolytic enzymes by the 48 h biofilms was also evaluated using fluorimetric kits. Scanning electron microscopy (SEM) was used to assess biofilm structure. The results from quantification assays were compared using two-way ANOVAs with Tukey post-hoc tests, while data from enzymatic activities were analyzed by one-way Welch-ANOVA followed by Games-Howell post hoc test (α = 0.05). C. albicans, MSSA and MRSA were able to adhere and to form biofilm in both single or mixed cultures. In general, all microorganisms in both growth conditions showed a gradual increase in the number of cells and metabolic activity over time, reaching peak values between 12 h and 48 h (ρ<0.05). C. albicans single- and dual-biofilms had significantly higher total biomass values (ρ<0.05) than single biofilms of bacteria. Except for single MRSA biofilms, all microorganisms in both growth conditions secreted proteinase and phospholipase-C. SEM images revealed extensive adherence of bacteria to hyphal elements of C. albicans. C. albicans, MSSA, and MRSA can co-exist in biofilms without antagonism and in an apparent synergistic effect, with bacteria cells preferentially associated to C. albicans hyphal forms. 相似文献
76.
Evelin?R.?PéliEmail author Gergana?Mihailova Snejanka?Petkova Zoltán?Tuba Katya?Georgieva 《Acta Physiologiae Plantarum》2012,34(3):947-955
The ecophysiological responses of the homoiochlorophyllous desiccation-tolerant (HDT) plant Haberlea rhodopensis showed that this plant could tolerate water deficit and both leaves and roots had high ability to survive severe desiccation.
The changes and correlation between CO2 assimilation, stomatal conductance, contents of photosynthetic pigments, root respiration and specific leaf area during dehydration–rehydration
cycle were investigated. The physiological activity of leaves and roots were examined in fully hydrated (control) plants and
during 72 h of dehydration, as well as following 96 h of rehydration every 6 and 24 h. After 6 h of dehydration, the stomatal
conductance declined and the intercellular CO2 concentration increased. The reduction in CO2 assimilation rate was observed after 54 h of dehydration. There was a good correlation between the root respiration and water
content. Our results showed that the plasticity of adaptation in leaves and roots were different during extreme water conditions.
Roots were more sensitive and reacted faster to water stress than leaves, but their activity rapidly recovered due to immediate
and efficient utilization of periodic water supply. 相似文献
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Mike Thiv Jean-Paul Ghogue Valentin Grob Konrad Huber Evelin Pfeifer Rolf Rutishauser 《Plant Systematics and Evolution》2009,283(1-2):57-77
The Podostemaceae are highly enigmatic plants which are restricted to submerged river-rock habitats. The availability of new material of nine taxa from continental Africa prompted this new study. Five species belonging to the genera Dicraeanthus, Leiothylax, Letestuella, Macropodiella, and Stonesia and another four species of the large genera Inversodicraea sensu stricto and Ledermanniella sensu stricto have been analysed for the first time. New anatomical and developmental data are described and illustrated by use of microtome sections and scanning electron microscopy. In parallel, phylogenetic analyses of all available sequence data of African Podostemaceae have been conducted using three plastid markers (matK, trnD-trnT, rpoB-trnC). Inversodicraea cf. bosii appears basal within the continental African clade. The remaining taxa are distributed in three, rather poorly supported, major clades which are consistent with their morphology: (1) the Inversodicraea clade is characterised by stem scales and contains members of the former Ledermanniella subg. Phyllosoma with either pollen-monads or dyads; (2) the Ledermanniella-Monad group consisting of Leiothylax, Letestuella, Macropodiella, Stonesia, and Ledermanniella species—all taxa without stem scales but showing pollen as single grains, with Monandriella linearifolia being basal to this clade; (3) the Ledermanniella-Dyad clade including Djinga, Dicraeanthus, and Ledermanniella species without stem scales but with pollen dyads. To reduce the polyphyly of Ledermanniella sensu lato (i.e. sensu C. Cusset) we propose restricting Ledermanniella to the species of the former subgenus Ledermanniella, resurrecting Monandriella as monotypic genus, and accepting the genus name Inversodicraea for members of Ledermanniella subg. Phyllosoma. 相似文献
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Flavia M Paro Maria C Almeida Evelin C Carnio Luiz G S Branco 《Journal of applied physiology》2003,94(1):271-277
It has been reported that systemic injection of arginine vasopressin (AVP) induces a drop in body core temperature (T(c)), but little is known about the mechanisms involved. Because glutamate is an important excitatory neurotransmitter involved in a number of thermoregulatory actions, in the present study, we tested the hypothesis that glutamate plays a role in systemic AVP-induced hypothermia. Wistar rats were pretreated intracerebroventricularly (icv) with kynurenic acid, an antagonist of l-glutamate ionotropic receptors, alpha-methyl-(4-carboxyphenyl)glycine (MCPG), an antagonist of l-glutamate metabotropic receptors, or saline 15 min before intravenous injection of AVP (2 microg/kg) or saline. T(c), brown adipose tissue (BAT) temperature, blood pressure, heart rate, and tail skin temperature were measured continuously. Administration of saline icv followed by intravenous AVP caused a significant drop in T(c) brought about by a reduction in BAT thermogenesis and an increase in heat loss through the tail. MCPG treatment (icv) did not affect the fall in T(c) induced by AVP. Treatment with kynurenic acid (icv) abolished AVP-induced hypothermia but did not affect the AVP-evoked rise in blood pressure or drop in heart rate and BAT temperature. Heat loss through the tail was significantly reduced in animals injected with AVP and pretrated with kynurenic acid. These data indicate that ionotropic receptors of l-glutamate in the central nervous system participate in peripheral AVP-induced hypothermia by affecting heat loss through the tail. 相似文献