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排序方式: 共有398条查询结果,搜索用时 15 毫秒
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Gerhard Obermeyer Hildegard Klaushofer Marion Nagl Margit Höftberger Friedrich-Wilhelm Bentrup 《Planta》1998,207(2):303-312
Inhibitors of type-2A protein phosphatase (PPase-2A), calyculin A (cal A) and okadaic acid (OA), inhibit pollen grain germination
and growth of pollen tubes of Lilium longiflorum Thunb. at nanomolar concentrations. Half-maximal inhibition of cytoplasmic PPase-2A activity was below 0.1 nM for cal A and
at 0.7 nM for OA. Other protein phosphatase inhibitors (tautomycin, cypermethrin, and dephostatin) were less effective. The
OA- and cal A-sensitive as well as dephostatin-sensitive PPase activity in the cytoplasm did not change during germination
and growth of pollen tubes. Addition of cal A and OA disturbed the direction of pollen tube growth and the distribution of
cytoplasmic organelles and caused cell wall thickenings as observed by light and electron microscopy. Inhibition of PPase-2A
caused multiple effects at the cellular level, cytoskeletal elements being a putative target of PPase-2A activity.
Received: 30 March 1998 / Accepted: 6 July 1998 相似文献
23.
Anna Conen Reno Frei Hildegard Adler Marc Dangel Christoph A. Fux Andreas F. Widmer 《PloS one》2015,10(3)
Objectives
Plasmid-mediated AmpC beta-lactamase-producing (pAmpC) Enterobacteriaceae are increasing worldwide, difficult to identify and often confounded with extended-spectrum beta-lactamase (ESBL) producers. The low prevalence precludes routine universal admission screening. Therefore, we evaluated potential risk factors for carriage of pAmpC-producing Enterobacteriaceae that would allow targeted screening to improve yield and reduce cost.Patients and methods
We performed a case control study at a tertiary care center from 1/2006 to 12/2010. Cases were adult patients in whom pAmpC-producing Enterobacteriaceae were isolated; controls were chosen among carriers of ESBL-producing Enterobacteriaceae. Both infected and colonized patients were included.Results
Over five years, we identified 40 pAmpC producers in 39 patients among 16,247 screened consecutive isolates of Enterobacteriaceae. The pAmpC prevalence was low (0.25%), but more than 30% of pAmpC carriers received incorrect empirical antibiotic treatment. When compared with 39 ESBL controls, pAmpC carriage was associated with clinically confirmed infections in 74% (versus 51%) (p=0.035), mainly of the urinary tract, previous antibiotic exposure in 63% (versus 36%) (p=0.035) and carriage of a nasogastric tube in 23% (versus 0%) (p=0.002). In the multivariate regression analysis only clinically confirmed infections remained significantly associated with pAmpC carriage (OR 1.44 (95%CI 1.15-2.57)). No other clinical and blood test-associated risk factor allowed discrimination of pAmpC-carrying patients from ESBL controls. The type of acquisition – nosocomial versus community-acquired – was also non-informative for resistance type, as 46% of pAmpC- and 44% of ESBL-producing Enterobacteriaceae were community-acquired.Conclusions
This study could not identify a clinical profile that would allow targeted screening for pAmpC-producing Enterobacteriaceae when compared to ESBL carriers. Because empiric antimicrobial therapy was inappropriate in more than 30%, rapid identification of pAmpC carriers is needed. New microbiological methods are therefore required to simplify rapid and reliable detection of pAmpC carriers. 相似文献24.
Hypomorphic mutations in the gene encoding a key Fanconi anemia protein, FANCD2, sustain a significant group of FA-D2 patients with severe phenotype 下载免费PDF全文
Kalb R Neveling K Hoehn H Schneider H Linka Y Batish SD Hunt C Berwick M Callen E Surralles J Casado JA Bueren J Dasi A Soulier J Gluckman E Zwaan CM van Spaendonk R Pals G de Winter JP Joenje H Grompe M Auerbach AD Hanenberg H Schindler D 《American journal of human genetics》2007,80(5):895-910
FANCD2 is an evolutionarily conserved Fanconi anemia (FA) gene that plays a key role in DNA double-strand-type damage responses. Using complementation assays and immunoblotting, a consortium of American and European groups assigned 29 patients with FA from 23 families and 4 additional unrelated patients to complementation group FA-D2. This amounts to 3%-6% of FA-affected patients registered in various data sets. Malformations are frequent in FA-D2 patients, and hematological manifestations appear earlier and progress more rapidly when compared with all other patients combined (FA-non-D2) in the International Fanconi Anemia Registry. FANCD2 is flanked by two pseudogenes. Mutation analysis revealed the expected total of 66 mutated alleles, 34 of which result in aberrant splicing patterns. Many mutations are recurrent and have ethnic associations and shared allelic haplotypes. There were no biallelic null mutations; residual FANCD2 protein of both isotypes was observed in all available patient cell lines. These analyses suggest that, unlike the knockout mouse model, total absence of FANCD2 does not exist in FA-D2 patients, because of constraints on viable combinations of FANCD2 mutations. Although hypomorphic mutations arie involved, clinically, these patients have a relatively severe form of FA. 相似文献
25.
Michael L. Collyer Craig A. Stockwell Dean C. Adams M. Hildegard Reiser 《Ecological Research》2007,22(6):902-910
Contemporary evolution has been shown in a few studies to be an important component of colonization ability, but seldom have
researchers considered whether phenotypic plasticity facilitates directional evolution from the invasion event. In the current
study, we evaluated body shape divergence of the New Mexico State-threatened White Sands pupfish (Cyprinodon tularosa) that were introduced to brackish, lacustrine habitats at two different time in the recent past (approximately 30 years and
1 year previously) from the same source population (saline river environment). Pupfish body shape is correlated with environmental
salinity: fish from saline habitats are characterized by slender body shapes, whereas fish from fresher, yet brackish springs
are deep-bodied. In this study, lacustrine populations consisted of an approximately 30-year old population and several 1-year
old populations, all introduced from the same source. The body shape divergence of the 30-year old population was significant
and greater than any of the divergences of the 1-year old populations (which were for the most part not significant). Nonetheless,
all body shape changes exhibited body deepening in less saline environments. We conclude that phenotypic plasticity potentially
facilitates directional evolution of body deepening for introduced pupfish populations. 相似文献
26.
Response of cells on surface-induced nanopatterns: fibroblasts and mesenchymal progenitor cells 总被引:1,自引:0,他引:1
Khor HL Kuan Y Kukula H Tamada K Knoll W Moeller M Hutmacher DW 《Biomacromolecules》2007,8(5):1530-1540
Ultrathin films of a poly(styrene)-block-poly(2-vinylpyrindine) diblock copolymer (PS-b-P2VP) and poly(styrene)-block-poly(4-vinylpyrindine) diblock copolymer (PS-b-P4VP) were used to form surface-induced nanopattern (SINPAT) on mica. Surface interaction controlled microphase separation led to the formation of chemically heterogeneous surface nanopatterns on dry ultrathin films. Two distinct nanopatterned surfaces, namely, wormlike and dotlike patterns, were used to investigate the influence of topography in the nanometer range on cell adhesion, proliferation, and migration. Atomic force microscopy was used to confirm that SINPAT was stable under cell culture conditions. Fibroblasts and mesenchymal progenitor cells were cultured on the nanopatterned surfaces. Phase contrast and confocal laser microscopy showed that fibroblasts and mesenchymal progenitor cells preferred the densely spaced wormlike patterns. Atomic force microscopy showed that the cells remodelled the extracellular matrix differently as they migrate over the two distinctly different nanopatterns. 相似文献
27.
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29.
Michael Seyffert Daniel L. Glauser Kurt Tobler Oleg Georgiev Rebecca Vogel Bernd Vogt Leticia Agúndez Michael Linden Hildegard Büning Mathias Ackermann Cornel Fraefel 《Journal of virology》2015,89(21):11150-11158
Adeno-associated virus type 2 is known to inhibit replication of herpes simplex virus 1 (HSV-1). This activity has been linked to the helicase- and DNA-binding domains of the Rep68/Rep78 proteins. Here, we show that Rep68 can bind to consensus Rep-binding sites on the HSV-1 genome and that the Rep helicase activity can inhibit replication of any DNA if binding is facilitated. Therefore, we hypothesize that inhibition of HSV-1 replication involves direct binding of Rep68/Rep78 to the HSV-1 genome. 相似文献
30.
von der Lieth CW Freire AA Blank D Campbell MP Ceroni A Damerell DR Dell A Dwek RA Ernst B Fogh R Frank M Geyer H Geyer R Harrison MJ Henrick K Herget S Hull WE Ionides J Joshi HJ Kamerling JP Leeflang BR Lütteke T Lundborg M Maass K Merry A Ranzinger R Rosen J Royle L Rudd PM Schloissnig S Stenutz R Vranken WF Widmalm G Haslam SM 《Glycobiology》2011,21(4):493-502
The EUROCarbDB project is a design study for a technical framework, which provides sophisticated, freely accessible, open-source informatics tools and databases to support glycobiology and glycomic research. EUROCarbDB is a relational database containing glycan structures, their biological context and, when available, primary and interpreted analytical data from high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance experiments. Database content can be accessed via a web-based user interface. The database is complemented by a suite of glycoinformatics tools, specifically designed to assist the elucidation and submission of glycan structure and experimental data when used in conjunction with contemporary carbohydrate research workflows. All software tools and source code are licensed under the terms of the Lesser General Public License, and publicly contributed structures and data are freely accessible. The public test version of the web interface to the EUROCarbDB can be found at http://www.ebi.ac.uk/eurocarb. 相似文献