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51.
Alex F?rster Hans Ulrich Kerl Holger Wenz Marc A. Brockmann Ingo N?lte Christoph Groden 《PloS one》2013,8(10)
Purpose
Characterization of lacunar infarction (LI) by use of multimodal MRI including diffusion- and perfusion-weighted imaging (DWI, PWI) is difficult because of the small lesion size. Only a few studies evaluated PWI in LI and the results are inconsistent.Methods
In 16 LI patients who underwent initial MRI within 6 hours after symptom onset and follow-up MRI within 1 week demographics, clinical presentation, and MRI findings were analyzed with special emphasis on DWI and PWI findings. Time to peak maps were classified as showing a normal perfusion pattern or areas of hypoperfusion which were further categorized in mismatch (PWI>DWI), inverse mismatch (PWI<DWI), and match (PWI=DWI). Quantitative perfusion maps were generated and analyzed by use of Signal Processing in NMR-Software (SPIN).Results
Of the 16 patients (mean age 65.5±12.9 years), 14 (87.5%) were male. Clinical symptoms comprised dysarthria (50%), hemiparesis (81.3%), and hemihypaesthesia (18.8%). Intravenous thrombolysis was performed in 7 (43.8%) patients. Clinical improvement was observed in 12 patients (75 %), while 2 (12.5%) patients showed a deterioration and another 2 (12.5%) a stable course. Acute ischemic lesions (mean volume of 0.46±0.29 cm3) were located in the thalamus (n=8, 50%), internal capsule (n=4, 25%), corona Radiata (n=3, 18.8%) and the mesencephalon (n=1, 6.3%). Circumscribed hypoperfusion (mean volume 0.61±0.48 cm3) was evident in 10 (62.5%) patients. Of these, 3 patients demonstrated a match, 4 an inverse mismatch, and 3 a mismatch between DWI and PWI lesion. Mean CBF and CBV ratios were 0.65±0.28 and 0.84±0.41 respectively. Growth of DWI lesions was observed in 7 (43.8%) and reversal of DWI lesions in 3 (18.8%) patients.Conclusions
MRI allows identification of different DWI and PWI patterns in LI, including growth and reversal of ischemic lesions. Consequently, it may serve for a better characterization of this stroke subtype and support treatment decisions in daily clinical practice. 相似文献52.
Wenjing Li Piotr Łączyński Hermes E. Escalona Jonas Eberle Lizhi Huo Xiaosheng Chen Weidong Huang Bingxu Chen Dirk Ahrens Adam Ślipiński Wioletta Tomaszewska Xingmin Wang 《Systematic Entomology》2020,45(2):447-463
Ladybirds of the cosmopolitan tribe Chilocorini prey mainly on coccids and include several important biocontrol agents. The phylogenetic relationships of Chilocorini are poorly known. In this paper, we provide a phylogenetic reconstruction of Chilocorini containing all 27 genera based on five molecular markers and 86 adult morphological characters. Morphological character states were mapped on the combined data tree from Bayesian inference to analyse morphological traits of each genus. Sixteen morphological characters were selected to reconstruct the ancestral states using maximum parsimony and maximum likelihood methods. Divergence times were estimated based on the relaxed molecular clock approach. Our results indicate that Chilocorini, excluding Chilocorellus Miyatake, is monophyletic and closely related to Plotinini. The crown group Chilocorini was estimated to date back to the Middle Cretaceous. Anisorcus Crotch, Egius Mulsant, Phaenochilus Weise and Simmondsius Ahmad & Ghani are synonymized here with Chilocorus Leach ( syn.n. ). The genus Chilocorellus is excluded from Chilocorini. The split of current genera was estimated to have occurred during the Middle Paleogene to Late Paleogene. 相似文献
53.
Christian T?tzke Tatiana Miranda Wilfried Konrad Julien Gout Nikolay Kardjilov Martin Dawson Ingo Manke Anita Roth-Nebelsick 《Annals of botany》2013,111(4):723-730
Background and Aims
Cold neutron radiography was applied to directly observe embolism in conduits of liana stems with the aim to evaluate the suitability of this method for studying embolism formation and repair. Potential advantages of this method are a principally non-invasive imaging approach with low energy dose compared with synchrotron X-ray radiation, a good spatial and temporal resolution, and the possibility to observe the entire volume of stem portions with a length of several centimetres at one time.Methods
Complete and cut stems of Adenia lobata, Aristolochia macrophylla and Parthenocissus tricuspidata were radiographed at the neutron imaging facility CONRAD at the Helmholtz-Zentrum Berlin für Materialien und Energie, with each measurement cycle lasting several hours. Low attenuation gas spaces were separated from the high attenuation (water-containing) plant tissue using image processing.Key results
Severe cuts into the stem were necessary to induce embolism. The formation and temporal course of an embolism event could then be successfully observed in individual conduits. It was found that complete emptying of a vessel with a diameter of 100 µm required a time interval of 4 min. Furthermore, dehydration of the whole stem section could be monitored via decreasing attenuation of the neutrons.Conclusions
The results suggest that cold neutron radiography represents a useful tool for studying water relations in plant stems that has the potential to complement other non-invasive methods. 相似文献54.
Isaak Rieger Friederike Lang Birgit Kleinschmit Ingo Kowarik Arne Cierjacks 《Plant and Soil》2013,370(1-2):497-509
Aims
We analysed current carbon (C) stocks in fine root and aboveground biomass of riparian forests and influential environmental parameters on either side of a dike in the Donau-Auen National Park, Austria.Methods
On both sides of the dike, carbon (C) stock of fine roots (CFR) under four dominant tree species and of aboveground biomass (CAB) were assessed by topsoil cores (0–30 cm) and angle count sampling method respectively (n?=?48). C stocks were modeled, performing boosted regression trees (BRT).Results
Overall CFR was 2.8 t ha?1, with significantly higher C stocks in diked (DRF) compared to flooded riparian forests (FRF). In contrast to CFR, mean CAB was 123 t ha?1 and lower in DRF compared to FRF. However, dike construction was consistently ruled out as a predictor variable in BRT. CFR was influenced by the distance to the Danube River and the dominant tree species. CAB was mainly influenced by the magnitude of fluctuations in the groundwater table and the distances to the river and the low groundwater table.Conclusions
Despite pronounced differences in FRF and DRF, we conclude that there is only weak support that dikes directly influence C allocation in floodplain forests within the time scale considered (110 years). 相似文献55.
Heinke Jäger María José Alencastro Martin Kaupenjohann Ingo Kowarik 《Plant and Soil》2013,368(1-2):629-640
Background and aims
Salinity is an increasing problem for agricultural production worldwide. Understanding how Na+ enters plants is important if reducing Na+ influx, a key component of the regulation of Na+ accumulation in plants and improving salt tolerance of crop plants, is to be achieved. Our previous work indicated that two distinct low-affinity Na+ uptake pathways exist in the halophyte Suaeda maritima. Here, we report the external NaCl concentration at which uptake switches from pathway 1 to pathway 2 and the kinetics of the interaction between external K+ concentration and Na+ uptake and accumulation in S. maritima in order to determine the roles of K+ transporters or channels in low-affinity Na+ uptake.Methods
Na+ influx, Na+ and K+ accumulations in S. maritima exposed to various concentrations of NaCl (0–200 mM) were analyzed in the absence and presence of the inhibitors TEA and Ba+ (5 mM TEA or 3 mM Ba2+) or KCl (0, 10 or 50 mM).Results
Our earlier proposal was confirmed and extended that there are two distinct low-affinity Na+ uptake pathways in S. maritima: pathway 1 might be mediated by a HKT-type transporter under low salinity conditions and pathway 2 by an AKT1-type channel or a KUP/HAK/KT type transporter under high salinity conditions. The external NaCl concentration at which two distinct low-affinity Na+ uptake switches from pathway 1 to pathway 2, the ‘turning point’, is between 90 and 95 mM. Over a short period (12 h) of Na+ and K+ treatments, a low concentration of K+ (10 mM) facilitated Na+ uptake by S. maritima under high salinity (100–200 mM NaCl), whether or not the plants had been subjected to a longer (3 d) period of K+ starvation. The kinetics suggests that low concentration of K+ (10 mM) might activate AKT1-type channels or KUP/HAK/KT-type transporters under high salinity (100–200 mM NaCl).Conclusions
The turning-point of external NaCl concentrations for the two low-affinity Na+ uptake pathways in Suaeda maritima is between 90 and 95 mM. A low concentration of K+ (10 mM) might activate AKT1 or KUP/HAK/KT and facilitate Na+ uptake under high salinity (100–200 mM NaCl). The kinetics of K+ on Na+ uptake and accumulation in S maritima are also consistent with there being two low-affinity Na+ uptake pathways. 相似文献56.
Marion L?sing Ingo Goldbeck Birgit Manno Thomas Oellerich Tim Schnyder Hanibal Bohnenberger Bj?rn Stork Henning Urlaub Facundo D. Batista Jürgen Wienands Michael Engelke 《The Journal of biological chemistry》2013,288(4):2303-2313
Recruitment of the growth factor receptor-bound protein 2 (Grb2) by the plasma membrane-associated adapter protein downstream of kinase 3 (Dok-3) attenuates signals transduced by the B cell antigen receptor (BCR). Here we describe molecular details of Dok-3/Grb2 signal integration and function, showing that the Lyn-dependent activation of the BCR transducer kinase Syk is attenuated by Dok-3/Grb2 in a site-specific manner. This process is associated with the SH3 domain-dependent translocation of Dok-3/Grb2 complexes into BCR microsignalosomes and augmented phosphorylation of the inhibitory Lyn target SH2 domain-containing inositol 5′ phosphatase. Hence, our findings imply that Dok-3/Grb2 modulates the balance between activatory and inhibitory Lyn functions with the aim to adjust BCR signaling efficiency. 相似文献
57.
Ingo Rekittke Elena Olkhova Jochen Wiesner Ulrike Demmer Eberhard Warkentin Hassan Jomaa Ulrich Ermler 《FEBS letters》2013
Terpenoid precursor biosynthesis occurs in human and many pathogenic organisms via the mevalonate and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways, respectively. We determined the X-ray structure of the Fe/S containing (E)-4-hydroxy-3-methyl-but-2-enyl-diphosphate reductase (LytB) of the pathogenic protozoa Plasmodium falciparum which catalyzes the terminal step of the MEP pathway. The cloverleaf fold and the active site of P. falciparum LytB corresponds to those of the Aquifex aeolicus and Escherichia coli enzymes. Its distinct electron donor [2Fe–2S] ferredoxin was modeled to its binding site by docking calculations. The presented structural data provide a platform for a rational search of anti-malarian drugs. 相似文献
58.
Ayalew Ligaba Ingo Dreyer Armine Margaryan David J. Schneider Leon Kochian Miguel Piñeros 《The Plant journal : for cell and molecular biology》2013,76(5):766-780
Triticum aestivum aluminum‐activated malate transporter (TaALMT1) is the founding member of a unique gene family of anion transporters (ALMTs) that mediate the efflux of organic acids. A small sub‐group of root‐localized ALMTs, including TaALMT1, is physiologically associated with in planta aluminum (Al) resistance. TaALMT1 exhibits significant enhancement of transport activity in response to extracellular Al. In this study, we integrated structure–function analyses of structurally altered TaALMT1 proteins expressed in Xenopus oocytes with phylogenic analyses of the ALMT family. Our aim is to re‐examine the role of protein domains in terms of their potential involvement in the Al‐dependent enhancement (i.e. Al‐responsiveness) of TaALMT1 transport activity, as well as the roles of all its 43 negatively charged amino acid residues. Our results indicate that the N‐domain, which is predicted to form the conductive pathway, mediates ion transport even in the absence of the C‐domain. However, segments in both domains are involved in Al3+ sensing. We identified two regions, one at the N‐terminus and a hydrophobic region at the C‐terminus, that jointly contribute to the Al‐response phenotype. Interestingly, the characteristic motif at the N‐terminus appears to be specific for Al‐responsive ALMTs. Our study highlights the need to include a comprehensive phylogenetic analysis when drawing inferences from structure–function analyses, as a significant proportion of the functional changes observed for TaALMT1 are most likely the result of alterations in the overall structural integrity of ALMT family proteins rather than modifications of specific sites involved in Al3+ sensing. 相似文献
59.
Ingo V. Hartung Marion Hitchcock Florian Pühler Roland Neuhaus Arne Scholz Stefanie Hammer Kirstin Petersen Gerhard Siemeister Dominic Brittain Roman C. Hillig 《Bioorganic & medicinal chemistry letters》2013,23(8):2384-2390
Using PD325901 as a starting point for identifying novel allosteric MEK inhibitors with high cell potency and long-lasting target inhibition in vivo, truncation of its hydroxamic ester headgroup was combined with incorporation of alkyl and aryl ethers at the neighboring ring position. Whereas alkoxy side chains did not yield sufficient levels of cell potency, specifically substituted aryloxy groups allowed for high enzymatic and cellular potencies. Sulfamide 28 was identified as a highly potent MEK inhibitor with nanomolar cell potency against B-RAF (V600E) as well as Ras-mutated cell lines, high metabolic stability and resulting long half-lives. It was efficacious against B-RAF as well as K-Ras driven xenograft models and showed—despite being orally bioavailable and not a P-glycoprotein substrate—much lower brain/plasma exposure ratios than PD325901. 相似文献
60.
Joseph B. Ahrens Elizabeth Borda Rômulo Barroso Paulo C. Paiva Alexandra M. Campbell Alexander Wolf Maggy M. Nugues Greg W. Rouse Anja Schulze 《Molecular ecology》2013,22(8):2280-2291
Over the last few decades, advances in molecular techniques have led to the detection of strong geographic population structure and cryptic speciation in many benthic marine taxa, even those with long‐lived pelagic larval stages. Polychaete annelids, in particular, generally show a high degree of population divergence, especially in mitochondrial genes. Rarely have molecular studies confirmed the presence of ‘cosmopolitan’ species. The amphinomid polychaete Hermodice carunculata was long considered the sole species within its genus, with a reported distribution throughout the Atlantic and adjacent basins. However, recent studies have indicated morphological differences, primarily in the number of branchial filaments, between the East and West Atlantic populations; these differences were invoked to re‐instate Hermodice nigrolineata, formerly considered a junior synonym of H. carunculata. We utilized sequence data from two mitochondrial (cytochrome c oxidase subunit I, 16S rDNA) markers and one nuclear (internal transcribed spacer) marker to examine the genetic diversity of Hermodice throughout its distribution range in the Atlantic Ocean, including the Mediterranean Sea, the Caribbean Sea, the Gulf of Mexico and the Gulf of Guinea. Our analyses revealed generally low genetic divergences among collecting localities and between the East and West Atlantic, although phylogenetic trees based on mitochondrial data indicate the presence of a private lineage in the Mediterranean Sea. A re‐evaluation of the number of branchial filaments confirmed differences between East and West Atlantic populations; however, the differences were not diagnostic and did not reflect the observed genetic population structure. Rather, we suspect that the number of branchial filaments is a function of oxygen saturation in the environment. Our results do not support the distinction between H. carunculata in the West Atlantic and H. nigrolineata in the East Atlantic. Instead, they re‐affirm the older notion that H. carunculata is a cohesive species with a broad distribution across the Atlantic Ocean. 相似文献