bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of strawberry (Fragaria L.) genetic resources for resistance to Botrytis cinerea
Authors: Bestfleisch M. , Luderer‐Pflimpfl M. , Höfer M. , Schulte E. , Wünsche J. N. , Hanke M.‐V. , Flachowsky H. 
Published: July 2014

The grey mould disease caused by Botrytis cinerea leads to substantial economic losses in strawberry production all over the world. Control of the disease requires an extensive amount of fungicide that is applied in varying complexes because the pathogen easily develops resistance against the active compounds. Planting of resistant cultivars seems to be a promising alternative for fruit growers, but there are currently no cultivars available combining resistance to B. cinerea with attractive horticultural traits. Breeding of new cultivars requires the effective identification of resistant strawberry genotypes; therefore the current study was aimed at the evaluation of strawberry genetic resources under controlled conditions by establishing an artificial inoculation assay. The method presented in this study is an artificial inoculation of ripe fruits with a defined spore suspension under laboratory conditions. The results show that this assay is fast and simple and leads to reproducible results that correlate with field observations. Over 3 years a total of 107 strawberry genotypes of the German National Fruit Genebank at the JKI in Dresden‐Pillnitz were evaluated. Five partly resistant genotypes, cultivars Diana, Joerica and Kimberly, and Fragaria virginiana ‘Wildmare Creek’ and F. vesca subsp. bracteata, were identified with mean disease levels of <20% at 6 days post‐inoculation. The obtained results are discussed with regard to future breeding activities.
The Suppressive Function of Human CD8+ iTregs is Inhibited by IL‐1β and TNFα
Authors: Bjarnadottir U. , Lemarquis A. L. , Halldorsdottir S. , Freysdottir J. , Ludviksson B. R. 
Published: July 2014

AbstractCD8+ Tregs display an immunoregulatory activity and may play an essential role in the immunopathology of several diseases. Therefore, their therapeutic potential is exquisite and further studies on their differentiation and function are essential. The aim of this study was to evaluate the role of the innate immune system in CD8+ iTreg differentiation and function. Naive human CD8+CD25−CD45RA+ T cells were cultured in Treg‐inducing conditions with or without IL‐1β, TNFα or monocyte‐derived dendritic cells (DCs). The differentiation of CD8+CD127−CD25hiFoxP3hi‐induced Tregs (CD8+ iTregs) is dependent on TGF‐β1 and IL‐2, which had synergistic effect upon their differentiation. CD8+ iTregs were also induced in a coculture with allogeneic mature DCs (mDCs). The CD8+ iTregs suppressive function was confirmed, which was diminished in the presence of IL‐1β and TNFα. The IL‐1β‐prevented suppressive function was associated with reduced secretion of IL‐10 and IFNγ, whereas the presence of TNFα did not affect their secretion. Furthermore, the presence of TNFα reduced IL‐10 and TGF‐β1 secretion by CD8+ iTregs, whereas only IL‐10 secretion was decreased by IL‐1β. Together, these results suggest that IL‐1β and TNFα prevent IL‐2‐ and TGF‐β1‐driven CD8+ iTregs suppressive function in human T cells. Such pro‐inflammatory innate immune response possibly mediates its negative tolerogenic effect through reduced IFNγ‐, IL‐10‐ and TGF‐β1‐driven mechanism.
A key general stress response motif is regulated non‐uniformly by CAMTA transcription factors
Authors: Benn Geoffrey , Wang Chang‐Quan , Hicks Derrick R. , Stein Jeffrey , Guthrie Cade , Dehesh Katayoon 
Published: July 2014

SummaryPlants cope with environmental challenges by rapidly triggering and synchronizing mechanisms governing stress‐specific and general stress response (GSR) networks. The GSR acts rapidly and transiently in response to various stresses, but the underpinning mechanisms have remained elusive. To define GSR regulatory components we have exploited the Rapid Stress Response Element (RSRE), a previously established functional GSR motif, using Arabidopsis plants expressing a 4xRSRE::Luciferase (RSRE::LUC) reporter. Initially, we searched public microarray datasets and found an enrichment of RSRE in promoter sequences of stress genes. Next, we treated RSRE::LUC plants with wounding and a range of rapidly stress‐inducible hormones and detected a robust LUC activity solely in response to wounding. Application of two Ca2+ burst inducers, flagellin22 (flg22) and oligogalacturonic acid, activated RSRE strongly and systemically, while the Ca2+ chelator ethylene glycol tetraacetic acid (EGTA) significantly reduced wound induction of RSRE::LUC. In line with the signaling function of Ca2+ in transduction events leading to activation of RSRE, we examined the role of CALMODULIN‐BINDING TRANSCRIPTIONAL ACTIVATORs (CAMTAs) in RSRE induction. Transient expression assays displayed CAMTA3 induction of RSRE and not that of the mutated element mRSRE. Treatment of selected camta mutant lines integrated into RSRE::LUC parent plant, with wounding, flg22, and freezing, established a differential function of these CAMTAs in potentiating the activity of RSRE. Wound response studies using camta double mutants revealed a cooperative function of CAMTAs2 and 4 with CAMTA 3 in the RSRE regulation. These studies provide insights into governing components of transduction events and reveal transcriptional modules that tune the expression of a key GSR motif.
Double disruption of α2A‐ and α2C‐adrenoceptors induces endothelial dysfunction in mouse small arteries: role of nitric oxide synthase uncoupling
Authors: Couto Gisele K. , Davel Ana P. , Brum Patrícia C. , Rossoni Luciana V. 
Published: July 2014

New Findings
What is the central question of this study?
Knockout mice lacking both α2A‐ and α2C‐adrenergic receptors (α2A/α2C‐ARKO) provide a model for understanding the mechanisms underlying the deleterious effects of sympathetic hyperactivity on the cardiovascular system. The purpose of this study was to compare the effects of sympathetic hyperactivity on the vascular reactivity of large and small arteries from α2A/α2C‐ARKO mice and to evaluate the role of nitric oxide and oxidative stress.
What is the main finding and its importance?
We show that sympathetic hyperactivity alters vascular reactivity only in small arteries. Uncoupling endothelial nitric oxide synthase may be a significant source of superoxide anion and reduced NO bioavailability in small arteries from α2A/α2C‐ARKO mice, increasing the contractile tone.
Knockout mice lacking both α2A‐ and α2C‐adrenergic receptors (α2A/α2C‐ARKO) provide a model for understanding the mechanisms underlying the deleterious effects of sympathetic hyperactivity on the cardiovascular system. Thus, in the present study we investigated the vascular reactivity of large and small arteries of α2A/α2C‐ARKO mice. Aorta and mesenteric small arteries (MSAs) from 7‐month‐old male α2A/α2C‐ARKO mice and congenic C57BL6/J mice (wild‐type, WT) were studied. In the aorta, noradrenaline‐ and serotonin‐induced contraction was similar between groups, but in MSAs there was an increase in agonist‐induced contraction in α2A/α2C‐ARKO compared with WT. The l‐NAME effect was reduced in MSAs of α2A/α2C‐ARKO mice compared with WT mice, as was basal NO evaluated by a 4,5‐diaminofluorescein diacetate probe. Increased total endothelial nitric oxide synthase (eNOS) protein expression was observed in MSAs from α2A/α2C‐ARKO mice, while the dimer/monomer ratio of eNOS was decreased. Mesenteric small arteries from α2A/α2C‐ARKO mice showed an increase in ethidium bromide‐positive nuclei, indicating oxidative stress, which was attenuated by incubation with l‐NAME. The sympathetic hyperactivity present in α2A/α2C‐ARKO mice alters vascular reactivity only in certain types of arteries. Moreover, after chronic sympathetic hyperactivity, uncoupling eNOS may be a significant source of superoxide anion and reduced NO bioavailability in small vessels, increasing the contractile tone.
Association beween resting heart rate, shear and flow‐mediated dilation in healthy adults
Authors: Fox Brandon M. , Brantley Lucy , White Claire , Seigler Nichole , Harris Ryan A. 
Published: July 2014

New Findings
What is the central question of this study?
The aim was to explore the relationships among resting heart rate, shear and endothelial function in humans.
What is the main finding and its importance?
The main finding is that resting heart rate is associated with shear and endothelial function in humans. This finding could have implications when studying endothelial function in humans with varying heart rates.
Preclinical data have demonstrated that heart rate (HR) can directly impact vascular endothelial function, in part, through a shear‐stress mechanism. This study sought to explore, in humans, the associations between resting heart rate and both shear and endothelial function assessed by flow‐mediated dilation (FMD). The brachial artery FMD test was performed in 31 apparently healthy volunteers. Basal (B) and hyperaemic (H) shear were quantified in the following two ways using data from the FMD test: the traditional cumulative shear area under the curve up to peak dilation (Shearcum) method; and our novel method of shear summation (Shearsum), which accounts for HR by summing each individual cardiac cycle shear up to peak dilation. Data were grouped by tertiles based on resting HR as follows: low (LHR = 43–56 beats min−1; n = 10); middle (MHR = 58–68 beats min−1; n = 11); and high (HHR = 69–77 beats min−1; n = 10). Within the LHR group, both B‐Shearcum and H‐Shearcum were significantly higher (P < 0.001) than B‐Shearsum and H‐Shearsum, respectively, whereas in the HHR group B‐Shearcum and H‐Shearcum were significantly lower (P < 0.001) than B‐Shearsum and H‐Shearsum, respectively. The FMD in the LHR group (8.8 ± 0.8%) was significantly greater than that in both the MHR group (5.5 ± 0.8%; P = 0.009) and the HHR group (5.9 ± 0.8%; P = 0.024). These findings demonstrate the existence of a relationship between heart rate and both shear and endothelial function in humans. Moreover, these findings have implications for considering heart rate as an important physiological variable when quantifying shear and performing the FMD test.
Silencing of Kir2 channels by caveolin‐1: cross‐talk with cholesterol
Authors: Han Huazhi , Rosenhouse‐Dantsker Avia , Gnanasambandam Radhakrishnan , Epshtein Yulia , Chen Zhenlong , Sachs Frederick , Minshall Richard D. , Levitan Irena 
Published: July 2014

Key points
Inwardly rectifying potassium channels (Kir) play key roles in regulating membrane excitability and K+ homeostasis in multiple cell types. Our earlier studies showed that Kir2 channels, one of the major subfamilies of Kir, are suppressed by membrane cholesterol and that cholesterol stabilizes these channels in a closed ‘silent’ state.
This paper addresses a fundamental question of how Kir2 channels are regulated by caveolins, the major structural proteins of caveolae, and the relationship between the sensitivity of the channels to caveolin and to cholesterol.
In this study, we present direct evidence that caveolin‐1 is a negative regulator of Kir2 function and that cholesterol and caveolin‐1 regulate the channels by a common mechanism.
This study also challenges a general notion that cholesterol depletion alters ion channel function by disrupting caveolae, demonstrating that neither caveolin‐1 nor intact caveolae are required for cholesterol sensitivity of Kir2 channels.
Furthermore, we present first insights into the structural determinants of the cross‐talk between the sensitivity of Kir2 channels to caveolin and to cholesterol.
AbstractA growing number of studies show that different types of ion channels localize in caveolae and are regulated by the level of membrane cholesterol. Furthermore, it has been proposed that cholesterol‐induced regulation of ion channels might be attributed to partitioning into caveolae and association with caveolin‐1 (Cav‐1). We tested, therefore, whether Cav‐1 regulates the function of inwardly rectifying potassium channels Kir2.1 that play major roles in the regulation of membrane potentials of numerous mammalian cells. Our earlier studies demonstrated that Kir2.1 channels are cholesterol sensitive. In this study, we show that Kir2.1 channels co‐immunoprecipitate with Cav‐1 and that co‐expression of Kir2.1 channels with Cav‐1 in HEK293 cells results in suppression of Kir2 current indicating that Cav‐1 is a negative regulator of Kir2 function. These observations are confirmed by comparing Kir currents in bone marrow‐derived macrophages isolated from Cav‐1−/− and wild‐type animals. We also show, however, that Kir2 channels maintain their sensitivity to cholesterol in HEK293 cells that have very low levels of endogenous Cav‐1 and in bone marrow‐derived macrophages isolated from Cav‐1−/− knockout mice. Thus, these studies indicate that Cav‐1 and/or intact caveolae are not required for cholesterol sensitivity of Kir channels. Moreover, a single point mutation of Kir2.1, L222I that abrogates the sensitivity of the channels to cholesterol also abolishes their sensitivity to Cav‐1 suggesting that the two modulators regulate Kir2 channels via a common mechanism.
A new and fast image feature selection method for developing an optimal mammographic mass detection scheme
Authors: Tan Maxine , Pu Jiantao , Zheng Bin 
Published: July 2014

Purpose:Selecting optimal features from a large image feature pool remains a major challenge in developing computer‐aided detection (CAD) schemes of medical images. The objective of this study is to investigate a new approach to significantly improve efficacy of image feature selection and classifier optimization in developing a CAD scheme of mammographic masses.Methods:An image dataset including 1600 regions of interest (ROIs) in which 800 are positive (depicting malignant masses) and 800 are negative (depicting CAD‐generated false positive regions) was used in this study. After segmentation of each suspicious lesion by a multilayer topographic region growth algorithm, 271 features were computed in different feature categories including shape, texture, contrast, isodensity, spiculation, local topological features, as well as the features related to the presence and location of fat and calcifications. Besides computing features from the original images, the authors also computed new texture features from the dilated lesion segments. In order to select optimal features from this initial feature pool and build a highly performing classifier, the authors examined and compared four feature selection methods to optimize an artificial neural network (ANN) based classifier, namely: (1) Phased Searching with NEAT in a Time‐Scaled Framework, (2) A sequential floating forward selection (SFFS) method, (3) A genetic algorithm (GA), and (4) A sequential forward selection (SFS) method. Performances of the four approaches were assessed using a tenfold cross validation method.Results:Among these four methods, SFFS has highest efficacy, which takes 3%–5% of computational time as compared to GA approach, and yields the highest performance level with the area under a receiver operating characteristic curve (AUC) = 0.864 ± 0.034. The results also demonstrated that except using GA, including the new texture features computed from the dilated mass segments improved the AUC results of the ANNs optimized using other three feature selection methods. In addition, among 271 features, the shape, local morphological features, fat and calcification based features were the most frequently selected features to build ANNs.Conclusions:Although conventional GA is a powerful tool in optimizing classifiers used in CAD schemes of medical images, it is very computationally intensive. This study demonstrated that using a new SFFS based approach enabled to significantly improve efficacy of image feature selection for developing CAD schemes.
Microcystin Production and Regulation under Nutrient Stress Conditions in Toxic Microcystis Strains
Authors: Pimentel Juliana S. M. , Giani Alessandra 
Published: July 2014

ABSTRACT

Microcystin is a common and well-known cyanobacterial toxin whose intracellular role is still under investigation. Increasing knowledge on microcystin gene expression and regulation can contribute to the understanding of its putative cellular function. In this work, reverse transcription-quantitative PCR (RT-qPCR) was used to investigate the transcriptional response of the
mcyD
gene to nitrogen (nitrate and ammonium) and phosphorus limitation in two toxic
Microcystis
strains. The existence of a direct correlation between transcripts of
mcyD
and
ntcA
genes was also identified. In previous studies, NtcA (global nitrogen regulator) has been described as a potential component in the control of microcystin biosynthesis. This research showed that stress agents linked to nutrient deprivation could lead to a significant increase of microcystin production in both strains studied. The more toxic strain proved to be more resistant to nutrient limitation. The similar outcomes of
mcyD
regulation observed for all nutrients suggest that this response can be linked to oxidative stress of cells undergoing adverse growth conditions.
Evidence of Environmental and Vertical Transmission of Burkholderia Symbionts in the Oriental Chinch Bug, Cavelerius saccharivorus (Heteroptera: Blissidae)
Authors: Itoh Hideomi , Aita Manabu , Nagayama Atsushi , Meng Xian-Ying , Kamagata Yoichi , Navarro Ronald , Hori Tomoyuki , Ohgiya Satoru , Kikuchi Yoshitomo 
Published: July 2014

ABSTRACT

The vertical transmission of symbiotic microorganisms is omnipresent in insects, while the evolutionary process remains totally unclear. The oriental chinch bug,
Cavelerius saccharivorus
(Heteroptera: Blissidae), is a serious sugarcane pest, in which symbiotic bacteria densely populate the lumen of the numerous tubule-like midgut crypts that the chinch bug develops. Cloning and sequence analyses of the 16S rRNA genes revealed that the crypts were dominated by a specific group of bacteria belonging to the genus
Burkholderia
of the
Betaproteobacteria
. The
Burkholderia
sequences were distributed into three distinct clades: the
Burkholderia cepacia
complex (BCC), the plant-associated beneficial and environmental (PBE) group, and the stinkbug-associated beneficial and environmental group (SBE). Diagnostic PCR revealed that only one of the three groups of
Burkholderia
was present in ∼89% of the chinch bug field populations tested, while infections with multiple
Burkholderia
groups within one insect were observed in only ∼10%. Deep sequencing of the 16S rRNA gene confirmed that the
Burkholderia
bacteria specifically colonized the crypts and were dominated by one of three
Burkholderia
groups. The lack of phylogenetic congruence between the symbiont and the host population strongly suggested host-symbiont promiscuity, which is probably caused by environmental acquisition of the symbionts by some hosts. Meanwhile, inspections of eggs and hatchlings by diagnostic PCR and egg surface sterilization demonstrated that almost 30% of the hatchlings vertically acquire symbiotic
Burkholderia
via symbiont-contaminated egg surfaces. The mixed strategy of symbiont transmission found in the oriental chinch bug might be an intermediate stage in evolution from environmental acquisition to strict vertical transmission in insects.
Vitamin B
6
Generated by Obligate Symbionts Is Critical for Maintaining Proline Homeostasis and Fecundity in Tsetse Flies
Authors: Michalkova Veronika , Benoit Joshua B. , Weiss Brian L. , Attardo Geoffrey M. , Aksoy Serap 
Published: July 2014

ABSTRACT

The viviparous tsetse fly utilizes proline as a hemolymph-borne energy source. In tsetse, biosynthesis of proline from alanine involves the enzyme alanine-glyoxylate aminotransferase (AGAT), which requires pyridoxal phosphate (vitamin B
6
) as a cofactor. This vitamin can be synthesized by tsetse's obligate symbiont,
Wigglesworthia glossinidia
. In this study, we examined the role of
Wigglesworthia
-produced vitamin B
6
for maintenance of proline homeostasis, specifically during the energetically expensive lactation period of the tsetse's reproductive cycle. We found that expression of
agat
, as well as genes involved in vitamin B
6
metabolism in both host and symbiont, increases in lactating flies. Removal of symbionts via antibiotic treatment of flies (aposymbiotic) led to hypoprolinemia, reduced levels of vitamin B
6
in lactating females, and decreased fecundity. Proline homeostasis and fecundity recovered partially when aposymbiotic tsetse were fed a diet supplemented with either yeast or
Wigglesworthia
extracts. RNA interference-mediated knockdown of
agat
in wild-type flies reduced hemolymph proline levels to that of aposymbiotic females. Aposymbiotic flies treated with
agat
short interfering RNA (siRNA) remained hypoprolinemic even upon dietary supplementation with microbial extracts or B vitamins. Flies infected with parasitic African trypanosomes display lower hemolymph proline levels, suggesting that the reduced fecundity observed in parasitized flies could result from parasite interference with proline homeostasis. This interference could be manifested by competition between tsetse and trypanosomes for vitamins, proline, or other factors involved in their synthesis. Collectively, these results indicate that the presence of
Wigglesworthia
in tsetse is critical for the maintenance of proline homeostasis through vitamin B
6
production.
Polyhydroxyfullerene Binds Cadmium Ions and Alleviates Metal-Induced Oxidative Stress in Saccharomyces cerevisiae
Authors: Pradhan Arunava , Pinheiro José Paulo , Seena Sahadevan , Pascoal Cláudia , Cássio Fernanda 
Published: July 2014

ABSTRACT

The water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeast
Saccharomyces cerevisiae
by exposing cells to Cd (≤5 mg liter
−1
) in the absence or presence of PHF (≤500 mg liter
−1
) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells.