bluuebunny/crossref_metadata_2025_split huggingface dataset:
Candida glabrata environmental stress response involves Saccharomyces cerevisiae Msn2/4 orthologous transcription factors
Authors: Roetzer Andreas , Gregori Christa , Jennings Ann Marie , Quintin Jessica , Ferrandon Dominique , Butler Geraldine , Kuchler Karl , Ammerer Gustav , Schüller Christoph 
Published: May 2008

SummaryWe determined the genome‐wide environmental stress response (ESR) expression profile of Candida glabrata, a human pathogen related to Saccharomyces cerevisiae. Despite different habitats, C. glabrata, S. cerevisiae, Schizosaccharomyces pombe and Candida albicans have a qualitatively similar ESR. We investigate the function of the C. glabrata syntenic orthologues to the ESR transcription factor Msn2. The C. glabrata orthologues CgMsn2 and CgMsn4 contain a motif previously referred to as HD1 (homology domain 1) also present in Msn2 orthologues from fungi closely related to S. cerevisiae. We show that regions including this motif confer stress‐regulated intracellular localization when expressed in S. cerevisiae. Site‐directed mutagenesis confirms that nuclear export of CgMsn2 in C. glabrata requires an intact HD1. Transcript profiles of CgMsn2/4 mutants and CgMsn2 overexpression strains show that they regulate a part of the CgESR. CgMsn2 complements a S. cerevisiae msn2 null mutant and in stressed C. glabrata cells, rapidly translocates from the cytosol to the nucleus. CgMsn2 is required for full resistance against severe osmotic stress and rapid and full induction of trehalose synthesis genes (TPS1, TPS2). Constitutive activation of CgMsn2 is detrimental for C. glabrata. These results establish an Msn2‐regulated general stress response in C. glabrata.
A role for Lon protease in the control of the acid resistance genes of Escherichia coli
Authors: Heuveling Johanna , Possling Alexandra , Hengge Regine 
Published: May 2008

SummaryLon protease is a major protease in cellular protein quality control, but also plays an important regulatory role by degrading various naturally unstable regulators. Here, we traced additional such regulators by identifying regulons with co‐ordinately altered expression in a lon mutant by genome‐wide transcriptional profiling. Besides many members of the RcsA regulon (which validates our approach as RcsA is a known Lon substrate), many genes of the σS‐dependent general stress response were upregulated in the lon mutant. However, the lon mutation did not affect σS levels nor σS activity in general, suggesting specific effects of Lon on secondary regulators involved in the control of subsets of σS‐controlled genes. Lon‐affected genes also included the major acid resistance genes (gadA, gadBC, gadE, hdeAB and hdeD), which led to the discovery that the essential acid resistance regulator GadE (whose expression is σS‐controlled) is degraded in vivo in a Lon‐dependent manner. GadE proteolysis is constitutive as it was observed even under conditions that induce the system (i.e. at low pH or during entry into stationary phase). GadE degradation was found to rapidly terminate the acid resistance response upon shift back to neutral pH and to avoid overexpression of acid resistance genes in stationary phase.
Mutations in the multi‐drug resistance regulator MRR1, followed by loss of heterozygosity, are the main cause of MDR1 overexpression in fluconazole‐resistant Candida albicans strains
Authors: Dunkel Nico , Blaß Julia , Rogers P. David , Morschhäuser Joachim 
Published: May 2008

SummaryOverexpression of the MDR1 gene, encoding a multi‐drug efflux pump of the major facilitator superfamily, is a major cause of resistance to the widely used antifungal agent fluconazole and other toxic substances in the fungal pathogen Candida albicans. We found that all tested clinical and in vitro generated C. albicans strains that had become fluconazole‐resistant by constitutive MDR1 upregulation contained mutations in the MRR1 gene, which encodes a transcription factor that controls MDR1 expression. Introduction of the mutated alleles into a drug‐susceptible C. albicans strain resulted in activation of the MDR1 promoter and multi‐drug resistance, confirming that the amino acid substitutions in Mrr1p were gain‐of‐function mutations that rendered the transcription factor constitutively active. The majority of the MDR1 overexpressing strains had become homozygous for the mutated MRR1 alleles, demonstrating that the increased resistance level conferred by two gain‐of‐function alleles provides sufficient advantage to select for the loss of heterozygosity in the presence of fluconazole both in vitro and within the human host during therapy. Loss of heterozygosity usually occurred by mitotic recombination between the two chromosome 3 homologues on which MRR1 is located, but evidence for complete loss of one chromosome and duplication of the chromosome containing the mutated MRR1 allele was also obtained in two in vitro generated fluconazole‐resistant strains. These results demonstrate that gain‐of‐function mutations in MRR1 are the major, if not the sole, mechanism of MDR1 overexpression in fluconazole‐resistant strains and that this transcription factor plays a central role in the development of drug resistance in C. albicans.
Abscisic acid signalling when soil moisture is heterogeneous: decreased photoperiod sap flow from drying roots limits abscisic acid export to the shoots
Authors: DODD IAN C. , EGEA GREGORIO , DAVIES WILLIAM J. 
Published: May 2008

ABSTRACTTo investigate the contribution of different parts of the root system to total sap flow and leaf xylem abscisic acid (ABA) concentration ([X‐ABA]leaf), individual sunflower (Helianthus annuus L.) shoots were grafted onto the root systems of two plants grown in separate pots and sap flow through each hypocotyl measured below the graft union. During deficit irrigation (DI), both pots received the same irrigation volumes, while during partial root zone drying (PRD) one pot (‘wet’) was watered and another (‘dry’) was not. During PRD, once soil water content (θ) decreased below a threshold, the fraction of sap flow from drying roots declined. As θ declined, root xylem ABA concentration increased in both irrigation treatments, and [X‐ABA]leaf increased in DI plants, but [X‐ABA]leaf of PRD plants actually decreased within a certain θ range. A simple model that weighted ABA contributions of wet and dry root systems to [X‐ABA]leaf according to the sap flow from each, better predicted [X‐ABA]leaf of PRD plants than either [X‐ABA]dry, [X‐ABA]wet or their mean. Model simulations revealed that [X‐ABA]leaf during PRD exceeded that of DI with moderate soil drying, but continued soil drying (such that sap flow from roots in drying soil ceased) resulted in the opposite effect.
The lack of alternative oxidase at low temperature leads to a disruption of the balance in carbon and nitrogen metabolism, and to an up‐regulation of antioxidant defence systems in Arabidopsis thaliana leaves
Authors: WATANABE CHIHIRO K. , HACHIYA TAKUSHI , TERASHIMA ICHIRO , NOGUCHI KO 
Published: May 2008

ABSTRACTAlternative oxidase (AOX) catalyses the ATP‐uncoupling cyanide (CN)‐resistant pathway. In this study, our aim was to clarify the physiological role of AOX at low temperature. We examined the effect of low‐temperature treatment on CN‐resistant respiration (CN‐resistant R) and on the transcription of respiratory components in wild‐type (WT) and aox1a knock‐out transgenic (aox1a) Arabidopsis thaliana plants. In WT leaves, the expression of AOX1a mRNA was strongly induced by the low‐temperature treatment, and thus CN‐resistant R increased during low‐temperature treatment. In aox1a, the CN‐sensitive respiration, and the expression of NDB2 and UCP1 were increased compared with WT. We compared several physiological parameters between WT and aox1a. Low‐temperature treatment did not result in a visible phenotype to distinguish aox1a from WT. In aox1a, several antioxidant defence genes were induced, and the malondialdehyde content was lower than in WT. Starch content and a ratio of carbon to nitrogen were higher in aox1a than in WT. Our results indicate that a lack of AOX was linked to a difference in the carbon and nitrogen balance, and an up‐regulation of the transcription of antioxidant defence system at low temperature. It is likely that AOX is a necessary component in antioxidant defence mechanisms and for the control of a balanced metabolism.
Determining the origin of soft‐sediment deformation structures: a case study from Upper Carboniferous delta deposits in south‐west Wales, UK
Authors: Owen Geraint , Moretti Massimo 
Published: May 2008

AbstractDetermining the cause of sediment mobilization is a major problem; possible triggers include earthquakes, sediment loading and wave action. A detailed sedimentological and palaeoenvironmental analysis of soft‐sediment deformation in Upper Carboniferous deltaic deposits in SW Wales, UK, shows that two styles of deformation occur. Type A (syndepositional convolute stratification) affects most sandstone beds and was generated by rapid sedimentation. Type B (localized sand‐in‐sand pseudonodules) incorporates beds that already contained Type A deformation, and developed when the substrate was liquefied by disturbance due to movement on a near‐surface gravity slide. Neither type of deformation was triggered by seismic events.
Alteration geochemistry of the Nopal I uranium deposit (Sierra Peña Blanca, Mexico), a natural analogue for a radioactive waste repository in volcanic tuffs
Authors: Calas Georges , Agrinier Pierre , Allard Thierry , Ildefonse Philippe 
Published: May 2008

AbstractNatural analogues provide an approach to characterize and test the long‐term modelling of a repository performance. This article presents geochemical information about the alteration conditions of the Nopal I uranium deposit, Mexico, an analogue for the proposed Yucca Mountain radioactive waste repository. Mineralization and hydrothermal alteration of volcanic tuffs are contemporaneous, according to petrographic observations. Trace element geochemistry (U, Th, REE) provides evidence for local mobilization of uranium under oxidizing conditions and further precipitation under reducing conditions. O‐ and H‐isotope geochemistry of kaolinite, smectite, opal and calcite suggests that argillic alteration proceeded at shallow depth with meteoric water at 25–75 °C, a low‐temperature context, unusual for volcanic‐hosted uranium deposits. This temperature range is compatible with some post‐closure evolution models of the proposed Yucca Mountain repository.
Cenozoic denudation in the Marrakech High Atlas, Morocco: insight from apatite fission‐track thermochronology
Authors: Missenard Yves , Saddiqi Omar , Barbarand Jocelyn , Leturmy Pascale , Ruiz Geoffrey , El Haimer Fatima‐Zahra , Frizon de Lamotte Dominique 
Published: May 2008

AbstractIn North Africa, the High Atlas belt culminates at more than 4000 m. In Morocco, recent work shows that a lithospheric thinning explains about 1000 m of the mean topography, the remaining topography being related to crustal shortening. We combine regional geology with new apatite fission‐track (AFT) ages to constrain the timing of these events in the Marrakech High Atlas (MHA). In the inner belt, 10 AFT ages are comprised between 9 ± 1 and 27 ± 3 Ma. These Neogene ages indicate that the MHA underwent significant denudation during that time. In the southern foreland domain of the belt, three samples give scattered AFT ages between 27 ± 2 and 87 ±5 Ma. Geological evidences allow us to constrain the age of a major denudation event during Middle Miocene age. We propose that it is linked to the thermal doming highlighted in the whole Moroccan Atlas domain.
CLINICAL STUDY: Lack of effect of chronic dextromethorphan on experimental pain tolerance in methadone‐maintained patients
Authors: Compton Peggy A. , Ling Walter , Torrington Matt A. 
Published: May 2008

ABSTRACTGood evidence exists to suggest that individuals on opioid maintenance for the treatment of addiction (i.e. methadone) are less tolerant of experimental pain than are matched controls or ex‐opioid addicts, a phenomenon theorized to reflect opioid‐induced hyperalgesia (OIH). Agonist activity at the excitatory ionotropic N‐methyl‐D‐aspartate (NMDA) receptor on dorsal horn neurons has been implicated in the development of both OIH and its putative expression at the clinical level—opioid tolerance. The aim of this study was to evaluate the potential utility of the NMDA‐receptor antagonist, dextromethorphan (DEX), to reverse or treat OIH in methadone‐maintenance (MM) patients. Utilizing a clinical trial design and double‐blind conditions, changes in pain threshold and tolerance [cold pressor (CP) and electrical stimulation (ES)] following a 5‐week trial of DEX (titrated to 480 mg/day) in comparison with placebo was evaluated in a well‐characterized sample of MM patients. The sample (n = 40) was 53% male and ethnically diverse (53% Latino, 28% African American, 10% White, 9% other), with a mean age of 48.0 years (SD = 6.97). Based ont‐test analyses, no difference was found between groups on CP pain threshold, CP pain tolerance, ES pain threshold or ES pain tolerance, both pre‐ and postmedication. Notably, DEX‐related changes significantly differed by gender, with women tending to show diminished tolerance for pain with DEX therapy. These results support that chronic high‐dose NMDA antagonism does not improve tolerance for pain in MM patients, although a gender effect on DEX response is suggested.
A specific mixture of short‐chain galacto‐oligosaccharides and long‐chain fructo‐oligosaccharides induces a beneficial immunoglobulin profile in infants at high risk for allergy
Authors: Van Hoffen E. , Ruiter B. , Faber J. , M'Rabet L. , Knol E.F. , Stahl B. , Arslanoglu S. , Moro G. , Boehm G. , Garssen J. 
Published: May 2008

Background:  It has been suggested that human breast milk oligosaccharides play a role in the development of the immune system in infants, and may consequently inhibit the onset of allergy. A specific prebiotic mixture of short‐chain galacto‐oligosaccharides and long‐chain fructo‐oligosaccharides (GOS/FOS) has been shown to reduce the incidence of atopic dermatitis (AD) at 6 months of age in infants at risk for allergy.Aim of the study:  This study was aimed to analyze the effect of GOS/FOS on the immune response in these infants.Methods:  In a double‐blind randomized placebo‐controlled study, infants received a hypoallergenic whey formula with either 8 g/l GOS/FOS in a 9 : 1 ratio (IMMUNOFORTISTM) or 8 g/l maltodextrine (placebo) for 6 months. At 3 months of age, children were vaccinated with Hexavac against a.o. diphteria, tetanus, polio (DTP). At 6 months of age, plasma samples were collected from 84 infants (verum group n = 41, placebo group n = 43). Levels of total immunoglobulins (Ig) and of cow’s milk protein (CMP‐) and DTP‐specific Ig were measured.Results:  GOS/FOS supplementation led to a significant reduction in the plasma level of total IgE, IgG1, IgG2 and IgG3, whereas no effect on IgG4 was observed. CMP‐specific IgG1 was significantly decreased. DTP‐specific Ig levels were not affected.Conclusions:  This study shows that GOS/FOS supplementation induces a beneficial antibody profile. GOS/FOS reduces the total Ig response and modulates the immune response towards CMP, while leaving the response to vaccination intact. This suggests that oral GOS/FOS supplementation is a safe method to restrain the atopic march.
Sputum neurokinin A in Egyptian asthmatic children and adolescents: relation to exacerbation severity
Authors: Mostafa G. A. , Reda S. M. , Abd El‐Aziz M. M. , Ahmed S. A. 
Published: May 2008

Background:  Neurogenic inflammation may participate in the development and progression of bronchial asthma. The molecular mechanisms underlying neurogenic inflammation are orchestrated by a large number of neuropeptides including tachykinins such as neurokinin A (NKA) and substance P. Tachykinins are secreted from sensory airway nerves and inflammatory cells after allergens exposure. In clinical practice, assessment of airway inflammation is difficult. Therefore, detection of biological markers of airway inflammation in sputum might offer help for proper monitoring of asthma severity.Aim of the study:  We aimed to measure sputum NKA in relation to acute asthma exacerbations of varying severity.Methods:  Sputum NKA was measured by enzyme‐linked immunosorbent assay in 24 children and adolescents during and after acute asthma exacerbation and 24 healthy matched controls.Results:  Sputum NKA was significantly higher in asthmatic patients during acute exacerbation than controls [217.5 (284) vs 10 (7) ng/ml, P < 0.001]. When patients with acute asthma exacerbation were followed‐up till remission, sputum NKA levels decreased significantly, but they remained significantly higher than controls. Sputum NKA levels were significantly higher in severe than moderate and in moderate than mild exacerbations, and was negatively correlated to peak expiratory flow rate (r = −0.9, P < 0.001). Sputum NKA had significant positive correlations to eosinophil counts in blood and sputum (r = 0.6, P < 0.001 and r = 0.7, P < 0.001 respectively).Conclusions:  Sputum NKA is up‐regulated during acute asthma exacerbation and it positively correlates to its severity. Thus, NKA may aid in objective classification of the exacerbation severity. In addition, NKA may be a target for new asthma therapy.
Effects of bio‐pesticides on Eretmocerus warrae (Hym., Aphelinidae), a parasitoid of Bemisia tabaci (Hom., Aleyrodidae)
Authors: Kumar P. , Whitten M. , Thoeming G. , Borgemeister C. , Poehling H.‐M. 
Published: May 2008

AbstractThe sweet potato whitefly Bemisia tabaci (WF) can be controlled by two commercial neem products, NeemAzal‐T/S® (1% azadirachtin) for foliar application, and NeemAzal‐U (17% azadirachtin) for soil application, alongwith two biorational products of microbial origin, Abamectin (avermectin) and Success® (spinosad). Side effects of these products were tested in a laboratory bioassay against a native aphelinid, Eretmocerus warrae (EW). Eggs and early larval instars of the parasitoid, commonly found outside the host body, were highly susceptible to foliar spray of neem with only 8%, 18% and 55% emergences of adults from treated eggs. larval and pupal stages respectively at recommended dose‐rates of 5 ml/l and 1%, 8% and 40% at twice recommend dose‐rate (10 ml/l). Soil application with NeemAzal‐U marginally affected EW. At highest tested dose‐rate of 3.0 g/l, 46%, 64% and 81% emergence was recorded after treatement of plants harbouring WF parasitized by egg, larval and pupal stages of EW respectively. In contrast to neem application, Success® and Abamectin caused high mortality in development stages of the parasitoids. In particular, abamectin was highly toxic to the parasitoids with less than 1% emergence from either of the three development stages if treated with 1–2 ml/l.
Effects of nutrients on feeding activities of the pest termite Heterotermes tenuis (Isoptera: Rhinotermitidae)
Authors: Haifig I. , Costa‐Leonardo A. M. , Marchetti F. F. 
Published: May 2008

Abstract Heterotermes tenuis is a native termite of large negative impact on the Brazilian economy. Many studies have focused on optimizing the baiting method for termite control by improving its use and its efficacy. In order to maximize termite bait consumption, this study aimed to select nutrient solutions which are able to enhance termite feeding. The effects of some sugars and urea on feeding preference of the subterranean termite H. tenuis were determined by double choice feeding tests, and the consumption was evaluated by variation in dry mass of filter paper after 28 days of termite feeding. Most of the solutions tested did not significantly influence feeding of H. tenuis. Termites fed preferentially on filter paper treated with 0.03 g/ml trehalose and 0.015 g/ml urea solutions. The data indicate that trehalose and urea solutions are phagostimulants to H. tenuis, and their future use in bait matrices may increase consumption of baits and improve this control technique.
Diversity analysis for resistance of rice (Oryza sativa L.) to blast disease [Magnaporthe grisea (Hebert) Barr.] using differential isolates from the Philippines
Authors: Telebanco‐Yanoria M. J. , Ohsawa R. , Senoo S. , Kobayashi N. , Fukuta Y. 
Published: May 2008

AbstractA wide variation in resistance to blast disease caused by Magnaporthe grisea (Hebert) Barr. (Rossman et al. 1992) was found using 922 rice (Oryza sativa L.) varieties collected mainly from Asia. These were classified into six varietal groups, termed clusters A–F, according to Ward’s hierarchical cluster analysis, based on the reaction pattern to 20 standard differential blast isolates from the Philippines. The most susceptible two clusters, B and C, dominated in varieties from the Far East (Japan). Varieties from East Asia and Southeast Asia occurred less frequently in B and C clusters than those of Japan, and more frequently in E and F clusters, which were the most resistant of the cluster groups. Varieties from South Asia showed the widest variation, occurring in all clusters but less frequently in cluster B. The cluster B varieties dominated in Japan and showed a high frequency of isozyme type VI, corresponding to Japonica type. In contrast, the frequency of cluster B was low in the groups with isozyme types I, II, III and V, which dominated in South Asia. Isozyme type I corresponds to Indica type varieties. The distribution of resistance corresponded to the geographical distribution of rice varieties and might be related to differentiation into Indica and Japonica types. These findings will provide useful information for understanding the variation in blast resistance at the global level.
Assessment of the resistance of cotton germplasm (Gossypium spp.) to aphids (Homoptera, Aphididae) and leafhoppers (Homoptera: Cicadellidae, Typhlocybinae): methodology and genetic variability
Authors: Nibouche S. , Brévault T. , Klassou C. , Dessauw D. , Hau B. 
Published: May 2008

AbstractWe carried out an assessment of the resistance of 71 accessions of cotton (Gossypium spp. L.) to the aphid Aphis gossypii and to leafhoppers under natural infestation. Our objectives were (i) to improve the methods for screening cotton germplasm for resistance to both pests, and (ii) to test the existence of genetic correlation between resistances to both insects. For both insects, the percentage of colonized leaves exhibited high genotypic correlation with the number of insects per leaf, had similar or higher heritabilities, and appeared as the better measure of insect populations. The one‐plant‐per‐plot experimental design used allowed an assessment of resistance with high heritability value, and proved to be suitable for the screening of cotton germplasm. G. arboreum was more resistant to both insects than G. barbadense and G. hirsutum. While hairiness had a significant negative effect on resistance to aphids, no significant effect was observed on resistance to leafhoppers, excepted in G. arboreum. The lack of genotypic correlation between resistance to aphids and to leafhoppers demonstrated that a simultaneous improvement of the resistance is possible.