bluuebunny/crossref_metadata_2025_split huggingface dataset:
Participation of Endomembrane Cation/H+ Exchanger AtCHX20 in Osmoregulation of Guard Cells
Authors: Padmanaban Senthilkumar , Chanroj Salil , Kwak June M. , Li Xiyan , Ward John M. , Sze Heven 
Published: March 2007

AbstractGuard cell movement is induced by environmental and hormonal signals that cause changes in turgor through changes in uptake or release of solutes and water. Several transporters mediating these fluxes at the plasma membrane have been characterized; however, less is known about transport at endomembranes. CHX20, a member of a poorly understood cation/H+ exchanger gene family in Arabidopsis (Arabidopsis thaliana), is preferentially and highly expressed in guard cells as shown by promoter∷β-glucuronidase activity and by whole-genome microarray. Interestingly, three independent homozygous mutants carrying T-DNA insertions in CHX20 showed 35% reduction in light-induced stomatal opening compared to wild-type plants. To test the biochemical function of CHX20, cDNA was expressed in a yeast (Saccharomyces cerevisiae) mutant that lacks Na+(K+)/H+ antiporters (Δnhx1 Δnha1 Δkha1) and plasma membrane Na+ pumps (Δena1-4). Curiously, CHX20 did not enhance tolerance of mutants to moderate Na+ or high K+ stress. Instead, it restored growth of the mutant on medium with low K+ at slightly alkaline pH, but had no effect on growth at acidic pH. Green fluorescent protein-tagged CHX20 expressed in mesophyll protoplasts was localized mainly to membranes of the endosomal system. Furthermore, light-induced stomatal opening of the Arabidopsis mutants was insensitive to external pH and was impaired at high KCl. The results are consistent with the idea that, in exchanging K+ for H+, CHX20 maintains K+ homeostasis and influences pH under certain conditions. Together, these results provide genetic and biochemical evidence that one CHX protein plays a critical role in osmoregulation through K+ fluxes and possibly pH modulation of an active endomembrane system in guard cells.
Molecular Modeling and Site-Directed Mutagenesis Reveal the Benzylisoquinoline Binding Site of the Short-Chain Dehydrogenase/Reductase Salutaridine Reductase
Authors: Geissler René , Brandt Wolfgang , Ziegler Jörg 
Published: March 2007

AbstractRecently, the NADPH-dependent short-chain dehydrogenase/reductase (SDR) salutaridine reductase (E.C. 1.1.1.248) implicated in morphine biosynthesis was cloned from Papaver somniferum. In this report, a homology model of the Papaver bracteatum homolog was created based on the x-ray structure of human carbonyl reductase 1. The model shows the typical α/β-folding pattern of SDRs, including the four additional helices αF′-1 to αF′-4 assumed to prevent the dimerization of the monomeric short-chain dehyrogenases/reductases. Site-directed mutagenesis of asparagine-152, serine-180, tyrosine-236, and lysine-240 resulted in enzyme variants with strongly reduced performance or inactive enzymes, showing the involvement of these residues in the proton transfer system for the reduction of salutaridine. The strong preference for NADPH over NADH could be abolished by replacement of arginine residues 44 and 48 by glutamic acid, confirming the interaction between the arginines and the 2′-phosphate group. Docking of salutaridine into the active site revealed nine amino acids presumably responsible for the high substrate specificity of salutaridine reductase. Some of these residues are arranged in the right position by an additional αE′ helix, which is not present in SDRs analyzed so far. Enzyme kinetic data from mutagenic replacement emphasize the critical role of these residues in salutaridine binding and provide the first data on the molecular interaction of benzylisoquinoline alkaloids with enzymes.
PlanTAPDB, a Phylogeny-Based Resource of Plant Transcription-Associated Proteins
Authors: Richardt Sandra , Lang Daniel , Reski Ralf , Frank Wolfgang , Rensing Stefan A. 
Published: March 2007

AbstractDiversification of transcription-associated protein (TAP) families during land plant evolution is a key process yielding increased complexity of plant life. Understanding the evolutionary relationships between these genes is crucial to gain insight into plant evolution. We have determined a substantial set of TAPs that are focused on, but not limited to, land plants using PSI-BLAST searches and subsequent filtering and clustering steps. Phylogenies were created in an automated way using a combination of distance and maximum likelihood methods. Comparison of the data to previously published work confirmed their accuracy and usefulness for the majority of gene families. Evidence is presented that the flowering plant apical stem cell regulator WUSCHEL evolved from an ancestral homeobox gene that was already present after the water-to-land transition. The presence of distinct expanded gene families, such as COP1 and HIT in moss, is discussed within the evolutionary backdrop. Comparative analyses revealed that almost all angiosperm transcription factor families were already present in the earliest land plants, whereas many are missing among unicellular algae. A global analysis not only of transcription factors but also of transcriptional regulators and novel putative families is presented. A wealth of data about plant TAP families and all data accrued throughout their automated detection and analysis are made available via the PlanTAPDB Web interface. Evolutionary relationships of these genes are readily accessible to the nonexpert at a mouse-click. Initial analyses of selected gene families revealed that PlanTAPDB can easily be exerted for knowledge discovery.
The N-Terminal Double-Stranded RNA Binding Domains ofArabidopsisHYPONASTIC LEAVES1 Are Sufficient for Pre-MicroRNA Processing
Authors: Wu Feijie , Yu Lin , Cao Wenguang , Mao Yanfei , Liu Zhongyuan , He Yuke 
Published: March 2007

AbstractArabidopsis thaliana HYPONASTIC LEAVES1 (HYL1) is a microRNA (miRNA) biogenesis protein that contains two N-terminal double-stranded RNA binding domains (dsRBDs), a putative nuclear localization site (NLS), and a putative protein–protein interaction domain. The interaction of HYL1 with DICER-LIKE1 is important for the efficient and precise processing of miRNA primary transcripts in plant miRNA biogenesis. To define the roles of the various domains of HYL1 in miRNA processing and the miRNA-directed phenotype, we transferred a series of HYL1 deletion constructs into hyl1 null mutants. The N-terminal region containing dsRBD1 and dsRBD2 completely rescued the mutant phenotype of hyl1, triggering the accumulation of miR166 and miR160 and resulting in reduced mRNA levels of the targeted genes. In vivo biochemical analysis of the HYL1-containing complexes from the transgenic plants revealed that the N-terminal dsRBDs of HYL1 were sufficient for processing miRNA precursors and the generation of mature miRNA. Transient and stable expression analysis demonstrated that the putative NLS domain was indeed the nuclear localization signal, whereas the N-terminal region containing the dsRBDs was not restricted to the nucleus. We suggest that the N-terminal dsRBDs fulfill the function of the whole HYL1 and thus play an essential role in miRNA processing and miRNA-directed silencing of targeted genes.
Single Gene–Mediated Shift in Pollinator Attraction inPetunia
Authors: Hoballah Maria Elena , Gübitz Thomas , Stuurman Jeroen , Broger Larissa , Barone Mario , Mandel Therese , Dell'Olivo Alexandre , Arnold Maeva , Kuhlemeier Cris 
Published: March 2007

AbstractAnimal-mediated pollination is essential in plant reproductive biology and is often associated with pollination syndromes, sets of floral traits, such as color, scent, shape, or nectar content. Selection by pollinators is often considered a key factor in floral evolution and plant speciation. Our aim is the identification and characterization of the genetic changes that caused the evolution of divergent pollination syndromes in closely related plant species. We focus on ANTHOCYANIN2 (AN2), a well-defined myb-type transcription factor that is a major determinant of flower color variation between Petunia integrifolia and Petunia axillaris. Analysis of sequence variation in AN2 in wild P. axillaris accessions showed that loss-of-function alleles arose at least five times independently. DNA sequence analysis was complemented by functional assays for pollinator preference using genetic introgressions and transgenics. These results show that AN2 is a major determinant of pollinator attraction. Therefore, changes in a single gene cause a major shift in pollination biology and support the notion that the adaptation of a flowering plant to a new pollinator type may involve a limited number of genes of large effect. Gene identification and analysis of molecular evolution in combination with behavioral and ecological studies can ultimately unravel the evolutionary genetics of pollination syndromes.
Modern management of haemophilic arthropathy
Authors: Leslie Raffini , Catherine Manno 
Published: March 2007

SummaryCurrently available factor concentrates for treatment of patients with haemophilia are virally inactivated or are made by recombinant technology and their broad use in developed nations has resulted in the dramatic elimination of the treatment‐related viral illnesses that decimated the haemophilia community in the late 20th century. The major morbidity experienced by patients with haemophilia today is joint disease, a result of repeated bleeding episodes into joint spaces. Although administration of factor concentrates to prevent bleeding has been demonstrated to prevent haemophilic joint disease when applied assiduously, repeated bleeding episodes induce synovitis that is irreversible and may progress despite subsequent prophylaxis. Surgical and nuclear medicine interventions are available to reduce the pain of haemophilic arthropathy and to reduce further bleeding episodes. Patients with high titre inhibitors are at great risk for the development of joint disease and present the greatest therapeutic challenges when joint surgery is needed.
The pathogenesis of transfusion‐related acute lung injury (TRALI)
Authors: Bux Jürgen , Sachs Ulrich J. H. 
Published: March 2007

SummaryIn recent years, transfusion‐related acute lung injury (TRALI) has developed from an almost unknown transfusion reaction to the most common cause of transfusion‐related major morbidities and fatalities. A clinical definition of TRALI was established in 2004, based on acute respiratory distress, non‐cardiogenic lung oedema temporal association with transfusion and hypoxaemia. Histological findings reveal lung oedema, capillary leucostasis and neutrophil extravasation. However, the pathogenesis of TRALI remains controversial. Leucocyte antibodies, present in fresh frozen plasma and platelet concentrates from multiparous donors, and neutrophil priming agents released in stored cellular blood components have been considered to be causative. As neutrophils and endothelial cells are pivotal in the pathogenesis of TRALI, a threshold model was established to try to unify the various reported findings on pathogenesis. This model comprises the priming of neutrophils and/or endothelium by the patient's co‐morbidity, neutrophil and/or endothelial cell activation by the transfused blood component, and the severity of the TRALI reaction.
Unexplained anaemia in older persons is characterised by low erythropoietin and low levels of pro‐inflammatory markers
Authors: Ferrucci Luigi , Guralnik Jack M. , Bandinelli Stefania , Semba Richard D. , Lauretani Fulvio , Corsi Annamaria , Ruggiero Carmelinda , Ershler William B. , Longo Dan L. 
Published: March 2007

SummaryEpidemiological studies report that a third of the cases of anaemia in older persons is unexplained. We compared erythropoietin (EPO), inflammatory markers and major comorbidities between older subjects with normal haemoglobin levels and those with different aetiologic forms of anaemia, including unexplained anaemia. Participants were a representative sample of 964 persons aged ≥65 years, with no evidence of bleeding, complete blood tests, and a complete blood count within 6 h of phlebotomy. Anaemia was defined as haemoglobin <130 g/l in men and 120 g/l in women, and classified as a result of chronic kidney disease, iron deficiency, chronic disease and B12/folate deficiency anaemia, or unexplained anaemia based on standard criteria. Of the 124 anaemic participants, 42 (36·8%) had unexplained anaemia. Participants with anaemia of chronic diseases had significantly higher interleukin‐6 (IL‐6) and C‐reactive protein (CRP) levels, while those with unexplained anaemia had significantly lower CRP than non‐anaemic controls. Iron deficiency anaemia was characterised by significantly higher EPO levels compared with other types of anaemia and normal haemoglobin, B12 and/or folate deficiency. Unexplained anaemia was characterised by unexpectedly low EPO and low lymphocyte count. Unexplained anaemia is associated with reduced kidney EPO response, low levels of pro‐inflammatory markers and low lymphocyte counts.
An interphase fluorescence in situ hybridisation assay for the detection of 3q26.2/EVI1 rearrangements in myeloid malignancies
Authors: Bobadilla Dolores , Enriquez Elmon L. , Alvarez Georgina , Gaytan Popsie , Smith David , Slovak Marilyn L. 
Published: March 2007

SummaryChromosome rearrangements involving band 3q26.2 are associated with myeloid malignancies, aberrant expression of the human ecotropic virus integration site‐1 (EVI1) gene, an unfavourable prognosis and an aggressive clinical course. The 3q26.2 rearrangements are characteristically heterogeneous and typically difficult to detect in poor quality metaphases. To develop a dual‐colour fluorescence in situ hybridisation (FISH) assay for the detection of 3q26.2/EVI1 aberrations, a series of 10 BAC clones corresponding to the EVI1 gene region were systematically evaluated and narrowed down to two probe sets; one probe set encompassed the EVI1 gene extending centromeric, while the second probe set covered the EVI1 gene and extends telomeric. Both probe sets were evaluated on 35 patient samples with cytogenetically defined 3q26.2 rearrangements collected at various treatment time points, the inv(3)(q21q26.2) Kasumi‐4 cell line, and 10 known negative samples. The two‐probe set strategy identified all samples, despite the vast breakpoint heterogeneity observed. In samples from acute myeloid leukaemia and myelodysplastic syndrome cases, the majority of inversion breakpoints were 3′ to EVI1 whereas 3q26.2 translocation breakpoints frequently mapped 5′ to EVI1. However, two 3q26.2 translocation samples had breakpoints 3′ to EVI1. Most inv(3q) chronic myeloid leukaemia samples showed breakpoints within the EVI1 gene. This study demonstrated that, despite the extensive breakpoint heterogeneity observed with 3q26.2 aberrations, this FISH strategy is effective for the detection of 3q26.2 abnormalities in myeloid malignancies.
A dose‐response study of hormone replacement in young hypogonadal women: effects on intima media thickness and metabolism
Authors: Ostberg Julia E. , Storry Clare , Donald Ann E. , Attar M Javad Hosseinzadeh , Halcox Julian P. J. , Conway Gerard S. 
Published: March 2007

SummaryObjective  Young hypogonadal women appear to have an increased risk of cardiovascular disease. We studied the influence of increasing doses of hormone replacement therapy (HRT) on markers of metabolism and vascular physiology.Design  Nine‐month sequential dose‐ranging study.Patients  A total of 25 young hypogonadal women (Turner Syndrome, n = 14; 46,XX gonadal dysgenesis, n = 9), hypogonadotrophic hypogonadism (n = 2), mean age 31·9 years (range 18·5–42·2). All subjects sequentially received oral 17β‐oestradiol 1,2 and 4 mg daily in a cyclical formulation for 12 weeks each.Measurements  Metabolic markers and vascular physiology measurements to assess intima media thickness (IMT); arterial stiffness: pulse wave velocity (PWV) and augmentation index (AIx); endothelial function: flow‐mediated dilatation (FMD).Results  Increasing doses of oestrogen resulted in a reduction in IMT (0·63 ± 0·06 vs. 0·58 ± 0·06 vs. 0·56 ± 0·06 mm at 1 mg, 2 mg and 4 mg 17β‐oestradiol, respectively, P = 0·001). Results were similar in women with Turner Syndrome and normal karyotype. High‐density lipoprotein (HDL) cholesterol concentrations increased (1·9 ± 0·4 vs. 2·0 ± 0·5 vs. 2·2 ± 0·4 mmol/l, P = 0·001) and plasma glucose (4·8 ± 0·4 vs. 4·7 ± 0·3 vs. 4·6 ± 0·6 mmol/l, P = 0·038) decreased slightly with the increasing dose of HRT. There was no correlation between the changes in IMT and HDL. Increasing HRT dose had no significant impact on blood pressure, weight, other lipid parameters, insulin, C‐reactive protein, interleukin‐6 and fibrinogen concentrations or FMD, PWV and AIx.Conclusions  Increasing doses of HRT result in a reduction in carotid IMT in young hypogonadal women, along with increased serum HDL and decreased plasma glucose. This study raises the possibility that exogenous oestrogen may be cardioprotective in young women, but this observation needs to be balanced against a prothrombotic effect which is predominant in postmenopausal women.
Lead ion adsorption on montmorillonite–Al hydroxide polymer systems
Authors: Janssen R. P. T. , Bruggenwert M. G. M. , Van Dijk G. , Van Riemsdijk W. H. 
Published: March 2007

SummaryClay–Al hydroxide polymer systems (CAlHO) can bind heavy metals effectively. Their adsorption behaviour depends on the type of metal. We studied the dependence of Al‐loading and pH on the adsorption of Pb to Na‐saturated montmorillonite–Al hydroxide polymer systems. The available binding sites on the Al hydroxide polymers (AlHO) had a strong affinity for Pb ions, whereas a minor amount of Pb was bound to the clay surface. The pH had a pronounced effect on the Pb binding to the AlHO. At pH 6.0, AlHO effectively adsorbed Pb. The amount of Pb adsorbed to the AlHO, expressed per mole Al, increased with increasing amount of AlHO fixed. Lead bound to the AlHO could easily be removed by exchange and is therefore reversibly bound to the AlHO. Probably, Pb is outer‐sphere bound to the AlHO and an electrostatic bonding mechanism is involved. At pH 5.0 there was almost no adsorption of Pb to the AlHO, and the adsorption of Pb to the clay surface was limited because Al3+ ions competed with Pb2+ for exchangeable sites. At pH 6.6 and relatively large Pb concentrations, separate precipitates of Pb(OH)2 and Al(OH)3 were formed. Results from experiments in pure clay systems suggest that the Pb(OH)2 precipitate was present as positively charged Pb polymers.
Stream ecosystem responses to spatially variable land cover: an empirically based model for developing riparian restoration strategies
Authors: JOHNSON THOMAS E. , MCNAIR JAMES N. , SRIVASTAVA PUNEET , HART DAVID D. 
Published: March 2007

Summary1. The restoration of native, forested riparian habitats is a widely accepted method for improving degraded streams. Little is known, however, about how the width, extent and continuity of forested vegetation along stream networks affect stream ecosystems.2. To increase the likelihood of achieving restoration goals, restoration practitioners require quantitative tools to guide the development of restoration strategies in different catchment settings. We present an empirically based model that establishes a relationship between a ‘stress’ imposed at different locations along a stream by the spatial pattern of land cover within catchments, and the response of biologically determined ecosystem characteristics to this stress. The model provides a spatially explicit, quantitative framework for predicting the effects of changes in catchment land cover composition and spatial configuration on specific characteristics of stream ecosystems.3. We used geospatial datasets and biological data for attached algae and benthic macroinvertebrates in streams to estimate model parameters for 40 sites in 33 distinct catchments within the mid‐Atlantic Piedmont region of the eastern U.S. Model parameters were estimated using a genetic optimisation algorithm. R2 values for the resulting relationships between catchment land cover and biological characteristics of streams were substantially improved over R2 values for spatially aggregated regression models based on whole‐catchment land cover.4. Using model parameters estimated for the mid‐Atlantic Piedmont, we show how the model can be used to guide restoration planning in a case study of a small catchment. The model predicts the quantitative change in biological characteristics of the stream, such as indices of species diversity and species composition, that would occur with the implementation of a hypothetical restoration project.
Nursing and medical documentation on patients’ cultural background
Authors: Gebru Kerstin , Åhsberg Elizabeth , Willman Ania 
Published: March 2007

Aims and objectives.  To investigate if, and to what extent, nursing and medical documentation in patient records include entries on cultural background.Background.  Health care professionals in Sweden may have difficulties in providing satisfactory care, due to lack of knowledge about immigrants’ background. According to Swedish law the information needed to guarantee safe care must be specified in the patients’ records. It is, therefore, important to investigate what information nurses and physicians document on patients’ cultural background.Design and methods.  In this descriptive study, archival data concerning older and terminally ill patients were analysed retrospectively. The sample consisted of records from 121 patients ≥65 years at the time of death, who were born abroad and died during the year 1999. Content analysis was used to interrogate data collected from patient records, which related to the patient's cultural background. Entries (sentences or portion of sentences) were identified, coded and categorized using Leininger's Sunrise Model.Results.  From the patient records, entries could be related to all the factors in the upper part of the Sunrise Model. Some factors were found in all records, and all factors, except technological factors, could be traced across the patients’ records. Information concerning folk/lay care could not be found.Conclusions.  The results from this study indicate that nurses’ and physicians’ documentation in patient records included all factors in the Sunrise Model except technological. The overall impression is that the documentation is partly atomistic and insufficient as cultural assessment.Relevance to clinical practice.  Even if the health care personnel want to reduce the amount of documentation produced, this study highlighted the importance of documentation on cultural factors. To save time the nursing documentation could be based on the Sunrise Model and structured according to the VIPS model.