bluuebunny/crossref_metadata_2025_split huggingface dataset:
The first zygotic division in Arabidopsis requires de novo transcription of thymidylate kinase
Authors: Ronceret Arnaud , Gadea‐Vacas Jose , Guilleminot Jocelyne , Lincker Frédéric , Delorme Valérie , Lahmy Sylvie , Pelletier Georges , Chabouté Marie‐Edith , Devic Martine 
Published: February 2008

SummaryRe‐activation of cell division after fertilization involves the specific regulation of a set of genes. To identify genes involved in the gametophytic to sporophytic transition, we screened Arabidopsis T‐DNA insertion lines for early seed abortion at the zygote (zeus) or one‐cell embryo stages (cyclops), and characterized a sporophytic zygote‐lethal mutation, zeus1. ZEUS1 encodes a thymidylate kinase (AtTMPK) that synthesizes dTDP and is involved in the regulation of DNA replication. Unlike in yeast and animals, the single AtTMPK gene is capable of producing two proteins by alternative splicing; the longer isoform is targeted to the mitochondria, the shorter to the cytosol. Transcription of AtTMPK is activated during the G1/S‐phase transition of the cell cycle, similarly to yeast and mammalian orthologues. In AtTMPK:GUS plants, the reporter gene was preferentially expressed in cells undergoing division, but was not detected during the male and female gametophytic mitoses. GUS expression was observed in mature embryo sacs prior to fertilization, and this expression may indicate the time of synchronization of the gamete cell‐cycle phases. Identification of ZEU1 emphasizes the importance of control of the metabolism of DNA in the regulation of the G1/S‐phase transition at fertilization.
Regulation of the anthocyanin biosynthetic pathway by the TTG1/bHLH/Myb transcriptional complex in Arabidopsis seedlings
Authors: Gonzalez Antonio , Zhao Mingzhe , Leavitt John M. , Lloyd Alan M. 
Published: February 2008

SummaryIn all higher plants studied to date, the anthocyanin pigment pathway is regulated by a suite of transcription factors that include Myb, bHLH and WD‐repeat proteins. However, in Arabidopsis thaliana, the Myb regulators remain to be conclusively identified, and little is known about anthocyanin pathway regulation by TTG1‐dependent transcriptional complexes. Previous overexpression of the PAP1 Myb suggested that genes from the entire phenylpropanoid pathway are targets of regulation by Myb/bHLH/WD‐repeat complexes in Arabidopsis, in contrast to other plants. Here we demonstrate that overexpression of Myb113 or Myb114 results in substantial increases in pigment production similar to those previously seen as a result of over‐expression of PAP1, and pigment production in these overexpressors remains TTG1‐ and bHLH‐dependent. Also, plants harboring an RNAi construct targeting PAP1 and three Myb candidates (PAP2, Myb113 and Myb114) showed downregulated Myb gene expression and obvious anthocyanin deficiencies. Correlated with these anthocyanin deficiencies is downregulation of the same late anthocyanin structural genes that are downregulated in ttg1 and bHLH anthocyanin mutants. Expression studies using GL3:GR and TTG1:GR fusions revealed direct regulation of the late biosynthetic genes only. Functional diversification between GL3 and EGL3 with regard to activation of gene targets was revealed by GL3:GR studies in single and double bHLH mutant seedlings. Expression profiles for Myb and bHLH regulators are also presented in the context of pigment production in young seedlings.
ROXY1 and ROXY2, two Arabidopsis glutaredoxin genes, are required for anther development
Authors: Xing Shuping , Zachgo Sabine 
Published: February 2008

SummaryGlutaredoxins (GRXs) are small oxidoreductases that are involved in various cellular processes and play a crucial role in responses to oxidative stress. Three GRX subgroups exist in plants, and GRXs with active sites of the CPYC and CGFS types are common to pro‐ and eukaryotes. In contrast, GRXs with the CC type motif have so far only been identified in land plants. Here, we report that the two CC‐type GRXs ROXY1 and ROXY2 together control anther development in Arabidopsis thaliana. Single roxy1 and roxy2 mutants are fertile and produce normal anthers. However, roxy1 roxy2 double mutants are sterile and do not produce pollen. Strikingly, abaxial and adaxial anther lobe differentiation are differently affected, with early lobe differentiation being defective in the adaxial lobes, whereas later steps during pollen mother cell differentiation are disrupted in the abaxial lobes. Expression studies show that ROXY1 and ROXY2 are expressed with overlapping patterns during anther development. Lack of ROXY1 and ROXY2 function affects a large number of anther genes at the transcriptional level. Genetic and RT‐PCR data imply that ROXY1/2 function downstream of the early‐acting anther gene SPOROCYTELESS/NOZZLE and upstream of DYSFUNCTIONAL TAPETUM1, controlling tapetum development. Mutagenesis of a conserved glutathione‐binding glycine in the ROXY1 protein indicates that CC‐type GRXs need to interact with glutathione to catalyze essential biosynthetic reactions. Analysis of these two novel anther genes indicates that redox regulation, as well as participating in plant stress defense mechanisms, might play a major role in the control of male gametogenesis.
SKP2A, an F‐box protein that regulates cell division, is degraded via the ubiquitin pathway
Authors: Jurado Silvia , Díaz‐Triviño Sara , Abraham Zamira , Manzano Concepción , Gutierrez Crisanto , Pozo Carlos del 
Published: February 2008

SummaryCoordination between cell division and cell differentiation is crucial for growth and development of eukaryotic organisms. Progression through the different phases of cell division requires the specific degradation of proteins through the ubiquitin/proteasome 26S (Ub/26S) pathway. In plants, this pathway plays a key role in controlling several developmental processes and responses, including cell proliferation. SKP2A, an F‐box protein, regulates the stability of the cell division E2FC‐DPB transcription factor. Here, we show that the SKP2A forms a Skp, Cullin containing (SCF) complexin vivo that has E3 ubiquitin ligase activity. Interestingly, SKP2A is degraded through the Ub/26S pathway, and auxin regulates such degradation. SKP2A positively regulates cell division, at least in part by degrading the E2FC/DPB transcription repressor. Plants that overexpress SKP2A increase the number of cells in G2/M, reduce the level of ploidy and develop a higher number of lateral root primordia. Taken together, our results indicate that SKP2A is a positive regulator of cell division, and its stability is controlled by auxin‐dependent degradation.
New insights into the identity and origin of the causal agent of oak powdery mildew in Europe
Authors: Mougou A. , Dutech C. , Desprez‐Loustau M.‐L. 
Published: February 2008

SummaryPowdery mildew is the most common disease on oaks in Europe where it was first recorded at the beginning of the 20th century. Yet, little is known about the origin of the causal agent. In this study, we analysed the variability of the ribosomal DNA (rDNA) of the pathogen. The internal transcribed spacer (ITS) region, the 5.8S rRNA coding gene and the intergenic spacer (IGS) of the rDNA of 33 European (mostly French) samples of oak powdery mildew were amplified using polymerase chain reaction (PCR) and PCR products were subsequently sequenced. Four different haplotypes were obtained for ITS among the various samples (ITSA, ITSB, ITSC and ITSD). Each ITS sequence corresponded to a different IGS sequence. The comparison of ITS sequences obtained with sequences accessible in the GenBank database revealed very high homologies with different taxa. Of these, three taxa had already been described on oaks in Europe, i.e. Erysiphe alphitoides (100% homology with ITSA), Erysiphe hypophylla (99.4% homology with ITSC) and Phyllactinia guttata (97.64% homology with ITSD). Our data also confirmed the 100% homology between ITSA and the sequence described for Oïdium mangiferae, the agent of mango powdery mildew. The fourth haplotype, i.e. ITSB, represented by nearly 25% samples, showed 100% homology with the recently described Erysiphe quercicola from Quercus spp. in Asia, and several tropical and sub‐tropical powdery mildew species, including Oïdium heveae, a major pathogen of rubber trees worldwide. Our results suggest that oak powdery mildew might originate from host shifts of tropical Erysiphe species introduced to Europe through infected exotic host plants.
Duration of erectile dysfunction and its relationship to treatment seeking and satisfaction with treatment using PDE5 inhibitors
Authors: Matic Hayley , McCabe Marita P 
Published: February 2008

Objectives: This cross‐sectional study was designed to evaluate whether the duration of erectile dysfunction (ED) influenced treatment seeking and satisfaction with treatment using PDE5 inhibitors.Methods: Participants were 409 men with ED who were primarily recruited over the internet via men's health web sites. Participants completed a questionnaire to assess the duration and perceived severity of ED, information and help‐seeking behaviors for ED, and treatment usage and satisfaction with PDE5 inhibitor medication.Results: The results demonstrated that men with ED of longer duration were more likely to have discussed their ED with their partner and doctor and to have sought information and treatment for their ED problem. No differences were found in reported satisfaction with ED medication usage or expected future medication use across the varying levels of ED duration, once variance attributable to age was accounted for.Conclusions: These results suggest that men are more likely to accept that they have ED and seek treatment for their ED with increasing duration of the condition, although these men are not more satisfied with PDE5 inhibitors as a treatment option.
HETEROGENEOUS CAPITAL GOODS AND THE HARROD–BALASSA–SAMUELSON EFFECT
Authors: Mariolis Theodore 
Published: February 2008

ABSTRACTThis paper shows that in a world of ‘production of commodities by means of commodities’ there is not an unambiguous relation between the long‐period relative commodity prices and the sectoral total factor productivities. Consequently, the Harrod–Balassa–Samuelson effect is not verified and/or makes no sense.
Dopamine‐induced toxicity is synergistically potentiated by simultaneous HSP‐90 and Akt inhibition in oligodendrocyte progenitors
Authors: Hemdan Sandy , Almazan Guillermina 
Published: February 2008

AbstractOligodendrocyte progenitors are highly susceptible to various insults. Their limited antioxidant defenses and high levels of apoptotic factors, such as Bax and pro‐caspase‐3 contribute to their sensitivity. We previously showed that dopamine (DA) is toxic to oligodendrocyte progenitors by inducing superoxide generation, lowering glutathione levels and promoting apoptosis through caspase‐3 activation. In contrast, factors that contribute to cell survival and defense against dopamine (DA) toxicity are less studied. Here, we explored the role of two molecules which play important roles in cell survival, namely the heat shock protein 90 (HSP‐90) and the protein kinase Akt, using the selective inhibitors, 17‐AAG and Akt inhibitor III, respectively. The HSP‐90 inhibitor caused a decrease in P‐Akt level, induced caspase‐3 activation, increased nuclear condensation and caused a loss in cell viability. Furthermore, 17‐AAG potentiated DA‐induced apoptosis by enhancing caspase‐3 activation. In addition, the Akt inhibitor alone exacerbated DA toxicity and in combination with 17‐AAG caused synergistic potentiation of DA toxicity by enhancing caspase‐3 activation. Together, these results indicate that HSP‐90 is essential for oligodendrocyte progenitor survival. Both HSP‐90 and Akt play important roles in concert in the defense against DA‐induced apoptosis.
A dyadic assessment of how couples indicate their commitment to each other
Authors: WEIGEL DANIEL J. 
Published: February 2008

AbstractThis study investigated the behaviors couples use to indicate their commitment in romantic relationships and explored the complex ways in which these behaviors are interconnected. Survey data were collected from 121 romantically involved couples in the United States. Dyadic analysis of the data revealed that the greater the levels of commitment, the more frequent the use of certain behaviors to indicate commitment. In addition, couples were similar in their use of the indicators, tended to project their self‐perceptions onto their partners, and had a degree of accuracy in perceiving their partners’ use of indicators. The research sheds light on some of the complex ways intimate couples experience and express commitment in the everyday lives.
Commitment expectations in romantic relationships: Application of a prototype interaction‐pattern model
Authors: HAMPEL ALEXA D. , VANGELISTI ANITA L. 
Published: February 2008

AbstractThree studies were conducted to investigate whether commitment expectations in romantic relationships can be described using a prototype interaction‐pattern model of interpersonal expectations. Participants included male and female students enrolled at a university in the United States. In Study 1, 204 participants listed interaction patterns they believed produce a sense of commitment in romantic relationships. Study 2 (N= 170) tested whether the patterns are organized around prototypes, such that some patterns are more likely to create a sense of commitment than others. In Study 3, 160 participants evaluated the effects of prototypical and nonprototypical pattern violations to verify the prototype structure further. The utility of the prototype interaction‐pattern model for analyzing commitment expectations was supported in all 3 studies.
Addressing genetic heterogeneity in complex disease: Finding seizure genes in systemic lupus erythematosus
Authors: Bautista Jocelyn F. , Kelly Jennifer A. , Harley John B. , Gray‐McGuire Courtney 
Published: February 2008

Summary Complex genetic disease is inherently difficult to study due to an imperfect relationship between genotype and phenotype. One important reason for this imperfect relationship is genetic heterogeneity, the occurrence of different genetic factors underlying the same clinical syndrome. One method of addressing genetic heterogeneity is covariate‐based linkage analysis, which allows the use of additional phenotypic features to define genetically distinct subsets of patients. Systemic lupus erythematosus (SLE) is one example of a complex genetic disease affecting multiple organ systems including the central nervous system. We report here the use of covariate‐based linkage analysis to detect a potential genetic locus on chromosome 15 influencing the development of seizures in individuals with SLE. The use of covariates increases the power to detect linkage in the presence of genetic heterogeneity.
Exploring Pregnancy‐Related Changes in Alcohol Consumption Between Black and White Women
Authors: Morris Daniel S. , Tenkku Leigh E. , Salas Joanne , Xaverius Pamela K. , Mengel Mark B. 
Published: February 2008

Background:  Although epidemiological data indicate that White women are more likely to drink and binge drink before pregnancy, fetal alcohol syndrome (FAS) is more common in the Black population than among Whites in the United States. Differences in drinking cessation between Black and White women who become pregnant may help explain the disparity in FAS rates.Methods:  The study sample was comprised of 280,126 non‐Hispanic Black and White women, ages 18 to 44, from the Behavioral Risk Factor Surveillance System (BRFSS) 2001 to 2005 data sets. Predictors of reduction in alcohol consumption (in drinks per month) and binge drinking (>4 drinks on one occasion) by pregnant and non‐pregnant women were identified with logistic regression. The effect of interactions of pregnancy status with age, education, and Black or White race on drinks per month and binge occasions were explored using analysis of variance (ANOVA).Results:  Pregnant White women averaged 79.5% fewer drinks per month than non‐pregnant White women (F = 1250.1, p < 0.001), and 85.4% fewer binge drinking occasions (F = 376, p < 0.001). Pregnant Black women averaged 58.2% fewer drinks per month than non‐pregnant Black women (F = 31.8, p < 0.001) and 64.0% fewer binge occasions (F = 13.8, p < 0.001). Compared to Black women, White women appear to make a 38% greater reduction in drinks per month, and a 33% greater reduction in binge occasions.Conclusions:  Non‐Hispanic White women appear more likely to reduce drinks per month and binge drinking occasions than non‐Hispanic Black women during pregnancy. These findings may help explain disparities in FAS in the United States, though this cross‐sectional sample does not permit claims of causation. To better describe the impact of differential drinking reduction on FAS rates, future studies of longitudinal data should be done.
Perioperative management of aspirin resistance after off‐pump coronary artery bypass grafting: possible role for aprotinin
Authors: Poston Robert S. , Gu Junyan , White Charles , Jeudy Jean , Nie Lei , Brown James , Gammie James , Pierson Richard N. , Romar Linda , Griffith Bartley P. 
Published: February 2008

BACKGROUND: Aspirin is the only drug proven to reduce saphenous vein graft (SVG) failure, but aspirin resistance (ASA‐R) frequently occurs after off‐pump coronary artery bypass grafting (OPCAB). The factors, mechanism, and best means for preventing and/or treating ASA‐R have not been established. This study hypothesizes that thrombin production during OPCAB stimulates this acquired ASA‐R.STUDY DESIGN AND METHODS: A nonrandomized prospective cohort of 255 patients (n = 465 SVG) who underwent OPCAB with varied use of aprotinin (21%) and different SVG preparation techniques (standard, 56% vs. low‐pressure, 44%) was analyzed. A surplus SVG segment was obtained to assess endothelial integrity. ASA‐R was determined at baseline, after surgery, and on Days 1 and 3 by three assays. The effects of aprotinin on thrombin responsiveness were analyzed by means of whole‐blood aggregometry, SVG tissue factor (TF) activity, and transcardiac thrombin production (i.e., F1.2 levels in aorta versus coronary sinus). SVG patency was assessed on Day 5 with multichannel CT angiography.RESULTS: ASA‐R developed in 42 percent of patients after OPCAB. Multivariate analysis showed that ASA‐R, endothelial integrity, and target size independently predicted early SVG failure. Aprotinin use was associated with: 1) reduced postoperative ASA‐R (15%); 2) decreased platelet (PLT) response to thrombin; 3) reduced TF activity within SVG segments; 4) decreased transcardiac thrombin gradient; and 5) improved SVG patency.CONCLUSION: ASA‐R is a common post‐OPCAB event whose frequency may be reduced by intraoperative use of aprotinin, possibly via TF and thrombin suppression. Improved perioperative PLT function after OPCAB may also inadvertently enhance the clinical relevance of these potential antithrombotic effects.
Sensing Failure Associated with the Medtronic Sprint Fidelis Defibrillator Lead
Authors: KENIGSBERG DAVID N. , MIRCHANDANI SUNIL , DOVER AMANDA N. , KOWALSKI MARCIN , WOOD MARK A. , SHEPARD RICHARD K. , KALAHASTY GAUTHAM , STEIN KENNETH M. , MARKOWITZ STEVEN M. , IWAI SEI , SHAH BINDI K. , LERMAN BRUCE B. , MITTAL SUNEET , ELLENBOGEN KENNETH A. 
Published: February 2008

Introduction: The diameter of implantable cardioverter‐defibrillator (ICD) leads has become progressively smaller over time. However, the long‐term performance characteristics of these smaller ICD leads are unknown. Methods: We retrospectively evaluated 357 patients who underwent implantation of a Medtronic Sprint Fidelis™ defibrillating lead at two separate centers between September 2004 and October 2006. Lead characteristics were measured at implant, at early follow‐up (1–4 days post implant), and every 3–6 months thereafter. Results: During the study period, 357 patients underwent implantation of the Medtronic Sprint Fidelis™ lead. The mean R‐wave measured at implant through the device was not different (P = NS) when compared with that measured at first follow‐up (10.5 ± 5.0 mV vs 10.7 ± 5.1 mV). Forty‐one patients (13%) had an R‐wave amplitude ≤ 5 mV measured through the device at implant. Of those patients with an R‐wave amplitude ≤ 5 mV at implant measured through the device, 63% (n = 26) remained ≤ 5 mV for the duration of follow‐up. The mean time to R‐wave amplitude ≤ 5 mV was 96.2 ± 123 days. During follow‐up, 65 (18%) patients developed R‐wave ≤ 5 mV. Overall 10 lead revisions (2.8%) were performed during the first year of follow‐up. Conclusion: Abnormal R‐wave sensing is frequently observed during follow‐up with the Medtronic Fidelis ICD lead. Lead revision was necessary in 2.8% of the patients, most often (8 of 10) due to abnormal R‐wave sensing along with elevated pacing threshold. Whether this issue is limited to this lead or reflects a potential problem with all downsized ICD leads merits further investigation.
A systematic review and meta‐analyses on C‐reactive protein in relation to periodontitis
Authors: Paraskevas Spiros , Huizinga John D. , Loos Bruno G. 
Published: February 2008

AbstractAim: Elevated plasma C‐reactive protein (CRP) is regarded as a risk predictor for cardiovascular diseases. This systematic review explored the robustness of observations that CRP is elevated in periodontitis. Similarly, the effect of periodontal therapy on CRP levels was investigated.Material and Methods: Selection of publications was based on: (1) cross‐sectional (case–control) studies; (2) longitudinal (treatment) studies; (3) high‐sensitivity CRP measurement; (4) median and/or mean (±SD) values presented; and (5) subjects with no systemic disorders.Results: Screening of the initially 448 identified studies and reference checking resulted in 18 suitable papers. The majority of the studies showed that CRP levels are higher in patients than in controls. Often, studies showed that patients had CRP levels >2.1 mg/l. A meta‐analysis of 10 cross‐sectional studies showed that the weighted mean difference (WMD) of CRP between patients and controls was 1.56 mg/l (p<0.00001). Evidence from available treatment studies (n=6) showed lower levels of CRP after periodontal therapy. Eligible treatment studies in a meta‐analysis demonstrated a WMD of reductions of CRP after therapy of 0.50 mg/L (95% CI 0.08–0.93) (p=0.02).Conclusions: There is strong evidence from cross‐sectional studies that plasma CRP in periodontitis is elevated compared with controls. There is modest evidence on the effect of periodontal therapy in lowering the levels of CRP.
Effect of glycine powder air‐polishing on the gingiva
Authors: Petersilka Gregor , Faggion Clovis Mariano , Stratmann Udo , Gerss Joachim , Ehmke Benjamin , Haeberlein Ingo , Flemmig Thomas F. 
Published: February 2008

AbstractObjectives: Safety and efficacy of glycine powder air‐polishing (GPAP) in removing subgingival biofilm have been previously demonstrated. The hypothesis that GPAP results in less gingival erosion than sodium bicarbonate air‐polishing (SBAP) or hand‐instrumentation was assessed.Material and Methods: In each of 10 patients, eight teeth with a residual probing depth of at least 5 mm following initial periodontal therapy were randomly assigned to the following interventions: GPAP (test), SBAP (positive control), hand‐instrumentation (positive control), or no treatment (negative control). In each group, gingival biopsies were taken immediately after instrumentation and one 14 days later. Damaged gingival epithelium (GE) was assessed by light microscopy and quantified by a histological score (values 1–4). Differences between groups were evaluated using the marginal homogeneity test.Results: GPAP resulted in minor erosions of the GE (scores 1 and 2), whereas positive control specimens displayed moderate to severe erosions (scores 2–4). Differences between GPAP and positive controls were significant (p<0.05). Fourteen days following instrumentation GE under assessment was found to be intact in all groups.Conclusion: The data indicated that GPAP results in less gingival erosion than SBAP or hand instrumentation, further supporting the safety of this new debridement technique.