bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Expression of the t-SNARE AtSNAP33 Is Induced by Pathogens and Mechanical Stimulation
Authors: Wick Peter , Gansel Xavier , Oulevey Catherine , Page Valérie , Studer Ingrid , Dürst Michael , Sticher Liliane 
Published: May 2003

Abstract
The fusion of vesicles in the secretory pathway involves the interaction of t-soluble N-ethylmaleimide-sensitive factor attachment protein receptors (t-SNAREs) on the target membrane and v-SNAREs on the vesicle membrane. AtSNAP33 is an Arabidopsis homolog of the neuronal t-SNARE SNAP-25 involved in exocytosis and is localized at the cell plate and at the plasma membrane. In this paper, the expression of AtSNAP33 was analyzed after different biotic and abiotic stresses. The expression of AtSNAP33increased after inoculation with the pathogens Plectosporium tabacinum and virulent and avirulent forms ofPeronospora parasitica and Pseudomonas syringae pv tomato. The expression ofPR1 transcripts encoding the secreted pathogenesis-related protein 1 also increased after inoculation with these pathogens and the expression of AtSNAP33 preceded or occurred at the same time as the expression of PR1. AtSNAP33 was also expressed in npr1 plants that do not express PR1 after pathogen inoculation as well as incpr1 plants that overexpress PR1 in the absence of a pathogen. The level of AtSNAP33 decreased slightly in leaves inoculated with P. parasitica in theNahG plants, and eds5 andsid2 mutants that are unable to accumulate salicylic acid (SA) after pathogen inoculation, indicating a partial dependence on SA. AtSNAP33 was also expressed in systemic noninoculated leaves of plants inoculated with P. syringae. In contrast to the situation in infected leaves, the expression of AtSNAP33 in systemic leaves was fully SA dependent. Thus, the expression of AtSNAP33 after pathogen attack is regulated by SA-dependent and SA-independent pathways. Mechanical stimulation also led to an increase ofAtSNAP33 transcripts.
CACTA Transposons in Triticeae. A Diverse Family of High-Copy Repetitive Elements
Authors: Wicker Thomas , Guyot Romain , Yahiaoui Nabila , Keller Beat 
Published: May 2003

Abstract
In comparison with retrotransposons, which comprise the majority of the Triticeae genomes, very few class 2 transposons have been described in these genomes. Based on the recent discovery of a local accumulation of CACTA elements at theGlu-A3 loci in the two wheat species Triticum monococcum and Triticum durum, we performed a database search for additional such elements in Triticeae spp. A combination of BLAST search and dot-plot analysis of publicly available Triticeae sequences led to the identification of 41 CACTA elements. Only seven of them encode a protein similar to known transposases, whereas the other 34 are considered to be deletion derivatives. A detailed characterization of the identified elements allowed a further classification into seven subgroups. The major subgroup, designated the “Caspar ” family, was shown by hybridization to be present in at least 3,000 copies in theT. monococcum genome. The close association of numerous CACTA elements with genes and the identification of several similar elements in sorghum (Sorghum bicolor) and rice (Oryza sativa) led to the conclusion that CACTA elements contribute significantly to genome size and to organization and evolution of grass genomes.
STA11, a Chlamydomonas reinhardtii Locus Required for Normal Starch Granule Biogenesis, Encodes Disproportionating Enzyme. Further Evidence for a Function of α-1,4 Glucanotransferases during Starch Granule Biosynthesis in Green Algae
Authors: Wattebled Fabrice , Ral Jean-Philippe , Dauvillée David , Myers Alan M. , James Martha G. , Schlichting Ralf , Giersch Christoph , Ball Steven G. , D'Hulst Christophe 
Published: May 2003

Abstract
In Chlamydomonas reinhardtii, the presence of a defective STA11 locus results in significantly reduced granular starch deposition displaying major modifications in shape and structure. This defect simultaneously leads to the accumulation of linear malto-oligosaccharides (MOS). The mutants ofSTA11 were showed to lack d-enzyme, a plant α-1,4 glucanotransferase analogous to the Escherichia coli amylomaltase. We have cloned and characterized both the cDNA and gDNA corresponding to the C.reinhardtii d-enzyme. We now report allele-specific modifications of the d-enzyme gene in the mutants of STA11. These allele-specific modifications cosegregate with the corresponding sta11 mutations, thereby demonstrating that STA11 encodesd-enzyme. MOS production and starch accumulation were investigated during day and night cycles in wild-type and mutantC. reinhardtii cells. We demonstrate that in the algae MOS are produced during starch biosynthesis and degraded during the phases of net polysaccharide catabolism.
Expression of the Plastid-Located Glutamine Synthetase ofMedicago truncatula. Accumulation of the Precursor in Root Nodules Reveals an in Vivo Control at the Level of Protein Import into Plastids
Authors: Melo Paula M. , Lima Lı́gia M. , Santos Isabel M. , Carvalho Helena G. , Cullimore Julie V. 
Published: May 2003

Abstract
In this paper, we report the cloning and characterization of the plastid-located glutamine synthetase (GS) of Medicago truncatula Gaertn (MtGS2). A cDNA was isolated encoding a GS2 precursor polypeptide of 428 amino acids composing an N-terminal transit peptide of 49 amino acids. Expression analysis, by Westerns and by northern hybridization, revealed thatMtGS2 is expressed in both photosynthetic and non-photosynthetic organs. Both transcripts and proteins ofMtGS2 were detected in substantial amounts in root nodules, suggesting that the enzyme might be performing some important role in this organ. Surprisingly, about 40% of the plastid GS in nodules occurred in the non-processed precursor form (preGS2). This precursor was not detected in any other organ studied and moreover was not observed in non-fixing nodules. Cellular fractionation of nodule extracts revealed that preGS2 is associated with the plastids and that it is catalytically inactive. Immunogold electron microscopy revealed a frequent coincidence of GS with the plastid envelope. Taken together, these results suggest a nodule-specific accumulation of the GS2 precursor at the surface of the plastids in nitrogen-fixing nodules. These results may reflect a regulation of GS2 activity in relation to nitrogen fixation at the level of protein import into nodule plastids.
Salicylic Acid Alleviates the Cadmium Toxicity in Barley Seedlings
Authors: Metwally Ashraf , Finkemeier Iris , Georgi Manfred , Dietz Karl-Josef 
Published: May 2003

Abstract
Salicylic acid (SA) plays a key role in plant disease resistance and hypersensitive cell death but is also implicated in hardening responses to abiotic stressors. Cadmium (Cd) exposure increased the free SA contents of barley (Hordeum vulgare) roots by a factor of about 2. Cultivation of dry barley caryopses presoaked in SA-containing solution for only 6 h or single transient addition of SA at a 0.5 mmconcentration to the hydroponics solution partially protected the seedlings from Cd toxicity during the following growth period. Both SA treatments had little effect on growth in the absence of Cd, but increased root and shoot length and fresh and dry weight and inhibited lipid peroxidation in roots, as indicated by malondialdehyde contents, in the presence of Cd. To test whether this protection was due to up-regulation of antioxidant enzymes, activities and transcript levels of the H2O2-metabolizing enzymes such as catalase and ascorbate peroxidase were measured in control and SA-treated seedlings in the presence or absence of 25 μmCd. Cd stress increased the activity of these enzymes by variable extent. SA treatments strongly or completely suppressed the Cd-induced up-regulation of the antioxidant enzyme activities. Slices from leaves treated with SA for 24 h also showed an increased level of tolerance toward high Cd concentrations as indicated by chlorophyll a fluorescence parameters. The results support the conclusion that SA alleviates Cd toxicity not at the level of antioxidant defense but by affecting other mechanisms of Cd detoxification.
Mining for Single Nucleotide Polymorphisms and Insertions/Deletions in Maize Expressed Sequence Tag Data
Authors: Batley Jacqueline , Barker Gary , O'Sullivan Helen , Edwards Keith J. , Edwards David 
Published: May 2003

Abstract
We have developed a computer based method to identify candidate single nucleotide polymorphisms (SNPs) and small insertions/deletions from expressed sequence tag data. Using a redundancy-based approach, valid SNPs are distinguished from erroneous sequence by their representation multiple times in an alignment of sequence reads. A second measure of validity was also calculated based on the cosegregation of the SNP pattern between multiple SNP loci in an alignment. The utility of this method was demonstrated by applying it to 102,551 maize (Zea mays) expressed sequence tag sequences. A total of 14,832 candidate polymorphisms were identified with an SNP redundancy score of two or greater. Segregation of these SNPs with haplotype indicates that candidate SNPs with high redundancy and cosegregation confidence scores are likely to represent true SNPs. This was confirmed by validation of 264 candidate SNPs from 27 loci, with a range of redundancy and cosegregation scores, in four inbred maize lines. The SNP transition/transversion ratio and insertion/deletion size frequencies correspond to those observed by direct sequencing methods of SNP discovery and suggest that the majority of predicted SNPs and insertion/deletions identified using this approach represent true genetic variation in maize.
The Activity of the Chloroplastic Ndh Complex Is Regulated by Phosphorylation of the NDH-F Subunit
Authors: Lascano H. Ramiro , Casano Leonardo M. , Martı́n Mercedes , Sabater Bartolomé 
Published: May 2003

Abstract
Hydrogen peroxide (H2O2) induces increases, to different degrees, in transcripts, protein levels, and activity of the Ndh complex (EC 1.6.5.3). In the present work, we have compared the effects of relatively excess light, H2O2, dimethylthiourea (a scavenger of H2O2), and/or EGTA (a Ca2+chelator) on the activity and protein levels of the Ndh complex of barley (Hordeum vulgare cv Hassan) leaf segments. The results show the involvement of H2O2 in the modulation of both the protein level and activity of the Ndh complex and the participation of Ca2+ mainly in the activity regulation of pre-existing protein. Changes in Ndh complex activity could not be explained only by changes in Ndh protein levels, suggesting posttranslational modifications. Hence, we investigate the possible phosphorylation of the Ndh complex both in thylakoids and in the immunopurified Ndh complex using monoclonal phosphoamino acid antibodies. We demonstrate that the Ndh complex is phosphorylated in vivo at threonine residue(s) of the NDH-F polypeptide and that the level of phosphorylation is closely correlated with the Ndh complex activity. The emerging picture is that full activity of the Ndh complex is reached by phosphorylation of its NDH-F subunit in a H2O2- and Ca2+-mediated action.
Feedback in Hypothesis Testing: An ERP Study
Authors: Papo David , Baudonniére Pierre-Marie , Hugueville Laurent , Caverni Jean-Paul 
Published: May 2003

AbstractWe used event-related potentials (ERPs) to probe the effects of feedback in a hypothesis testing (HT) paradigm. Thirteen college students serially tested hypotheses concerning a hidden rule by judging its presence or absence in triplets of digits and revised them on the basis of an exogenous performance feedback. ERPs time-locked to performance feedback were then examined. The results showed differences between responses to positive and negative feedback at all cortical sites. Negative feedback, indicating incorrect performance, was associated to a negative deflection preceding a P300-like wave. Spatiotemporal principal component analysis (PCA) showed the interplay between early frontal components and later central and posterior ones. Lateralization of activity was selectively detectable at frontal sites, with a left frontal dominance for both positive and negative feedback. These results are discussed in terms of a proposed computational model of trial-to-trial feedback in HT in which the cognitive and emotive aspects of feedback are explicitly linked to putative mediating brain mechanisms. The properties of different feedback types and feedback-related deficits in depression are also discussed.
Facilitation of Implicit Motor Learning by Weak Transcranial Direct Current Stimulation of the Primary Motor Cortex in the Human
Authors: Nitsche Michael A. , Schauenburg Astrid , Lang Nicolas , Liebetanz David , Exner Cornelia , Paulus Walter , Tergau Frithjof 
Published: May 2003

Abstract
Transcranially applied weak direct currents are capable of modulating motor cortical excitability in the human. Anodal stimulation enhances excitability, cathodal stimulation diminishes it. Cortical excitability changes accompany motor learning. Here we show that weak direct currents are capable of improving implicit motor learning in the human. During performance of a serial reaction time task, the primary motor cortex, premotor, or prefrontal cortices were stimulated contralaterally to the performing hand. Anodal stimulation of the primary motor cortex resulted in increased performance, whereas stimulation of the remaining cortices had no effect. We conclude that the primary motor cortex is involved in the acquisition and early consolidation phase of implicit motor learning.
Heat shock protein 70 binds caspase-activated DNase and enhances its activity in TCR-stimulated T cells
Authors: Liu Qing-Li , Kishi Hiroyuki , Ohtsuka Kenzo , Muraguchi Atsushi 
Published: May 2003

AbstractDNA fragmentation is a hallmark of cells undergoing apoptosis and is mediated mainly by the caspase-activated DNase (CAD or DNA-fragmentation factor 40 [DFF40]), which is activated when released from its inhibitor protein (ICAD or DFF45) upon apoptosis signals. Here we analyzed the effect of heat shock protein 70 (Hsp70) on CAD activity in T-cell receptor (TCR)–induced apoptosis using a T-cell line (TAg-Jurkat). Overexpression of Hsp70 significantly augmented the apoptotic cell death as well as DNA fragmentation in CD3/CD28- or staurosporine-stimulated cells. Following stimulation of cells with CD3/CD28 or staurosporine, Hsp70 was coprecipitated with free CAD, but not with CAD associated with ICAD. Furthermore, the purified Hsp70 dose-dependently augmented DNA-fragmentation activity of caspase-3–activated CAD in a cell-free system. Peptide-binding domain–deleted Hsp70 could neither bind nor augment its activity, while adenosine triphosphate (ATP)–binding domain–deleted Hsp70 or the peptide-binding domain itself bound CAD and augmented its activity. These results indicate that the the binding of Hsp70 to the activated CAD via the peptide-binding domain augments its activity. Although CAD lost its activity in an hour after being released from ICAD in vitro, its activity was retained after an hour of incubation in the presence of Hsp70, suggesting that Hsp70 may be involved in stabilization of CAD activity. Finally, CAD that had been coprecipitated with Hsp70 from the cell lysate of staurosporine-activated 293T cells induced chromatin DNA fragmentation and its activity was not inhibited by ICAD. These results suggest that Hsp70 binds free CAD in TCR-stimulated T cells to stabilize and augment its activity.
An evaluation of neurobehavioural problems as perceived by family members and levels of family stress 1–3 years following traumatic brain injury in Japan
Authors: Watanabe Yuriko , Shiel Agnes , Asami Toyoko , Taki Kenji , Tabuchi Kazuo 
Published: May 2003

Objective: To ascertain the proportion of patients with traumatic brain injury (TBI) admitted to a Japanese district hospital and to evaluate the levels of stress and anxiety in families living with those TBI patients. Design: A retrospective study of patients admitted to hospital from April 1995 to March 1997 and a questionnaire study of family members of survivors. Setting and subjects: All patients referred or transferred to the Emergency Department at the Saga Medical School Hospital, Japan with a primary diagnosis of TBI were studied. Family members living with TBI patients were sent questionnaires. Main outcome measures: The Barthel Index, the Patient Competency Rating Scale, the modified Caregiver Strain Index and the Hospital Anxiety and Depression Scale. Results: There were 34 patients who required hospitalization for care relating to TBI. Of these, nine family members took part in the questionnaire study. Three carers reported fairly high levels of stress and another three carers were considered to be at risk of anxiety and depression. There was a tendency for family members who reported that patients had difficulties in performing behavioural tasks to have higher levels of stress themselves. Conclusion: These preliminary results showed that family members experienced certain levels of stress and were also at risk of anxiety and depression. The impact of TBI on families as well as patients should receive more attention.
Inter-rater reliability of the Barthel ADL Index: how does a researcher compare to a nurse?
Authors: Richards Suzanne H , Peters Tim J , Coast Joanna , Gunnell David J , Darlow Mary-Anne , Pounsford John 
Published: May 2003

Objectives: To investigate whether a nonclinical research assistant, using standardized scoring criteria, can reliably administer the Barthel Activities of Daily Living (ADL) Index in a sample of elderly inpatients. Design: Paired comparison of nurse and nonclinical research assistant Barthel Index assessments. Setting: Acute hospital wards from two hospitals in a UK Healthcare Trust, with a catchment population of approximately 224 000 people. Methods: A consecutive sample of 94 elderly patients with a variety of medical problems. Main outcome measures: Barthel ADL Index, Folstein Mini-Mental Status Examination. Results: Whilst the inter-rater reliability of the Barthel Index was within acceptable boundaries, two items out of ten had only fair agreement and low crude agreement (transfer and dressing) on Cohen's kappa scores. Conclusions: Depending on the differences observed in any particular context, the Barthel Index can be applied with reasonable reliability by nonclinical staff applying the standardized scoring criteria. It should be noted, however, that the kappa coefficients between clinical and nonclinical assessors tend to be lower than those found when comparing two clinically trained assessors in previous research.
The Frontal Lobe Score: part I: construction of a mental status of frontal systems
Authors: Ettlin Thierry M , Kischka Udo , Beckson Michael , Gaggiotti Manuela , Rauchfleisch Udo , Benson D Frank 
Published: May 2003

Objective: To develop a bedside mental status examination to assess the behavioural effects of damage to the frontal lobes. Design: A prospective clinical comparison of patients with cerebral lesions of different locations. Subjects: A total of 118 subjects were examined: 27 patients with cerebral lesions confined to the frontal lobes, 25 patients with cerebral lesions without involvement of the frontal lobes, 18 patients with mixed frontal/nonfrontal lesions, and 48 normal control subjects. Measures: Twenty-three mental status tests, clinical examinations and rating scales that had been reported as indicative of frontal lobe function were brought together. By statistical analysis, 12 tests and a neurobehavioural rating scale were selected. These constitute the Frontal Lobe Score (FLS). Results: The FLS detected pure frontal lesions with a sensitivity of 77.7%. It discriminated patients with frontal lesions from normal control subjects with a specificity of 100%. Differentiation from patients with nonfrontal lesions was obtained with a specificity of 84%. Conclusion: The Frontal Lobe Score is a useful screening instrument for the clinical detection of effects of frontal lobe damage.
Physical fitness training for wheelchair ambulation by the arm crank propulsion technique
Authors: Mukherjee Goutam , Bhowmik Partha , Samanta Amalendu 
Published: May 2003

Objective: To observe the effect of endurance training on novice users of an arm-propelled three-wheeled chair (APTWC), powered by asynchronous arm crank propulsion, in actual locomotive conditions. Study design: A continuous endurance training programme was administered by instructing subjects to propel themselves at free chosen speed (FCS) for 15 minutes, twice daily. Data were collected at two-week intervals consecutively and this was continued until the maximum beneficial effect was achieved. Setting: The study was conducted in outdoor settings similar to those the users encountered in their everyday life. Subjects: Twelve male paraplegics (below T10), age 30.5 ± 8.59 years, weight 41.75 kg (± 5.76) recommended to use the APTWC as an ambulatory device. Intervention: The propulsion speed (metres per minute), peak heart rate (beats per minute) and oxygen uptake (litres per minute) were measured in consecutive sessions at two-week intervals. Physiological cost index (beats m-1), oxygen consumption (ml kg-1 min-1) and oxygen cost (ml kg-1 m-1) were derived to assess fitness level. Results: Significant changes were observed in the variables following endurance training for 12 weeks. The propulsion speed increased considerably and the cardiorespiratory parameters were found to be reduced. One-way analysis of variance was done for each parameter separately for seven sets of readings taken to assess the overall change over the study period of 12 weeks. The F-ratios were found to be significant (p < 0.01) in each case, except for body weight and oxygen uptake. The pairwise comparison of the biweekly results of the parameters which showed an overall significant change over the study period revealed that after the first two weeks there was considerable change (p < 0.01) for all the parameters. The trend was upward for speed and downward for the other cardiovascular stress parameters. These trends continued until the 10th week showing significant change, after which the values become stable as was revealed by the statistical tests (p > 0.05). The percentage difference in the mean values from the initial stage (before training) to the 12th week ranged from 10.44% in the case of heart rate to 69.70% in the case of propulsion speed. Conclusion: Self-ambulation at free chosen speed regularly for 10–12 weeks provides efficiency and improves fitness status required for wheelchairs driven by an asynchronous arm crank propulsion technique and no special exercise programme is required.
Walking ability as a measure of treatment effect in early rheumatoid arthritis
Authors: Hamilton Jennifer , Brydson Gillian , Fraser Susan , Grant Margaret 
Published: May 2003

Objective: To assess the clinical usefulness of a prototype walkmat system in patients with early rheumatoid arthritis (RA). Subjects: Twenty-four subjects with early RA and symptomatic forefoot disease requiring therapy with second-line drugs were recruited. Design: Each subject underwent clinical assessment together with gait analysis on the contact sensitive walkmat system and Kistler forceplate before and after six months of treatment with second-line drugs. Two subjects were lost to follow-up. Results: There was the expected improvement in disease activity in response to therapy. Significant differences were also demonstrated in defined gait parameters that indicated improved weight-bearing and enhanced forefoot propulsion. Conclusion: Medical therapy improved walking ability in patients with RA and the walkmat system provided a useful adjunct to existing outcome measures in the assessment of lower limb function.