bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell Death in the Unicellular Chlorophyte Dunaliella tertiolecta. A Hypothesis on the Evolution of Apoptosis in Higher Plants and Metazoans
Authors: Segovia Marı́a , Haramaty Liti , Berges John A. , Falkowski Paul G. 
Published: May 2003

Abstract
Apoptosis is essential for normal growth and development of multicellular organisms, including metazoans and higher plants. Although cell death processes have been reported in unicellular organisms, key elements of apoptotic pathways have not been identified. Here, we show that when placed in darkness, the unicellular chlorophyte alga Dunaliella tertiolecta undergoes a form of cell death reminiscent of apoptosis in metazoans. Many morphological criteria of apoptotic cell death were met, including an increase in chromatin margination, degradation of the nucleus, and DNA fragmentation. Biochemical assays of the activities of cell death-associated proteases, caspases, measured using highly specific fluorogenic substrates, increased with time in darkness and paralleled the morphological changes. The caspase-like activities were inhibited by caspase-specific inhibitors. Antibodies raised against mammalian caspases cross-reacted with specific proteins in the alga. The pattern of expression of these immunologically reactive proteins was correlated with the onset of cell death. The occurrence of key components of apoptosis, and particularly a caspase-mediated cell death cascade in a relatively ancient linage of eukaryotic photoautotrophs, argues against current theories that cell death evolved in multicellular organisms. We hypothesize that key elements of cell death pathways were transferred to the nuclear genome of early eukaryotes through ancient viral infections in the Precambrian Ocean before the evolution of multicellular organisms and were subsequently appropriated in both metazoan and higher plant lineages.
Identification of Novel Mitochondrial Protein Components ofChlamydomonas reinhardtii. A Proteomic Approach
Authors: van Lis Robert , Atteia Ariane , Mendoza-Hernández Guillermo , González-Halphen Diego 
Published: May 2003

Abstract
Pure mitochondria of the photosynthetic algaChlamydomonas reinhardtii were analyzed using blue native-polyacrylamide gel electrophoresis (BN-PAGE). The major oxidative phosphorylation complexes were resolved: F1F0-ATP synthase, NADH-ubiquinone oxidoreductase, ubiquinol-cytochrome c reductase, and cytochrome c oxidase. The oligomeric states of these complexes were determined. The F1F0-ATP synthase runs exclusively as a dimer, in contrast to the C. reinhardtii chloroplast enzyme, which is present as a monomer and subcomplexes. The sequence of a 60-kD protein, associated with the mitochondrial ATP synthase and with no known counterpart in any other organism, is reported. This protein may be related to the strong dimeric character of the algal F1F0-ATP synthase. The oxidative phosphorylation complexes resolved by BN-PAGE were separated into their subunits by second dimension sodium dodecyl sulfate-PAGE. A number of polypeptides were identified mainly on the basis of their N-terminal sequence. Core I and II subunits of complex III were characterized, and their proteolytic activities were predicted. Also, the heterodimeric nature of COXIIA and COXIIB subunits in cytochrome c oxidase was demonstrated. Other mitochondrial proteins like the chaperone HSP60, the alternative oxidase, the aconitase, and the ADP/ATP carrier were identified. BN-PAGE was also used to approach the analysis of the major chloroplast protein complexes of C. reinhardtii.
Towards an Analysis of the Rice Mitochondrial Proteome
Authors: Heazlewood Joshua L. , Howell Katharine A. , Whelan James , Millar A. Harvey 
Published: May 2003

Abstract
Purified rice (Oryza sativa) mitochondrial proteins have been arrayed by isoelectric focusing/polyacrylamide gel electrophoresis (PAGE), by blue-native (BN) PAGE, and by reverse-phase high-performance liquid chromatography (LC) separation (LC-mass spectrometry [MS]). From these protein arrays, we have identified a range of rice mitochondrial proteins, including hydrophilic/hydrophobic proteins (grand average of hydropathicity = −1.27 to +0.84), highly basic and acid proteins (isoelectric point = 4.0–12.5), and proteins over a large molecular mass range (6.7–252 kD), using proteomic approaches. BN PAGE provided a detailed picture of electron transport chain protein complexes. A total of 232 protein spots from isoelectric focusing/PAGE and BN PAGE separations were excised, trypsin digested, and analyzed by tandem MS (MS/MS). Using this dataset, 149 of the protein spots (the products of 91 nonredundant genes) were identified by searching translated rice open reading frames from genomic sequence and six-frame translated rice expressed sequence tags. Sequence comparison allowed us to assign functions to a subset of 85 proteins, including many of the major function categories expected for this organelle. A further six spots were matched to rice sequences for which no specific function has yet been determined. Complete digestion of mitochondrial proteins with trypsin yielded a peptide mixture that was analyzed directly by reverse-phase LC via organic solvent elution from a C-18 column (LC-MS). These data yielded 170 MS/MS spectra that matched 72 sequence entries from open reading frame and expressed sequence tag databases. Forty-five of these were obtained using LC-MS alone, whereas 28 proteins were identified by both LC-MS and gel-based separations. In total, 136 nonredundant rice proteins were identified, including a new set of 23 proteins of unknown function located in plant mitochondria. We also report the first direct identification, to our knowledge, of PPR (pentatricopeptide repeat) proteins in the plant mitochondrial proteome. This dataset provides the first extensive picture, to our knowledge, of mitochondrial functions in a model monocot plant.
Quantitative Trait Loci and Comparative Genomics of Cereal Cell Wall Composition
Authors: Hazen Samuel P. , Hawley Robin M. , Davis Georgia L. , Henrissat Bernard , Walton Jonathan D. 
Published: May 2003

Abstract
Quantitative trait loci (QTLs) affecting sugar composition of the cell walls of maize (Zea mays) pericarp were mapped as an approach to the identification of genes involved in cereal wall biosynthesis. Mapping was performed using the IBM (B73 × Mo17) recombinant inbred line population. There were statistically significant differences between B73 and Mo17 in content of xylose (Xyl), arabinose (Ara), galactose (Gal), and glucose. Thirteen QTLs were found, affecting the content of Xyl (two QTLs), Ara (two QTLs), Gal (five QTLs), Glc (two QTLs), Ara + Gal (one QTL), and Xyl + Glc (one QTL). The chromosomal regions corresponding to two of these, affecting Ara + Gal and Ara on maize chromosome 3, could be aligned with a syntenic region on rice (Oryza sativa) chromosome 1, which has been completely sequenced and annotated. The contiguous P1-derived artificial chromosome rice clones covering the QTLs were predicted to encode 117 and 125 proteins, respectively. Two of these genes encode putative glycosyltransferases, displaying similarity to carbohydrate-active enzyme database family GT4 (galactosyltransferases) or to family GT64 (C-terminal domain of animal heparan synthases). The results illustrate the potential of using natural variation, emerging genomic resources, and homeology within the Poaceae to identify candidate genes involved in the essential process of cell wall biosynthesis.
The Cotton Kinesin-Like Calmodulin-Binding Protein Associates with Cortical Microtubules in Cotton Fibers
Authors: Preuss Mary L. , Delmer Deborah P. , Liu Bo 
Published: May 2003

Abstract
Microtubules in interphase plant cells form a cortical array, which is critical for plant cell morphogenesis. Genetic studies imply that the minus end-directed microtubule motor kinesin-like calmodulin-binding protein (KCBP) plays a role in trichome morphogenesis in Arabidopsis. However, it was not clear whether this motor interacted with interphase microtubules. In cotton (Gossypium hirsutum) fibers, cortical microtubules undergo dramatic reorganization during fiber development. In this study, cDNA clones of the cotton KCBP homolog GhKCBP were isolated from a cotton fiber-specific cDNA library. During cotton fiber development from 10 to 21 DPA, the GhKCBP protein level gradually decreases. By immunofluorescence, GhKCBP was detected as puncta along cortical microtubules in fiber cells of different developmental stages. Thus our results provide evidence that GhKCBP plays a role in interphase cell growth likely by interacting with cortical microtubules. In contrast to fibers, in dividing cells of cotton, GhKCBP localized to the nucleus, the microtubule preprophase band, mitotic spindle, and the phragmoplast. Therefore KCBP likely exerts multiple roles in cell division and cell growth in flowering plants.
Representation of Change: Separate Electrophysiological Markers of Attention, Awareness, and Implicit Processing
Authors: Fernandez-Duque Diego , Grossi Giordana , Thornton Ian M. , Neville Helen J. 
Published: May 2003

Abstract
Awareness of change within a visual scene only occurs in the presence of focused attention. When two versions of a complex scene are presented in alternating sequence separated by a blank mask, unattended changes usually remain undetected, although they may be represented implicitly. To test whether awareness of change and focused attention had the same or separable neurophysiological substrates, and to search for the neural substrates of implicit representation of change, we recorded event-related brain potentials (ERPs) during a change blindness task. Relative to active search, focusing attention in the absence of a change enhanced an ERP component over frontal sites around 100–300 msec after stimulus onset, and in posterior sites at the 150–300 msec window. Focusing attention to the location of a change that subjects were aware of replicated those attentional effects, but also produced a unique positive deflection in the 350–600 msec window, broadly distributed with its epicenter in mediocentral areas. The unique topography and time course of this latter modulation, together with its dependence on the aware perception of change, distinguishes this “awareness of change” electrophysiological response from the electrophysiological effects of focused attention. Finally, implicit representation of change elicited a distinct electrophysiological event: Unaware changes triggered a positive deflection at the 240–300 msec window, relative to trials with no change. Overall, the present data suggest that attention, awareness of change, and implicit representation of change may be mediated by separate underlying systems.
Temporal Modulation of Spatial Tactile Extinction in Right-Brain-Damaged Patients
Authors: Guerrini Chiara , Berlucchi Giovanni , Bricolo Emanuela , Aglioti Salvatore M. 
Published: May 2003

Abstract
Unilateral and bilateral electrotactile stimuli were delivered to both hands of 11 right-brain-damaged (RBD) patients with left tactile extinction and 20 healthy subjects. Bimanual stimuli could be presented simultaneously or with varying stimulus onset asynchronies (SOAs). Subjects indicated their detection of unilateral or bilateral stimuli, their judgements of whether stimuli were simultaneous or successive, and, in the latter case, which side came first. In RBD patients, extinction was maximal with simultaneous presentations and decreased as SOA increased. With short SOAs, omissions of left-sided stimuli occurred with both right-side and left-side stimulus precedence, suggesting a forward and backward interference of the right stimulus on the processing of the left stimulus within a time window of at least 100 msec. In contrast, there was no interference of the left stimulus on the detection of the right stimulus. Unlike controls, extinction patients rarely expressed simultaneity judgements, but those that were produced tended to be veridical or nearly so, like in normal controls. Whereas controls expressed generally accurate judgements of right or left precedence, patients showed a bias toward a right precedence and a maximal uncertainty between left-first and right-first choices when the left stimulus had a lead between 100 and 200 msec. The results are consistent with the hypothesis that, as in other sensory modalities, tactile extinction is associated with an abnormal persistent bias of attention toward the ipsilesional side that delays the processing of contralesional stimuli. However, the finding that both extinction and explicit judgements of simultaneity tended to occur with simultaneous bilateral stimuli suggest the presence of some residual neural capacity to detect precise temporal coincidence.
Platelet α2β1 integrin activation: contribution of ligand internalization and the α2-cytoplasmic domain
Authors: Wang Zhengyan , Leisner Tina M. , Parise Leslie V. 
Published: May 2003

AbstractThe α2β1 integrin is a major collagen receptor on platelets. Although it has been proposed that α2β1, like αIIbβ3, undergoes agonist-induced activation, neither the potential contributions of α2β1 receptor/ligand internalization to the increase in ligand binding nor the roles of the α2 and β1 cytoplasmic domains in activation of this integrin have been previously explored. Activation of α2β1 was assessed with fluorescein isothiocyanate–labeled soluble type I collagen binding to platelets by flow cytometry. Although collagen internalization in response to agonist activation of platelets was significant, agonist-induced collagen binding still occurred under conditions that block internalization, with minimal changes in cell surface α2β1 expression. Introduction of cell-permeable peptides containing the α2 cytoplasmic tail, and especially the membrane proximal KLGFFKR domain, induced α2β1 activation in resting platelets, whereas a cell-permeable peptide containing the β1 cytoplasmic tail was without effect. Thus, collagen binding to stimulated platelets is increased due to α2β1 activation, in addition to internalization, and the GFFKR motif appears to play an important role in the activation process.
Prior gemtuzumab ozogamicin exposure significantly increases the risk of veno-occlusive disease in patients who undergo myeloablative allogeneic stem cell transplantation
Authors: Wadleigh Martha , Richardson Paul G. , Zahrieh David , Lee Stephanie J. , Cutler Corey , Ho Vincent , Alyea Edwin P. , Antin Joseph H. , Stone Richard M. , Soiffer Robert J. , DeAngelo Daniel J. 
Published: May 2003

AbstractGemtuzumab ozogamicin (GO), a monoclonal antibody used in the treatment of acute myelogenous leukemia (AML) has been linked to the development of venoocclusive disease (VOD). We conducted a retrospective study of 62 patients with previously treated AML/MDS (myelodysplastic syndrome) who underwent allogeneic stem cell (SC) transplantation at our institution from December 2000 to October 2002 to determine whether GO exposure prior to allogeneic SC transplantation increases the risk of developing VOD. Fourteen patients received GO prior to SC transplantation. Of 62 patients, 13 (21%) developed VOD; 9 (64%) of 14 with prior GO exposure developed VOD compared with 4 (8%) of 48 without prior GO exposure (P &lt; .0001). Logistic regression controlling for sex, disease status, donor type, and graft-versus-host disease prophylaxis identified prior treatment with GO as a significant risk factor for VOD (odds ratio [OR], 21.6; 95% confidence interval [CI], 4.2-112.2]. Nine of 10 patients who underwent SC transplantation 3.5 months or less following GO developed VOD compared with none of 4 patients who underwent SC transplantation more than 3.5 months from GO administration. Three of 14 patients who received GO prior to SC transplantation died of VOD. We conclude that patients undergoing SC transplantation within a short interval from GO administration are at increased risk of developing VOD.
Granule stores from cellubrevin/VAMP-3 null mouse platelets exhibit normal stimulus-induced release
Authors: Schraw Todd D. , Rutledge Tara W. , Crawford Garland L. , Bernstein Audrey M. , Kalen Amanda L. , Pessin Jeffery E. , Whiteheart Sidney W. 
Published: May 2003

AbstractIt is widely accepted that the platelet release reaction is mediated by heterotrimeric complexes of integral membrane proteins known as SNAREs (SNAP receptors). In an effort to define the precise molecular machinery required for platelet exocytosis, we have analyzed platelets from cellubrevin/VAMP-3 knockout mice. Cellubrevin/VAMP-3 has been proposed to be a critical v-SNARE for human platelet exocytosis; however, data reported here suggest that it is not required for platelet function. Upon stimulation with increasing concentrations of thrombin, collagen, or with thrombin for increasing time there were no differences in secretion of [3H]-5HT (dense core granules), platelet factor IV (alpha granules), or hexosaminidase (lysosomes) between null and wild-type platelets. There were no gross differences in bleeding times nor in agonist-induced aggregation measured in platelet-rich plasma or with washed platelets. Western blotting of wild-type, heterozygous, and null platelets confirmed the lack of cellubrevin/VAMP-3 in nulls and showed that most elements of the secretion machinery are expressed at similar levels. While the secretory machinery in mice was similar to humans, mice did express apparently higher levels of synaptobrevin/VAMP-2. These data show that the v-SNARE, cellubrevin/VAMP-3 is not a requirement for the platelet release reaction in mice.
The role of affect on the perception of disability in multiple sclerosis
Authors: Smith S J , Young C A 
Published: May 2003

Objective: To determine the prevalence of depression in multiple sclerosis in the community and to assess how the presence of depression affects patients' perception of their disability. Design: Consecutive case series. Setting: The study was carried out at a regional multiple sclerosis (MS) clinic. Subjects: Eighty-eight patients with MS. Main outcome measures: Patients were asked to complete the following questionnaires: Hospital Anxiety and Depression Scale (HADS), Beck Depression Inventory (BDI), Rankin Scale of Disability/Handicap (completed by patient and physician to assess relative perceived disability) and two visual analogue scales (coping ability and perceived service adequacy). Results: Thirty-nine per cent were case level for depression using the BDI criteria of Sullivan; 17% were case level for depression (34% borderline case) and 34% case level for anxiety on HADS. Depressed patients using both BDI and HADS criteria were three times more likely than nondepressed patients to perceive their disability as being greater than the physicians' perception ( p < 0.001). Conclusion: Depression is common in MS and adversely affects patients' perception of their disability.
The COSTAR wheelchair study: a two-centre pilot study of self-propulsion in a wheelchair in early stroke rehabilitation
Authors: Barrett J A , Watkins C , Plant R , Dickinson H , Clayton L , Sharma A K , Reston A , Gratton J , Fall S , Flynn A , Smith T , Leathley M , Smith S , Barer D H 
Published: May 2003

Objective: It is uncertain whether self-propulsion in a wheelchair should be encouraged or discouraged in the early stages of stroke rehabilitation. Design: A two-centre pilot study to assess the feasibility of performing a multicentre randomized controlled trial on this subject. Setting: Clatterbridge and Aintree Stroke Rehabilitation Units, Merseyside, UK. Subjects: Forty early stroke patients (mean age 67 years) in whom it was uncertain whether self-propulsion in a wheelchair should be encouraged were studied. Intervention: A central randomization service at Newcastle University was used to determine the policy about wheelchair provision and use for each patient. They were allocated to either an ‘encouraged to self-propel’ or a ‘discouraged from self-propulsion group’. Outcome measures used: Independent outcome assessment was performed by postal questionnaire and telephone interview using the Barthel ADL Scale, Nottingham Extended ADL Scales and the shortened General Health Questionnaire (GHQ-12) at 3 and 12 months. Patient's length of stay and their Ashworth tone score were also measured either at three months or when they were discharged from hospital. Results: After considerable preparation time it was possible to conduct a trial on self-propulsion in early stroke rehabilitation in the two-pilot centres. No major differences were found between the pilot groups for any of the outcome measures. Conclusions: A multicentre randomized controlled trial to assess this question is feasible but further work is being conducted before proceeding, to satisfy the concerns expressed to our group regarding the appropriateness of the intervention and the outcome measures. Address for correspondence: JA Barrett, Clatterbridge Hospital, Wirral, Merseyside CH69 4JY, UK. e-mail: jabarrett@clatterbridgesru.freeserve.co.uk
An exploration of the effects of weighted garments on balance and gait of stroke patients with residual disability
Authors: Pomeroy V M , Evans B , Falconer M , Jones D , Hill E , Giakas G 
Published: May 2003

Objective: To explore the effects of weighted garments on the balance and gait of stroke patients. Design: A pilot randomized controlled study with blinded measurement. Setting: Weighted garments were worn by patients living in the community and measurement was made in a hospital-based gait laboratory. Subjects: Twenty-four adults who were at least six months post stroke and were able to walk 10 metres with or without assistance or a walking aid. Intervention: The six-week treatment-phase subjects were given a set of weighted garments which they were shown how to apply and instructed to wear on their paretic side. Subjects randomly allocated to the six-week control phase were not given any weighted garments. Main outcome measures: Balance was measured with the Berg Balance Scale. Gait was measured using GaitMat II, an instrumented walkway. Gait parameters of interest were velocity and symmetry of: step length; single support time; double support time; and support base width. Measures were made at baseline before randomization (baseline) and at the end of the six weeks of intervention (outcome). Results: No statistically significant differences were found between the treatment and control groups at outcome for balance (Mann–Whitney U-test; p = 0.74), gait velocity (p = 0.68) or symmetry of gait parameters (p = 0.33 to p = 0.75). Conclusions: We found no evidence to support the clinical use of these weighted garments for stroke survivors.