bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gts1p stabilizes oscillations in energy metabolism by activating the transcription of TPS1 encoding trehalose-6-phosphate synthase 1 in the yeast Saccharomyces cerevisiae
Authors: XU Zhaojun , YAGUCHI So-ichi , TSURUGI Kunio 
Published: September 2004

We reported previously that Gts1p regulates oscillations of heat resistance in concert with those of energy metabolism in continuous cultures of the yeast Saccharomyces cerevisiae by inducing fluctuations in the levels of trehalose, but not in those of Hsp104 (heat shock protein 104). Further, the expression of TPS1, encoding trehalose-6-phosphate synthase 1, and HSP104 was activated by Gts1p in combination with Snf1 kinase, a transcriptional activator of glucose-repressible genes, in batch cultures under derepressed conditions. Here we show that, in continuous cultures, the mRNA level of TPS1 increased 6-fold in the early respiro–fermentative phase, while that of HSP104 did not change. The expression of SUC2, a representative glucose-repressible gene encoding invertase, also fluctuated, suggesting the involvement of the Snf1 kinase in the periodic activation of these genes. However, this possibility was proven to be unlikely, since the oscillations in both TPS1 and SUC2 mRNA expression were reduced by approx. 3-fold during the transient oscillation in gts1Δ (GTS1-deleted) cells, in which the energy state determined by extracellular glucose and intracellular adenine nucleotide levels was comparable with that in wild-type cells. Furthermore, neither the mRNA level nor the phosphorylation status of Snf1p changed significantly during the oscillation. Thus we suggest that Gts1p plays a major role in the oscillatory expression of TPS1 and SUC2 in continuous cultures of Saccharomyces cerevisiae, and hypothesized that Gts1p stabilizes oscillations in energy metabolism by activating trehalose synthesis to facilitate glycolysis at the shift from the respiratory to the respiro–fermentative phase.
Plasma from women with severe pre-eclampsia increases microvascular permeability in an animal model in vivo
Authors: NEAL Christopher R. , HUNTER Alyson J. , HARPER Steven J. , SOOTHILL Peter W. , BATES David O. 
Published: September 2004

Pre-eclampsia results in oedema, hypertension and proteinuria, and is associated with increased vascular permeability. A number of studies have pointed to the existence of a circulating macromolecule that induces this endothelial dysfunction. To test whether this circulating factor could increase vascular permeability, we have measured the effect of dialysed human plasma from pregnant women with mild or severe pre-eclampsia (pre-eclamptic toxaemia). Plasma was collected from patients with mild or severe pre-eclampsia and from normotensive women. Plasma was dialysed against frog Ringer's solution using a 12–14 kDa molecular-mass cut-off dialysis tubing. πc (colloid osmotic pressure) was measured with a modified Hansen oncometer. Lp (hydraulic conductivity) and σ (oncotic reflection coefficient) were measured in individually perfused frog mesenteric microvessels using the Landis–Michel technique during perfusion with dialysed plasma. Perfusion of vessels with normal plasma or plasma from patients with mild pre-eclampsia did not alter either Lp or σ. However, plasma from patients with severe pre-eclampsia resulted in a 3.8±0.3-fold increase in Lp and a reduction in σ from 0.96±0.03 to 0.80±0.11. There was a significant correlation between the change in σ and the change in Lp, suggesting that the increase in permeability was due to an increase in pore size in these vessels. A circulating macromolecule in human plasma in severe pre-eclampsia is therefore able to increase vascular permeability in an animal model. The nature of the circulating macromolecule is not known, except that it is, or is bound to, a molecule greater than 12 kDa.
wEMBOSS: a web interface for EMBOSS
Authors: Sarachu Martín , Colet Marc 
Published: September 2004

Abstract
Summary: wEMBOSS provides a web environment from which the user can access EMBOSS in a user-friendly way. wEMBOSS supplies each user with space and tools to organize and review his or her work.
Availability: wEMBOSS can be downloaded at http://www.wemboss.org
Contact: msarachu@biol.unlp.edu.ar
GLAD: a system for developing and deploying large-scale bioinformatics grid
Authors: Teo Yong-Meng , Wang Xianbing , Ng Yew-Kwong 
Published: September 2004

AbstractMotivation: Grid computing is used to solve large-scale bioinformatics problems with gigabytes database by distributing the computation across multiple platforms. Untill now in developing bioinformatics grid applications, it is extremely tedious to design and implement the component algorithms and parallelization techniques for different classes of problems, and to access remotely located sequence database files of varying formats across the grid. In this study, we propose a grid programming toolkit, GLAD (Grid Life sciences Applications Developer), which facilitates the development and deployment of bioinformatics applications on a grid.Results: GLAD has been developed using ALiCE (Adaptive scaLable Internet-based Computing Engine), a Java-based grid middleware, which exploits the task-based parallelism. Two bioinformatics benchmark applications, such as distributed sequence comparison and distributed progressive multiple sequence alignment, have been developed using GLAD.Availability: GLAD and ALiCE are available at http://www.comp.nus.edu.sg/~teoym/alice.htmContact: teoym@comp.nus.edu.sg
Formation of an SCFZTL complex is required for proper regulation of circadian timing
Authors: Han Linqu , Mason Mary , Risseeuw Eddy P. , Crosby William L. , Somers David E. 
Published: September 2004

SummaryThe circadian timing system involves an autoregulatory transcription/translation feedback loop that incorporates a diverse array of factors to maintain a 24‐h periodicity. In Arabidopsis a novel F‐box protein, ZEITLUPE (ZTL), plays an important role in the control of the free‐running period of the circadian clock. As a class, F‐box proteins are well‐established components of the Skp/Cullin/F‐box (SCF) class of E3 ubiquitin ligases that link the target substrates to the core ubiquitinating activity of the ligase complex via direct association with the Skp protein. Here we identify and characterize the SCFZTL complex in detail. Yeast two‐hybrid tests demonstrate the sufficiency and necessity of the F‐box domain for Arabidopsis Skp‐like protein (ASK) interactions and the dispensability of the unique N‐terminal LOV domain in this association. Co‐immunoprecipitation of full‐length (FL) ZTL with the three known core components of SCF complexes (ASK1, AtCUL1 and AtRBX1) demonstrates that ZTL can assemble into an SCF complex in vivo. F‐box‐containing truncated versions of ZTL (LOV‐F and F‐kelch) can complex with SCF components in vivo, whereas stably expressed LOV or kelch domains alone cannot. Stable expression of F‐box‐mutated FL ZTL eliminates the shortened period caused by mild ZTL overexpression and also abolishes ASK1 interaction in vivo. Reduced levels of the core SCF component AtRBX1 phenocopy the long period phenotype of ztl loss‐of‐function mutations, demonstrating the functional significance of the SCFZTL complex. Taken together, our data establish SCFZTL as an essential SCF class E3 ligase controlling circadian period in plants.
Agrodrench: a novel and effective agroinoculation method for virus‐induced gene silencing in roots and diverse Solanaceous species
Authors: Ryu Choong‐Min , Anand Ajith , Kang Li , Mysore Kirankumar S. 
Published: September 2004

SummaryVirus‐induced gene silencing (VIGS) is an extremely powerful tool for plant functional genomics. We usedTobacco rattle virus(TRV)‐derived VIGS vectors expressed from binary vectors withinAgrobacteriumto induce RNA silencing in plants. Leaf infiltration is the most common method of agroinoculation used for VIGS but this method has limitations as it is laborious for large‐scale screening and some plants are difficult to infiltrate. Here we have developed a novel and simple method of agroinoculation, called ‘agrodrench’, where soil adjacent to the plant root is drenched with anAgrobacteriumsuspension carrying the TRV‐derived VIGS vectors. By agrodrench we successfully silenced the expression of phytoene desaturase (PDS), a 20S proteasome subunit (PB7) or Mg‐protoporphyrin chelatase (Chl H) encoding genes inNicotiana benthamianaand in economically important crops such as tomato, pepper, tobacco, potato, and Petunia, all belonging to the Solanaceae family. An important aspect of agrodrench is that it can be used for VIGS in very young seedlings, something not possible by the leaf infiltration method, which usually requires multiple fully expanded leaves for infiltration. We also demonstrated that VIGS functioned to silence target genes in plant roots. The agrodrench method of agroinoculation was more efficient than the leaf infiltration method for VIGS in roots. Agrodrench will facilitate rapid large‐scale functional analysis of cDNA libraries and can also be applied to plants that are not currently amenable to VIGS technology by conventional inoculation methods.
Functional recovery and axonal growth following spinal cord transection is accelerated by sustained l‐DOPA administration
Authors: Doyle L. M. F. , Roberts B. L. 
Published: September 2004

AbstractThe eel, Anguilla anguilla, as with other fish species, recovers well from spinal cord injury. We assessed the quality of locomotion of spinally transected eels from measurements made from video recordings of individuals swimming at different speeds in a water tunnel. Following transection of the spinal cord just caudal to the anus, the animals displayed higher tail beat frequencies and lower tail beat amplitudes than before surgery, owing to the loss of power in this region. Swimming performance then progressively recovered, appearing normal within 1 month of surgery. Eels with similar transections, but given regular, repeated intraperitoneal injections (50 mg/kg) of l‐3,4‐dihydroxyphenylalanine (l‐DOPA) showed an equivalent pattern of decline and recovery that was 10–20 days shorter than that seen in non‐treated fish. Axonal growth into the denervated cord, as determined from anterograde labelling experiments, was also more rapid in the drug‐treated fish. l‐DOPA treatment increased the activity of all fish for up to 18 h, and accelerated the spontaneous movements (‘spinal swimming’) made by the denervated, caudal portion of the animal that appeared following transection. We suggest that this enhancement of locomotion underlies the accelerated axonal growth and, hence, functional recovery.
Thyroid hormone participates in the regulation of neural stem cells and oligodendrocyte precursor cells in the central nervous system of adult rat
Authors: M. Fernandez , S. Pirondi , M. Manservigi , L. Giardino , L. Calzà 
Published: September 2004

AbstractOligodendrocyte development and myelination are under thyroid hormone control. In this study we analysed the effects of chronic manipulation of thyroid status on the expression of a wide spectrum of oligodendrocyte precursor cells (OPCs) markers and myelin basic protein (MBP) in the subventricular zone (SVZ), olfactory bulb and optic nerve, and on neural stem cell (NSC) lineage in adult rats. Hypo‐ and hyperthyroidism were induced in male rats, by propyl‐thio‐uracil (PTU) and l‐thyroxin (T4) treatment, respectively. Hypothyroidism increased and hyperthyroidism downregulated proliferation in the SVZ and olfactory bulb (Ki67 immunohistochemistry and Western blotting, bromodeoxyuridine uptake). Platelet‐derived growth factor receptor alpha (PDGFα‐R) and MBP mRNA levels decreased in the optic nerve of hypothyroid rats; the same also occurred at the level of MBP protein. Hyperthyroidism slightly upregulates selected markers such as NG2 in the olfactory bulb. The lineage of cells derived from primary cultures of NSC prepared from the forebrain of adult hypo‐ and hyperthyroid also differs from those derived from control animals. Although no difference of in vitro proliferation of NSCs was observed in the presence of epidermal growth factor, maturation of oligodendrocytes (defined by process number and length) was enhanced in hyperthyroidism, suggesting a more mature state than in control animals. This difference was even greater when compared with the hypothyroid group, the morphology of which suggested a delay in differentiation. These results indicate that thyroid hormone affects NSC and OPC proliferation and maturation also in adulthood.
Transcranial magnetic stimulation of the human motor cortex influences the neuronal activity of subthalamic nucleus
Authors: Strafella Antonio P. , Vanderwerf Ysbrand , Sadikot Abbas F. 
Published: September 2004

AbstractThe critical role of the subthalamic nucleus (STN) in the control of movement and parkinsonian symptoms is well established. Research in animals suggests that the cerebral cortex plays an important role in regulating the activity of the STN but this control is not known in humans. The most extensive cortical innervation of the STN originates from motor areas. Here, we used transcranial magnetic stimulation (TMS) during intraoperative single‐unit recordings from STN, in six patients with Parkinson's disease (PD) undergoing implantation of deep brain stimulators, to determine whether TMS of the motor cortex (MC) modulates the activity of STN and to investigate in vivo the functional organization of the corticosubthalamic circuit in the human brain. Single‐pulse TMS of the MC induced an excitation in 74.9% of neurons investigated. This activation was followed by a long‐lasting inhibition of the STN neuronal activity that did not correlate with PD severity. Responsive neurons to TMS of the hand area of motor cortex were located mainly in the lateral and dorsal region of the subthalamus while unresponsive cells had a prevalently medial distribution. This is the first report of TMS‐induced modulation of STN neuronal activity in humans. These findings open up new avenues for in vivo studies of corticosubthalamic interactions in human brain and PD.
Bimodal speech: early suppressive visual effects in human auditory cortex
Authors: Besle Julien , Fort Alexandra , Delpuech Claude , Giard Marie‐Hélène 
Published: September 2004

AbstractWhile everyone has experienced that seeing lip movements may improve speech perception, little is known about the neural mechanisms by which audiovisual speech information is combined. Event‐related potentials (ERPs) were recorded while subjects performed an auditory recognition task among four different natural syllables randomly presented in the auditory (A), visual (V) or congruent bimodal (AV) condition. We found that: (i) bimodal syllables were identified more rapidly than auditory alone stimuli; (ii) this behavioural facilitation was associated with cross‐modal [AV − (A + V)] ERP effects around 120–190 ms latency, expressed mainly as a decrease of unimodal N1 generator activities in the auditory cortex. This finding provides evidence for suppressive, speech‐specific audiovisual integration mechanisms, which are likely to be related to the dominance of the auditory modality for speech perception. Furthermore, the latency of the effect indicates that integration operates at pre‐representational stages of stimulus analysis, probably via feedback projections from visual and/or polymodal areas.
Nitric oxide increases the spontaneous firing rate of rat medial vestibular nucleus neurons in vitro via a cyclic GMP‐mediated PKG‐independent mechanism
Authors: Podda Maria Vittoria , Marcocci Maria Elena , Oggiano Leonardo , D'Ascenzo Marcello , Tolu Eusebio , Palamara Anna Teresa , Azzena Gian Battista , Grassi Claudio 
Published: September 2004

AbstractThe effects of nitric oxide (NO) on the discharge rate of medial vestibular nucleus neurons (MVNn) were investigated in rat brainstem slices. The NO‐donor sodium nitroprusside (SNP, 200 µm) caused a marked enhancement (+36.7%) of MVNn spontaneous firing rate, which was prevented by the NO‐scavenger, carboxy‐PTIO (300 µm). The SNP effects were not modified (+37.4%) by synaptic uncoupling, suggesting that NO influences intrinsic membrane properties of MVNn rather than the synaptic input they receive. The excitatory action of SNP was virtually abolished by slice pretreatment with the soluble guanylyl cyclase inhibitor, ODQ (10 µm), and it was mimicked (+33.1%) by the cGMP analogue 8‐Br‐cGMP (400 µm). Protein kinase G (PKG) and cAMP/protein kinase A (PKA) were both excluded as downstream effectors of the NO/cGMP‐induced excitation. However, the cyclic nucleotide‐gated (CNG) channel blockers, l‐cis‐diltiazem (LCD, 100 µm) and Sp‐8‐Br‐PET‐cGMPS (100 µm), significantly reduced the firing rate increase produced by 8‐Br‐cGMP. Moreover, LCD alone decreased spontaneous MVNn firing (−19.7%), suggesting that putative CNG channels may contribute to the tonic control of resting MVNn discharge. 8‐Br‐cAMP (1 mm) also elicited excitatory effects in MVNn (+40.8%), which occluded those induced by 8‐Br‐cGMP, indicating that the two nucleotides share a common target. Finally, nested‐polymerase chain reaction assay revealed the expression of CNG channel α subunit transcript in MVNn. Our data provide the first demonstration that NO/cGMP signalling modulates MVNn spontaneous firing through a mechanism that is independent of PKG or PKA and probably involves activation of CNG channels.
In vivo contribution of h‐channels in the septal pacemaker to theta rhythm generation
Authors: Kocsis Bernat , Li Shaomin 
Published: September 2004

AbstractOne of the most intriguing network‐level inferences made on the basis of in vitro and modelling data regarding the role of Ih current was that they participate in rhythmogenesis in different parts of the brain. The nature of Ih contribution to various neuronal oscillations is far from uniform however, and the proper evaluation of the role of Ih in each particular structure requires in situ investigations in the intact brain. In this study we tested the effect of Ih blockade in the medial septum on hippocampal theta rhythm in anaesthetized and freely behaving rats. We could not confirm the recent report of elimination of theta by septal injection of ZD7288 [C. Xu et al. (2004) Eur. J. Neurosci., 19, 2299–2309]; the observed effects were more subtle and more specific. We found that Ih blockade in the medial septum substantially decreased the frequency of hippocampal oscillations without changing the context in which theta occurred, i.e. specific behaviours in freely moving rats and spontaneous switching and brainstem stimulation under anaesthesia. Septal injection of ZD7288 eliminated atropine‐resistant theta elicited by high intensity electrical stimulation of the reticular formation in anaesthetized rats but was ineffective in combination with the muscarinic agonist, carbachol. Thus, functional Ih was necessary for the septum to generate or transmit high frequency theta rhythm elicited by strong ascending activation, whereas low frequency theta persisted after Ih blockade. These results suggest that Ih plays a specific role in septal theta generation by promoting fast oscillations during exploratory behaviour and rapid eye movement sleep.
Atypical Working Hours: Consequences for Childcare Arrangements
Authors: Bihan Blanche Le , Martin Claude 
Published: September 2004

Abstract This paper analyses the care arrangements of those dual‐earner couples and lone‐parent families who are under strong pressure because of atypical and unpredictable working hours. In these situations, the parents have to invent day‐to‐day, week‐to‐week solutions for the care needs of their children, mobilizing all available formal and informal resources. The objective is to understand the different ways in which families manage such atypical working hours in three different countries (Finland, France and Portugal). What are the main strategies of the parents in facing this pressure? Do these include negotiations between the parents on the division of tasks, mobilization of ex‐partners, grandparents, brothers and sisters, neighbours, and the different solutions offered by the formal resources? In the first part of the paper, we present the challenges and consequences of atypical working hours for families and institutions in Europe, in particular in Finland, France and Portugal. We then analyse some of the childcare arrangements as well as the impact of the provision of childcare services.
Rating Teams and Analysing Outcomes in One-Day and Test Cricket
Authors: Allsopp P. E. , Clarke Stephen R. 
Published: September 2004

SummaryMultiple linear regression techniques are applied to determine the relative batting and bowling strengths and a common home advantage for teams playing both innings of international one-day cricket and the first innings of a test-match. It is established that in both forms of the game Australia and South Africa were rated substantially above the other teams. It is also shown that home teams generally enjoyed a significant advantage. Using the relative batting and bowling strengths of teams, together with parameters that are associated with common home advantage, winning the toss and the establishment of a first-innings lead, multinomial logistic regression techniques are applied to explore further how these factors critically affect outcomes of test-matches. It is established that in test cricket a team’s first-innings batting and bowling strength, first-innings lead, batting order and home advantage are strong predictors of a winning match outcome. Contrary to popular opinion, it is found that the team batting second in a test enjoys a significant advantage. Notably, the relative superiority of teams during the fourth innings of a test-match, but not the third innings, is a strong predictor of a winning outcome. There is no evidence to suggest that teams generally gained a winning advantage as a result of winning the toss.
Chagas' disease parasite promotes neuron survival and differentiation through TrkA nerve growth factor receptor
Authors: Chuenkova Marina V. , PereiraPerrin Mercio 
Published: September 2004

AbstractTrkA is a receptor tyrosine kinase activated primarily by nerve growth factor (NGF) to regulate differentiation, survival, and other important functions of neurons. Given the critical role TrkA plays in neural maintenance, it may be that microbial invaders of the nervous system utilize this receptor to reduce tissue damage for maximizing host‐parasite equilibrium. Candidate pathogens could be those, like Trypanosoma cruzi, which may produce relatively little brain or nerve damage in long‐lasting infections. We show here that T. cruzi, via its neuraminidase, binds TrkA in a NGF‐inhibitable manner, induces TrkA autophosphorylation, and, through TrkA‐dependent mechanisms, triggers phosphatidylinositol 3‐kinase (PI3K)/Akt kinase signaling, cell survival, and neurite outgrowth. Unlike NGF, the neuraminidase does not react with the apoptosis‐causing pan‐neurotrophin receptor p75NTR. Therefore, these studies identify a novel and unique TrkA ligand in a microbial invader of the nervous system, raising the thus far unsuspected prospect of TrkA underlying clinical progression of an important human infectious disease.