bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sildenafil reduces L‐NAME‐induced severe hypertension and worsening of myocardial ischaemia–reperfusion damage in the rat
Authors: Rossoni G , Manfredi B , De Gennaro Colonna V , Berti M , Guazzi M , Berti F 
Published: January 2007

Background and purpose:Phosphodiesterase‐5 inhibitors are beneficial in pulmonary hypertension and congestive heart failure, the two conditions associated with coronary heart disease and ischaemia. We investigated whether sildenafil counteracts the cardiovascular alterations induced by N
ω‐nitro‐L‐arginine methyl ester (L‐NAME) in the rat.Experimental approach:Sildenafil was given orally to rats at doses of 0.37, 0.75 or 1.5 mg kg−1day−1 for four weeks, either alone or with L‐NAME (35‐40 mg kg−1 day−1 in the drinking water). Systolic blood pressure and urinary parameters (6‐keto‐prostaglandin F1α, thromboxane B2, 8‐isoprostane‐prostaglandin F2α and nitrite/nitrate) were measured in conscious rats. Isolated hearts were subjected to low flow ischaemia–reperfusion, and myocardial levels of guanosine 3′, 5′cyclic monophosphate (cGMP) were determined. Endothelial vascular dysfunction was examined in aortic rings.Key results:Sildenafil dose‐dependently prevented the rise in systolic blood pressure in L‐NAME‐treated rats. This activity was associated with a normalization of urinary 8‐isoprostane‐prostaglandin F2α and other biochemical parameters. In perfused hearts, the post‐ischaemic ventricular dysfunction was worse in preparations from L‐NAME‐treated rats than in controls. Sildenafil dose‐dependently reduced this effect, and creatine kinase and lactate dehydrogenase release were lower too. cGMP levels, which were low in myocardial tissue from L‐NAME‐treated rats, were restored by sildenafil. In noradrenaline‐precontracted aortic rings from L‐NAME‐treated rats acetylcholine lost its vasorelaxant effect, and sildenafil restored it.Conclusion and implications:In a rat model of chronic nitric oxide deprivation, where hypertension and aggravation of post‐ischaemic ventricular dysfunction are associated with loss of vascular endothelium‐relaxant function, sildenafil provided significant cardiovascular protection, primarily by maintaining tissue cGMP levels.British Journal of Pharmacology (2007) 150, 567–576. doi:10.1038/sj.bjp.0707131
The Dependence of Monocular Rivalry on Orientation
Authors: Campbell F W , Gilinsky A S , Howell E R , Riggs L A , Atkinson J 
Published: January 2007

If two gratings with a sinusoidal luminance profile are crossed and if each has a different colour then they are seen to alternate; first one dominates and then the other. Part of the time both are seen. The rate of this monocular rivalry varies with the angle between the two gratings. If the two are lined up in parallel the percept is quite stable and remains so until their orientation is about 15° to 20° apart. The rate of alternation then increases rapidly reaching a maximum rate of 30 per minute. The orientational selectivity of the rivalry suggests that the orientational properties of the neurones in the visual cortex discovered by Hubel and Wiesel are involved. Acknowledgements. We wish to thank Professor Peter M. Milner for his keen interest in these experiments and for acting as a subject. F.W.C. is supported by a grant from the Medical Research Council. The work of A.S.G. during her visit to Cambridge was supported in part by a research grant GB-31029 from the National Science Foundation. E.R.H. was awarded a Wellcome Trust Fellowship while in Cambridge.
The Process of ‘Taking-into-Account’ in Visual Perception
Authors: Epstein W 
Published: January 2007

In order to secure useful information the perceptual system must combine information present in the retinal counterpart of the to-be-discriminated distal variable with information about other variables that affect the state of the retinal counterpart. This combinatorial process may be called—following Woodworth's lead—the process of ‘taking-into-account’. Seven applications of the ‘taking-into-account’ hypothesis are described. Salient features of the hypothesis are examined and the empirical status of the hypothesis is summarized and evaluated. Finally a model of the information-processing sequence suggested by the hypothesis is presented.
‘Where’ and ‘What’ in Visual Search
Authors: Atkinson Janette , Braddick Oliver J 
Published: January 2007

A line segment target can be detected among distractors of a different orientation by a fast ‘preattentive’ process. One view is that this depends on detection of a ‘feature gradient’, which enables subjects to locate where the target is without necessarily identifying what it is. An alternative view is that a target can be identified as distinctive in a particular ‘feature map’ without subjects knowing where it is in that map. Experiments are reported in which briefly exposed arrays of line segments were followed by a pattern mask, and the threshold stimulus-mask interval determined for three tasks: ‘ what’—subjects reported whether the target was vertical or horizontal among oblique distractors; ‘ coarse where’—subjects reported whether the target was in the upper or lower half of the array; ‘ fine where’—subjects reported whether or not the target was in a set of four particular array positions. The threshold interval was significantly lower for the ‘coarse where’ than for the ‘what’ task, indicating that, even though localization in this task depends on the target's orientation difference, this localization is possible without absolute identification of target orientation. However, for the ‘fine where’ task, intervals as long as or longer than those for the ‘what’ task were required. It appears either that different localization processes work at different levels of resolution, or that a single localization process, independent of identification, can increase its resolution at the expense of processing speed. These possibilities are discussed in terms of distinct neural representations of the visual field and fixed or variable localization processes acting upon them.
Perceived Rigidity and Nonrigidity in the Kinetic Depth Effect
Authors: Ganis Giorgio , Casco Clara , Roncato Sergio 
Published: January 2007

Stroboscopic simulations of three-dimensional rotating rigid structures can be perceived as highly nonrigid. To investigate this nonrigidity effect a sequence of either three (experiment 2 and 3) or thirty six frames (experiment 4) was used, each consisting of a set of dots with location on the horizontal axis corresponding to the parallel projection of a nominally defined helix. Observers were asked to judge the angle of rotation of eighty helices defined by the factorial combination of eight phase (φ) values (ie difference between the sinusoidal path of one dot and its neighbours) and ten different angular displacement values (α). When in each static frame the dots can be organized into curved dotted line (small values of φ), the perceived 3-D helices are highly nonrigid. But when shape information is not available in each static frame (high values of φ), the helices are perceived as rigid and rotation judgement is possible providing that α < 15°. It appears that at small values of φ observers fail to recover the rigid structure of the helices since the input to the structure from the motion process may be distorted.
Asymmetries in the Sensitivity to Motion in Depth: A Centripetal Bias
Authors: Edwards Mark , Badcock David R 
Published: January 2007

It is reasonable to ask whether observers are more sensitive to the pattern of image motion caused by forward locomotion through the environment than to the pattern caused by backward locomotion. The distribution of sensitivities of cells in MT does show such a bias, although this bias is minimal at small eccentricities. Additionally, both locomotion-induced stimulation and the sensitivities of MT cells suggest greater sensitivity should be obtained in the lower visual field. Previous research on this issue has usually employed frontoparallel motion in patterns presented to one side of the fixation point. Both centrifugal and centripetal biases have been obtained. In this study the stimuli present motion signals that travel radially from (or towards) the fixation point. These stimuli, which produce a strong percept of motion in depth, are an adaptation of the global-dot-motion stimulus employed by Newsome and Pare. With these stimuli we find that sensitivity to motion in depth is greater in the lower visual field than in the upper visual field, and that sensitivity is greater to centripetal motion than to either centrifugal or frontoparallel motion. This centrifugal bias in sensitivity decreases with eccentricity. The last two findings contradict the notion that the bias is produced by the visual experience induced by normal forward locomotion and also that the detection of motion in depth is subserved by MT.
Lysine 58‐cleaved β2‐microglobulin is not detectable by 2D electrophoresis in ex vivo amyloid fibrils of two patients affected by dialysis‐related amyloidosis
Authors: Giorgetti Sofia , Stoppini Monica , Tennent Glenys A. , Relini Annalisa , Marchese Loredana , Raimondi Sara , Monti Maria , Marini Sara , Østergaard Ole , Heegaard Niels H.H. , Pucci Piero , Esposito Gennaro , Merlini Giampaolo , Bellotti Vittorio 
Published: January 2007

AbstractThe lysine 58 cleaved and truncated variant of β2‐microglobulin (ΔK58‐β2m) is conformationally unstable and present in the circulation of a large percentage of patients on chronic hemodialysis, suggesting that it could play a role in the β2‐microglobulin (β2m) amyloid fibrillogenesis associated with dialysis‐related amyloidosis (DRA). However, it has yet to be detected in the amyloid deposits of such patients. Here, we extracted amyloid fibrils, without denaturation or additional purification, from different amyloidotic tissues of two unrelated individuals suffering from DRA, and characterized them by high‐sensitivity bidimensional gel electrophoresis (2D‐PAGE), immunoblotting, MALDI time‐of‐flight mass spectrometry, and protein sequencing. To confirm whether or not this species could be identified by our proteomic approaches, we mapped its location in 2D‐PAGE, in mixtures of pure ΔK58‐β2m, and extracts of amyloid fibrils from patients, to a discrete region of the gel distinct from other isoforms of β2m. Using this approach, the two known principal isoforms found in β2m amyloid were identified, namely, the full‐length protein and the truncated species lacking six N‐terminal amino acid residues (ΔN6‐β2m). In contrast, we found no evidence for the presence of ΔK58‐β2m.
Identification of a plane pollen lipid transfer protein (Pla a 3) and its immunological relation to the peach lipid‐transfer protein, Pru p 3
Authors: Lauer I. , Miguel‐Moncin M. S. , Abel T. , Foetisch K. , Hartz C. , Fortunato D. , Cistero‐Bahima A. , Vieths S. , Scheurer S. 
Published: January 2007

SummaryBackground
An association between plane tree pollen allergy and plant food allergy has been described, but the cross‐reacting allergens have not yet been identified. The aim of this study was the identification of homologous non‐specific lipid‐transfer proteins (nsLTPs) in plane pollen, and to investigate its immunological relationship with the peach LTP, Pru p 3.Methods
Three different patient groups were recruited in Spain: 22 plane pollen‐allergic patients without food allergy (A), 36 plane pollen‐allergic patients with peach allergy (B) and 10 peach‐allergic patients without plane pollen allergy (C). Proteins from plane pollen extract were fractionated by ion‐exchange and reversed‐phase chromatography. Further methods applied were N‐terminal amino acid sequence analysis, immunoblotting, enzyme allergosorbent test, CAP and basophil histamine release assays.Results
A 10 kDa IgE‐reactive protein was purified from plane pollen and identified as nsLTP. Pla a 3 was characterized as a minor allergen (27.3%) in plane pollen‐allergic patients without food allergy (A) and as a major allergen in plane pollen‐allergic patients with peach allergy (B) showing a prevalence of IgE‐reactivity of 63.8%. Group B contained patients sensitized to Pru p 3 without IgE‐reactivity to plane‐LTP (16.6%). By contrast, Pla a 3 IgE‐reactive patients without sensitization to Pru p 3 could be found (16.6%). The sera of patients sensitized to both LTPs (50%), Pla a 3 and Pru p 3, showed different biological activity in histamine release assay: depending on individual patient's sera tested, Pla a 3 showed a similar, a stronger or a weaker allergenic potency in comparison with Pru p 3.Conclusions
Plane LTP is a major allergen in plane pollen‐allergic patients with peach allergy recruited in the Mediterranean area. The results of histamine release tests and different IgE‐binding profiles pointed towards the existence of species‐specific IgE epitopes. Likewise, no general conclusion on the sensitizer could be made.
Sedation of neurologically impaired children undergoing MRI: a sequential approach
Authors: CORTELLAZZI PAOLO , LAMPERTI MASSIMO , MINATI LUDOVICO , FALCONE CHIARA , PANTALEONI CHIARA , CALDIROLI DARIO 
Published: January 2007

SummaryBackground:  The purpose of this retrospective study was to determine the efficacy of a sequential approach meant to rescue failed chloral hydrate sedation and to obtain a low rate of adverse events along with predictable timings in neurologically impaired children undergoing magnetic resonance imaging.Methods:  We retrospectively evaluated 1104 chloral hydrate sedations performed between 2002 and 2004 on 862 children weighing <26 kg. If the desired sedation score (3 on the Skeie Scale) was not reached within 30 min after oral administration of chloral hydrate, sedation was considered as potentially failed, and supplementation with sevoflurane, i.m. or i.v. ketamine, and i.v. pentobarbital and midazolam was started.Results:  Twenty‐seven sessions failed because of excessive movement. Mean induction time was significantly higher for patients who received supplementation (52.2 min vs 39.1 min), while no differences in recovery and total sedation times were found. Supplementation significantly increased the incidence of respiratory obstruction (4.6% vs 2.4%), although the incidence of other adverse events was unaffected.Conclusions:  Administering up to 1.5 g of chloral hydrate without supplementation was associated with a failure rate of approximately 20%, but the proposed sequential approach enabled us to rescue the majority of failed sedations while maintaining an acceptably low incidence of adverse events.
Is a fall in baseline heart rate a reliable predictor of a successful single shot caudal epidural in children?
Authors: GHAI BABITA , MAKKAR JEETINDER KAUR , BEHRA BIKRAM KISHORE , RAO KRISHNA PRASAD 
Published: January 2007

SummaryBackground:  This study was designed to investigate whether a fall in heart rate (HR) with injection of local anesthetic into the caudal space can be used as a predictor of correct needle placement.Methods:  Two hundred and twenty pediatric patients undergoing infraumbilical surgery were recruited to the study. After induction of general anesthesia, baseline HR was recorded and caudal block was performed using 0.75–1 ml·kg−1 0.25% bupivacaine, which was injected at a rate of 1 ml·3 s−1. The change in HR while injecting an initial 0.2 ml·kg−1 of drug and during total drug injection was recorded. HR reduction of ≥3 b·min−1 was considered a positive test for correct needle placement. The success of block was judged by HR response to skin incision, endtidal halothane concentration required for maintenance of anesthesia and postoperative pain scores.Results:  Caudal block was successful in 209/220 (95%) patients. Mean HR following the initial drug injection (111 ± 17.7, P < 0.01) and entire drug injection (108.8 ± 17.2, P < 0.01) was significantly lower than baseline (116.2 ± 17.5). HR reduction of ≥3 b·min−1 was present in 190/209 and 199/209 successful block following initial drug injection and total drug injection respectively. The analysis of study data showed that a fall in HR is a predictor of successful caudal block, with a sensitivity of 90.9%, specificity of 100% and a positive predictive value of 100% after initial injection of local anesthetic.Conclusions:  We conclude that decrease in HR with drug injection is a simple, objective and reliable test to predict success of caudal block.
Effects of preanesthetic administration of midazolam, clonidine, or dexmedetomidine on postoperative pain and anxiety in children
Authors: SCHMIDT ANDRÉ P. , VALINETTI EMILIA A. , BANDEIRA DENISE , BERTACCHI MARIA F. , SIMÕES CLÁUDIA M. , AULER JOSÉ OTÁVIO C. 
Published: January 2007

SummaryBackground:  A growing interest in the possible influences of pre‐ and postoperative anxiety and pain scores as outcomes of surgical treatment and benefits of anxiety or pain‐reducing interventions has emerged. The aim of this study was to evaluate the influence of three different premedication regimens on postoperative pain and anxiety in children.Methods:  A prospective, randomized, open‐label clinical trial enrolled 60 schoolchildren. They were randomized for premedication with oral midazolam 0.5 mg·kg−1, oral clonidine 4 μg·kg−1, or transmucosal dexmedetomidine (DEX) 1 μg·kg−1, submitted to a pre‐ and postoperative evaluation of anxiety with the State‐Trait Anxiety Inventory for Children and asked to report any pain in verbal and visual analog scales. We also evaluated secondary outcomes such as parents’ anxiety, sedation, separation from parents, adverse effects and hemodynamic status.Results:  Dexmedetomidine and clonidine were related to lower scores of pain than midazolam. α2‐agonists produced lower scores of peroperative mean arterial pressure and heart rate than midazolam. Both groups had similar levels of postoperative state‐anxiety in children. There was no difference in preanesthesia levels of sedation and response to separation from parents between groups.Conclusions:  These findings indicate that children receiving clonidine or DEX preoperatively have similar levels of anxiety and sedation postoperatively as those receiving midazolam. However, children given α2‐agonists had less perioperative sympathetic stimulation and less postoperative pain than those given midazolam.
What's Unique About the Federal Funds Rate? Evidence from a Spectral Perspective*
Authors: Sarno Lucio , Thornton Daniel L. , Wen Yi 
Published: January 2007

AbstractThis paper compares the behaviour of the effective federal funds rate to 10 US interest rates with maturities ranging from overnight to 10 years. Using spectral estimation methods, we identified idiosyncratic shocks to the funds rate and provided evidence on their impact on other rates at various frequencies. Our results suggest that, while all of the interest rates examined have common shocks at low frequencies, the federal funds rate contains some unique information at high frequency, although this information appears to be relevant only at the short end of the term structure. In turn, these results are open to various alternative interpretations.
Nuclear localization of functional metabotropic glutamate receptor mGlu1 in HEK293 cells and cortical neurons: role in nuclear calcium mobilization and development
Authors: Jong Yuh‐Jiin I. , Schwetye Katherine E. , O’Malley Karen L. 
Published: January 2007

AbstractThe Group I metabotropic glutamate receptor (mGlu1) plays an important role in neuromodulation, development, and synaptic plasticity. Using immunocytochemistry, subcellular fractionation, and western blot analysis, the present study shows that mGlu1a receptors are present on nuclear membranes in stably transfected human embryonic kidney 293 (HEK293) cells as well as being endogenously expressed on rat cortical nuclei. Both glutamate and the group I agonist, quisqualate, directly activate nuclear mGlu1 receptors leading to a characteristic oscillatory pattern of calcium flux in isolated HEK nuclei and a slow rise to plateau in isolated cortical nuclei. In either case calcium responses could be terminated upon application of the mGlu1‐selective antagonist, 7‐(hydroxyamino)cyclopropa[b]chromen‐1a‐carboxylate ethyl ester. Responses could also be blocked by ryanodine and inositol 1,4,5‐triphosphate receptor inhibitors, demonstrating the involvement of these calcium channels. Agonist activation of intracellular receptors was driven by Na+‐dependent and ‐independent processes in nuclei isolated from either HEK or cortical neurons. Finally, mGlu1 nuclear receptors were dramatically up‐regulated in the course of post‐natal development. Therefore, like the other Group I receptor, mGlu5, mGlu1 can function as an intracellular receptor, suggesting a more encompassing role for nuclear G protein‐coupled receptors and downstream signaling elements in the regulation of nuclear events.
Characterization of microsatellite markers in the rosewood (Dalbergia monticola Bosser & R. Rabev.)
Authors: FAVREAU BENEDICTE , ANDRIANOELINA OLIVARIMBOLA , NUNEZ PHILIPPE , VAILLANT ALEXANDRE , RAMAMONJISOA LOLONA , DANTHU PASCAL , BOUVET JEAN‐MARC 
Published: January 2007

Abstract Dalbergia monticola is one of the major components of the oriental forest of Madagascar. This economically and ecologically important tree is threatened because of the dramatic decrease of the Madagascar forest. We have estimated the genetic diversity and structure of the species by studying nuclear microsatellites. We have developed eight pairs of primers to analyse 215 individuals distributed from the north to the south of the island. These markers will be useful for genetic and ecological studies of this species.
Control of hydrogen partial pressures on the rates of syntrophic microbial metabolisms: a kinetic model for butyrate fermentation
Authors: JIN Q. 
Published: January 2007

ABSTRACTA new model describing the rate of syntrophic butyrate fermentation is constructed based on a thermodynamically consistent rate law and the metabolic pathway. This model takes into account the mechanism of reverse electron transfer and proposes that the net amount of energy saved by microorganisms as ATP depends on hydrogen partial pressures in the environment. Hydrogen partial pressures thus control not only the energy available in the environment but also the energy conserved by microorganisms. This new model predicts the rates of butyrate fermentation as a product of a kinetic factor and a thermodynamic potential factor: the kinetic factor describes how butyrate concentration controls the rates; the thermodynamic factor accounts for how the thermodynamic driving force controls the rates. Increases in hydrogen partial pressures decrease the energy available, lowering the driving force and fermentation rates. To maintain butyrate fermentation at significant rates, microorganisms decrease the amount of energy conserved, maximizing the driving force. Application of the new model demonstrates that the thermodynamic driving force is a dominant factor in controlling the rates of butyrate fermentation.