bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brain‐derived neurotrophic factor enhances fetal respiratory rhythm frequency in the mouse preBötzinger complex in vitro
Authors: Bouvier Julien , Autran Sandra , Dehorter Nathalie , Katz David M. , Champagnat Jean , Fortin Gilles , Thoby‐Brisson Muriel 
Published: July 2008

AbstractBrain‐derived neurotrophic factor (BDNF) is required during the prenatal period for normal development of the respiratory central command; however, the underlying mechanisms remain unknown. To approach this issue, the present study examined BDNF regulation of fetal respiratory rhythm generation in the preBötzinger complex (preBötC) of the mouse, using transverse brainstem slices obtained from prenatal day 16.5 animals. BDNF application (100 ng/mL, 15 min) increased the frequency of rhythmic population activity in the preBötC by 43%. This effect was not observed when preparations were exposed to nerve growth factor (100 ng/mL, 30 min) or pretreated with the tyrosine kinase inhibitor K252a (1 h, 200 nm), suggesting that BDNF regulation of preBötC activity requires activation of its cognate tyrosine receptor kinase, TrkB. Consistent with this finding, single‐cell reverse transcription‐polymerase chain reaction experiments showed that one third of the rhythmically active preBötC neurons analysed expressed TrkB mRNA. Moreover, 20% expressed BDNF mRNA, suggesting that the preBötC is both a target and a source of BDNF. At the network level, BDNF augmented activity of preBötC glutamatergic neurons and potentiated glutamatergic synaptic drives in respiratory neurons by 34%. At the cellular level, BDNF increased the activity frequency of endogenously bursting neurons by 53.3% but had no effect on basal membrane properties of respiratory follower neurons, including the Ih current. Our data indicate that BDNF signalling through TrkB can acutely modulate fetal respiratory rhythm in association with increased glutamatergic drive and bursting activity in the preBötC.
The insulin‐regulated aminopeptidase IRAP is colocalised with GLUT4 in the mouse hippocampus – potential role in modulation of glucose uptake in neurones?
Authors: Fernando Ruani N. , Albiston Anthony L. , Chai Siew Y. 
Published: July 2008

AbstractIt is proposed that insulin‐regulated aminopeptidase (IRAP) is the site of action of two peptides, angiotensin IV and LVV‐hemorphin 7, which have facilitatory effects on learning and memory. In fat and muscles, IRAP codistributes with the insulin‐responsive glucose transporter GLUT4 in specialised vesicles, where it plays a role in the tethering and/or trafficking of these vesicles. This study investigated whether an analogous system exists in two functionally distinct regions of the brain, the hippocampus and the cerebellum. In the hippocampus, IRAP was found in the pyramidal neurones where it exhibited a high degree of colocalisation with GLUT4. Consistent with the role of GLUT4 in insulin‐responsive tissues, the glucose transporter was thought to be responsible for facilitating glucose uptake into these pyramidal neurones in response to potassium‐induced depolarisation or cAMP activation as the glucose influx was sensitive to indinavir treatment. Angiotensin IV and LVV‐hemorphin 7 enhanced this activity‐dependent glucose uptake in hippocampal slices. In contrast, in the cerebellum, where the distribution of IRAP was dissociated from GLUT4, the effect of the peptides on glucose uptake was absent. We propose that the modulation of glucose uptake by angiotensin IV and LVV‐hemorphin 7 is region‐specific and is critically dependent on a high degree of colocalisation between IRAP and GLUT4. These findings also confirm a role for IRAP and GLUT4 in activity‐dependent glucose uptake in hippocampal neurones.
Enhanced long‐term potentiation and impaired learning in phosphodiesterase 4D‐knockout (PDE4D−/−) mice
Authors: Rutten Kris , Misner Dinah L. , Works Melissa , Blokland Arjan , Novak Thomas J. , Santarelli Luca , Wallace Tanya L. 
Published: July 2008

AbstractElevation of intracellular cyclic adenosine monophosphate (cAMP) concentrations and subsequent regulation of downstream target gene expression through phosphorylation of cAMP‐responsive element binding protein (CREB) is hypothesized to underlie the mechanism(s) of long‐term memory (LTM) formation. The phosphodiesterase 4 (PDE4) enzyme family is believed to play a key role in LTM by regulating cAMP levels. Thus far, four PDE4 isoforms have been identified (PDE4A, B, C and D); however, the requisite involvement of each of these isoforms in mediating LTM has yet to be elucidated. In the present study, genetic knockout mice were used to investigate the involvement of the PDE4D isoform in both in vitro and in vivo models of learning and memory. Hippocampal synaptic transmission measured electrophysiologically in CA1 slice preparations was similar between wild‐type and PDE4D −/− mice yet, relative to wild‐type controls, knockout mice displayed enhanced early long‐term potentiation (LTP) following multiple induction protocols. Interestingly, the PDE4D −/− animals exhibited significant behavioral deficits in associative learning using a conditioned fear paradigm as compared with control littermates. The impairment in fear conditioning observed in the PDE4D −/− mice could not be attributed to differences in acquisition of the task, alterations in locomotor activity or effects on shock sensitivity. Overall, the in vitro and in vivo alterations in synaptic plasticity observed in the PDE4D −/− mice may be explained by adaptive responses occurring throughout development, and suggest that the PDE4D isoform may be an important mediator of LTM formation.
Task‐irrelevant visual letters interact with the processing of speech sounds in heteromodal and unimodal cortex
Authors: Blau Vera , Van Atteveldt Nienke , Formisano Elia , Goebel Rainer , Blomert Leo 
Published: July 2008

AbstractLetters and speech sounds are the basic units of correspondence between spoken and written language. Associating auditory information of speech sounds with visual information of letters is critical for learning to read; however, the neural mechanisms underlying this association remain poorly understood. The present functional magnetic resonance imaging study investigates the automaticity and behavioral relevance of integrating letters and speech sounds. Within a unimodal auditory identification task, speech sounds were presented in isolation (unimodally) or bimodally in congruent and incongruent combinations with visual letters. Furthermore, the quality of the visual letters was manipulated parametrically. Our analyses revealed that the presentation of congruent visual letters led to a behavioral improvement in identifying speech sounds, which was paralleled by a similar modulation of cortical responses in the left superior temporal sulcus. Under low visual noise, cortical responses in superior temporal and occipito‐temporal cortex were further modulated by the congruency between auditory and visual stimuli. These cross‐modal modulations of performance and cortical responses during an unimodal auditory task (speech identification) indicate the existence of a strong and automatic functional coupling between processing of letters (orthography) and speech (phonology) in the literate adult brain.
Dorsolateral prefrontal lesions do not impair tests of scene learning and decision‐making that require frontal–temporal interaction
Authors: Baxter Mark G. , Gaffan David , Kyriazis Diana A. , Mitchell Anna S. 
Published: July 2008

AbstractTheories of dorsolateral prefrontal cortex (DLPFC) involvement in cognitive function variously emphasize its involvement in rule implementation, cognitive control, or working and/or spatial memory. These theories predict broad effects of DLPFC lesions on tests of visual learning and memory. We evaluated the effects of DLPFC lesions (including both banks of the principal sulcus) in rhesus monkeys on tests of scene learning and strategy implementation that are severely impaired following crossed unilateral lesions of frontal cortex and inferotemporal cortex. Dorsolateral lesions had no effect on learning of new scene problems postoperatively, or on the implementation of preoperatively acquired strategies. They were also without effect on the ability to adjust choice behaviour in response to a change in reinforcer value, a capacity that requires interaction between the amygdala and frontal lobe. These intact abilities following DLPFC damage support specialization of function within the prefrontal cortex, and suggest that many aspects of memory and strategic and goal‐directed behaviour can survive ablation of this structure.
Regulation of motor pattern frequency by reversals in proprioceptive feedback
Authors: Smarandache Carmen R. , Daur Nelly , Hedrich Ulrike B. S. , Stein Wolfgang 
Published: July 2008

AbstractProprioceptive sensory feedback has important functions for motor pattern generation in which phasic negative and positive feedback is used to coordinate neural and musculoskeletal dynamics. Whether and how feedback sign regulates the motor patterns in behaviorally relevant closed‐loop conditions has not been fully elucidated. We characterized the feedback provided by the anterior gastric receptor (AGR), a muscle tendon organ in the stomatogastric nervous system of the crab Cancer pagurus, to the gastric mill motor pattern in intact animals. AGR innervates the protractor muscles and was activated either during the protraction or retraction phase of the rhythm. Experiments with neuromuscular preparations imply that this was due to isometric contractions of the protractor muscles and their passive stretch by the antagonistic retractor muscles. As AGR excited the protractors and inhibited the retractors independently of the timing of its activation, the timing switch changed AGR feedback from positive to negative. We tested the effects of this change in feedback sign on the motor pattern in the isolated nervous system by activating AGR at the corresponding phases of the rhythm, using intracellular current injection. When AGR was activated during the protractor phase and provided positive feedback, it prolonged the burst activities of protractor and retractor neurons and slowed ongoing rhythms. When activated during the retraction phase and thus provided negative feedback, burst durations decreased and the rhythm cycle frequency increased. Our study thus shows that the cycle frequency of centrally generated activity patterns can be regulated by switching the sign of phasic proprioceptive feedback.
Glutamine‐induced membrane currents in cultured rat hippocampal neurons
Authors: Kolbaev Sergej , Draguhn Andreas 
Published: July 2008

AbstractGlutamine is present at high concentrations in the extracellular fluid of the brain. It shuttles between glia cells and neurons, and serves as a precursor for both glutamate and γ‐amino butyric acid. Direct actions of glutamine at central neurons are, however, not well understood. Here we showed thatl‐glutamine (0.5–10 mm) evoked a dose‐dependent inward transmembrane current in primarily cultured rat hippocampal neurons. Typical responses were outwardly rectifying and had a reversal potential around 0 mV. The current was partially sensitive towards blockers of ionotropic glutamate receptors and was partially carried by activation ofN‐methyl‐d‐aspartate receptors. However, cellular responses tol‐glutamine showed clear biophysical and pharmacological differences tol‐glutamate‐evoked currents. Responses were highly specific forl‐glutamine and no responses could be evoked byd‐glutamine,l‐alanine,l‐valine,l‐leucine and the system‐A‐specific agonist α‐(methylamino)‐isobutyric acid. Together, these data indicate that hippocampal neurons can be depolarized by electrogenic effects specific forl‐glutamine.
Direct Stenting after Thrombus Removal before Primary Angioplasty in Acute Myocardial Infarction
Authors: SILVA‐ORREGO PEDRO , BIGI RICCARDO , COLOMBO PAOLA , DE MARCO FEDERICO , OREGLIA JACOPO ANDREA , KLUGMANN SILVIO , GREGORI DARIO 
Published: July 2008

Objectives:

To verify whether direct stenting (DS) after thrombus removal during primary angioplasty (PPCI) in patients with ST‐elevation acute myocardial infarction (STEMI) can improve myocardial reperfusion and prevent distal embolization compared to conventional stent implantation.
Background:

Both mechanical removal and DS reduce thrombus dislodgment and improve microcirculatory reperfusion during PPCI. However, the additional effect of DS after thrombus removal has not been definitely assessed.
Methods:

The DEAR‐MI study included 148 consecutive STEMI patients who were randomly assigned to undergo or not thrombus aspiration before PPCI. For the purpose of the present study, we interrogated the DEAR‐MI data bank to compare the occurrence of complete (>70%) ST‐segment resolution (STR), myocardial blush grade (MBG)‐3, no‐reflow, and angiographic embolization in patients treated and untreated with DS.
Results:

Clinical and angiographic characteristics were similar in the two groups. Comparing DS and no‐DS groups, complete STR was found in 67% versus 51% (P = 0.08), MBG‐3 in 86% versus 49% (P < 0.001), no‐reflow in 1% versus14% (P < 0.01), angiographic embolization in 3% versus 19% (P < 0.01), TIMI flow‐3 in 89% versus 70% (P < 0.01), and the corrected TIMI frame count was 16.2 versus 18.8 (P < 0.05). Among patients undergoing thrombus aspiration, the odds ratio of DS for MBG‐3 and distal embolization was 4 (95% CI 1–16.6) and 0.10 (95% CI 0.01–0.93), respectively. At multivariable analysis, thrombus aspiration (P < 0.001) and DS (P < 0.05) independently predicted MBG‐3, while thrombus aspiration was the only independent predictor of DS.
Conclusions:

DS during PPCI reduces distal embolization and improves myocardial reperfusion. This effect is significantly more relevant after thrombus aspiration.
Consistency of reported tanning behaviors and sunburn history among sorority and fraternity students
Authors: Dennis Leslie K. , Kim Yoonsang , Lowe John B. 
Published: July 2008

Background:Reliable measurements of behavior are crucial to evaluating health promotion efforts. The goal of this reliability study was to examine the consistency of recalled tanning behaviors in a population with a potentially high use.Methods:We used the test–retest reliability of a self‐administered survey to examine the consistency of reporting behavior patterns regarding artificial ultraviolet (UV) tanning, sunburns and sun sensitivity among sorority‐ and fraternity‐affiliated university students.Results:High reliability on test–retest for questions evaluating the number of artificial UV tanning sessions and the number of sunburns during specific time periods was found.Conclusions:Overall, this study suggests that this sub‐population of 18–23‐year‐olds, with a wider range of exposures than other 18–23‐year‐olds and older subjects, report lifetime artificial UV tanning consistently when required to recall time period‐specific exposures before estimating their lifetime exposure.
Rates of allergic sensitization and irritation to oxybenzone‐containing sunscreen products: a quantitative meta‐analysis of 64 exaggerated use studies
Authors: Agin Patricia P. , Ruble Karen , Hermansky Steven J. , McCarthy Timothy J. 
Published: July 2008

Background/purpose: Oxybenzone is an active ingredient found in sunscreen products that absorbs a broad spectrum of ultraviolet (UV) light, with absorbance peaking in the UVB region and extending into the UVA region. Although the overall incidence of sensitization and irritation associated with oxybenzone in the general population remains unclear, a few studies have reported on the incidence in specific circumstances. However, the relevance of these studies to the general population is limited, because the sample populations reported in these papers generally have consisted of individuals who sought medical attention for pre‐existing skin conditions. Therefore, the reported incidence of allergic reactions to oxybenzone in these studies may be overestimated as related to the general population. The objective of this meta‐analysis was to determine the safety of oxybenzone in participants recruited from the general population.Methods: The data from 64 unpublished exaggerated use human repeat insult patch tests (HRIPT) and photoallergy (PA) studies sponsored by Schering‐Plough HealthCare Products Inc. between 1992 and 2006 were aggregated and analyzed to evaluate the irritancy and sensitization potential of sunscreen products containing oxybenzone at concentrations between 1% and 6%.Results: Forty‐eight of 19 570 possible dermal responses were considered to be suggestive of irritation or sensitization; the mean rate of responses across all formulations was 0.26%. Sensitization rates did not correlate significantly with oxybenzone concentration. The available re‐challenge data indicated that only eight of these responses were contact allergies from oxybenzone, and the mean rate of contact allergy to oxybenzone was 0.07%. The source of the skin responses was not confirmed for 15 subjects who were lost to follow‐up. However, all subjects were given the opportunity to participate in follow‐up testing.Conclusion: Our data indicate that sunscreen products formulated with 1–6% oxybenzone do not possess a significant sensitization or irritation potential for the general public. Furthermore, these data suggest that the incidence rate implied in the published literature overestimates the actual incidence of sensitization/irritation due to oxybenzone‐containing sunscreen products in the general population.
Sunscreens containing the broad‐spectrum UVA absorber, Mexoryl® SX, prevent the cutaneous detrimental effects of UV exposure: a review of clinical study results
Authors: Fourtanier Anny , Moyal Dominique , Seité Sophie 
Published: July 2008

Background: UVA exposure of human skin mainly produces reactive oxygen species (ROS) leading to DNA, cell and tissue damage. It alters immune function, pigmentation and it is certainly responsible for a large part of photoaging changes. Moreover UVA is implicated in the etiology of several photodermatoses. As a consequence, to provide adequate protection, sunscreens or skin care products for daily use protective products need UVA absorbers combined with UVB ones.Aim: To assess the efficacy of sunscreens containing a broad‐spectrum UVA absorber the Mexoryl® SX or ecamsule and to compare formulations with and without it through a large number of clinical studies in human volunteers and patients.Methods: The following assessments were conducted:

Prevention of excessive pigmentation induced by UV exposure in Caucasian and Asian skins using a method that measures pigmentation protection factors (PPF).
Efficacy against DNA damage by measurement of pyrimidine dimer formation and p53 protein accumulation.
Protection of immune system using delayed type hypersensitivity (DTH) reactions to recall antigens, isomerization of urocanic acid (UCA), alteration of Langerhans cells (LC) density, morphology and function.
Reduction of epidermal and dermal alterations induced by repeated UVA or UV solar simulated radiation (SSR) using histology or immunohistology.
Prevention of the polymorphous light eruption (PMLE) in patients prone to develop this disease.

Results: Mexoryl® SX‐containing formulations showed a dose‐dependent level of protection against pigmentation. For a same sun protection factor (SPF) the higher the UVA protection was, the higher was the PPF. Pyrimidine dimer formation and p53 accumulation were significantly reduced by formulations with Mexoryl® SX. In the studies looking at the suppression of DTH reactions to recall antigens by the different UV spectra, the LC alterations and the cis UCA formation, Mexoryl® SX formulations always showed a higher protective potency than sunscreen without it even when the protection against erythema was similar (products with same SPF). Mexoryl® SX formulations also prevented or significantly decreased to minimal, ferritin, tenascin and lysozyme expression induced by repeated UVA or SSR exposure. It also reduced the enhancement of collagenase 2 mRNA expression induced by SSR exposure. Finally PMLE study demonstrated that UVA protection was essential for the prevention of this photodermatose.Conclusion: Mexoryl® SX formulated in sunscreens or daily use products have been shown to be an effective UV absorber, leading to an increased efficacy of these products against a large number of biological damage induced by UVA, SSR or sun exposure.
Effects of Dietary Binders on Survival and Growth Performance of Postlarval Tongue Sole, Cynoglossus semilaevis (Günther)
Authors: Liu Feng , Ai Qinghui , Mai Kangsen , Tan Beiping , Ma Hongming , Xu Wei , Zhang Wenbing , LiuFu Zhiguo 
Published: July 2008

Abstract A 30‐d feeding experiment was conducted in tanks to investigate the effects of four different binders (2% in microdiet) on the survival, growth performance, and specific activity of digestive enzymes in tongue sole, Cynoglossus semilaevis Günther, postlarvae (24 d after hatching, with initial average wet weight of 22.4 ± 6.65 mg [mean ± SD]). Five approximately isonitrogenous and isoenergetic microbound diets were formulated with carrageenan (Car), sodium carboxymethylcellulose (CMS), sodium alginate (SA), and gelatin (Gel) as binders, and a diet with no special binder as a control. A commercial diet (RQ Com., manufactured by Marubeni Nisshin Feed Co., Ltd., Chita, Japan) was used as another tested diet, and Artemia nauplii was used as live prey control. The results showed that the survival of the fish fed SA diet (31.3%) was significantly higher than that of fish fed CMS (21.8%), Car (10.8%), and control (21.8%) diets (P < 0.05), but significantly lower than that of the fish fed the live prey (54.5%) diet (P < 0.05). The results of growth followed the similar pattern as that of survival, although there were no significant differences in specific growth rate (SGR) among fish fed SA, CMS, Gel, the control, and RQ diets (7.2, 6.8, 7.0, 6.9, and 7.3% per day; P > 0.05). However, fish fed Car diet had a significantly lower SGR (5.9% per day) than fish fed other diets. Percentages of secreted amylase in fish fed artificial diets were not significantly different, but fish fed artificial diets had significantly higher (P < 0.05) secreted amylase than live prey group. Percentage of secreted trypsin in fish fed SA diet (54.9%) was relatively higher compared with other binders, and not significantly different from RQ Com. and live prey treatments. However, trypsin in fish fed Car diets (29.3%) was significantly lower than in other groups. Specific activities of alkaline phosphatase (AP) in the intestine and AP and leucine aminopeptidase N in brush border membranes in fish fed SA diet (264.6, 1882.8, and 187.2 mU/mg protein) were relatively higher compared with other binders. These results indicate that SA is one of suitable binders compared with carrageenan, CMS, and gelatin in microdiet of postlarval tongue sole.