bluuebunny/crossref_metadata_2025 huggingface dataset:
Has the BARRIERS Scale changed nursing practice? An integrative review
Authors: Carlson Cathy L. , Plonczynski Donna J.
Published: July 2008

Title.  Has the BARRIERS Scale changed nursing practice? An integrative review.

Aim.  This paper is a report of a review to analyse studies using the BARRIERS Scale to determine (a) if the identification of perceived barriers to research utilization influences nurses’ use of research, (b) if the extent of nurses’ perceived barriers to research utilization and most frequently cited barriers have changed over the past 15 years and (c) if nurses’ most frequently cited barriers to research utilization differ across countries.

Background.  The BARRIERS Scale has been used to identify nurses’ untoward perceptions or barriers to research utilization.

Data sources.  A computer search was conducted using the Cumulative Index of Nursing and Allied Health Literature, MEDLINE, Dissertation Abstracts International and Academic Abstracts to identify relevant literature from 1991 to 2006. The Internet and citations within studies were also searched.

Review methods.  Studies were included if they were in English, used the entire BARRIERS Scale and reported nurses’ responses. Studies were coded for author(s), publication year, country, population, sample size, response rate, the three‐most frequently cited barriers, mean per cent of items rated as moderate or greater, and number of items identified as a barrier by 50% or more of respondents. Quality appraisal of the included papers was not performed.

Results.  Forty‐five studies met the inclusion criteria and predominantly identified the same barriers. No evidence was found that identification of barriers to nurses’ use of research influenced nursing practice.

Conclusions.  It appears that there would be minimal benefit from further descriptive research using the BARRIERS Scale. Research is needed to investigate whether relationships exist between perceptions of barriers to nurses’ use of research and the use evidence‐based practice.
Nursing recruitment: relationship between perceived employer image and nursing employees’ recommendations
Authors: Van Hoye Greet
Published: July 2008

Title.  Nursing recruitment: relationship between perceived employer image andnursing employees' recommendations.

Aim.  This paper is a report of a study to examine the relationship between nursing employees’ perceptions of instrumental and symbolic dimensions of employer image on the one hand and their intentions to recommend their organization as an employer and their willingness to testify in their organization’s recruitment materials on the other.

Background.  Previous research suggests that word‐of‐mouth recommendations by current nursing employees can enhance healthcare organizations’ attractiveness as an employer for potential applicants. However, it is not known what motivates employees to provide positive word‐of‐mouth comments and to endorse their employer in recruitment testimonials.

Method.  The instrumental‐symbolic framework was applied to identify relevant dimensions of perceived employer image that might relate to employee recommendations. A questionnaire was administered in 2006 to 106 nurses and nursing aides from four non‐profit nursing homes in Belgium. The response rate was 55%.

Results.  Overall, nursing employees were more willing to recommend their nursing home to others than to testify in recruitment materials. Both instrumental and symbolic employer image dimensions predicted nursing employees’ recommendation intentions. Conversely, willingness to testify was only predicted by symbolic image dimensions. Specifically, the more the nursing employees perceived that their nursing home offers task diversity, offers the possibility to help people and is prestigious, the more they intended to recommend their organization to others. The more they perceived their nursing home as competent, the higher were their recommendation intentions and their willingness to testify in recruitment communication.

Conclusion.  To increase nursing employees’ willingness to recommend their employer to potential applicants, organizations should enhance their perceived employer image.
Spatially resolved cathodoluminescence of luminescent materials using an EDX detector
Authors: SMET P.F. , VAN HAECKE J.E. , POELMAN D.
Published: July 2008

Panchromatic cathodoluminescence (CL) maps were collected in a scanning electron microscope equipped with an EDX (energy dispersive x‐ray analysis) detector. These CL maps can readily be correlated with elemental maps obtained by EDX. Although EDX detectors are designed to be insensitive to light and therefore not optimized for high sensitivity CL measurements, high‐resolution images can be obtained from luminescent materials without the need for additional hard‐ or software. The method was tested on highly luminescent BaAl2S4 : Eu2+ thin films that have a potential use in flat panel displays. The spectral response and linearity of the overall system was determined by means of monochromatic light sources, illuminating the sample through an optical fibre. We studied the response of the EDX detector to the intensity of the incoming light as well as the influence of the detector settings. The observations were explained by numerical simulations.
Shape normalization of 3D cell nuclei using elastic spherical mapping
Authors: GLADILIN E. , GOETZE S. , MATEOS‐LANGERAK J. , VAN DRIEL R. , EILS R. , ROHR K.
Published: July 2008

Topological analysis of cells and subcellular structures on the basis of image data, is one of the major trends in modern quantitative biology. However, due to the dynamic nature of cell biology, the optical appearance of different cells or even time‐series of the same cell is undergoing substantial variations in shape and texture, which makes a comparison of shapes and distances across different cells a nontrivial task. In the absence of canonical invariances, a natural approach to the normalization of cells consists of spherical mapping, enabling the analysis of targeted regions in terms of canonical spherical coordinates, that is, radial distances and angles. In this work, we present a physically‐based approach to spherical mapping, which has been applied for topological analysis of multichannel confocal laser scanning microscopy images of human fibroblast nuclei. Our experimental results demonstrate that spherical mapping of entire nuclear domains can automatically be obtained by inverting affine and elastic transformations, performed on a spherical finite element template mesh.
Phase resolving microscopy by multi‐plane diffraction detection
Authors: GRJASNOW A. , WUTTIG A. , RIESENBERG R.
Published: July 2008

An easily applicable quantitative phase‐contrast microscopy is presented. A bright‐field microscope with a coherent illumination is used. Only a series of diffraction images is taken in different distances from the sample. For reconstruction, a conjugate gradient technique as a new variant of phase retrieval technique is developed. The technique is experimentally investigated in detail. A phase accuracy up to 0.07 rad or a height accuracy of 13 nm in transmission for a binary test sample is reached, respectively.
Knife‐edge scanning microscopy for imaging and reconstruction of three‐dimensional anatomical structures of the mouse brain
Authors: MAYERICH D. , ABBOTT L. , McCORMICK B.
Published: July 2008

Anatomical information at the cellular level is important in many fields, including organ systems development, computational biology and informatics. Creating data sets at resolutions that provide enough detail to reconstruct cellular structures across tissue volumes from 1 to 100 mm3 has proven to be difficult and time‐consuming. In this paper, we describe a new method for staining and imaging large volumes of tissue at sub‐micron resolutions. Serial sections are cut using an automated ultra‐microtome, whereas concurrently each section is imaged through a light microscope with a high‐speed line‐scan camera. This technique, knife‐edge scanning microscopy, allows us to view and record large volumes of tissue in a relatively small amount of time (approximately 7 mm2 s−1).

 The resolution and scanning speed of knife‐edge scanning microscopy provides a new method for imaging tissue at sufficient resolution to reconstruct maps of cellular distribution and morphology. We show that these techniques preserve the alignment of serial sections accurately enough to allow for reconstruction of neuronal processes and microvasculature. Expanding these techniques to other tissues opens up the possibility of creating fully reconstructed cellular maps of entire organs.
Electronic property investigations of single‐walled carbon nanotube bundles in situ within a transmission electron microscope: an evaluation
Authors: ASLAM Z. , ABRAHAM M. , BROWN A. , RAND B. , BRYDSON R.
Published: July 2008

We have evaluated a combined transmission electron microscopy (TEM)–scanning tunnelling microscopy (STM) (hence TEM‐STM) sample holder for the investigation of the mechanical and electrical properties of individual bundles of single‐walled carbon nanotubes (SWCNTs) together with their simultaneous observation, analysis and mechanical modification in the TEM. Current‐voltage (I–V) measurements from bundles of SWCNTs were observed to change as the bundles were deformed both reversibly and irreversibly, although the observed behaviour was somewhat complex. Electron energy loss spectroscopy (EELS) analysis revealed measurable changes in the bonding of the carbon atoms within the graphene layers upon bundle deformation, with measurable changes in the π*/(π*+σ*) peak ratios observed at the carbon K‐edge. Reversible deformation of the bundles was consistent with the sensitivity of σ bonding to deviations from nonplanarity, whereas irreversible deformation was consistent with the introduction of nonhexagonal defects into the graphene sheets.
Hepatic gas gangrene following orthotopic liver transplantation: three cases treated with re‐transplantation and a review of the literature
Authors: Doblecki‐Lewis S. , Palaios E. , Bejarano P.A. , Tzakis A.G. , Selvaggi G. , Morris M.I.
Published: July 2008

Abstract:Gas gangrene is a rare and devastating infectious process that can occur after liver transplantation, most often following hepatic artery thrombosis. We here report 3 cases of gas gangrene following orthotopic liver transplantation. Blood cultures were positive forClostridium clostridiiformein one case. In 2 other cases liver tissue from explanted specimens was positive forEnterobacter cloacae. Ultrasound demonstrated hepatic artery thrombosis and computed tomography imaging revealed diffuse liver necrosis with gas formation in each case. All 3 patients were successfully treated with a combination of antibiotics and emergent re‐transplantation. We review previously published cases of gas gangrene after liver transplant and emphasize the importance of hepatic artery thrombosis in the development of this syndrome as well as the frequent involvement of non‐clostridial organisms. Early diagnosis and aggressive combined medical and surgical treatment including re‐transplantation are essential for successful treatment of these rare and catastrophic infections.
Varicella zoster virus‐associated disease in adult kidney transplant recipients: incidence and risk‐factor analysis
Authors: Arness T. , Pedersen R. , Dierkhising R. , Kremers W. , Patel R.
Published: July 2008

Abstract: Varicella zoster virus (VZV)‐related disease, particularly herpes zoster, is a complication of organ transplantation due to long‐term immunosuppression. We determined the incidence and risk factors for post‐transplant VZV infection by retrospectively reviewing the medical records of a cohort of 612 adult renal transplant recipients transplanted at Mayo Clinic Rochester between October 1, 2001 and October 1, 2004. Thirty‐seven subjects developed herpes zoster, corresponding to a follow‐up time‐adjusted incidence of 11.2% at 4 years post transplant. The incidence rate of zoster was relatively constant between 6 months and 4 years, yielding an average incidence of approximately 28 per 1000 person‐years. The risk of developing post‐transplant zoster increased with increasing age at transplant, with each decade conferring a 1.42‐fold (P=0.009) increase in risk of zoster development. Seronegativity at time of transplant conferred over 3 times the risk of development of post‐transplant zoster (hazard ratio 3.4; P=0.04) compared with seropositivity. Adult kidney transplant recipients are at high risk for the development of post‐transplant zoster.
Fungal panniculitis in renal transplant recipients
Authors: Bhowmik D. , Dinda A.K. , Xess I. , Sethuraman G. , Mahajan S. , Gupta S. , Agarwal S.K. , Guleria S. , Tiwari S.C.
Published: July 2008

Abstract: Panniculitis may result due to various etiologies. In post‐transplant immunosuppressed patients infection is the foremost cause of panniculitis. We present 2 cases of fungal panniculitis in renal transplant recipients. The first patient presented with non‐tender firm erythematous plaques on the left thigh. Biopsy showed panniculitis with cryptococci. Subsequent investigations revealed the presence of cryptococcal antigens in the blood, urine, and bronchoalveolar lavage fluid. There was no evidence of cryptococcal meningitis. The second patient complained of subcutaneous nodules on the trunk and right thigh. Biopsy of one of the nodules showed panniculitis with histoplasma. This patient had been treated earlier (inadequately) for disseminated histoplasmosis. Both the cases responded well to conventional amphotericin B therapy. Their renal functions remained stable.
Successful salvage treatment of disseminated cutaneous fusariosis with liposomal amphotericin B and terbinafine after allogeneic stem cell transplantation
Authors: Neuburger S. , Massenkeil G. , Seibold M. , Lutz C. , Tamm I. , Le Coutre P. , Graf B. , Doerken B. , Arnold R.
Published: July 2008

Abstract: Fusarium infections are associated with high mortality after allogeneic stem cell transplantation. We report on successful treatment of a disseminated cutaneous Fusarium proliferatum infection using liposomal amphotericin B and terbinafine. In vitro susceptibility tests of antifungal drugs suggest that terbinafine is a potent additional antifungal drug for disseminated cutaneous fusariosis.
A plateau potential mediated by the activation of extrasynaptic NMDA receptors in rat hippocampal CA1 pyramidal neurons
Authors: Suzuki Takayuki , Kodama Satoshi , Hoshino Chisato , Izumi Tomohisa , Miyakawa Hiroyoshi
Published: July 2008

Hippocampal pyramidal neurons express various extrasynaptic glutamate receptors. When glutamate spillover was facilitated by blocking glutamate uptake and fast synaptic transmission was blocked by antagonists of AMPA‐ and NMDA‐type glutamate receptors and an ionotropic GABA receptor blocker, repetitive synaptic stimulation evoked a persistent membrane depolarization that consisted of an early Ca2+‐independent component and a late Ca2+‐dependent component. The early component, which we refer to as a plateau potential, had a half‐width of 770 ± 160 ms and a steady peak level of −9.54 ± 3.50 mV. It was accompanied by an increase in membrane conductance, the I–V relationship of which showed a peak at −19.91 ± 2.18 mV and reversal of the current at −4.32 ± 2.13 mV, and was suppressed by high concentration of an NMDA receptor (NMDAR) antagonist d‐APV, or an NMDAR glycine‐binding site antagonist 5,7‐dCK. After blocking synaptically located NMDARs using MK801, the potential was still evoked synaptically when spillover was facilitated. A sustained depolarization was evoked by iontophoretic application of glutamate in the presence or absence of a glutamate uptake blocker. This potential was not affected by Na+ or Ca2+ channel blockers, but was suppressed by 5,7‐dCK, leaving an unspecified depolarizing potential. Iontophoresis of NMDA evoked a sustained depolarization that was blocked by a high concentration of d‐APV or 5,7‐dCK. The I–V relationship of the current during this potential was similar to that obtained during the synaptically induced plateau potentials. These results show that CA1 pyramidal neurons generate plateau potentials mediated most likely by activation of extrasynaptic NMDARs.
Suppression of visual cortical evoked responses following deprivation of pattern vision in adult mice
Authors: Siu Timothy L. , Morley John W.
Published: July 2008

The effect of visual loss on the adult neocortex can have significant impact on the success of a visual implant. Recent research has shown that the adult neocortex retains substantial plasticity following a disruption to its afferent input. The result of these changes may hamper the development of a visual prosthesis if visual sensation cannot be effectively restored by stimulation of the surviving elements of the visual pathway. In order to evaluate further the visual performance of the mammalian adult brain following visual loss, especially the dominant form of blindness in humans, namely loss of pattern vision, we examined the cortical evoked potential of adult mice following 7, 30 and 120 days of visual deprivation via bilateral eyelid suture. Cortical potentials were elicited with a flash visual stimulus or by electrical stimulation of the retina. We found that after 7 days deprivation there was a potentiation of the evoked response while at 30 and 120 days deprivation the visual evoked responses were significantly reduced. Increasing the visual stimulus intensity reduced the effects. The electrical evoked potential demonstrated a corresponding reduction in stimulus threshold at 7 days and a corresponding rise (40–50%) after 30 and 120 days. These findings suggest that the adult brain exhibited significant experience‐dependent modifications following visual loss, and the impact depended on the duration of deprivation. Such reduction in visual responsiveness, especially with electrical activation, will need to be taken into account in the development of a visual implant.
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

Brain‐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

It 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

Elevation 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

Letters 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

Theories 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

Proprioceptive 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

Glutamine 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.
LOOKING AT THE “POPULATION PROBLEM” THROUGH THE PRISM OF HETEROGENEITY: WELFARE AND POLICY ANALYSES*
Authors: Fan C. Simon , Stark Oded
Published: July 2008

Upon introducing heterogeneity and dynamics into a model of the demand for children, a problem of optimal population is defined and analyzed. It is shown that from the perspective of social welfare, better‐educated individuals produce too few children while less‐educated individuals produce too many children and all individuals invest too little in the education of their children. The impact of several policy tools geared at addressing the “population problem” is investigated, in particular how child allowances and other tax‐subsidy policies can be harnessed to enhance welfare, and how and why early childhood education programs can mitigate the “population problem.”
THE ECONOMIC RETURNS TO AN MBA*
Authors: Arcidiacono Peter , Cooley Jane , Hussey Andrew
Published: July 2008

Because MBA programs require work experience before admittance, prior wages can be exploited to disentangle the return to the degree from unobserved productivity. We find that controlling for individual fixed effects generally reduces the estimated returns to an MBA, particularly for those in top programs. However, for full‐time MBA students attending schools outside of the top‐25 the estimated returns are higher when we control for individual fixed effects. We show that there is some evidence that those who take the GMAT but do not obtain an MBA are stronger in dimensions such as workplace skills that are not easily measured.
INSTITUTIONAL TRAPS AND ECONOMIC GROWTH
Authors: Gradstein Mark
Published: July 2008

This article's point of departure is that low‐quality institutions, concentration of political power and material wealth, and underdevelopment are persistent over time. Its analytical model views an equal distribution of political power as a commitment device to enhance institutional quality, thereby promoting growth. The politically powerful coalition contemplates relinquishing of its power through democratization, weighing this advantageous consequence against the limit on own appropriative ability that it entails. The possibility of two developmental paths is exhibited: with concentration of political and economic power, low‐quality institutions, and slow growth; and a more equal distribution of political and economic resources, high‐quality institutions, and faster growth.
LOST IN STATE SPACE: ARE PREFERENCES STABLE?*
Authors: Andersen Steffen , Harrison Glenn W. , Lau Morten I. , Elisabet Rutström E.
Published: July 2008

We use field experiments to examine the temporal stability of risk preferences. Over a 17‐month period, we elicited risk preferences from subjects chosen to be representative of the adult Danish population. During this period we revisited many of these subjects and repeated a risk aversion elicitation task. We find some variation in risk attitudes over time, but we do not detect a general tendency for risk attitudes to increase or decrease over a 17‐month span. The results also suggest that risk preferences are state contingent with respect to personal finances.
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.
Treatment Strategies in Non‐ST‐Elevation Acute Coronary Syndromes in Patients Undergoing Percutaneous Coronary Intervention: An Evidence‐Based Review of Clinical Trial Results and Treatment Guidelines: Report on a Roundtable Discussion
Authors: COHEN MARC , HOEKSTRA JAMES , GIUGLIANO ROBERT , GRANGER CHRISTOPHER B. , GURBEL PAUL A. , HOLLANDER JUDD E. , MANOUKIAN STEVEN V. , POLLACK, JR CHARLES V. , SAUCEDO JORGE F.
Published: July 2008

With the availability of new data and the recent release of new European and US guidelines, contemporary care paradigms for the treatment of patients with non‐ST‐elevation acute coronary syndromes (NSTE ACS), including those undergoing percutaneous coronary intervention, are likely to undergo substantial changes. In recognition of this shifting landscape as well as the impact of new guidelines on care models for the treatment of patients with NSTE ACS, a roundtable was convened on October 25, 2007, to discuss the implications of these changes. The purpose of this review is to summarize the presentations and subsequent discussions from the roundtable, which examined the guidelines and evidence from a variety of perspectives, and to explore the best ways to incorporate new treatment paradigms into everyday clinical care. The multiple viewpoints expressed by the roundtable attendees illustrate the recognition that at this point, consensus has not been reached on the optimum algorithm for treatment of these patients. This article focuses on issues discussed during the roundtable from the perspective of the practicing cardiologist.
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.
Commentary on ‘UVB‐SPF’: the SPF labels of sunscreen products convey more than just UVB protection
Authors: Sayre Robert M. , Dowdy John C. , Lott Dennis L. , Marlowe Edward
Published: July 2008

The FDA recently published a proposed amendment of the Final Monograph for OTC Sunscreen Products. Among the proposals, FDA revised solar simulator performance specifications and additional labeling for sunscreen products. The maximum allowable labeled sun protection factor (SPF) was increased to SPF 50 while simultaneously requiring it to be called ‘UVB‐SPF’. UVB accounts for 80–91% of the erythemic effectiveness of the UV solar simulator specified in the amendment. Analysis of the specified solar simulator spectrum used to determine SPF indicates that if 100% of the UVB is blocked, it is mathematically impossible to achieve an SPF in excess of ∼11 without also blocking at least some UVA. Consequently significant UVA protection must be provided for sunscreen products to achieve SPFs of 15 and higher. At the maximum allowed SPF 50, where only 2% or less of the effective UV risk remains, the minimum reduction of UVA erythemal effectiveness must by definition be 78–90%. While mandating UVA protection criteria is doubtless important, especially as it relates to sunscreen photostability, there is no utility in, or basis for, the proposed ‘UVB‐SPF’ descriptor as existing high SPF labeling indicates both UVB and UVA protection.
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

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.