bluuebunny/crossref_metadata_2025_split huggingface dataset:
Astrocyte calcium waves: What they are and what they do
Authors: Scemes Eliana , Giaume Christian 
Published: September 2006

AbstractSeveral lines of evidence indicate that the elaborated calcium signals and the occurrence of calcium waves in astrocytes provide these cells with a specific form of excitability. The identification of the cellular and molecular steps involved in the triggering and transmission of Ca2+ waves between astrocytes resulted in the identification of two pathways mediating this form of intercellular communication. One of them involves the direct communication between the cytosols of two adjoining cells through gap junction channels, while the other depends upon the release of “gliotransmitters” that activates membrane receptors on neighboring cells. In this review we summarize evidence in favor of these two mechanisms of Ca2+ wave transmission and we discuss that they may not be mutually exclusive, but are likely to work in conjunction to coordinate the activity of a group of cells. To address a key question regarding the functional consequences following the passage of a Ca2+ wave, we list, in this review, some of the potential intracellular targets of these Ca2+ transients in astrocytes, and discuss the functional consequences of the activation of these targets for the interactions that astrocytes maintain with themselves and with other cellular partners, including those at the glial/vasculature interface and at perisynaptic sites where astrocytic processes tightly interact with neurons. © 2006 Wiley‐Liss, Inc.
Calcium signaling in Schwann cells at synaptic and extra‐synaptic sites: Active glial modulation of neuronal activity
Authors: Rousse Isabelle , Robitaille Richard 
Published: September 2006

AbstractGlial cells are widely dispersed in the central nervous system (CNS) as well as in the peripheral nervous system (PNS). In the PNS, perisynaptic Schwann cells (PSCs) are the glial cells associated with the pre‐ and postsynaptic elements of the neuromuscular junction (NMJ). They, as other glial cells of the CNS, respond to high‐frequency motor nerve stimulation with an increase in intracellular Ca2+. In addition to detecting and responding to neurotransmission, PSCs are involved in short‐term plasticity events where they depress neurotransmission through G‐protein‐dependent mechanisms and potentiate synaptic activity via Ca2+‐dependent mechanisms. In this review, we will discuss evidence that outlines the role of PSCs in short‐ and long‐term modulation of synaptic activity. We will also emphasize present functional similarities and differences in PSC activation at different NMJs. The importance of glial‐neural interactions along myelinating axons will also be discussed. © 2006 Wiley‐Liss, Inc.
P2X7 receptors: Properties and relevance to CNS function
Authors: Duan Shumin , Neary Joseph T. 
Published: September 2006

AbstractAmong seven members of P2X ionotropic receptors activated by extracellular ATP, the P2X7 subtype is unique in that it can function as a cation channel, a nonselective pore, or even a signaling complex coupled with multiple downstream components. Several roles of P2X7 receptors have been described in CNS cells in the past decade, including release of cytokines and transmitters, modulation of presynaptic transmitter release, and activation of multiple signaling pathways. The finding that P2X7 pores may directly mediate efflux of cytosolic glutamate, GABA, and ATP in glial cells is particularly interesting, as it provides a novel mechanism of glial transmitter release that may play important roles not only in physiological intercellular communication but also in pathological neural injury. © 2006 Wiley‐Liss, Inc.
Functional role of calcium signals for microglial function
Authors: Färber Katrin , Kettenmann Helmut 
Published: September 2006

AbstractIn this review we summarize mechanisms of Ca2+ signaling in microglial cells and the impact of Ca2+ signaling and Ca2+ levels on microglial function. So far, Ca2+ signaling has been only characterized in cultured microglia and thus these data refer rather to activated microglia as observed in pathology when compared with the resting form found under physiological conditions. Purinergic receptors are the most prominently expressed ligand‐gated Ca2+‐permeable channels in microglia and control several microglial functions such as cytokine release in a Ca2+‐dependent fashion. A large variety of metabotropic receptors are linked to Ca2+ release from intracellular stores. Depletion of these intracellular stores triggers a capacitative Ca2+ entry. While microglia are already in an activated state in culture, they can be further activated, for example, by exposure to bacterial endotoxin. This activation leads to a chronic increase of [Ca2+]i and this Ca2+ increase is a prerequisite for the release of nitric oxide and cytokines. Moreover, several factors (TNFα, IL‐1β, and IFN‐γ) regulate resting [Ca2+]i levels. © 2006 Wiley‐Liss, Inc.
Neurotransmitter‐mediated calcium signalling in oligodendrocyte physiology and pathology
Authors: Butt Arthur M. 
Published: September 2006

AbstractThe function of oligodendrocytes is to myelinate CNS axons. Oligodendrocytes and the axons they myelinate are functional units, and neurotransmitters released by axons can influence all stages of oligodendrocyte development via calcium dependent mechanisms. Some of the clearest functional evidence is for adenosine, ATP, and glutamate, which are released by electrically active axons and regulate the migration and proliferation of oligodendrocyte progenitor cells and their differentiation into myelinating oligodendrocytes. Glutamate and ATP, released by both axons and astrocytes, continue to mediate Ca2+ signaling in mature oligodendrocytes, acting via AMPA and NMDA glutamate receptors, and heterogeneous P2X and P2Y purinoceptors. Physiological signalling between axons, astrocytes, and oligodendrocytes is likely to play an important role in myelin maintenance throughout life. Significantly, ATP‐ and glutamate‐mediated Ca2+ signaling are also major components of oligodendrocyte and myelin damage in numerous pathologies, most notably ischemia, injury, periventricular leukomalacia, and multiple sclerosis. In addition, NG2‐expressing glia (synantocytes) in the adult CNS are highly reactive cells that respond rapidly to any CNS insult by a characteristic gliosis, and are able to regenerate oligodendrocytes and possibly neurons. Glutamate and ATP released by neurons and astrocytes evoke Ca2+ signaling in NG2‐glia (synantocytes), and it is proposed these regulate their differentiation capacity and response to injury. In summary, clear roles have been demonstrated for neurotransmitter‐mediated Ca2+ signaling in oligodendrocyte development and pathology. A key issue for future studies is to determine the physiological roles of neurotransmitters in mature oligodendrocytes and NG2‐glia (synantocytes). © 2006 Wiley‐Liss, Inc.
Functional connexin “hemichannels”: A critical appraisal
Authors: Spray David C. , Ye Zu‐Cheng , Ransom Bruce R. 
Published: September 2006

Abstract“Hemichannels” are defined as the halves of gap junction channels (also termed connexons) that are contributed by one cell; “hemichannels” are considered to be functional if they are open in nonjunctional membranes in the absence of pairing with partners from adjacent cells. Several recent reviews have summarized the blossoming literature regarding functional “hemichannels”, in some cases encyclopedically. However, most of these previous reviews have been written with the assumption that all data reporting “hemichannel” involvement really have studied phenomena in which connexons actually form the permeability or conductance pathway. In this review, we have taken a slightly different approach. We review the concept of “hemichannels”, summarize properties that might be expected of half gap junctions and evaluate the extent to which the properties of presumptive “hemichannels” match expectations. Then we consider functions attributed to hemichannels, provide an overview of other channel types that might fulfill similar roles and provide sets of criteria that might be applied to verify involvement of connexin hemichannels in cell and tissue function. One firm conclusion is reached. The study of hemichannels is technically challenging and fraught with opportunities for misinterpretation, so that future studies must apply rigorous standards for detection of hemichannel expression and function. At the same time there are reasons to expect surprises, including the possibility that some time honored techniques for studying gap junctions may prove unsuitable for detecting hemichannels. We advise hemichannel researchers to proceed with caution and an open mind. © 2006 Wiley‐Liss, Inc.
Validation of the Spanish version of the EURO‐D scale: an instrument for detecting depression in older people
Authors: Larraga Laura , Saz Pedro , Dewey Michael E. , Marcos Guillermo , Lobo Antonio 
Published: September 2006

AbstractObjectiveTo standardize the EURO‐D scale as a method for detecting depression in Spanish older people.MethodsIn a first phase, a sample of 1080 community older people was assessed with the GMS‐AGECAT by lay interviewers. In a second phase, all the probable cases and a similar number of randomly selected probable non‐cases were assessed using DSM‐III‐R diagnosis by psychiatrists. To test reliability, internal consistency with the Cronbach alpha coefficient and test–retest reliability (Kappa value) were obtained. Validity, sensitivity and specificity, predictive values, Receiver Operating Characteristic (ROC) curve, and Specific Likelihood Ratios (SSLR) were calculated.ResultsA high internal consistency was obtained in both phases of the study (α = 0.75; α = 0.79, respectively). Test–retest reliability was acceptable (weighted kappa = 0.60). For the prediction of DSM‐III‐R diagnosis validity coefficients (cut‐off point 3/4) were: sensitivity 91.8%, specificity 76.6% and area under the ROC curve 0.92 [95% Confidence Intervals (0.89–0.95)]. Illiteracy and cognitive difficulties had a small negative effect on the performance of the scale.ConclusionsThe EURO‐D scale is a reliable and valid instrument for detecting probable cases of depression in older people in Spain. Illiteracy and cognitive difficulties should be considered when interpreting the results. Copyright © 2006 John Wiley & Sons, Ltd.
A systematic review of intervention studies about anxiety in caregivers of people with dementia
Authors: Cooper Claudia , Balamurali T. B. S. , Selwood Amber , Livingston Gill 
Published: September 2006

AbstractBackgroundThere is considerable literature on managing depression, burden and psychological morbidity in caregivers of people with dementia (CG). Anxiety has been a relatively neglected outcome measure but may require specific interventions.ObjectiveTo synthesise evidence regarding interventions that reduce anxiety in CGs.MethodsTwenty‐four studies met our inclusion criteria. We rated the methodology of studies, and awarded grades of recommendation (GR) for each type of intervention according to Centre for Evidence Based Medicine guidelines, from A (highest level of evidence) to D.ResultsAnxiety level was the primary outcome measure in only one study and no studies were predicated on a power calculation for anxiety level. There was little evidence of efficacy for any intervention. The only RCT to report significantly reduced anxiety involved a CBT and relaxation‐based intervention specifically devised to treat anxiety, and there was preliminary evidence (no randomised controlled trials) that caregiver groups involving yoga and relaxation without CBT were effective. There was grade B evidence that behavioural management, exercise therapies and respite were ineffective.LimitationsMany interventions were heterogeneous, so there is some overlap between groups. Lack of evidence of efficacy is not evidence of lack of efficacy.ConclusionsCBT and other therapies developed primarily to target depression did not effectively treat anxiety. Good RCTs are needed to specifically target anxiety which might include relaxation techniques. Some of the interventions focussed on reducing contact with the care recipients but caregivers may want to cope with caring and preliminary evidence suggests strategies to help CGs manage caring demands may be more effective. Copyright © 2006 John Wiley & Sons, Ltd.
Specific symptomatic changes following donepezil treatment of Alzheimer's disease: a multi‐centre, primary care, open‐label study
Authors: Rockwood Kenneth , Black Sandra , Bedard Marc‐Andre , Tran Thang , Lussier Isabelle 
Published: September 2006

AbstractBackgroundStandard measurement scales used in anti‐dementia trials may not capture symptomatic changes recognized by clinicians and caregivers. We studied a symptom checklist, completed separately by caregivers and by clinicians, to identify patterns of change associated with donepezil treatment.MethodsIn a multi‐centre, 6‐month, open‐label study of 101 primary care patients, changes in a 19‐symptom checklist were assessed in relation to changes in standardized scales of cognition, activities of daily living, behavior, and caregiver burden.ResultsThree symptoms were reported in more than 80% of patients by both clinicians and caregivers: problems in remembering, (97%), temporal orientation (89%), and repetitiveness (85%). Five others overlapped on each of the clinician and caregiver ‘top ten’, including cognitive activation, spatial orientation, leisure, attention, and apathy. Clinicians reported that symptoms did not improve in 38 patients, whereas there was some improvement in 43, and improvement in most symptoms in 20. Caregivers reported that symptoms did not improve in 55 patients, whereas 27 and 19 patients showed some and most symptoms improving respectively. Patients with the greatest symptomatic improvement also improved most on the ADAS‐Cog and the other standardized measures, whereas no improvement (or decline) in each standardized measure was observed in people whose symptoms worsened or did not improve.ConclusionA symptom checklist allowed clinically meaningful profiles to be identified, but revealed different estimates of response between clinicians and caregivers. Both agreed that improved executive function was the most common response. A symptom checklist can help translate between standard measures and everyday practice. Copyright © 2006 John Wiley & Sons, Ltd.
A randomized, double‐blind, placebo‐controlled trial of donepezil hydrochloride (Aricept) for reducing the incidence of postoperative delirium after elective total hip replacement
Authors: Sampson Elizabeth L. , Raven Peter R. , Ndhlovu Patricia N. , Vallance Aaron , Garlick Nicholas , Watts Julie , Blanchard Martin R. , Bruce Angela , Blizard Robert , Ritchie Craig W. 
Published: September 2006

AbstractObjectivesThis was a pilot, phase 2a study to assess methodological feasibility and the safety and efficacy of donepezil in preventing postoperative delirium after elective total hip replacement surgery in older people without pre‐existing dementia. The hypothesis was that donepezil would reduce the incidence of postoperative delirium.MethodsA double blind, placebo controlled, parallel group randomized trial was undertaken. Patients were block randomized pre‐operatively to receive placebo or donepezil 5 mg immediately following surgery and every 24 h thereafter for a further three days. The main outcome was the incidence of delirium (using the Delirium Symptom Interview). The secondary outcome was length of hospital stay.ResultsThirty‐three patients (mean age 67 years; 17 males, 16 females) completed the study (19 donepezil, 14 placebo). Donepezil was well tolerated with no serious adverse events. Postoperative delirium occurred in 21.2% of subjects. Donepezil did not significantly reduce the incidence of delirium. The unadjusted risk ratio (donepezil vs placebo) for delirium was 0.29 (95% CI = 0.06,1.30) (χ2[1] = 3.06; p = 0.08). Mean length of hospital stay was 9.9 days for the donepezil group vs 12.1 days in the placebo group; difference in means = −2.2 days (95% CI = −0.39,4.78) (t[31] = 1.73: p = 0.09).ConclusionsThe experimental paradigm was feasible and acceptable. Donepezil did not significantly reduce the incidence of delirium or length of hospital stay, however for both outcomes there was a consistent trend suggesting possible benefit. The sample size required for a definitive trial (99% power, alpha 0.05) would be 95 subjects per arm. Copyright © 2006 John Wiley & Sons, Ltd.
Is there a causal link between currency and debt crises?
Authors: Dreher Axel , Herz Bernhard , Karb Volker 
Published: September 2006

AbstractThough currency and debt crises quite often occur simultaneously, the links between these two types of crises are not well understood. We review how currency and debt crises could be related due to common causes, contagion effects from one crisis to the other, and complementary budget financing aspects. In an empirical analysis based on a panel of 80 countries over the period 1975–2000, we first investigate the determinants of each crisis separately. Then we estimate links between both crises employing instrumental variables techniques. We find that, while there is a negative lagged influence of currency crises on debt crises, currency crises significantly increase the risk of contemporaneous debt crises and vice versa. Copyright © 2006 John Wiley & Sons, Ltd.
Extended evidence on the use of technical analysis in foreign exchange
Authors: Gehrig Thomas , Menkhoff Lukas 
Published: September 2006

AbstractThis work extends earlier survey studies on the use of technical analysis by considering flow analysis as a third form of information production. Moreover, the survey covers FX dealers and also the rising fund managers. Technical analysis has gained importance over time and is now the most equally spread kind of analysis. It has by far the greatest importance in FX dealing and is second in fund management. Charts are used for shorter‐term forecasting horizons while flows dominate at the shortest‐term and fundamentals at longer horizons. Preferred users of each kind of analysis exhibit different views about market frictions. Copyright © 2006 John Wiley & Sons, Ltd.
MS‐KIF18A, a kinesin, is associated with estrogen receptor
Authors: Luboshits G. , Benayahu D. 
Published: September 2006

AbstractThe study of MS‐KIF18A kinesin protein is focused on its cellular distribution and association with a cargo protein. Indirect immunofluorescence (IF) analyzed the intracellular distribution of endogenous MS‐KIF18A and the transfected enhanced green fluorescence protein (eGFP)‐MS‐KIF18A in osteogenic cells. In both cases, the proteins were localized at the plasma membrane, cytosol, and nucleus. Bioinformatics analysis suggested interactions between MS‐KIF18A and estrogen receptor (ERα) which were further elucidated by immunoprecipitation (IP). We identified interaction between endogenous MS‐KIF18A with 66 and 46 kDa isoforms of ERα in MBA‐15 cells. Moreover, MS‐KIF18A and 66 kDa ERα complex has been demonstrated between ectopically expressed proteins in COS‐7 cells. We have shown that anti‐MS‐KIF18A antibody immunoprecipitated the ERα and pERK in cells challenged with 17β‐estrogen (17β‐E2). The hormone activation induced mitogen‐activated protein kinases (MAPK) pathway and increased p‐ERK. The activation was interfered when cells were pre‐treated with either ICI‐182,780 or MAPK inhibitor PD98059 prior the challenge with 17β‐E2 that resulted in a decrease in association between MS‐KIF18A and p‐ERK1/2. The obtained results suggest a role for the proteins in a non‐genomic response of MBA‐15 cells challenged with 17β‐E2. This study presents a novel interaction between MS‐KIF18A and ER that may have important physiological and pharmacological implications for estrogen action in various cells. J. Cell. Biochem. 100: 693–702, 2007. © 2006 Wiley‐Liss, Inc.
Matrix regulation of skeletal cell apoptosis III: Mechanism of ion pair‐induced apoptosis
Authors: Saunders Ray , Szymczyk Krysia H. , Shapiro Irving M. , Adams Christopher S. 
Published: September 2006

AbstractOur previous work has demonstrated that while the Ca2+ and Pi ions acting in concert function as a potent osteoblast apoptogen, the underlying mechanisms by which it activates cell death is not known. We hypothesize that the ion pair causes release of Ca2+ from intracellular stores ([Ca2+]i); the increase in intracellular calcium prompts the mitochondria to uptake more calcium. This accumulation of calcium eventually results in the loss of mitochondrial membrane potential (MMP) and, subsequently, apoptosis. To test this hypothesis, we evaluated apoptosome formation in MC3T3‐E1 osteoblast‐like cells treated with the ion pair. Western blot analysis indicated migration of cytochrome‐c and Smac/DIABLO from mitochondria to the cytoplasm. Inhibition of either the electron transfer chain (with antimycin a and rotenone), or the activation of a MMP transition (with bongkrekic acid) inhibited apoptosis in a dose‐dependent manner. Pre‐treating osteoblasts with ruthenium red, a Ca2+ uniporter inhibitor of both mitochondria and the endoplasmic reticulum (ER), also completely abolished Ca2+.Pi‐induced apoptosis. Moreover, we showed that an increase in [Ca2+]i preceded the increase in MMP over the first 45 min of treatment; a mitochondrial membrane permeability transition was evident at 75 min. To determine the role of ER, Ca2+ stores in the generation of the apoptotic signal by the ion pair, cells were treated with several inhibitors. Apoptosis was inhibited when cells were treated with dantrolene, an inhibitor of ER ryanodine receptors, and 2‐aminodiphenylborate, an IP3 Ca2+ channel inhibitor, but not cyclopiazonic acid, an ER Ca2‐ATPase inhibitor. Together, these data demonstrate that Ca2+ Pi‐induced osteoblast apoptosis is characterized by the generation of an apoptosome and that Ca2+ release from ER stores may promote ion pair‐dependent cell death. J. Cell. Biochem. 100: 703–715, 2007. © 2006 Wiley‐Liss, Inc.
X‐ray fluorescence microprobe imaging in biology and medicine
Authors: Paunesku Tatjana , Vogt Stefan , Maser Jörg , Lai Barry , Woloschak Gayle 
Published: September 2006

AbstractCharacteristic X‐ray fluorescence is a technique that can be used to establish elemental concentrations for a large number of different chemical elements simultaneously in different locations in cell and tissue samples. Exposing the samples to an X‐ray beam is the basis of X‐ray fluorescence microscopy (XFM). This technique provides the excellent trace element sensitivity; and, due to the large penetration depth of hard X‐rays, an opportunity to image whole cells and quantify elements on a per cell basis. Moreover, because specimens prepared for XFM do not require sectioning, they can be investigated close to their natural, hydrated state with cryogenic approaches. Until several years ago, XFM was not widely available to bio‐medical communities, and rarely offered resolution better then several microns. This has changed drastically with the development of third‐generation synchrotrons. Recent examples of elemental imaging of cells and tissues show the maturation of XFM imaging technique into an elegant and informative way to gain insight into cellular processes. Future developments of XFM—building of new XFM facilities with higher resolution, higher sensitivity or higher throughput will further advance studies of native elemental makeup of cells and provide the biological community including the budding area of bionanotechnology with a tool perfectly suited to monitor the distribution of metals including nanovectors and measure the results of interactions between the nanovectors and living cells and tissues. J. Cell. Biochem. 99: 1489–1502, 2006. © 2006 Wiley‐Liss, Inc.