bluuebunny/crossref_metadata_2025 huggingface dataset:
High brightness picosecond electron gun
Authors: Merano M. , Collin S. , Renucci P. , Gatri M. , Sonderegger S. , Crottini A. , Ganière J. D. , Deveaud B.
Published: August 2005

We have developed a high brightness picosecond electron gun. We have used it to replace the thermionic electron gun of a commercial scanning electron microscope (SEM) in order to perform time-resolved cathodoluminescence experiments. Picosecond electron pulses are produced, at a repetition rate of 80.7MHz, by femtosecond mode-locked laser pulses focused on a metal photocathode. This system has a normalized axial brightness of 93A∕cm2srkV, allowing for a spatial resolution of 50nm in the secondary electron imaging mode of the SEM. The temporal width of the electron pulse is 12ps.
Enhancement of terahertz radiation from photoconductors by elliptically focused excitation
Authors: Kim Dae Sin , Citrin D. S.
Published: August 2005

Based on simulations from a detailed Monte Carlo Poisson solver, we show that the effects of photoinduced screening of the bias field as a function of optical spot shape for ultrafast excitation of photoconductors to generate terahertz transients leads to alteration of the temporal shape of the terahertz transients related to the photoexcited carrier drift velocity. The results of the simulations demonstrate that given the same photoexcited carrier density, a line focus parallel to the direction of the bias field suppresses saturation at high optical fluence due to space-charge screening and enhances the peak terahertz power in the time domain.
Alternative splicing of the Vupur3 transcript in cowpea produces multiple mRNA species with a single protein product that is present in both plastids and mitochondria
Authors: Bussell John D. , Hall Doug J. , Mann Anthea J. , Goggin Danica E. , Atkins Craig A. , Smith Penelope M. C.
Published: August 2005

A heterogeneous population of cDNAs (designated Vupur3) encoding phosphoribosylglycinamide formyltransferase (GART; EC 2.1.2.2) was isolated from a cowpea (Vigna unguiculata L. Walp.) nodule library. Three classes of cDNA with the same ORF, but differing in their 3′-UTRs, were identified. Southern analysis and sequencing of genomic DNA confirmed that these differences result from alternative splicing of the primary transcript of a single Vupur3 gene. Alternative splicing does not appear to play a role in the production of soybean (Glycine max Merrill.) pur3 transcripts. The presence of the protein product of the Vupur3 gene, GART, in plastids and mitochondria was confirmed by immunoblotting with antibodies raised against the recombinant protein. The antibodies recognised two proteins with apparent molecular masses of 27 and 27.5 kDa in both mitochondria and plastids. All Vupur3 transcripts have two in-frame start codons that are active in wheatgerm in vitro transcription / translation experiments suggesting a mechanism by which the gene product could be targeted to two organelles. Like other genes encoding enzymes for purine synthesis, Vupur3 is expressed in nodules before nitrogen fixation begins but in contrast to these genes its expression does not increase markedly after nitrogen fixation begins.
A lifecycle model of the scientific communication process
Authors: Björk Bo‐Christer
Published: August 2005

A formal model of the scientific communication process is presented using the IDEF0 notation. The model provides a roadmap for policy discussions and further research. In comparison to earlier models it is more detailed and hierarchical, and includes more modelling constructs. It includes the whole communication value chain, from initial research to the assimilation of research results to everyday practice. Although the model treats both informal and formal communication, as well as the publishing of data, its focus is on modelling the publishing and indexing of traditional peer‐reviewed journal articles, and finding and retrieving them. New developments enabled by the Internet, such as open access journals and e‐print repositories, are also included.
Advantages of university journals in China
Authors: Li Li
Published: August 2005

Traditional academic publishing is facing the ‘scholarly communication crisis’. University journals in China have special advantages in such circumstances and have the potential for developing strongly. Such journals not only have the academic achievements of their university as their base, but also get financial and administrative support from them. These journals play important roles in the cultivation of graduate students and teachers and can be regarded as the ‘shop windows’ of their university. University journals can now promote their accessibility and become more influential.
Evidence of age-dependent genetic influences on plasma total cholesterol
Authors: Middelberg Rita , Heath Andrew C. , Martin Nicholas G. , Whitfield John B.
Published: August 2005

Background Causes of variation in cardiovascular risk factors include biological variation within individuals, and more permanent differences between individuals, which are at least partly genetic in origin. We have compared the magnitude of genetic and non-genetic factors within and across occasions through repeated measures of plasma cholesterol in twin subjects, and have also determined how far the same genes affect cholesterol levels at different ages.

Methods Data on plasma total cholesterol were extracted for 208 twin pairs who had provided blood on up to six occasions across a period of 17 years. They were aged 18–30 years at the time of first study and 30–47 at the time of the last. Multivariate models of variation due to genetic, shared environmental and unique environmental factors were fitted to the multi-occasion data and the proportions of variation due to these factors were estimated.

Results One genetic factor influenced plasma cholesterol on all occasions and a second genetic factor only influenced cholesterol results on the fifth and sixth occasions 10–17 years after the first. Environmental factors did not have significant long-term effects.

Conclusions We conclude that individuals’ long-term mean plasma cholesterol values are strongly genetically determined, but that some of these genes are age-specific in their effects.
Gender differences in the presentation and management of acute coronary syndromes: a national sample of 1365 admissions
Authors: Doyle Frank , Harpe Davida De La , McGee Hannah , Shelley Emer , Conroy Ronán
Published: August 2005

Background Gender differences in presentation and management of acute coronary syndromes (ACS) are well established internationally. This study investigated differences in a national Irish sample.

Design Cross-sectional survey.

Methods All centres ( n = 39) admitting cardiac patients to intensive/coronary care provided information on 25 consecutive acute myocardial infarction patients and other ACS patients admitted concurrently ( n = 1365 episodes). Patient data was analyzed in terms of those with prior ACS/revascularization, and those without.

Results Men with prior established ACS/revascularization were twice as likely to have received revascularization procedures (coronary artery bypass graft or percutaneous coronary intervention) prior to admission when controlling for age, total cholesterol and insurance status [odds ratio (OR) 1.97, 95% confidence interval (CI) 1.18–3.29, P=0.011]. No gender differences were seen in acute-phase reperfusion (OR 0.96, 95% CI 0.76–1.24, P>0.05) or antiplatelet therapy (OR 0.99, 95% CI 0.69–1.41, P>0.05). For patients with prior ACS/revascularization, men were twice as likely to receive statins on discharge after adjustment for age and total cholesterol (OR 1.94, 95% CI 1.02–3.71, P=0.045).

Conclusions Women were treated differently to men. Fewer women with a positive history of ACS received revascularization prior to current admission and fewer women were prescribed lipid-lowering medications on discharge. Acute phase hospital treatment was not gender determined. These findings have implications for secondary prevention in Ireland.
The distressed (type D) personality is independently associated with impaired health status and increased depressive symptoms in chronic heart failure
Authors: Schiffer Angélique A. , Pedersen Susanne S. , Widdershoven Jos W. , Hendriks Eric H. , Winter Jobst B. , Denollet Johan
Published: August 2005

Background Chronic heart failure (CHF) is a serious condition that is associated with impaired health status and a high prevalence of depressive symptoms. To date, little is known about the determinants of health status and depressive symptoms in CHF. Therefore, the aim of this study was to assess whether Type D personality is associated with impaired health status and increased depressive symptoms in heart failure patients, independent of disease characteristics.

Methods Eighty-four patients (63 men and 21 women, mean age=65.9±12.1 years) with systolic CHF completed four questionnaires to assess Type D personality (14-item Type D Personality Scale [DS14]), health status (Minnesota Living with Heart Failure Questionnaire [MLWHFQ]), depressive symptoms (Center for Epidemiological Studies Depression Scale [CES-D]) and mood status (Global Mood Scale [GMS]) when visiting an outpatient heart failure clinic. Information on clinical variables was obtained from patients’ medical records.

Results Type D patients were more likely to experience impairment in health status (18/38=47%) as compared to non-Type Ds (11/46=24%), P=0.027. They also more often reported symptoms of depression; namely 18 of 38=47% versus 6 of 46=13%, P=0.001. When controlling for severity and etiology of CHF, age and gender, Type D remained a significant associate of impaired health status [odds ratio (OR) 3.0, 95% confidence interval (CI) 1.12–7.78] and depressive symptoms (OR 6.3, 95% CI 2.08–19.12).

Conclusions Type D was associated with impaired health status and increased depressive symptoms in CHF patients. These preliminary findings demonstrate the value of including personality factors in CHF research.
Cell lysis directed by σ E in early stationary phase and effect of induction of the rpoE gene on global gene expression in Escherichia coli
Authors: Kabir Md. Shahinur , Yamashita Daisuke , Koyama Satoshi , Oshima Taku , Kurokawa Ken , Maeda Maki , Tsunedomi Ryouichi , Murata Masayuki , Wada Chieko , Mori Hirotada , Yamada Mamoru
Published: August 2005

It has been shown thatEscherichia colicells with increased expression of therpoEgene encodingσEexhibit enhanced cell lysis in early stationary phase. Further analysis of the lysis phenomenon was performed using a transient expression system of therpoEgene and by DNA microarray. The former analysis revealed aσE-directed cell lysis, specific for early stationary phase but not for the exponential phase. The microarray analysis with RNAs from exponential and early stationary phase cells revealed that a large number of genes were up- or down-regulated when therpoEgene was induced, and that several genes were induced in a phase-specific manner. The upregulated genes include many previously identifiedσEregulon genes, suggesting that a large number of genes are under the control ofσEin this organism. These genes are involved in various cellular activities, including the cell envelope, cellular processes, regulatory functions, transport and translation. Genes that are presumably related to phase-specific cell lysis inE. coliare discussed.
Characterization of a regulatory gene essential for the production of the angucycline-like polyketide antibiotic auricin in Streptomyces aureofaciens CCM 3239
Authors: Novakova Renata , Homerova Dagmar , Feckova Lubomira , Kormanec Jan
Published: August 2005

A gene,aur1P, encoding a protein similar to the response regulators of bacterial two-component signal transduction systems, was identified upstream of theaur1polyketide gene cluster involved in biosynthesis of the angucycline-like antibiotic auricin inStreptomyces aureofaciensCCM 3239. Expression of the gene was directed by a single promoter,aur1Pp, which was transcribed at low levels during the exponential phase and induced just before the stationary phase. A divergently transcribed gene,aur1R, has been identified upstream ofaur1P, encoding a protein homologous to transcriptional repressors of the TetR family. Theaur1Pgene was disrupted in theS. aureofaciensCCM 3239 chromosome by homologous recombination. The mutation in theaur1Pgene had no effect on growth and differentiation. However, biochromatographic analysis of culture extracts from theS. aureofaciens aur1P-disrupted strain revealed that auricin was not produced in the mutant. This indicated thataur1Pis essential for auricin production. Transcription from the previously characterizedaur1Appromoter, directing expression of the first gene,aur1A, in the auricin gene cluster, was dramatically decreased in theS. aureofaciensCCM 3239aur1Pmutant strain. Moreover, the Aur1P protein, overproduced inEscherichia coli, was shown to bind specifically upstream of theaur1Appromoter region. The results indicated that the Aur1P regulator activates expression of the auricin biosynthesis genes.
Open access, open source and e‐theses: the development of the Edinburgh Research Archive
Authors: Jones Richard , Andrew Theo
Published: August 2005

Purpose

To examine how the synergy of open access and open source have been used at Edinburgh University Library to design and implement an e‐thesis service, and to offer a comfortable theoretical framework to aid others.

Design/methodology/approach

The concepts of open access and open source are introduced and compared to show the conceptual relationship between them and the natural partnering of these approaches to information freedom. The development of the open access repository (Edinburgh Research Archive, ERA) and the related open source software (Tapir for DSpace) are then examined as an opportunity for other implementers and developers to gain insight, both technical and non‐technical.

Findings

That open access and open source are a natural and forward looking way to develop e‐theses and other research material repositories. The discussion of developing open source and the brief study of the creation of ERA show us that this approach is both warranted and useful.

Research limitations/implications

It shows how institutions can leverage open source technology successfully, and further consideration must be given to this development methodology.

Practical implications

Software and documentation outcomes available for the community have been produced should aid the further research in this area and provide a good starting point for institutions.

Originality/value

We discuss for the first time both the theoretical aspects and the practical considerations surrounding an e‐theses archive which is of value to any group of information professionals considering similar activities.
National library web sites in Europe: an analysis
Authors: Pisanski Jan , Žumer Maja
Published: August 2005

Purpose

An overview of the contents and design of web pages of the European national libraries.

Design/methodology/approach

The theoretical part features the concepts, problems and guidelines for design related to web sites of national libraries. Based on this knowledge, an expert evaluation was carried out, including a brief overview of all homepages of European national libraries, accessible from the Gabriel server in 2004, as well as a much broader survey of web sites of nine national libraries (Austria, Bosnia‐Herzegovina, Croatia, Denmark, Italy (Florence), Poland, Slovenia, Spain, UK).

Findings

The survey shows that European national library web sites do, in fact, have a common core of content and, in large part, follow the design guidelines, but there are still some deviations from the recommendations. National libraries of the economically better developed countries have better web sites in terms of the following guidelines, whereas national libraries of the Eastern and Southern European countries fare slightly worse.

Originality/value

This paper identifies the sites that set the example for other libraries to follow. Also, a list of actual shortcomings of the existing web sites is presented.
Outsourcing of human resource management services in Greece
Authors: Galanaki Eleanna , Papalexandris Nancy
Published: August 2005

Purpose

Outsourcing is gaining considerable popularity in the field of business services and management. The purpose of this paper is to illustrate the practice of outsourcing human resource management (HRM) functions, such as training, staffing, rewards and restructuring, in Greece.

Design/methodology/approach

The analysis draws upon both primary and secondary data. The findings of the 1999 CRANET survey and a study on the companies that offer HRM services in Greece are used to set the frame of analysis. A series of in‐depth interviews with HR managers and senior HRM consultants are used to support the quantitative data.

Findings

The analysis suggests that the Greek market of HRM services is still at an initial stage of development, with limited credibility, while the customers lack the experience of managing outsourcing relations and are reluctant to establish a partnership‐ type HRM outsourcing agreement. Considerable differences are identified between the Greek market for HRM services and those of more developed markets.

Originality/value

The description of the Greek market of HRM services can be useful to vendors and users of HRM services, as well as researchers dealing with outsourcing in small markets.
Roof construction defects of medium‐rise buildings in sub‐tropical climates
Authors: Lo Y.T. , Leung W.M. , Cui H.Z.
Published: August 2005

Purpose

Cracks in the roof parapet wall and damage to the waterproofing membrane are the common defects of roof construction that require frequent maintenance. This paper seeks to review the common defects of roof construction of medium‐rise buildings in sub‐tropical climates.

Design/methodology/approach

The research reported was carried out by the survey and analysis of 20 case study buildings. The modes of rooftop parapet wall dislocation are studied and the effects of thermal expansion and end conditions of the parapet wall on the damage to the waterproofing membrane are analysed.

Findings

Parapet wall dislocation failure is dependent on whether the ends are hinged or fixed. Failure usually leads to tearing of the waterproofing membrane.

Practical implications

Modification to the roof parapet wall design and to the selection of construction materials is suggested.

Originality/value

The modes of failure and proposed modification will be of interest to designers and those responsible for the maintenance of flat‐roofed buildings in sub‐tropical climates.
The search for a conceptual framework
Authors: Page Michael
Published: August 2005

Purpose

The paper is an exercise in “metaphoric defamiliarisation”. The metaphor of the search for a conceptual framework as “quest” is unpacked and an alternative, based on Lewis Carroll's The Hunting of the Snark, is proposed in its place.

Design/methodology/approach

Many points of correspondence between Carroll's unlikely expedition and the work of standard setting bodies are noted and developed. The possibility that a conceptual framework might turn out to be a “Boojum” is examined.

Findings

Noting that timing precludes the possibility that The Hunting of the Snark is an allegory of accounting standard setting, a possible social explanation drawing on Cornford's Microcosmographia Academica is proposed.

Originality/value

Examines the use of the quest metaphor and what it tells us about standard setters' approaches. An alternative metaphor is proposed as being more appropriate and, by contrasting the two, the content of the first is thrown into sharper relief.
An ontological representation of learning objects and learning designs as codified knowledge
Authors: Sánchez‐Alonso Salvador , Frosch‐Wilke Dirk
Published: August 2005

Purpose

The aim of this paper is discussing about the similarities between the life cycle of knowledge management and the processes in which learning objects are created, evaluated and used.

Design/methodology/approach

The paper describes LO and learning designs and depicts their integration into the knowledge life cycle (KLC) of the KMCI, showing the main ontological definitions required to represent the proposed integration, putting them into relation with previous research in the topic.

Findings

The main points in that the “learning object” concept can be connected to existing KLC models in order to provide a more comprehensive framework for reuse‐oriented e‐learning and knowledge management.

Originality/value

The paper describes how to integrate learning‐oriented artefacts as part of the organizational context, in particular, as part of the knowledge life cycle (KLC). It also depicts the integration of a reuse‐oriented e‐learning framework into the KLC of the KMCI in the form of ontological definitions.
Implementing performance management in England's primary schools
Authors: Brown Andrew
Published: August 2005

Purpose

To provide an overview of the various ways in which performance management is being implemented in England's primary schools.

Design/methodology/approach

A combination of documentary analysis, participant observation and audio‐taped interviews with primary school headteachers, deputy headteachers, teachers and school governors.

Findings

Information is provided on the following aspects of performance management in primary schools: the meaning and purposes of performance management in primary schools; education and training for performance management; formulation and content of performance management objectives; measuring the performance of heads and teachers; the effects of performance management on teachers' professional development; and perceptions concerning the appropriateness and reality of performance related pay.

Research limitations/implications

Owing to the relatively small number of research participants, the findings might not be entirely representative of the opinions and experiences of primary school headteachers, teachers and governors throughout England as a whole. The value of introducing performance management into primary schools remains an area for further research.

Practical implications

A useful paper both for managers who are reviewing the operational effectiveness of performance management within their own schools, as well as for organisations that are considering the introduction of performance management into their school system.

Originality/value

This paper might be of particular value to national governments and smaller organisations that wish to consider how to evaluate the effectiveness of the various options before introducing a system of performance management into their whole primary school network.
Perversity in public service performance measurement
Authors: Pidd M.
Published: August 2005

Purpose

To discuss some of the reasons why performance measurement systems in public services can lead to dysfunctional consequences even when people operate with the best of intentions.

Design/methodology/approach

The paper draws together literature from the UK public sector, from writers in performance measurement and from cultural insights in anthropology to understand why some of these perverse effects occur.

Findings

Though many reasons are cited for public service performance measurement regimes, it is clear that control aspects dominate the others. This, when allied to an unthinking use of cybernetic metaphors, is what can lead to dysfunctionality.

Originality/value

The paper should appeal to those who wish to improve the performance of performance measurement systems in public services and to those who wish to understand why things can go wrong.
Cesarean delivery and cow milk allergy/intolerance
Authors: Eggesbø M. , Botten G. , Stigum H. , Samuelsen S. O. , Brunekreef B. , Magnus P.
Published: August 2005

The present study provides support for a positive association between cesarean delivery and persistent cow milk allergy/cow's milk intolerance. Correspondingly, a negative association was seen between cesarean delivery and early outgrown cow milk allergy/intolerance. A possible explanation is that cesarean delivery, rather than increasing the overall risk of food allergy, increases the risk of persistency of disease among food allergic children.
Nurses’ job dissatisfaction and turnover intention: Methodological myths and an alternative approach
Authors: Takase Miyuki , Maude Phillip , Manias Elizabeth
Published: August 2005

Abstract  Job dissatisfaction and turnover are recurring themes in nursing. The current international nursing shortage has resulted in increased interest in investigating the causes of nurses’ job dissatisfaction and turnover, and in developing countermeasures to address these issues. This paper involves a review of quantitative nursing studies, which investigated the causes of nurses’ job dissatisfaction and turnover intention, and identifies commonly held myths that may inhibit more nurse‐centered strategies from being developed. These myths are based on an assumption that a nurse‐environment relationship is a one‐way interaction in which nurses passively respond to their environment. The paper introduces the person‐environment fit theory as an alternative framework, which challenges the assumption by suggesting it is the relationship between person and environment, rather than environmental characteristics alone, that affects nurses’ occupational behavior. This theory enables nurse researchers to develop a more mutual approach involving the nurse and environment.
Effects of Seprafilm on peritoneal fibrinolytic system
Authors: Tarhan Omer Ridvan , Eroglu Aydan , Cetin Recep , Ynce Ayper , Bulbul Mahmut , Altuntas Yrfan
Published: August 2005

Background:  There is a high incidence of adhesions after ventral hernia repair with polypropylene mesh. The purpose of the present study was to evaluate the efficacy of Seprafilm in the prevention of adhesion formation and effect on peritoneal fibrinolytic activity.

Methods:  An incisional hernia model was created in rats. In the experimental group Seprafilm was placed between polypropylene mesh and abdominal organs. On the 14th day adhesions were evaluated and tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), plasminogen activator inhibitor (PAI) type 1 and 2 were measured in peritoneal biopsy specimens.

Results:  Adhesions were significantly reduced in the Seprafilm group (P = 0.002). Nevertheless, there were no difference between the two groups in levels of tPA, PAI‐1 and PAI‐2. However, the levels of uPA were significantly decreased in the Seprafilm group.

Conclusions:  The adhesion preventive effect of Seprafilm is not directly related in peritoneal fibrinolytic activity. Instead, the physical properties (barrier, hydroflotation and sliconizing effect) of the membrane are primarily responsible for adhesion prevention.
Sleep Disturbance in Children with Rett Syndrome: A Qualitative Investigation of the Parental Experience
Authors: McDougall Allyson , Kerr Alison M. , Espie Colin A.
Published: August 2005

Background  Sleep problems in children with intellectual disability can be precipitated and maintained by intrinsic and external factors. The present study comprised a qualitative investigation of the experiences of parents of children with Rett syndrome, a neurodevelopmental disorder where sleep disturbance is common.

Method  Audio‐taped interviews were conducted with nine families. Transcripts were analysed by theoretical coding to develop categories and themes, facilitated by the computer package qsr nud*ist.

Results  Themes and sub‐themes were identified in the areas of (1) parents’ beliefs about sleep problems, (2) coping with sleep problems, and (3) emotions, and an interactional model of the three systems was suggested.

Conclusions  A proposed interactional model of parental beliefs, coping and emotions in relation to sleep disturbance in children with Rett syndrome is consistent with existing theoretical models. Further research is required to test out the applicability of this conceptual framework to parents of children with other aetiologies of intellectual disability.
Metabolic Abnormalities and New‐Onset Seizures in Human Immunodeficiency Virus‐Seropositive Patients
Authors: Van Paesschen Wim , Bodian Carol , Maker Howard
Published: August 2005

Summary Seizures are a recognized complication of human immunodeficiency virus (H1V)‐type‐1 infection. CNS disease processes in these patients include encephalitis, focal brain lesions, and meningitis. Metabolic causes of seizures have received little attention. In a retrospective study, we selected 68 HIV‐seropositive patients with new‐onset seizures and information available for specified metabolic factors on the day of the first seizure. We sought an association of metabolic abnormalities with convulsive status epilepticus (CSE), which was the initial seizure in 12 patients, predominantly intravenous (i.v.) drug users. HIV‐seropositive patients with new‐onset seizures and hypomagnesemia or renal failure appeared to be at increased risk for CSE. All HIVseropositive patients with new‐onset seizures should undergo metabolic screening including renal function and serum magnesium levels.
Effects of Differing Dosages of Vigabatrin (Sabril) on Cognitive Abilities and Quality of Life in Epilepsy
Authors: Dodrill Carl B. , Arnett John L. , Sommerville Kenneth W. , Sussman Neil M.
Published: August 2005

Summary Vigabatrin (VGB) prevents seizures by irreversible inhibition of γ‐aminobutyric acid (GABA) transaminase and a resulting increase in GABA levels. We evaluated the cognitive and quality‐of‐life (QOL) effects of VGB in a double‐blinded, add‐on, placebo‐controlled, parallel group dose‐response study of patients with focal epilepsy whose complex partial seizures (CPS) were difficult to control. In a single investigation, patients were randomly assigned to placebo (n = 40), 1 g VGB (n = 36), 3 g VGB (n = 38), or 6 g VGB (n = 32), treated for 12 weeks after a 6‐week dose escalation period, and tested at the end of the baseline period and at the end of the treatment period with eight cognitive measures and three tests of mood and adjustment. The patient groups were highly similar at study entry. Results at the end of the study showed substantial relief from seizures. The Digit Cancellation Test showed decreases in performance with increasing doses of VGB. Performance on no other test showed any decrement with increasing dosage. Relief from seizures was not associated with changes on the psychological tests. VGB is a useful antiepileptic drug (AED) that has little impact on tests of either cognitive abilities or QOL, even at a high dose.
Diffuse Spike‐Wave Status of 9‐Year Duration Without Behavioral Change or Intellectual Decline
Authors: Gökyiǧit Aysen , Çalişkan Ahmet
Published: August 2005

Summary Continuous, generalized 2.5 to 3.5‐Hz spikewave (SW) discharges were evident in an EEG performed 13 h after a first seizure associated with a viral illness, in an 8‐year‐old girl. On eye opening, the EEG abnormality was suppressed and replaced by delta activity and brief spike‐wave paroxysms. No alteration in consciousness and seizures or behavioral abnormalities accompanied the EEG findings. Based on the EEG, she was diagnosed as having “diffuse electrical status,” the rare EEG phenomenon that occurs during wakefulness without associated behavioral changes. Although the child was completely normal clinically, the EEG findings persisted during a 9‐year‐follow‐up period. Ethosuximide (ESM) 1 gr daily resulted in temporary disappearance of the bioelectrical status. During the last 2 years without medication the EEG finding tended to be restricted to the posterior regions.
EEG and Seizure Outcome After Epilepsy Surgery
Authors: Patrick Suzanne , Berg Anne , Spencer Susan S.
Published: August 2005

Summary: The significance of the EEG after epilepsy surgery is not fully understood. We investigated the as‐ sociation between postoperative EEG abnormalities and persistent seizures after epilepsy surgery as they relate to pathologic lesions. Among 254 patients who underwent epilepsy surgery between 1987 and 1991, we identified 78 patients who had mesiotemporal sclerosis (MTS) and 47 patients who had low‐grade brain tumors, all of whom had 6‐to 18‐month postoperative follow‐up including EEG. Patients who had other pathology, multiple operations, callosotomy, or hemispherectomy, or who were aged <18 years or who had insufficient EEG data, were excluded. Patients were classified as having persistent seizures or being seizure‐free since operation. EEG abnormalities were abstracted from EEG reports 6–18 months postoperatively. Seizures persisted in 24% of the MTS group and in 27% of the tumor group. Of those with normal EEGs, none of the MTS patients and only 1 of the tumor patients had persistent seizures (p = 0.03 for MTS and p = 0.42 for tumor). Epileptiform discharges and focal slowing were associated with seizure persistence in both groups, but to a significant extent only in the MTS group. In the MTS group, patients who had both epileptiform discharges and focal slowing were more likely to have persistent seizures than were those with either abnormality alone.
Cytokine Production in Blood Mononuclear Cells from Epileptic Patients
Authors: Pacifici R. , Paris L. , Di Carlo S. , Bacosi A. , Pichini S. , Zuccaro P.
Published: August 2005

Summary Although convulsive disorders have been associated with immune abnormalities, little is known about cytokine production in epileptic patients. We evaluated the concentrations of interleukin‐1α (IL‐1α), interleukin‐1β (IL‐1β), interleukin‐2 (IL‐2), and interleukin‐6 (IL‐6) secreted by peripheral blood mononuclear cells (PBMC) from epileptic patients. The PBMC collected from epileptic patients, as compared with those of a control group, showed greater production of IL‐1α, IL‐1β, and IL‐6 in response to in vitro stimulation with mitogen. There was no statistical difference among patients treated with different antiepileptic drugs (AEDs). Significantly greater IL‐2 production was observed in PBMC from carbamazepine (CBZ)‐treated patients as compared with both the control group or with valproate and phenobarbital (PB)‐treated patients.
Clobazam in Long‐Term Epilepsy Treatment: Sustained Responders Versus Those Developing Tolerance
Authors: Singh Avinder , Guberman Alan H. , Boisvert Denis
Published: August 2005

Summary: Clobazam (CLB) is a structurally unique benzodiazepine (BZD) that has anticonvulsant activity in all types of refractory seizures. The main drawback to CLB, as to other BZDs, is the occurrence of tolerance. To date, there has been no way to predict which patients will develop tolerance. We compared clinical features and treatment variables between two groups of patients whose seizures were initially well controlled with CLB: patients with a sustained response and patients who developed tolerance. We retrospectively identified a group of 50 very good responders from among 173 consecutive patients with uncontrolled epilepsy treated with CLB. Very good responders were defined as patients with >75% reduction in seizures after the addition of CLB who continued CLB treatment for at least 1 month. At a mean follow‐up of 37.5 ± 12.8 months, 25 patients continued to respond and 25 developed tolerance (mean follow‐up 17.0 ± 15.7 months).Tolerance was defined as a relapse to a level <50% of pre‐CLB seizure frequency after an initial very good response for a minimum period of 1 month, despite constant CLB dose and, when available, serum levels. There was no change in concomitant medication. Significant differences were noted between the two groups. The sustained response group had a shorter duration of epilepsy (mean 16.5 vs.24.5 years, p = 0.015), a greater proportion of individuals with a known etiology for their epilepsy (48 vs.16%, p = 0.006), and higher CLB levels (0.50 vs.0.22 μM, p = 0.017), but no significant difference in N‐desmethyl‐CLB levels. Certain factors apparently may influence the likelihood of developing tolerance to the antiepileptic effects of clobazam.
Idiopathic Photosensitive Occipital Lobe Epilepsy
Authors: Guerrini Renzo , Dravet Charlotte , Genton Pierre , Bureau Michelle , Bonanni Paolo , Ferrari Anna Rita , Roger Joseph
Published: August 2005

Summary: We studied 10 neurologically normal patients (8 females, 2 males) aged 8–30 years (mean 17 years) who had recurrent episodes of visually induced occipital seizures. Television and computer screens were the main triggers. Seizure onset occurred between the ages of 5 and 17 years (mean 11 years). All seizures were stimulus related and began with elementary visual symptoms, followed in most patients by a slow clustering of cephalicpain, epigastric discomfort, and vomiting, with either normal or only mildly impaired responsiveness. EEG fea‐tures included normal background activity, occipital spikes and waves, and a photoparoxysmal response which could be occipital, generalized, or both. Four pa‐tients also showed spontaneous generalized epileptiform abnormalities, and 3 had rolandic spikes. An Oz electrode was critical in identifying epileptiform activity in some patients. Complete seizure control was achieved in most patients with monotherapy, although occasional stimulus‐related seizures occurred in 3 patients who showed a wider range of photosensitivity. These patients have an idiopathic localization‐related epilepsy with age‐related onset and specific mode of precipitation. Although this type of epilepsy has been reported previously, it has remained underrecognized, probably because it is difficult to differentiate clinically from migraine or from nonreflex childhood idiopathic occipital epilepsy.
Alteration in Levels of Expression of Brain Calbindin D‐28k and Calretinin mRNA in Genetically Epilepsy‐Prone Rats
Authors: Montpied Pascale , Winsky Lois , Dailey John W. , Jobe Phillip C. , Jacobowitz David M.
Published: August 2005

Summary: Variations in the concentration of free calcium in neurons is believed to play a major role in regulating neuronal excitability. Because calcium‐binding proteins such as calbindin D‐28k and calretinin help to regulate intracellular calcium, we investigated the possibility that the expression of these proteins may be affected in genetically epilepsy‐prone rats (GEPRs). The mRNA levels of both proteins were compared across several brain regions using in situ hybridization histochemistry and Northern blot analysis with semiquantitation by optical density measures on autoradiograms from two GEPR strains that differ in the severity of audiogenic seizures (GEPR9 and GEPR3) and from Sprague‐Dawley rats. Results revealed a lower level of expression in calbindin D‐28k mRNA in the caudate putamen‐accumbens nuclei in GEPR3 (‐30%) and GEPR9 (‐60%) relative to controls. The calbindin D‐28k mRNA level was also lower in the reuniens nucleus of the thalamus (‐41% in GEPR3; ‐34% in GEPR9). The calretinin mRNA level was lower in the substantia nigra compacta of both GEPR rat strains (‐31% in GEPR3 and ‐34% in GEPR9 relative to controls). No changes in mRNA were detected in other brain regions expressing calbindin D‐28k or calretinin mRNA. These results indicate that the expression of these related calcium‐binding proteins is altered in the GEPRs before the induction of seizures. This initial defect could alter either the calcium‐buffering capacity or regulation of calcium‐mediated processes by these proteins and thus play a role in the molecular cascade of events inducing the genetic susceptibility to, and the generalization of, seizures in these rat strains.
Comparison of Anticonvulsant Efficacy of Valproate During Prolonged Treatment with One and Three Daily Doses or Continuous (“Controlled Release”) Administration in a Model of Generalized Seizures in Rats
Authors: Löscher Wolfgang , Hönack Dagmar
Published: August 2005

Summary: Recently, sustained‐release (SR) preparations of valproate (VPA) have been developed to minimize or prevent problems associated with plasma level fluctuations during therapy with conventional preparations. In the present experiments, the anticonvulsant activity of VPA was assessed during prolonged treatment with different administration protocols using the intravenous (i.v.) pentylenetetrazol (PTZ)‐infusion seizure threshold model in rats. To simulate a controlled‐release (CR) preparation, VPA was infused at a constant rate through chronically implanted intrajugular catheters in some of the experiments. In all experiments, the PTZ seizure threshold was repeatedly determined in individual rats with chronically implanted intrajugular catheters at daily intervals. Injection of saline three times daily in a control group showed that the PTZ seizure threshold was stable throughout the experiment. Acute administration of VPA 200 mg/kg intraperitoneally (i.p.) significantly increased the seizure threshold. During prolonged treatment with three daily doses of 200 mg/kg i.p., anticonvulsant activity markedly increased on the second day of treatment and thereafter compared to the acute effect of VPA, although plasma levels measured at each seizure threshold determination did not differ significantly. This increase in anticonvulsant activity of VPA during prolonged treatment was much less pronounced with one instead of three daily doses. One daily intraperitoneal injection of VPA (200 mg/kg) plus continuous, constant‐rate intravenous infusion of 400 mg/kg/day led to a marked increase in anticonvulsant activity similar to that in the experiment with three daily doses, indicating that not the peak levels but the duration of maintenance of active drug concentrations was important for development of enhanced anticonvulsant activity. Continuous constant‐rate intravenous infusion of VPA (600 mg/kg/day) without additional bolus injections led to significant increases in seizure threshold for the duration of treatment, although drug levels at time of threshold determination were much lower as compared with those in the experiments with conventional administration, confirming that high peak levels of VPA are not needed for development of anticonvulsant efficacy. In contrast to the experiments with single‐dose injections, continuous infusion of VPA was the only treatment devoid of behavioral adverse effects. The experiments indicate that CR preparations of VPA lead to anticonvulsant efficacy of VPA in the absence of high peak levels in plasma and the adverse effects (AE) associated with such peak levels.
Complex Febrile Seizures
Authors: Berg Anne T. , Shinnar Shlomo
Published: August 2005

In the context of a prospective cohort study, we examined the associations between individual complex features of both first (n = 428) and recurrent (n = 240) febrile seizures and factors shown to predict outcome in children with febrile seizures. Thirty‐five percent of first and 33% of recurrent febrile seizures had one or more complex features (focal onset, duration ≥10 min, or multiple seizures during the illness episode). There were strong correlations between focality and prolonged duration for both first and recurrent febrile seizures. A low fever at the time of the seizure was marginally associated with prolonged duration. Most factors associated with either recurrent febrile seizures or subsequent unprovoked seizures were not associated with either the initial seizure being complex or the likelihood that a recurrence would be complex. However, in children with recurrent febrile seizures, complex features tended to repeat. This factor was statistically significant and particularly striking for prolonged duration. Genetic or other constitutional factors may explain why the prolonged feature recurs. Eleven (2.5%) children had three or four risk factors for recurrent febrile seizures and a first febrile seizure that was prolonged. Eight (72.7%) of them experienced a recurrent febrile seizure that was prolonged. This very small group of children may be candidates for abortive therapy to be administered at the onset of a recurrent seizure.
Cortical Benzodiazepine Receptor Changes are Related to Frequency of Partial Seizures: A Positron Emission Tomography Study
Authors: Savic Ivanka , Svanborg E. , Thorell J. O.
Published: August 2005

Measurements of benzodiazepine (BZD) receptor density with positron emission tomography (PET) are a promising method of identifying and localizing epileptogenic regions. We investigated whether the pattern of BZD receptor changes depends on seizure frequency, studying 19 patients with matching seizure semiology but different rates of seizure occurrence, using [11C] flumaze‐nil as the ligand. All patients had partial epilepsy and normal magnetic resonance imaging (MRI) of the brain. The visually determined PET focus, characterized by reduced BZD receptor density, corresponded to the epileptogenic focuslseizure onset region in all patients. The degree of BZD receptor reduction showed a positive correlation with seizure frequency. Patients with daily seizures differed from those with fewer seizures in two aspects: (a) the degree and extent of BZD receptor reduction was more pronounced, and (b) BZD receptors were also reduced in the primary projection areas of the focus. Flumazenil‐PET reliably identifies epileptogenic brain regions in patients with partial seizures. In addition, flurna‐zenil‐PET can distinguish patients with frequent seizures. The method therefore is not only suitable for noninvasive localization of the seizure focus, but also may provide a biochemical marker of epileptogenicity.
Comparison Between One and Three Years of Treatment in Uncomplicated Childhood Epilepsy: A Prospective Study. I. Outcome in Different Seizure Types
Authors: Braathen Gunnar , Anderson Thomas , Gylje Hans , Melander Hans , Naglo Anna‐Stina , Noren Lars , Person Anders , Rane Anders , Sjörs Kerstin , Theorell Klas , Wigertz Alf
Published: August 2005

Summary: Purpose: The main purpose of this prospective study was to analyze whether 1 year of treatment was as effective as 3 years with respect to remission rate in children with idiopathic epilepsy.

Methods: Treatment for epileptic seizures was started in 207 children aged 2–16 years. They were randomized to treatment for I or 3 years. At the end of the predetermined treatment period, 161 children had been seizure‐free for 6 months and the treatment could be gradually withdrawn.

Results: The overall remission rate in our group of patients was significantly higher (71%) in the group treated for 3 years than in the group treated for 1 year (53%). However, comparison of remission rates between patients with different seizure types showed statistically significant differences in outcome depending on duration of treatment only in children with complex partial seizures (CPS).

Conclusions: Our results show that 1 year of treatment can be recommended in children with benign partial epilepsy with rolandic spikes (BECT) and in children with simple partial seizures (SPS) but is clearly insufficient in children with CPS. A proper seizure classification is one important tool, although not sufficient, in offering recommendations concerning the duration of treatment in children with idiopathic epilepsy.